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Sample records for thermosensitive peg-pcl-peg hydrogel

  1. Nanobody-functionalized PEG-b-PCL polymersomes and their targeting study.

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    Zou, Tao; Dembele, Fatimata; Beugnet, Anne; Sengmanivong, Lucie; Trepout, Sylvain; Marco, Sergio; de Marco, Ario; Li, Min-Hui

    2015-11-20

    We prepared and characterized polymersomes functionalized with nanobodies (VHHs) on the basis of biocompatible, biodegradable and FDA-approved poly(ethylene glycol)-block-poly(ϵ-caprolactone) (PEG-b-PCL). Fluorescein isothiocyanate (FITC) and N-beta-maleimidopropyl-oxysuccinimide ester were allowed reacting with H2N-PEG-b-PCL to produce FITC and maleimide (Mal) functionalized copolymers, Mal-PEG-b-PCL and FITC-PEG-b-PCL. A mixture of MeO-PEG-b-PCL, Mal-PEG-b-PCL and FITC-PEG-b-PCL was used to prepare polymersomes by thin film hydration and nanoprecipitation methods. Morphological studies by cryogenic transmission electron microscopy (Cryo-TEM) showed that the nanoparticles exhibited predominantly vesicular structures (polymersomes). Their mean diameters measured by dynamic light scattering were around 150 nm and the zeta-potentials around -1 mV at pH 7.4. The nanoparticles were functionalized with either anti-HER2 (VHH1) or anti-GFP (VHH2) nanobodies using maleimide-cysteine chemistry. Their particle size and zeta-potential increased slightly after nanobody-functionalization. The specific binding of VHH-functionalized polymersomes and control nanoparticles towards HER2 positive breast cancer cells was analyzed by flow cytometry and confocal microscopy. The collected results represent the first report which experimentally demonstrates that VHH1-functionalized PEO-b-PCL polymersomes can target specifically breast cancer cells expressing HER2 receptors. The detailed morphological and cell-binding studies described herein pave the way for future in vivo studies to evaluate the feasibility to use such nanoparticles for targeted drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Bactericidal Effect of Lauric Acid-Loaded PCL-PEG-PCL Nano-Sized Micelles on Skin Commensal Propionibacterium acnes

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    Thi-Quynh-Mai Tran

    2016-08-01

    Full Text Available Acne is the over growth of the commensal bacteria Propionibacterium acnes (P. acnes on human skin. Lauric acid (LA has been investigated as an effective candidate to suppress the activity of P. acnes. Although LA is nearly insoluble in water, dimethyl sulfoxide (DMSO has been reported to effectively solubilize LA. However, the toxicity of DMSO can limit the use of LA on the skin. In this study, LA-loaded poly(ɛ-caprolactone-poly(ethylene glycol-poly(ɛ-caprolactone micelles (PCL-PEG-PCL were developed to improve the bactericidal effect of free LA on P. acnes. The block copolymers mPEG-PCL and PCL-PEG-PCL with different molecular weights were synthesized and characterized using 1H Nuclear Magnetic Resonance spectroscopy (1H NMR, Fourier-transform infrared spectroscopy (FT-IR, Gel Permeation Chromatography (GPC, and Differential Scanning Calorimetry (DSC. In the presence of LA, mPEG-PCL diblock copolymers did not self-assemble into nano-sized micelles. On the contrary, the average particle sizes of the PCL-PEG-PCL micelles ranged from 50–198 nm for blank micelles and 27–89 nm for LA-loaded micelles. The drug loading content increased as the molecular weight of PCL-PEG-PCL polymer increased. Additionally, the minimum inhibitory concentration (MIC and the minimum bactericidal concentration (MBC of free LA were 20 and 80 μg/mL, respectively. The MICs and MBCs of the micelles decreased to 10 and 40 μg/mL, respectively. This study demonstrated that the LA-loaded micelles are a potential treatment for acne.

  3. Pharmacokinetics and in vivo delivery of curcumin by copolymeric mPEG-PCL micelles.

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    Kheiri Manjili, Hamidreza; Ghasemi, Parisa; Malvandi, Hojjat; Mousavi, Mir Sajjad; Attari, Elahe; Danafar, Hossein

    2017-07-01

    Curcumin (CUR) has been associated with anti-inflammatory, antimicrobial, antioxidant, anti-amyloid, and antitumor effects, but its application is limited because of its low aqueous solubility and poor oral bioavailability. To progress the bioavailability and water solubility of CUR, we synthesized five series of mono methoxy poly (ethylene glycol)-poly (ε-caprolactone) (mPEG-PCL) diblock copolymers. The structure of the copolymers was characterized by H NMR, FTIR, DSC and GPC techniques. In this study, CUR was encapsulated within micelles through a single-step nano-precipitation method, leading to formation of CUR-loaded mPEG-PCL (CUR/mPEG-PCL) micelles. The resulting micelles were characterized further by various techniques such as dynamic light scattering (DLS) and atomic force microscopy (AFM). The cytotoxicity of void CUR, mPEG-PCL and CUR/mPEG-PCL micelles was compared to each other by performing MTT assay of the treated MCF-7 and 4T1 cell line. Study of the in vivo pharmacokinetics of the CUR-loaded micelles was also carried out on selected copolymers in comparison with CUR solution formulations. The results showed that the zeta potential of CUR-loaded micelles was about -11.5mV and the average size was 81.0nm. CUR was encapsulated into mPEG-PCL micelles with loading capacity of 20.65±0.015% and entrapment efficiency of 89.32±0.34%. The plasma AUC (0-t), t 1/2 and C max of CUR micelles were increased by 52.8, 4.63 and 7.51-fold compared to the CUR solution, respectively. In vivo results showed that multiple injections of CUR-loaded micelles could prolong the circulation time and increase the therapeutic efficacy of CUR. These results suggested that mPEG-PCL micelles would be a potential carrier for CUR. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. PEG-b-PCL polymeric nano-micelle inhibits vascular angiogenesis by activating p53-dependent apoptosis in zebrafish.

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    Zhou, Tian; Dong, Qinglei; Shen, Yang; Wu, Wei; Wu, Haide; Luo, Xianglin; Liao, Xiaoling; Wang, Guixue

    Micro/nanoparticles could cause adverse effects on cardiovascular system and increase the risk for cardiovascular disease-related events. Nanoparticles prepared from poly(ethylene glycol) (PEG)- b -poly( ε -caprolactone) (PCL), namely PEG- b -PCL, a widely studied biodegradable copolymer, are promising carriers for the drug delivery systems. However, it is unknown whether polymeric PEG- b -PCL nano-micelles give rise to potential complications of the cardiovascular system. Zebrafish were used as an in vivo model to evaluate the effects of PEG- b -PCL nano-micelle on cardiovascular development. The results showed that PEG- b -PCL nano-micelle caused embryo mortality as well as embryonic and larval malformations in a dose-dependent manner. To determine PEG- b -PCL nano-micelle effects on embryonic angiogenesis, a critical process in zebrafish cardiovascular development, growth of intersegmental vessels (ISVs) and caudal vessels (CVs) in flk1-GFP transgenic zebrafish embryos using fluorescent stereomicroscopy were examined. The expression of fetal liver kinase 1 (flk1), an angiogenic factor, by real-time quantitative polymerase chain reaction (qPCR) and in situ whole-mount hybridization were also analyzed. PEG- b -PCL nano-micelle decreased growth of ISVs and CVs, as well as reduced flk1 expression in a concentration-dependent manner. Parallel to the inhibitory effects on angiogenesis, PEG- b -PCL nano-micelle exposure upregulated p53 pro-apoptotic pathway and induced cellular apoptosis in angiogenic regions by qPCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay. This study further showed that inhibiting p53 activity, either by pharmacological inhibitor or RNA interference, could abrogate the apoptosis and angiogenic defects caused by PEG- b -PCL nano-micelles, indicating that PEG- b -PCL nano-micelle inhibits angiogenesis by activating p53-mediated apoptosis. This study indicates that polymeric PEG- b -PCL nano-micelle could

  5. Synthesis, characterization and in vitro evaluation of magnetic nanoparticles modified with PCL-PEG-PCL for controlled delivery of 5FU.

    Science.gov (United States)

    Asadi, Nahideh; Annabi, Nasim; Mostafavi, Ebrahim; Anzabi, Maryam; Khalilov, Rovshan; Saghfi, Siamak; Mehrizadeh, Masoud; Akbarzadeh, Abolfazl

    2018-02-22

    Magnetic nanoparticles have properties that cause to apply them in cancer therapy and vehicles for the delivery of drugs such as 5FU, especially when they are modified with biocompatible copolymers. The aim of this study is to modify superparamagnetic iron oxide nanoparticles (SPIONPs) with PCL-PEG-PCL copolymers and then utilization of these nanoparticles for encapsulation of anticancer drug 5FU. The ring-opening polymerization (ROP) was used for the synthesis of PCL-PEG-PCL copolymer by ε-caprolactone (PCL) and polyethylene glycol (PEG2000). We used the double emulsion method (water/oil/water) to prepare 5FU-encapsulated Fe 3 O 4 magnetic nanoparticles modified with PCL-PEG-PCL copolymer. Chemical structure and magnetic properties of 5FU-loaded magnetic-polymer nanoparticles were investigated systematically by employing FT-IR, XRD, VSM and SEM techniques. In vitro release profile of 5FU-loaded NPs was also determined. The results showed that the encapsulation efficiency value for nanoparticles were 90%. Moreover, the release of 5FU is significantly higher at pH 5.8 compared to pH 7.4. Therefore, these nanoparticles have sustained release and can apply for cancer therapy.

  6. Therapeutic application of injectable thermosensitive hydrogel in preventing local breast cancer recurrence and improving incision wound healing in a mouse model

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    Lei, Na; Gong, Changyang; Qian, Zhiyong; Luo, Feng; Wang, Cheng; Wang, Helan; Wei, Yuquan

    2012-08-01

    Many drug delivery systems (DDSs) have been investigated for local targeting of malignant disease with the intention of increasing anti-tumor activity and minimizing systemic toxicity. An injectable thermosensitive hydrogel was applied to prevent locoregional recurrence of 4T1 breast cancer in a mouse model. The presented hydrogel, which is based on poly(ethyleneglycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE), flows freely at normal temperature, forms a gel within seconds in situ at body temperature, and eventually releases the drug in a consistent and sustained fashion as it gradually biodegrades. Locoregional recurrence after primary tumor removal was significantly inhibited in mice treated with the paclitaxel (PTX)-loaded PECE hydrogel subcutaneously (9.1%) administered, compared with the blank hydrogel (80.0%), systemic (77.8%) and locally (75.0%) administered PTX, and the control group (100%) (P 0.05), in agreement with histopathological examinations. This novel DDSs represents a promising approach for local adjuvant therapy in malignant disease.

  7. Pharmacokinetic properties and antitumor efficacy of the 5-fluorouracil loaded PEG-hydrogel

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    Kim Bokyung

    2010-05-01

    Full Text Available Abstract Background We have studied the in vitro and in vivo utility of polyethylene glycol (PEG-hydrogels for the development of an anticancer drug 5-fluorouracil (5-FU delivery system. Methods A 5-FU-loaded PEG-hydrogel was implanted subcutaneously to evaluate the drug retention time and the anticancer effect. For the pharmacokinetic study, two groups of male rats were administered either an aqueous solution of 5-FU (control group/or a 5-FU-loaded PEG-hydrogel (treated group at a dose of 100 mg/kg. For the pharmacodynamic study, a human non-small-cell lung adenocarcinoma (NSCLC cell line, A549 was inoculated to male nude mice with a cell density of 3 × 106. Once tumors start growing, the mice were injected with 5-FU/or 5-FU-loaded PEG-hydrogel once a week for 4 weeks. The growth of the tumors was monitored by measuring the tumor volume and calculating the tumor inhibition rate (IR over the duration of the study. Results In the pharmacokinetic study, the 5-FU-loaded PEG-hydrogel gave a mean residence time (MRT of 8.0 h and the elimination half-life of 0.9 h; these values were 14- and 6-fold, respectively, longer than those for the free solution of 5-FU (p Conclusion We suggest that 5-FU-loaded PEG-hydrogels could provide a useful tool for the development of an anticancer drug delivery system.

  8. PSMA ligand conjugated PCL-PEG polymeric micelles targeted to prostate cancer cells.

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    Jian Jin

    Full Text Available In this content, a small molecular ligand of prostate specific membrane antigen (SMLP conjugated poly (caprolactone (PCL-b-poly (ethylene glycol (PEG copolymers with different block lengths were synthesized to construct a satisfactory drug delivery system. Four different docetaxel-loaded polymeric micelles (DTX-PMs were prepared by dialysis with particle sizes less than 60 nm as characterized by dynamic light scattering (DLS and transmission electron microscope (TEM. Optimization of the prepared micelles was conducted based on short-term stability and drug-loading content. The results showed that optimized systems were able to remain stable over 7 days. Compared with Taxotere, DTX-PMs with the same ratio of hydrophilic/hydrophobic chain length displayed similar sustained release behaviors. The cytotoxicity of the optimized targeted DTX-PCL12K-PEG5K-SMLP micelles (DTX-PMs2 and non-targeted DTX-PCL12K-mPEG5K micelles (DTX-PMs1 were evaluated by MTT assays using prostate specific membrane antigen (PSMA positive prostate adenocarcinoma cells (LNCaP. The results showed that the targeted micelles had a much lower IC50 than their non-targeted counterparts (48 h: 0.87 ± 0.27 vs 13.48 ± 1.03 µg/ml; 72 h: 0.02 ± 0.008 vs 1.35 ± 0.54 µg/ml. In vitro cellular uptake of PMs2 showed 5-fold higher fluorescence intensity than that of PMs1 after 4 h incubation. According to these results, the novel nano-sized drug delivery system based on DTX-PCL-PEG-SMLP offers great promise for the treatment of prostatic cancer.

  9. Doxorubicin-Loaded PEG-PCL-PEG Micelle Using Xenograft Model of Nude Mice: Effect of Multiple Administration of Micelle on the Suppression of Human Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cuong, Nguyen-Van [Department of Biomedical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd., Chung Li, Taiwan (China); Department of Chemical Engineering, Ho Chi Minh City University of Industry, 12 Nguyen Van Bao St, Ho Chi Minh (Viet Nam); Jiang, Jian-Lin; Li, Yu-Lun [Department of Biomedical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd., Chung Li, Taiwan (China); Chen, Jim-Ray [Department of Pathology, Chang Gung Memorial Hospital at Keelung, Taiwan and Chang Gung University, College of Medicine, Taoyuan, Taiwan (China); Jwo, Shyh-Chuan [Division of General Surgery, Chang Gung Memorial Hospital at Keelung, Taiwan and Chang Gung University, College of Medicine, Taoyuan, Taiwan (China); Hsieh, Ming-Fa, E-mail: mfhsieh@cycu.edu.tw [Department of Biomedical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd., Chung Li, Taiwan (China)

    2010-12-28

    The triblock copolymer is composed of two identical hydrophilic segments Monomethoxy poly(ethylene glycol) (mPEG) and one hydrophobic segment poly(ε-caprolactone) (PCL); which is synthesized by coupling of mPEG-PCL-OH and mPEG-COOH in a mild condition using dicyclohexylcarbodiimide and 4-dimethylamino pyridine. The amphiphilic block copolymer can self-assemble into nanoscopic micelles to accommodate doxorubixin (DOX) in the hydrophobic core. The physicochemical properties and in vitro tests, including cytotoxicity of the micelles, have been characterized in our previous study. In this study, DOX was encapsulated into micelles with a drug loading content of 8.5%. Confocal microscopy indicated that DOX was internalized into the cytoplasm via endocystosis. A dose-finding scheme of the polymeric micelle (placebo) showed a safe dose of PEG-PCL-PEG micelles was 71.4 mg/kg in mice. Importantly, the circulation time of DOX-loaded micelles in the plasma significantly increased compared to that of free DOX in rats. A biodistribution study displayed that plasma extravasation of DOX in liver and spleen occurred in the first four hours. Lastly, the tumor growth of human breast cancer cells in nude mice was suppressed by multiple injections (5 mg/kg, three times daily on day 0, 7 and 14) of DOX-loaded micelles as compared to multiple administrations of free DOX.

  10. Doxorubicin-Loaded PEG-PCL-PEG Micelle Using Xenograft Model of Nude Mice: Effect of Multiple Administration of Micelle on the Suppression of Human Breast Cancer

    International Nuclear Information System (INIS)

    Cuong, Nguyen-Van; Jiang, Jian-Lin; Li, Yu-Lun; Chen, Jim-Ray; Jwo, Shyh-Chuan; Hsieh, Ming-Fa

    2010-01-01

    The triblock copolymer is composed of two identical hydrophilic segments Monomethoxy poly(ethylene glycol) (mPEG) and one hydrophobic segment poly(ε-caprolactone) (PCL); which is synthesized by coupling of mPEG-PCL-OH and mPEG-COOH in a mild condition using dicyclohexylcarbodiimide and 4-dimethylamino pyridine. The amphiphilic block copolymer can self-assemble into nanoscopic micelles to accommodate doxorubixin (DOX) in the hydrophobic core. The physicochemical properties and in vitro tests, including cytotoxicity of the micelles, have been characterized in our previous study. In this study, DOX was encapsulated into micelles with a drug loading content of 8.5%. Confocal microscopy indicated that DOX was internalized into the cytoplasm via endocystosis. A dose-finding scheme of the polymeric micelle (placebo) showed a safe dose of PEG-PCL-PEG micelles was 71.4 mg/kg in mice. Importantly, the circulation time of DOX-loaded micelles in the plasma significantly increased compared to that of free DOX in rats. A biodistribution study displayed that plasma extravasation of DOX in liver and spleen occurred in the first four hours. Lastly, the tumor growth of human breast cancer cells in nude mice was suppressed by multiple injections (5 mg/kg, three times daily on day 0, 7 and 14) of DOX-loaded micelles as compared to multiple administrations of free DOX

  11. Poly(ethylene glycol) (PEG)-lactic acid nanocarrier-based degradable hydrogels for restoring the vaginal microenvironment

    Science.gov (United States)

    Rajan, Sujata Sundara; Turovskiy, Yevgeniy; Singh, Yashveer; Chikindas, Michael L.; Sinko, Patrick J.

    2014-01-01

    Women with bacterial vaginosis (BV) display reduced vaginal acidity, which make them susceptible to associated infections such as HIV. In the current study, poly(ethylene glycol) (PEG) nanocarrier-based degradable hydrogels were developed for the controlled release of lactic acid in the vagina of BV-infected women. PEG-lactic acid (PEG-LA) nanocarriers were prepared by covalently attaching lactic acid to 8-arm PEG-SH via cleavable thioester bonds. PEG-LA nanocarriers with 4 copies of lactic acid per molecule provided controlled release of lactic acid with a maximum release of 23% and 47% bound lactic acid in phosphate buffered saline (PBS, pH 7.4) and acetate buffer (AB, pH 4.3), respectively. The PEG nanocarrier-based hydrogels were formed by cross-linking the PEG-LA nanocarriers with 4-arm PEG-NHS via degradable thioester bonds. The nanocarrier-based hydrogels formed within 20 min under ambient conditions and exhibited an elastic modulus that was 100-fold higher than the viscous modulus. The nanocarrier-based degradable hydrogels provided controlled release of lactic acid for several hours; however, a maximum release of only 10%–14% bound lactic acid was observed possibly due to steric hindrance of the polymer chains in the cross-linked hydrogel. In contrast, hydrogels with passively entrapped lactic acid showed burst release with complete release within 30 min. Lactic acid showed antimicrobial activity against the primary BV pathogen Gardnerella vaginalis with a minimum inhibitory concentration (MIC) of 3.6 mg/ml. In addition, the hydrogels with passively entrapped lactic acid showed retained antimicrobial activity with complete inhibition G. vaginalis growth within 48 h. The results of the current study collectively demonstrate the potential of PEG nanocarrier-based hydrogels for vaginal administration of lactic acid for preventing and treating BV. PMID:25223229

  12. Effect of Zebularine loaded MePEG-PCL nanoparticles on viability, attachment of in vitro cultured lens epithelial cells

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    Si-Wei Liu

    2015-01-01

    Full Text Available AIM: To investigate the effect of zebularine(Zebloaded Poly(ethylene glycol-block-poly(ε-caprolactonemethyl ether(MePEG-PCLnanoparticles(NPson the viability, attachment, and apoptosis of in vitro cultured lens epithelial cells(LECs. METHODS: In vitro cultured infant human lens tissue HLE B-3 immortalized cells were distributed randomly divided into six groups. Each group was administered with free Zeb 50μmol/L(ZebF1 group, 100μmol/L(ZebF2 group, Zeb -loaded MePEG-PCL NPs 50μmol/L(ZebNP1 group, Zeb -loaded MePEG-PCL NPs 100μmol/L(ZebNP2 group, MePEG-PCL empty NPs(NPs groupor blank medium(group Crespectively. A tetrazolium dye assay(MTTtest and modified MTT test were performed to determine cell viability and cell attachment. DNA ladder was used to detect the cell apoptosis. RESULTS: Determined by MTT colorimetric method: Cell proliferation rate of LECs were suppressed by all Zeb administration groups in a concentration-time dependent manner(PPP ZebNP1>ZebF2(PCONCLUSION: Zeb loaded MePEG-PCL NPs had better effect on suppressing the viability and attachment of in vitro cultured LECs than the free Zeb groups, as well as enhancing the apoptosis.

  13. Doxorubicin-Loaded PEG-PCL-PEG Micelle Using Xenograft Model of Nude Mice: Effect of Multiple Administration of Micelle on the Suppression of Human Breast Cancer

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    Ming-Fa Hsieh

    2010-12-01

    Full Text Available The triblock copolymer is composed of two identical hydrophilic segments: Monomethoxy poly(ethylene glycol (mPEG and one hydrophobic segment poly(ε‑caprolactone (PCL; which is synthesized by coupling of mPEG-PCL-OH and mPEG‑COOH in a mild condition using dicyclohexylcarbodiimide and 4-dimethylamino pyridine. The amphiphilic block copolymer can self-assemble into nanoscopic micelles to accommodate doxorubixin (DOX in the hydrophobic core. The physicochemical properties and in vitro tests, including cytotoxicity of the micelles, have been characterized in our previous study. In this study, DOX was encapsulated into micelles with a drug loading content of 8.5%. Confocal microscopy indicated that DOX was internalized into the cytoplasm via endocystosis. A dose-finding scheme of the polymeric micelle (placebo showed a safe dose of PEG-PCL-PEG micelles was 71.4 mg/kg in mice. Importantly, the circulation time of DOX-loaded micelles in the plasma significantly increased compared to that of free DOX in rats. A biodistribution study displayed that plasma extravasation of DOX in liver and spleen occurred in the first four hours. Lastly, the tumor growth of human breast cancer cells in nude mice was suppressed by multiple injections (5 mg/kg, three times daily on day 0, 7 and 14 of DOX-loaded micelles as compared to multiple administrations of free DOX.

  14. Photocrosslinked nanocomposite hydrogels from PEG and silica nanospheres: Structural, mechanical and cell adhesion characteristics

    International Nuclear Information System (INIS)

    Gaharwar, Akhilesh K.; Rivera, Christian; Wu, Chia-Jung; Chan, Burke K.; Schmidt, Gudrun

    2013-01-01

    Photopolymerized hydrogels are extensively investigated for various tissue engineering applications, primarily due to their ability to form hydrogels in a minimally invasive manner. Although photocrosslinkable hydrogels provide necessary biological and chemical characteristics to mimic cellular microenvironments, they often lack sufficient mechanical properties. Recently, nanocomposite approaches have demonstrated potential to overcome these deficits by reinforcing the hydrogel network with. In this study, we investigate some physical, chemical, and biological properties of photocrosslinked poly(ethylene glycol) (PEG)-silica hydrogels. The addition of silica nanospheres significantly suppresses the hydration degree of the PEG hydrogels, indicating surface interactions between the silica nanospheres and the polymer chains. No significant change in hydrogel microstructure or average pore size due to the addition of silica nanospheres was observed. However, addition of silica nanospheres significantly increases both the mechanical strength and the toughness of the hydrogel networks. The biological properties of these nanocomposite hydrogels were evaluated by seeding fibroblast cells on the hydrogel surface. While the PEG hydrogels showed minimum cell adhesion, spreading and proliferation, the addition of silica nanospheres enhanced initial cell adhesion, promoted cell spreading and increased the metabolic activity of the cells. Overall, results indicate that the addition of silica nanospheres improves the mechanical stiffness and cell adhesion properties of PEG hydrogels and can be used for biomedical applications that required controlled cell adhesion. - Graphical abstract: Structural, mechanical and biological properties of photocrosslinked nanocomposite hydrogels from silica and poly(ethylene oxide) are investigated. Silica reinforce the hydrogel network and improved mechanical strength. Addition of induces cell adhesion characteristic properties for various

  15. Acetal-Linked Paclitaxel Polymeric Prodrug Based on Functionalized mPEG-PCL Diblock Polymer for pH-Triggered Drug Delivery

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    Yinglei Zhai

    2017-12-01

    Full Text Available The differences in micro-environment between cancer cells and the normal ones offer the possibility to develop stimuli-responsive drug-delivery systems for overcoming the drawbacks in the clinical use of anticancer drugs, such as paclitaxel, doxorubicin, and etc. Hence, we developed a novel endosomal pH-sensitive paclitaxel (PTX prodrug micelles based on functionalized poly(ethylene glycol-poly(ε-caprolactone (mPEG-PCL diblock polymer with an acid-cleavable acetal (Ace linkage (mPEG-PCL-Ace-PTX. The mPEG-PCL-Ace-PTX5 with a high drug content of 23.5 wt % was self-assembled in phosphate buffer (pH 7.4, 10 mM into nanosized micelles with an average diameter of 68.5 nm. The in vitro release studies demonstrated that mPEG-PCL-Ace-PTX5 micelles was highly pH-sensitive, in which 16.8%, 32.8%, and 48.2% of parent free PTX was released from mPEG-PCL-Ace-PTX5 micelles in 48 h at pH 7.4, 6.0, and 5.0, respectively. Thiazolyl Blue Tetrazolium Bromide (MTT assays suggested that the pH-sensitive PTX prodrug micelles displayed higher therapeutic efficacy against MCF-7 cells compared with free PTX. Therefore, the PTX prodrug micelles with acetal bond may offer a promising strategy for cancer therapy.

  16. Construction of non-viral vector (mPEG5k-PCL1.2k)1.4-g-PEI10k and its gene delivery efficacy in vitro

    OpenAIRE

    Wei HUANG; Ming LV; Zhong-gao GAO; Ming-ji JIN; Fei-fei YANG; Yu-li WANG

    2011-01-01

    Objective To construct(mPEG5k-PCL1.2k)1.4-g-PEI10k,a copolymer designed as delivery vector for non-viral gene therapy,and explore its cytotoxicity and efficacy in delivery of plasmid DNA(pDNA).Methods The copolymer,mPEG5k-PCL1.2k-OH,was prepared by ring-opening polymerization and then followed by a conversion of hydroxyl terminal(-OH) into N-hydroxysuccinimide(NHS) to prepare mPEG5k-PCL1.2k-NHS.One of the branches,PEI10k,was then reacted with mPEG5k-PCL1.2k-NHS to synthesize a ternary copolym...

  17. PEG-based degradable networks for drug delivery applications

    Science.gov (United States)

    Ostroha, Jamie L.

    The controlled delivery of therapeutic agents by biodegradable hydrogels has become a popular mechanism for drug administration in recent years. Hydrogels are three-dimensional networks of polymer chains held together by crosslinks. Although the changes which the hydrogel undergoes in solution are important to a wide range of experimental studies, they have not been investigated systematically and the factors which influence the degree of swelling have not been adequately described. Hydrogels made of poly(ethylene glycol) (PEG) will generally resist degradation in aqueous conditions, while a hydrogel made from a copolymer of poly(lactic acid) (PLA) and PEG will degrade via hydrolysis of the lactic acid group. This ability to degrade makes these hydrogels promising candidates for controlled release drug delivery systems. The goal of this research was to characterize the swelling and degradation of both degradable and non-degradable gels and to evaluate the release of different drugs from these hydrogels, where the key variable is the molecular weight of the PEG segment. These hydrogels were formed by the addition and subsequent chemically crosslinking of methacrylate end groups. During crosslinking, both PEG and LA-PEG-LA hydrogels of varied PEG molecular weight were loaded with Vitamin B12, Insulin, Haloperidol, and Dextran. It was shown that increasing PEG molecular weight produces a hydrogel with larger pores, thus increasing water uptake and degradation rate. While many environmental factors do not affect the swelling behavior, they do significantly impact the degradation of the hydrogel, and thus the release of incorporated therapeutic agents.

  18. PVA-PEG physically cross-linked hydrogel film as a wound dressing: experimental design and optimization.

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    Ahmed, Afnan Sh; Mandal, Uttam Kumar; Taher, Muhammad; Susanti, Deny; Jaffri, Juliana Md

    2017-04-05

    The development of hydrogel films as wound healing dressings is of a great interest owing to their biological tissue-like nature. Polyvinyl alcohol/polyethylene glycol (PVA/PEG) hydrogels loaded with asiaticoside, a standardized rich fraction of Centella asiatica, were successfully developed using the freeze-thaw method. Response surface methodology with Box-Behnken experimental design was employed to optimize the hydrogels. The hydrogels were characterized and optimized by gel fraction, swelling behavior, water vapor transmission rate and mechanical strength. The formulation with 8% PVA, 5% PEG 400 and five consecutive freeze-thaw cycles was selected as the optimized formulation and was further characterized by its drug release, rheological study, morphology, cytotoxicity and microbial studies. The optimized formulation showed more than 90% drug release at 12 hours. The rheological properties exhibited that the formulation has viscoelastic behavior and remains stable upon storage. Cell culture studies confirmed the biocompatible nature of the optimized hydrogel formulation. In the microbial limit tests, the optimized hydrogel showed no microbial growth. The developed optimized PVA/PEG hydrogel using freeze-thaw method was swellable, elastic, safe, and it can be considered as a promising new wound dressing formulation.

  19. Stereocomplex mediated gelation of PEG-(PLA)2 and PEG(PLA)8 block copolymers

    NARCIS (Netherlands)

    Hiemstra, C.; Zhong, Zhiyuan; Dijkstra, Pieter J.; Feijen, Jan

    2005-01-01

    Stereocomplex mediated hydrogels have been prepared by mixing solutions of polymers of opposite chirality of either PEG-(PLA)2 triblock copolymers or PEG-(PLA)8 star block copolymers. The critical gel concentrations of the mixed enantiomer solutions were considerably lower compared to polymer

  20. Synthesis and characterization of injectable, thermosensitive, and biocompatible acellular bone matrix/poly(ethylene glycol)-poly (ε-caprolactone)-poly(ethylene glycol) hydrogel composite.

    Science.gov (United States)

    Ni, Pei-Yan; Fan, Min; Qian, Zhi-Yong; Luo, Jing-Cong; Gong, Chang-Yang; Fu, Shao-Zhi; Shi, Shuai; Luo, Feng; Yang, Zhi-Ming

    2012-01-01

    In orthopedic tissue engineering, the extensively applied acellular bone matrix (ABM) can seldom be prefabricated just right to mold the cavity of the diverse defects, might induce severe inflammation on account of the migration of small granules and usually bring the patients great pain in the treatment. In this study, a new injectable thermosensitive ABM/PECE composite with good biocompatibility was designed and prepared by adding the ABM granules into the triblock copolymer poly(ethylene eglycol)-poly(ε-caprolactone)-poly(ethylene eglycol) (PEG-PCL-PEG, PECE). The PECE was synthesized by ring-opening copolymerization and characterized by ¹H NMR. The ABM was prepared by acellular treatment of natural bone and ground to fine granules. The obtained ABM/PECE composite showed the most important absorption bands of ABM and PECE copolymer in FT-IR spectroscopy and underwent sol-gel phage transition from solution to nonflowing hydrogel at 37°C. SEM results indicated that the ABM/PECE composite with different ABM contents all presented similar porous 3D structure. ABM/PECE composite presented mild cytotoxicity to rat MSCs in vitro and good biocompatibility in the BALB/c mice subcutis up to 4 weeks. In conclusion, all the results confirmed that the injectable thermosensitive ABM/PECE composite was a promising candidate for orthopedic tissue engineering in a minimally-invasive way. Copyright © 2011 Wiley Periodicals, Inc.

  1. Nondestructive evaluation of a new hydrolytically degradable and photo-clickable PEG hydrogel for cartilage tissue engineering.

    Science.gov (United States)

    Neumann, Alexander J; Quinn, Timothy; Bryant, Stephanie J

    2016-07-15

    Photopolymerizable and hydrolytically labile poly(ethylene glycol) (PEG) hydrogels formed from photo-clickable reactions were investigated as cell delivery platforms for cartilage tissue engineering (TE). PEG hydrogels were formed from thiol-norbornene PEG macromers whereby the crosslinks contained caprolactone segments with hydrolytically labile ester linkages. Juvenile bovine chondrocytes encapsulated in the hydrogels were cultured for up to four weeks and assessed biochemically and histologically, using standard destructive assays, and for mechanical and ultrasound properties, as nondestructive assays. Bulk degradation of acellular hydrogels was confirmed by a decrease in compressive modulus and an increase in mass swelling ratio over time. Chondrocytes deposited increasing amounts of sulfated glycosaminoglycans and collagens in the hydrogels with time. Spatially, collagen type II and aggrecan were present in the neotissue with formation of a territorial matrix beginning at day 21. Nondestructive measurements revealed an 8-fold increase in compressive modulus from days 7 to 28, which correlated with total collagen content. Ultrasound measurements revealed changes in the constructs over time, which differed from the mechanical properties, and appeared to correlate with ECM structure and organization shown by immunohistochemical analysis. Overall, non-destructive and destructive measurements show that this new hydrolytically degradable PEG hydrogel is promising for cartilage TE. Designing synthetic hydrogels whose degradation matches tissue growth is critical to maintaining mechanical integrity as the hydrogel degrades and new tissue forms, but is challenging due to the nature of the hydrogel crosslinks that inhibit diffusion of tissue matrix molecules. This study details a promising, new, photo-clickable and synthetic hydrogel whose degradation supports cartilaginous tissue matrix growth leading to the formation of a territorial matrix, concomitant with an

  2. In vivo biocompatibility of p(HPMAm-lac)-PEG hydrogels hybridized with hyaluronan

    NARCIS (Netherlands)

    Sabbieti, Maria Giovanna; Dubbini, Alessandra; Laus, Fulvio; Paggi, Emanuele; Marchegiani, Andrea; Capitani, Melania; Marchetti, Luigi; Dini, Fabrizio; Vermonden, Tina; Di Martino, Piera; Agas, Dimitrios; Censi, Roberta

    2017-01-01

    The present study reports on the biocompatibility in vivo after intramuscular and subcutaneous administration in Balb/c mice of vinyl sulphone bearing p(HPMAm-lac1-2)-PEG-p(HPMAm-lac1-2)/thiolated hyaluronic acid hydrogels, designed as novel injectable biomaterials for potential application in the

  3. Tailoring Properties of Biocompatible PEG-DMA Hydrogels with UV Light

    DEFF Research Database (Denmark)

    Bäckström, Sania; Benavente, Juana; Berg, Rolf W.

    2012-01-01

    and stabilization of painted biomimetic membrane arrays for novel separation technologies or biosensor applications. These gels were formed from PEG-DMA monomers suspended in phosphate buffered saline (PBS) solution and gelated by radical polymerization in the presence of the photoinitiator Darocur 1173....... In this work, we show that the properties of a PEG-DMA hydrogel formed by photoinitiated polymerize- tion can be tailored by varying the photocrosslinking time. Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy (RS) showed that the optimal crosslinking time for the gel was 6 - 10 minutes...... and that the water content of the gels could be tuned in the range of 50 - 90 wt%. The resistivity was between 0.8 - 3.5 Ωm, which is comparable to that of PBS. The low resistivity of the gel makes it compatible for encapsulating membranes for (ion channel based) biosensor applications. With FTIR and RS we...

  4. Synthesis and characterization of biodegradable poly (ethylene glycol) and poly (caprolactone diol) end capped poly (propylene fumarate) cross linked amphiphilic hydrogel as tissue engineering scaffold material.

    Science.gov (United States)

    Krishna, Lekshmi; Jayabalan, Muthu

    2009-12-01

    Biodegradable poly (caprolactone diol-co-propylene fumarate-co-ethylene glycol) amphiphilic polymer with poly (ethylene glycol) and poly (caprolactone diol) chain ends (PCL-PPF-PEG) was prepared. PCL-PPF-PEG undergoes fast setting with acrylamide (aqueous solution) by free radical polymerization and produces a crosslinked hydrogel. The cross linked and freeze-dried amphiphilic material has porous and interconnected network. It undergoes higher degree of swelling and water absorption to form hydrogel with hydrophilic and hydrophobic domains at the surface and appreciable tensile strength. The present hydrogel is compatible with L929 fibroblast cells. PCL-PPF-PEG/acrylamide hydrogel is a candidate scaffold material for tissue engineering applications.

  5. Kinetic and theoretical studies of novel biodegradable thermo-sensitive xerogels based on PEG/PVP/silica for sustained release of enrofloxacin

    Science.gov (United States)

    Ebadi, Azra; Rafati, Amir Abbas; Bavafa, Sadeghali; Mohammadi, Masoumah

    2017-12-01

    This study involves the synthesis of a new silica-based colloidal hybrid system. In this new hybrid system, poly (ethylene glycol) (PEG) and thermo-sensitive amphiphilic biocompatible poly (vinyl pyrrolidone) (PVP) were used to create suitable storage for hydrophobic drugs. The possibility of using variable PVP/PEG molar ratios to modulate drug release rate from silica nanoparticles was a primary goal of the current research. In addition, an investigation of the drug release kinetic was conducted. To achieve this, silica nanoparticles were synthesized in poly (ethylene glycol) (PEG) and poly (vinyl pyrrolidone) (PVP) solution incorporated with enrofloxacin (EFX) (as a model hydrophobic drug), using a simple synthetic strategy of hybrid materials which avoided waste and multi-step processes. The impacts of PVP/PEG molar ratios, temperature, and pH of the release medium on release kinetic were investigated. The physicochemical properties of the drug-loaded composites were studied by Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). In vitro drug release studies demonstrated that the drug release rate, which was evaluated by analyzing the experimental data with seven kinetic models in a primarily non-Fickian diffusion-controlled process, aligned well with both Ritger-Peppas and Sahlin-Peppas equations.

  6. Novel Injectable Pentablock Copolymer Based Thermoresponsive Hydrogels for Sustained Release Vaccines.

    Science.gov (United States)

    Bobbala, Sharan; Tamboli, Viral; McDowell, Arlene; Mitra, Ashim K; Hook, Sarah

    2016-01-01

    The need for multiple vaccinations to enhance the immunogenicity of subunit vaccines may be reduced by delivering the vaccine over an extended period of time. Here, we report two novel injectable pentablock copolymer based thermoresponsive hydrogels made of polyethyleneglycol-polycaprolactone-polylactide-polycaprolactone-polyethyleneglycol (PEG-PCL-PLA-PCL-PEG) with varying ratios of polycaprolactone (PCL) and polylactide (PLA), as single shot sustained release vaccines. Pentablock copolymer hydrogels were loaded with vaccine-encapsulated poly lactic-co-glycolic acid nanoparticles (PLGA-NP) or with the soluble vaccine components. Incorporation of PLGA-NP into the thermoresponsive hydrogels increased the complex viscosity of the gels, lowered the gelation temperature, and minimized the burst release of antigen and adjuvants. The two pentablock hydrogels stimulated both cellular and humoral responses. The addition of PLGA-NP to the hydrogels sustained immune responses for up to 49 days. The polymer with a higher ratio of PCL to PLA formed a more rigid gel, induced stronger immune responses, and stimulated effective anti-tumor responses in a prophylactic melanoma tumor model.

  7. A PLGA-PEG-PLGA Thermosensitive Gel Enabling Sustained Delivery of Ropivacaine Hydrochloride for Postoperative Pain Relief.

    Science.gov (United States)

    Fu, Xudong; Zeng, Huilin; Guo, Jiaping; Liu, Hong; Shi, Zhen; Chen, Huhai; Li, Dezong; Xie, Xiangyang; Kuang, Changchun

    2017-01-01

    Postoperative pain is a complex physiological response to disease and tissue injury. Moderate-to-severe pain typically occurs within 48 h after surgery. Amino amide local anesthetics are widely applied to manage postoperative pain, and they have high efficacy, a low risk for addiction and limited side effects. However, these anesthetics also have short half-lives, often necessitating continuous injection to obtain satisfactory pain relief. In the current work, we used a poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA (PLGA-PEG-PLGA) temperature-sensitive gel to deliver a local anesthetic, ropivacaine hydrochloride (RP), to prolong its analgesic effect. We investigated the influence of polymer and drug concentration on gelation temperature and the in vitro drug release rate from the temperature-sensitive gel. RP-loaded PLGA-PEG-PLGA solution is a liquid at room temperature and forms a gel at temperatures slightly lower than body temperature. With regard to the gel's drug release rate, 37.5, 51.3 and 72.6% of RP was released at 12, 24 and 48 h, respectively. This in vitro drug release profile conformed to the Higuchi equation. To assess pain control efficacy when using the gel, we evaluated the mechanical paw withdrawal reflex threshold, thermal pain threshold and incision cumulative pain scores in a rat incisional model. The results showed that the anti-pain effect of a single injection of RP-loaded gel at the incision site lasted for 48 h, which is significantly longer than the effect produced by injection of RP solution alone. The use of RP-loaded thermosensitive gels could provide a promising method for managing postoperative pain.

  8. PEG and mPEG-anthracene induce DNA condensation and particle formation.

    Science.gov (United States)

    Froehlich, E; Mandeville, J S; Arnold, D; Kreplak, L; Tajmir-Riahi, H A

    2011-08-18

    In this study, we investigated the binding of DNA with poly(ethylene glycol) (PEG) of different sizes and compositions such as PEG 3350, PEG 6000, and mPEG-anthracene in aqueous solution at physiological conditions. The effects of size and composition on DNA aggregation and condensation as well as conformation were determined using Fourier transform infrared (FTIR), UV-visible, CD, fluorescence spectroscopic methods and atomic force microscopy (AFM). Structural analysis showed moderate complex formation for PEG 3350 and PEG 6000 and weaker interaction for mPE-anthracene-DNA adducts with both hydrophilic and hydrophobic contacts. The order of ± stability of the complexes formed is K(PEG 6000) = 1.5 (±0.4) × 10(4) M(-1) > K(PEG 3350) = 7.9 (±1) × 10(3) M(-1) > K(m(PEG-anthracene))= 3.6 (±0.8) × 10(3) M(-1) with nearly 1 bound PEG molecule per DNA. No B-DNA conformational changes were observed, while DNA condensation and particle formation occurred at high PEG concentration.

  9. Hyaluronic Acid (HA)-Polyethylene glycol (PEG) as injectable hydrogel for intervertebral disc degeneration patients therapy

    Science.gov (United States)

    Putri Kwarta, Cityta; Widiyanti, Prihartini; Siswanto

    2017-05-01

    Chronic Low Back Pain (CLBP) is one health problem that is often encountered in a community. Inject-able hydrogels are the newest way to restore the disc thickness and hydration caused by disc degeneration by means of minimally invasive surgery. Thus, polymers can be combined to improve the characteristic properties of inject-able hydrogels, leading to use of Hyaluronic Acid (a natural polymer) and Polyethylene glycol (PEG) with Horse Radish Peroxide (HRP) cross linker enzymes. The swelling test results, which approaches were the ideal disc values, were sampled with variation of enzyme concentrations of 0.25 µmol/min/mL. The enzyme concentrations were 33.95%. The degradation test proved that the sample degradation increased along with the decrease of the HRP enzyme concentration. The results of the cytotoxicity assay with MTT assay method showed that all samples resulted in the 90% of living cells are not toxic. In vitro injection, models demonstrated that higher concentration of the enzymes was less state of gel which would rupture when released from the agarose gel. The functional group characterization shows the cross linking bonding in sample with enzyme adding. The conclusion of this study is PEG-HA-HRP enzyme are safe polymer composites which have a potential to be applied as an injectable hydrogel for intervertebral disc degeneration.

  10. Solid-state NMR study of stereocomplexes formed by enantiomeric star-shaped PEG-PLA copolymers in water

    NARCIS (Netherlands)

    Calucci, Lucia; Forte, Claudia; Buwalda, S.J.; Dijkstra, Pieter J.

    2011-01-01

    Solid-state NMR was applied to samples obtained by freeze-drying hydrogels of 1:1 (PEG65-NHCO-PLLA13)8/(PEG65-NHCO-PDLA13)8 or (PEG65-NHCO-PDLA13)8 only star block copolymers (where PEG, PLLA, and PDLA stand for poly(ethylene glycol), poly(l-lactide), and poly(d-lactide), respectively) in order to

  11. Experiment and model for the viscosities of MEA-PEG400, DEA-PEG400 and MDEA-PEG400 aqueous solutions

    International Nuclear Information System (INIS)

    Fu, Dong; Zhang, Pan; Du, LeiXia; Dai, Jing

    2014-01-01

    Highlights: • The viscosities of the amine-PEG400 aqueous solutions were measured. • The experiments were modeled satisfactorily by using the Weiland equation. • The effect of mass fractions of amine and PEG400 on the viscosity was illustrated. • The temperature dependence of the viscosity was demonstrated. - Abstract: The viscosities (η) of poly(ethylene oxide)400 (PEG400), monoethanolamine (MEA)-PEG400, diethanolamine (DEA)-PEG400 and N-methyldiethanolamine (MDEA)-PEG400 aqueous solutions were measured by using the NDJ-5S digital rotational viscometer. A thermodynamic equation was used to model the viscosities and the calculated results are satisfactory. The effects of temperature, mass fractions of amines and PEG400 on the viscosities were demonstrated on the basis of experiments and calculations

  12. Viral infection of human progenitor and liver-derived cells encapsulated in three-dimensional PEG-based hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Nam-Joon; Elazar, Menashe; Xiong, Anming; Glenn, Jeffrey S [Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, CCSR Building Room 3115A, 269 Campus Drive, Stanford, CA 94305 (United States); Lee, Wonjae [Mechanical Engineering, Stanford University, Stanford, CA 94305 (United States); Chiao, Eric; Baker, Julie [Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 (United States); Frank, Curtis W, E-mail: jeffrey.glenn@stanford.ed, E-mail: curt.frank@stanford.ed [Department of Chemical Engineering, Stanford University, Stanford, CA 94305 (United States)

    2009-02-15

    We have studied the encapsulation of human progenitor cells into 3D PEG hydrogels. Replication-incompetent lentivirus promoter reporter vectors were found to efficiently detect the in vivo expression of human hepatic genes in hydrogel-encapsulated liver progenitor cells. Similarly, hydrogel-encapsulated cells could be efficiently infected with hepatitis C virus, and progeny infectious virus could be recovered from the media supernatants of the hydrogels. Provocatively, the diameters of these virus particles range from {approx}50 to 100 nm, while the calculated mesh size of the 8 k hydrogel is 44.6 +- 1.7 A. To reconcile how viral particles can penetrate the hydrogels to infect the encapsulated cells, we propose that microfractures/defects of the hydrogel result in a functional pore size of up to 20 fold greater than predicted by theoretical mesh calculations. These results suggest a new model of hydrogel structure, and have exciting implications for tissue engineering and hepatitis virus studies. (communication)

  13. Viral infection of human progenitor and liver-derived cells encapsulated in three-dimensional PEG-based hydrogel

    International Nuclear Information System (INIS)

    Cho, Nam-Joon; Elazar, Menashe; Xiong, Anming; Glenn, Jeffrey S; Lee, Wonjae; Chiao, Eric; Baker, Julie; Frank, Curtis W

    2009-01-01

    We have studied the encapsulation of human progenitor cells into 3D PEG hydrogels. Replication-incompetent lentivirus promoter reporter vectors were found to efficiently detect the in vivo expression of human hepatic genes in hydrogel-encapsulated liver progenitor cells. Similarly, hydrogel-encapsulated cells could be efficiently infected with hepatitis C virus, and progeny infectious virus could be recovered from the media supernatants of the hydrogels. Provocatively, the diameters of these virus particles range from ∼50 to 100 nm, while the calculated mesh size of the 8 k hydrogel is 44.6 ± 1.7 A. To reconcile how viral particles can penetrate the hydrogels to infect the encapsulated cells, we propose that microfractures/defects of the hydrogel result in a functional pore size of up to 20 fold greater than predicted by theoretical mesh calculations. These results suggest a new model of hydrogel structure, and have exciting implications for tissue engineering and hepatitis virus studies. (communication)

  14. Effect of PEG and mPEG-anthracene on tRNA aggregation and particle formation.

    Science.gov (United States)

    Froehlich, E; Mandeville, J S; Arnold, D; Kreplak, L; Tajmir-Riahi, H A

    2012-01-09

    Poly(ethylene glycol) (PEG) and its derivatives are synthetic polymers with major applications in gene and drug delivery systems. Synthetic polymers are also used to transport miRNA and siRNA in vitro. We studied the interaction of tRNA with several PEGs of different compositions, such as PEG 3350, PEG 6000, and mPEG-anthracene under physiological conditions. FTIR, UV-visible, CD, and fluorescence spectroscopic methods as well as atomic force microscopy (AFM) were used to analyze the PEG binding mode, the binding constant, and the effects of polymer complexation on tRNA stability, aggregation, and particle formation. Structural analysis showed that PEG-tRNA interaction occurs via RNA bases and the backbone phosphate group with both hydrophilic and hydrophobic contacts. The overall binding constants of K(PEG 3350-tRNA)= 1.9 (±0.5) × 10(4) M(-1), K(PEG 6000-tRNA) = 8.9 (±1) × 10(4) M(-1), and K(mPEG-anthracene)= 1.2 (±0.40) × 10(3) M(-1) show stronger polymer-RNA complexation by PEG 6000 and by PEG 3350 than the mPEG-anthracene. AFM imaging showed that PEG complexes contain on average one tRNA with PEG 3350, five tRNA with PEG 6000, and ten tRNA molecules with mPEG-anthracene. tRNA aggregation and particle formation occurred at high polymer concentrations, whereas it remains in A-family structure.

  15. Characterization and tribology of PEG-like coatings on UHMWPE for total hip replacements.

    Science.gov (United States)

    Kane, Sheryl R; Ashby, Paul D; Pruitt, Lisa A

    2010-03-15

    A crosslinked hydrogel coating similar to poly(ethylene glycol) (PEG) was covalently bonded to the surface of ultrahigh molecular weight polyethylene (UHMWPE) to improve the lubricity and wear resistance of the UHWMPE for use in total joint replacements. The chemistry, hydrophilicity, and protein adsorption resistance of the coatings were determined, and the wear behavior of the PEG-like coating was examined by two methods: pin-on-disk tribometry to evaluate macroscale behavior, and atomic force microscopy (AFM) to simulate asperity wear. As expected, the coating was found to be highly PEG-like, with approximately 83% ether content by x-ray photoelectron spectroscopy and more hydrophilic and resistant to protein adsorption than uncoated UHMWPE. Pin-on-disk testing showed that the PEG-like coating could survive 3 MPa of contact pressure, comparable to that experienced by total hip replacements. AFM nanoscratching experiments uncovered three damage mechanisms for the coatings: adhesion/microfracture, pure adhesion, and delamination. The latter two mechanisms appear to correlate well with wear patterns induced by pin-on-disk testing and evaluated by attenuated total reflection Fourier transform infrared spectroscopy mapping. Understanding the mechanisms by which the PEG-like coatings wear is critical for improving the behavior of subsequent generations of wear-resistant hydrogel coatings. (c) 2009 Wiley Periodicals, Inc.

  16. Biodegradation of polyethylene glycol (PEG) in three tropical soils using radio labelled PEG

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, A.L. [Laboratory of Animal Nutrition, Centre for Nuclear Energy in Agriculture, University of Sao Paulo (CENA/USP), Piracicaba SP (Brazil)]. E-mail: abdalla@cena.usp.br; Regitano, J.B.; Tornisielo, V.L.; Marchese, L. [Laboratory of Ecotoxicology, Piracicaba SP (Brazil); Pecanha, M.R.S.R.; Vitti, D.M.S.S. [Laboratory of Animal Nutrition, Centre for Nuclear Energy in Agriculture, University of Sao Paulo (CENA/USP), Piracicaba SP (Brazil); Smith, T. [School of Agriculture, Policy and Development, University of Reading, Reading (United Kingdom)

    2005-08-19

    Polyethylene glycol (PEG) may be added to forage based diets rich in tannins for ruminant feeding because it binds to tannins and thus prevent the formation of potentially indigestible tannin-protein complexes. The objective of this work was to determine the in vitro biodegradation (mineralization, i.e., complete breakdown of PEG to CO{sub 2}) rate of PEG. {sup 14}C-Polyethylene glycol ({sup 14}C-PEG) was added to three different tropical soils (a sandy clay loam soil, SaCL; a sandy clay soil, SaC; and a sandy loam soil, SaL) and was incubated in Bartha flasks. Free PEG and PEG bound to tannins from a tannin rich local shrub were incubated under aerobic conditions for up to 70 days. The biodegradation assay monitored the {sup 14}CO{sub 2} evolved after degradation of the labelled PEG in the soils. After incubation, the amount of {sup 14}CO{sub 2} evolved from the {sup 14}C-PEG application was low. Higher PEG mineralization values were found for the soils with higher organic matter contents (20.1 and 18.6 g organic matter/kg for SaCL and SaC, respectively) than for the SaL soil (11.9 g organic matter/kg) (P < 0.05). The extent of mineralization of PEG after 70 days of incubation in the soil was significantly lower (P < 0.05) when it was added as bound to the browse tannin than in the free form (0.040 and 0.079, respectively). (author)

  17. PEG Tube Placement

    Directory of Open Access Journals (Sweden)

    Saptarshi Biswas

    2014-01-01

    Full Text Available Percutaneous endoscopic gastrostomy (PEG has been used for providing enteral access to patients who require long-term enteral nutrition for years. Although generally considered safe, PEG tube placement can be associated with many immediate and delayed complications. Buried bumper syndrome (BBS is one of the uncommon and late complications of percutaneous endoscopic gastrostomy (PEG placement. It occurs when the internal bumper of the PEG tube erodes into the gastric wall and lodges itself between the gastric wall and skin. This can lead to a variety of additional complications such as wound infection, peritonitis, and necrotizing fasciitis. We present here a case of buried bumper syndrome which caused extensive necrosis of the anterior abdominal wall.

  18. PEG-asparaginase induced severe hypertriglyceridemia.

    Science.gov (United States)

    Galindo, Rodolfo J; Yoon, Justin; Devoe, Craig; Myers, Alyson K

    2016-04-01

    Asparaginase (ASP) is an effective chemotherapy agent extensively used in children with acute lymphocytic leukemia (ALL). There has been a recent interest in using ASP in adults with ALL, particularly the less toxic pegylated (PEG) formulation. Hypertriglyceridemia (HTG) is a rare complication of PEG-ASP therapy. We report two cases of obese patients who developed severe HTG after receiving PEG for ALL. Both patients were incidentally found to have severe HTG (TG of 4,330 and 4,420 mg/dL). In both patients, there was no personal or family history of dyslipidemia or hypothyroidism. There was no evidence of pancreatitis or skin manifestations of HTG. Both patients were treated with PEG cessation, low-fat diet and pharmacotherapy. Both patients were re-challenged with PEG, with subsequent increase in TG but no associated complications. TG returned to baseline after discontinuing PEG and while on therapy for HTG. A literature review of PEG-induced HTG in adults demonstrated similar results: asymptomatic presentation despite very severe HTG. HTG is a rare but clinically important adverse effect of PEG. Underlying obesity and/or diabetes may represent risk factors. Clinicians should monitor TG levels during PEG therapy to avoid TG-induced pancreatitis.

  19. Thiol-Ene Photo-Click Collagen-PEG Hydrogels: Impact of Water-Soluble Photoinitiators on Cell Viability, Gelation Kinetics and Rheological Properties

    Directory of Open Access Journals (Sweden)

    Róisín Holmes

    2017-06-01

    Full Text Available Thiol-ene photo-click hydrogels were prepared via step-growth polymerisation using thiol-functionalised type-I collagen and 8-arm poly(ethylene glycol norbornene-terminated (PEG-NB, as a potential injectable regenerative device. Type-I collagen was thiol-functionalised by a ring opening reaction with 2-iminothiolane (2IT, whereby up to 80 Abs.% functionalisation and 90 RPN% triple helical preservation were recorded via 2,4,6-Trinitrobenzenesulfonic acid (TNBS colorimetric assay and circular dichroism (CD. Type, i.e., either 2-Hydroxy-1-[4-(2-hydroxyethoxy phenyl]-2-methyl-1-propanone (I2959 or lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP, and concentration of photoinitiator were varied to ensure minimal photoinitiator-induced cytotoxicity and to enable thiol-ene network formation of collagen-PEG mixtures. The viability of G292 cells following 24 h culture in photoinitiator-supplemented media was largely affected by the photoinitiator concentration, with I2959-supplemented media observed to induce higher toxic response (0.1 → 0.5% (w/v I2959, cell survival: 62 → 2 Abs.% compared to LAP-supplemented media (cell survival: 86 → 8 Abs.%. In line with the in vitro study, selected photoinitiator concentrations were used to prepare thiol-ene photo-click hydrogels. Gelation kinetics proved to be largely affected by the specific photoinitiator, with LAP-containing thiol-ene mixtures leading to significantly reduced complete gelation time (τ: 187 s with respect to I2959-containing mixtures (τ: 1683 s. Other than the specific photoinitiator, the photoinitiator concentration was key to adjusting the hydrogel storage modulus (G’, whereby 15-fold G’ increase (232 → 3360 Pa was observed in samples prepared with 0.5% (w/v compared to 0.1% (w/v LAP. Further thiol-ene formulations with 0.5% (w/v LAP and varied content of PEG-NB were tested to prepare photo-click hydrogels with porous architecture, as well as tunable storage modulus (G

  20. Nanoporous capsules of block co-polymers of [(MeO-PEG-NH)-b-(L-GluA)]-PCL for the controlled release of anticancer drugs for therapeutic applications

    Science.gov (United States)

    Amgoth, Chander; Dharmapuri, Gangappa; Kalle, Arunasree M.; Paik, Pradip

    2016-03-01

    Herein, new nanoporous capsules of the block co-polymers of MeO-PEG-NH-(L-GluA)10 and polycaprolactone (PCL) have been synthesized through a surfactant-free cost-effective self-assembled soft-templating approach for the controlled release of drugs and for therapeutic applications. The nanoporous polymer capsules are designed to be biocompatible and are capable of encapsulating anticancer drugs (e.g., doxorubicin hydrochloride (DOX) and imatinib mesylate (ITM)) with a high extent (˜279 and ˜480 ng μg-1, respectively). We have developed a nanoformulation of porous MeO-PEG-NH-(L-GluA)10-PCL capsules with DOX and ITM. The porous polymer nanoformulations have been programmed in terms of the release of anticancer drugs with a desired dose to treat the leukemia (K562) and human carcinoma cells (HepG2) in vitro and show promising IC50 values with a very high mortality of cancer cells (up to ˜96.6%). Our nanoformulation arrests the cell divisions due to ‘cellular scenescence’ and kills the cancer cells specifically. The present findings could enrich the effectiveness of idiosyncratic nanoporous polymer capsules for use in various other nanomedicinal and biomedical applications, such as for killing cancer cells, immune therapy, and gene delivery.

  1. Nanoporous capsules of block co-polymers of [(MeO-PEG-NH)-b-(L-GluA)]-PCL for the controlled release of anticancer drugs for therapeutic applications

    International Nuclear Information System (INIS)

    Amgoth, Chander; Paik, Pradip; Dharmapuri, Gangappa; Kalle, Arunasree M

    2016-01-01

    Herein, new nanoporous capsules of the block co-polymers of MeO-PEG-NH-(L-GluA) 10 and polycaprolactone (PCL) have been synthesized through a surfactant-free cost-effective self-assembled soft-templating approach for the controlled release of drugs and for therapeutic applications. The nanoporous polymer capsules are designed to be biocompatible and are capable of encapsulating anticancer drugs (e.g., doxorubicin hydrochloride (DOX) and imatinib mesylate (ITM)) with a high extent (∼279 and ∼480 ng μg −1 , respectively). We have developed a nanoformulation of porous MeO-PEG-NH-(L-GluA) 10 -PCL capsules with DOX and ITM. The porous polymer nanoformulations have been programmed in terms of the release of anticancer drugs with a desired dose to treat the leukemia (K562) and human carcinoma cells (HepG2) in vitro and show promising IC 50 values with a very high mortality of cancer cells (up to ∼96.6%). Our nanoformulation arrests the cell divisions due to ‘cellular scenescence’ and kills the cancer cells specifically. The present findings could enrich the effectiveness of idiosyncratic nanoporous polymer capsules for use in various other nanomedicinal and biomedical applications, such as for killing cancer cells, immune therapy, and gene delivery. (paper)

  2. The synthesis of hydrogels with controlled distribution of polymer brushes in hydrogel network

    Energy Technology Data Exchange (ETDEWEB)

    Sun, YuWei; Zhou, Chao; Zhang, AoKai; Xu, LiQun; Yao, Fang [School of Chemistry and Chemical Engineering, Southeast University, Jiangning District, Nanjing, Jiangsu Province, 211189 (China); Cen, Lian, E-mail: cenlian@hotmail.com [National Tissue Engineering Center of China, No.68, East Jiang Chuan Road, Shanghai, 200241 (China); School of Chemical Engineering, East China University of Science and Technology, No.130, Mei Long Road, Shanghai, 200237 (China); Fu, Guo-Dong, E-mail: fu7352@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Jiangning District, Nanjing, Jiangsu Province, 211189 (China)

    2014-11-30

    Highlights: • Many biological tissues are 3-dimensionally asymmetric in structure and properties, it would be desirable if hydrogels could bear such structural similarity with specialized surface and bulk properties. Moreover, gradual but continuous variation in spatial structural and property is also a common phenomenon in biological tissues, such as interfaces between bone and tendon, or between bone and cartilage. Hence, the development of a method to introduce well-defined functional polymer brushes on PEG hydrogels, especially with precisely controlled spatial structure in 3-dimensions, would impart the hydrogels with special functionalities and wider applications. Poly(ethylene glycol) (PEG) hydrogels with 3-dimensionally controlled well-defined poly(N-isopropylacrylamide) (poly(NIPAAm)) brushes were prepared by combined copper(I)-catalyzed azide-alkyne cycloaddition (“Click Chemistry”) and atom transfer radical polymerization (ATRP). The resulting hydrogels were presented as representatives with their detailed synthesis routes and characterization. H{sub PEG}-S-poly(NIPAAm) is a hydrogel with poly(NIPAAm) brushes mainly grafted on surface, whereas H{sub PEG}-G-poly(NIPAAm) has a gradiently decreased poly(NIPAAm) brushes in their chain length from surface to inside. On the other hand, poly(NIPAAm) brushes in H{sub PEG}-U-poly(NIPAAm) are uniformly dispersed throughout the whole hydrogel network. Successful preparation of H{sub PEG}-S-poly(NIPAAm), H{sub PEG}-G-poly(NIPAAm) and H{sub PEG}-U-poly(NIPAAm) were ascertained by X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. Hence, the flexibility and controllability of the synthetic strategy in varying the distribution of polymer brushes and hydrogel surface properties was demonstrated. Hydrogels with tunable and well-defined 3-dimensional poly(NIPAAm) polymer brushes could be tailor-designed to find potential applications in smart devices or skin dressing, such as for diabetics

  3. Evaluation of a novel biodegradable thermosensitive keto-hydrogel for improving postoperative pain in a rat model.

    Science.gov (United States)

    Wu, Meng-Huang; Shih, Ming-Hung; Hsu, Wei-Bin; Dubey, Navneet Kumar; Lee, Wen-Fu; Lin, Tsai-Yu; Hsieh, Meng-Yow; Chen, Chin-Fu; Peng, Kuo-Ti; Huang, Tsung-Jen; Shi, Chung-Sheng; Guo, Ren-Shyang; Cai, Chang-Jhih; Chung, Chiu-Yen; Wong, Chung-Hang

    2017-01-01

    This study evaluates the sustained analgesic effect of ketorolac-eluting thermosensitive biodegradable hydrogel in the plantar incisional pain model of the rat hind-paw. A ketorolac-embedded 2, 2'-Bis (2-oxazolin) (BOX) linking methoxy-poly(ethylene glycol) and poly(lactide-co-glycolide) (mPEG-PLGA) diblock copolymer (BOX copolymer) was synthesized as keto-hydrogel based on optimal sol-gel phase transition and in vitro drug release profile. The effect of keto-hydrogel on postoperative pain (POP) was assessed using the established plantar incisional pain model in hind-paw of rats and compared to that of ketorolac solution. Pain and sensory threshold, as well as pain scoring, were evaluated with behavioral tests by means of anesthesiometer and incapacitance apparatus, respectively. Pro-inflammatory cytokine levels (TNF-α, IL-6, VEGF, and IL-1β) around incisional wounds were measured by ELISA. Tissue histology was assessed using hematoxylin and eosin and Masson's trichrome staining. Ten mg/mL (25 wt%) keto-hydrogel showed a sol-gel transition at 26.4°C with a 10-day sustained drug release profile in vitro. Compared to ketorolac solution group, the concentration of ketorolac in tissue fluid was higher in the keto-hydrogel group during the first 18 h of application. Keto-hydrogel elevated pain and sensory threshold, increased weight-bearing capacity, and significantly reduced the levels of TNF-α, IL-6, and IL-1β while enhanced VEGF in tissue fluid. Histologic analysis reveals greater epithelialization and collagen deposition around wound treated with keto-hydrogel. In conclusion, our study suggests that keto-hydrogel is an ideal compound to treat POP with a secondary gain of improved incisional wound healing.

  4. Evaluation of a novel biodegradable thermosensitive keto-hydrogel for improving postoperative pain in a rat model.

    Directory of Open Access Journals (Sweden)

    Meng-Huang Wu

    Full Text Available This study evaluates the sustained analgesic effect of ketorolac-eluting thermosensitive biodegradable hydrogel in the plantar incisional pain model of the rat hind-paw. A ketorolac-embedded 2, 2'-Bis (2-oxazolin (BOX linking methoxy-poly(ethylene glycol and poly(lactide-co-glycolide (mPEG-PLGA diblock copolymer (BOX copolymer was synthesized as keto-hydrogel based on optimal sol-gel phase transition and in vitro drug release profile. The effect of keto-hydrogel on postoperative pain (POP was assessed using the established plantar incisional pain model in hind-paw of rats and compared to that of ketorolac solution. Pain and sensory threshold, as well as pain scoring, were evaluated with behavioral tests by means of anesthesiometer and incapacitance apparatus, respectively. Pro-inflammatory cytokine levels (TNF-α, IL-6, VEGF, and IL-1β around incisional wounds were measured by ELISA. Tissue histology was assessed using hematoxylin and eosin and Masson's trichrome staining. Ten mg/mL (25 wt% keto-hydrogel showed a sol-gel transition at 26.4°C with a 10-day sustained drug release profile in vitro. Compared to ketorolac solution group, the concentration of ketorolac in tissue fluid was higher in the keto-hydrogel group during the first 18 h of application. Keto-hydrogel elevated pain and sensory threshold, increased weight-bearing capacity, and significantly reduced the levels of TNF-α, IL-6, and IL-1β while enhanced VEGF in tissue fluid. Histologic analysis reveals greater epithelialization and collagen deposition around wound treated with keto-hydrogel. In conclusion, our study suggests that keto-hydrogel is an ideal compound to treat POP with a secondary gain of improved incisional wound healing.

  5. Polyethylene glycols (PEG) and related structures

    DEFF Research Database (Denmark)

    Wenande, Emily; Kroigaard, Mogens; Mosbech, Holger

    2015-01-01

    We describe hypersensitivity to polyethylene glycols (PEGs), with cross-reactivity to a structural analog, polysorbate 80, in a 69-year-old patient with perioperative anaphylaxis and subsequent, severe anaphylactic reactions to unrelated medical products. PEGs and PEG analogs are prevalent in the...

  6. Synthesis and bioactivity study of 30kda linear peg-interferon and its comparison with tri-branched peg-interferon

    International Nuclear Information System (INIS)

    Sabar, M.F.; Awan, F.I.

    2013-01-01

    Summary: Polyethylene glycol (PEG) is conjugated to the therapeutic proteins to enhance their circulating half life. PEGylation is a clinically proven strategy for increasing the therapeutic efficacy of protein-based medicines. PEG size and structure is very important in achieving specific properties in the conjugated protein. In this study we have compared the properties of newly synthesized linear PEG-IFN with a same sized (i.e., 30KDa) tri-branched PEG-IFN synthesized in the same lab earlier. For PEGylation reaction, interferon-alpha2 (IFNalpha2) concentration in sodium borate buffer pH 8.5 was optimized as 4.0mg/ml. The optimized molar ratio of PEG/IFN alpha2 was 3:1 instead of 5:1 in the case of tri-branched PEG published earlier. Other parameters of reaction were same as in our previous publication. Mono PEGylation degree reached to 21%. Cation exchange chromatography was used to separate and purify mono PEGylated IFN from the reaction mixture. The purity of mono PEGylated IFN was greater than 95%. It is noticed that PEGylation was more site specific in tribranched than the linear conjugate. The in vitro bioactivity of linear mPEG-IFN is 10-fold lesser than as reported of tri-branched mPEG3L2-IFN. Thermal stability of linear mPEG-IFN is also smaller than mPEG/sub 3/L/sub 2/-IFN at 4 degree C. (author)

  7. Novel thermosensitive telechelic PEGs with antioxidant activity: synthesis, molecular properties and conformational behaviour

    Czech Academy of Sciences Publication Activity Database

    Sergeeva, O.; Vlasov, P. S.; Domnina, N. S.; Bogomolova, Anna; Konarev, P. V.; Svergun, D. I.; Walterová, Zuzana; Horský, Jiří; Štěpánek, Petr; Filippov, Sergey K.

    2014-01-01

    Roč. 4, č. 79 (2014), s. 41763-41771 ISSN 2046-2069 R&D Projects: GA ČR GAP208/10/1600 Institutional support: RVO:61389013 Keywords : PEG * antioxidant * SANS Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.840, year: 2014

  8. Enhanced EGFP Fluorescence Emission in Presence of PEG Aqueous Solutions and PIB1000-PEG6000-PIB1000 Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Noor Muhammad

    2013-01-01

    Full Text Available An EGFP construct interacting with the PIB1000-PEG6000-PIB1000 vesicles surface reported a ~2-fold fluorescence emission enhancement. Because of the constructs nature with the amphiphilic peptide inserted into the PIB core, EGFP is expected to experience a “pure” PEG environment. To unravel this phenomenon PEG/water solutions at different molecular weights and concentrations were used. Already at ~1 : 10 protein/PEG molar ratio the increase in fluorescence emission is observed reaching a plateau correlating with the PEG molecular weight. Parallel experiments in presence of glycerol aqueous solutions did show a slight fluorescence enhancement however starting at much higher concentrations. Molecular dynamics simulations of EGFP in neat water, glycerol, and PEG aqueous solutions were performed showing that PEG molecules tend to “wrap” the protein creating a microenvironment where the local PEG concentration is higher compared to its bulk concentration. Because the fluorescent emission can be perturbed by the refractive index surrounding the protein, the clustering of PEG molecules induces an enhanced fluorescence emission already at extremely low concentrations. These findings can be important when related to the use of EGFP as reported in molecular biology experiments.

  9. Characteristics and cytotoxicity of folate-modified curcumin-loaded PLA-PEG micellar nano systems with various PLA:PEG ratios.

    Science.gov (United States)

    Phan, Quoc Thong; Le, Mai Huong; Le, Thi Thu Huong; Tran, Thi Hong Ha; Xuan, Phuc Nguyen; Ha, Phuong Thu

    2016-06-30

    Targeting delivery system use natural drugs for tumor cells is an appealing platform help to reduce the side effects and enhance the therapeutic effects of the drug. In this study, we synthesized curcumin (Cur) loaded (D, L Poly lactic - Poly ethylenglycol) micelle (Cur/PLA-PEG) with the ratio of PLA/PEG of 3:1 2:1 1:1 1:2 and 1:3 (w/w) and another micelle modified by folate (Cur/PLA-PEG-Fol) for targeting cancer therapy. The PLA-PEG copolymer was synthesized by ring opening polymerization method. After loading onto the micelle, solubility of Cur increased from 0.38 to 0.73mgml(-1). The average size of prepared Cur/PLA-PEG micelles was from 60 to 69nm (corresponding to the ratio difference of PLA/PEG) and the drug encapsulating efficiency was from 48.8 to 91.3%. Compared with the Cur/PLA-PEG micelles, the size of Cur/PLA-PEG-Fol micelles were from 80 to 86nm and showed better in vitro cellular uptake and cytotoxicity towards HepG2 cells. The cytotoxicity of the NPs however depends much on the PEG component. The results demonstrated that Folate-modified micelles could serve as a potential nano carrier to improve solubility, anti-cancer activity of Cur and targeting ability of the system. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Modulation of Huh7.5 spheroid formation and functionality using modified PEG-based hydrogels of different stiffness.

    Directory of Open Access Journals (Sweden)

    Bae Hoon Lee

    Full Text Available Physical cues, such as cell microenvironment stiffness, are known to be important factors in modulating cellular behaviors such as differentiation, viability, and proliferation. Apart from being able to trigger these effects, mechanical stiffness tuning is a very convenient approach that could be implemented readily into smart scaffold designs. In this study, fibrinogen-modified poly(ethylene glycol-diacrylate (PEG-DA based hydrogels with tunable mechanical properties were synthesized and applied to control the spheroid formation and liver-like function of encapsulated Huh7.5 cells in an engineered, three-dimensional liver tissue model. By controlling hydrogel stiffness (0.1-6 kPa as a cue for mechanotransduction representing different stiffness of a normal liver and a diseased cirrhotic liver, spheroids ranging from 50 to 200 μm were formed over a three week time-span. Hydrogels with better compliance (i.e. lower stiffness promoted formation of larger spheroids. The highest rates of cell proliferation, albumin secretion, and CYP450 expression were all observed for spheroids in less stiff hydrogels like a normal liver in a healthy state. We also identified that the hydrogel modification by incorporation of PEGylated-fibrinogen within the hydrogel matrix enhanced cell survival and functionality possibly owing to more binding of autocrine fibronectin. Taken together, our findings establish guidelines to control the formation of Huh7.5 cell spheroids in modified PEGDA based hydrogels. These spheroids may serve as models for applications such as screening of pharmacological drug candidates.

  11. Antibacterial modification of an injectable, biodegradable, non-cytotoxic block copolymer-based physical gel with body temperature-stimulated sol-gel transition and controlled drug release.

    Science.gov (United States)

    Wang, Xiaowen; Hu, Huawen; Wang, Wenyi; Lee, Ka I; Gao, Chang; He, Liang; Wang, Yuanfeng; Lai, Chuilin; Fei, Bin; Xin, John H

    2016-07-01

    Biomaterials are being extensively used in various biomedical fields; however, they are readily infected with microorganisms, thus posing a serious threat to the public health care. We herein presented a facile route to the antibacterial modification of an important A-B-A type biomaterial using poly (ethylene glycol) methyl ether (mPEG)- poly(ε-caprolactone) (PCL)-mPEG as a typical model. Inexpensive, commercial bis(2-hydroxyethyl) methylammonium chloride (DMA) was adopted as an antibacterial unit. The effective synthesis of the antibacterial copolymer mPEG-PCL-∼∼∼-PCL-mPEG (where ∼∼∼ denotes the segment with DMA units) was well confirmed by FTIR and (1)H NMR spectra. At an appropriate modification extent, the DMA unit could render the copolymer mPEG-PCL-∼∼∼-PCL-mPEG highly antibacterial, but did not largely alter its fascinating intrinsic properties including the thermosensitivity (e.g., the body temperature-induced sol-gel transition), non-cytotoxicity, and controlled drug release. A detailed study on the sol-gel-sol transition behavior of different copolymers showed that an appropriate extent of modification with DMA retained a sol-gel-sol transition, despite the fact that a too high extent caused a loss of sol-gel-sol transition. The hydrophilic and hydrophobic balance between mPEG and PCL was most likely broken upon a high extent of quaternization due to a large disturbance effect of DMA units at a large quantity (as evidenced by the heavily depressed PCL segment crystallinity), and thus the micelle aggregation mechanism for the gel formation could not work anymore, along with the loss of the thermosensitivity. The work presented here is highly expected to be generalized for synthesis of various block copolymers with immunity to microorganisms. Light may also be shed on understanding the phase transition behavior of various multiblock copolymers. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Comparison of Coatings from Reactive Star Shaped PEG-stat-PPG Prepolymers and Grafted Linear PEG for Biological and Medical Applications

    DEFF Research Database (Denmark)

    Groll, J.; Ademovic, Z.; Klee, D.

    2005-01-01

    ). In an alternative approach, surfaces were modified with layers prepared from isocyanate terminated, star shaped poly(ethylene glycol-stat-propylene glycol) prepolymers (80% ethylene glycol, six arms, M. = 3000, 12 000, and 18 000; this compound will be referred to as "Star PEG" in the text). Due to the highly......Grafting of poly(ethylene glycol) (PEG) is a common strategy for reducing nonspecific interactions of surfaces with proteins. We have used grafting at "cloud point" solution conditions that ensures maximum grafting density of linear methoxy terminated PEG-aldehyde (mPEG-ald, M-W = 5000 and 30000....... Protein adsorption was monitored by surface MALDI-TOF MS and fluorescence microscopy. No protein adsorption could be detected on Star PEG coatings and on mPEG-ald 5000, whereas mPEG-ald 30 000 could only prevent adsorption of lysozyme but not of the smaller insulin....

  13. Raman scattering studies on PEG functionalized hydroxyapatite nanoparticles

    Science.gov (United States)

    Yamini, D.; Devanand Venkatasubbu, G.; Kumar, J.; Ramakrishnan, V.

    2014-01-01

    The pure hydroxyapatite (HAP) nanoparticles (NPs) have been synthesized by wet chemical precipitation method. Raman spectral measurements have been made for pure HAP, pure Polyethylene glycol (PEG) 6000 and PEG coated HAP in different mass ratios (sample 1, sample 2 and sample 3). The peaks observed in Raman spectrum of pure HAP and the XRD pattern have confirmed the formation of HAP NPs. Vibrational modes have been assigned for pure HAP and pure PEG 6000. The observed variation in peak position of Raman active vibrational modes of PEG in PEG coated HAP has been elucidated in this work, in terms of intermolecular interactions between PEG and HAP. Further these results suggest that the functionalization of nanoparticles may be independent of PEG mass.

  14. Fast and facile fabrication of antifouling and hemocompatible PVDF membrane tethered with amino-acid modified PEG film

    Science.gov (United States)

    Zhang, Shuyou; Cao, Jingjing; Ma, Na; You, Meng; Wang, Xushan; Meng, Jianqiang

    2018-01-01

    A fast and facile protocol is reported aiming at improving the antifouling property and hemocompatibility of poly(vinylidene fluoride) (PVDF) membranes by tethering PEG hydrogel and zwitterion immobilization. The coated PEG hydrogel was first prepared by interfacial polymerization and tethered on an alkali treated PVDF membrane (PVDFA) surface via a simultaneous thio-ene and thiol-epoxy reaction. Then, the thiol groups of cysteine reacted with the epoxy groups in PEG hydrogel to fabricate the PVDFA-g-Cys membrane. The membrane fabrication was complete within less than 20 min and was conducted in mild conditions. The successful preparation of PVDFA-g-Cys membrane was confirmed by ATR-FTIR and XPS. Raman spectroscopy showed that the hydrogels covalently bonded to the PVDF membrane surface. The membrane retained its mechanical strength after modification. The SEM measurements suggested that the membrane became denser after hydrogel coating, meanwhile, the EDX test verified that the functional species uniformly distributed in the membrane matrix. Water contact angle (WCA), protein adsorption and protein filtration tests showed significant improvements in hydrophilicity and antifouling properties for the modified membrane. The negativity of the membrane surface measured by the streaming potential method provides a basis for protein resistance and hemocompatibility. Moreover, the suppressed platelet adhesion and prolonged plasma coagulant time show that the PVDFA-g-Cys membrane has ultralow thrombotic potential and better hemocompatibility. The reported surface modification method combing thio-ene and thio-epoxy chemistry not only facilitates fabrication of hemocompatible PVDF membrane but also provide an universal chemical platform for multifunctionalization of porous membranes.

  15. Intradiscal application of a PCLA-PEG-PCLA hydrogel loaded with celecoxib for the treatment of back pain in canines: What's in it for humans?

    Science.gov (United States)

    Tellegen, Anna R; Willems, Nicole; Beukers, Martijn; Grinwis, Guy C M; Plomp, Saskia G M; Bos, Clemens; van Dijk, Maarten; de Leeuw, Mike; Creemers, Laura B; Tryfonidou, Marianna A; Meij, Björn P

    2018-03-01

    Chronic low back pain is a common clinical problem in both the human and canine population. Current pharmaceutical treatment often consists of oral anti-inflammatory drugs to alleviate pain. Novel treatments for degenerative disc disease focus on local application of sustained released drug formulations. The aim of this study was to determine safety and feasibility of intradiscal application of a poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-bpoly(ε-caprolactone-co-lactide) PCLA-PEG-PCLA hydrogel releasing celecoxib, a COX-2 inhibitor. Biocompatibility was evaluated after subcutaneous injection in mice, and safety of intradiscal injection of the hydrogel was evaluated in experimental dogs with early spontaneous intervertebral disc (IVD) degeneration. COX-2 expression was increased in IVD samples surgically obtained from canine patients, indicating a role of COX-2 in clinical IVD disease. Ten client-owned dogs with chronic low back pain related to IVD degeneration received an intradiscal injection with the celecoxib-loaded hydrogel. None of the dogs showed adverse reactions after intradiscal injection. The hydrogel did not influence magnetic resonance imaging signal at long-term follow-up. Clinical improvement was achieved by reduction of back pain in 9 of 10 dogs, as was shown by clinical examination and owner questionnaires. In 3 of 10 dogs, back pain recurred after 3 months. This study showed the safety and effectiveness of intradiscal injections in vivo with a thermoresponsive PCLA-PEG-PCLA hydrogel loaded with celecoxib. In this set-up, the dog can be used as a model for the development of novel treatment modalities in both canine and human patients with chronic low back pain. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Investigation of PEG crystallization in frozen PEG-sucrose-water solutions. I. Characterization of the nonequilibrium behavior during freeze-thawing.

    Science.gov (United States)

    Bhatnagar, Bakul S; Martin, Susan M; Teagarden, Dirk L; Shalaev, Evgenyi Y; Suryanarayanan, Raj

    2010-06-01

    Our objective was to characterize the nonequilibrium thermal behavior of frozen aqueous solutions containing PEG and sucrose. Aqueous solutions of (i) sucrose (10%, w/v) with different concentrations of PEG (1-20%, w/v), and (ii) PEG (10%, w/v) with different concentrations of sucrose (2-20%, w/v), were cooled to -70 degrees C at 5 degrees C/min and heated to 25 degrees C at 2 degrees C/min in a differential scanning calorimeter. Annealing was performed at temperatures ranging from -50 to -20 degrees C for 2 or 6 h. Similar experiments were also performed in the low-temperature stage of a powder X-ray diffractometer. A limited number of additional DSC experiments were performed wherein the samples were cooled to -100 degrees C. In unannealed systems with a fixed sucrose concentration (10%, w/v), the T'g decreased from -35 to -48 degrees C when PEG concentration was increased from 1% to 20% (w/v). On annealing at -25 degrees C, PEG crystallized. This was evident from the increase in T'g and the appearance of a secondary melting endotherm in the DSC. Low-temperature XRD provided direct evidence of PEG crystallization. Annealing at temperatures PEG concentration (10%, w/v), the T'g increased from -50 to -40 degrees C when sucrose concentration was increased from 5% to 50%, w/v. As the annealing time increased (at -25 degrees C), the T'g approached that of a sucrose-water system, reflecting progressive PEG crystallization. A second glass transition at approximately -65 degrees C was evident in unannealed systems [10%, w/v sucrose and 10 (or 20%), w/v PEG] cooled to -100 degrees C. Investigation of the nonequilibrium behavior of frozen PEG-sucrose-water ternary system revealed phase separation in the freeze-concentrate. Annealing facilitated PEG crystallization. (c) 2010 Wiley-Liss, Inc. and the American Pharmacists Association

  17. Drop Printing of Pharmaceuticals: Effect of Molecular Weight on PEG Coated-Naproxen/PEG3350 Solid Dispersions.

    Science.gov (United States)

    Hsu, Hsin-Yun; Toth, Scott; Simpson, Garth J; Harris, Michael T

    2015-12-01

    Solid dispersions have been used to enhance the bioavailability of poorly water-soluble active pharmaceutical ingredients (APIs). However, the solid state phase, compositional uniformity, and scale-up problems are issues that need to be addressed. To allow for highly controllable products, the Drop Printing (DP) technique can provide precise dosages and predictable compositional uniformity of APIs in two/three dimensional structures. In this study, DP was used to prepare naproxen (NAP)/polyethylene glycol 3350 (PEG3350) solid dispersions with PEG coatings of different molecular weights (MW). A comparison of moisture-accelerated crystallization inhibition by different PEG coatings was assessed. Scanning electron microscopy (SEM), second harmonic generation (SHG) microscopy, and differential scanning calorimetry (DSC) analysis were performed to characterize the morphology and quantify the apparent crystallinity of NAP within the solid dispersions. Thermogravimetric analysis (TGA) was employed to measure the water content within each sample. The results suggest that the moisture-accelerated crystallization inhibition capability of the PEG coatings increased with increasing MW of the PEG coating. Besides, to demonstrate the flexibility of DP technology on manufacturing formulation, multilayer tablets with different PEG serving as barrier layers were also constructed, and their dissolution behavior was examined. By applying DP and appropriate materials, it is possible to design various carrier devices used to control the release dynamics of the API.

  18. Evaluation of Clensia®, a new low-volume PEG bowel preparation in colonoscopy: Multicentre randomized controlled trial versus 4L PEG.

    Science.gov (United States)

    Spada, Cristiano; Cesaro, Paola; Bazzoli, Franco; Saracco, Giorgio Maria; Cipolletta, Livio; Buri, Luigi; Crosta, Cristiano; Petruzziello, Lucio; Ceroni, Liza; Fuccio, Lorenzo; Giordanino, Chiara; Elia, Chiara; Rotondano, Gianluca; Bianco, Maria A; Simeth, Catrin; Consalvo, Danilo; De Roberto, Giuseppe; Fiori, Giancarla; Campanale, Mariachiara; Costamagna, Guido

    2017-06-01

    Success of colonoscopy is linked to the adequacy of bowel cleansing. Polyethylene glycol 4L (PEG 4L) solutions are widely used for colonic cleansing but with limitations concerning tolerability and acceptability. To demonstrate the equivalence of a new low-volume PEG containing citrates and simeticone (Clensia) versus a standard PEG 4L. In this, multicentre, randomised, observer-blind trial, patients received either Clensia 2L or PEG 4L solution. Primary endpoint was the proportion of patients with colon cleansing evaluated as excellent or good. 422 patients received Clensia (n=213) or PEG 4L (n=209). Rate of excellent/good bowel cleansing was 73.6% and 72.3% in Clensia and PEG 4L group respectively. Clensia was demonstrated to be equivalent to PEG 4L. No SAEs were observed. Clensia showed better gastrointestinal tolerability (37.0% vs 25.4%). The acceptability was significantly better with Clensia in terms of proportion of subjects who felt no distress (Clensia 72.8% vs PEG 4L 63%, P=0.0314) and willingness-to-repeat (93.9% vs 82.2%, P=0.0002). The rate of optimal compliance was similar with both formulations (91.1% for Clensia vs 90.9% for PEG 4L, P=0.9388). The low-volume Clensia is equally effective and safe in bowel cleansing compared to the standard PEG 4L, with better gastrointestinal tolerability and acceptability. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. [Enteral alimentation at home: why PEG now?].

    Science.gov (United States)

    Suzuki, Y; Hanyu, N; Kashiwagi, H; Kubo, T; Aoki, T

    1996-12-01

    The history of percutaneous endoscopic gastrostomy (PEG) is relatively short. In 1980, a report entitled "Gastrostomy without laparotomy: A percutaneous endoscopic technique" by Ponsky and Gaudere was first published in the Journal of Pediatric Surgery. Thereafter, PEG soon saw widespread use in Western countries because of its clinical efficacy and economy. It has been performed in about 170,000 cases annually in the US. In contrast, its spread in Japan has been extremely slow: only about 10,000 cases have undergone this procedure annually, and this number accounted for less than 5% of patients receiving enteral alimentation. The reason why PEG has not spread may be the medical insurance system in Japan and the local distaste for operation scarring. However, in consideration of the unprecedented ageing of society that is surely coming in the near future, the role of PEG in Japan must be reexamined. In this report, we presented the methodology of enteral alimentation at home by means of PEG, giving special consideration to: (1) "What points are improved by using enteral alimentation at home by means of PEG in various diseases; (2) dysphagia due to cerebral angiopathy; (3) terminal cancer; (4) otolaryngological diseases; and (5) Crohn disease. We also discussed "Why PEG is important now?" in performing enteral alimentation at home.

  20. PEMBUATAN DAN KARAKTERISASI MEMBRAN HIBRIDA KITOSAN-SILIKA- PEG

    Directory of Open Access Journals (Sweden)

    F Widhi Mahatmanti

    2013-02-01

    Full Text Available Membran kitosan mempunyai efektivitas pemisahan relatif tinggi tetapi kestabilan mekanik rendah. Untuk meningkatkan kestabilan perlu ditambahkan silika sehingga dihasilkan membran kitosan-silika. Sebagai bahan dasar silika digunakan natrium silikat yang diisolasi dari abu sekam padi. Dalam pembuatan membran kitosan-silika, plasticizer (polietilen glikol/PEG digunakan untuk meningkatkan kestabilan mekanik membran secara signifikan. Pembuatan membran kitosan-silika-PEG dilakukan dengan cara penguapan larutan dan pencetakan. Membran kitosan-silika-PEG dikarakterisasi sifat mekaniknya dengan menguji kekuatan tarik, persen perpanjangan dan Modulus Young, perubahan gugus fungsi, morfologi, sifat kristalinitas, kestabilan terhadap suhu, sifat hidrofilisitas, dan uji terhadap fluks air. Hasil penelitian menunjukkan bahwa membran kitosan-silika dengan komposisi kitosan/silika 1:0,8 mempunyai harga kuat tarik optimum. Penambahan PEG akan meningkatkan harga persen perpanjangan, tidak menunjukkan perubahan yang signifikan pada hasil uji FTIR dan XRD, tetapi meningkatkan sifat hidrofil seiring dengan meningkatnya konsentrasi PEG dan pH. Nilai Fluks air menurun dengan meningkatnya konsentrasi PEG, dimungkinkan PEG terjebak secara fisik dalam padatan komposit.

  1. The Optimal PEG for Kidney Preservation: A Preclinical Porcine Study

    Directory of Open Access Journals (Sweden)

    Sebastien Giraud

    2018-02-01

    Full Text Available University of Wisconsin (UW solution is not optimal for preservation of marginal organs. Polyethylene glycol (PEG could improve protection. Similarly formulated solutions containing either 15 or 20 g/L PEG 20 kDa or 5, 15 and 30 g/L PEG 35 kDa were tested in vitro on kidney endothelial cells, ex vivo on preserved kidneys, and in vivo in a pig kidney autograft model. In vitro, all PEGs provided superior preservation than UW in terms of cell survival, adenosine triphosphate (ATP production, and activation of survival pathways. Ex vivo, tissue injury was lower with PEG 20 kDa compared to UW or PEG 35 kDa. In vivo, function recovery was identical between UW and PEG 35 kDa groups, while PEG 20 kDa displayed swifter recovery. At three months, PEG 35 kDa 15 and 30 g/L animals had worse outcomes than UW, while 5 g/L PEG 35 kDa was similar. PEG 20 kDa was superior to both UW and PEG 35 kDa in terms of function and fibrosis development, with low activation of damage pathways. PEG 20 kDa at 15 g/L was superior to 20 g/L. While in vitro models did not discriminate between PEGs, in large animal models of transplantation we showed that PEG 20 kDa offers a higher level of protection than UW and that longer chains such as PEG 35 kDa must be used at low doses, such as found in Institut George Lopez (IGL1, 1g/L.

  2. Safety of PEGylated recombinant human full-length coagulation factor VIII (BAX 855) in the overall context of PEG and PEG conjugates.

    Science.gov (United States)

    Stidl, R; Fuchs, S; Bossard, M; Siekmann, J; Turecek, P L; Putz, M

    2016-01-01

    BAX 855 is a PEGylated human full-length recombinant factor VIII (rFVIII) based on licensed rFVIII (ADVATE). The applied PEGylation technology has been optimized to retain functionality of the FVIII molecule, improve its pharmacokinetic properties and allow less frequent injections while maintaining efficacy. The aim of this study was to confirm that the excellent safety profile of ADVATE remains unchanged after PEGylation. Non-clinical safety studies with BAX 855 and its respective unbound polyethylene glycol (PEG) were conducted in several species. The distribution of a single dose of radiolabelled BAX 855 was further investigated in rats. Publically available safety data on PEG alone and PEGylated biomolecules were summarized and reviewed for specific safety findings attributable to PEG or PEGylated biopharmaceuticals. Safety pharmacology studies in rabbits and macaques and repeated dose toxicity studies in rats and macaques identified no safety issues. Results of a distribution study in rats administered radiolabelled BAX 855 showed that radioactivity was completely excreted; urine was the major elimination route. A 28-day study in rats dosed with the unbound PEG constituent (PEG2ru20KCOOH) of BAX 855 showed no adverse or non-adverse effects. Safety data for PEG and PEG-protein conjugates indicate no safety concerns associated with PEG at clinically relevant dose levels. Although vacuolation of certain cell types has been reported in mammals, no such vacuolation was observed with BAX 855 or with the unbound PEG constituent. Non-clinical safety evaluation of PEG and BAX 855 identified no safety signals; the compound is now in clinical development for the treatment of patients with haemophilia A. © 2015 Baxalta Innovations GmbH. Haemophilia Published by John Wiley & Sons Ltd.

  3. Protein diffusion in photopolymerized poly(ethylene glycol) hydrogel networks

    International Nuclear Information System (INIS)

    Engberg, Kristin; Frank, Curtis W

    2011-01-01

    In this study, protein diffusion through swollen hydrogel networks prepared from end-linked poly(ethylene glycol)-diacrylate (PEG-DA) was investigated. Hydrogels were prepared via photopolymerization from PEG-DA macromonomer solutions of two molecular weights, 4600 Da and 8000 Da, with three initial solid contents: 20, 33 and 50 wt/wt% PEG. Diffusion coefficients for myoglobin traveling across the hydrogel membrane were determined for all PEG network compositions. The diffusion coefficient depended on PEG molecular weight and initial solid content, with the slowest diffusion occurring through lower molecular weight, high-solid-content networks (D gel = 0.16 ± 0.02 x 10 -8 cm 2 s -1 ) and the fastest diffusion occurring through higher molecular weight, low-solid-content networks (D gel = 11.05 ± 0.43 x 10 -8 cm 2 s -1 ). Myoglobin diffusion coefficients increased linearly with the increase of water content within the hydrogels. The permeability of three larger model proteins (horseradish peroxidase, bovine serum albumin and immunoglobulin G) through PEG(8000) hydrogel membranes was also examined, with the observation that globular molecules as large as 10.7 nm in hydrodynamic diameter can diffuse through the PEG network. Protein diffusion coefficients within the PEG hydrogels ranged from one to two orders of magnitude lower than the diffusion coefficients in free water. Network defects were determined to be a significant contributing factor to the observed protein diffusion.

  4. 5-FU-hydrogel inhibits colorectal peritoneal carcinomatosis and tumor growth in mice

    International Nuclear Information System (INIS)

    Wang, Yongsheng; Gong, Changyang; Yang, Li; Wu, Qinjie; Shi, Shuai; Shi, Huashan; Qian, Zhiyong; Wei, Yuquan

    2010-01-01

    Colorectal peritoneal carcinomatosis (CRPC) is a common form of systemic metastasis of intra-abdominal cancers. Intraperitoneal chemotherapy is a preferable option for colorectal cancer. Here we reported that a new system, 5-FU-loaded hydrogel system, can improve the therapeutic effects of intraperitoneal chemotherapy. A biodegradable PEG-PCL-PEG (PECE) triblock copolymer was successfully synthesized. The biodegradable and temperature sensitive hydrogel was developed to load 5-FU. Methylene blue-loaded hydrogel were also developed for visible observation of the drug release. The effects and toxicity of the 5-FU-hydrogel system were evaluated in a murine CRPC model. The hydrogel system is an injectable flowing solution at ambient temperature and forms a non-flowing gel depot at physiological temperature. 5-FU-hydrogel was subsequently injected into abdominal cavity in mice with CT26 cancer cells peritoneal dissemination. The results showed that the hydrogel delivery system prolonged the release of methylene blue; the 5-FU-hydrogel significantly inhibited the peritoneal dissemination and growth of CT26 cells. Furthermore, intraperitoneal administration of the 5-FU-hydrogel was well tolerated and showed less hematologic toxicity. Our data indicate that the 5-FU-hydrogel system can be considered as a new strategy for peritoneal carcinomatosis, and the hydrogel may provide a potential delivery system to load different chemotherapeutic drugs for peritoneal carcinomatosis of cancers

  5. Sustained Release of Protein Therapeutics from Subcutaneous Thermosensitive Biocompatible and Biodegradable Pentablock Copolymers (PTSgels

    Directory of Open Access Journals (Sweden)

    Elizabeth Schaefer

    2016-01-01

    Full Text Available Objective. To evaluate thermosensitive, biodegradable pentablock copolymers (PTSgel for sustained release and integrity of a therapeutic protein when injected subcutaneously. Materials and Methods. Five PTSgels with PEG-PCL-PLA-PCL-PEG block arrangements were synthesized. In vitro release of IgG from PTSgels and concentrations was evaluated at 37°C. Released IgG integrity was characterized by SDS-PAGE. In vitro disintegration for 10GH PTSgel in PBS was monitored at 37°C over 72 days using gravimetric loss and GPC analysis. Near-infrared IgG in PTSgel was injected subcutaneously and examined by in vivo imaging and histopathology for up to 42 days. Results. IgG release was modulated from approximately 7 days to more than 63 days in both in vitro and in vivo testing by varying polymer composition, concentration of PTSgel aqueous solution, and concentration of IgG. Released IgG in vitro maintained structural integrity by SDS-PAGE. Subcutaneous PTSgels were highly biocompatible and in vitro IgG release occurred in parallel with the disappearance of subcutaneous gel in vivo. Conclusions. Modulation of release of biologics to fit the therapeutic need can be achieved by varying the biocompatible and biodegradable PTSgel composition. Release of IgG parallels disappearance of the polymeric gel; hence, little or no PTSgel remains after drug release is complete.

  6. Synthesis of Highly Effective Novel Graphene Oxide-Polyethylene Glycol-Polyvinyl Alcohol Nanocomposite Hydrogel For Copper Removal

    Directory of Open Access Journals (Sweden)

    Eman Serag

    2017-10-01

    Full Text Available A novel Graphene oxide-polyethylene glycol and polyvinyl alcohol (GO-PEG-PVA triple network hydrogel were prepared to remove Copper(II ion from its aqueous solution. The structures, morphologies, and properties of graphene oxide (GO, the composite GO-PEG-PVA and PEG-PVA were characterized using FTIR, X-ray diffraction, Scanning Electronic Microscope and Thermal Gravimetric analysis. A series of systematic batch adsorption experiments were conducted to study the adsorption property of GO, GO-PEG-PVA hydrogel and PEG-PVA hydrogel under different conditions (e.g. pH, contact time and Cu2+ ions concentration. The high adsorption capacity, easy regeneration, and effective adsorption–desorption results proved that the prepared GO-PEG-PVA composite hydrogel could be an effective adsorbent in removing Cu2+ ion from its aqueous solution. The maximum adsorption capacities were found to be 917, 900 and 423 mg g–1 for GO-PEG-PVA hydrogel, GO and PEG-PVA hydrogel, respectively at pH 5, 25 °C and Cu2+ ions’ concentration 500 mg l–1. The removal efficiency of the recycled GO-PEG-PVA hydrogel were 83, 81, 80 and 79% for the first four times, which proved efficient reusability.

  7. Release behavior and intra-articular biocompatibility of celecoxib-loaded acetyl-capped PCLA-PEG-PCLA thermogels

    NARCIS (Netherlands)

    Petit, Audrey|info:eu-repo/dai/nl/371748461; Sandker, Marjan; Müller, Benno; Meyboom, Ronald; van Midwoud, Paul; Bruin, Peter; Redout, Everaldo M; Versluijs-Helder, Marjan|info:eu-repo/dai/nl/311472699; van der Lest, Chris H A; Buwalda, Sytze J|info:eu-repo/dai/nl/339146850; de Leede, Leo G J; Vermonden, Tina|info:eu-repo/dai/nl/275124517; Kok, Robbert Jan|info:eu-repo/dai/nl/170678326; Weinans, Harrie; Hennink, Wim E|info:eu-repo/dai/nl/070880409

    In this study, we investigated the in vitro and in vivo properties and performance of a celecoxib-loaded hydrogel based on a fully acetyl-capped PCLA-PEG-PCLA triblock copolymer. Blends of different compositions of celocoxib, a drug used for pain management in osteoarthritis, and the acetyl-capped

  8. PEG Grafted-Nanodiamonds for the Delivery of Gemcitabine.

    Science.gov (United States)

    Lu, Mingxia; Wang, Yu-Kai; Zhao, Jiacheng; Lu, Hongxu; Stenzel, Martina H; Xiao, Pu

    2016-12-01

    Carboxyl end-functionalized poly[poly(ethylene glycol) methyl ether methacrylate] [P(PEGMEMA)] and its block copolymer with gemcitabine substituted poly(N-hydroxysuccinimide methacrylate) [PGem-block-P(PEGMEMA)] are synthesized via reversible addition-fragmentation transfer (RAFT) polymerization. Then, two polymers are grafted onto the surface of amine-functionalized nanodiamonds to obtain [P(PEGMEMA)]-grafted nanodiamonds (ND-PEG) and [PGem-block-P(PEGMEMA)]-grafted nanodiamonds (ND-PF). Gemcitabine is physically absorbed to ND-PEG to produce ND-PEG (Gem). Two polymer-grafted nanodiamonds (i.e., with physically absorbed gemcitabine ND-PEG (Gem) and with chemically conjugated gemcitabine ND-PF) are characterized using attenuated total reflectance infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis. The drug release, cytotoxicity (to seed human pancreatic carcinoma AsPC-1 cells), and cellular uptake of ND-PEG (Gem) and ND-PF are also investigated. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Optimal Currency Basket Pegs for Developing and Emerging Economies

    OpenAIRE

    Joseph Daniels; Peter G. Toumanoff; Marc von der Ruhr

    2001-01-01

    The exchange rate arrangement represents an important policy choice for emerging and transitional economies as they strive to become stable and market-driven. A wide variety of arrangements have emerged, ranging from currency boards, basket-currency pegs and single-currency pegs to floating rates. Recently the IMF has recommended that, if the exchange value of a currency is to be pegged, it is better to peg to a basket of currencies rather than a single currency. Nonetheless, there has been l...

  10. A PEG-DA microfluidic device for chemotaxis studies

    International Nuclear Information System (INIS)

    Traore, Mahama Aziz; Behkam, Bahareh

    2013-01-01

    The study of cells in a well-defined and chemically programmable microenvironment is essential for a complete and fundamental understanding of the cell behaviors with respect to specific chemical compounds. Flow-free microfluidic devices that generate quasi-steady chemical gradients (spatially varying but temporally constant) have been demonstrated as effective chemotaxis assay platforms due to dissociating the effect of chemical cues from mechanical shear forces caused by fluid flow. In this work, we demonstrate the fabrication and characterization of a flow-free microfluidic platform made of polyethylene glycol diacrylate (PEG-DA) hydrogel. We have demonstrated that the mass transport properties of these devices can be customized by fabricating them from PEG-DA gels of four distinct molecular weights. In contrast to microfluidic devices developed using soft lithography; this class of devices can be realized using a more cost-effective approach of direct photopolymerization with fewer microfabrication steps. This microfluidic platform was tested by conducting a quantitative study of the chemotactic behavior of Escherichia coli (E. coli) RP437, a model microorganism, in presence of the chemo-effector, casamino-acids. Using the microfabrication and characterization methodology presented in this work, microfluidic platforms with well-defined and customizable diffusive properties can be developed to accommodate the study of a wide range of cell types. (paper)

  11. PEG minocycline-liposomes ameliorate CNS autoimmune disease.

    Directory of Open Access Journals (Sweden)

    Wei Hu

    Full Text Available Minocycline is an oral tetracycline derivative with good bioavailability in the central nervous system (CNS. Minocycline, a potent inhibitor of matrix metalloproteinase (MMP-9, attenuates disease activity in experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis (MS. Potential adverse effects associated with long-term daily minocycline therapy in human patients are concerning. Here, we investigated whether less frequent treatment with long-circulating polyethylene glycol (PEG minocycline liposomes are effective in treating EAE.Performing in vitro time kinetic studies of PEG minocycline-liposomes in human peripheral blood mononuclear cells (PBMCs, we determined that PEG minocycline-liposome preparations stabilized with CaCl(2 are effective in diminishing MMP-9 activity. Intravenous injections of PEG minocycline-liposomes every five days were as effective in ameliorating clinical EAE as daily intraperitoneal injections of minocycline. Treatment of animals with PEG minocycline-liposomes significantly reduced the number of CNS-infiltrating leukocytes, and the overall expression of MMP-9 in the CNS. There was also a significant suppression of MMP-9 expression and proteolytic activity in splenocytes of treated animals, but not in CNS-infiltrating leukocytes. Thus, leukocytes gaining access to the brain and spinal cord require the same absolute amount of MMP-9 in all treatment groups, but minocycline decreases the absolute cell number.Our data indicate that less frequent injections of PEG minocycline-liposomes are an effective alternative pharmacotherapy to daily minocycline injections for the treatment of CNS autoimmune diseases. Also, inhibition of MMP-9 remains a promising treatment target in EAE and patients with MS.

  12. Protein resistance of dextran and dextran-PEG copolymer films

    Science.gov (United States)

    Kozak, Darby; Chen, Annie; Bax, Jacinda; Trau, Matt

    2011-01-01

    The protein resistance of dextran and dextran-poly(ethylene glycol) (PEG) copolymer films was examined on an organosilica particle-based assay support. Comb-branched dextran-PEG copolymer films were synthesized in a two step process using the organosilica particle as a solid synthetic support. Particles modified with increasing amounts (0.1-1.2 mg m−2) of three molecular weights (10 000, 66 900, 400 000 g mol−1) of dextran were found to form relatively poor protein-resistant films compared to dextran-PEG copolymers and previously studied PEG films. The efficacy of the antifouling polymer films was found to be dependent on the grafted amount and its composition, with PEG layers being the most efficient, followed by dextran-PEG copolymers, and dextran alone being the least efficient. Immunoglobulin gamma (IgG) adsorption decreased from ~ 5 to 0.5 mg m−2 with increasing amounts of grafted dextran, but bovine serum albumin (BSA) adsorption increased above monolayer coverage (to ~2 mg m−2) indicating ternary adsorption of the smaller protein within the dextran layer. PMID:21614699

  13. Characterisation of Gliclazide-PEG 8000 Solid Dispersions

    African Journals Online (AJOL)

    Erah

    Purpose: The aim of the present study was to characterise gliclazide solid dispersions (SDs) ... Results: The solubility of gliclazide increased with increasing amount of PEG 8000 in aqueous medium. ... FTIR analysis demonstrated the absence of well-defined gliclazide - PEG 8000 .... voltage of 35 kV and 20 mA current. The.

  14. Final report on the safety assessment of Triethylene Glycol and PEG-4.

    Science.gov (United States)

    2006-01-01

    Triethylene Glycol and PEG-4 (polyethylene glycol) are polymers of ethylene oxide alcohol. Triethylene Glycol is a specific three-unit chain, whereas PEG-4 is a polymer with an average of four units, but may contain polymers ranging from two to eight ethylene oxide units. In the same manner, other PEG compounds, e.g., PEG-6, are mixtures and likely contain some Triethylene Glycol and PEG-4. Triethylene Glycol is a fragrance ingredient and viscosity decreasing agent in cosmetic formulations, with a maximum concentration of use of 0.08% in skin-cleansing products. Following oral doses, Triethylene Glycol and its metabolites are excreted primarily in urine, with small amounts released in feces and expired air. With oral LD50 values in rodents from 15 to 22 g/kg, this compound has little acute toxicity. Rats given short term oral doses of 3% in water showed no signs of toxicity, whereas all rats given 10% died by the 12th day of exposure. At levels up to 1 g/m3, rats exposed to aerosolized Triethylene Glycol for 6 h per day for 9 days showed no signs of toxicity. Rats fed a diet containing 4% Triethylene Glycol for 2 years showed no signs of toxicity. There were no treatment-related effects on rats exposed to supersaturated Triethylene Glycol vapor for 13 months nor in rats that consumed 0.533 cc Triethylene Glycol per day in drinking water for 13 months. Triethylene Glycol was not irritating to the skin of rabbits and produced only minimal injury to the eye. In reproductive and developmental toxicity studies in rats and mice, Triethylene Glycol did not produce biologically significant embryotoxicity or teratogenicity. However, some maternal toxicity was seen in dams given 10 ml/kg/day during gestation. Triethylene Glycol was not mutagenic or genotoxic in Ames-type assays, the Chinese hamster ovary mutation assay, and the sister chromatid exchange assays. PEG-4 is a humectant and solvent in cosmetic products, with a maximum concentration of use of 20% in the "other

  15. Preparation of Polyvinyl Pyrrolidone-Based Hydrogels by Radiation Induced Crosslinking with Potential Application as Wound Dressing

    International Nuclear Information System (INIS)

    Abd EI-Mohdy, H.L.; Hegazy, E.A.

    2009-01-01

    Polyvinyl pyrrolidone l polyethylene glycol hydrogels (PVP/ PEG) and PVP/ PEG/ Starch were prepared by irradiating the mixtures of aqueous solutions of PVP, PEG and starch with electron beam at different doses. Its properties were evaluated to identify their usability in wound dressing applications. Hydrogel dressing can protect injured skin and keep it appropriately moist to speed the healing process. The physical properties of the prepared hydrogels, such as gel content, swelling, water content and degree of water evaporation with varying composition and irradiation dose were examined to evaluate the usefulness of the hydrogels for wound dressing. The gel content increases with increasing PVP concentration due to increased crosslink density, and decreases with increasing the PEG concentration. PEG seems to act not only as plasticizer but also to modify the gel properties as gelation% and maximum swelling. Mechanical experiments were conducted for both of PVP/PEG and PVP/PEG/ Starch. The adding of PEG and starch to PVP significantly improve elongation and tensile strength of prepared hydrogels. The crystallinity of prepared hydrogels was investigated with varying their components. XRD studies indicated that the crystallinity in the gel was mainly due to PVP and decreased with enhanced starch content. The prepared hydrogels had sufficient strength to be used as wound dressing and could be considered as a good barrier against microbes

  16. Synthesis, characterization, and property of biodegradable PEG-PCL-PLA terpolymers with miktoarm star and triblock architectures as drug carriers.

    Science.gov (United States)

    Zhang, Yixin; Luo, Song; Liang, Yan; Zhang, Hai; Peng, Xinyu; He, Bin; Li, Sai

    2018-03-01

    A series of amphiphilic terpolymers with miktoarm star and triblock architectures of poly(ethylene glycol) (PEG), poly(ε-caprolactone) (PCL) and poly(l-lactide acid) (PLLA) or poly(DL-lactide acid) (PDLLA) terpolymers were synthesized as carriers for drug delivery. The architecture, molecular weight and crystallization behavior of the terpolymers were characterized. Anticancer drug doxorubicin was encapsulated in the micelles to investigate their drug loading properties. The miktoarm star terpolymers exhibited stronger crystallization capability, smaller size and better stability than that of triblock polymeric micelle, owing to the lower CMC values of miktoarm star polymeric micelle. Furthermore, the drug-loaded miktoarm star polymeric micelles showed the cumulative DOX release account of the micelles with PDLLA blocks was 65.3% while the release account of the corresponding micelles containing PLLA blocks was 45.2%. The IC 50 values of drug-loaded miktoarm star polymeric micelle were lower than triblock polymeric micelle. Meanwhile, Confocal laser scanning microscopy (CLSM) and Flow Cytometry results demonstrated that the miktoarm star micelles were more favorable for cellular internalization. The miktoarm star micelles with PDLLA blocks were promising carriers for anticancer drug delivery.

  17. Ballistic energy transport in PEG oligomers

    Directory of Open Access Journals (Sweden)

    Kireev Victor V.

    2013-03-01

    Full Text Available Energy transport between the terminal groups of the azido-PEG-succinimide ester compounds with a number of repeating PEG units of 0, 4, 8, and 12 was studied using relaxation-assisted two-dimensional infrared spectroscopy. The through-bond energy transport time, evaluated as the waiting time at which the cross peak maximum is reached, Tmax, was found to be linearly dependent on the chain length for chain lengths up to 60 Å suggesting a ballistic energy transport regime. The through-bond energy transport speed is found to be ca. 500 m/s. The cross-peak amplitude at the maximum decays exponentially with the chain length with a characteristic decay distance of 15.7 ± 1 Å. Substantial mode delocalization across the PEG bridge is found, which can support the energy propagation as a wavepacket.

  18. Cartilage-like mechanical properties of poly (ethylene glycol)-diacrylate hydrogels.

    Science.gov (United States)

    Nguyen, Quynhhoa T; Hwang, Yongsung; Chen, Albert C; Varghese, Shyni; Sah, Robert L

    2012-10-01

    Hydrogels prepared from poly-(ethylene glycol) (PEG) have been used in a variety of studies of cartilage tissue engineering. Such hydrogels may also be useful as a tunable mechanical material for cartilage repair. Previous studies have characterized the chemical and mechanical properties of PEG-based hydrogels, as modulated by precursor molecular weight and concentration. Cartilage mechanical properties vary substantially, with maturation, with depth from the articular surface, in health and disease, and in compression and tension. We hypothesized that PEG hydrogels could mimic a broad range of the compressive and tensile mechanical properties of articular cartilage. The objective of this study was to characterize the mechanical properties of PEG hydrogels over a broad range and with reference to articular cartilage. In particular, we assessed the effects of PEG precursor molecular weight (508 Da, 3.4 kDa, 6 kDa, and 10 kDa) and concentration (10-40%) on swelling property, equilibrium confined compressive modulus (H(A0)), compressive dynamic stiffness, and hydraulic permeability (k(p0)) of PEG hydrogels in static/dynamic confined compression tests, and equilibrium tensile modulus (E(ten)) in tension tests. As molecular weight of PEG decreased and concentration increased, hydrogels exhibited a decrease in swelling ratio (31.5-2.2), an increase in H(A0) (0.01-2.46 MPa) and E(ten) (0.02-3.5 MPa), an increase in dynamic compressive stiffness (0.055-42.9 MPa), and a decrease in k(p0) (1.2 × 10(-15) to 8.5 × 10(-15) m(2)/(Pa s)). The frequency-dependence of dynamic compressive stiffness amplitude and phase, as well as the strain-dependence of permeability, were typical of the time- and strain-dependent mechanical behavior of articular cartilage. H(A0) and E(ten) were positively correlated with the final PEG concentration, accounting for swelling. These results indicate that PEG hydrogels can be prepared to mimic many of the static and dynamic mechanical

  19. Polyethyleneglycol diacrylate hydrogels with plasmonic gold nanospheres incorporated via functional group optimization

    Science.gov (United States)

    Ponnuvelu, Dinesh Veeran; Kim, Seokbeom; Lee, Jungchul

    2017-12-01

    We present a facile method for the preparation of polyethyleneglycol diacrylate (PEG-DA) hydrogels with plasmonic gold (Au) nanospheres incorporated for various biological and chemical sensing applications. Plasmonic Au nanospheres were prepared ex situ using the standard citrate reduction method with an average diameter of 3.5 nm and a standard deviation of 0.5 nm, and evaluated for their surface functionalization process intended for uniform dispersion in polymer matrices. UV-Visible spectroscopy reveals the existence of plasmonic properties for pristine Au nanospheres, functionalized Au nanospheres, and PEG-DA with uniformly dispersed functionalized Au nanospheres (hybrid Au/PEG-DA hydrogels). Hybrid Au/PEG-DA hydrogels examined by using Fourier transform infra-red spectroscopy (FT-IR) exhibit the characteristic bands at 1635, 1732 and 2882 cm-1 corresponding to reaction products of OH- originating from oxidized product of citrate, -C=O stretching from ester bond, and C-H stretching of PEG-DA, respectively. Thermal studies of hybrid Au/PEG-DA hydrogels show three-stage decomposition with their stabilities up to 500 °C. Optical properties and thermal stabilities associated with the uniform dispersion of Au nanospheres within hydrogels reported herein will facilitate various biological and chemical sensing applications.

  20. Structural and biological properties of thermosensitive chitosan-graphene hybrid hydrogels for sustained drug delivery applications.

    Science.gov (United States)

    Saeednia, Leyla; Yao, Li; Berndt, Marcus; Cluff, Kim; Asmatulu, Ramazan

    2017-09-01

    Chitosan has the ability to make injectable thermosensitive hydrogels which has been highly investigated for drug delivery applications. The addition of nanoparticles is one way to increase the mechanical strength of thermosensitive chitosan hydrogel and subsequently and control the burst release of drug. Graphene nanoparticles have shown unique mechanical, optical and electrical properties which can be exploited for biomedical applications, especially in drug delivery. This study, have focused on the mechanical properties of a thermosensitive and injectable hybrid chitosan hydrogel incorporated with graphene nanoparticles. Scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD) have been used for morphological and chemical characterization of graphene infused chitosan hydrogels. The cell viability and cytotoxicity of graphene-contained hydrogels were analyzed using the alamarBlue ® technique. In-vitro methotrexate (MTX) release was investigated from MTX-loaded hybrid hydrogels as well. As a last step, to evaluate their efficiency as a cancer treatment delivery system, an in vitro anti-tumor test was also carried out using MCF-7 breast cancer cell lines. Results confirmed that a thermosensitive chitosan-graphene hybrid hydrogel can be used as a potential breast cancer therapy system for controlled delivery of methotrexate. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2381-2390, 2017. © 2017 Wiley Periodicals, Inc.

  1. PEG tubes: dealing with complications.

    Science.gov (United States)

    Malhi, Hardip; Thompson, Rosie

    A percutaneous endoscopic gastronomy tube can be used to deliver nutrition, hydration and medicines directly into the patient's stomach. Patients will require a tube if they are unable to swallow safely, putting them at risk of aspiration of food, drink and medicines into their lungs. It is vital that nurses are aware of the complications that may arise when caring for a patient with a PEG tube. It is equally important that nurses know how to deal with these complications or from where tc seek advice. This article provides a quick troubleshooting guide to help nurses deal with complications that can arise with PEG feeding.

  2. Electrospinning synthesis and characterization of PLA-PEG-MNPs composite fibrous membranes

    Science.gov (United States)

    Kumar, M.; Klimke, S.; Preiss, A.; Unruh, D.; Wengerowsky, D.; Lehmann, R.; Sindelar, R.; Klingelhöfer, G.; Boča, R.; Renz, F.

    2017-11-01

    An electrospinning technique was used to fabricate PLA, PLA-PEG and PLA-PEG-MNPs composite fibrous membranes. The morphology of electrospun composite membranes were characterized by scanning electron microscope. To test the potential availability of MNPs in PLA-PEG composite membranes, TG, Raman, Mössbauer, VSM and ICP-OES analysis were used. The PLA-PEG composite fibrous membranes showed the presence of MNPs, hence offers the possibility for magnetically triggered on-demand drug delivery.

  3. Integrating valve-inspired design features into poly(ethylene glycol) hydrogel scaffolds for heart valve tissue engineering.

    Science.gov (United States)

    Zhang, Xing; Xu, Bin; Puperi, Daniel S; Yonezawa, Aline L; Wu, Yan; Tseng, Hubert; Cuchiara, Maude L; West, Jennifer L; Grande-Allen, K Jane

    2015-03-01

    The development of advanced scaffolds that recapitulate the anisotropic mechanical behavior and biological functions of the extracellular matrix in leaflets would be transformative for heart valve tissue engineering. In this study, anisotropic mechanical properties were established in poly(ethylene glycol) (PEG) hydrogels by crosslinking stripes of 3.4 kDa PEG diacrylate (PEGDA) within 20 kDa PEGDA base hydrogels using a photolithographic patterning method. Varying the stripe width and spacing resulted in a tensile elastic modulus parallel to the stripes that was 4.1-6.8 times greater than that in the perpendicular direction, comparable to the degree of anisotropy between the circumferential and radial orientations in native valve leaflets. Biomimetic PEG-peptide hydrogels were prepared by tethering the cell-adhesive peptide RGDS and incorporating the collagenase-degradable peptide PQ (GGGPQG↓IWGQGK) into the polymer network. The specific amounts of RGDS and PEG-PQ within the resulting hydrogels influenced the elongation, de novo extracellular matrix deposition and hydrogel degradation behavior of encapsulated valvular interstitial cells (VICs). In addition, the morphology and activation of VICs grown atop PEG hydrogels could be modulated by controlling the concentration or micro-patterning profile of PEG-RGDS. These results are promising for the fabrication of PEG-based hydrogels using anatomically and biologically inspired scaffold design features for heart valve tissue engineering. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Development of injectable hydrogels for nucleus pulposus replacement

    Science.gov (United States)

    Thomas, Jonathan D.

    Intervertebral disc degeneration has been reported as the underlying cause for 75% of cases of lower back pain and is marked by dehydration of the nucleus pulposus within the intervertebral disc. There have been many implant designs to replace the nucleus pulposus. Some researchers have proposed the replacement of the nucleus pulposus with hydrogel materials. The insertion of devices made from these materials further compromises the annulus of the disc. An ideal nucleus replacement could be injected into the disc space and form a solid in vivo. However, injectable replacements using curing elastomers and thermoplastic materials are not ideal because of the potentially harmful exothermic heat evolved from their reactions and the toxicity of the reactants used. We propose a hydrogel system that can be injected as a liquid at 25°C and solidified to yield a hydrogel within the intervertebral disc at 37°C. In aqueous solutions, these polymers have Lower Critical Solution Temperatures (LCST) between 25-37°C, making them unique candidate materials for this application. Poly(N-isopropylacrylamide) (PNIPAAm) is the most widely studied LCST polymer due to its drastic transition near body temperature. However, by itself, pure PNIPAAm forms a hydrogel that has low water content and can readily undergo plastic deformation. To increase the water content and impart elasticity to PNIPAAm hydrogels, grafted and branched hydrogel systems were created that incorporated the thermogelling PNIPAAm and hydrophilic poly(ethylene glycol) (PEG). In this research, the effects of polymer composition and monomer to initiator ratio, which controls polymer MW, on the in vitro swelling properties (mass, chemical, and compressive mechanical stability) of hydrogels formed from aqueous solutions of these polymers were evaluated. Immersion studies were also conducted in solutions to simulate the osmotic environment of the nucleus pulposus. The effects of repeated compression and unloading cycles

  5. Catching the PEG-induced attractive interaction between proteins.

    Science.gov (United States)

    Vivarès, D; Belloni, L; Tardieu, A; Bonneté, F

    2002-09-01

    We present the experimental and theoretical background of a method to characterize the protein-protein attractive potential induced by one of the mostly used crystallizing agents in the protein-field, the poly(ethylene glycol) (PEG). This attractive interaction is commonly called, in colloid physics, the depletion interaction. Small-Angle X-ray Scattering experiments and numerical treatments based on liquid-state theories were performed on urate oxidase-PEG mixtures with two different PEGs (3350 Da and 8000 Da). A "two-component" approach was used in which the polymer-polymer, the protein-polymer and the protein-protein pair potentials were determined. The resulting effective protein-protein potential was characterized. This potential is the sum of the free-polymer protein-protein potential and of the PEG-induced depletion potential. The depletion potential was found to be hardly dependent upon the protein concentration but strongly function of the polymer size and concentration. Our results were also compared with two models, which give an analytic expression for the depletion potential.

  6. Assessment of percutaneous endoscopic gastrostomy (PEG) in head and neck cancer patients

    International Nuclear Information System (INIS)

    Kakuta, Risako; Matsuura, Kazuto; Noguchi, Tetsuya; Katagiri, Katsunori; Imai, Takayuki; Ishida, Eichi; Saijyo, Shigeru; Kato, Kengo

    2011-01-01

    As nutrition support for head and neck cancer patients who receive chemoradiotherapy (CRT) and whose oral cavity or pharynx is exposed to radiation, we perform percutaneous endoscopic gastrostomy (PEG) tube placement. We examined 235 patients who underwent PEG in our division between January 2003 and December 2009. For 64% of them, the purpose of performing PEG was nutrition support for CRT, of whom 74% actually used the tube. However, the situation varied according to the primary sites of patients. Forty-four percent of laryngeal cancer patients who underwent PEG actually used the tube, which was a significantly lower rate than others. Also, 81% of them removed the PEG tube within one year. These findings suggest that PEG-tube placement for nutrition support is not indispensable for all CRT cases. Therefore, we recommend performing PEG for oral, oropharyngeal, and hypopharyngeal cancer patients. (author)

  7. Electro-spun PLA-PEG-yarns for tissue engineering applications.

    Science.gov (United States)

    Kruse, Magnus; Greuel, Marc; Kreimendahl, Franziska; Schneiders, Thomas; Bauer, Benedict; Gries, Thomas; Jockenhoevel, Stefan

    2018-06-27

    Electro-spinning is widely used in tissue-engineered applications mostly in form of non-woven structures. The development of e-spun yarn opens the door for textile fabrics which combine the micro to nanoscale dimension of electro-spun filaments with three-dimensional (3D) drapable textile fabrics. Therefore, the aim of the study was the implementation of a process for electro-spun yarns. Polylactic acid (PLA) and polyethylene glycol (PEG) were spun from chloroform solutions with varying PLA/PEG ratios (100:0, 90:10, 75:25 and 50:50). The yarn samples produced were analyzed regarding their morphology, tensile strength, water uptake and cytocompatibility. It was found that the yarn diameter decreased when the funnel collector rotation was increasd, however, the fiber diameter was not influenced. The tensile strength was also found to be dependent on the PEG content. While samples composed of 100% PLA showed a tensile strength of 2.5±0.7 cN/tex, the tensile strength increased with a decreasing PLA content (PLA 75%/PEG 25%) to 6.2±0.5 cN/tex. The variation of the PEG content also influenced the viscosity of the spinning solutions. The investigation of the cytocompatibility with endothelial cells was conducted for PLA/PEG 90:10 and 75:25 and indicated that the samples are cytocompatible.

  8. Synthesis, characterization, and cytotoxicity of glutathione-PEG-iron oxide magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Paula S.; Santos, Marconi C. [Universidade Federal de São Paulo, UNIFESP, Exact and Earth Sciences Department (Brazil); Guzzi Cassago, Carolina Aparecida de [Universidade Estadual de Campinas, UNICAMP, Department of Biochemistry and Tissue Biology, Institute of Biology (Brazil); Bernardes, Juliana S. [National Nanotechnology Laboratory (LNNano), National Center for Energy and Materials (CNPEM) (Brazil); Jesus, Marcelo Bispo de [Universidade Estadual de Campinas, UNICAMP, Department of Biochemistry and Tissue Biology, Institute of Biology (Brazil); Seabra, Amedea B., E-mail: amedea.seabra@ufabc.edu.br [Universidade Federal de São Paulo, UNIFESP, Exact and Earth Sciences Department (Brazil)

    2016-12-15

    Recently, increasing interest is spent on the synthesis of superparamagnetic iron oxide nanoparticles, followed by their characterization and evaluation of cytotoxicity towards tumorigenic cell lines. In this work, magnetite (Fe{sub 3}O{sub 4}) nanoparticles were synthesized by the polyol method and coated with polyethylene glycol (PEG) and glutathione (GSH), leading to the formation of PEG-Fe{sub 3}O{sub 4} and GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles. The nanoparticles were characterized by state-of-the-art techniques: dynamic light scattering (DLS), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and superconducting quantum interference device (SQUID) magnetic measurements. PEG-Fe{sub 3}O{sub 4} and GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles have crystallite sizes of 10 and 5 nm, respectively, indicating compression in crystalline lattice upon addition of GSH on the nanoparticle surface. Both nanoparticles presented superparamagnetic behavior at room temperature, and AFM images revealed the regular spherical shape of the nanomaterials and the absence of particle aggregation. The average hydrodynamic sizes of PEG-Fe{sub 3}O{sub 4} and GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles were 69 ± 37 and 124 nm ± 75 nm, respectively. The cytotoxicity of both nanoparticles was screened towards human prostatic carcinoma cells (PC-3). The results demonstrated a decrease in PC-3 viability upon treatment with PEG-Fe{sub 3}O{sub 4} or GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles in a concentration-dependent manner. However, the cytotoxicity was not time-dependent. Due to the superparamagnetic behavior of PEG-Fe{sub 3}O{sub 4} or GSH-PEG-Fe{sub 3}O{sub 4} nanoparticles, upon the application of an external magnetic field, those nanoparticles can be guided to the target site yielding local toxic effects to tumor cells with minimal side effects to normal tissues, highlighting the promising uses of iron oxide nanoparticles in

  9. PEGYLATION OF αα-Hb USING SUCCINIMIDYL PROPIONIC ACID PEG 5K

    Science.gov (United States)

    Meng, Fantao; Tsai, Amy G.; Intaglietta, Marcos; Acharya, Seetharama A.

    2014-01-01

    PEGylation of intramolecularly crosslinked Hb has been studied here to overcome the limitation of dissociation of Hb tetramers. New hexa and deca PEGylated low oxygen affi nity PEG-αα-Hbs have been generated. Infl uence of PEG conjugation chemistry and the PEG shell structure on the functional properties as well as PEGylation induced plasma expander like properties of the protein has been delineated. The results have established that in the design of PEG-Hbs as oxygen therapeutics, the infl uence of conjugation chemistry and the PEG shell structure on the oxygen affi nity of Hb needs to be optimized independently besides optimizing the PEG shell structure for inducing resuscitation fluid like properties. PMID:24597567

  10. Fabrication and evaluation of thermosensitive chitosan/collagen/α, β-glycerophosphate hydrogels for tissue regeneration.

    Science.gov (United States)

    Dang, Qifeng; Liu, Kai; Zhang, Zhenzhen; Liu, Chengsheng; Liu, Xi; Xin, Ying; Cheng, Xiaoyu; Xu, Tao; Cha, Dongsu; Fan, Bing

    2017-07-01

    Thermosensitive hydrogels whose physiological properties are similar to extracellular matrix have been extensively used for tissue regeneration. Polysaccharides and proteins, as biocompatible substrates similar to bio-macromolecules that could be recognized by human body, are two preferred polymers for fabrication of such hydrogels. A series of novel thermosensitive hydrogels (CS-ASC-HGs) containing chitosan (CS) and acid-soluble collagen (ASC) were thus prepared, in the presence of α, β-glycerophosphate, to mimic extracellular microenvironment for tissue regeneration. Rheological measurements demonstrated excellent thermosensitivity. FT-IR and SEM indicated CS-ASC-HGs possessed 3D porous architectures with fibrous ASC, and the molecular structure of ASC was well-maintained in hydrogels. Hemolysis, acute toxicity, and cytotoxicity tests suggested CS-ASC-HGs were of good biocompatibility. CS-ASC-HGs were able to support the survival and proliferation of L929 cells encapsulated in them. Moreover, CS-ASC-HGs had better pH stability and biocompatibility than pure CS hydrogel. These results suggested that CS-ASC-HGs could serve as promising scaffolds for tissue regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Thermosensitive copolymeric hydrogels with the regulated temperature of a phase transition

    International Nuclear Information System (INIS)

    Samchenko, Yu.M.; Konovalova, V.V.; Korotich, E.I.; Poltoratskaya, T.P.; Pobegaj, A.A.; Burban, A.F.; Ul'berg, Z.R.; Samchenko, Yu.M.; Konovalova, V.V.; Korotich, E.I.; Poltoratskaya, T.P.; Pobegaj, A.A.; Burban, A.F.; Ul'berg, Z.R.

    2011-01-01

    The work is devoted to the methods of obtaining the thermosensitive copolymeric hydrogels based on the NIPAAm with acrylic acid and its derivatives such as acrylamide, acrylonitrile, and methylacrylate. The mechanisms of thermoinitiated phase transitions in hydrogel matrices and the regularities of the thermoinitiated release of model compounds and drugs (aniline, novocaine, and sodium diclofenac) from copolymeric hydrogel are investigated.

  12. [Tolerance, safety and efficacy of the one-day preparation of PEG3350 + bisacodyl compared to 2 days of PEG3350 + bisacodyl in pediatric patients].

    Science.gov (United States)

    Portillo Canizalez, Ligia Marcela; Blanco Rodriguez, Gerardo; Teyssier Morales, Gustavo; Penchyna Grub, Jaime; Trauernicht Mendieta, Sean; Zurita-Cruz, Jessie Nallely

    Multiple intestinal preparations have been used in children undergoing colonoscopy, with variable limitation due to acceptance, tolerance, and proper cleaning. The objective of this study was to compare the tolerability, safety and efficacy of the colonoscopy preparation with 1 day with PEG 3350 (poliethylenglycol) (4g/kg/day) + bisacodyl compared to 2 days of preparation with PEG 3350 (2g/kg/day) + bisacodyl in pediatric patients. A clinical, randomized, and blind trial was performed. Patients aged 2 to 18 years scheduled for colonoscopy were included. Patients were randomized into two groups: 1 day of preparation with PEG 3350 4g/kg/day + bisacodyl and 2 days of preparation with PEG 3350 2g/kg/day + bisacodyl. Through a questionnaire, physical examination and endoscopic evaluation (Boston scale), the tolerance, safety and efficacy of the 2 preparations to be evaluated were determined. Student's t test was performed for quantitative variables and χ 2 for qualitative variables. There were no significant differences in compliance rates, adverse effects, and extent of colonoscopic evaluation. Tolerance and safety between the intestinal preparation for 1-day colonoscopy with PEG 3350 (4g/kg/day) + bisacodyl and the 2-day preparation with PEG 3350 (2g/kg/day) + bisacodyl were similar. The quality of cleanliness was good in both groups, being partially more effective in the 1-day group with PEG 3350 (4g/kg/day). Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

  13. Overcoming the PEG-addiction: well-defined alternatives to PEG, from structure–property relationships to better defined therapeutics

    KAUST Repository

    Barz, Matthias

    2011-01-01

    Synthetic methods in polymer chemistry have evolved tremendously during the last decade. Nowadays more and more attention is devoted to the application of those tools in the development of the next generation of nanomedicines. Nevertheless, poly(ethylene glycol) (PEG) remains the most frequently used polymer for biomedical applications. In this review, we try to summarize recent efforts and developments in controlled polymerisation techniques that may allow alternatives to PEG based systems and can be used to improve the properties of future polymer therapeutics. © 2011 The Royal Society of Chemistry.

  14. PEG Enhancement for EM1 and EM2+ Missions

    Science.gov (United States)

    Von der Porten, Paul; Ahmad, Naeem; Hawkins, Matt

    2018-01-01

    NASA is currently building the Space Launch System (SLS) Block-1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. The next evolution of SLS, the Block-1B Exploration Mission 2 (EM-2), is currently being designed. The Block-1 and Block-1B vehicles will use the Powered Explicit Guidance (PEG) algorithm. Due to the relatively low thrust-to-weight ratio of the Exploration Upper Stage (EUS), certain enhancements to the Block-1 PEG algorithm are needed to perform Block-1B missions. In order to accommodate mission design for EM-2 and beyond, PEG has been significantly improved since its use on the Space Shuttle program. The current version of PEG has the ability to switch to different targets during Core Stage (CS) or EUS flight, and can automatically reconfigure for a single Engine Out (EO) scenario, loss of communication with the Launch Abort System (LAS), and Inertial Navigation System (INS) failure. The Thrust Factor (TF) algorithm uses measured state information in addition to a priori parameters, providing PEG with an improved estimate of propulsion information. This provides robustness against unknown or undetected engine failures. A loft parameter input allows LAS jettison while maximizing payload mass. The current PEG algorithm is now able to handle various classes of missions with burn arcs much longer than were seen in the shuttle program. These missions include targeting a circular LEO orbit with a low-thrust, long-burn-duration upper stage, targeting a highly eccentric Trans-Lunar Injection (TLI) orbit, targeting a disposal orbit using the low-thrust Reaction Control System (RCS), and targeting a hyperbolic orbit. This paper will describe the design and implementation of the TF algorithm, the strategy to handle EO in various flight regimes, algorithms to cover off-nominal conditions, and other enhancements to the Block-1 PEG algorithm. This paper illustrates challenges posed by the Block-1B vehicle, and results show that the improved PEG

  15. Paternally expressed Peg3 controls maternally expressed Zim1 as a trans factor.

    Directory of Open Access Journals (Sweden)

    An Ye

    Full Text Available The expression of two adjacent imprinted genes, Peg3 and Zim1, is inversely correlated: down-regulation of Peg3 coinciding with up-regulation of Zim1. The current study characterized this inverse correlation using a mutant allele targeting Peg3. According to the results, the mutation on the paternal allele of Peg3 resulted in a dramatic increase in the transcription levels of the maternal allele of Zim1, suggesting the involvement of unknown trans factors in this trans-allelic event. Subsequent ChIP experiments revealed that the protein encoded by Peg3 itself binds to the zinc finger exon of Zim1, which is modified with the repression mark H3K9me3. Interestingly, the levels of H3K9me3 on Zim1 are also reduced in the mutant cells lacking the protein PEG3, suggesting potential roles for PEG3 in establishing H3K9me3 on Zim1. Reintroducing PEG3 into the mutant cell restored down-regulation of Zim1, confirming the predicted repressor role for Peg3 on Zim1. Overall, these results demonstrated that paternally expressed Peg3 controls maternally expressed Zim1 as a trans factor. The current study also provides the first case for the trans-allelic interaction of two oppositely imprinted genes through their gene products.

  16. Angiogenic competency of biodegradable hydrogels fabricated from polyethylene glycol-crosslinked tyrosine-derived polycarbonates

    Directory of Open Access Journals (Sweden)

    HJ Sung

    2008-04-01

    Full Text Available Synthetic biomaterials can be used as instructive biological milieus to guide cellular behaviour and function. To further realize this application, we synthesized a series of structurally similar hydrogels and tested their ability to modulate angiogenesis. Hydrogels were synthesized from poly(DTE-co-x% DT carbonate crosslinked by y% poly(ethylene glycol (PEG. Hydrogel desaminotyrosyl tyrosine (DT contents (x% ranged from 10-100%, and crosslink densities (y% PEG-crosslinker ranged from 5-80%. The hydrogels were fashioned into porous scaffolds with highly interconnected macro- and micro-pore (>100 and <10 mm in diameter, respectively architecture using poly(DTE-co-10%DT carbonate crosslinked with 8% PEG. Under physiological conditions (in vitro, the hydrogels degraded into three major products: desaminotyrosyl-tyrosine ethyl ester (DTE, desaminotyrosyl tyrosine (DT, and poly(ethylene glycol-di-DT-hydrazide (PEG-di-DT hydrazide. Increasing either DT content or crosslink density brought quickened degradation. Because DT and DTE, two of the three major degradation products, have not demonstrated any noticeable cytotoxicity or angiogenic effect in previous studies, we measured the cytotoxicity of PEG-di-DT hydrazide, the third major degradation product. We found that PEG-di-DT hydrazide only displayed significant cytotoxicity at the high concentration of 100 mg/mL. Interestingly, PEG-di-DT hydrazide and its further degradation product PEG-dihydrazide stimulated in vitro endothelial cell migration and tubulogenesis, which is comparable to results found with FGF-beta treatment. Subcutaneous implantation of the PEG-crosslinked poly(DTE-co-10%DT carbonate scaffolds into the backs of rats elicited greater tissue growth over time and superior vascularization than poly(DTE carbonate implantation. These results show that this new class of biomaterials has a strong potential to modulate angiogenesis.

  17. Optimizing the Esthetics of peg-shaped teeth

    OpenAIRE

    Fabia Danielle Sales da Cunha Medeiros e Silva; Rosângela Marques Duarte; Ana Karina Maciel Andrade; Ricardo Jorge Alves Figueiredo

    2008-01-01

    In modern esthetic dentistry, recontouring peg-shaped teeth present the option of a technique for obtaining a harmonious smile. In thiscontext, the advancement of direct dental materials, such as resin composites and adhesive systems, allows this procedure to be performedsimply and efficiently, when compared with other available techniques. Thus, the aim of this report is to present a clinical case with an esthetic solution in peg-shaped lateral incisors (12 and 22). Initially, it was opted f...

  18. Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products

    International Nuclear Information System (INIS)

    Fruijtier-Poelloth, Claudia

    2005-01-01

    This assessment focusses on polyethylene glycols (PEGs) and on anionic or nonionic PEG derivatives, which are currently used in cosmetics in Europe. These compounds are used in a great variety of cosmetic applications because of their solubility and viscosity properties, and because of their low toxicity. The PEGs, their ethers, and their fatty acid esters produce little or no ocular or dermal irritation and have extremely low acute and chronic toxicities. They do not readily penetrate intact skin, and in view of the wide use of preparations containing PEG and PEG derivatives, only few case reports on sensitisation reactions have been published, mainly involving patients with exposure to PEGs in medicines or following exposure to injured or chronically inflamed skin. On healthy skin, the sensitising potential of these compounds appears to be negligible. For some representative substances of this class, information was available on reproductive and developmental toxicity, on genotoxicty and carcinogenic properties. Taking into consideration all available information from related compounds, as well as the mode and mechanism of action, no safety concern with regard to these endpoints could be identified. Based on the available data it is therefore concluded that PEGs of a wide molecular weight range (200 to over 10,000), their ethers (laureths. ceteths, ceteareths, steareths, and oleths), and fatty acid esters (laurates, dilaurates, stearates, distearates) are safe for use in cosmetics. Limited data were available for PEG sorbitan/sorbitol fatty acid esters, PEG sorbitan beeswax and PEG soy sterols. Taking into account all the information available for closely related compounds, it can be assumed that these compounds as presently used in cosmetic preparations will not present a risk for human health. PEG castor oils and PEG hydrogenated castor oils have caused anaphylactic reactions when used in intravenous medicinal products. Their topical use in cosmetics is

  19. Structural analysis of binding functionality of folic acid-PEG dendrimers against folate receptor.

    Science.gov (United States)

    Sampogna-Mireles, Diana; Araya-Durán, Ingrid D; Márquez-Miranda, Valeria; Valencia-Gallegos, Jesús A; González-Nilo, Fernando D

    2017-03-01

    Dendrimers functionalized with folic acid (FA) are drug delivery systems that can selectively target cancer cells with folate receptors (FR-α) overexpression. Incorporation of polyethylene glycol (PEG) can enhance dendrimers solubility and pharmacokinetics, but ligand-receptor binding must not be affected. In this work we characterized, at atomic level, the binding functionality of conventional site-specific dendrimers conjugated with FA with PEG 750 or PEG 3350 as a linker. After Molecular Dynamics simulation, we observed that both PEG's did not interfere over ligand-receptor binding functionality. Although binding kinetics could be notably affected, the folate fragment from both dendrimers remained exposed to the solvent before approaching selectively to FR-α. PEG 3350 provided better solubility and protection from enzymatic degradation to the dendrimer than PEG 750. Also, FA-PEG3350 dendrimer showed a slightly better interaction with FR-α than FA-PEG750 dendrimer. Therefore, theoretical evidence supports that both dendrimers are suitable as drug delivery systems for cancer therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. PEG/CaFe2O4 nanocomposite: Structural, morphological, magnetic and thermal analyses

    International Nuclear Information System (INIS)

    Khanna, Lavanya; Verma, Narendra K.

    2013-01-01

    The coating of Polyethylene Glycol (PEG) on calcium ferrite (CaFe 2 O 4 ) nanoparticles has been reported in the present study. The X-ray diffraction pattern revealed the formation of orthorhombic structure of bare CaFe 2 O 4 nanoparticles, which was also retained after the PEG coating, along with additional characteristic peaks of PEG at 19° and 23°. The rings of CaFe 2 O 4 nanoparticles were identified by the selected area electron diffraction pattern. The characteristic bands of PEG as observed in its Fourier transform infrared spectrum were also present in PEG coated CaFe 2 O 4 nanoparticles, hence confirming its presence. In the thermal gravimetric studies, the complete thermal decomposition of PEG occurred in a one step process, but in case of PEG coated CaFe 2 O 4 nanoparticles, the decomposition took place at a higher temperature owing to the formation of covalent bonds of PEG with CaFe 2 O 4 nanoparticles. The presence of PEG on CaFe 2 O 4 nanoparticles, spherical formation of PEG coated CaFe 2 O 4 nanoparticles and reduced agglomeration in the CaFe 2 O 4 nanoparticles were revealed by high resolution transmission electron microscope, transmission electron microscope and scanning electron microscope studies, respectively. In vibrating sample magnetometer analysis, both bare as well as coated CaFe 2 O 4 nanoparticles exhibited superparamagnetic behavior. However, a drop in the magnetic saturation value was observed from 36.76 emu/g for CaFe 2 O 4 nanoparticles to 6.74 emu/g for PEG coated CaFe 2 O 4 nanoparticles, due to the formation of magnetically dead layer of PEG. In ZFC and FC analyses, superparamagnetic behavior with blocking temperature for bare and coated nanoparticles has been observed at ∼40 K and ∼60 K, respectively. The increase in the blocking temperature is attributed to the increase in the particle size after PEG coating

  1. Biocompatible Porous Polyester-Ether Hydrogel Scaffolds with Cross-Linker Mediated Biodegradation and Mechanical Properties for Tissue Augmentation

    Directory of Open Access Journals (Sweden)

    Berkay Ozcelik

    2018-02-01

    Full Text Available Porous polyester-ether hydrogel scaffolds (PEHs were fabricated using acid chloride/alcohol chemistry and a salt templating approach. The PEHs were produced from readily available and cheap commercial reagents via the reaction of hydroxyl terminated poly(ethylene glycol (PEG derivatives with sebacoyl, succinyl, or trimesoyl chloride to afford ester cross-links between the PEG chains. Through variation of the acid chloride cross-linkers used in the synthesis and the incorporation of a hydrophobic modifier (poly(caprolactone (PCL, it was possible to tune the degradation rates and mechanical properties of the resulting hydrogels. Several of the hydrogel formulations displayed exceptional mechanical properties, remaining elastic without fracture at compressive strains of up to 80%, whilst still displaying degradation over a period of weeks to months. A subcutaneous rat model was used to study the scaffolds in vivo and revealed that the PEHs were infiltrated with well vascularised tissue within two weeks and had undergone significant degradation in 16 weeks without any signs of toxicity. Histological evaluation for immune responses revealed that the PEHs incite only a minor inflammatory response that is reduced over 16 weeks with no evidence of adverse effects.

  2. PEG-lipid micelles as drug carriers: physiochemical attributes, formulation principles and biological implication.

    Science.gov (United States)

    Gill, Kanwaldeep K; Kaddoumi, Amal; Nazzal, Sami

    2015-04-01

    PEG-lipid micelles, primarily conjugates of polyethylene glycol (PEG) and distearyl phosphatidylethanolamine (DSPE) or PEG-DSPE, have emerged as promising drug-delivery carriers to address the shortcomings associated with new molecular entities with suboptimal biopharmaceutical attributes. The flexibility in PEG-DSPE design coupled with the simplicity of physical drug entrapment have distinguished PEG-lipid micelles as versatile and effective drug carriers for cancer therapy. They were shown to overcome several limitations of poorly soluble drugs such as non-specific biodistribution and targeting, lack of water solubility and poor oral bioavailability. Therefore, considerable efforts have been made to exploit the full potential of these delivery systems; to entrap poorly soluble drugs and target pathological sites both passively through the enhanced permeability and retention (EPR) effect and actively by linking the terminal PEG groups with targeting ligands, which were shown to increase delivery efficiency and tissue specificity. This article reviews the current state of PEG-lipid micelles as delivery carriers for poorly soluble drugs, their biological implications and recent developments in exploring their active targeting potential. In addition, this review sheds light on the physical properties of PEG-lipid micelles and their relevance to the inherent advantages and applications of PEG-lipid micelles for drug delivery.

  3. Development practices and lessons learned in developing SimPEG

    Science.gov (United States)

    Cockett, R.; Heagy, L. J.; Kang, S.; Rosenkjaer, G. K.

    2015-12-01

    Inverse modelling provides a mathematical framework for constructing a model of physical property distributions in the subsurface that are consistent with the data collected in geophysical surveys. The geosciences are increasingly moving towards the integration of geological, geophysical, and hydrological information to better characterize the subsurface. This integration must span disciplines and is not only challenging scientifically, but additionally the inconsistencies between conventions often makes implementations complicated, non­ reproducible, or inefficient. SimPEG is an open-source, multi-university effort aimed at providing a generalized framework for solving forward and inverse problems. SimPEG includes finite volume discretizations on structured and unstructured meshes, interfaces to standard numerical solver packages, convex optimization algorithms, model parameterizations, and visualization routines. The SimPEG package (http://simpeg.xyz) supports an ecosystem of forward and inverse modelling applications, including electromagnetics, vadose zone flow, seismic, and potential­ fields, that are all written with a common interface and toolbox. The goal of SimPEG is to support a community of researchers with well-tested, extensible tools, and encourage transparency and reproducibility both of the SimPEG software and the geoscientific research it is applied to. In this presentation, we will share some of the lessons we have learned in designing the modular infrastructure, testing and development practices of SimPEG. We will discuss our use of version control, extensive unit-testing, continuous integration, documentation, issue tracking, and resources that facilitate communication between existing team members and allows new researchers to get involved. These practices have enabled the use of SimPEG in research, industry, and education as well as the ability to support a growing number of dependent repositories and applications. We hope that sharing our

  4. Debinding behaviour of a water soluble PEG/PMMA binder for Ti metal injection moulding

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gang [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Cao, Peng, E-mail: p.cao@auckland.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Wen, Guian [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Edmonds, Neil [School of Chemical Science, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand)

    2013-05-15

    Polyethylene glycol (PEG) has been becoming a common component in the design of water soluble binder systems for metal injection moulding. Similar to solvent debinding, PEG can be leached out by water and the mechanism of debinding was proposed in the literature with somehow misleading information about the debinding mechanism, particularly about the formation of PEG gel. This work investigates the debinding behaviours of a PEG-based binder in titanium compacts. Titanium powder is formulated with PEG, poly(methyl methacrylate) (PMMA) and stearic acid (SA) to formulate titanium feedstock. To determine the debinding kinetics, the PEG removal percentages are measured at three different temperatures and for various specimen thicknesses. A mathematic model based on diffusion-controlled debinding process is established. The evolution of porous microstructure during the water debinding process is observed using scanning electron microscopy. Based on these observations, a water debinding mechanism for titanium alloy compacts formulated with PEG-based binders is proposed. - Highlights: ► The water-debinding behaviours of the PEG binder system were investigated. ► PEG dissolution and transportation, and the pore structure development. ► A water debinding mechanism of PEG-based binders is proposed. ► Incorrect explanation of PEG gelling in the literature is corrected. ► Correction/modification made as per the reviewers' comments and suggestions.

  5. Debinding behaviour of a water soluble PEG/PMMA binder for Ti metal injection moulding

    International Nuclear Information System (INIS)

    Chen, Gang; Cao, Peng; Wen, Guian; Edmonds, Neil

    2013-01-01

    Polyethylene glycol (PEG) has been becoming a common component in the design of water soluble binder systems for metal injection moulding. Similar to solvent debinding, PEG can be leached out by water and the mechanism of debinding was proposed in the literature with somehow misleading information about the debinding mechanism, particularly about the formation of PEG gel. This work investigates the debinding behaviours of a PEG-based binder in titanium compacts. Titanium powder is formulated with PEG, poly(methyl methacrylate) (PMMA) and stearic acid (SA) to formulate titanium feedstock. To determine the debinding kinetics, the PEG removal percentages are measured at three different temperatures and for various specimen thicknesses. A mathematic model based on diffusion-controlled debinding process is established. The evolution of porous microstructure during the water debinding process is observed using scanning electron microscopy. Based on these observations, a water debinding mechanism for titanium alloy compacts formulated with PEG-based binders is proposed. - Highlights: ► The water-debinding behaviours of the PEG binder system were investigated. ► PEG dissolution and transportation, and the pore structure development. ► A water debinding mechanism of PEG-based binders is proposed. ► Incorrect explanation of PEG gelling in the literature is corrected. ► Correction/modification made as per the reviewers' comments and suggestions

  6. Optimizing the Esthetics of peg-shaped teeth

    Directory of Open Access Journals (Sweden)

    Fabia Danielle Sales da Cunha Medeiros e Silva

    2008-01-01

    Full Text Available In modern esthetic dentistry, recontouring peg-shaped teeth present the option of a technique for obtaining a harmonious smile. In thiscontext, the advancement of direct dental materials, such as resin composites and adhesive systems, allows this procedure to be performedsimply and efficiently, when compared with other available techniques. Thus, the aim of this report is to present a clinical case with an esthetic solution in peg-shaped lateral incisors (12 and 22. Initially, it was opted first to perform dental bleaching with a home bleaching gel (16% carbamide peroxide associated with an acetate mold duly made for this purpose. The peg-shaped teeth were recontoured with a microhybrid resin composite (shade EA1 and DA1 with the aid of a platinum guide in silicone, obtained after diagnostic waxing on the plaster model. It was concluded that the association of esthetic procedures is of the utmost importance for obtaining good looking, aligned and harmonious teeth.

  7. Thermo-sensitive injectable glycol chitosan-based hydrogel for treatment of degenerative disc disease.

    Science.gov (United States)

    Li, Zhengzheng; Shim, Hyeeun; Cho, Myeong Ok; Cho, Ik Sung; Lee, Jin Hyun; Kang, Sun-Woong; Kwon, Bosun; Huh, Kang Moo

    2018-03-15

    The use of injectable hydrogel formulations have been suggested as a promising strategy for the treatment of degenerative disc disease to both restore the biomechanical function and reduce low back pain. In this work, a new thermo-sensitive injectable hydrogels with tunable thermo-sensitivity and enhanced stability were developed with N-hexanoylation of glycol chitosan (GC) for treatment of degenerative disc disease, and their physico-chemical and biological properties were evaluated. The sol-gel transition temperature of the hydrogels was controlled in a range of 23-56 °С, depending on the degree of hexanoylation and the polymer concentration. In vitro and in vivo tests showed no cytotoxicity and no adverse effects in a rat model. The hydrogel filling of the defective IVD site in an ex vivo porcine model maintained its stability for longer than 28 days. These results suggest that the hydrogel can be used as an alternative material for treatment of disc herniation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Hydrogel Design for Supporting Neurite Outgrowth and Promoting Gene Delivery to Maximize Neurite Extension

    Science.gov (United States)

    Shepard, Jaclyn A.; Stevans, Alyson C.; Holland, Samantha; Wang, Christine E.; Shikanov, Ariella; Shea, Lonnie D.

    2012-01-01

    Hydrogels capable of gene delivery provide a combinatorial approach for nerve regeneration, with the hydrogel supporting neurite outgrowth and gene delivery inducing the expression of inductive factors. This report investigates the design of hydrogels that balance the requirements for supporting neurite growth with those requirements for promoting gene delivery. Enzymatically-degradable PEG hydrogels encapsulating dorsal root ganglia explants, fibroblasts, and lipoplexes encoding nerve growth factor were gelled within channels that can physically guide neurite outgrowth. Transfection of fibroblasts increased with increasing concentration of Arg-Gly-Asp (RGD) cell adhesion sites and decreasing PEG content. The neurite length increased with increasing RGD concentration within 10% PEG hydrogels, yet was maximal within 7.5% PEG hydrogels at intermediate RGD levels. Delivering lipoplexes within the gel produced longer neurites than culture in NGF-supplemented media or co-culture with cells exposed to DNA prior to encapsulation. Hydrogels designed to support neurite outgrowth and deliver gene therapy vectors locally may ultimately be employed to address multiple barriers that limit regeneration. PMID:22038654

  9. Intercellular coupling mediated by potassium accumulation in peg-and-socket junctions

    DEFF Research Database (Denmark)

    Vigmond, Edward J.; Bardakjian, Berj L.; Thuneberg, Lars

    2000-01-01

    Physiology, peg-and-socket junctions, smooth muscle, boundary element method, coupling, morphology......Physiology, peg-and-socket junctions, smooth muscle, boundary element method, coupling, morphology...

  10. Resilin-like polypeptide-poly(ethylene gylcol) hybrid hydrogels for mechanically-demanding tissue engineering applications

    Science.gov (United States)

    McGann, Christopher Leland

    Technological progress in the life sciences and engineering has combined with important insights in the fields of biology and material science to make possible the development of biological substitutes which aim to restore function to damaged tissue. Numerous biomimetic hydrogels have been developed with the purpose of harnessing the regenerative capacity of cells and tissue through the rational deployment of biological signals. Aided by recombinant DNA technology and protein engineering methods, a new class of hydrogel precursor, the biosynthetic protein polymer, has demonstrated great promise towards the development of highly functional tissue engineering materials. In particular, protein polymers based upon resilin, a natural protein elastomer, have demonstrated outstanding mechanical properties that would have great value in soft tissue applications. This dissertation introduces hybrid hydrogels composed of recombinant resilin-like polypeptides (RLPs) cross-linked with multi-arm PEG macromers. Two different chemical strategies were employed to form RLP-PEG hydrogels: one utilized a Michael-type addition reaction between the thiols of cysteine residues present within the RLP and vinyl sulfone moieties functionalized on a multi-arm PEG macromer; the second system cross-links a norbornene-functionalized RLP with a thiol-functionalized multi-arm PEG macromer via a photoinitiated thiol-ene step polymerization. Oscillatory rheology and tensile testing confirmed the formation of elastic, resilient hydrogels in the RLP-PEG system cross-linked via Michael-type addition. These hydrogels supported the encapsulation and culture of both human aortic adventitial fibroblasts and human mesenchymal stem cells. Additionally, these RLP-PEG hydrogels exhibited phase separation behavior during cross-linking that led to the formation of a heterogeneous microstructure. Degradation could be triggered through incubation with matrix metalloproteinase. Photocross-linking was conferred to

  11. Pore structure modified diatomite-supported PEG composites for thermal energy storage

    Science.gov (United States)

    Qian, Tingting; Li, Jinhong; Deng, Yong

    2016-09-01

    A series of novel composite phase change materials (PCMs) were tailored by blending PEG and five kinds of diatomite via a vacuum impregnation method. To enlarge its pore size and specific surface area, different modification approaches including calcination, acid treatment, alkali leaching and nano-silica decoration on the microstructure of diatomite were outlined. Among them, 8 min of 5 wt% NaOH dissolution at 70 °C has been proven to be the most effective and facile. While PEG melted during phase transformation, the maximum load of PEG could reach 70 wt.%, which was 46% higher than that of the raw diatomite. The apparent activation energy of PEG in the composite was 1031.85 kJ·mol-1, which was twice higher than that of the pristine PEG. Moreover, using the nano-silica decorated diatomite as carrier, the maximum PEG load was 66 wt%. The composite PCM was stable in terms of thermal and chemical manners even after 200 cycles of melting and freezing. All results indicated that the obtained composite PCMs were promising candidate materials for building applications due to its large latent heat, suitable phase change temperature, excellent chemical compatibility, improved supercooling extent, high thermal stability and long-term reliability.

  12. Pore structure modified diatomite-supported PEG composites for thermal energy storage.

    Science.gov (United States)

    Qian, Tingting; Li, Jinhong; Deng, Yong

    2016-09-01

    A series of novel composite phase change materials (PCMs) were tailored by blending PEG and five kinds of diatomite via a vacuum impregnation method. To enlarge its pore size and specific surface area, different modification approaches including calcination, acid treatment, alkali leaching and nano-silica decoration on the microstructure of diatomite were outlined. Among them, 8 min of 5 wt% NaOH dissolution at 70 °C has been proven to be the most effective and facile. While PEG melted during phase transformation, the maximum load of PEG could reach 70 wt.%, which was 46% higher than that of the raw diatomite. The apparent activation energy of PEG in the composite was 1031.85 kJ·mol(-1), which was twice higher than that of the pristine PEG. Moreover, using the nano-silica decorated diatomite as carrier, the maximum PEG load was 66 wt%. The composite PCM was stable in terms of thermal and chemical manners even after 200 cycles of melting and freezing. All results indicated that the obtained composite PCMs were promising candidate materials for building applications due to its large latent heat, suitable phase change temperature, excellent chemical compatibility, improved supercooling extent, high thermal stability and long-term reliability.

  13. Adsorption of polyethylene glycol (PEG) onto cellulose nano-crystals to improve its dispersity.

    Science.gov (United States)

    Cheng, Dong; Wen, Yangbing; Wang, Lijuan; An, Xingye; Zhu, Xuhai; Ni, Yonghao

    2015-06-05

    In this work, the adsorption of polyethylene glycol (PEG) onto cellulose nano-crystals (CNC) was investigated for preparing re-dispersible dried CNC. Results showed that the re-dispersity of CNC in water can be significantly enhanced using a PEG1000 dosage of 5wt% (based on the dry weight of CNC). The elemental analysis confirmed the adsorption of PEG onto the CNC surface. Transmission electron microscopy (TEM) was used to characterize the dry powder and indicated that the irreversible agglomeration of CNC after drying was essentially eliminated based on the PEG adsorption concept. Thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) suggested that CNC crystallinity and thermal stability were not affected by the adsorption of PEG. Thus, the adsorption of PEG has great potential for producing re-dispersible powder CNC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. PEG-stearate coated solid lipid nanoparticles as levothyroxine carriers for oral administration

    Science.gov (United States)

    Kashanian, Soheila; Rostami, Elham

    2014-03-01

    In this study, poly ethylene glycol 100 stearate (PEG 100-S) was used to prepare coated solid lipid nanoparticles with loading levothyroxine sodium (levo-loaded PEG 100-S-coated SLNs) by microemulsification technique. Evaluation of the release kinetic of prepared colloidal carriers was conducted. The particle size and zeta potential of levo-loaded PEG 100-S-coated SLNs have been measured to be 187.5 nm and -23.0 mV, respectively, using photon correlation spectroscopy (PCS). Drug entrapment efficiency (EE) was calculated to be 99 %. Differential scanning calorimetry indicated that the majority of drug loaded in PEG 100-S-coated SLNs were in amorphous state which could be considered desirable for drug delivery. The purpose of this study was to develop a new nanoparticle system, consisting lipid nanoparticles coated with PEG 100-S. The modification procedure led to a reduction in the zeta potential values, varying from -40.0 to -23.0 mV for the uncoated and PEG-coated SLNs, respectively. Stability results of the nanoparticles in gastric and intestinal media show that the low pH of the gastric medium is responsible for the critical aggregation and degradation of the uncoated lipid nanoparticles. PEG 100-S-coated SLNs were more stable due to their polymer coating layer which prevented aggregation of SLNs. Consequently, it is possible that the PEG surrounds the particles reducing the attachment of enzymes and further degradation of the triglyceride cores. Shape and surface morphology of particles were determined by transition electron microscopy and scanning electron microscopy that revealed spherical shape of nanoparticles. In vitro drug release of PEG 100-S-coated SLNs was characterized using diffusion cell which showed a controlled release for drug.

  15. Preparation and characterization of PEG-modified PCL nanoparticles for oxygen carrier: a new application of Fourier transform infrared spectroscopy for quantitative analysis of the hemoglobin in nanoparticles.

    Science.gov (United States)

    Shan, Xiaoqian; Yuan, Yuan; Liu, Changsheng

    2015-01-01

    The influence of polyethylene glycol (PEG) molar ratio on the nanoparticles (NPs) properties is described herein. Especially, a facile and nondestructive determination route has been raised to quantify the hemoglobin (Hb) amounts in NPs via an internal standard FTIR method. The subsequent results indicated that, briefly, the PEG molar ratio did negligible influence on the size distribution of NPs, however, it did have great effect on the NPs zeta potential and hydrophilicity as well as the Hb loading amount. These findings highlight that the PEG density on the surface is a key parameter affecting the NPs properties.

  16. Physicochemical characterization of spray-dried PLGA/PEG microspheres, and preliminary assessment of biological response.

    Science.gov (United States)

    Javiya, Curie; Jonnalagadda, Sriramakamal

    2016-09-01

    The use of spray-drying to prepare blended PLGA:PEG microspheres with lower immune detection. To study physical properties, polymer miscibility and alveolar macrophage response for blended PLGA:PEG microspheres prepared by a laboratory-scale spray-drying process. Microspheres were prepared by spray-drying 0-20% w/w ratios of PLGA 65:35 and PEG 3350 in dichloromethane. Particle size and morphology was studied using scanning electron microscopy. Polymer miscibility and residual solvent levels evaluated by thermal analysis (differential scanning calorimetry - DSC and thermogravimetric analysis - TGA). Immunogenicity was assessed in vitro by response of rat alveolar macrophages (NR8383) by the MTT-based cell viability assay and reactive oxygen species (ROS) detection. The spray dried particles were spherical, with a size range of about 2-3 µm and a yield of 16-60%. Highest yield was obtained at 1% PEG concentration. Thermal analysis showed a melting peak at 59 °C (enthalpy: 170.61 J/g) and a degradation-onset of 180 °C for PEG 3350. PLGA 65:35 was amorphous, with a Tg of 43 °C. Blended PLGA:PEG microspheres showed a delayed degradation-onset of 280 °C, and PEG enthalpy-loss corresponding to 15% miscibility of PEG in PLGA. NR8383 viability studies and ROS detection upon exposure to these cells suggested that blended PLGA:PEG microspheres containing 1 and 5% PEG are optimal in controling cell proliferation and activation. This research establishes the feasibility of using a spray-drying process to prepare spherical particles (2-3 µm) of molecularly-blended PLGA 65:35 and PEG 3350. A PEG concentration of 1-5% was optimal to maximize process yield, with minimal potential for immune detection.

  17. Graphene oxide stabilized by PLA-PEG copolymers for the controlled delivery of paclitaxel.

    Science.gov (United States)

    Angelopoulou, A; Voulgari, E; Diamanti, E K; Gournis, D; Avgoustakis, K

    2015-06-01

    To investigate the application of water-dispersible poly(lactide)-poly(ethylene glycol) (PLA-PEG) copolymers for the stabilization of graphene oxide (GO) aqueous dispersions and the feasibility of using the PLA-PEG stabilized GO as a delivery system for the potent anticancer agent paclitaxel. A modified Staudenmaier method was applied to synthesize graphene oxide (GO). Diblock PLA-PEG copolymers were synthesized by ring-opening polymerization of dl-lactide in the presence of monomethoxy-poly(ethylene glycol) (mPEG). Probe sonication in the presence of PLA-PEG copolymers was applied in order to reduce the hydrodynamic diameter of GO to the nano-size range according to dynamic light scattering (DLS) and obtain nano-graphene oxide (NGO) composites with PLA-PEG. The composites were characterized by atomic force microscopy (AFM), thermogravimetric analysis (TGA), and DLS. The colloidal stability of the composites was evaluated by recording the size of the composite particles with time and the resistance of composites to aggregation induced by increasing concentrations of NaCl. The composites were loaded with paclitaxel and the in vitro release profile was determined. The cytotoxicity of composites against A549 human lung cancer cells in culture was evaluated by flow cytometry. The uptake of FITC-labeled NGO/PLA-PEG by A549 cells was also estimated with flow cytometry and visualized with fluorescence microscopy. The average hydrodynamic diameter of NGO/PLA-PEG according to DLS ranged between 455 and 534 nm, depending on the molecular weight and proportion of PLA-PEG in the composites. NGO/PLA-PEG exhibited high colloidal stability on storage and in the presence of high concentrations of NaCl (far exceeding physiological concentrations). Paclitaxel was effectively loaded in the composites and released by a highly sustained fashion. Drug release could be regulated by the molecular weight of the PLA-PEG copolymer and its proportion in the composite. The paclitaxel

  18. In vitro studies of PEG thin films with different molecular weights deposited by MAPLE

    DEFF Research Database (Denmark)

    Paun, Irina Alexandra; Ion, Valentin; Luculescu, Catalin-Romeo

    2012-01-01

    and their behavior in vitro. Thus, immersion in PBS induced swelling of the PEG films, which was more pronounced for PEG polymers of higher molecular weight. Prior to immersion in PBS, the PEG films of higher molecular weight were more hydrophilic, the water contact angles decreasing from ∼66 grd for PEG400 to ∼41...

  19. Application of microchip CGE for the analysis of PEG-modified recombinant human granulocyte-colony stimulating factors.

    Science.gov (United States)

    Park, Eun Ji; Lee, Kyung Soo; Lee, Kang Choon; Na, Dong Hee

    2010-11-01

    The purpose of this study was to evaluate the microchip CGE (MCGE) for the analysis of PEG-modified granulocyte-colony stimulating factor (PEG-G-CSF) prepared with PEG-aldehydes. The unmodified and PEG-modified G-CSFs were analyzed by Protein 80 and 230 Labchips on the Agilent 2100 Bioanalyzer. The MCGE allowed size-based separation and quantitation of PEG-G-CSF. The Protein 80 Labchip was useful for PEG-5K-G-CSF, while the Protein 230 Labchip was more suitable for PEG-20K-G-CSF. The MCGE was also used to monitor a search for optimal PEG-modification (PEGylation) conditions to produce mono-PEG-G-CSF. This study demonstrates the usefulness of MCGE for monitoring and optimizing the PEGylation of G-CSF with the advantages of speed, minimal sample consumption, and automatic quantitation.

  20. Conditional internalization of PEGylated nanomedicines by PEG engagers for triple negative breast cancer therapy

    Science.gov (United States)

    Su, Yu-Cheng; Burnouf, Pierre-Alain; Chuang, Kuo-Hsiang; Chen, Bing-Mae; Cheng, Tian-Lu; Roffler, Steve R.

    2017-06-01

    Triple-negative breast cancer (TNBC) lacks effective treatment options due to the absence of traditional therapeutic targets. The epidermal growth factor receptor (EGFR) has emerged as a promising target for TNBC therapy because it is overexpressed in about 50% of TNBC patients. Here we describe a PEG engager that simultaneously binds polyethylene glycol and EGFR to deliver PEGylated nanomedicines to EGFR+ TNBC. The PEG engager displays conditional internalization by remaining on the surface of TNBC cells until contact with PEGylated nanocarriers triggers rapid engulfment of nanocargos. PEG engager enhances the anti-proliferative activity of PEG-liposomal doxorubicin to EGFR+ TNBC cells by up to 100-fold with potency dependent on EGFR expression levels. The PEG engager significantly increases retention of fluorescent PEG probes and enhances the antitumour activity of PEGylated liposomal doxorubicin in human TNBC xenografts. PEG engagers with specificity for EGFR are promising for improved treatment of EGFR+ TNBC patients.

  1. Preparation of various hydrogels based on poly (Vinyl pyrrolidone) and poly ethylene glycol using gamma and electron irradiation

    International Nuclear Information System (INIS)

    Ajji, Z.

    2006-11-01

    Different hydrogels have been prepared using gamma and electron irradiation; the hydrogels are composed of poly(vinyl pyrolidone) (PVP), poly(ethylene glycol) (PEG). The influence of some process parameters on the properties of the hydrogels has been investigated as: the gel fraction, maximum swelling, swelling kinetics, and mechanical properties. In the first part of this study, hydrogel dressings have been prepared using electron irradiation, and the dressings are composed of poly(vinyl pyrrolidone) (PVP), poly(ethylene glycol) (PEG) and agar. The gel fraction increases with increasing PVP concentration due to increased crosslink density, and decreases with increasing the PEG concentration. PEG seems to act not only as plasticizer but also to modify the gel properties as gelation% and maximum swelling. The prepared hydrogels dressings could be considered as a good barrier against microbes. In the second part, different hydrogels have been prepared based on different concentrations of poly(vinyl pyrrolidone) and using gamma irradiation. The gel fraction and maximum swelling of the hydrogels has been determined. In the third part of the study, different hydrogels have been prepared based on different concentrations of poly(vinyl pyrrolidone) and poly(ethylene glycol) (PEG) with various molecular weights, and using gamma irradiation. The gel fraction and maximum swelling of the hydrogels has been determined. The data show that PEG with low molecular weight needs a high dose for the gelation, and the presence of PVP lowers the needed gelation dose. The maximum swelling decreases with increasing irradiation dose and the PVP concentration, which is due to higher crosslinks between the polymer chains. (author)

  2. Generation, characterization and in vivo biological activity of two distinct monoclonal anti-PEG IgMs

    International Nuclear Information System (INIS)

    Hashimoto, Yosuke; Shimizu, Taro; Mima, Yu; Abu Lila, Amr S.; Ishida, Tatsuhiro; Kiwada, Hiroshi

    2014-01-01

    PEGylation, the attachment of polyethylene glycol (PEG) to nanocarriers and proteins, is a widely accepted approach to improving the in vivo efficacy of the non-PEGylated products. However, both PEGylated liposomes and PEGylated proteins reportedly trigger the production of specific antibodies, mainly IgM, against the PEG moiety, which possibly leads to a reduction in safety and therapeutic efficacy of the PEGylated products. In the present study, two monoclonal anti-PEG IgMs — HIK-M09 via immunization with an intravenous injection of PEGylated liposomes (SLs) and HIK-M11 via immunization with a subcutaneous administration of PEGylated ovalbumin (PEG-OVA) were successfully generated. The generated IgMs showed efficient reactivity to mPEG 2000 conjugated to 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine (DSPE), PEGylated liposome (SL) and PEG-OVA. It appears that HIK-M09 recognizes ethoxy (OCH 2 CH 2 ) repeat units along with a terminal motif of PEG, while HIK-M11 recognizes only ethoxy repeat units of PEG. Such unique properties allow HIK-M09 to bind with dense PEG. In addition, their impact on the in vivo clearance of the PEGylated products was investigated. It was found that the generated ant-PEG IgMs induced a clearance of SL as they were intravenously administered with SL. Interestingly, the HIK-M11, generated by PEG-OVA, induced the clearance of both SL and PEG-OVA, while the HIK-M09, generated by SL, induced the clearance of SL only. We here revealed that the presence of serum anti-PEG IgM and the subsequent binding of anti-PEG IgM to the PEGylated products are not necessarily related to the enhanced clearance of the products. It appears that subsequent complement activation following anti-PEG IgM binding is the most important step in dictating the in vivo fate of PEGylated products. This study may have implications for the design, development and clinical application of PEGylated products and therapeutics. - Highlights: • Two monoclonal anti-PEG Ig

  3. Generation, characterization and in vivo biological activity of two distinct monoclonal anti-PEG IgMs

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Yosuke; Shimizu, Taro; Mima, Yu [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan); Abu Lila, Amr S. [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan); Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Zagazig University, Sharqia Governorate, Zagazig 44519 (Egypt); Ishida, Tatsuhiro, E-mail: ishida@tokushima-u.ac.jp [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan); Kiwada, Hiroshi [Department of Pharmacokinetics and Biopharmaceutics, Subdivision of Biopharmaceutical Sciences, Institute of Health Biosciences, The University of Tokushima, 1-78-1, Sho-machi, Tokushima 770-8505 (Japan)

    2014-05-15

    PEGylation, the attachment of polyethylene glycol (PEG) to nanocarriers and proteins, is a widely accepted approach to improving the in vivo efficacy of the non-PEGylated products. However, both PEGylated liposomes and PEGylated proteins reportedly trigger the production of specific antibodies, mainly IgM, against the PEG moiety, which possibly leads to a reduction in safety and therapeutic efficacy of the PEGylated products. In the present study, two monoclonal anti-PEG IgMs — HIK-M09 via immunization with an intravenous injection of PEGylated liposomes (SLs) and HIK-M11 via immunization with a subcutaneous administration of PEGylated ovalbumin (PEG-OVA) were successfully generated. The generated IgMs showed efficient reactivity to mPEG{sub 2000} conjugated to 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine (DSPE), PEGylated liposome (SL) and PEG-OVA. It appears that HIK-M09 recognizes ethoxy (OCH{sub 2}CH{sub 2}) repeat units along with a terminal motif of PEG, while HIK-M11 recognizes only ethoxy repeat units of PEG. Such unique properties allow HIK-M09 to bind with dense PEG. In addition, their impact on the in vivo clearance of the PEGylated products was investigated. It was found that the generated ant-PEG IgMs induced a clearance of SL as they were intravenously administered with SL. Interestingly, the HIK-M11, generated by PEG-OVA, induced the clearance of both SL and PEG-OVA, while the HIK-M09, generated by SL, induced the clearance of SL only. We here revealed that the presence of serum anti-PEG IgM and the subsequent binding of anti-PEG IgM to the PEGylated products are not necessarily related to the enhanced clearance of the products. It appears that subsequent complement activation following anti-PEG IgM binding is the most important step in dictating the in vivo fate of PEGylated products. This study may have implications for the design, development and clinical application of PEGylated products and therapeutics. - Highlights: • Two monoclonal

  4. Development and in vivo evaluation of an oral insulin-PEG delivery system.

    Science.gov (United States)

    Calceti, P; Salmaso, S; Walker, G; Bernkop-Schnürch, A

    2004-07-01

    Insulin-monomethoxypoly(ethylene glycol) derivatives were obtained by preparation of mono- and di-terbutyl carbonate insulin derivatives, reaction of available protein amino groups with activated 750 Da PEG and, finally, amino group de-protection. This procedure allowed for obtaining high yield of insulin-1PEG and insulin-2PEG. In vivo studies carried out by subcutaneous injection into diabetic mice demonstrated that the two bioconjugates maintained the native biological activity. In vitro, PEGylation was found to enhance the hormone stability towards proteases. After 1 h incubation with elastase, native insulin, insulin-1PEG and insulin-2PEG undergo about 70, 30 and 10% degradation, respectively, while in the presence of pepsin protein degradation was 100, 70 and 50%, respectively. The attachment of low molecular weight PEG did not significantly (P >0.05) alter insulin permeation behavior across the intestinal mucosa. Insulin-1PEG was formulated into mucoadhesive tablets constituted by the thiolated polymer poly(acrylic acid)-cysteine. The therapeutic agent was sustained released from these tablets within 5 h. In vivo, by oral administration to diabetic mice, the glucose levels were found to decrease of about 40% since the third hour from administration and the biological activity was maintained up to 30 h. According to these results, the combination of PEGylated insulin with a thiolated polymer used as drug carrier matrix might be a promising strategy for oral insulin administration.

  5. The Effect of Tannins and Additional Peg on In Vitro Gas Production

    International Nuclear Information System (INIS)

    Irawan Sugoro

    2004-01-01

    Agro-wastes such as sugar cane straw are potential sources as feed. Sugar cane straw contains tannins, an anti-nutrient, which could effect feed quality. The effect of tannins by in vitro gas production was compared to maize straw which has low tannins. Tannin concentration was measured by using PEG which is labelled by 14 C. The result showed that the tannins concentration of sugar cane straw is 10.88 % dry matter. The others are digestibility of dry matter and organic matter, VFA, ammonia and pH. The gas production is 48.83 ml/500 mg after 24 h incubation. It is lower than the control i.e. 100.64 ml/500 mg. Additional PEG increase the gas production i.e. 30.5 %, because tannins is bounded by it. The concentration of ammonia, VFA, dry matter and organic matter digestibility on sugar cane straw with additional PEG is higher than without PEG, i.e 28.29 mg/100 ml, 15.56 nmol/100 ml, 52.18 % and 47.54 %. pH of sugar cane without PEG i.e. 6.62 is higher than additional PEG, i.e. 6.54. It could be concluded, tannins decrease of gas production, ammonia, VFA, dry matter, and organic matter digestibility and additional PEG increase gas production of sugar cane. (author)

  6. Characterization and improvement of PVAl/PVP/PEG hydrogels

    International Nuclear Information System (INIS)

    Oliveira, Maria Jose A.; Parra, Duclerc F.; Almeida, Monise F.; Lugao, Ademar B.

    2009-01-01

    The use of hydrogels matrices for particular drug release applications has been investigated with the synthesis of modified polymeric hydrogel of poly (vinyl alcohol) (PVAl), poly (N-vinyl-2-pyrrolidone) (PVP) and poly (ethylene glycol). They were processed using gamma radiation from Cobalt-60 source at 25 kGy dose. In this study it was compared the hydrogels reticulation for irradiation gamma O 2 and N 2 atmosphere. The characterization of the hydrogels was conducted and the toxicity was evaluated. The dried hydrogel was analyzed by differential scanning calorimetry (DSC), thermogravimetry (TGA), swelling and gel determinations. The membranes have no toxicity and gel content revealed the crosslinking degree. (author)

  7. Long-term stability of PEG-based antifouling surfaces in seawater

    DEFF Research Database (Denmark)

    Noguer, Albert Camós; Olsen, Stefan Møller; Hvilsted, Søren

    2016-01-01

    Poly(ethylene glycol) (PEG) is a hydrophilic polymer that has been extensively used in the biomedical and marine environment due to its antifouling properties. In the biomedical field, PEG has been successfully used to functionalize surfaces due to its resistance to cell and nonspecific protein...

  8. Drying and storage effects on poly(ethylene glycol) hydrogel mechanical properties and bioactivity.

    Science.gov (United States)

    Luong, P T; Browning, M B; Bixler, R S; Cosgriff-Hernandez, E

    2014-09-01

    Hydrogels based on poly(ethylene glycol) (PEG) are increasingly used in biomedical applications because of their ability to control cell-material interactions by tuning hydrogel physical and biological properties. Evaluation of stability after drying and storage are critical in creating an off-the-shelf biomaterial that functions in vivo according to original specifications. However, there has not been a study that systematically investigates the effects of different drying conditions on hydrogel compositional variables. In the first part of this study, PEG-diacrylate hydrogels underwent common processing procedures (vacuum-drying, lyophilizing, hydrating then vacuum-drying), and the effect of this processing on the mechanical properties and swelling ratios was measured. Significant changes in compressive modulus, tensile modulus, and swelling ratio only occurred for select processed hydrogels. No consistent trends were observed after processing for any of the formulations tested. The effect of storage conditions on cell adhesion and spreading on collagen- and streptococcal collagen-like protein (Scl2-2)-PEG-diacrylamide hydrogels was then evaluated to characterize bioactivity retention after storage. Dry storage conditions preserved bioactivity after 6 weeks of storage; whereas, storage in PBS significantly reduced bioactivity. This loss of bioactivity was attributed to ester hydrolysis of the protein linker, acrylate-PEG-N-hydroxysuccinimide. These studies demonstrate that these processing methods and dry storage conditions may be used to prepare bioactive PEG hydrogel scaffolds with recoverable functionality after storage. © 2013 Wiley Periodicals, Inc.

  9. Stabilization of sputtered gold and silver nanoparticles in PEG colloid solutions

    International Nuclear Information System (INIS)

    Slepička, P.; Elashnikov, R.; Ulbrich, P.; Staszek, M.; Kolská, Z.; Švorčík, V.

    2015-01-01

    In this study, a simple technique for preparation of colloid solution of metal nanoparticles in polyethylene glycol (PEG)/H 2 O is described. By this technique, stable colloidal metal solutions can be prepared ready for use without application of chemical reactions, stabilizers, or reducing agents. The nanoparticles are created by direct sputtering of metal into PEG. The influence of sputter conditions and the concentration of PEG/H 2 O on the properties of nanoparticles was studied. The nanoparticles were characterized by transmission electron microscopy, atomic absorption spectrometry, dynamic light scattering, and UV–Vis spectroscopy. UV–Vis spectra of gold nanoparticle solution exhibit localized surface plasmon resonance characteristic peaks located in the region 513–560 nm (PEG/H 2 O—1/1), 509–535 nm (PEG/H 2 O—1/9), and for silver nanoparticles in the region from 401 to 421 nm. Silver nanoparticles have a broader size distribution compared with gold ones. An appropriate choice of concentration, mixing, and deposition conditions allows preparing the stable solution of gold or silver nanoparticles

  10. Stabilization of sputtered gold and silver nanoparticles in PEG colloid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Slepička, P., E-mail: petr.slepicka@vscht.cz; Elashnikov, R. [University of Chemistry and Technology Prague, Department of Solid State Engineering (Czech Republic); Ulbrich, P. [University of Chemistry and Technology Prague, Department of Biochemistry and Microbiology (Czech Republic); Staszek, M. [University of Chemistry and Technology Prague, Department of Solid State Engineering (Czech Republic); Kolská, Z. [University of J. E. Purkyně, Faculty of Science (Czech Republic); Švorčík, V. [University of Chemistry and Technology Prague, Department of Solid State Engineering (Czech Republic)

    2015-01-15

    In this study, a simple technique for preparation of colloid solution of metal nanoparticles in polyethylene glycol (PEG)/H{sub 2}O is described. By this technique, stable colloidal metal solutions can be prepared ready for use without application of chemical reactions, stabilizers, or reducing agents. The nanoparticles are created by direct sputtering of metal into PEG. The influence of sputter conditions and the concentration of PEG/H{sub 2}O on the properties of nanoparticles was studied. The nanoparticles were characterized by transmission electron microscopy, atomic absorption spectrometry, dynamic light scattering, and UV–Vis spectroscopy. UV–Vis spectra of gold nanoparticle solution exhibit localized surface plasmon resonance characteristic peaks located in the region 513–560 nm (PEG/H{sub 2}O—1/1), 509–535 nm (PEG/H{sub 2}O—1/9), and for silver nanoparticles in the region from 401 to 421 nm. Silver nanoparticles have a broader size distribution compared with gold ones. An appropriate choice of concentration, mixing, and deposition conditions allows preparing the stable solution of gold or silver nanoparticles.

  11. Fabrication of poly(ethylene glycol) hydrogel micropatterns with osteoinductive growth factors and evaluation of the effects on osteoblast activity and function

    Energy Technology Data Exchange (ETDEWEB)

    Subramani, K [Institute for Nanoscale Science and Technology (INSAT), University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7AR (United Kingdom); Birch, M A [Institute for Nanoscale Science and Technology (INSAT), University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7AR (United Kingdom)

    2006-09-15

    The aims of this study were to fabricate poly(ethylene glycol) (PEG) hydrogel micropatterns on a biomaterial surface to guide osteoblast behaviour and to study how incorporating vascular endothelial growth factor (VEGF) within the adhered hydrogel influenced cell morphology. Standard photolithographic procedures or photopolymerization through a poly(dimethyl siloxane) (PDMS) mould were used to fabricate patterned PEG hydrogels on the surface of silanized silicon wafers. Hydrogel patterns were evaluated by light microscopy and surface profilometry. Rat osteoblasts were cultured on these surfaces and cell morphology investigated by fluorescence microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Release of protein trapped in the polymerized PEG was evaluated and VEGF-PEG surfaces were characterized for their ability to support cell growth. These studies show that photopolymerized PEG can be used to create anti-adhesive structures on the surface of silicon that completely control where cell interaction with the substrate takes place. Using conventional lithography, structures down to 50 {mu}m were routinely fabricated with the boundaries exhibiting sloping sides. Using the PDMS mould approach, structures were fabricated as small as 10 {mu}m and boundaries were very sharp and vertical. Osteoblasts exhibiting typical morphology only grew on the silicon wafer surface that was not coated with PEG. Adding BSA to the monomer solution showed that protein could be released from the hydrogel for up to 7 days in vitro. Incorporating VEGF in the hydrogel produced micropatterns that dramatically altered osteoblast behaviour. At boundaries with the VEGF-PEG hydrogel, there was striking formation of cellular processes and membrane ruffling indicative of a change in cell morphology. This study has explored the morphogenetic properties of VEGF and the applications of nano/microfabrication techniques for guided tissue (bone) regeneration in dental and

  12. Enhanced gelation of chitosan/β-sodium glycerophosphate thermosensitive hydrogel with sodium bicarbonate and biocompatibility evaluated.

    Science.gov (United States)

    Deng, Aipeng; Kang, Xi; Zhang, Jing; Yang, Yang; Yang, Shulin

    2017-09-01

    The application of chitosan/β-sodium glycerophosphate (β-GP) thermosensitive hydrogel has been limited by the relatively slow gelation, weak mechanical resistance and poor cytocompatibility. In this study, sodium hydrogen carbonate (NaHCO 3 ) was applied with β-GP as gel agents to produce high-strength hydrogel. The hydrogels prepared with high NaHCO 3 concentration or more gel agents showed shorter gelation time, better thermostability, drastically enhanced resistance in compression. Meanwhile, the hydrogels presented obvious porous structures and excellent biocompatibility to HUVEC and NIH 3T3 cultured in vitro with higher NaHCO 3 concentration and moderate concentration of β-GP. Overall, appropriate concentration of β-GP combined with NaHCO 3 can be a good gel regent to improve properties of chitosan thermosensitive hydrogels. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. PEG-related polymer resins as synthetic supports

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Combinatorial chemistry has become a significant part of the discovery and optimization process for novel drugs,affinity ligands,and catalysts.The polymeric supports play a key role in combinatory chemistry.Therefore,various kinds of functional polymer resins have been exploited as supports,reagents,and catalysts in organic synthesis.In comparison to the conventional Merrifield resins,the poly(ethylene glycol)(PEG)-related polymer resins have advantages including good compatibilities with polar solvents,good solvent absorbency and swelling properties.This review focuses primarily on the more recent work in the field of developing PEG-related polymer resins as supports for organic synthesis.

  14. Effects of PEG4000 template on sol-gel synthesis of porous cerium titanate photocatalyst

    Science.gov (United States)

    Zhang, Wenjie; Tao, Yingjie; Li, Chuanguo

    2018-04-01

    Porous cerium titanate was synthesized by sol-gel method, using polyethylene glycol (PEG4000) as template agent. Brannerite structured CeTi2O6 in monoclinic system is the major substance formed in the materials. Formation of CeO2 and rutile TiO2 depends on the amount of PEG4000. The addition of PEG4000 leads to production of fine particles in the samples, but it does not apparently affect the band gap energy. Pore volume of the cerium titanate sample continuously increases with rising PEG4000 amount. The sample obtained using 3.5 g PEG4000 has BET surface area of 16.2 m2/g and pore volume of 0.0232 cm3/g. The addition of PEG4000 can obviously promote photocatalytic activity of cerium titanate, which can be proven by both enhanced production of hydroxyl radical and ofloxacin degradation efficiency. As much as 95.2% of the initial ofloxacin molecules are removed from the solution after 50 min of photocatalytic degradation on the cerium titanate obtained using 3.5 g PEG4000, while only 48.4% ofloxacin is removed on cerium titanate obtained without PEG4000.

  15. PEG 3350 Administration Is Not Associated with Sustained Elevation of Glycol Levels.

    Science.gov (United States)

    Williams, Kent C; Rogers, Lynette K; Hill, Ivor; Barnard, John; Di Lorenzo, Carlo

    2018-04-01

    To determine whether trace amounts of ethylene glycol (EG), diethylene glycol (DEG), or triethylene glycol (TEG) in PEG 3350 are associated with increased blood levels of EG, DEG, or TEG in children receiving daily PEG 3350 therapy. Blood samples were drawn from 9 children who were being treated for constipation with PEG 3350 (6-12 years old) before and every 30 minutes for 3 hours after receiving 17 g of PEG 3350. PEG 3350, tap water, and blood samples from 18 age- and sex-matched controls also were analyzed. Baseline blood levels of EG and TEG did not differ between control and treated groups. DEG levels (median [IQR]) were lower in the PEG 3350 group (40.13 ng/mL [36.69, 63.94] vs 92.83 ng/mL [51.06, 128.93], P = .008). After PEG 3350 dose, levels of EG (390.51 ng/mL [326.06, 624.55]) and TEG (2.21 ng/mL [0, 4.5]) peaked at 90 minutes at 1032.81 ng/mL (826.84, 1486.13) (P = .009) and 35.17 ng/mL (15.81, 45.13) (P = .0005), respectively. DEG levels did not significantly change. Standard 17-g doses of PEG 3350 in 8 oz (237 mL) of water resulted in concentrations (mean ± SD) of EG, DEG, and TEG of 1.32 ± 0.23 µg/mL, 0.18 ± 0.03 µg/mL, and 0.12 ± 0.01 µg/mL, respectively. EG, DEG, and TEG levels in public water supply were 0.07 µg/mL, 0.21 µg/mL, and 0.02 µg/mL, respectively. Daily PEG 3350 therapy in children was not associated with sustained elevation of EG, DEG, or TEG blood levels over levels in matched controls. Although EG and TEG levels increased after a standard dose of PEG 3350, their peak values remained well below toxic levels. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A PEG Construction of LDPC Codes Based on the Betweenness Centrality Metric

    Directory of Open Access Journals (Sweden)

    BHURTAH-SEEWOOSUNGKUR, I.

    2016-05-01

    Full Text Available Progressive Edge Growth (PEG constructions are usually based on optimizing the distance metric by using various methods. In this work however, the distance metric is replaced by a different one, namely the betweenness centrality metric, which was shown to enhance routing performance in wireless mesh networks. A new type of PEG construction for Low-Density Parity-Check (LDPC codes is introduced based on the betweenness centrality metric borrowed from social networks terminology given that the bipartite graph describing the LDPC is analogous to a network of nodes. The algorithm is very efficient in filling edges on the bipartite graph by adding its connections in an edge-by-edge manner. The smallest graph size the new code could construct surpasses those obtained from a modified PEG algorithm - the RandPEG algorithm. To the best of the authors' knowledge, this paper produces the best regular LDPC column-weight two graphs. In addition, the technique proves to be competitive in terms of error-correcting performance. When compared to MacKay, PEG and other recent modified-PEG codes, the algorithm gives better performance over high SNR due to its particular edge and local graph properties.

  17. Germination Behaviour of Lawsonia inermis L. as Influenced by Polyethylene Glycol (PEG

    Directory of Open Access Journals (Sweden)

    Enneb Hanen

    2016-11-01

    Full Text Available Tunisian Flora is well known for its richness and diversity of medicinal plants such as henna plant (Lawsonia inermis L. a flowering plant belongs to the family of Lyteraceae, distributed in dry tropical and subtropical zones including North Africa. This plant pertains to continental oases where water shortage, constitute the essential limiting factor of agricultural production. The present study was carried out to evaluate the impact of water stress on the germination of the henna plant (Lawsonia inermis L.. Seeds were germinated under stress of aqueous Polyethylene Glycol (PEG solutions blended to create water potentials of 0, -0.2, -0.4, -0.6, - 0.8 and -1 MPa. Results showed that seeds germinated in PEG solutions exhibited significantly lower cumulative germination rate (CGR than control especially when water potential fell below -0.6 MPa. Mean germination time (MGT was delayed by increasing PEG concentrations, while germination stress tolerance index (GSTI was decreased with the increase in PEG concentrations. The highest percentage of GSTI in stressed condition was 84.13% for PEG (-0.2MPa whereas, the lowest value was 8.37% for PEG (-1MPa.

  18. Antibiofouling hybrid dendritic Boltorn/star PEG thiol-ene cross-linked networks.

    Science.gov (United States)

    Bartels, Jeremy W; Imbesi, Philip M; Finlay, John A; Fidge, Christopher; Ma, Jun; Seppala, Jonathan E; Nystrom, Andreas M; Mackay, Michael E; Callow, James A; Callow, Maureen E; Wooley, Karen L

    2011-06-01

    A series of thiol-ene generated amphiphilic cross-linked networks was prepared by reaction of alkene-modified Boltorn polyesters (Boltorn-ene) with varying weight percent of 4-armed poly(ethylene glycol) (PEG) tetrathiol (0-25 wt%) and varying equivalents of pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) (0-64 wt%). These materials were designed to present complex surface topographies and morphologies, with heterogeneity of surface composition and properties and robust mechanical properties, to serve as nontoxic antibiofouling coatings that are amenable to large-scale production for application in the marine environment. Therefore, a two-dimensional matrix of materials compositions was prepared to study the physical and mechanical properties, over which the compositions spanned from 0 to 25 wt% PEG tetrathiol and 0-64 wt% PETMP (the overall thiol/alkene (SH/ene) ratios ranged from 0.00 to 1.00 equiv), with both cross-linker weight percentages calculated with respect to the weight of Boltorn-ene. The Boltorn-ene components were prepared through the esterification of commercially available Boltorn H30 with 3-butenoic acid. The subsequent cross-linking of the Boltorn-PEG-PETMP films was monitored using IR spectroscopy, where it was found that near-complete consumption of both thiol and alkene groups occurred when the stoichiometry was ca. 48 wt% PETMP (0.75 equiv SH/ene, independent of PEG amount). The thermal properties of the films showed an increase in T(g) with an increase in 4-armed PEG-tetrathiol wt%, regardless of the PETMP concentration. Investigation of the bulk mechanical properties in dry and wet states found that the Young's modulus was the greatest at 48 wt% PETMP (0.75 equiv of SH/ene). The ultimate tensile strength increased when PETMP was constant and the PEG concentration was increased. The Young's modulus was slightly lower for wet films at constant PEG or constant PETMP amounts, than for the dry samples. The nanoscopic surface features were

  19. Sensitive and rapid detection of anti-PEG in blood using surface plasmon resonance sensor (Conference Presentation)

    Science.gov (United States)

    Sun, Fang; Jiang, Shaoyi; Yu, Qiuming

    2016-03-01

    Polyethylene glycol (PEG) is widely used to modify many therapeutic proteins and nanoparticles to reduce their immunogenicity and to improve their pharmacokinetic and therapeutic properties. It is generally accepted that PEG is non-immunogenic and non-antigenic. However, an emerging of literature and studies shows that the immune system can generate specific antibodies binding PEG. These anti-PEG antibodies not only correlate with adverse reactions appeared after patient infusions, but are also found to be the reason for therapeutic efficacy loss during chronical administrations. In addition, because of constant exposure to PEG in daily consumer products including detergents, processed food and cosmetics, a substantial proportion of the population has likely developed anti-PEG immunity. Thus a method to quickly and accurately measure the anti-PEG antibody level is desired. Nevertheless, the gold standard to detect anti-PEG antibodies is ELISA, which is costly and time-consuming especially for quantification. Herein, we demonstrated the anti-PEG measurement in blood serum using surface plasmon resonance (SPR) sensor. Several PEG-based surface functionalization on SPR sensor chip were studied in terms of protein resistance and the limit of detection (LOD) of anti-PEG. The quantitative detection can be achieved in less than 30 min with LOD comparable to ELISA. Furthermore, the IgG and IgM of anti-PEG can be differentiated by following the secondary antibody.

  20. Inhibition of HeLa cell growth by doxorubicin-loaded and tuftsin-conjugated arginate-PEG microparticles

    Directory of Open Access Journals (Sweden)

    Tianmu Hu

    2018-03-01

    Full Text Available In order to improve the release pattern of chemotherapy drug and reduce the possibility of drug resistance, poly(ethylene glycol amine (PEG-modified alginate microparticles (ALG-PEG MPs were developed then two different mechanisms were employed to load doxorubicin (Dox: 1 forming Dox/ALG-PEG complex by electrostatic attractions between unsaturated functional groups in Dox and ALG-PEG; 2 forming Dox-ALG-PEG complex through EDC-reaction between the amino and carboxyl groups in Dox and ALG, respectively. Additionally, tuftsin (TFT, a natural immunomodulation peptide, was conjugated to MPs in order to enhance the efficiency of cellular uptake. It was found that the Dox-ALG-PEG-TFT MPs exhibited a significantly slower release of Dox than Dox/ALG-PEG-TFT MPs in neutral medium, suggesting the role of covalent bonding in prolonging Dox retention. Besides, the release of Dox from these MPs was pH-sensitive, and the release rate was observably increased at pH 6.5 compared to the case at pH 7.4. Compared with Dox/ALG-PEG MPs and Dox-ALG-PEG MPs, their counterparts further conjugated with TFT more efficiently inhibited the growth of HeLa cells over a period of 48 h, implying the effectiveness of TFT in enhancing cellular uptake of MPs. Over a period of 48 h, Dox-ALG-PEG-TFT MPs inhibited the growth of HeLa cells less efficiently than Dox/ALG-PEG-TFT MPs but the difference was not significant (p > 0.05. In consideration of the prolonged and sustained release of Dox, Dox-ALG-PEG-TFT MPs possess the advantages for long-term treatment.

  1. Keratocyte behavior in three-dimensional photopolymerizable poly(ethylene glycol) hydrogels

    Science.gov (United States)

    Thibault, Richard; Ambrose, Winnette McIntosh; Schein, Oliver D.; Chakravarti, Shukti; Elisseeff, Jennifer

    2015-01-01

    The goal of this study was to evaluate three-dimensional (3-D) poly(ethylene glycol) (PEG) hydrogels as a culture system for studying corneal keratocytes. Bovine keratocytes were subcultured in DMEM/F-12 containing 10% fetal bovine serum (FBS) through passage 5. Primary keratocytes (P0) and corneal fibroblasts from passages 1 (P1) and 3 (P3) were photoencapsulated at various cell concentrations in PEG hydrogels via brief exposure to light. Additional hydrogels contained adhesive YRGDS and nonadhesive YRDGS peptides. Hydrogel constructs were cultured in DMEM/F-12 with 10% FBS for 2 and 4 weeks. Cell viability was assessed by DNA quantification and vital staining. Biglycan, type I collagen, type III collagen, keratocan and lumican expression were determined by reverse transcriptase–polymerase chain reaction. Deposition of type I collagen, type III collagen and keratan sulfate (KS)-containing matrix components was visualized using confocal microscopy. Keratocytes in a monolayer lost their stellate morphology and keratocan expression, displayed elongated cell bodies, and up-regulated biglycan, type I collagen and type III collagen characteristic of corneal fibroblasts. Encapsulated keratocytes remained viable for 4 weeks with spherical morphologies. Hydrogels supported production of KS, type I collagen and type III collagen matrix components. PEG-based hydrogels can support keratocyte viability and matrix production. 3-D hydrogel culture can stabilize but not restore the keratocyte phenotype. This novel application of PEG hydrogels has potential use in the study of corneal keratocytes in a 3-D environment. PMID:18567550

  2. Incorporation of fluconazole in copolymer PMMA-g-PEG derivatives; Incorporacao de fluconazol em ineditos derivados do copolimero PMMA-g-PEG

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, B.M.; Santos, V.M.R. dos; Novack, K.M.; Lopes, S.A., E-mail: vmrebello@yahoo.com.br [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)

    2014-07-01

    The graft copolymer PMMA-g-PEG went through chemical transformations in its chain through acetylation, halogenation, methylation and esterification followed by hydrolysis reactions. Subsequently, the copolymer PMMA-g-PEG derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Derivatives copolymers were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) after incorporation in order to evaluate their effectiveness. The efficiency of incorporation was observed and it was also verified that the complexity of polymer chain influence in the incorporated fluconazole content. (author)

  3. Acute toxicity and pharmacokinetics of 13 nm-sized PEG-coated gold nanoparticles

    International Nuclear Information System (INIS)

    Cho, Wan-Seob; Cho, Minjung; Jeong, Jinyoung; Choi, Mina; Cho, Hea-Young; Han, Beom Seok; Kim, Sheen Hee; Kim, Hyoung Ook; Lim, Yong Taik; Chung, Bong Hyun; Jeong, Jayoung

    2009-01-01

    In general, gold nanoparticles are recognized as being as nontoxic. Still, there have been some reports on their toxicity, which has been shown to depend on the physical dimension, surface chemistry, and shape of the nanoparticles. In this study, we carry out an in vivo toxicity study using 13 nm-sized gold nanoparticles coated with PEG (MW 5000). In our findings the 13 nm sized PEG-coated gold nanoparticles were seen to induce acute inflammation and apoptosis in the liver. These nanoparticles were found to accumulate in the liver and spleen for up to 7 days after injection and to have long blood circulation times. In addition, transmission electron microscopy showed that numerous cytoplasmic vesicles and lysosomes of liver Kupffer cells and spleen macrophages contained the PEG-coated gold nanoparticles. These findings of toxicity and kinetics of PEG-coated gold nanoparticles may have important clinical implications regarding the safety issue as PEG-coated gold nanoparticles are widely used in biomedical applications

  4. Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve.

    Science.gov (United States)

    Huang, Lanfeng; Li, Rui; Liu, Wanguo; Dai, Jin; Du, Zhenwu; Wang, Xiaonan; Ma, Jianchao; Zhao, Jinsong

    2014-07-15

    Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, but cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhesion stage. Moreover, seeded cells were distributed throughout the material.

  5. Coaxial electro-spun PEG/PA6 composite fibers: Fabrication and characterization

    International Nuclear Information System (INIS)

    Babapoor, Aziz; Karimi, Gholamreza; Golestaneh, Seyyed Iman; Mezjin, Mehdi Ahmadi

    2017-01-01

    Highlights: • Core-shell PCM nanofibers are fabricated by coaxial electrospinning. • PEG1000 (core) and PA6 (shell) are used to fabricate nanofibers. • The peak temperature is increased by raising the PEG concentration. • The shell structure can prevent PEG leakage at high temperatures. - Abstract: Energy storage systems have been recognized as one of the most important technologies for conservation and utilization of renewable energy sources. In this study, core-shell phase change material (PCM) nanofibers were fabricated by using coaxial electrospinning of polyethylene glycol (PEG1000) as the core material (i.e., PCM) and polyamide 6 (PA6) as the shell (supporting) material. The effects of inner core solution flow rate and PEG content on the morphology, structure, and phase change behavior of the produced composite fibers were studied thoroughly by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The experimental results indicated that by increasing the flow rate of the core solution, slightly thicker fibers can be produced, and the onset temperature of melting is reduced. Also, as the PEG concentration rises, the peak temperature increases and higher amounts of latent heat enthalpy are achieved. The results indicate that the fabricated core-shell structure has almost resolved the leakage instability normally associated with other types of PCM fibers and hence, has the potential to improve thermal storage capacity.

  6. Complete regression of xenograft tumors using biodegradable mPEG-PLA-SN38 block copolymer micelles.

    Science.gov (United States)

    Lu, Lu; Zheng, Yan; Weng, Shuqiang; Zhu, Wenwei; Chen, Jinhong; Zhang, Xiaomin; Lee, Robert J; Yu, Bo; Jia, Huliang; Qin, Lunxiu

    2016-06-01

    7-Ethyl-10-hydroxy-comptothecin (SN38) is an active metabolite of irinotecan (CPT-11) and the clinical application of SN38 is limited by its hydrophobicity and instability. To address these issues, a series of novel amphiphilic mPEG-PLA-SN38-conjugates were synthesized by linking SN38 to mPEG-PLA-SA, and they could form micelles by self-assembly. The effects of mPEG-PLA composition were studied in vitro and in vivo. The mean diameters of mPEG2K-PLA-SN38 micelles and mPEG4K-PLA-SN38 micelles were 10-20nm and 120nm, respectively, and mPEG2K-PLA-SN38 micelles showed greater antitumor efficacy than mPEG4K-PLA-SN38 micelles both in vitro and in vivo. These data suggest that the lengths of mPEG and PLA chains had a major impact on the physicochemical characteristics and antitumor activity of SN38-conjugate micelles. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Radiation synthesis and characterization of thermo-sensitive PNIPA/clay hydrogels

    International Nuclear Information System (INIS)

    Song Hongyan; He Suqin; Liu Wentao; Zhu Chengshen; Yang Mingcheng

    2007-01-01

    In this work, the thermo-sensitive hydrogels of PNIPA/Clay were synthesized by 60 Co-γ rays irradiation. The effects of organically modified clay and Na + clay, clay content, and dispersing condition on swelling behavior of PNIPA/clay hydrogels were investigated. The results showed that the equilibrium swelling ratio (SR) of the PNIPA/clay hydrogels is better than PNIPA, and the SR of PNIPA/organically modified clay hydrogels is the highest. With clay content increases, the SR of hydrogels became better. The deswelling behavior of hydrogel was improved, the deswelling ratio of the hydrogel with organically modified clay is highest, and ratio of losing water is 83%, while PNIPA is about 50%. The compressive properties of hydrogel composites were also examined. The results showed that the compressive properties of the PNIPA/clay hydrogels were improved distinctly than that of the conventional hydrogels without clay. And with increasing of clay content, the compressive properties of hydrogel composites improve rapidly. When the content of clay is 15%, the maximum compression force of the PNIPA/clay hydrogel is 5.28N, which is 14 times of PNIPA hydrogel and compression strength is 2.5 times. (authors)

  8. Injectable dual redox responsive diselenide-containing poly(ethylene glycol) hydrogel.

    Science.gov (United States)

    Gong, Chu; Shan, Meng; Li, Bingqiang; Wu, Guolin

    2017-09-01

    An injectable dual redox responsive diselenide-containing poly(ethylene glycol) (PEG) hydrogel was successfully developed by combining the conceptions of injectable hydrogels and dual redox responsive diselenides. In the first step, four-armed PEG was modified with N-hydroxysuccinimide (NHS)-activated esters and thereafter, crosslinked by selenocystamine crosslinkers to form injectable hydrogels via the rapid reaction between NHS-activated esters and amino groups. The cross-sectional morphology, mechanical properties, and crosslinking modes of hydrogels were well characterized via scanning electron microscope (SEM), rheological measurements, and Fourier transform infrared spectra, respectively. In addition, the oxidation- and reduction-responsive degradation behaviors of hydrogels were observed and analyzed. The model drug, rhodamine B, was encapsulated in the hydrogel. The drug-loaded hydrogel exhibited a dual redox responsive release profile, which was consistent with the degradation experiments. The results of all experiments indicated that the formulated injectable dual redox responsive diselenide-containing PEG hydrogel can have potential applications in various biomedical fields such as drug delivery and stimuli-responsive drug release. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2451-2460, 2017. © 2017 Wiley Periodicals, Inc.

  9. Automated real time peg and tool detection for the FLS trainer box.

    Science.gov (United States)

    Nemani, Arun; Sankaranarayanan, Ganesh

    2012-01-01

    This study proposes a method that effectively tracks trocar tool and peg positions in real time to allow real time assessment of the peg transfer task of the Fundamentals of Laparoscopic Surgery (FLS). By utilizing custom code along with OpenCV libraries, tool and peg positions can be accurately tracked without altering the original setup conditions of the FLS trainer box. This is achieved via a series of image filtration sequences, thresholding functions, and Haar training methods.

  10. The effect of pH on bromelain partition from Ananas comosus by PEG4000/phosphate ATPS

    Directory of Open Access Journals (Sweden)

    Juliana Ferrari Ferreira

    2011-02-01

    Full Text Available In this work, the thermodynamic equilibrium and applying of PEG4000/Phosphate ATPS on the purification of bromelain extracted from pineapple was studied. A rigorous study of the equilibrium curves and tie-line length from PEG4000/phosphate ATPS were done for the pH 6-11 at 25ºC. Results showed that there was augment in the PEG and salt contents with the high pH value from PEG4000/Phosphate ATPS and two-phase formation needed only increasing the PEG content. Two tie-line length at pH 11 from PEG4000/Phosphate ATPS were optimal condition for bromelain purification, one on composition of 14% PEG and 13% salt and other at 12.6% PEG and 12.2% salt, while a 25-62 folds of enzyme was found. SDS-PAGE electrophoreses had one band only, which showed that bromelain was purified. Optimum conditions of bromelain use were found at pH 7 and between 30-40ºC.

  11. Poly(ethylene glycol)-based thiol-ene hydrogel coatings: curing chemistry, aqueous stability, and potential marine antifouling applications

    NARCIS (Netherlands)

    Lundberg, P.; Bruin, A.; Klijnstra, J.W.; Nyström, A.M.; Johansson, M.; Malkoch, M.; Hult, A.

    2010-01-01

    Photocured thiol-ene hydrogel coatings based on poly(ethylene glycol) (PEG) were investigated for marine antifouling purposes. By varying the PEG length, vinylic end-group, and thiol cross-linker, a library of hydrogel coatings with different structural composition was efficiently accomplished, with

  12. Synthesis and characterisation of PEG modified chitosan nanocapsules loaded with thymoquinone.

    Science.gov (United States)

    Vignesh Kumar, Suresh Kumar; Renuka Devi, Ponnuswamy; Harish, Saru; Hemananthan, Eswaran

    2017-02-01

    Thymoquinone (TQ), a major bioactive compound of Nigella sativa seeds has several therapeutic properties. The main drawback in bringing TQ to therapeutic application is that it has poor stability and bioavailability. Hence a suitable carrier is essential for TQ delivery. Recent studies indicate biodegradable polymers are potentially good carriers of bioactive compounds. In this study, polyethylene glycol (PEG) modified chitosan (Cs) nanocapsules were developed as a carrier for TQ. Aqueous soluble low molecular weight Cs and PEG was selected among different biodegradable polymers based on their biocompatibility and efficacy as a carrier. Optimisation of synthesis of nanocapsules was done based on particle size, PDI, encapsulation efficiency and process yield. A positive zeta potential value of +48 mV, indicating good stability was observed. Scanning electron microscope and atomic-force microscopy analysis revealed spherical shaped and smooth surfaced nanocapsules with size between 100 to 300 nm. The molecular dispersion of the TQ in Cs PEG nanocapsules was studied using X-ray powder diffraction. The Fourier transform infrared spectrum of optimised nanocapsule exhibited functional groups of both polymer and drug, confirming the presence of Cs, PEG and TQ. In vitro drug release studies showed that PEG modified Cs nanocapsules loaded with TQ had a slow and sustained release.

  13. Electrically conductive gold nanoparticle-chitosan thermosensitive hydrogels for cardiac tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Baei, Payam [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of); Cardiovascular Engineering Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Jalili-Firoozinezhad, Sasan [Department of Biomedicine and Surgery, University Hospital Basel, University of Basel, Hebelstrasse 20, CH-4031 Basel (Switzerland); Department of Bioengineeringand IBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Rajabi-Zeleti, Sareh [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of); Tafazzoli-Shadpour, Mohammad [Cardiovascular Engineering Laboratory, Faculty of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Baharvand, Hossein, E-mail: Baharvand@royaninstitute.org [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of); Department of Developmental Biology, University of Science and Culture, ACECR, Tehran (Iran, Islamic Republic of); Aghdami, Nasser, E-mail: Nasser.Aghdami@royaninstitute.org [Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran (Iran, Islamic Republic of)

    2016-06-01

    Injectable hydrogels that resemble electromechanical properties of the myocardium are crucial for cardiac tissue engineering prospects. We have developed a facile approach that uses chitosan (CS) to generate a thermosensitive conductive hydrogel with a highly porous network of interconnected pores. Gold nanoparticles (GNPs) were evenly dispersed throughout the CS matrix in order to provide electrical cues. The gelation response and electrical conductivity of the hydrogel were controlled by different concentrations of GNPs. The CS-GNP hydrogels were seeded with mesenchymal stem cells (MSCs) and cultivated for up to 14 days in the absence of electrical stimulations. CS-GNP scaffolds supported viability, metabolism, migration and proliferation of MSCs along with the development of uniform cellular constructs. Immunohistochemistry for early and mature cardiac markers showed enhanced cardiomyogenic differentiation of MSCs within the CS-GNP compared to the CS matrix alone. The results of this study demonstrate that incorporation of nanoscale electro-conductive GNPs into CS hydrogels enhances the properties of myocardial constructs. These constructs could find utilization for regeneration of other electroactive tissues. - Highlights: • Thermosensitive electro-conductive hydrogels were prepared from CS and GNPs. • Gelation time and conductivity were tuned by varying concentration of GNPs. • CS-2GNP with gelation time of 25.7 min and conductivity of 0.13 S·m{sup −1} was selected for in vitro studies. • CS-2GNP supported active metabolism, migration and proliferation of MSCs. • Expression of cardiac markers increased about two-fold in CS-2GNP compared to CS.

  14. Electrically conductive gold nanoparticle-chitosan thermosensitive hydrogels for cardiac tissue engineering

    International Nuclear Information System (INIS)

    Baei, Payam; Jalili-Firoozinezhad, Sasan; Rajabi-Zeleti, Sareh; Tafazzoli-Shadpour, Mohammad; Baharvand, Hossein; Aghdami, Nasser

    2016-01-01

    Injectable hydrogels that resemble electromechanical properties of the myocardium are crucial for cardiac tissue engineering prospects. We have developed a facile approach that uses chitosan (CS) to generate a thermosensitive conductive hydrogel with a highly porous network of interconnected pores. Gold nanoparticles (GNPs) were evenly dispersed throughout the CS matrix in order to provide electrical cues. The gelation response and electrical conductivity of the hydrogel were controlled by different concentrations of GNPs. The CS-GNP hydrogels were seeded with mesenchymal stem cells (MSCs) and cultivated for up to 14 days in the absence of electrical stimulations. CS-GNP scaffolds supported viability, metabolism, migration and proliferation of MSCs along with the development of uniform cellular constructs. Immunohistochemistry for early and mature cardiac markers showed enhanced cardiomyogenic differentiation of MSCs within the CS-GNP compared to the CS matrix alone. The results of this study demonstrate that incorporation of nanoscale electro-conductive GNPs into CS hydrogels enhances the properties of myocardial constructs. These constructs could find utilization for regeneration of other electroactive tissues. - Highlights: • Thermosensitive electro-conductive hydrogels were prepared from CS and GNPs. • Gelation time and conductivity were tuned by varying concentration of GNPs. • CS-2GNP with gelation time of 25.7 min and conductivity of 0.13 S·m"−"1 was selected for in vitro studies. • CS-2GNP supported active metabolism, migration and proliferation of MSCs. • Expression of cardiac markers increased about two-fold in CS-2GNP compared to CS.

  15. Treatment with mPEG-SPA improves the survival of corneal grafts in rats by immune camouflage.

    Science.gov (United States)

    Wang, Shuangyong; Li, Liangliang; Liu, Ying; Li, Chaoyang; Zhang, Min; Wang, Bowen; Huang, Zheqian; Gao, Xinbo; Wang, Zhichong

    2015-03-01

    We investigated the immune camouflage effects of methoxy polyethylene glycol succinimidyl propionate (mPEG-SPA) on corneal antigens and explored a novel approach for reducing corneal antigenicity, thereby decreasing corneal graft rejection. Importantly, this approach did not alter normal local immunity. Corneal grafts were treated with mPEG-SPA 5KD or 20KD (3% W/V), which could shield major histocompatibility antigen class I molecules (RT1-A) of corneal grafts. Skin grafts of Wistar rats were transplanted to SD rats. Then the splenic lymphocytes were isolated from SD rats. Subsequently, the lymphocytes were co-cultured with autologous corneal grafts or untreated corneal grafts and PEGylated grafts treated with mPEG-SPA 5KD or 20KD obtained from the counterpart skin donors, which were used as autologous control, allogeneic control, mPEG-SPA 5KD group and mPEG-SPA 20KD group, respectively. Lymphocyte proliferation was lower in mPEG-SPA 5KD group and mPEG-SPA 20KD group than in the allogeneic control. SD rats with corneal neovascularisation were used as recipients for high-risk corneal transplantation and were randomly divided into four groups: autologous control, allogeneic control, mPEG-SPA 5KD group and mPEG-SPA 20KD group. The recipients received corneal grafts from Wistar rats. Corneal graft survival was prolonged and graft rejection was reduced in the mPEG-SPA 5KD group and the mPEG-SPA 20KD group compared to the allogeneic control. Thus, we think that mPEG-SPA could immunologically camouflage corneal antigens to prolong corneal grafts survival in high-risk transplantation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. PEG/CaFe{sub 2}O{sub 4} nanocomposite: Structural, morphological, magnetic and thermal analyses

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, Lavanya, E-mail: lavanshya@yahoo.co.in; Verma, Narendra K., E-mail: nkverma@thapar.edu

    2013-10-15

    The coating of Polyethylene Glycol (PEG) on calcium ferrite (CaFe{sub 2}O{sub 4}) nanoparticles has been reported in the present study. The X-ray diffraction pattern revealed the formation of orthorhombic structure of bare CaFe{sub 2}O{sub 4} nanoparticles, which was also retained after the PEG coating, along with additional characteristic peaks of PEG at 19° and 23°. The rings of CaFe{sub 2}O{sub 4} nanoparticles were identified by the selected area electron diffraction pattern. The characteristic bands of PEG as observed in its Fourier transform infrared spectrum were also present in PEG coated CaFe{sub 2}O{sub 4} nanoparticles, hence confirming its presence. In the thermal gravimetric studies, the complete thermal decomposition of PEG occurred in a one step process, but in case of PEG coated CaFe{sub 2}O{sub 4} nanoparticles, the decomposition took place at a higher temperature owing to the formation of covalent bonds of PEG with CaFe{sub 2}O{sub 4} nanoparticles. The presence of PEG on CaFe{sub 2}O{sub 4} nanoparticles, spherical formation of PEG coated CaFe{sub 2}O{sub 4} nanoparticles and reduced agglomeration in the CaFe{sub 2}O{sub 4} nanoparticles were revealed by high resolution transmission electron microscope, transmission electron microscope and scanning electron microscope studies, respectively. In vibrating sample magnetometer analysis, both bare as well as coated CaFe{sub 2}O{sub 4} nanoparticles exhibited superparamagnetic behavior. However, a drop in the magnetic saturation value was observed from 36.76 emu/g for CaFe{sub 2}O{sub 4} nanoparticles to 6.74 emu/g for PEG coated CaFe{sub 2}O{sub 4} nanoparticles, due to the formation of magnetically dead layer of PEG. In ZFC and FC analyses, superparamagnetic behavior with blocking temperature for bare and coated nanoparticles has been observed at ∼40 K and ∼60 K, respectively. The increase in the blocking temperature is attributed to the increase in the particle size after PEG coating.

  17. Effect of PEG-6000 Imposed Water Deficit on Chlorophyll Metabolism in Maize Leaves

    Directory of Open Access Journals (Sweden)

    Rekha Gadre

    2013-08-01

    Full Text Available Drought stress is one of the major abiotic constraint limiting plant growth and productivity world wide. The current study was undertaken with the aim to investigate the effect of water deficit imposed by PEG-6000, on chlorophyll metabolism in maize leaves to work out the mechanistic details. Leaf segments prepared from primary leaves of etiolated maize seedlings were treated with varying concentrations of polyethylene glycol-6000 (PEG-6000; w/v- 5%, 10%, 20%, 30% in continuous light of intensity 40 Wm-2 at 26±2 °C for 24 h in light chamber. The results demonstrate a concentration dependent decline in chlorophyll content with increasing concentration of polyethylene glycol-6000 (PEG-6000. Reduction in chlorophyll ‘a’ level was to a greater extent than the chlorophyll ‘b’. The RNA content decreased in a concentration dependent manner with PEG, however, proline content increased significantly. Relative water content decreased significantly with the supply of 30% PEG only. A substantial decrease in chlorophyll synthesis due to significant reduction in ALA content and ALAD activity, with no change in chlorophyllase activity with the supply of PEG suggests that water deficit affects chlorophyll formation rather than its degradation.

  18. A fundamental research on T3 radioimmunoassay by polyethylene glycol (PEG) method

    International Nuclear Information System (INIS)

    Takahashi, Tadashige; Hayakawa, Susumu; Takagi, Atsushi; Sugisawa, Yoshihiko; Kurata, Kunio

    1976-01-01

    Since Chopra, et al. produced an antibody of triiodothyronine (T 3 ), measurement of serum T 3 by radioimmunoassay has been widely used as a clinical test. However, the dextran coated charcoal (DCC) method which is most commonly used for B/F separation requires strict control of incubation temperature and time. The authors reduced this disadvantage by using polyethylene glycol (PEG) instead of DCC for B/F separation. Crossreactivities of the antibody used with thyroxine, monoiodothyrosine and diiodotyrosine are less than 0.06% which is considered to be satisfactory in comparison with those previously reported. The recovery ratios of added T 3 were between 92.4 - 105.9% and that reflected T 3 concentration well. The dilution test showed good linearity. Correlation of T 3 values measured by DCC method and PEG method in 26 sera was good (r=0.99), and linear regression function was y=0.89x + 0.30 (y: PEG method and x: DCC method). No significant differences were observed in the results obtained by 2 hr incubation at 20 - 35 0 C and 24 hr incubation at 4 0 C. As for the volume of PEG solution, 1.0 ml was most suitable. Samples should be kept at 4 0 C when centrifugation is impossible within 30 min after addition of PEG. Also in various conditions of centrifugation, the authors obtained almost same results. As described above, the authors conquered the problem involved in the DCC method, and also simplified the assay procedure by using the PEG method for B/F separation. PEG method is considered to be the methods of choice for clinical routine test for serum T 3 levels (Evans, J.)

  19. A mixed ruthenium polypyridyl complex containing a PEG-bipyridine macroligand

    Energy Technology Data Exchange (ETDEWEB)

    Marin, Veronica; Holder, Elisabeth; Meier, Michael A.R.; Hoogenboom, Richard; Schubert, Ulrich S. [Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute (DPI), P. O. Box 513, 5600 MB Eindhoven (Netherlands)

    2004-04-06

    An amino-functionalized bipyridine ligand was prepared in order to serve as a bridging unit to an activated low-molecular-weight monomethyl ether of poly(ethylene glycol) (PEG). Coordination of a ruthenium(II) phenantroline precursor onto the formed PEG-containing bipyridine ligand yielded a metal-containing polymer which shows interesting properties for solar cell applications. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  20. Improving dielectric permittivity by incorporating PDMS-PEG block copolymer into PDMS network

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    Polydimethylsiloxane (PDMS) based elastomers are well-known to actuate with large strain mainly due to their low modulus and their non-conducting nature. On the other hand, polyethyleneglycols(PEG) are not stretchable but they have high permittivity and are conductive. Combination of the two...... polymers as a block copolymer depicts a possibility for substantial improvement of properties such as high permittivity and non-conductivity – if carefully designed. The objective is to synthesize PDMS-PEG multiblock copolymer assembling into different morphologies1 such as lamellar,cylinder, gyroid...... and spheres based on variation of volume fractions of PDMS and PEG. The synthesisis amended from Klasner et al.2 and Jukarainen et al.3 Variation in the ratio between the two constituents introduces distinctive properties in terms of dielectric permittivity and rheological behaviour. PDMS-PEG multiblock...

  1. Current status of percutaneous endoscopic gastrostomy (PEG) in a general hospital in Japan: a cross-sectional study

    Science.gov (United States)

    Kusano, Chika; Yamada, Nobuo; Kikuchi, Kenji; Hashimoto, Masaji; Gotoda, Takuji

    2016-01-01

    Background: There has been debate over the indications for percutaneous endoscopic gastrostomy (PEG) in recent years in Japan. In addition, the level of satisfaction of patients and patient’s family after PEG remains unclear. The aim of this study was to investigate the current status of PEG and the level of satisfaction of patients and patients’ families after PEG in Japan. Methods: We reviewed the existing data of all patients who underwent PEG tube insertion at Yuri Kumiai General Hospital (Akita, Japan) between February 2000 and December 2010. We examined the following points: underlying diseases requiring PEG, levels of consciousness, and performance status. We also sent a questionnaire to the patients and patient’s families to ask about their satisfaction with and thoughts about PEG. Results: The data of 545 patients who underwent PEG were reviewed. There were 295 men and 250 women, with a mean age of 77.2 ± 11.4 years. PEG was indicated most frequently for cerebrovascular disorders (48.2%, 239/545). There were 515 (94.4%, 515/545) patients showing consciousness disturbance and 444 (81.5%, 444/545) bedridden patients. The questionnaire was answered by one patient himself and 316 patients’ families. When asked, “Was performing PEG a good decision?”, 57.5% (182/316) of the patients’ families answered yes. Meanwhile, when patients’ family members were asked if they would wish to undergo PEG if they were in the same condition as the patient, 28.4% (90/316) answered yes, whereas 55.3% (175/316) answered no. Conclusions: Few patients were able to make their own decision about PEG tube placement because of consciousness disturbance. As a result, many family members of the patients did not want to experience PEG for themselves. Future studies should be performed to clarify the quality of life and ethical aspects associated with PEG. PMID:27313796

  2. Digital Drug Dosing: Dosing in Drug Assays by Light-Defined Volumes of Hydrogels with Embedded Drug-Loaded Nanoparticles

    DEFF Research Database (Denmark)

    Faralli, Adele; Melander, Fredrik; Larsen, Esben Kjær Unmack

    2014-01-01

    Polyethylene glycol (PEG)-based hydrogels are widely used for biomedical applications, including matrices for controlled drug release. We present a method for defining drug dosing in screening assays by light-activated cross-linking of PEG-diacrylate hydrogels with embedded drug-loaded liposome...

  3. Novel thermosensitive hydrogel for preventing formation of abdominal adhesions

    Directory of Open Access Journals (Sweden)

    Gao X

    2013-07-01

    Full Text Available Xiang Gao,1,2 Xiaohui Deng,3 Xiawei Wei,2 Huashan Shi,2 Fengtian Wang,2 Tinghong Ye,2 Bin Shao,2 Wen Nie,2 Yuli Li,2 Min Luo,2 Changyang Gong,2 Ning Huang1 1Department of Pathophysiology, College of Preclinical and Forensic Medical Sciences, Sichuan University, Chengdu, 2State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, 3Department of Human Anatomy, Xinxiang Medical University, Xinxiang, People’s Republic of China Abstract: Adhesions can form after almost any type of abdominal surgery. Postoperative adhesions can be prevented by improved surgical techniques, such as reducing surgical trauma, preventing ischemia, and avoiding exposure of the peritoneal cavity to foreign materials. Although improved surgical techniques can potentially reduce formation of adhesions, they cannot be eliminated completely. Therefore, finding more effective methods to prevent postoperative adhesions is imperative. Recently, we found that a novel thermosensitive hydrogel, ie, poly(ε-caprolactone-poly(ethylene glycol-poly(ε-caprolactone (PCEC had the potential to prevent postoperative adhesions. Using the ring-opening polymerization method, we prepared a PCEC copolymer which could be dissolved and assembled at 55°C into PCEC micelles with mean size of 25 nm. At body temperature, a solution containing PCEC micelles could convert into a hydrogel. The PCEC copolymer was biodegradable and had low toxicity in vitro and in vivo. We found that most animals in a hydrogel-treated group (n = 10 did not develop adhesions. In contrast, 10 untreated animals developed adhesions that could only be separated by sharp dissection (P < 0.001. The hydrogel could adhere to peritoneal wounds and degraded gradually over 7–9 days, transforming into a viscous fluid that was completely absorbed within 12 days. The injured parietal and visceral peritoneum remesothelialized over about seven and nine days

  4. Co-electrospun blends of PU and PEG as potential biocompatible scaffolds for small-diameter vascular tissue engineering

    International Nuclear Information System (INIS)

    Wang, Heyun; Feng, Yakai; Fang, Zichen; Yuan, Wenjie; Khan, Musammir

    2012-01-01

    A small-diameter vascular graft (inner diameter 4 mm) was fabricated from polyurethane (PU) and poly(ethylene glycol) (PEG) solutions by blend electrospinning technology. The fiber diameter decreased from 1023 ± 185 nm to 394 ± 106 nm with the increasing content of PEG in electrospinning solutions. The hybrid PU/PEG scaffolds showed randomly nanofibrous morphology, high porosity and well-interconnected porous structure. The hydrophilicity of these scaffolds had been improved significantly with the increasing contents of PEG. The mechanical properties of electrospun hybrid PU/PEG scaffolds were obviously different from that of PU scaffold, which was caused by plasticizing or hardening effect imparted by PEG composition. Under hydrated state, the hybrid PU/PEG scaffolds demonstrated low mechanical performance due to the hydrophilic property of materials. Compared with dry PU/PEG scaffolds with the same content of PEG, the tensile strength and elastic modulus of hydrated PU/PEG scaffolds decreased significantly, while the elongation at break increased. The hybrid PU/PEG scaffolds demonstrated a lower possibility of thrombi formation than blank PU scaffold in platelet adhesion test. The hemolysis assay illustrated that all scaffolds could act as blood contacting materials. To investigate further in vitro cytocompatibility, HUVECs were seeded on the scaffolds and cultured over 14 days. The cells could attach and proliferate well on the hybrid scaffolds than blank PU scaffold, and form a cell monolayer fully covering on the PU/PEG (80/20) hybrid scaffold surface. The results demonstrated that the electrospun hybrid PU/PEG tubular scaffolds possessed the special capacity with excellent hemocompatibility while simultaneously supporting extensive endothelialization with the 20 and 30% content of PEG in hybrid scaffolds. - Highlights: ► We develop small-diameter vascular grafts made of PU and PEG by electrospinning. ► The hybrid scaffolds could suppress the platelet

  5. Clicked bis-PEG-peptide conjugates for studying calmodulin-Kv7.2 channel binding.

    Science.gov (United States)

    Bonache, M Angeles; Alaimo, Alessandro; Malo, Covadonga; Millet, Oscar; Villarroel, Alvaro; González-Muñiz, Rosario

    2014-11-28

    The recombinant Kv7.2 calmodulin (CaM) binding site (Q2AB CaMBD) shows a high tendency to aggregate, thus complicating biochemical and structural studies. To facilitate these studies we have conceived bis-PEG-peptide CaMBD-mimetics linking helices A and B in single, easy to handle molecules. Short PEG chains were selected as spacers between the two peptide molecules, and a Cu(i)-catalyzed cycloaddition (CuAAC) protocol was used to assemble the final bis-PEG-peptide conjugate, by the convenient functionalization of PEG arms with azide and alkyne groups. The resulting conjugates, with a certain helical character in TFE solutions (CD), showed nanomolar affinity in a fluorescence CaM binding in vitro assay, higher than just the sum of the precursor PEG-peptide affinities, thus validating our design. The approach to these first described examples of Kv7.2 CaMBD-mimetics could pave the way to chimeric conjugates merging helices A and B from different Kv7 subunits.

  6. Stabilization of Resveratrol in Blood Circulation by Conjugation to mPEG and mPEG-PLA Polymers: Investigation of Conjugate Linker and Polymer Composition on Stability, Metabolism, Antioxidant Activity and Pharmacokinetic Profile

    Science.gov (United States)

    Siddalingappa, Basavaraj; Benson, Heather A. E.; Brown, David H.; Batty, Kevin T.; Chen, Yan

    2015-01-01

    Resveratrol is naturally occurring phytochemical with diverse biological activities such as chemoprevention, anti-inflammatory, anti-cancer, anti-oxidant. But undergoes rapid metabolism in the body (half life 0.13h). Hence Polymer conjugation utilizing different chemical linkers and polymer compositions was investigated for enhanced pharmacokinetic profile of resveratrol. Ester conjugates such as α-methoxy-ω-carboxylic acid poly(ethylene glycol) succinylamide resveratrol (MeO-PEGN-Succ-RSV) (2 and 20 kDa); MeO-PEG succinyl ester resveratrol (MeO-PEGO-Succ-RSV) (2 kDa); α-methoxy poly(ethylene glycol)-co-polylactide succinyl ester resveratrol (MeO-PEG-PLAO-Succ-RSV) (2 and 6.6kDa) were prepared by carbodiimide coupling reactions. Resveratrol-PEG ethers (2 and 5 kDa) were synthesized by alkali-mediated etherification. All polymer conjugates were fully characterized in vitro and the pharmacokinetic profile of selected conjugates was characterized in rats. Buffer and plasma stability of conjugates was dependent on polymer hydrophobicity, aggregation behavior and PEG corona, with MeO-PEG-PLAO-Succ-RSV (2 kDa) showing a 3h half-life in rat plasma in vitro. Polymer conjugates irrespective of linker chemistry protected resveratrol against metabolism in vitro. MeO-PEG-PLAO-Succ-RSV (2 kDa), Resveratrol-PEG ether (2 and 5 kDa) displayed improved pharmacokinetic profiles with significantly higher plasma area under curve (AUC), slower clearance and smaller volume of distribution, compared to resveratrol. PMID:25799413

  7. Surfactant-assisted carbon doping in ZnO nanowires using Poly Ethylene Glycol (PEG)

    Energy Technology Data Exchange (ETDEWEB)

    Amanullah, Malik; Javed, Qurat-ul-Ain, E-mail: Quratulain@sns.nust.edu.pk; Rizwan, Syed

    2016-09-01

    Zinc Oxide (ZnO) provides unique properties owing to its wide bandgap, large resistivity range and possibility to tune the physical properties. The surfactant assisted carbon doping was made possible due to the lowering of surface energy. The ZnO and carbon doped ZnO (C-ZnO) nanowires fabricated by hydrothermal process, Poly Ethylene Glycol (PEG) is used as surfactant in hydrothermal synthesis followed by post growth annealing treatment at 600 °C–700 °C. At 5%–10% of diluted PEG carbon is doped in ZnO. The crystallinity, structural morphology and elemental composition analysis for ZnO and C-ZnO nanowires were carried out using X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques respectively. Carbon doping in ZnO nanowires in the presence of different percentage of surfactant is explained by calculating the change in surface energy with respect to change in PEG molecule concentration. It was found that the surface energy per molecule modulates from 3.92 × 10{sup −8} J/m{sup 2} to 8.16 × 10{sup −7} J/m{sup 2} in the PEG concentration range between 5% and 10%. Our results provides a new theoretical calculations, implemented on real system, to observe the details of PEG-assisted Carbon doping in II-VI semiconductor nanowires. - Highlights: • ZnO and C-ZnO was synthesized by PEG assisted post growth annealing process. • At 5% and 10% of PEG successful synthesis of C-ZnO was found. • XRD, SEM and EDX characterizations confirm the successful synthesis of ZnO and C-ZnO. • Change in surface energy with respect to PEG molecule concentration was calculated.

  8. Preparation of flexible PLA/PEG-POSS nanocomposites by melt blending and radiation crosslinking

    International Nuclear Information System (INIS)

    Jung, Chang-Hee; Hwang, In-Tae; Jung, Chan-Hee; Choi, Jae-Hak

    2014-01-01

    In this study, poly(lactic acid) (PLA)/poly(ethylene glycol)-functionalized polyhedral oligomeric silsesquioxane (PEG-POSS) nanocomposites with or without triallyl isocyanurate (TAIC) were investigated by melt blending and electron beam irradiation to enhance the flexibility of PLA. Based on the results of the crosslinking degree measurements, the PLA/PEG-POSS nanocomposites were crosslinked by electron beam irradiation in the presence of triallyl isocyanurate (TAIC) and their crosslinking degree reached up to 80% based on the absorbed dose and their compositions. From the results of the FE-SEM and EDX Si-mapping, the crosslinked PLA/PEG-POSS nanocomposites were homogenous without a micro-phase separation or radiation-induced morphological change. Based on the results of the tensile test, the PLA/PEG-POSS nanocomposites containing 15 wt% PEG-POSS exhibited the highest flexibility, and their tensile strength showed a maximum value of 44.5 MPa after electron beam irradiation at an absorbed dose of 100 kGy in the presence of TAIC, which is comparable to non-biodegradable polypropylene. The results of the dynamic mechanical analysis revealed that the crosslinked PLA/PEG-POSS nanocomposites exhibited a higher thermal resistance above their melting temperature in comparison to that of the neat PLA, although their glass transition temperature was lower than that of the neat PLA. The enzymatic biodegradation test revealed that the PLA/PEG-POSS nanocomposites were biodegradable even though their biodegradability was deteriorated in comparison to that of the neat PLA. - Highlights: • PLA/PEG-POSS nanocomposites were prepared by melt blending. • The nanocomposites containing TAIC were crosslinked by electron beam irradiation. • The mechanical properties of the nanocomposites were comparable to polypropylene. • The crosslinked nanocomposites can be biodegradable

  9. Gel structure has an impact on pericellular and extracellular matrix deposition, which subsequently alters metabolic activities in chondrocyte-laden PEG hydrogels.

    Science.gov (United States)

    Nicodemus, G D; Skaalure, S C; Bryant, S J

    2011-02-01

    While designing poly(ethylene glycol) hydrogels with high moduli suitable for in situ placement is attractive for cartilage regeneration, the impact of a tighter crosslinked structure on the organization and deposition of the matrix is not fully understood. The objectives of this study were to characterize the composition and spatial organization of new matrix as a function of gel crosslinking and study its impact on chondrocytes in terms of anabolic and catabolic gene expression and catabolic activity. Bovine articular chondrocytes were encapsulated in hydrogels with three crosslinking densities (compressive moduli 60, 320 and 590 kPa) and cultured for 25 days. Glycosaminoglycan production increased with culture time and was greatest in the gels with lowest crosslinking. Collagens II and VI, aggrecan, link protein and decorin were localized to pericellular regions in all gels, but their presence decreased with increasing gel crosslinking. Collagen II and aggrecan expression were initially up-regulated in gels with higher crosslinking, but increased similarly up to day 15. Matrix metalloproteinase (MMP)-1 and MMP-13 expression were elevated (∼25-fold) in gels with higher crosslinking throughout the study, while MMP-3 was unaffected by gel crosslinking. The presence of aggrecan and collagen degradation products confirmed MMP activity. These findings indicate that chondrocytes synthesized the major cartilage components within PEG hydrogels, however, gel structure had a significant impact on the composition and spatial organization of the new tissue and on how chondrocytes responded to their environment, particularly with respect to their catabolic expression. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. PEG and Thickeners: A Critical Interaction Between Polyethylene Glycol Laxative and Starch-Based Thickeners.

    Science.gov (United States)

    Carlisle, Brian J; Craft, Garrett; Harmon, Julie P; Ilkevitch, Alina; Nicoghosian, Jenik; Sheyner, Inna; Stewart, Jonathan T

    2016-09-01

    Clinicians commonly encounter dysphagia and constipation in a skilled nursing population. Increasing the viscosity of liquids, usually with a starch- or xanthan gum-based thickener, serves as a key intervention for patients with dysphagia. We report a newly identified and potentially dangerous interaction between polyethylene glycol 3350 laxative (PEG) and starch-thickened liquids. A patient requiring nectar-thickened liquids became constipated, and medical staff prescribed PEG for constipation. His nurse observed that the thickened apple juice immediately thinned to near-water consistency when PEG was added. She obtained the same results with thickened water and coffee. We quantified this phenomenon by isothermal rotational rheology. Results confirmed a precipitous loss of thickening when PEG was added to starch-based thickeners but not with xanthan gum-based thickeners. Clinicians and front-line staff should be aware of this potentially critical interaction between PEG- and starch-based thickeners. Although confirmatory studies are needed, our preliminary data suggest that PEG may be compatible with xanthan gum-- based thickeners. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. All rights reserved.

  11. mPEG-PLA Micelle for Delivery of Effective Parts of Andrographis Paniculata.

    Science.gov (United States)

    Yao, Hailu; Song, Shiyong; Miao, Xiaolu; Liu, Xiao; Zhao, Junli; Wang, Zhen; Shao, Xiaoting; Zhang, Yu; Han, Guang

    2018-01-01

    Many studies have shown that Andrographis paniculata (Burm. f.) Nees has a good anti-tumor effect, but poor solubility in water and poor bioavailability hinder the modernization of it. To formulate the effective parts (mainly diterpene lactones) of Andrographis paniculata (AEP) into targeting drug delivery system, a series of poly(ethylene glycol)-poly(D.L-lactic acid)(mPEG-PLA) with different ratio of hydrophilic and hydrophobic segment was synthetized to encapsulate AEP. AEP micelles were prepared by a simple solvent-evaporation method. According to the loading capacity, the best polymer was chosen. mPEG-PLA micelles were characterized in terms of drug entrapping efficiency, loading capacity, size, the crystalline state of AEP, stability and release profile. Meanwhile, the cytotoxicity of micelles on mouse breast cancer 4T-1 was investigated. These micelle (mPEG-PLA-AEP) particles had a size of (92.84±5.63) nm and a high entrapping efficiency and loading capacity of (91.00±11.53)% and (32.14±3.02)%(w/w), respectively. The powder DSC showed that drugs were well encapsulated in the core of micelles. mPEG-PLA-AEP had a good stability against salt dissociation, protein adsorption and anion substitution and the solubility of andrographolide (AG) and 14-deoxy-11,12-didehydroandrographolide(DDAG) in AEP increased 4.51 times and 2.12 times in water, and the solubility of DAG showed no difference. mPEG-PLA-AEP had the same release profile in different dissolution medium. Cytotoxicity testing in vitro demonstrated that mPEG-PLA-AEP exhibited higher cell viability inhibition in mouse breast cancer 4T-1 than free AEP. mPEG-PLA micelles offer a promising alternative for TCM therapy with higher solubility and improved antitumor effect. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Gadolinium-conjugated PLA-PEG nanoparticles as liver targeted molecular MRI contrast agent.

    Science.gov (United States)

    Chen, Zhijin; Yu, Dexin; Liu, Chunxi; Yang, Xiaoyan; Zhang, Na; Ma, Chunhong; Song, Jibin; Lu, Zaijun

    2011-09-01

    A nanoparticle magnetic resonance imaging (MRI) contrast agent targeted to liver was developed by conjugation of gadolinium (Gd) chelate groups onto the biocompatible poly(l-lactide)-block-poly (ethylene glycol) (PLA-PEG) nanoparticles. PLA-PEG conjugated with diethylenetriaminopentaacetic acid (DTPA) was used to formulate PLA-PEG-DTPA nanoparticles by solvent diffusion method, and then Gd was loaded onto the nanoparticles by chelated with the unfolding DTPA on the surface of the PLA-PEG-DTPA nanoparticles. The mean size of the nanoparticles was 265.9 ± 6.7 nm. The relaxivity of the Gd-labeled nanoparticles was measured, and the distribution in vivo was evaluated in rats. Compared with conventional contrast agent (Magnevist), the Gd-labeled PLA-PEG nanoparticles showed significant enhancement both on liver targeting ability and imaging signal intensity. The T(1) and T(2) relaxivities per [Gd] of the Gd-labeled nanoparticles was 18.865 mM(-1) s(-1) and 24.863 mM(-1) s(-1) at 3 T, respectively. In addition, the signal intensity in vivo was stronger comparing with the Gd-DTPA and the T(1) weight time was lasting for 4.5 h. The liver targeting efficiency of the Gd-labeled PLA-PEG nanoparticles in rats was 14.57 comparing with Magnevist injection. Therefore, the Gd-labeled nanoparticles showed the potential as targeting molecular MRI contrast agent for further clinical utilization.

  13. Crutch art painting in the Middle Ages as orthopaedic heritage (part II: the peg leg, the bent-knee peg and the beggar).

    Science.gov (United States)

    Hernigou, Philippe

    2014-07-01

    Little of historical value about crutches can be ascertained before the Middle Ages. In contrast, the Middle Ages offer many examples for the study of crutches. Even if no medical report can be found, the immense patronage of the Church, encouraging artists to portray the saints and their miracles, has left great masterpieces that drew people with crutches. Pictures and the history of medieval conceptions of disability appear to provide an interesting chronicle of surgery of the peg leg and the bent-knee peg among the representations of cripples and beggars.

  14. Preparation and Characterization of Cationic PLA-PEG Nanoparticles for Delivery of Plasmid DNA

    Directory of Open Access Journals (Sweden)

    Zou Weiwei

    2009-01-01

    Full Text Available Abstract The purpose of the present work was to formulate and evaluate cationic poly(lactic acid-poly(ethylene glycol (PLA-PEG nanoparticles as novel non-viral gene delivery nano-device. Cationic PLA-PEG nanoparticles were prepared by nanoprecipitation method. The gene loaded nanoparticles were obtained by incubating the report gene pEGFP with cationic PLA-PEG nanoparticles. The physicochemical properties (e.g., morphology, particle size, surface charge, DNA binding efficiency and biological properties (e.g., integrity of the released DNA, protection from nuclease degradation, plasma stability, in vitro cytotoxicity, and in vitro transfection ability in Hela cells of the gene loaded PLA-PEG nanoparticles were evaluated, respectively. The obtained cationic PLA-PEG nanoparticles and gene loaded nanoparticles were both spherical in shape with average particle size of 89.7 and 128.9 nm, polydispersity index of 0.185 and 0.161, zeta potentials of +28.9 and +16.8 mV, respectively. The obtained cationic PLA-PEG nanoparticles with high binding efficiency (>95% could protect the loaded DNA from the degradation by nuclease and plasma. The nanoparticles displayed sustained-release properties in vitro and the released DNA maintained its structural and functional integrity. It also showed lower cytotoxicity than Lipofectamine 2000 and could successfully transfect gene into Hela cells even in presence of serum. It could be concluded that the established gene loaded cationic PLA-PEG nanoparticles with excellent properties were promising non-viral nano-device, which had potential to make cancer gene therapy achievable.

  15. A Retrospective Study of Association between Peg-shaped Maxillary Lateral Incisors and Dental Anomalies.

    Science.gov (United States)

    Kim, Jae-Hwan; Choi, Nam-Ki; Kim, Seon-Mi

    The purpose of this study was to investigate the prevalence of peg-shaped maxillary lateral incisors and the incidence of associated dental anomalies in children. We investigated the prevalence of peg-laterals and incidence of associated dental anomalies in 3,834 children aged 7-15 who visited the Department of Pediatric Dentistry from January 2010 to December 2015 and underwent panoramic radiographs. The prevalence of peg-laterals was 1.69% in boys, 1.75% in girls, and 1.72% overall. Among children with peg-laterals, the frequencies of associated dental anomalies were as follows: congenitally missing teeth, 31.8%; dens invaginatus, 19.7%; palatally displaced canines, 12.1%; supernumerary teeth, 7.6%; and transposition, 7.6%. As children with peg-laterals have a higher incidence of other dental anomalies, careful consideration is needed when planning diagnosis and treatment.

  16. PNA-PEG modified silicon platforms as functional bio-interfaces for applications in DNA microarrays and biosensors.

    Science.gov (United States)

    Cattani-Scholz, Anna; Pedone, Daniel; Blobner, Florian; Abstreiter, Gerhard; Schwartz, Jeffrey; Tornow, Marc; Andruzzi, Luisa

    2009-03-09

    The synthesis and characterization of two types of silicon-based biofunctional interfaces are reported; each interface bonds a dense layer of poly(ethylene glycol) (PEG(n)) and peptide nucleic acid (PNA) probes. Phosphonate self-assembled monolayers were derivatized with PNA using a maleimido-terminated PEG(45). Similarly, siloxane monolayers were functionalized with PNA using a maleimido-terminated PEG(45) spacer and were subsequently modified with a shorter methoxy-terminated PEG(12) ("back-filling"). The long PEG(45) spacer was used to distance the PNA probe from the surface and to minimize undesirable nonspecific adsorption of DNA analyte. The short PEG(12) "back-filler" was used to provide additional passivation of the surface against nonspecific DNA adsorption. X-ray photoelectron spectroscopic (XPS) analysis near the C 1s and N 1s ionization edges was done to characterize chemical groups formed in the near-surface region, which confirmed binding of PEG and PNA to the phosphonate and silane films. XPS also indicated that additional PEG chains were tethered to the surface during the back-filling process. Fluorescence hybridization experiments were carried out with complementary and noncDNA strands; both phosphonate and siloxane biofunctional surfaces were effective for hybridization of cDNA strands and significantly reduced nonspecific adsorption of the analyte. Spatial patterns were prepared by polydimethylsiloxane (PDMS) micromolding on the PNA-functionalized surfaces; selective hybridization of fluorescently labeled DNA was shown at the PNA functionalized regions, and physisorption at the probe-less PEG-functionalized regions was dramatically reduced. These results show that PNA-PEG derivatized phosphonate monolayers hold promise for the smooth integration of device surface chemistry with semiconductor technology for the fabrication of DNA biosensors. In addition, our results confirm that PNA-PEG derivatized self-assembled carboxyalkylsiloxane films are

  17. Application of 10BSH entrapped transferrin-PEG-liposome to boron neutron-capture therapy (BNCT) for solid tumor

    International Nuclear Information System (INIS)

    Maruyama, K.; Ishida, O.; Iwatsuru, M.; Yanagie, H.; Eriguchi, M.; Kobayashi, H.

    2000-01-01

    The successful treatment of cancer by BNCT requires the selective concentration of 10 B within malignant tumor cells. Intracellular targeting ability and cytotoxic effects of 10 B entrapped TF-PEG-liposomes, in which TF is covalently linked to the distal terminal of PEG chains on the external surface of PEG-liposomes, were examined in Colon 26 tumor-bearing mice. TF-PEG-liposomes readily bound to tumor cells in vivo, and were internalized by receptor-mediated endocytosis. 10 B-PEG-liposomes and 10 B-TF-PEG-liposomes showed prolonged residence time in the circulation and low RES uptake in tumor-bearing mice, resulting in enhanced extravasation of the liposomes into the solid tumor tissue and reached high level of 10 B content in tumor. After thermal neutron irradiation of mice injected with 10 B-PEG-liposomes or 10 B-TF-PEG-liposome, tumor growth was suppressed relative to controls. These results suggest that intravenous injection of 10 B TF-PEG-liposome can increase the intracellular retention of 10 B atoms, which were introduced by receptor mediated endocytosis after binding, causing tumor growth suppression in vivo upon thermal neutron irradiation. (author)

  18. Quantitative fabrication, performance optimization and comparison of PEG and zwitterionic polymer antifouling coatings.

    Science.gov (United States)

    Xing, Cheng-Mei; Meng, Fan-Ning; Quan, Miao; Ding, Kai; Dang, Yuan; Gong, Yong-Kuan

    2017-09-01

    A versatile fabrication and performance optimization strategy of PEG and zwitterionic polymer coatings is developed on the sensor chip of surface plasma resonance (SPR) instrument. A random copolymer bearing phosphorylcholine zwitterion and active ester side chains (PMEN) and carboxylic PEG coatings with comparable thicknesses were deposited on SPR sensor chips via amidation coupling on the precoated polydopamine (PDA) intermediate layer. The PMEN coating showed much stronger resistance to bovine serum albumin (BSA) adsorption than PEG coating at very thin thickness (∼1nm). However, the BSA resistant efficacy of PEG coating could exceed that of PMEN due to stronger steric repelling effect when the thickness increased to 1.5∼3.3nm. Interestingly, both the PEG and PMEN thick coatings (≈3.6nm) showed ultralow fouling by BSA and bovine plasma fibrinogen (Fg). Moreover, changes in the PEG end group from -OH to -COOH, protein adsorption amount could increase by 10-fold. Importantly, the optimized PMEN and PEG-OH coatings were easily duplicated on other substrates due to universal adhesion of the PDA layer, showed excellent resistance to platelet, bacteria and proteins, and no significant difference in the antifouling performances was observed. These detailed results can explain the reported discrepancy in performances between PEG and zwitterionic polymer coatings by thickness. This facile and substrate-independent coating strategy may benefit the design and manufacture of advanced antifouling biomedical devices and long circulating nanocarriers. Prevention of biofouling is one of the biggest challenges for all biomedical applications. However, it is very difficult to fabricate a highly hydrophilic antifouling coating on inert materials or large devices. In this study, PEG and zwitterion polymers, the most widely investigated polymers with best antifouling performance, are conveniently immobilized on different kinds of substrates from their aqueous solutions by

  19. PEG capped methotrexate silver nanoparticles for efficient anticancer activity and biocompatibility.

    Science.gov (United States)

    Muhammad, Zarmina; Raza, Abida; Ghafoor, Sana; Naeem, Ayesha; Naz, Syeda Sohaila; Riaz, Sundus; Ahmed, Wajiha; Rana, Nosheen Fatima

    2016-08-25

    Nanocarriers endow tremendous benefits to the drug delivery systems depending upon the specific properties of either component. These benefits include, increase in the drug blood retention time, reduced efflux, additional toxicity and targeted delivery. Methotrexate (MTX) is clinically used for cancer treatment. Higher dosage of MTX results in hepatic and renal toxicity. In this study methotrexate silver nanoparticles (Ag-MTX) coated with polyethylene glycol (PEG) are synthesized and characterized. Their anticancer activity and biocompatibility is also evaluated. Ag-MTX nanoparticles are synthesized by chemical reduction method. They are characterized by Ultraviolet-Visible Spectroscopy and Fourier Transform Infrared Spectroscopy. Average size of PEG coated Ag-MTX nanoparticles (PEG-Ag-MTX nanoparticles) is 12nm. These particles exhibited improved anticancer activity against MCF-7 cell line. Hemolytic activity of these particles was significantly less than MTX. PEG-Ag-MTX nanoparticles are potential nanocarrier of methotrexate which may offer MTX based cancer treatment with reduced side effects. In-vivo investigations should be carried out to explore them in detail. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Synthesis and preliminary biodistribution studies of [131I]SIB-PEG4-CHC in tumor-bearing mice

    International Nuclear Information System (INIS)

    Xiaobei Zheng; Jing Yang; Xiaojiang Duan; Tingting Niu; Wangsuo Wu; Jianjun Wang; Feng Dong

    2011-01-01

    This work reports the synthesis and preliminary biodistribution results of [ 131 I]SIB-PEG 4 -CHC in tumor-bearing mice. The tributylstannyl precursor ATE-PEG 4 -CHC was synthesized by conjugation of ATE to amino pegylated colchicine NH 2 -PEG 4 -CHC. [ 131 I]SIB-PEG 4 -CHC was radiosynthesized by electrophilic destannylation of the precursor with a yield of ∼44%. The radiochemical purity (RCP) appeared to be >95% by a Sep-Pak cartridge purification. [ 131 I]SIB-PEG 4 -CHC was lipophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that [ 131 I]SIB-PEG 4 -CHC cleared from background rapidly, and didn't deiodinate in vivo. However, the poor tumor localization excluded it from further investigations as a tumor-targeted radiopharmaceuticals. (author)

  1. Synthesis and in vitro cytotoxicity of mPEG-SH modified gold nanorods

    Science.gov (United States)

    Didychuk, Candice L.; Ephrat, Pinhas; Belton, Michelle; Carson, Jeffrey J. L.

    2008-02-01

    Plasmon-resonant gold nanorods show great potential as an agent for contrast-enhanced biomedical imaging or for phototherapeutics. This is primarily due to the high molar extinction coefficient at the absorption maximum and the dependence of the wavelength of the absorption maximum on the aspect ratio, which is tunable in the near-infrared (NIR) during synthesis. Although gold nanorods can be produced in high-yield through the seed-mediated growth technique, the presence of residual cetyltrimethylammonium bromide (CTAB), a stabilizing surfactant required for nanorod growth, interferes with cell function and causes cytotoxicity. To overcome this potential obstacle to in vivo use, we synthesized gold nanorods and conjugated them to a methoxy (polyethylene glycol)-thiol (mPEG (5000)-SH). This approach yielded mPEG-SH modified gold nanorods with optical and morphometric properties that were similar to raw (CTAB) nanorods. Both the CTAB and mPEG-SH nanorods were tested for cytotoxicity against the HL-60 human leukemia cell line by trypan blue exclusion, and the mPEG-SH modified gold nanorods were also tested against a rat insulinoma (RIN-38) and squamous cell carcinoma (SCCVII) cell line. Cells incubated for 24 h with the mPEG-SH modified nanorods had little change in cell viability compared to cells incubated with vehicle alone. This was in contrast to cytotoxicity of CTAB nanorods on HL-60 cells. These results suggest that mPEG-SH modified gold nanorods are better suited for cell loading protocols and injection into animals and facilitate their use for imaging and phototherapeutic purposes.

  2. Sustainable and Low Viscous 1-Allyl-3-methylimidazolium Acetate + PEG Solvent for Cellulose Processing

    Directory of Open Access Journals (Sweden)

    Airong Xu

    2017-02-01

    Full Text Available Developing sustainable, low viscous and efficient solvents are always advantageous to the processing/fabricating of cellulose materials in practical applications. To this end, in this work novel solvents were developed; ([Amim][CH3COO]/PEG by dissolving polyethylene glycol 200 (PEG-200 in 1-allyl-3-methylimidazolium acetate ([Amim][CH3COO]. The solubilities of cellulose in [Amim][CH3COO]/PEG solvents were determined as a function of temperature, and the possible dissolution mechanism of cellulose in [Amim][CH3COO]/PEG solvent was investigated. The novel solvent exhibits outstanding advantages for good dissolution capacity of cellulose, such as low viscosity, negligible vapor pressure, and recycling capability. The [CH3COO]− anion and the [Amim]+ cation of [Amim][CH3COO] in [Amim][CH3COO]/PEG-10 are the driving force for cellulose dissolution verified by the 13C NMR spectra. In addition, the regenerated cellulose films from [Amim][CH3COO]/PEG solvent were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR, and thermogravimetric analysis (TGA to estimate their morphologies and structures.

  3. Influence of PEG coating on the oral bioavailability of gold nanoparticles in rats.

    Science.gov (United States)

    Alalaiwe, Ahmed; Roberts, Georgia; Carpinone, Paul; Munson, John; Roberts, Stephen

    2017-11-01

    Metallic nanoparticles can be produced in a variety of shapes, sizes, and surface chemistries, making them promising potential tools for drug delivery. Most studies to date have evaluated uptake of metallic nanoparticles from the GI tract with methods that are at best semi-quantitative. This study used the classical method of comparing blood concentration area under the curve (AUC) following intravenous and oral doses to determine the oral bioavailability of 1, 2 and 5 kDa PEG-coated 5 nm gold nanoparticles (AuNPs). Male rats were given a single intravenous dose (0.8 mg/kg) or oral (gavage) dose (8 mg/kg) of a PEG-coated AuNP, and the concentration of gold was measured in blood over time and in tissues (liver, spleen and kidney) at sacrifice. Blood concentrations following oral administration were inversely related to PEG size, and the AUC in blood was significantly greater for the 1 kDa PEG-coated AuNPs than particles coated with 2 or 5 kDa PEG. However, bioavailabilities of all of the particles were very low (bioavailability of AuNPs coated with PEG in the 1-5 kDa range, this study demonstrates the utility of applying the blood AUC approach to assess the quantitative oral bioavailability of metallic nanoparticles.

  4. Improving dielectric permittivity by incorporating PDMS-PEG block copolymer into PDMS network

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    introduces different properties in terms of contact angles, dielectric permittivity and rheological behaviour. All morphologies of PDMS-PEG block copolymer in this study exhibit high storage permittivity; at the same time the loss permittivity is even higher which implies that the synthesized PDMS-PEG block...

  5. ``Sheddable'' PEG-lipid to balance the contradiction of PEGylation between long circulation and poor uptake

    Science.gov (United States)

    Zhao, Caiyan; Deng, Hongzhang; Xu, Jing; Li, Shuyi; Zhong, Lin; Shao, Leihou; Wu, Yan; Liang, Xing-Jie

    2016-05-01

    PEGylated lipids confer longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. In order to balance the contradiction between the advantages of long circulation and the disadvantages of poor uptake of PEGylated lipids, we prepared a ``sheddable'' PEG-lipid micelle system based on the conjugation of PEG and phosphatidyl ethanolamine (DSPE) with a pH sensitive benzoic imine bond. In a physiological environment, the PEG-protected micelles were not readily taken up by the reticuloendothelial system (RES) and could be successfully delivered to tumor tissue by the EPR effect. In a tumor acidic microenvironment, the PEG chains detached from the surfaces of the micelles while the degree of linker cleavage could not cause a significant particle size change, which facilitated the carrier binding to tumor cells and improved the cellular uptake. Subsequently, the ``sheddable'' PEG-lipid micelles easily internalized into cells and the increased acidity in the lysosomes further promoted drug release. Thus, this ``sheddable'' PEG-lipid nanocarrier could be a good candidate for effective intracellular drug delivery in cancer chemotherapy.PEGylated lipids confer longer systemic circulation and tumor accumulation via the enhanced permeability and retention (EPR) effect. However, PEGylation inhibits cellular uptake and subsequent endosomal escape. In order to balance the contradiction between the advantages of long circulation and the disadvantages of poor uptake of PEGylated lipids, we prepared a ``sheddable'' PEG-lipid micelle system based on the conjugation of PEG and phosphatidyl ethanolamine (DSPE) with a pH sensitive benzoic imine bond. In a physiological environment, the PEG-protected micelles were not readily taken up by the reticuloendothelial system (RES) and could be successfully delivered to tumor tissue by the EPR effect. In a tumor acidic

  6. pH and temperature dual-sensitive liposome gel based on novel cleavable mPEG-Hz-CHEMS polymeric vaginal delivery system

    Directory of Open Access Journals (Sweden)

    Chen D

    2012-05-01

    Full Text Available Daquan Chen,1,2 Kaoxiang Sun,1,2 Hongjie Mu,1 Mingtan Tang,3 Rongcai Liang,1,2 Aiping Wang,1,2 Shasha Zhou,1 Haijun Sun,1 Feng Zhao,1 Jianwen Yao,1 Wanhui Liu1,21School of Pharmacy, Yantai University, 2State Key Laboratory of Longacting and Targeting Drug Delivery Systems, Yantai, 3School of Pharmaceutical Sciences, Shandong University, Jinan, People's Republic of ChinaBackground: In this study, a pH and temperature dual-sensitive liposome gel based on a novel cleavable hydrazone-based pH-sensitive methoxy polyethylene glycol 2000-hydrazone-cholesteryl hemisuccinate (mPEG-Hz-CHEMS polymer was used for vaginal administration.Methods: The pH-sensitive, cleavable mPEG-Hz-CHEMS was designed as a modified pH-sensitive liposome that would selectively degrade under locally acidic vaginal conditions. The novel pH-sensitive liposome was engineered to form a thermogel at body temperature and to degrade in an acidic environment.Results: A dual-sensitive liposome gel with a high encapsulation efficiency of arctigenin was formed and improved the solubility of arctigenin characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. The dual-sensitive liposome gel with a sol-gel transition at body temperature was degraded in a pH-dependent manner, and was stable for a long period of time at neutral and basic pH, but cleavable under acidic conditions (pH 5.0. Arctigenin encapsulated in a dual-sensitive liposome gel was more stable and less toxic than arctigenin loaded into pH-sensitive liposomes. In vitro drug release results indicated that dual-sensitive liposome gels showed constant release of arctigenin over 3 days, but showed sustained release of arctigenin in buffers at pH 7.4 and pH 9.0.Conclusion: This research has shed some light on a pH and temperature dual-sensitive liposome gel using a cleavable mPEG-Hz-CHEMS polymer for vaginal delivery.Keywords: mPEG-Hz-CHEMS polymer, pH-sensitive liposomes, thermosensitive

  7. Incorporation of fluconazole in copolymer PMMA-g-PEG derivatives

    International Nuclear Information System (INIS)

    Silveira, B.M.; Santos, V.M.R. dos; Novack, K.M.; Lopes, S.A.

    2014-01-01

    The graft copolymer PMMA-g-PEG went through chemical transformations in its chain through acetylation, halogenation, methylation and esterification followed by hydrolysis reactions. Subsequently, the copolymer PMMA-g-PEG derivatives passed through the process of emulsification and incorporation of the drug fluconazole. Derivatives copolymers were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) after incorporation in order to evaluate their effectiveness. The efficiency of incorporation was observed and it was also verified that the complexity of polymer chain influence in the incorporated fluconazole content. (author)

  8. The exploration of endocytic mechanisms of PLA-PEG nanoparticles prepared by coaxialtri-capillary electrospray-template removal method.

    Science.gov (United States)

    Chen, Jiaming; Cao, Lihua; Cui, Yuecheng; Tu, Kehua; Wang, Hongjun; Wang, Li-Qun

    2018-01-01

    The nano-sized poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) particles with core-shell structure were efficiently prepared by using coaxial tri-capillary electrospray-template removal method. The cellular uptake mechanism, intracellular distribution and exocytosis in A549 cell model of electrosprayed PLA-PEG nanoparticles were systemically studied. The drug release behavior of electrosprayed PLA-PEG nanoparticles were also investigated. Our results showed that PLA-PEG nanoparticles can be endocytosed quickly by A549 cells. The cellular uptake of PLA-PEG nanoparticles was an energy dependent endocytosis process. Caveolae-mediated endocytosis was only one of endocytosis pathways in A549 cells for PLA-PEG nanoparticles, while clathrin mediated endocytosis was not involved in the endocytosis process. The endocytosed PLA-PEG nanoparticles enriched in the head of A549 cells and only a small amount of them was transported into lysosome after 24h incubation. These findings provided insights into the application of electrosprayed PLA-PEG nanoparticles in nano drug delivery field. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Facile synthesis, spectral properties and formation mechanism of sulfur nanorods in PEG-200

    International Nuclear Information System (INIS)

    Xie, Xin-yuan; Li, Li-yun; Zheng, Pu-sheng; Zheng, Wen-jie; Bai, Yan; Cheng, Tian-feng; Liu, Jie

    2012-01-01

    Graphical abstract: Homogeneous rod-like structure of sulfur with a typical diameter of about 80 nm and an average aspect ratio of about 6–8 was obtained. The sulfur nanoparticles could self-assemble from spherical particles to nanorods in PEG-200. During the self-assembling process, the absorption band showed a red shift which was due to the production of nanorods. Highlights: ► A novel, facile and greener method to synthesize sulfur nanorods by the solubilizing and templating effect of PEG-200 was reported. ► S 0 nanoparticles could self assemble in PEG-200 and finally form monodisperse and homogeneous rod-like structure with an average diameter of about 80 nm, the length ca. 600 nm. ► The absorption band showed a red shift and the RRS intensity enhanced continuously during the self-assembling process. ► PEG-200 induced the oriented attachment of sulfur nanoparticles by the terminal hydroxyl groups. -- Abstract: The synthesis of nano-sulfur sol by dissolving sublimed sulfur in a green solvent-PEG-200 was studied. Homogeneous rod-like structure of sulfur with a typical diameter of about 80 nm and an average aspect ratio of 6–8 was obtained. The structure, morphology, size, and stability of the products were investigated by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) measurements. The spectral properties of the products were investigated by ultraviolet-visible (UV–vis) absorption and resonance Rayleigh scattering spectroscopy (RRS). The results showed that the spherical sulfur nanoparticles could self-assemble into nanorods in PEG-200. During the self-assembling process, the absorption band showed a red shift and the RRS intensity enhanced continuously. There was physical cross-linking between PEG and sulfur nanoparticles. PEG-200 induced the oriented attachment of sulfur nanoparticles by the

  10. Enhancement of light absorption by blood to Nd:YAG laser using PEG-modified gold nanorods.

    Science.gov (United States)

    Xing, Linzhuang; Li, Dong; Chen, Bin; Dai, Yuze; Wu, Wenjuan; Wang, Guoxiang

    2016-10-01

    On the basis of the principle of selective photothermolysis, laser therapy has been the most effective treatment strategy for Port-wine stains (PWSs) caused by the expansion of dermal capillaries. Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser at 1064 nm wavelength has great potential for deeply buried PWS, although its application is limited because of its weak absorption by blood. The purpose of this study is to investigate the effect of PEG-modified gold nanorods (NRs) on the blood absorption enhancement for Nd:YAG laser. PEG-modified gold nanorods (NRs) were synthesized via the seeded growth method. Then, the effect of PEG-modified gold NRs on blood light absorbance was investigated through adding different concentration of PEG-modified gold NRs to 1 ml of blood at room temperature. Finally, the optical properties of whole mice blood with or without PEG-modified gold NRs under slow heating were investigated. The average length and width of PEG-modified gold NRs are 79.5 ± 10.5 and 13.5 ± 0.9 nm, respectively, with the aspect ratio of 5.89, and a strong absorption peak exists at ∼1050 nm in the near-infrared range. A linear correlation between the blood absorbance at 1064 nm and the amount of PEG-modified gold NRs was obtained. The absorbance at 1064 nm increased 17.6, 33.0, 48.3, and 65.4 times when 0.4, 0.8, 1.2, and 1.6 mg of PEG-modified gold NRs was added to 1 ml of blood at room temperature, respectively. After adding 0.8 mg of PEG-modified gold NRs to 1 ml of blood, blood absorbance at 1064 nm at different temperatures increased by an average of 24.0 times. After intravenously injecting PEG-modified gold NRs (0.87 mg/ml) into Sprague-Dawley mice, the blood absorbance at 1064 nm increased from 0.014 to 0.5. Our findings suggest that PEG-modified gold NRs injection is an efficient way to enhance light absorption by blood to Nd:YAG laser. Lasers Surg. Med. 48:790-803, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley

  11. X-ray studies of recombinant anti-testosterone Fab fragments: the use of PEG 3350 in crystallization.

    Science.gov (United States)

    Valjakka, J; Hemminki, A; Teerinen, T; Takkinen, K; Rouvinen, J

    2000-02-01

    Recombinant anti-testosterone wild-type Fab fragment and mutant Fab fragments with high binding selectivity developed by protein engineering have been crystallized with and without ligands. Crystals of these Fab fragments were obtained by the vapour-diffusion technique at room temperature using solutions of PEG 3350 with various biological buffers and with a wide pH range. So far, five data sets have been collected from crystals of three Fab-antigen complexes and from two uncomplexed Fab fragments, with resolutions ranging from 2.10 to 3.1 A. Crystallization conditions for Fab fragments were found by using modifications of the low ionic strength PEG 3350 series. Suitable concentrations of PEG 400, MPD and glycerol solutions for use as cryoprotectants in PEG 3350 solutions have been determined. One useful observation was that PEG 3350 is able to work alone as a cryoprotectant. The screening protocol used requires a smaller amount of protein material to achieve auspicious pre-crystals than previously. Results support the claim that PEG 3350 is more suitable for the crystallization of Fab fragments than higher molecular weight PEGs.

  12. 18F-PEG-biotin: Precursor (boroaryl-PEG-biotin) synthesis, 18F-labelling and an in-vitro assessment of its binding with NeutravidinTM-trastuzumab pre-treated cells

    International Nuclear Information System (INIS)

    Smith, Tim A.D.; Simpson, Michael; Cheyne, Richard; Trembleau, Laurent

    2011-01-01

    In terms of nuclear decay 18 F is the most ideal PET nuclide but its short t 1/2 precludes its use for directly labelling whole antibodies due to their long blood residence times. Pre-targeted imaging using affinity systems such as Neutravidin TM -biotin facilitates the application of short-lived nuclides by their attachment to biotin for imaging cell surface proteins targeted with Neutravidin TM -conjugated antibodies. Methods: Boroaryl functionalised biotin was prepared with a PEG linker and radiolabelled by incubation with 18 F in acidified aqueous solution. Cells expressing high (SKBr3), medium (MDA-MB-453) and low (MDA-MB-468) levels of HER-2 were pre-incubated with Neutravidin TM -conjugated trastuzumab, washed, and then incubated with 18 F-PEG-biotin. Results: The 18 F-fluorination of boroaryl-PEG-biotin was much more efficient than reported for other versions of boroaryl-biotin. The novel 18 F-PEG-biotin was demonstrated to bind to HER-2-expressing cells in-vitro pre-incubated with Neutravidin TM -conjugated trastuzumab. Conclusion: Biotin can be functionalised with boroaryl and readily 18 F-radiolabelled in aqueous solution and will bind to cells pre-incubated with Neutravidin TM -antibody conjugates. - Highlights: → Boroaryl-biotin precursor is prepared. → Rapid 18 F-fluorination is demonstrated. → HER-2 expressing breast cancer cells pre-treated with trastuzumab-Neutravidin TM . → 18 F-PEG-biotin binding to pre-treated cells corresponds with HER-2 expression.

  13. Effect of DSPE-PEG on compound action potential, injury potential and ion concentration following compression in ex vivo spinal cord.

    Science.gov (United States)

    Wang, Aihua; Huo, Xiaolin; Zhang, Guanghao; Wang, Xiaochen; Zhang, Cheng; Wu, Changzhe; Rong, Wei; Xu, Jing; Song, Tao

    2016-05-04

    It has been shown that polyethylene glycol (PEG) can reseal membrane disruption on the spinal cord, but only high concentrations of PEG have been shown to have this effect. Therefore, the effect of PEG is somewhat limited, and it is necessary to investigate a new approach to repair spinal cord injury. This study assesses the ability of 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly (ethylene glycol)) 2000] (DSPE-PEG) to recover physiological function and attenuate the injury-induced influx of extracellular ions in ex vivo spinal cord injury. Isolated spinal cords were subjected to compression injury and treated with PEG or DSPE-PEG immediately after injury. The compound action potential (CAP) was recorded before and after injury to assess the functional recovery. Furthermore, injury potential, the difference in gap potentials before and after compression, and the concentration of intracellular ions were used to evaluate the effect of DSPE-PEG on reducing ion influx. Data showed that the injury potential and ion concentration of the untreated, PEG and DSPE-PEG group, without significant difference among them, are remarkably higher than those of the intact group. Moreover, the CAP recovery of the DSPE-PEG and PEG treated spinal cords was significantly greater than that of the untreated spinal cords. The level of CAP recovery in the DSPE-PEG and PEG treated groups was the same, but the concentration of DSPE-PEG used was much lower than the concentration of PEG. These results suggest that instant application of DSPE-PEG could effectively repair functional disturbance in SCI at a much lower concentration than PEG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Enhancing relative permittivity by incorporating PDMS-PEG multi block copolymers in binary polymer blends

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    Polydimethylsiloxanes (PDMS) are well-known to actuate with relatively large strains due to low modulus, but they possess lowpermittivity. Contrary, polyethyleneglycols (PEG) are not stretchable but possess high permittivity. Combination of the two polymers in a block copolymer depicts a possibil......Polydimethylsiloxanes (PDMS) are well-known to actuate with relatively large strains due to low modulus, but they possess lowpermittivity. Contrary, polyethyleneglycols (PEG) are not stretchable but possess high permittivity. Combination of the two polymers in a block copolymer depicts...... a possibility for substantial improvement of properties such as high permittivity, stretchability and non-conductivity – if carefully designed. The objective is to synthesize PDMS-PEG multiblock copolymer assembling into discontinuous morphologies in PEG based on variation of volume fractions of PDMS....... The utilized synthesis of PDMS-PEG multiblock copolymer is based on hydrosilylation reaction, which is amended from Klasner et al.1 and Jukarainen etal.2 Variation in the ratio between the two constituents introduces distinctive properties in terms of dielectric permittivity and rheological behaviour. PDMS...

  15. PEG IS 40!: place, community, identity, memory and myth in the Dandenong Ranges

    OpenAIRE

    Dyson, Brydie Shae

    2017-01-01

    PEG IS 40! investigates memory, myth and storytelling as well as personal and communal identity with a sense of place, focusing on a particular site, that of the PEG IS 40! inscription on the train bridge in Upper Femtree Gully above Burwood Highway. The text there has not been weathered away, further graffiti has not overwritten it, and it has not been removed by council. In this time of rapid cultural transformation and global pressures, Peg is still and has always been 40. There is a certa...

  16. Buried bumper syndrome revisited: a rare but potentially fatal complication of PEG tube placement.

    Science.gov (United States)

    Biswas, Saptarshi; Dontukurthy, Sujana; Rosenzweig, Mathew G; Kothuru, Ravi; Abrol, Sunil

    2014-01-01

    Percutaneous endoscopic gastrostomy (PEG) has been used for providing enteral access to patients who require long-term enteral nutrition for years. Although generally considered safe, PEG tube placement can be associated with many immediate and delayed complications. Buried bumper syndrome (BBS) is one of the uncommon and late complications of percutaneous endoscopic gastrostomy (PEG) placement. It occurs when the internal bumper of the PEG tube erodes into the gastric wall and lodges itself between the gastric wall and skin. This can lead to a variety of additional complications such as wound infection, peritonitis, and necrotizing fasciitis. We present here a case of buried bumper syndrome which caused extensive necrosis of the anterior abdominal wall.

  17. Mechanically compliant electrodes and dielectric elastomers from PEG-PDMS copolymers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Madsen, Frederikke Bahrt; Skov, Anne Ladegaard

    2016-01-01

    Soft conducting elastomers have been prepared from polydimethylsiloxane-polyethyleneglycol (PDMS-PEG) copolymer and surfactant-stabilized multi-walled carbon nanotubes (MWCNTs). The copolymer was chain-extended with PDMS of molecular weight 17.2 kg mol-1 in order to obtain a crosslinkable PDMS...... showed high conductivity combined with inherent softness. The high conductivity and softness, PDMS-PEG copolymers with incorporated MWCNTs hold great promises as compliant and highly stretchable electrodes for stretchable devices such as electro-mechanical transducers....

  18. Time-Resolved SAXS/WAXS Study of the Phase Behavior and Microstructural Evolution of Drug/PEG Solid Dispersions

    International Nuclear Information System (INIS)

    Zhu, Qing; Harris, Michael T.; Taylor, Lynne S.

    2011-01-01

    Simultaneous small-angle X-ray scattering/wide-angle X-ray scattering (SAXS/WAXS) was employed to elucidate the physical state and location of various small molecule drugs blended with polyethylene glycol (PEG), as well as the time dependent microstructural evolution of the systems. Samples were prepared by comelting physical mixtures of the drug and PEG, followed by solidification at 25 C. The model drugs selected encompassed a wide variety of physicochemical properties in terms of crystallization tendency and potential for interaction with PEG. It was observed that compounds which crystallized rapidly and had weak interactions with PEG tended to be excluded from the interlamellar region of the PEG matrix. In contrast, drugs which had favorable interactions with PEG were incorporated into the interlamellar regions of the polymer up until the point at which the drug crystallized whereby phase separation occurred. These factors are likely to impact the effectiveness of drug/PEG systems as drug delivery systems.

  19. Near-infrared (1550 nm) in vivo bioimaging based on rare-earth doped ceramic nanophosphors modified with PEG-b-poly(4-vinylbenzylphosphonate)

    Science.gov (United States)

    Kamimura, Masao; Kanayama, Naoki; Tokuzen, Kimikazu; Soga, Kohei; Nagasaki, Yukio

    2011-09-01

    A novel poly(ethylene glycol) (PEG)-based block copolymer possessing a 4-vinylbenzylphosphonate repeating unit in another segment (PEG-block-poly(4-vinylbenzylphosphonate)) (PEG-b-PVBP) was designed and successfully synthesized. As a control, an end-functionalized PEG possessing a mono-phosphonate group (PEG-PO3H2) was also synthesized. The surface of near-infrared (NIR) phosphors (i.e., ytterbium (Yb) and erbium (Er) ion-codoped Y2O3 nanoparticles (YNPs)) were modified with PEG-b-PVBP (PEG-YNP(b)s) and PEG-PO3H2 (PEG-YNP(1)s). The adsorption of PEG-b-PVBP and PEG-PO3H2 was estimated by Fourier transform infrared (FT-IR) measurements and thermal gravimetric analysis (TGA). The physicochemical characteristics of the obtained YNP samples were analyzed by ζ-potential and dynamic light scattering (DLS) measurements. The ζ-potentials of YNPs modified by these polymers were close to zero, indicating the effective coverage of the YNP surface by our new PEG derivatives. However, the dispersion stability of the PEGylated YNPs was strongly affected by the structure of the PEG terminus. The average diameter of the PEG-YNP(1)s increased, and aggregates precipitated after less than 1 h in phosphate buffer saline (PBS). In contrast, the size did not change at all in the case of PEG-YNP(b)s and the dispersion in PBS was stable for over 1 week. PEG-YNP(b)s also showed high erosion resistance under acidic conditions. The multiple coordinated PVBP segment of the block copolymer on the YNP surface plays a substantial role in improving such dispersion stability. The excellent dispersion stability and strong NIR luminescence of the obtained PEG-YNP(b)s were also confirmed in fetal bovine serum (FBS) solution over 1 week. Furthermore, in vivo NIR imaging of live mice was performed, and the 1550 nm NIR emission of PEG-YNP(b)s from the organ of live mice was confirmed without dissection.A novel poly(ethylene glycol) (PEG)-based block copolymer possessing a 4-vinylbenzylphosphonate

  20. Request for Observations of V405 Peg

    Science.gov (United States)

    Templeton, Matthew R.

    2009-12-01

    Dr. Axel Schwope (Astrophysikalisches Institut Potsdam) requests time-series monitoring of the magnetic cataclysmic variable V405 Pegasi from 2009 December 28 through 2009 December 30. These observations are requested in support of a planned XMM-Newton observation of V405 Peg on 2009 December 29 beginning at 18:51 UT (JD 2455195.2854) and continuing for 12.5 hours. Observers are asked to provide intensive coverage during the three day window centered on the XMM-Newton observation to provide information on the activity state of V405 Peg, to improve the orbital ephemeris, and to provide optical data that will help constrain the spectral energy distribution of this poorly understood cataclysmic variable. The primary filters for this observation are Johnson B and Cousins I, but all observations will be useful for determining the orbital ephemeris. V405 Peg may show both orbital modulation as well as changes in its activity level. The orbital period is approximately four hours, and observers are asked to obtain at least ten and preferably more data points per cycle in each filter. Please use exposure times that provide S/N of at least 20 in both the comparison and target stars but short exposure times are preferred to detect flickering and other short-timescale variations. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  1. Polyethylene Glycol (PEG-Treated Hydroponic Culture Reduces Length and Diameter of Root Hairs of Wheat Varieties

    Directory of Open Access Journals (Sweden)

    Arif Hasan Khan Robin

    2015-10-01

    Full Text Available Wheat is an important cereal crop worldwide that often suffers from moisture deficits at the reproductive stage. Polyethylene glycol (PEG-treated hydroponic conditions create negative osmotic potential which is compared with moisture deficit stress. An experiment was conducted in a growth chamber to study the effects of PEG on root hair morphology and associated traits of wheat varieties. Plants of 13 wheat varieties were grown hydroponically and three different doses of PEG 6000 (w/v: 0% (control, 0.3% and 0.6% (less than −1 bar were imposed on 60 days after sowing for 20 days’ duration. A low PEG concentration was imposed to observe how initial low moisture stress might affect root hair development. PEG-treated hydroponic culture significantly decreased root hair diameter and length. Estimated surface area reduction of root hairs at the main axes of wheat plants was around nine times at the 0.6% PEG level compared to the control plants. Decrease in root hair diameter and length under PEG-induced culture decreased “potential” root surface area per unit length of main root axis. A negative association between panicle traits, length and dry weight and the main axis length of young roots indicated competition for carbon during their development. Data provides insight into how a low PEG level might alter root hair development.

  2. Difficulties with percutaneous endoscopic gastrostomy (PEG): a practical guide for the endoscopist.

    LENUS (Irish Health Repository)

    O'Mahony, S

    2013-03-01

    Percutaneous endoscopic gastrostomy (PEG) is a widely used and effective means of providing long-term nutrition in patients with inadequate oral intake. The demand for this intervention has risen steadily since the early 1990s. Endoscopists who perform PEG insertion have become increasingly concerned about inappropriate use of this intervention.

  3. The Long-Term Fate and Toxicity of PEG-Modified Single-Walled Carbon Nanotube Isoliquiritigenin Delivery Vehicles in Rats

    Directory of Open Access Journals (Sweden)

    Bo Han

    2014-01-01

    Full Text Available Oxidized single-walled carbon nanotubes (o-SWNTs was modified by covalently and noncovalently linking PEG to the o-SWNTs. The influence of oxidation time, PEG molecular weight, and type of PEG linkage on the blood clearance time of PEG-modified single-walled carbon nanotubes (SWNTs was investigated. The toxicity profile of SWNTs covalently linked to PEG (c-PEG-o-SWNTs in rats has also been determined. The pharmacokinetics of c-PEG-o-SWNTs in rats and their distribution in vital organs were monitored by Raman spectroscopy, and the blood clearance of homogenate isoliquiritigenin (ISL was determined by HPLC. Photos of tissue and tissue sections were taken to evaluate the toxicity of c-PEG-o-SWNTs. We found that SWNTs which were covalently modified with PEG and have a molecular weight of 3500 had the longest blood clearance half-lives. However, SWNTs were toxic to the kidneys and the hearts. The high renal clearance of long-term fate SWNTs may occur because of impaired kidney filtration function. Therefore, we assume that while researchers study the long-term fate of SWNTs, the toxicity of SWNTs also needs to be taken into account.

  4. PEG conjugates in clinical development or use as anticancer agents: an overview.

    Science.gov (United States)

    Pasut, Gianfranco; Veronese, Francesco M

    2009-11-12

    During the almost forty years of PEGylation, several antitumour agents, either proteins, peptides or low molecular weight drugs, have been considered for polymer conjugation but only few entered clinical phase studies. The results from the first clinical trials have shared and improved the knowledge on biodistribution, clearance, mechanism of action and stability of a polymer conjugate in vivo. This has helped to design conjugates with improved features. So far, most of the PEG conjugates comprise of a protein, which in the native form has serious shortcomings that limit the full exploitation of its therapeutic action. The main issues can be short in vivo half-life, instability towards degrading enzymes or immunogenicity. PEGylation proved to be effective in shielding sensitive sites at the protein surface, such as antigenic epitopes and enzymatic degradable sequences, as well as in prolonging the drug half-life by decreasing the kidney clearance. In this review PEG conjugates of proteins or low molecular weight drugs, in clinical development or use as anticancer agents, will be taken into consideration. In the case of PEG-protein derivatives the most represented are depleting enzymes, which act by degrading amino acids essential for cancer cells. Interestingly, PEGylated conjugates have been also considered as adjuvant therapy in many standard anticancer protocols, in this regard the case of PEG-G-CSF and PEG-interferons will be presented.

  5. Distribution and clearance of PEG-single-walled carbon nanotube cancer drug delivery vehicles in mice.

    Science.gov (United States)

    Bhirde, Ashwin A; Patel, Sachin; Sousa, Alioscka A; Patel, Vyomesh; Molinolo, Alfredo A; Ji, Youngmi; Leapman, Richard D; Gutkind, J Silvio; Rusling, James F

    2010-12-01

    To study the distribution and clearance of polyethylene glycol (PEG)-ylated single-walled carbon nanotube (SWCNTs) as drug delivery vehicles for the anticancer drug cisplatin in mice. PEG layers were attached to SWCNTs and dispersed in aqueous media and characterized using dynamic light scattering, scanning transmission electron microscopy and Raman spectroscopy. Cytotoxicity was assessed in vitro using Annexin-V assay, and the distribution and clearance pathways in mice were studied by histological staining and Raman spectroscopy. Efficacy of PEG-SWCNT-cisplatin for tumor growth inhibition was studied in mice. PEG-SWCNTs were efficiently dispersed in aqueous media compared with controls, and did not induce apoptosis in vitro. Hematoxylin and eosin staining, and Raman bands for SWCNTs in tissues from several vital organs from mice injected intravenously with nanotube bioconjugates revealed that control SWCNTs were lodged in lung tissue as large aggregates compared with the PEG-SWCNTs, which showed little or no accumulation. Characteristic SWCNT Raman bands in feces revealed the presence of bilary or renal excretion routes. Attachment of cisplatin on bioconjugates was visualized with Z-contrast scanning transmission electron microscopy. PEG-SWCNT-cisplatin with the attached targeting ligand EGF successfully inhibited growth of head and neck tumor xenografts in mice. PEG-SWCNTs, as opposed to control SWCNTs, form more highly dispersed delivery vehicles that, when loaded with both cisplatin and EGF, inhibit growth of squamous cell tumors.

  6. Mitochondria-targeting cyclometalated iridium(III)-PEG complexes with tunable photodynamic activity.

    Science.gov (United States)

    Li, Steve Po-Yam; Lau, Chris Tsan-Shing; Louie, Man-Wai; Lam, Yun-Wah; Cheng, Shuk Han; Lo, Kenneth Kam-Wing

    2013-10-01

    We present a new class of phosphorescent cyclometalated iridium(III) polypyridine poly(ethylene glycol) (PEG) complexes [Ir(N(^)C)2(bpy-CONH-PEG)](PF6) (bpy-CONH-PEG = 4-(N-(2-(ω-methoxypoly-(1-oxapropyl))ethyl)aminocarbonyl)-4'-methyl-2,2'-bipyridine, number average molecular weight (Mn) = 5272.23, weight average molecular weight (Mw) = 5317.38, polydispersity index (PDI) = 1.009; HN(^)C = 2-phenylpyridine, Hppy (1a), 2-((1,1'-biphenyl)-4-yl)pyridine, Hpppy (2a), 2-phenylquinoline, Hpq (3a), 2-phenylbenzothiazole, Hbt (4a), 2-(1-naphthyl)benzothiazole, Hbsn (5a)). The photophysical, photochemical, and biological properties of these complexes have been compared with those of their PEG-free counterparts [Ir(N(^)C)2(bpy-CONH-Et)](PF6) (bpy-CONH-Et = 4-(N-ethylaminocarbonyl)-4'-methyl-2,2'-bipyridine; HN(^)C = Hppy (1b), Hpppy (2b), Hpq (3b), Hbt (4b), Hbsn (5b)). Upon irradiation, all the complexes exhibited intense and long-lived green to orange-red emission under ambient conditions. The emission was phosphorescence in nature and can be quenched by O2 with the generation of singlet oxygen ((1)O2). The quantum yields for (1)O2 production of the complexes in aerated DMSO (0.24-0.83) were found to be dependent on the excited-state lifetimes of the complexes, which can be altered using different cyclometalating ligands (N(^)C). Cell-based assays indicated that the PEG complexes were noncytotoxic in the dark (IC50 > 300 μM); however, most of them became significantly cytotoxic upon irradiation (IC50 = 3.4 - 23.2 μM). Laser-scanning confocal microscopy images revealed localization of complex 3a in the mitochondrial region of HeLa cells and the induction of rapid necrotic cell death upon light activation. Additionally, the lack of dark toxicity and potential application of the PEG complexes as a visualizing reagent have been demonstrated using zebrafish (Danio rerio) as an animal model. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Endostar-loaded PEG-PLGA nanoparticles: in vitro and in vivo evaluation

    Directory of Open Access Journals (Sweden)

    Sanyuan Hu

    2010-11-01

    Full Text Available Sanyuan Hu1, Yangde Zhang21Xiangya School of Medicine and 2National Hepatobiliary and Enteric Surgery Research Center, Ministry of Health, Central South University, Changsha, Hunan Province, People’s Republic of ChinaAbstract: Endostar, a novel recombinant human endostatin, which was approved by the Chinese State Food and Drug Administration in 2005, has a broad spectrum of activity against solid tumors. In this study, we aimed to determine whether the anticancer effect of Endostar is increased by using a nanocarrier system. It is expected that the prolonged circulation of endostar will improve its anticancer activity. Endostar-loaded nanoparticles were prepared to improve controlled release of the drug in mice and rabbits, as well as its anticancer effects in mice with colon cancer. A protein release system could be exploited to act as a drug carrier. Nanoparticles were formulated from poly (ethylene glycol modified poly (DL-lactide-co-glycolide (PEG-PLGA by a double emulsion technique. Physical and release characteristics of endostar-loaded nanoparticles in vitro were evaluated by transmission electron microscopy (TEM, photon correlation spectroscopy (PCS, and micro bicinchoninic acid protein assay. The pharmacokinetic parameters of endostar nanoparticles in rabbit and mice plasma were measured by enzyme-linked immunosorbent assay. Western blot was used to detect endostatin in different tissues. To study the effects of endostar-loaded nanoparticles in vivo, nude mice in which tumor cells HT-29 were implanted, were subsequently treated with endostar or endostar-loaded PEG-PLGA nanoparticles. Using TEM and PCS, endostar-loaded PEG-PLGA nanoparticles were found to have a spherical core-shell structure with a diameter of 169.56 ± 35.03 nm. Drug-loading capacity was 8.22% ± 2.35% and drug encapsulation was 80.17% ± 7.83%. Compared with endostar, endostar-loaded PEG-PLGA nanoparticles had a longer elimination half-life and lower peak

  8. Upper estimates of complexity of algorithms for multi-peg Tower of Hanoi problem

    Directory of Open Access Journals (Sweden)

    Sergey Novikov

    2007-06-01

    Full Text Available There are proved upper explicit estimates of complexity of lgorithms: for multi-peg Tower of Hanoi problem with the limited number of disks, for Reve's puzzle and for $5$-peg Tower of Hanoi problem with the free number of disks.

  9. In situ forming poly(ethylene glycol)- Poly(L -lactide) hydrogels via michael addition: Mechanical properties, degradation, and protein release

    NARCIS (Netherlands)

    Buwalda, S.J.; Dijkstra, Pieter J.; Feijen, Jan

    2012-01-01

    Chemically crosslinked hydrogels are prepared at remarkably low macromonomer concentrations from 8-arm poly(ethylene glycol)-poly(L-lactide) star block copolymers bearing acrylate end groups (PEG-(PLLAn)8-AC, n = 4 or 12) and multifunctional PEG thiols (PEG-(SH)n, n = 2, 4, or 8) through a

  10. Cholesterol-PEG comodified poly (N-butyl) cyanoacrylate nanoparticles for brain delivery: in vitro and in vivo evaluations.

    Science.gov (United States)

    Hu, Xiao; Yang, Feifei; Liao, Yonghong; Li, Lin; Zhang, Lan

    2017-11-01

    This study investigated cholesterol-polyethylene glycol (PEG) comodified poly (ethyleneglycol)-poly (lactide) nanoparticles (CLS-PEG NPs) as a novel, biodegradable brain drug delivery system and included an evaluation of its in vitro and in vivo properties. To this end, coumarin-6 (C6), a fluorescent probe, was encapsulated into CLS-PEG NPs by an emulsion polymerization method. We reported that the use of CLS-PEG NPs led to a sustained drug release in vitro. Additionally, cell viability experiments confirmed their safety. The uptake and transport of CLS-PEG NPs, by bEnd.3 cells (an immortalized mouse brain endothelial cell line), was significantly higher than that of a control C6 solution. An investigation of the uptake mechanisms of different NP formulations demonstrated that cholesterol modifications may be the primary way to improve the efficiency of cellular uptake, wherein macropinocytosis may be the most important endocytic pathway in this process. An investigation of the transport mechanisms of CLS-PEG NPs also implicated macropinocytosis, energy and cholesterol in bEnd.3 cells lines. Following an intravenous (IV) administration to rats, pharmacokinetic experiments indicated that C6-loaded CLS-PEG NPs achieved sustained release for up to 12 h. In addition, IV delivery of CLS-PEG NPs appeared to significantly improve the ability of C6 to pass through the blood-brain barrier: the concentration of C6 found in the brain increased nearly 14.2-fold when C6 CLS-PEG NPs were used rather than a C6 solution. These in vitro and in vivo results strongly suggest that CLS-PEG NPs are a promising drug delivery system for targeting the brain, with low toxicity.

  11. Effect of PEG-PDLLA polymeric nanovesicles loaded with doxorubicin and hematoporphyrin monomethyl ether on human hepatocellular carcinoma HepG2 cells in vitro

    Directory of Open Access Journals (Sweden)

    Xiang GH

    2013-12-01

    Full Text Available Guang-Hua Xiang,1,2,* Guo-Bin Hong,2,3,* Yong Wang,2 Du Cheng,2 Jing-Xing Zhou,1 Xin-Tao Shuai21Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, People's Republic of China; 2PCFM Laboratory of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, People's Republic of China; 3Department of Radiology, Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, People's Republic of China*These two authors contributed equally to this workObjective: To evaluate the cytotoxicity of poly(ethylene glycol-block-poly(D,L-lactic acid (PEG-PDLLA nanovesicles loaded with doxorubicin (DOX and the photosensitizer hematoporphyrin monomethyl ether (HMME on human hepatocellular carcinoma HepG2 cells and to investigate potential apoptotic mechanisms.Methods: PEG-PDLLA nanovesicles were simultaneously loaded with DOX and HMME (PEG-PDLLA-DOX-HMME, and PEG-PDLLA nanovesicles were loaded with DOX (PEG-PDLLA-DOX, HMME (PEG-PDLLA-HMME, or the PEG-PDLLA nanovesicle alone as controls. The cytotoxicity of PEG-PDLLA-DOX-HMME, PEG-PDLLA-DOX, PEG-PDLLA-HMME, and PEG-PDLLA against HepG2 cells was measured, and the cellular reactive oxygen species, percentage of cells with mitochondrial membrane potential depolarization, and apoptotic rate following treatment were determined.Results: Four nanovesicles (PEG-PDLLA-DOX-HMME, PEG-PDLLA-DOX, PEG-PDLLA-HMME, and PEG-PDLLA were synthesized, and mean particle sizes were 175±18 nm, 154±3 nm, 196±2 nm, and 147±15 nm, respectively. PEG-PDLLA-DOX-HMME was more cytotoxic than PEG-PDLLA-DOX, PEG-PDLLA-HMME, and PEG-PDLLA. PEG-PDLLA-HMME-treated cells had the highest mean fluorescence intensity, followed by PEG-PDLLA-DOX-HMME-treated cells, whereas PEG-PDLLA-DOX- and PEG-PDLLA-treated cells had a similar fluorescence intensity. Mitochondrial membrane potential depolarization was observed in 54.2%, 59.4%, 13.8%, and 14.8% of the cells treated with

  12. Intra-articular Administration of Chitosan Thermosensitive In Situ Hydrogels Combined With Diclofenac Sodium-Loaded Alginate Microspheres.

    Science.gov (United States)

    Qi, Xiaole; Qin, Xiaoxue; Yang, Rong; Qin, Jiayi; Li, Wenyan; Luan, Kun; Wu, Zhenghong; Song, Li

    2016-01-01

    The aims of this study were to prepare fine intra-articular-administrated chitosan thermosensitive hydrogels combined with alginate microspheres and to investigate the possibility of those hydrogels as a drug delivery system for promoting the anti-inflammation effect. Diclofenac sodium containing alginate microspheres was prepared by a modified emulsification and/or gelation method and then dispersed into injectable thermosensitive hydrogels, consisting of chitosan and β-glycerophosphate. The final combined hydrogels were evaluated in terms of their morphology properties, rheological properties, in vitro drug release, and in vivo biocompatibility and pharmacodynamics behaviors. The optimized formulation exhibited sol-gel transition at 31.72 ± 0.42°C and quickly turned into gel within 5 min, with sustained drug release characteristics followed Ritger-Peppas equation, which could prolong the in vitro drug release to 5 days. In addition, the anti-inflammation efficacy of the combined hydrogels in rabbits with experimental rheumatoid arthritis was higher than that of drug solution and pure chitosan hydrogels. Those results demonstrated that these combined hydrogels could become a potential drug delivery system for improving the therapeutic effect of diclofenac sodium and suggested an important technology platform for intra-articular administration. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Development and characterization of chitosan-PEG-TAT nanoparticles for the intracellular delivery of siRNA

    Directory of Open Access Journals (Sweden)

    Malhotra M

    2013-05-01

    Full Text Available Meenakshi Malhotra,1 Catherine Tomaro-Duchesneau,1 Shyamali Saha,2 Imen Kahouli,3 Satya Prakash11Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering, Faculty of Medicine, 2Faculty of Dentistry, 3Department of Experimental Medicine, McGill University, Montreal, QC, CanadaAbstract: Recently, cell-penetrating peptides have been proposed to translocate antibodies, proteins, and other molecules in targeted drug delivery. The proposed study presents the synthesis and characterization of a peptide-based chitosan nanoparticle for small interfering RNA (siRNA delivery, in-vitro. Specifically, the synthesis included polyethylene glycol (PEG, a hydrophilic polymer, and trans-activated transcription (TAT peptide, which were chemically conjugated on the chitosan polymer. The conjugation was achieved using N-Hydroxysuccinimide-PEG-maleimide (heterobifunctional PEG as a cross-linker, with the bifunctional PEG facilitating the amidation reaction through its N-Hydroxysuccinimide group and reacting with the amines on chitosan. At the other end of PEG, the maleimide group was chemically conjugated with the cysteine-modified TAT peptide. The degree of substitution on chitosan with PEG and on PEG with TAT was confirmed using colorimetric assays. The resultant polymer was used to form nanoparticles complexing siRNA, which were then characterized for particle size, morphology, cellular uptake, and cytotoxicity. The nanoparticles were tested in-vitro on mouse neuroblastoma cells (Neuro2a. Particle size and surface charge were characterized and an optimal pH condition and PEG molecular weight were determined to form sterically stable nanoparticles. Results indicate 7.5% of the amines in chitosan polymer were conjugated to the PEG and complete conjugation of TAT peptide was observed on the synthesized PEGylated chitosan polymer. Compared with unmodified chitosan nanoparticles, the nanoparticles formed at pH 6 were

  14. Use of read-across and computer-based predictive analysis for the safety assessment of PEG cocamines.

    Science.gov (United States)

    Skare, Julie A; Blackburn, Karen; Wu, Shengde; Re, Thomas A; Duche, Daniel; Ringeissen, Stephanie; Bjerke, Donald L; Srinivasan, Viny; Eisenmann, Carol

    2015-04-01

    In the European Union animal testing has been eliminated for cosmetic ingredients while the US Cosmetic Ingredient Review Expert Panel may request data from animal studies. The use of read-across and predictive toxicology provides a path for filling data gaps without additional animal testing. The PEG cocamines are tertiary amines with an alkyl group derived from coconut fatty acids and two PEG chains of varying length. Toxicology data gaps for the PEG cocamines can be addressed by read-across based on structure-activity relationship using the framework described by Wu et al. (2010) for identifying suitable structural analogs. Data for structural analogs supports the conclusion that the PEG cocamines are non-genotoxic and not expected to exhibit systemic or developmental/reproductive toxicity with use in cosmetics. Due to lack of reliable dermal sensitization data for suitable analogs, this endpoint was addressed using predictive software (TIMES SS) as a first step (Laboratory of Mathematical Chemistry). The prediction for PEG cocamines was the same as that for PEGs, which have been concluded to not present a significant concern for dermal sensitization. This evaluation for PEG cocamines demonstrates the utility of read-across and predictive toxicology tools to assess the safety of cosmetic ingredients. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. A Functional Iron Oxide Nanoparticles Modified with PLA-PEG-DG as Tumor-Targeted MRI Contrast Agent.

    Science.gov (United States)

    Xiong, Fei; Hu, Ke; Yu, Haoli; Zhou, Lijun; Song, Lina; Zhang, Yu; Shan, Xiuhong; Liu, Jianping; Gu, Ning

    2017-08-01

    Tumor targeting could greatly promote the performance of magnetic nanomaterials as MRI (Magnetic Resonance Imaging) agent for tumor diagnosis. Herein, we reported a novel magnetic nanoparticle modified with PLA (poly lactic acid)-PEG (polyethylene glycol)-DG (D-glucosamine) as Tumor-targeted MRI Contrast Agent. In this work, we took use of the D-glucose passive targeting on tumor cells, combining it on PLA-PEG through amide reaction, and then wrapped the PLA-PEG-DG up to the Fe 3 O 4 @OA NPs. The stability and anti phagocytosis of Fe 3 O 4 @OA@PLA-PEG-DG was tested in vitro; the MRI efficiency and toxicity was also detected in vivo. These functional magnetic nanoparticles demonstrated good biocompatibility and stability both in vitro and in vivo. Cell experiments showed that Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles exist good anti phagocytosis and high targetability. In vivo MRI images showed that the contrast effect of Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles prevailed over the commercial non tumor-targeting magnetic nanomaterials MRI agent at a relatively low dose. The DG can validly enhance the tumor-targetting effect of Fe 3 O 4 @OA@PLA-PEG nanoparticle. Maybe MRI agents with DG can hold promise as tumor-targetting development in the future.

  16. Hydrogel Macroporosity and the Prolongation of Transgene Expression and the Enhancement of Angiogenesis

    Science.gov (United States)

    Shepard, Jaclyn A.; Virani, Farrukh R.; Goodman, Ashley G.; Gossett, Timothy D.; Shin, Seungjin; Shea, Lonnie D.

    2012-01-01

    The utility of hydrogels for regenerative medicine can be improved through localized gene delivery to enhance their bioactivity. However, current systems typically lead to low-level transgene expression located in host tissue surrounding the implant. Herein, we investigated the inclusion of macropores into hydrogels to facilitate cell ingrowth and enhance gene delivery within the macropores in vivo. Macropores were created within PEG hydrogels by gelation around gelatin microspheres, with gelatin subsequently dissolved by incubation at 37°C. The macropores were interconnected, as evidenced by homogeneous cell seeding in vitro and complete cell infiltration in vivo. Lentivirus loaded within hydrogels following gelation retained its activity relative to the unencapsulated control virus. In vivo, macroporous PEG demonstrated sustained, elevated levels of transgene expression for 6 weeks, while hydrogels without macropores had transient expression. Transduced cells were located throughout the macroporous structure, while non-macroporous PEG hydrogels had transduction only in the adjacent host tissue. Delivery of lentivirus encoding for VEGF increased vascularization relative to the control, with vessels throughout the macropores of the hydrogel. The inclusion of macropores within the hydrogel to enhance cell infiltration enhances transduction and influences tissue development, which has implications for multiple regenerative medicine applications. PMID:22800542

  17. Lack of lasting effectiveness of PEG 3350 laxative treatment of constipation.

    Science.gov (United States)

    Tran, Lily C; Di Palma, Jack A

    2005-08-01

    PEG 3350 (MiraLax, Braintree Laboratories Inc., Braintree, MA) 17 g daily has been shown to be safe and effective in a 14-day trial for constipation. This present investigation was designed to extend the treatment and safety experience with PEG 3350 and to evaluate any lasting effectiveness during a 30-day post-treatment observation period. Study subjects met Rome II criteria for constipation and reported PEG 3350 17 g daily for 14 days. Treatment efficacy was defined by resolution of constipation symptoms as determined by the Rome II and stool frequency definitions during the treatment period. Fifty healthy constipated subjects formed the study group. There were 42 females and 8 males. Mean age was 52 +/- 15.5 years (+/-SD). Symptom duration was 22.6 +/- 16.7 months (+/-SD). At baseline, all had 3 stools in the last week and no longer met Rome criteria. Thirty-two of 45 (71.1%) reported satisfaction with the first bowel movement after initiating treatment. Thirty days after active treatment, 29 of 47 (61.7%) responded that they needed laxative treatment. PEG 3350 relieved constipation in most treated study subjects. During a 30-day post-treatment observation period, 29 of 47 (61.7%) had additional constipation treatment interventions.

  18. Biomedical applications of SPION@APTES@PEG-folic acid@carboxylated quercetin nanodrug on various cancer cells

    International Nuclear Information System (INIS)

    Akal, Z.Ü.; Alpsoy, L.; Baykal, A.

    2016-01-01

    Highlights: • SPION has been synthesized via Reflux synthesis route. • SPION@APTES@FA-PEG@CQ nanodrug has super paramagnetic property. • SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 cells. • SPION@APTES@FA-PEG@CQ nanodrug can be potentially used for the delivery of quercetin to cervical and breast cancer cells. - Abstract: In this study, carboxylated quercetin (CQ) was conjugated to superparamagnetic iron oxide nanoparticles (SPIONs) which were modified by (3-aminopropyl) triethoxysilane (APTES), Folic acid (FA) and carboxylated Polyethylene glycol (PEG); (SPION@APTES@FA-PEG@CQ), nanodrug has been synthesized via polyol and accompanying by various chemical synthesis routes. The characterization of the final product was done via X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), Transmission electron spectroscopy (TEM) and Vibrating sample magnetometer (VSM). Its cytotoxic and apoptotic activities on over expressed folic acid receptor (FR + ) (MCF-7, HeLa) and none expressed folic acid receptor (FR-) (A549) cancer cell lines were determined by using MTT assay, Real-Time Cell Analysis, TUNEL assay, Annexin assay and RT-PCR analysis for Caspase3/7 respectively. SPION@APTES@FA-PEG@CQ nanodrug showed higher cytotoxicity against HeLa and MCF-7 cell lines as compared with A549 cell line. Moreover, SPION@APTES@FA-PEG@CQ nanodrug also caused higher apoptotic and necrotic effects in 100 μg/mL HeLa and MCF-7 cells than A549 cells. The findings showed that SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 which are FR over expressed cell lines and can be potentially used for the delivery of quercetin to cervical and breast cancer cells.

  19. Biomedical applications of SPION@APTES@PEG-folic acid@carboxylated quercetin nanodrug on various cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Akal, Z.Ü., E-mail: zulker@fatih.edu.tr [Department of Biology, 34500 Büyükçekmece, Istanbul (Turkey); Alpsoy, L. [Department of Biology, 34500 Büyükçekmece, Istanbul (Turkey); Department of Medical Biology, 34500 Büyükçekmece, Istanbul (Turkey); Baykal, A. [Department of Chemistry, Fatih University, 34500 Büyükçekmece, Istanbul (Turkey)

    2016-08-15

    Highlights: • SPION has been synthesized via Reflux synthesis route. • SPION@APTES@FA-PEG@CQ nanodrug has super paramagnetic property. • SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 cells. • SPION@APTES@FA-PEG@CQ nanodrug can be potentially used for the delivery of quercetin to cervical and breast cancer cells. - Abstract: In this study, carboxylated quercetin (CQ) was conjugated to superparamagnetic iron oxide nanoparticles (SPIONs) which were modified by (3-aminopropyl) triethoxysilane (APTES), Folic acid (FA) and carboxylated Polyethylene glycol (PEG); (SPION@APTES@FA-PEG@CQ), nanodrug has been synthesized via polyol and accompanying by various chemical synthesis routes. The characterization of the final product was done via X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), Transmission electron spectroscopy (TEM) and Vibrating sample magnetometer (VSM). Its cytotoxic and apoptotic activities on over expressed folic acid receptor (FR + ) (MCF-7, HeLa) and none expressed folic acid receptor (FR-) (A549) cancer cell lines were determined by using MTT assay, Real-Time Cell Analysis, TUNEL assay, Annexin assay and RT-PCR analysis for Caspase3/7 respectively. SPION@APTES@FA-PEG@CQ nanodrug showed higher cytotoxicity against HeLa and MCF-7 cell lines as compared with A549 cell line. Moreover, SPION@APTES@FA-PEG@CQ nanodrug also caused higher apoptotic and necrotic effects in 100 μg/mL HeLa and MCF-7 cells than A549 cells. The findings showed that SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 which are FR over expressed cell lines and can be potentially used for the delivery of quercetin to cervical and breast cancer cells.

  20. The effectiveness of polyethylene glycol (PEG) and polyvinyl ...

    African Journals Online (AJOL)

    mahlos

    2012-05-29

    May 29, 2012 ... Key words: Acetone, tannin, polyethylene glycol (PEG), polyvinyl polypyrrolidone (PVPP). ... hydrolysable tannins may occur in the same plant. ..... Rev. Food Sci. Nutr., 38: 421-464. Cornell. (2000). Tannins: Chemical analysis.

  1. DNA psi-condensation and reentrant decondensation: Effect of the PEG degree of polymerization

    NARCIS (Netherlands)

    Ramos, J.E.B.; Vries, de R.J.; Neto, J.R.

    2005-01-01

    ¿-Condensation of DNA fragments of about 4 kbp was induced by poly(ethylene glycol) (PEG), with degrees of polymerization ranging from 45 to 182, and univalent salt (NaCl). Using circular dichroism spectroscopy, we were able to accurately determine the critical amount of PEG needed to induce

  2. The optimal currency-peg for an oil exporting country: The case of Saudi Arabia

    International Nuclear Information System (INIS)

    Almasbahi, M.S.

    1990-01-01

    In a world of generalized floating exchange rates, it is not enough to solve the problem of exchange rate policy by determining whether to peg or float the currency under consideration. It is also necessary to choose to what major currency to peg. The main purpose of this study is to investigate and determine empirically the optimum currency peg for the Saudi riyal. To accomplish this goal, a simple conventional trade model, that includes variables found in many other studies of import and export demand, was used. In addition, an exchange rate term was added as a separate independent variable in the import and export demand equations in order to assess the effect of exchange rate on the trade flows. The criteria for the optimal currency peg in this study were based on two factors. First, the error statistics for projected imports and exports using alternative exchange rate regimes. Second, variances of projected imports, exports and trade balance using alternative exchange rate regimes. The exchange rate has a significant impact on the Saudia Arabian trade flows which implies that changes in the riyals value affect the Saudi trade deficit. Moreover, the exchange rate has a more powerful effect on its aggregate imports than on the world demand for its exports. There is also a strong support for the hypothesis that the exchange rate affects the value of the Saudi bilateral trade with its five major trade partners. On the aggregate level, the SDR peg seems to be the best currency peg for the Saudi riyal since it provides the best prediction errors and the lowest variance for the trade balance. Finally, on the disaggregate level, the US dollar provides the best performance and yields the best results among all the six currency pegs considered in this study

  3. The Influence of PEG400 and Acetone on Polysulfone Membrane Morphology and Fouling Behaviour

    Directory of Open Access Journals (Sweden)

    P.T.P. Aryanti

    2016-05-01

    Full Text Available Modification of polysulfone ultrafiltration membrane was conducted by blending polysulfone with PEG400 and acetone as additives. The influence of each additive on the resulted membrane morphology and fouling characteristics were investigated. The experimental results showed that the hydrophilicity of the polysulfone membrane was improved by the increase of PEG400 in the polysulfone membrane. The water contact angle of the membrane was decreased from 76.1° to 38.31° when 35 %wt of PEG400 was added into the polysulfone solution, while the water content of the membrane was increased by around 38%. The high concentration of PEG400 in the polysulfone solution led to the formation of longer finger-like cavities in the membrane structure and resulted in a thicker membrane skin layer. The high concentration of PEG400 also contributed to the increase in hydraulic resistance of the membrane due to organic matter fouling. This problem could be minimized by the addition of acetone into the polysulfone solution, which resulted in a lower fouling resistance of organic matter during up to five hours of peat water filtration.

  4. Enhancing relative permittivity by incorporating PDMS-PEG multiblock copolymers in binary polymer blends

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    Polydimethylsiloxane (PDMS) elastomers are well-known to be soft and highly stretchable, yet they never achieve maximum elongation when utilised as dielectric elastomers, simply because their dielectric permittivity remains rather low. Conversely, polyethyleneglycols (PEG) are not stretchable......, but they do possess high permittivity. Combining two such polymers in a block copolymer allows for further crosslinking and presents the possibility of substantial improvements in the actuation response of the resulting dielectric elastomer – if carefully designed. The objective is to synthesise a PDMS......, the discontinuity in PEG can be acquired and the relative permittivity (ε’) is significantly enhanced (60%) with 5wt% of PDMS-PEG block copolymer incorporated into the silicone elastomer....

  5. Exosome purification based on PEG-coated Fe3O4 nanoparticles.

    Science.gov (United States)

    Chang, Ming; Chang, Yaw-Jen; Chao, Pei Yu; Yu, Qing

    2018-01-01

    Cancer cells secrete many exosomes, which facilitate metastasis and the later growth of cancer. For early cancer diagnosis, the detection of exosomes is a crucial step. Exosomes exist in biological fluid, such as blood, which contains various proteins. It is necessary to remove the proteins in the biological fluid to avoid test interference. This paper presented a novel method for exosome isolation using Fe3O4 magnetic nanoparticles (MNPs), which were synthesized using the chemical co-precipitation method and then coated with polyethylene glycol (PEG). The experimental results showed that the diameter of the PEG-coated Fe3O4 nanoparticles was about 20 nm, while an agglomerate of MNPs reached hundreds of nanometers in size. In the protein removal experiments, fetal bovine serum (FBS) was adopted as the analyte for bioassays of exosome purification. PEG-coated Fe3O4 MNPs reduced the protein concentration in FBS to 39.89% of the original solution. By observing a particle size distribution of 30~200 nm (the size range of various exosomes), the exosome concentrations were kept the same before and after purification. In the gel electrophoresis experiments, the bands of CD63 (~53 kDa) and CD9 (~22 kDa) revealed that exosomes existed in FBS as well as in the purified solution. However, the bands of the serum albumins (~66 kDa) and the various immunoglobulins (around 160 ~ 188 kDa) in the purified solution's lane explained that most proteins in FBS were removed by PEG-coated Fe3O4 MNPs. When purifying exosomes from serum, protein removal is critical for further exosome investigation. The proposed technique provides a simple and effective method to remove proteins in the serum using the PEG-coated Fe3O4 MNPs.

  6. Polyethylene Glycol (PEG-3350, Colyte Poisoning due to Intra-Peritoneal Leakage in an Elderly Patient

    Directory of Open Access Journals (Sweden)

    Jae Hee Chung

    Full Text Available Polyethylene glycol (PEG-3350 is the most frequently used lavage solution for bowel cleansing prior to colonoscopy or elective surgery because its large molecular weight means that it is poorly absorbed. However, if it leaks into the peritoneal cavity, complications may arise. Few published studies have assessed the absorption, distribution, metabolism and excretion of PEG. Moreover, no published clinical data regarding complications due to the intra-peritoneal leakage of PEG-3350 could be found. We report on an elderly patient who developed the poisoning caused by leaking of PEG-3350 during bowel preparation. It resulted in severe metabolic acidosis, hypernatremia, hyperosmolality and a high anion gap, but it was effectively treated with early continuous renal replacement therapy after surgery.

  7. Targeted PEG-based bioconjugates enhance the cellular uptake and transport of a HIV-1 TAT nonapeptide.

    Science.gov (United States)

    Ramanathan, S; Qiu, B; Pooyan, S; Zhang, G; Stein, S; Leibowitz, M J; Sinko, P J

    2001-12-13

    We previously described the enhanced cell uptake and transport of R.I-K(biotin)-Tat9, a large ( approximately 1500 Da) peptidic inhibitor of HIV-1 Tat protein, via SMVT, the intestinal biotin transporter. The aim of the present study was to investigate the feasibility of targeting biotinylated PEG-based conjugates to SMVT in order to enhance cell uptake and transport of Tat9. The 29 kDa peptide-loaded bioconjugate (PEG:(R.I-Cys-K(biotin)-Tat9)8) used in these studies contained eight copies of R.I-K(biotin)-Tat9 appended to PEG by means of a cysteine linkage. The absorptive transport of biotin-PEG-3400 (0.6-100 microM) and the bioconjugate (0.1-30 microM) was studied using Caco-2 cell monolayers. Inhibition of biotin-PEG-3400 by positive controls (biotin, biocytin, and desthiobiotin) was also determined. Uptake of these two compounds was also determined in CHO cells transfected with human SMVT (CHO/hSMVT) and control cells (CHO/pSPORT) over the concentration ranges of 0.05-12.5 microM and 0.003-30 microM, respectively. Nonbiotinylated forms of these two compounds, PEG-3350 and PEG:(R.I-Cys-K-Tat9)8, were used in the control studies. Biotin-PEG-3400 transport was found to be concentration-dependent and saturable in Caco-2 cells (K(m)=6.61 microM) and CHO/hSMVT cells (K(m)=1.26 microM). Transport/uptake was significantly inhibited by positive control substrates of SMVT. PEG:(R.I-Cys-K(biotin)Tat9)8 also showed saturable transport kinetics in Caco-2 cells (K(m)=6.13 microM) and CHO/hSMVT cells (K(m)=8.19 microM). Maximal uptake in molar equivalents of R.I-Cys-K(biotin)Tat9 was 5.7 times greater using the conjugate versus the biotinylated peptide alone. Transport of the nonbiotinylated forms was significantly lower (PPEG-3400 and PEG:(R.I-Cys-K(biotin)Tat9)8 interact with human SMVT to enhance the cellular uptake and transport of these larger molecules and that targeted bioconjugates may have potential for enhancing the cellular uptake and transport of small peptide

  8. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder

    Science.gov (United States)

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; Duross, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G.; Heiser, Laura M.; Korolchuk, Viktor I.; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-08-01

    2-Hydroxy-propyl-β-cyclodextrin (HPβCD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HPβCD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (ethylene glycol) (PEG)-lipid conjugate enables cholesterol clearance from endo/lysosomes of Npc1 mutant (Npc1-/-) cells. Herein, we show that distearyl-phosphatidylethanolamine-PEG (DSPE-PEG), which forms 12-nm micelles above the critical micelle concentration, accumulates heavily inside cholesterol-rich late endosomes in Npc1-/- cells. This potentially results in cholesterol solubilization and leakage from lysosomes. High-throughput screening revealed that DSPE-PEG, in combination with HPβCD, acts synergistically to efflux cholesterol without significantly aggravating autophagy defects. These well-known excipients can be used as admixtures to treat NPC1 disorder. Increasing PEG chain lengths from 350 Da-30 kDa in DSPE-PEG micelles, or increasing DSPE-PEG content in an array of liposomes packaged with HPβCD, improved cholesterol egress, while Pluronic block copolymers capable of micelle formation showed slight effects at high concentrations. We postulate that PEG-lipid based nanocarriers can serve as bioactive drug delivery systems for effective treatment of lysosomal storage disorders.

  9. PEG-lipid micelles enable cholesterol efflux in Niemann-Pick Type C1 disease-based lysosomal storage disorder

    Science.gov (United States)

    Brown, Anna; Patel, Siddharth; Ward, Carl; Lorenz, Anna; Ortiz, Mauren; DuRoss, Allison; Wieghardt, Fabian; Esch, Amanda; Otten, Elsje G.; Heiser, Laura M.; Korolchuk, Viktor I.; Sun, Conroy; Sarkar, Sovan; Sahay, Gaurav

    2016-01-01

    2-Hydroxy-propyl-β-cyclodextrin (HPβCD), a cholesterol scavenger, is currently undergoing Phase 2b/3 clinical trial for treatment of Niemann Pick Type C-1 (NPC1), a fatal neurodegenerative disorder that stems from abnormal cholesterol accumulation in the endo/lysosomes. Unfortunately, the extremely high doses of HPβCD required to prevent progressive neurodegeneration exacerbates ototoxicity, pulmonary toxicity and autophagy-based cellular defects. We present unexpected evidence that a poly (ethylene glycol) (PEG)-lipid conjugate enables cholesterol clearance from endo/lysosomes of Npc1 mutant (Npc1−/−) cells. Herein, we show that distearyl-phosphatidylethanolamine-PEG (DSPE-PEG), which forms 12-nm micelles above the critical micelle concentration, accumulates heavily inside cholesterol-rich late endosomes in Npc1−/− cells. This potentially results in cholesterol solubilization and leakage from lysosomes. High-throughput screening revealed that DSPE-PEG, in combination with HPβCD, acts synergistically to efflux cholesterol without significantly aggravating autophagy defects. These well-known excipients can be used as admixtures to treat NPC1 disorder. Increasing PEG chain lengths from 350 Da-30 kDa in DSPE-PEG micelles, or increasing DSPE-PEG content in an array of liposomes packaged with HPβCD, improved cholesterol egress, while Pluronic block copolymers capable of micelle formation showed slight effects at high concentrations. We postulate that PEG-lipid based nanocarriers can serve as bioactive drug delivery systems for effective treatment of lysosomal storage disorders. PMID:27572704

  10. Thermo-sensitive nanoparticles for triggered release of siRNA.

    Science.gov (United States)

    Yang, Zheng; Cheng, Qiang; Jiang, Qian; Deng, Liandong; Liang, Zicai; Dong, Anjie

    2015-01-01

    Efficient delivery of small interfering RNA (siRNA) is crucially required for cancer gene therapy. Herein, a thermo-sensitive copolymer with a simple structure, poly (ethylene glycol) methyl ether acrylate-b-poly (N-isopropylacrylamide) (mPEG-b-PNIPAM) was developed. A novel kind of thermo-sensitive nanoparticles (DENPs) was constructed for the cold-shock triggered release of siRNA by double emulsion-solvent evaporation method using mPEG-b-PNIPAM and a cationic lipid, 3β [N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol [DC-Chol]. DENPs were observed by transmission electron microscopy and dynamical light scattering before and after 'cold shock' treatment. The encapsulation efficiency (EE) of siRNA in DENPs, which was measured by fluorescence spectrophotometer was 96.8% while it was significantly reduced to be 23.2% when DC-Chol was absent. DENPs/siRNA NPs exhibited a thermo-sensitive siRNA release character that the cumulatively released amount of siRNA from cold shock was approximately 2.2 folds higher after 7 days. In vitro luciferase silencing experiments indicated that DENPs showed potent gene silencing efficacy in HeLa-Luc cells (HeLa cells steadily expressed luciferase), which was further enhanced by a cold shock. Furthermore, MTT assay showed that cell viability with DENPs/siRNA up to 200 nM remained above 80%. We also observed that most of siRNA was accumulated in kidney mediated by DENPs instead of liver and spleen in vivo experiments. Thus, DENPs as a cold shock responsive quick release model for siRNA or hydrophilic macromolecules delivery provide a new way to nanocarrier design and clinic therapy.

  11. A Versatile Star PEG Grafting Method for the Generation of Nonfouling and Nonthrombogenic Surfaces

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Thalla

    2013-01-01

    Full Text Available Polyethylene glycol (PEG grafting has a great potential to create nonfouling and nonthrombogenic surfaces, but present techniques lack versatility and stability. The present work aimed to develop a versatile PEG grafting method applicable to most biomaterial surfaces, by taking advantage of novel primary amine-rich plasma-polymerized coatings. Star-shaped PEG covalent binding was studied using static contact angle, X-ray photoelectron spectroscopy (XPS, and quartz crystal microbalance with dissipation monitoring (QCM-D. Fluorescence and QCM-D both confirmed strong reduction of protein adsorption when compared to plasma-polymerized coatings and pristine poly(ethyleneterephthalate (PET. Moreover, almost no platelet adhesion was observed after 15 min perfusion in whole blood. Altogether, our results suggest that primary amine-rich plasma-polymerized coatings offer a promising stable and versatile method for PEG grafting in order to create nonfouling and nonthrombogenic surfaces and micropatterns.

  12. Optimization of PEG-based extraction of polysaccharides from Dendrobium nobile Lindl. and bioactivity study.

    Science.gov (United States)

    Zhang, Yi; Wang, Hongxin; Wang, Peng; Ma, ChaoYang; He, GuoHua; Rahman, Md Ramim Tanver

    2016-11-01

    Polyethylene glycol (PEG) as a green solvent was employed to extract polysaccharide. The optimal conditions for PEG-based ultrasonic extraction of Dendrobium nobile Lindl. polysaccharide (JCP) were determined by response surface methodology. Under the optimal conditions: extraction temperature of 58.5°C; ultrasound power of 193W, and the concentration of polyethylene glycol-200 (PEG-200) solution of 45%, the highest JCP yield was obtained as 15.23±0.57%, which was close to the predicted yield, 15.57%. UV and FT-IR analysis revealed the general characteristic absorption peaks of both JCP with water extraction (JCP w ) and PEG-200 solvent extraction (JCP p ). Thermal analysis of both JCPs was performed with Thermal Gravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC). Antioxidant activities of two polysaccharides were also compared and no significant difference in vitro was obtained. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Chemical peeling by SA-PEG remodels photo-damaged skin: suppressing p53 expression and normalizing keratinocyte differentiation.

    Science.gov (United States)

    Dainichi, Teruki; Amano, Satoshi; Matsunaga, Yukiko; Iriyama, Shunsuke; Hirao, Tetsuji; Hariya, Takeshi; Hibino, Toshihiko; Katagiri, Chika; Takahashi, Motoji; Ueda, Setsuko; Furue, Masutaka

    2006-02-01

    Chemical peeling with salicylic acid in polyethylene glycol vehicle (SA-PEG), which specifically acts on the stratum corneum, suppresses the development of skin tumors in UVB-irradiated hairless mice. To elucidate the mechanism through which chemical peeling with SA-PEG suppresses skin tumor development, the effects of chemical peeling on photodamaged keratinocytes and cornified envelopes (CEs) were evaluated in vivo. Among UVB-irradiated hairless mice, the structural atypia and expression of p53 protein in keratinocytes induced by UVB irradiation were intensely suppressed in the SA-PEG-treated mice 28 days after the start of weekly SA-PEG treatments when compared to that in the control UVB-irradiated mice. Incomplete expression of filaggrin and loricrin in keratinocytes from the control mice was also improved in keratinocytes from the SA-PEG-treated mice. In photo-exposed human facial skin, immature CEs were replaced with mature CEs 4 weeks after treatment with SA-PEG. Restoration of photodamaged stratum corneum by treatment with SA-PEG, which may affect remodeling of the structural environment of the keratinocytes, involved the normalization of keratinocyte differentiation and suppression of skin tumor development. These results suggest that the stratum corneum plays a protective role against carcinogenesis, and provide a novel strategy for the prevention of photo-induced skin tumors.

  14. Insulin radioimmunoassay kit (125I) using polyethyleneglycol (PEG) and a double antibody separation method

    International Nuclear Information System (INIS)

    Borza, Virginia; Chariton, Delfina; Neacsu, Elena

    1997-01-01

    Insulin is a polypeptide hormone formed from proinsulin in the b-cells of the islets of Langerhans in the pancreas. It has a widespread effect on carbohydrate, lipid and protein metabolism. Diabetes mellitus is the result of an insulin deficiency brought about either by insufficient insulin secretion or by rapid insulin catabolism. The determination of the insulin level is important for differential etiologic diagnosis and subsequent therapy and prognosis. Insulin radioimmunoassay kit provides a sensitive, precise and specific assay for insulin concentration in serum. Standard and insulin in the patient sample compete with tracer for binding sites on an insulin antibody. The antigen-antibody combination, which forms during incubation time, will be separated from free insulin by different methods. The separation technique using the double antibody technique combined with Polyethyleneglycol (PEG) is presented. The results are compared with the separation method using PEG alone and with double antibody technique. Antiserum to insulin was produced in rats immunized with porcine insulin, while rabbits immunized with rat-g globulin were used as a source for the second antibody.The tested PEG was PEG 6000. The best results were obtained using the double antibody at a 1/50 dilution combined with 7.5 PEG solutions. The time for precipitating the antibody bound fraction by this technique was established to be 30 minutes. The results obtained using this method as separation technique for insulin - antibody complex were better than those obtained using the double antibody techniques or PEG as precipitating agent alone. (authors)

  15. Study of Copolymer Composition on Drug Loading Efficiency of Enalapril in Polymersomes and Cytotoxicity of Drug Loaded Nanoparticles.

    Science.gov (United States)

    Danafar, H; Manjili, H K; Najafi, M

    2016-09-01

    Enalapril was used for hypertension and congestive heart failure. Di-block mPEG-PCL copolymers were synthesized and used to prepare of polymersomes for controlled release of enalapril as a hydrophilic drug. The various methods such as HNMR, FTIR, GPC, DSC, PCS and AFM performed for characterization of the polymersomes. The results of AFM showed that the polymersomes had spherical structure and the size of nanoparticles was 97 nm. Drug-loading efficiency of nanoparticles from copolymers with compositions of mPEG1-PCL1, mPEG2-PCL2, and mPEG3-PCL3 were 14.43%, 19.8%, and 12.33% respectively. The release profile of enalapril for drug loaded nanoparticles prepared from mPEG3-PCL3 was very fast and release profile for the nanoparticles prepared from mPEG1-PCL1 and mPEG2-PCL2 was sustained. The IC 50 value of enalapril was determined to be 8 μM while EPM/m-PEG-PCL nanoparticles did not show significant toxicity at equal concentrations in comparison with enalapril drug. Therapeutic preparations of mPEG-PCL micelle are calibrated by the mouse LD 50 assay. A dose-finding scheme of the polymeric micelle showed a safe dose of mPEG-PCL micelles was approximately 330 mg/kg in mice. The relationship between the numbers of animals, number of doses, duration of the assay used to estimate the LD 50 and the precision of the assay were investigated. Overall, the results was showed that m-PEG-PCL polymersomes can be considered as a promising carrier for hydrophilic drugs. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Preparation of 99mTc-HYNIC-PEG-liposomes for imaging of the focal sites infection

    International Nuclear Information System (INIS)

    Hong, Jun Pyo; Awh, Ok Doo; Kim, Hyun Suk; Lee, Eun Sook; Lee, Tae Sup; Choi, Tae Hyun; Choi, Chang Woon; Lim, Sang Moo

    2002-01-01

    A new linker, hydrazino nicotinamide (HYNIC), was recently introduced for labelling of liposome with 99m Tc. In this study we synthesized HYNIC derivatized PEG (polyethylene glycol)-liposomes radiolabeled with 99m Tc. In order to synthesize HYNIC-DSPE (distearoyl phosphatidyl ethanolamine) which is a crucial component for 99m Tc chelation, first of all succinimidyl 6-BOC-hydrazinopyridine-3-carboxylic acid was synthesized from 6-chloronicotinic acid by three sequential reactions. A DSPE derivative of succinimidyl 6-BOC-hydrazinopyridine-3-carboxylic acid was transformed into HYNIC-DSPE by HCI/dioxane. HYNIC-PEG-liposomes were prepared by hydration of the dried lipid mixture of EPC (egg phosphatidyl choline): PEG-DSPE : HYNIC-DSPE: cholesterol (1.85:0.15:0.07:1, molar ratio). The HYNIC-PEG-liposomes were labeled with 99m Tc in the presence of SnCl 2 ·2H 2 O (a reducing agent) and tricine (a colignad). To investigate the level of in vivo transchelation of 99m Tc in the liposomes, the 99m Tc-HYNIC-PEG-liposomes were incubated with a molar excess of DTPA, cysteine or glutathione solutions at 37 .deg. C for 24 hours. 6-BOC-hydrazinopyridine-3-carboxylic acid was synthesized with 77.3% overall yield. The HYNIC concentration in the PEG-coated liposome dispersion was 1.08 mM. In condition of considering the measured liposome size of 106 nm, the phospholipid concentration of 77.5 μmol/ ml and the liposomal particle number of 5.2x10 14 liposomes/ml, it is corresponded to approximate 1,250 nicotinyl hydrazine group per liposome in HYNIC-PEG-liposome. The removal of free 99m Tc was not necessary because the labeling efficiency were above 99%. The radiolabeled liposomes maintained 98%, 96% and 99%, respectively, of radioactivity after incubation with transchelators. The radiolabeled liposomes possessed above 90% of the radioactivity in serum. These results suggest that the HYNIC can be synthesized easily and applied in labelling of PEG-liposomes with 99m Tc

  17. Microelectrode Arrays and the Use of PEG-Functionalized Diblock Copolymer Coatings

    Directory of Open Access Journals (Sweden)

    Sakshi Uppal

    2014-09-01

    Full Text Available PEG-modified diblock copolymer surfaces have been examined for their compatibility with microelectrode array based analytical methods. The use of PEG-modified polymer surfaces on the arrays was initially problematic because the redox couples used in the experiments were adsorbed by the polymer. This led the current measured by cyclic voltammetry for the redox couple to be unstable and increase with time. However, two key findings allow the experiments to be successful. First, after multiple cyclic voltammograms the current associated with the redox couple does stabilize so that a good baseline current can be established. Second, the rate at which the current stabilizes is consistent every time a particular coated array is used. Hence, multiple analytical experiments can be conducted on an array coated with a PEG-modified diblock copolymer and the data obtained is comparable as long as the data for each experiment is collected at a consistent time point.

  18. Ultrasensitive probing of the protein resistance of PEG surfaces by secondary ion mass spectrometry

    DEFF Research Database (Denmark)

    Kingshott, P.; McArthur, S.; Thissen, H.

    2002-01-01

    The highly sensitive surface analytical techniques X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectrometry (ToF-SIMS) were used to test the resistance of poly(ethylene glycol) (PEG) coatings towards adsorption of lysozyme (LYS) and fibronectin (FN). PEG co...

  19. PEG 3350 (Transipeg) versus lactulose in the treatment of childhood functional constipation: a double blind, randomised, controlled, multicentre trial.

    Science.gov (United States)

    Voskuijl, W; de Lorijn, F; Verwijs, W; Hogeman, P; Heijmans, J; Mäkel, W; Taminiau, J; Benninga, M

    2004-11-01

    Recently, polyethylene glycol (PEG 3350) has been suggested as a good alternative laxative to lactulose as a treatment option in paediatric constipation. However, no large randomised controlled trials exist evaluating the efficacy of either laxative. To compare PEG 3350 (Transipeg: polyethylene glycol with electrolytes) with lactulose in paediatric constipation and evaluate clinical efficacy/side effects. One hundred patients (aged 6 months-15 years) with paediatric constipation were included in an eight week double blinded, randomised, controlled trial. After faecal disimpaction, patients PEG 3350 (2.95 g/sachet) or lactulose (6 g/sachet) while children > or =6 years started with 2 sachets/day. Primary outcome measures were: defecation and encopresis frequency/week and successful treatment after eight weeks. Success was defined as a defecation frequency > or =3/week and encopresis PEG 3350: 3 pre v 7 post treatment/week; lactulose: 3 pre v 6 post/week) and a significant decrease in encopresis frequency (PEG 3350: 10 pre v 3 post/week; lactulose: 8 pre v 3 post/week) was found in both groups (NS). However, success was significantly higher in the PEG group (56%) compared with the lactulose group (29%). PEG 3350 patients reported less abdominal pain, straining, and pain at defecation than children using lactulose. However, bad taste was reported significantly more often in the PEG group. PEG 3350 (0.26 (0.11) g/kg), compared with lactulose (0.66 (0.32) g/kg), provided a higher success rate with fewer side effects. PEG 3350 should be the laxative of first choice in childhood constipation.

  20. Bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles as novel tumor targeting carriers

    International Nuclear Information System (INIS)

    Ding Hong; Yong, Ken-Tye; Roy, Indrajit; Hu Rui; Zhao Lingling; Law, Wing-Cheung; Ji Wei; Liu Liwei; Bergey, Earl J; Prasad, Paras N; Wu Fang; Zhao Weiwei

    2011-01-01

    In this study, we have developed a novel carrier, micelle-type bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles (NPs), for the detection and treatment of pancreatic cancer. These NPs contained 4-arm-PEG as corona, and PLGA as core, the particle surface was conjugated with cyclo(arginine-glycine-aspartate) (cRGD) as ligand for in vivo tumor targeting. The hydrodynamic size of the NPs was determined to be 150-180 nm and the critical micellar concentration (CMC) was estimated to be 10.5 mg l -1 . Our in vitro study shows that these NPs by themselves had negligible cytotoxicity to human pancreatic cancer (Panc-1) and human glioblastoma (U87) cell lines. Near infrared (NIR) microscopy and flow cytometry demonstrated that the cRGD conjugated PLGA-4-arm-PEG polymeric NPs were taken up more efficiently by U87MG glioma cells, over-expressing the α v β 3 integrin, when compared with the non-targeted NPs. Whole body imaging showed that the cRGD conjugated PLGA-4-arm-PEG branched polymeric NPs had the highest accumulation in the pancreatic tumor site of mice at 48 h post-injection. Physical, hematological, and pathological assays indicated low in vivo toxicity of this NP formulation. These studies on the ability of these bioconjugated PLGA-4-arm-PEG polymeric NPs suggest that the prepared polymeric NPs may serve as a promising platform for detection and targeted drug delivery for pancreatic cancer.

  1. Bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles as novel tumor targeting carriers

    Energy Technology Data Exchange (ETDEWEB)

    Ding Hong; Yong, Ken-Tye; Roy, Indrajit; Hu Rui; Zhao Lingling; Law, Wing-Cheung; Ji Wei; Liu Liwei; Bergey, Earl J; Prasad, Paras N [Department of Chemistry, Institute for Lasers, Photonics and Biophotonics, University at Buffalo, State University of New York, Buffalo, NY 14260 (United States); Wu Fang [Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260 (United States); Zhao Weiwei, E-mail: bergeye@buffalo.edu, E-mail: pnprasad@buffalo.edu [Department of Microbiology and Immunology, University at Buffalo, State University of New York, Buffalo, NY 14215 (United States)

    2011-04-22

    In this study, we have developed a novel carrier, micelle-type bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles (NPs), for the detection and treatment of pancreatic cancer. These NPs contained 4-arm-PEG as corona, and PLGA as core, the particle surface was conjugated with cyclo(arginine-glycine-aspartate) (cRGD) as ligand for in vivo tumor targeting. The hydrodynamic size of the NPs was determined to be 150-180 nm and the critical micellar concentration (CMC) was estimated to be 10.5 mg l{sup -1}. Our in vitro study shows that these NPs by themselves had negligible cytotoxicity to human pancreatic cancer (Panc-1) and human glioblastoma (U87) cell lines. Near infrared (NIR) microscopy and flow cytometry demonstrated that the cRGD conjugated PLGA-4-arm-PEG polymeric NPs were taken up more efficiently by U87MG glioma cells, over-expressing the {alpha}{sub v{beta}3} integrin, when compared with the non-targeted NPs. Whole body imaging showed that the cRGD conjugated PLGA-4-arm-PEG branched polymeric NPs had the highest accumulation in the pancreatic tumor site of mice at 48 h post-injection. Physical, hematological, and pathological assays indicated low in vivo toxicity of this NP formulation. These studies on the ability of these bioconjugated PLGA-4-arm-PEG polymeric NPs suggest that the prepared polymeric NPs may serve as a promising platform for detection and targeted drug delivery for pancreatic cancer.

  2. Fluorescent water-Soluble Probes Based on Ammonium Cation Peg Substituted Perylenepisimides: Synthesis, Photophysical Properties, and Live Cell Images

    Science.gov (United States)

    Yang, Wei; Cai, Jiaxuan; Zhang, Shuchen; Yi, Xuegang; Gao, Baoxiang

    2018-01-01

    To synthesize perylenbisimides (PBI) fluorescent probes that will improve the water-soluble ability and the cytocompatibility, the synthesis and properties of fluorescent water-soluble probes based on dendritic ammonium cation polyethylene glycol (PEG) substituted perylenebisimides(GPDIs) are presented. As we expected, with increased ammonium cation PEG, the aggregation of the PBI in an aqueous solution is completely suppressed by the hydrophilic ammonium cation PEG groups. And the fluorescence quantum yield increases from 25% for GPDI-1 to 62% for GPDI-2. When incubated with Hela cells for 48 h, the viabilities are 71% (for GPDI-1) and 76% (for GPDI-2). Live cell imaging shows that these probes are efficiently internalized by HeLa cells. The study of the photophysical properties indicated increasing the ammonium cation PEG generation can increase the fluorescence quantum yield. Live cell imaging shows that with the ammonium cation PEG chains of perylenebisimides has high biocompatibility. The exceptionally low cytotoxicity is ascribed to the ammonium cation PEG chains, which protect the dyes from nonspecifically interacting with the extracellular proteins. Live cell imaging shows that ammonium cations PEG chains can promote the internalization of these probes.

  3. Construction and characterization of Gal-chitosan graft methoxy poly (ethylene glycol) (Gal-CS-mPEG) nanoparticles as efficient gene carrier

    Science.gov (United States)

    Jin, Jiting; Fu, Wandong; Liao, Miaofei; Han, Baoqin; Chang, Jing; Yang, Yan

    2017-10-01

    In the present study, galactosylated chitosan (Gal-CS) was conjugated with methoxy poly(ethylene glycol) (mPEG) as a hydrophilic group. The structure of Gal-CS-mPEG polymer was characterized and the nanoparticles (NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-mPEG NPs. The morphology of Gal-CS-mPEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-mPEG NPs and pDNA, and the protection of pDNA against DNase I and serum degradation by Gal-CS-mPEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-mPEG NPs had strong interaction with pDNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect pDNA from DNase I and serum degradation. Gal-CS-mPEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-mPEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-mPEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-mPEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.

  4. Feasibility and Safety of Overtubes for PEG-Tube Placement in Patients with Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Crispin O. Musumba

    2015-01-01

    Full Text Available Background. Percutaneous endoscopic gastrostomy (PEG placement using the “pull” technique is commonly utilized for providing nutritional support in head and neck cancer (HNC patients, but it may be complicated by peristomal metastasis in up to 3% of patients. Overtube-assisted PEG placement might reduce this risk. However, this technique has not been systemically studied for this purpose to date. Methods. Retrospective analysis of consecutive patients with HNC who underwent overtube-assisted PEG placement at Westmead Hospital, Australia, between June 2011 and December 2013. Data were extracted from patients’ endoscopy reports and case notes. We present our technique for PEG insertion and discuss the feasibility and safety of this method. Results. In all 53 patients studied, the PEG tubes were successfully placed using 25 cm long flexible overtubes, in 89% prophylactically (before commencing curative chemoradiotherapy, and in 11% reactively (for treatment of tumor related dysphagia or weight loss. During a median follow-up period of 16 months, 3 (5.7% patients developed peristomal infection and 3 others developed self-limiting peristomal pain. There were no cases of overtube-related adverse events or overt cutaneous metastases observed. Conclusions. Overtube-assisted PEG placement in patients with HNC is a feasible, simple, and safe technique and might be effective for preventing cutaneous metastasis.

  5. Improving aqueous solubility and antitumor effects by nanosized gambogic acid-mPEG2000 micelles

    Directory of Open Access Journals (Sweden)

    Cai LL

    2013-12-01

    Full Text Available Lulu Cai,1,* Neng Qiu,2,* Mingli Xiang,3,* Rongsheng Tong,1 Junfeng Yan,1 Lin He,1 Jianyou Shi,1 Tao Chen,4 Jiaolin Wen,3 Wenwen Wang,3 Lijuan Chen31Department of Pharmacy, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, 2College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, 3State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China; 4Faculty of Pharmacy, University of Montreal, Montreal, QC, Canada *These authors contributed equally to this paperAbstract: The clinical application of gambogic acid, a natural component with promising antitumor activity, is limited due to its extremely poor aqueous solubility, short half-life in blood, and severe systemic toxicity. To solve these problems, an amphiphilic polymer-drug conjugate was prepared by attachment of low molecular weight (ie, 2 kDa methoxy poly(ethylene glycol methyl ether (mPEG to gambogic acid (GA-mPEG2000 through an ester linkage and characterized by 1H nuclear magnetic resonance. The GA-mPEG2000 conjugates self-assembled to form nanosized micelles, with mean diameters of less than 50 nm, and a very narrow particle size distribution. The properties of the GA-mPEG2000 micelles, including morphology, stability, molecular modeling, and drug release profile, were evaluated. MTT (3-(4,5-dimethylthiazol-2-yl-2,5 diphenyl tetrazolium bromide tests demonstrated that the GA-mPEG2000 micelle formulation had obvious cytotoxicity to tumor cells and human umbilical vein endothelial cells. Further, GA-mPEG2000 micelles were effective in inhibiting tumor growth and prolonged survival in subcutaneous B16-F10 and C26 tumor models. Our findings suggest that GA-mPEG2000 micelles may have promising applications in tumor therapy.Keywords: gambogic acid, poly(ethylene glycol-drug conjugate, micelle, antitumor, toxicity

  6. Dose response of PEG 3350 for the treatment of childhood fecal impaction.

    Science.gov (United States)

    Youssef, Nader N; Peters, John M; Henderson, Wendy; Shultz-Peters, Sandra; Lockhart, Danielle K; Di Lorenzo, Carlo

    2002-09-01

    To investigate the efficacy and safety of polyethylene glycol (PEG) 3350 in the treatment of childhood fecal impaction. This was a prospective, double-blind, parallel, randomized study of 4 doses of PEG 3350; 0.25 g/kg per day, 0.5 g/kg per day, 1 g/kg per day, 1.5 g/kg per day, given for 3 days in children with constipation for >3 months and evidence of fecal impaction. Forty patients completed the study (27 boys, median age 7.5, range 3.3-13.1 years). Disimpaction occurred in 75% of children, with a significant difference between the two higher doses and the lower doses (95% vs 55%, P PEG 3350 is safe and effective in the treatment of childhood fecal impaction at doses of 1 and 1.5 g/kg per day.

  7. Preparation and mechanical properties of PLA-PEG copolymers modified by radiation-induced crosslinking of low energy electron beams

    International Nuclear Information System (INIS)

    Peikai Miao; Wenrui Tang; Ke Zeng; Yan Tang; Yipeng Wang; Hongfei Zhou; Ke Zhou; Tao Liu; Gang Yang

    2007-01-01

    PLA-PEG copolymer is wildly applied in medical and pharmaceutical fields, but its mechanical properties are not so good, such as the tensile intensity and elongation at break. To improve these properties, PLA-PEG copolymers were synthesized and irradiated using low energy electron beams (EB) with various irradiation doses in the presence of 3 wt% polyfunctional monomer (triallylcyanurate, TAC) as crosslinking agent to introduce crosslinking between polymer chains. It was found that with the increase of the irradiation doses, the tensile intensity of the PLA-PEG increased, while the elongation at break decreased, the most optimal irradiation dose was 80 kGy, the tensile intensity was 12.5 MPa and 19.9 MPa, corresponding to the elongation at break of 282.8 % and 28.7% for PLA9-PEG6 and PLA11-PEG6, respectively. Meanwhile, the solvent resistance of crosslinked sample was improved obviously at this dose. The crosslinked PLA-PEG copolymer can be applied to packaging materials, tubes and so on. (Author)

  8. {sup 18}F-PEG-biotin: Precursor (boroaryl-PEG-biotin) synthesis, {sup 18}F-labelling and an in-vitro assessment of its binding with Neutravidin{sup TM}-trastuzumab pre-treated cells

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tim A.D., E-mail: t.smith@abdn.ac.uk [Biomedical Physics Building, John Mallard PET Unit, Aberdeen Biomedical Imaging Centre, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD (United Kingdom); Simpson, Michael; Cheyne, Richard [Biomedical Physics Building, John Mallard PET Unit, Aberdeen Biomedical Imaging Centre, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD (United Kingdom); School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Trembleau, Laurent [School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom)

    2011-10-15

    In terms of nuclear decay {sup 18}F is the most ideal PET nuclide but its short t{sub 1/2} precludes its use for directly labelling whole antibodies due to their long blood residence times. Pre-targeted imaging using affinity systems such as Neutravidin{sup TM}-biotin facilitates the application of short-lived nuclides by their attachment to biotin for imaging cell surface proteins targeted with Neutravidin{sup TM}-conjugated antibodies. Methods: Boroaryl functionalised biotin was prepared with a PEG linker and radiolabelled by incubation with {sup 18}F in acidified aqueous solution. Cells expressing high (SKBr3), medium (MDA-MB-453) and low (MDA-MB-468) levels of HER-2 were pre-incubated with Neutravidin{sup TM}-conjugated trastuzumab, washed, and then incubated with {sup 18}F-PEG-biotin. Results: The {sup 18}F-fluorination of boroaryl-PEG-biotin was much more efficient than reported for other versions of boroaryl-biotin. The novel {sup 18}F-PEG-biotin was demonstrated to bind to HER-2-expressing cells in-vitro pre-incubated with Neutravidin{sup TM}-conjugated trastuzumab. Conclusion: Biotin can be functionalised with boroaryl and readily {sup 18}F-radiolabelled in aqueous solution and will bind to cells pre-incubated with Neutravidin{sup TM}-antibody conjugates. - Highlights: > Boroaryl-biotin precursor is prepared. > Rapid {sup 18}F-fluorination is demonstrated. > HER-2 expressing breast cancer cells pre-treated with trastuzumab-Neutravidin{sup TM}. > {sup 18}F-PEG-biotin binding to pre-treated cells corresponds with HER-2 expression.

  9. Quantitative analysis of polyethylene glycol (PEG) and PEGylated proteins in animal tissues by LC-MS/MS coupled with in-source CID.

    Science.gov (United States)

    Gong, Jiachang; Gu, Xiaomei; Achanzar, William E; Chadwick, Kristina D; Gan, Jinping; Brock, Barry J; Kishnani, Narendra S; Humphreys, W Griff; Iyer, Ramaswamy A

    2014-08-05

    The covalent conjugation of polyethylene glycol (PEG, typical MW > 10k) to therapeutic peptides and proteins is a well-established approach to improve their pharmacokinetic properties and diminish the potential for immunogenicity. Even though PEG is generally considered biologically inert and safe in animals and humans, the slow clearance of large PEGs raises concerns about potential adverse effects resulting from PEG accumulation in tissues following chronic administration, particularly in the central nervous system. The key information relevant to the issue is the disposition and fate of the PEG moiety after repeated dosing with PEGylated proteins. Here, we report a novel quantitative method utilizing LC-MS/MS coupled with in-source CID that is highly selective and sensitive to PEG-related materials. Both (40K)PEG and a tool PEGylated protein (ATI-1072) underwent dissociation in the ionization source of mass spectrometer to generate a series of PEG-specific ions, which were subjected to further dissociation through conventional CID. To demonstrate the potential application of the method to assess PEG biodistribution following PEGylated protein administration, a single dose study of ATI-1072 was conducted in rats. Plasma and various tissues were collected, and the concentrations of both (40K)PEG and ATI-1072 were determined using the LC-MS/MS method. The presence of (40k)PEG in plasma and tissue homogenates suggests the degradation of PEGylated proteins after dose administration to rats, given that free PEG was absent in the dosing solution. The method enables further studies for a thorough characterization of disposition and fate of PEGylated proteins.

  10. Relationship between complement activation, cellular uptake and surface physicochemical aspects of novel PEG-modified nanocapsules.

    Science.gov (United States)

    Mosqueira, V C; Legrand, P; Gulik, A; Bourdon, O; Gref, R; Labarre, D; Barratt, G

    2001-11-01

    The aim of our work was to examine the relationship between modifications of the surface of nanocapsules (NC) by adsorption or covalent grafting of poly(ethylene oxide) (PEG), and changes in their phospholipid (PL) content on complement activation (C3 cleavage) and on uptake by macrophages. The physicochemical characterization of the NC included an investigation of their properties, such as surface charge, size, hydrophilicity, morphology and homogeneity. This is the first time that such properties have been correlated with biological interactions for NC, a novel carrier system with a structure more complex than nanospheres. C3 crossed immunoelectrophoresis revealed the reduced activation for NC with longer PEG chain and higher density, although all formulations induced C3 cleavage to a lesser or greater extent. NC bearing PEG covalently bound to the surface were weaker activators of complement than plain PLA [poly(D,L-lactide)] NC or nanospheres (NS). Furthermore, the fluorescent/confocal microscopy of J774A1 cells in contact with NC reveal a dramatically reduced interaction with PEG-bearing NC. However, the way in which PEG was attached (covalent or adsorbed) seemed to affect the mechanism of uptake. Taken together, these results suggest that the low level of protein binding to NC covered with a high density of 20kDa PEG chains is likely to be due to the steric barriers surrounding these particles, which prevents protein adsorption and reduces their interaction with macrophages.

  11. Nursing Issues in Patients with PEG

    OpenAIRE

    Konířová, Lenka

    2013-01-01

    Bachelor thesis were written on theoretic-empirical bases. The theoretical part is dedicated to general introduction into anatomy and physiology of stomach. The following chapter is about nutrition, the explanation of the terms malnutrioton, nutritional support, enteral nutrition as well as its indications, contraindications, complications, types and forms of artificial nutrition included. The core chapter is about the implementation and treatement of PEG, the psychosocial aspects and specifi...

  12. Randomized clinical trial: macrogol/PEG 3350 plus electrolytes for treatment of patients with constipation associated with irritable bowel syndrome.

    Science.gov (United States)

    Chapman, R W; Stanghellini, V; Geraint, M; Halphen, M

    2013-09-01

    Polyethylene glycol (PEG) 3350 plus electrolytes (PEG 3350+E) is an established treatment for constipation and has been proposed as a treatment option for constipation associated with irritable bowel syndrome (IBS-C). This study aimed to compare the efficacy and safety of PEG 3350+E vs. placebo in adult patients with IBS-C. Following a 14-day run-in period without study medication, patients with confirmed IBS-C were randomized to receive PEG 3350+E (N=68) or placebo (N=71) for 28 days. The primary endpoint was the mean number of spontaneous bowel movements (SBMs) per day in the last treatment week. In both groups, mean weekly number of SBMs (±s.d.) increased from run-in. The difference between the groups in week 4 (PEG 3350+E, 4.40±2.581; placebo, 3.11±1.937) was statistically significant (95% confidence interval: 1.17, 1.95; PPEG 3350+E, there was no difference vs. placebo. Spontaneous complete bowel movements, responder rates, stool consistency, and severity of straining also showed superior improvement in the PEG 3350+E group over placebo in week 4. The most common drug related treatment-emergent adverse events were abdominal pain (PEG 3350+E, 4.5%; placebo, 0%) and diarrhoea (PEG 3350+E, 4.5%; placebo, 4.3%). In IBS-C, PEG 3350+E was superior to placebo for relief of constipation, and although a statistically significant improvement in abdominal discomfort/pain was observed compared with baseline, there was no associated improvement compared with placebo. PEG 3350+E is a well-established and effective treatment that should be considered suitable for use in IBS-C.

  13. Facile Photoimmobilization of Proteins onto Low-Binding PEG-Coated Polymer Surfaces

    DEFF Research Database (Denmark)

    Larsen, Esben Kjær Unmack; Mikkelsen, Morten Bo Lindholm; Larsen, Niels Bent

    2014-01-01

    was verified for both enzymes and antibodies, and their presence on the surface was confirmed by X-ray photoelectron spectroscopy (XPS) and confocal fluorescence microscopy. Conjugation of capture antibody onto the PEG coating was employed for a simplified ELISA protocol without the need for blocking uncoated...... surface areas, showing ng/mL sensitivity to a cytokine antigen target. Moreover, spatially patterned attachment of fluorescently labeled protein onto the low-binding PEG-coated surface was achieved with a projection lithography system that enabled the creation of micrometer-sized protein features....

  14. Preparation and Property Evaluation of Conductive Hydrogel Using Poly (Vinyl Alcohol/Polyethylene Glycol/Graphene Oxide for Human Electrocardiogram Acquisition

    Directory of Open Access Journals (Sweden)

    Xueliang Xiao

    2017-06-01

    Full Text Available Conductive hydrogel combined with Ag/AgCl electrode is widely used in the acquisition of bio-signals. However, the high adhesiveness of current commercial hydrogel causes human skin allergies and pruritus easily after wearing hydrogel for electrodes for a long time. In this paper, a novel conductive hydrogel with good mechanical and conductive performance was prepared using polyvinyl alcohol (PVA, polyethylene glycol (PEG, and graphene oxide (GO nanoparticles. A cyclic freezing–thawing method was employed under processing conditions of −40 °C (8 h and 20 °C (4 h separately for three cycles in sequence until a strong conductive hydrogel, namely, PVA/PEG/GO gel, was obtained. Characterization (Fourier transform infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy results indicated that the assembled hydrogel was successfully prepared with a three-dimensional network structure and, thereafter, the high strength and elasticity due to the complete polymeric net formed by dense hydrogen bonds in the freezing process. The as-made PVA/PEG/GO hydrogel was then composited with nonwoven fabric for electrocardiogram (ECG electrodes. The ECG acquisition data indicated that the prepared hydrogel has good electro-conductivity and can obtain stable ECG signals for humans in a static state and in motion (with a small amount of drift. A comparison of results indicated that the prepared PVA/PEG/GO gel obtained the same quality of ECG signals with commercial conductive gel with fewer cases of allergies and pruritus in volunteer after six hours of wear.

  15. Evaluation of self-assembled HCPT-loaded PEG-b-PLA nanoparticles by comparing with HCPT-loaded PLA nanoparticles.

    Science.gov (United States)

    Yang, Xiangrui; Wu, Shichao; Wang, Yange; Li, Yang; Chang, Di; Luo, Yin; Ye, Shefang; Hou, Zhenqing

    2014-12-01

    We present a dialysis technique to prepare the 10-hydroxycamptothecin (HCPT)-loaded nanoparticles (NPs) using methoxypolyethylene glycol-poly(D,L-lactide) (PEG-b-PLA) and PLA, respectively. Both HCPT-loaded PEG-b-PLA NPs and HCPT-loaded PLA NPs were characterized by differential scanning calorimetry (DSC), dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that the HCPT-loaded PEG-b-PLA NPs and HCPT-loaded PLA NPs presented a hydrodynamic particle size of 120.1 and 226.8 nm, with a polydispersity index of 0.057 and 0.207, a zeta potential of -31.2 and -45.7 mV, drug encapsulation efficiency of 44.52% and 44.94%, and drug-loaded content of 7.42% and 7.49%, respectively. The HCPT-loaded PEG-b-PLA NPs presented faster drug release rate compared to the HCPT-loaded PLA NPs. The HCPT-loaded PEG-b-PLA NPs presented higher cytotoxicity than the HCPT-loaded PLA NPs. These results suggested that the HCPT-loaded PEG-b-PLA NPs presented better characteristics for drug delivery compared to HCPT-loaded PLA NPs.

  16. Evaluation of a novel GRPR antagonist for prostate cancer PET imaging: [64Cu]-DOTHA2-PEG-RM26.

    Science.gov (United States)

    Mansour, Nematallah; Paquette, Michel; Ait-Mohand, Samia; Dumulon-Perreault, Véronique; Guérin, Brigitte

    2018-01-01

    Gastrin releasing peptide receptors (GRPRs) are significantly over-expressed on a large proportion of prostate cancers making them prime candidates for receptor-mediated nuclear imaging by PET. Recently, we synthesized a novel bifunctional chelator (BFC) bearing hydroxamic acid arms (DOTHA 2 ). Here we investigated the potential of a novel DOTHA 2 -conjugated, 64 Cu-radiolabeled GRPR peptide antagonist, [D-Phe 6 -Sta 13 -Leu 14 -NH 2 ]bombesin(6-14) (DOTHA 2 -PEG-RM26) to visualize prostate tumors by PET imaging. DOTHA 2 -PEG-RM26 was conveniently and efficiently assembled on solid support. The compound was radiolabeled with 64 Cu and its affinity, stability, cellular uptake on PC3 prostate cancer cells were evaluated. The in vitro and in vivo behavior of [ 64 Cu]DOTHA 2 -PEG-RM26 was examined by PET imaging using human PC3 prostate cancer xenografts and its behavior was compared to that of the analogous [ 64 Cu]NOTA-PEG-RM26. The inhibition constant of nat Cu-DOTHA 2 -PEG-RM26 was in the low nanomolar range (0.68±0.19 nM). The [ 64 Cu]DOTHA 2 -PEG-RM26 conjugate was prepared with a labeling yield >95% and molar activity of 56±3 GBq/μmol after a 5-min room temperature labeling. [ 64 Cu]-DOTHA 2 -PEG-RM26 demonstrated rapid blood and renal clearance as well as a high tumor uptake. Small animal PET images confirmed high and specific uptake in PC3 tumor. Both [ 64 Cu]-DOTHA 2 -PEG-RM26 and [ 64 Cu]-NOTA-PEG-RM26 displayed similar tumor and normal tissue uptakes at early time point post injection. [ 64 Cu]-DOTHA 2 -PEG-RM26 allows visualization of prostate tumors by PET imaging. DOTHA 2 enables fast 64 Cu chelation under mild condition, and as such could be used advantageously for the development of other 64 Cu-labeled peptide-derived PET tracers. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Redox and pH dual-responsive PEG and chitosan-conjugated hollow mesoporous silica for controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Jian; Li, Xian; Zhang, Sha; Liu, Jie; Di, Donghua [Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning Province 110016 (China); Zhang, Ying [School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, PR China. (China); Zhao, Qinfu, E-mail: zqf021110505@163.com [Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning Province 110016 (China); Wang, Siling, E-mail: silingwang@syphu.edu.cn [Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, Liaoning Province 110016 (China)

    2016-10-01

    In this paper, a hollow mesoporous silica nanoparticles (HMSN) was used as the drug vehicle to develop the redox and pH dual stimuli-responsive delivery system, in which the chitosan (CS), a biodegradable cationic polymer, was grafted on the surface of HMSN via the cleavable disulfide bonds. CS was chosen as the gatekeeper mainly due to its appropriate molecular weight as well as possessing abundant amino groups which could be protonated in the acidic condition to achieve pH-responsive drug release. In addition, the PEG was further grafted on the surface of CS to increase the stability and biocompatibility under physiological conditions. The DOX loaded DOX/HMSN-SS-CS@PEG had a relatively high drug loading efficiency up to 32.8%. In vitro release results indicated that DOX was dramatically blocked within the mesopores of HMSN-SS-CS@PEG in pH 7.4 PBS without addition of GSH. However, the release rate of DOX was markedly increased after the addition of 10 mM GSH or in pH 5.0 release medium. Moreover, the release of DOX was further improved in pH 5.0 PBS with 10 mM GSH. The HMSN-SS-CS@PEG could markedly decrease the hemolysis percent and protein adsorption, and increase the biocompatibility and stability of HMSN compared with the HMSN-SS-CS and bare HMSN. This work suggested an exploration about HMSN based stimuli-responsive drug delivery and these results demonstrated that HMSN-SS-CS@PEG exhibited dual-responsive drug release property and could be used as a promising carrier for cancer therapy. - Highlights: • Hollow mesoporous silica nanoparticles (HMSN) were used as a drug carrier. • Chitosan (CS) and PEG were grafted on the surface of HMSN via disulfide bonds. • The DOX loaded DOX/HMSN-SS-CS@PEG had a high drug loading efficiency up to 32.8%. • DOX/HMSN-SS-CS@PEG showed redox/pH dual-responsive drug release property in vitro. • The grafted PEG could increase the biocompatibility and stability of HMSN.

  18. Redox and pH dual-responsive PEG and chitosan-conjugated hollow mesoporous silica for controlled drug release

    International Nuclear Information System (INIS)

    Jiao, Jian; Li, Xian; Zhang, Sha; Liu, Jie; Di, Donghua; Zhang, Ying; Zhao, Qinfu; Wang, Siling

    2016-01-01

    In this paper, a hollow mesoporous silica nanoparticles (HMSN) was used as the drug vehicle to develop the redox and pH dual stimuli-responsive delivery system, in which the chitosan (CS), a biodegradable cationic polymer, was grafted on the surface of HMSN via the cleavable disulfide bonds. CS was chosen as the gatekeeper mainly due to its appropriate molecular weight as well as possessing abundant amino groups which could be protonated in the acidic condition to achieve pH-responsive drug release. In addition, the PEG was further grafted on the surface of CS to increase the stability and biocompatibility under physiological conditions. The DOX loaded DOX/HMSN-SS-CS@PEG had a relatively high drug loading efficiency up to 32.8%. In vitro release results indicated that DOX was dramatically blocked within the mesopores of HMSN-SS-CS@PEG in pH 7.4 PBS without addition of GSH. However, the release rate of DOX was markedly increased after the addition of 10 mM GSH or in pH 5.0 release medium. Moreover, the release of DOX was further improved in pH 5.0 PBS with 10 mM GSH. The HMSN-SS-CS@PEG could markedly decrease the hemolysis percent and protein adsorption, and increase the biocompatibility and stability of HMSN compared with the HMSN-SS-CS and bare HMSN. This work suggested an exploration about HMSN based stimuli-responsive drug delivery and these results demonstrated that HMSN-SS-CS@PEG exhibited dual-responsive drug release property and could be used as a promising carrier for cancer therapy. - Highlights: • Hollow mesoporous silica nanoparticles (HMSN) were used as a drug carrier. • Chitosan (CS) and PEG were grafted on the surface of HMSN via disulfide bonds. • The DOX loaded DOX/HMSN-SS-CS@PEG had a high drug loading efficiency up to 32.8%. • DOX/HMSN-SS-CS@PEG showed redox/pH dual-responsive drug release property in vitro. • The grafted PEG could increase the biocompatibility and stability of HMSN.

  19. Enhancement of dielectric permittivity by incorporating PDMS-PEG multiblock copolymers in silicone elastomers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    2015-01-01

    A silicone elastomer from PDMS-PEG multiblock copolymer has been prepared by use of silylation reactions for both copolymer preparation and crosslinking. The dielectric and mechanical properties of the silicone elastomers were carefully investigated, as well as the morphology of the elastomers wa...... to a significantly increased dielectric permittivity. The conductivity also remained low due to the resulting discontinuity in PEG within the silicone matrix....

  20. Facile synthesis of mPEG-luteolin-capped silver nanoparticles with antimicrobial activity and cytotoxicity to neuroblastoma SK-N-SH cells.

    Science.gov (United States)

    Qing, Weixia; Wang, Yong; Li, Xiao; Lu, Minghua; Liu, Xiuhua

    2017-12-01

    We firstly report a facile route for the green synthesis of mPEG-luteolin-capped silver nanoparticles (mPEG-luteolin-AgNPs) using mPEG-luteolin as both the reducer and stabilizer. The reaction was carried out in a stirred aqueous solution at 50°C without additional poisonous reagents. The prepared mPEG-luteolin-AgNPs was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), zeta potential and UV-vis (UV-vis) spectrum, respectively. The proportions of mPEG-luteolin capped silver nanoparticles is about 89.9%, and the content of silver is 6.65%. The mPEG-luteolin-AgNPs was evaluated the antimicrobial effects on Staphlococcus aureus, Extended spectrum β-Lactamases Staphlococcus aureus, Escherichia Coli and Extended spectrum β-Lactamases Escherichia Coli using drilling hole method. The results showed that both gram-positive and gram-negative bacteria were killed by the mPEG-luteolin-AgNPs at low concentration. Meanwhile, the cell viability assay demonstrated that mPEG-luteolin-AgNPs had toxic effects on human neuroblastoma SK-N-SH cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Effect of different plasticizers on poly(N-vinyl-2-pyrrolidone) hydrogels cross-linked by radiation

    International Nuclear Information System (INIS)

    Alcantara, Mara Tania S.; Giannini, Danielle R.; Brant, Antonio J.C.; Riella, Humberto G.; Lugao, Ademar B.

    2011-01-01

    The use of hydrogel membranes usually demands polymers capable of forming films with high elastic and flexible properties besides having high water absorption. In terms of improvements of polymer plasticity, addition of special plasticizers to polymers can do it with promising results, although within limits of concentrations. The objective of this study was to evaluate the different effects of poly(enthylene glycol) (PEG) and glycerol as plasticizers on hydrogel membranes synthesized from poly(N-vinyl-2-pyrrolidone) (PVP) as the main polymer in aqueous polymeric solutions. For that, hydrogels of PVP/agar/PEG, PVP/agar/glycerol and without agar or plasticizer were simultaneously synthesized and sterilized by irradiation of mixtures of such products in aqueous solutions, using gamma-rays from 60 Co source at a dose of 25 kGy. The results based on gel fraction, swelling in water, and some mechanical tests suggest that the degree of PVP cross-linking prevailed over the greater hydrophilicity of glycerol compared to that of PEG with regard to the degree of swelling of the hydrogels. (author)

  2. Enhanced mechanical properties of linear segmented shape memory poly(urethane-urea) by incorporating flexible PEG400 and rigid piperazine

    Science.gov (United States)

    Zhang, Xiao-Yan; Ma, Yu-Fei; Li, Yong-Gang; Wang, Pin-Pin; Wang, Yuan-Liang; Luo, Yan-Feng

    2012-12-01

    The goal of this study is to design and synthesize a linear segmented shape memory poly(urethane-urea) (SMPUU) that possesses near-body-temperature shape memory temperature ( T tran) and enhanced mechanical properties by incorporating flexible poly(ethylene glycol) 400 (PEG400) to form poly(D,L-lactic acid)-based macrodiols (PDLLA-PEG400-PDLLA) and then rigid piperazine (PPZ) as a chain extender to form the desired SMPUUs (PEG400-PUU-PPZ). PEG400 increased M n while maintaining a lower T g of PDLLA-PEG400-PDLLA, which together with PPZ improved the mechanical properties of PEG400-PUU-PPZ. The obtained optimum SMPUU with enhanced mechanical properties ( σ y = 24.28 MPa; ɛ f = 698%; U f = 181.5 MJ/m3) and a T g of 40.62°C exhibited sound shape memory properties as well, suggesting a promising SMPUU for in vivo biomedical applications.

  3. A soft and conductive PDMS-PEG block copolymer as a compliant electrode for dielectric elastomers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    Conductive PDMS-PEG block copolymers (Mn = 3 – 5 kg/mol) were chain-extended (Mn = 30 – 45 kg/mol) using hydrosilylation reaction as presented in figure 1. Subsequently, the extended copolymers were added to a conductive nano-filler (multi-walled carbon nanotubes – MWCNTs) in order to enhance...... conductivity. The combination of soft chainextended PDMS-PEG block copolymers and conductive MWCNTs results in a soft and conductive block copolymer composite which potentially can be used as a compliant and highly stretchable electrode for dielectric elastomers. The addition of MWCNTs into the PDMS-PEG matrix...... MWCNTs is 10-3 S/cm compared to 10-1 S/cm of a non-stretchable reference conducting silicone elastomer (LR3162 from Wacker). Furthermore, PDMS-PEG block copolymer with 4 phr MWCNTs (Young’s modulus, Y = 0.26 MPa) is softer and more stretchable thanLR3162 (Y = 1.17 MPa)....

  4. Bioprinting 3D cell-laden hydrogel microarray for screening human periodontal ligament stem cell response to extracellular matrix

    International Nuclear Information System (INIS)

    Ma, Yufei; Ji, Yuan; Huang, Guoyou; Zhang, Xiaohui; Xu, Feng; Ling, Kai

    2015-01-01

    Periodontitis is an inflammatory disease negatively affecting up to 15% of adults worldwide. Periodontal ligament stem cells (PDLSCs) hold great promises for periodontal tissue regeneration, where it is necessary to find proper extracellular matrix (ECM) materials (e.g., composition, concentration). In this study, we proposed a bioprinting-based approach to generate nano-liter sized three-dimensional (3D) cell-laden hydrogel array with gradient of ECM components, through controlling the volume ratio of two hydrogels, such as gelatin methacrylate (GelMA) and poly(ethylene glycol) (PEG) dimethacrylate. The resulting cell-laden array with a gradient of GelMA/PEG composition was used to screen human PDLSC response to ECM. The behavior (e.g., cell viability, spreading) of human PDLSCs in GelMA/PEG array were found to be depended on the volume ratios of GelMA/PEG, with cell viability and spreading area decreased along with increasing the ratio of PEG. The developed approach would be useful for screening cell-biomaterial interaction in 3D and promoting regeneration of functional tissue. (paper)

  5. PEG-Immobilized Keratin for Protein Drug Sequestration and pH-Mediated Delivery

    Directory of Open Access Journals (Sweden)

    Roche C. de Guzman

    2016-01-01

    Full Text Available Protein drugs like growth factors are promising therapeutics for damaged-tissue repair. Their local delivery often requires biomaterial carriers for achieving the therapeutic dose range while extending efficacy. In this study, polyethylene glycol (PEG and keratin were crosslinked and used as sponge-like scaffolds (KTN-PEG to absorb test proteins with different isoelectric points (pI: albumin (~5, hemoglobin (~7, and lysozyme (~11. The protein release kinetics was influenced by charge at physiological pH 7.4. The keratin network, with pI 5.3, electrostatically attracted lysozyme and repulsed albumin generating the release rate profile: albumin > hemoglobin > lysozyme. However, under acidic conditions (pH 4, all proteins including keratins were positively charged and consequently intermolecular repulsion altered the release hierarchy, now determined by size (MW diffusion: lysozyme (14 kDa > hemoglobin (64 kDa > albumin (66 kDa. Vascular endothelial growth factor C (VEGF-C, with properties comparable to lysozyme, was absorbed into the KTN-PEG scaffold. Endothelial cells cultured on this substrate had significantly larger numbers than on scaffolds without VEGF-C suggesting that the ionically bound and retained growth factor at neutral pH indirectly increased acute cell attachment and viability. PEG and keratin based sequestrations of proteins with basic pIs are therefore a feasible strategy with potential applications for selective biologics delivery.

  6. Aqueous biphasic systems containing PEG-based deep eutectic solvents for high-performance partitioning of RNA.

    Science.gov (United States)

    Zhang, Hongmei; Wang, Yuzhi; Zhou, Yigang; Xu, Kaijia; Li, Na; Wen, Qian; Yang, Qin

    2017-08-01

    In this work, 16 kinds of novel deep eutectic solvents (DESs) composed of polyethylene glycol (PEG) and quaternary ammonium salts, were coupled with Aqueous Biphasic Systems (ABSs) to extract RNA. The phase forming ability of ABSs were comprehensively evaluated, involving the effects of various proportions of DESs' components, carbon chain length and anions species of quaternary ammonium salts, average molecular weights of PEG and inorganic salts nature. Then the systems were applied in RNA extraction, and the results revealed that the extraction efficiency values were distinctly enhanced by relatively lower PEG content in DESs, smaller PEG molecular weights, longer carbon chain of quaternary ammonium salts and more hydrophobic inorganic salts. Then the systems composed of [TBAB][PEG600] and Na 2 SO 4 were utilized in the influence factor experiments, proving that the electrostatic interaction was the dominant force for RNA extraction. Therefore, back-extraction efficiency values ranging between 85.19% and 90.78% were obtained by adjusting the ionic strength. Besides, the selective separation of RNA and tryptophane (Trp) was successfully accomplished. It was found that 86.19% RNA was distributed in the bottom phase, while 72.02% Trp was enriched in the top phase in the novel ABSs. Finally, dynamic light scattering (DLS) and transmission electron microscope (TEM) were used to further investigate the extraction mechanism. The proposed method reveals the outstanding feasibility of the newly developed ABSs formed by PEG-based DESs and inorganic salts for the green extraction of RNA. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Thermo-responsive hydrogels for intravitreal injection and biomolecule release

    Science.gov (United States)

    Drapala, Pawel

    In this dissertation, we develop an injectable polymer system to enable localized and prolonged release of therapeutic biomolecules for improved treatment of Age-Related Macular Degeneration (AMD). Thermo-responsive hydrogels derived from N-isopropylacrylamide (NIPAAm) and cross-linked with poly(ethylene glycol) (PEG) poly(L-Lactic acid) (PLLA) copolymer were synthesized via free-radical polymerization. These materials were investigated for (a) phase change behavior, (b) in-vitro degradation, (c) capacity for controlled drug delivery, and (d) biocompatibility. The volume-phase transition temperature (VPTT) of the PNIPAAm- co-PEG-b-PLLA hydrogels was adjusted using hydrophilic and hydrophobic moieties so that it is ca. 33°C. These hydrogels did not initially show evidence of degradation at 37°C due to physical cross-links of collapsed PNIPAAm. Only after addition of glutathione chain transfer agents (CTA)s to the precursor did the collapsed hydrogels become fully soluble at 37°C. CTAs significantly affected the release kinetics of biomolecules; addition of 1.0 mg/mL glutathione to 3 mM cross-linker accelerated hydrogel degradation, resulting in 100% release in less than 2 days. This work also explored the effect of PEGylation in order to tether biomolecules to the polymer matrix. It was demonstrated that non-site-specific PEGylation can postpone the burst release of solutes (up to 10 days in hydrogels with 0.5 mg/mL glutathione). Cell viability assays showed that at least two 20-minute buffer extraction steps were needed to remove cytotoxic elements from the hydrogels. Clinically-used therapeutic biomolecules LucentisRTM and AvastinRTM were demonstrated to be both stable and bioactive after release form PNIPAAm-co-PEG-b-PLLA hydrogels. The thermo-responsive hydrogels presented here offer a promising platform for the localized delivery of proteins such as recombinant antibodies.

  8. Effects of cloud-point grafting, chain length, and density of PEG layers on competitive adsorption of ocular proteins

    DEFF Research Database (Denmark)

    Kingshott, P.; Thissen, H.; Griesser, H.J.

    2002-01-01

    The effects of pinning density, chain length, and 'cloud point' (CP) versus non-CP grafting conditions have been studied on the ability of polyethylene glycol (PEG) layers to minimize adsorption from a multicomponent (lysozyme, human serum albumin (HSA), IgG and lactoferrin) protein solution...... density) r.f.g.d. polymer layers. The PEG graft density was varied also by increasing the temperature and salt (K2SO4) content of the grafting solution; it reached a maximum at the CP of the PEGs. The CP reaction conditions were critical for producing PEG layers capable of minimizing protein adsorption. X...... density and chain length are interrelated, but the key factor is optimization of PEG chain density by use of the CP conditions, provided that a sufficient density of pinning sites exists. (C) 2002 Elsevier Science Ltd. Al l rights reserved....

  9. Alginate/PEG based microcarriers with cleavable crosslinkage for expansion and non-invasive harvest of human umbilical cord blood mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chunge [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, No. 92, Weijin Road, Tianjin 300072 (China); Qian, Yufeng [Department of Chemistry and Biochemistry, University of Texas at Austin, 2500 Speedway, Austin, TX 78712 (United States); Zhao, Shuang [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, No. 92, Weijin Road, Tianjin 300072 (China); Yin, Yuji, E-mail: yinyuji@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, No. 92, Weijin Road, Tianjin 300072 (China); Li, Junjie, E-mail: li41308@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, No. 92, Weijin Road, Tianjin 300072 (China); Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, No. 27, Taiping Road, Beijing 100850 (China)

    2016-07-01

    Porous microcarriers are increasingly used to expand and harvest stem cells. Generally, the cells are harvested via proteolytic enzyme treatment, which always leads to damages to stem cells. To address this disadvantage, a series of alginate/PEG (AL/PEG) semi-interpenetrating network microcarriers are prepared in this study. In this AL/PEG system, the chemically cross-linked alginate networks are formed via the reaction between carboxylic acid group of alginate and di-terminated amine groups of cystamine. PEG is introduced to modulate the degradation of microcarriers, which does not participate in this cross-linked reaction, while it interpenetrates in alginate network via physical interactions. In addition, chitosan are coated on the surface of AL/PEG to improve the mechanical strength via the electrostatic interactions. Biocompatible fibronectin are also coated on these microcarriers to modulate the biological behaviors of cells seeded in microcarriers. Results suggest that the size of AL/PEG microcarriers can be modulated via adjusting the contents and molecular weight of PEG. Moreover, the microcarriers are designed to be degraded with cleavage of disulfide crosslinkage. By changing the type and concentration of reductant, the ratio of AL to PEG, and the magnitude of chitosan coating, the degradation ability of AL/PEG microcarriers can be well controlled. In addition, AL/PEG microcarriers can support the attachment and proliferation of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs). More importantly, the expanded hUCB-MSCs can be detached from microcarriers after addition of reductant, which indeed reduce the cell damage caused by proteolytic enzyme treatment. Therefore, it is convinced that AL/PEG based microcarriers will be a promising candidate for large-scale expansion of hUCB-MSCs. - Graphical abstract: Alginate/PEG IPN microcarriers can support the attachment and expansion of hUCB-MSCs. More importantly, the expanded cells can be harvested

  10. Alginate/PEG based microcarriers with cleavable crosslinkage for expansion and non-invasive harvest of human umbilical cord blood mesenchymal stem cells

    International Nuclear Information System (INIS)

    Li, Chunge; Qian, Yufeng; Zhao, Shuang; Yin, Yuji; Li, Junjie

    2016-01-01

    Porous microcarriers are increasingly used to expand and harvest stem cells. Generally, the cells are harvested via proteolytic enzyme treatment, which always leads to damages to stem cells. To address this disadvantage, a series of alginate/PEG (AL/PEG) semi-interpenetrating network microcarriers are prepared in this study. In this AL/PEG system, the chemically cross-linked alginate networks are formed via the reaction between carboxylic acid group of alginate and di-terminated amine groups of cystamine. PEG is introduced to modulate the degradation of microcarriers, which does not participate in this cross-linked reaction, while it interpenetrates in alginate network via physical interactions. In addition, chitosan are coated on the surface of AL/PEG to improve the mechanical strength via the electrostatic interactions. Biocompatible fibronectin are also coated on these microcarriers to modulate the biological behaviors of cells seeded in microcarriers. Results suggest that the size of AL/PEG microcarriers can be modulated via adjusting the contents and molecular weight of PEG. Moreover, the microcarriers are designed to be degraded with cleavage of disulfide crosslinkage. By changing the type and concentration of reductant, the ratio of AL to PEG, and the magnitude of chitosan coating, the degradation ability of AL/PEG microcarriers can be well controlled. In addition, AL/PEG microcarriers can support the attachment and proliferation of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs). More importantly, the expanded hUCB-MSCs can be detached from microcarriers after addition of reductant, which indeed reduce the cell damage caused by proteolytic enzyme treatment. Therefore, it is convinced that AL/PEG based microcarriers will be a promising candidate for large-scale expansion of hUCB-MSCs. - Graphical abstract: Alginate/PEG IPN microcarriers can support the attachment and expansion of hUCB-MSCs. More importantly, the expanded cells can be harvested

  11. Clinical trial: single- and multiple-dose pharmacokinetics of polyethylene glycol (PEG-3350) in healthy young and elderly subjects.

    Science.gov (United States)

    Pelham, R W; Nix, L C; Chavira, R E; Cleveland, M Vb; Stetson, P

    2008-07-01

    The pharmacokinetics of polyethylene glycol 3350 (PEG-3350) have not been fully described because of lack of a sufficiently sensitive analytical method. To describe the pharmacokinetics of PEG-3350 in humans. A highly sensitive, high performance liquid chromatography with mass spectrometry (HPLC/MS/MS) method was developed for PEG-3350 in urine, plasma and faeces with quantification limits of 30 ng/mL, 100 ng/mL and 500 microg/g respectively. Noncompartmental pharmacokinetics methods were used and the effects of gender, age, renal status and dosing frequency were examined after the oral administration of 17 g to healthy volunteers. Peak PEG-3350 plasma concentrations occurred at 2-4 h and declined to nonquantifiable levels usually within 18 h after single and multiple doses, with a half-life of about 4-6 h. Steady state was reached within 5 days of dosing. Mean urinary excretion of the administered dose ranged from 0.19% to 0.25%. Age, gender or mild kidney impairment did not alter the pharmacokinetics of PEG-3350. Mean faecal excretion of the administered dose was 93% in young subjects. For the first time, a highly sensitive assay allowed comprehensive pharmacokinetics studies of PEG-3350 in humans. These studies confirmed that orally administered PEG-3350 is minimally absorbed, rapidly excreted and primarily eliminated via faeces.

  12. Composite porous scaffold of PEG/PLA support improved bone matrix deposition in vitro compared to PLA-only scaffolds.

    Science.gov (United States)

    Bhaskar, Birru; Owen, Robert; Bahmaee, Hossein; Wally, Zena; Sreenivasa Rao, Parcha; Reilly, Gwendolen C

    2018-05-01

    Controllable pore size and architecture are essential properties for tissue-engineering scaffolds to support cell ingrowth colonization. To investigate the effect of polyethylene glycol (PEG) addition on porosity and bone-cell behavior, porous polylactic acid (PLA)-PEG scaffolds were developed with varied weight ratios of PLA-PEG (100/0, 90/10, 75/25) using solvent casting and porogen leaching. Sugar 200-300 µm in size was used as a porogen. To assess scaffold suitability for bone tissue engineering, MLO-A5 murine osteoblast cells were cultured and cell metabolic activity, alkaline phosphatase (ALP) activity and bone-matrix production determined using (alizarin red S staining for calcium and direct red 80 staining for collagen). It was found that metabolic activity was significantly higher over time on scaffolds containing PEG, ALP activity and mineralized matrix production were also significantly higher on scaffolds containing 25% PEG. Porous architecture and cell distribution and penetration into the scaffold were analyzed using SEM and confocal microscopy, revealing that inclusion of PEG increased pore interconnectivity and therefore cell ingrowth in comparison to pure PLA scaffolds. The results of this study confirmed that PLA-PEG porous scaffolds support mineralizing osteoblasts better than pure PLA scaffolds, indicating they have a high potential for use in bone tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1334-1340, 2018. © 2018 Wiley Periodicals, Inc.

  13. Assessment of reinforced poly(ethylene glycol) chitosan hydrogels as dressings in a mouse skin wound defect model

    International Nuclear Information System (INIS)

    Chen, Szu-Hsien; Tsao, Ching-Ting; Chang, Chih-Hao; Lai, Yi-Ting; Wu, Ming-Fung; Chuang, Ching-Nan; Chou, Hung-Chia; Wang, Chih-Kuang; Hsieh, Kuo-Haung

    2013-01-01

    Wound dressings of chitosan are biocompatible, biodegradable, antibacterial and hemostatic biomaterials. However, applications for chitosan are limited due to its poor mechanical properties. Here, we conducted an in vivo mouse angiogenesis study on reinforced poly(ethylene glycol) (PEG)-chitosan (RPC) hydrogels. RPC hydrogels were formed by cross-linking chitosan with PEGs of different molecular weights at various PEG to chitosan ratios in our previous paper. These dressings can keep the wound moist, had good gas exchange capacity, and was capable of absorbing or removing the wound exudate. We examined the ability of these RPC hydrogels and neat chitosan to heal small cuts and full-thickness skin defects on the backs of male Balb/c mice. Histological examination revealed that chitosan suppressed the infiltration of inflammatory cells and accelerated fibroblast proliferation, while PEG enhanced epithelial migration. The RPC hydrogels promoted wound healing in the small cuts and full layer wounds. The optimal RPC hydrogel had a swelling ratio of 100% and a water vapor transmission rate (WVTR) of about 2000 g/m 2 /day. In addition, they possess good mechanical property and appropriate degradation rates. Thus, the optimal RPC hydrogel formulation functioned effectively as a wound dressing and promoted wound healing. Highlights: ► Mouse angiogenesis study on reinforced poly(ethylene glycol)-chitosan (RPC) ► Water vapor transmission rate of about 2000 g/m 2 /day is characteristic of RPC. ► RPC suppressed inflammatory cells and accelerated fibroblast proliferation. ► RPC composed of 1000-RP10C90 can be used as a biomaterial for wound dressing

  14. Assessment of reinforced poly(ethylene glycol) chitosan hydrogels as dressings in a mouse skin wound defect model

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Szu-Hsien [Institute of Polymer Science and Engineering, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei City 10617, Taiwan (China); Tsao, Ching-Ting [Institute of Polymer Science and Engineering, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei City 10617, Taiwan (China); Epithelial Biology Laboratory/Transgenic Mice Core-Laboratory, Department of Anatomy, Chang Gung University, Taoyuan 33302, Taiwan (China); Chang, Chih-Hao [Department of Orthopedics, National Taiwan University Hospital, Taiwan (China); National Taiwan University College of Medicine, No. 1, Jen-Ai Road, Taipei City 10018, Taiwan (China); Lai, Yi-Ting [Department of Chemical Engineering, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei City 10617, Taiwan (China); Wu, Ming-Fung [Animal Medicine Center, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, Taipei City 10018, Taiwan (China); Chuang, Ching-Nan [Institute of Polymer Science and Engineering, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei City 10617, Taiwan (China); Chou, Hung-Chia [Department of Chemical Engineering, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei City 10617, Taiwan (China); Wang, Chih-Kuang, E-mail: ckwang@kmu.edu.tw [Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan (China); Hsieh, Kuo-Haung, E-mail: khhsieh@ntu.edu.tw [Institute of Polymer Science and Engineering, College of Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei City 10617, Taiwan (China)

    2013-07-01

    Wound dressings of chitosan are biocompatible, biodegradable, antibacterial and hemostatic biomaterials. However, applications for chitosan are limited due to its poor mechanical properties. Here, we conducted an in vivo mouse angiogenesis study on reinforced poly(ethylene glycol) (PEG)-chitosan (RPC) hydrogels. RPC hydrogels were formed by cross-linking chitosan with PEGs of different molecular weights at various PEG to chitosan ratios in our previous paper. These dressings can keep the wound moist, had good gas exchange capacity, and was capable of absorbing or removing the wound exudate. We examined the ability of these RPC hydrogels and neat chitosan to heal small cuts and full-thickness skin defects on the backs of male Balb/c mice. Histological examination revealed that chitosan suppressed the infiltration of inflammatory cells and accelerated fibroblast proliferation, while PEG enhanced epithelial migration. The RPC hydrogels promoted wound healing in the small cuts and full layer wounds. The optimal RPC hydrogel had a swelling ratio of 100% and a water vapor transmission rate (WVTR) of about 2000 g/m{sup 2}/day. In addition, they possess good mechanical property and appropriate degradation rates. Thus, the optimal RPC hydrogel formulation functioned effectively as a wound dressing and promoted wound healing. Highlights: ► Mouse angiogenesis study on reinforced poly(ethylene glycol)-chitosan (RPC) ► Water vapor transmission rate of about 2000 g/m{sup 2}/day is characteristic of RPC. ► RPC suppressed inflammatory cells and accelerated fibroblast proliferation. ► RPC composed of 1000-RP10C90 can be used as a biomaterial for wound dressing.

  15. Use of Powder PEG-3350 as a Sole Bowel Preparation

    Science.gov (United States)

    Arora, Manish

    2008-01-01

    Objective: To assess the efficacy of low-volume powder polyethylene glycol (PEG)-3350 as a sole bowel preparation for colonoscopy. Methods: This case series examined 245 consecutive patients (a mixture of inpatients and outpatients undergoing screening colonoscopy) at a hospital endoscopy center over a 2-year period. The patients received powder PEG-3350 in the amount of 204 g dissolved in 32 oz of water and taken in 3 divided doses 1 hour apart with 8 oz of water in between each dose. Colon preparation scores (CPS) were used to assess the quality of colon cleansing. The results obtained from the 245 patients were collated and compared to those of patients receiving sodium phosphate, the historical control. Results: The mean CPS was calculated to be 3.43, with a standard deviation of 1.12. Of the 245 patients, 92 were scored with a grade of 4, and 5 patients had incomplete colonoscopies secondary to failure of bowel preparation (CPS=0). Among the remaining patients, 22 and 26 were graded as poor (CPS=1) or fair (CPS=2) bowel preparations, respectively. Conclusion: The low-volume powder PEG-3350 formula used in our case series showed effective colon cleansing and may be considered for use as a sole bowel preparation. PMID:21960925

  16. Modification of titanium surfaces by adding antibiotic-loaded PHB spheres and PEG for biomedical applications.

    Science.gov (United States)

    Rodríguez-Contreras, Alejandra; Marqués-Calvo, María Soledad; Gil, Francisco Javier; Manero, José María

    2016-08-01

    Novel researches are focused on the prevention and management of post-operative infections. To avoid this common complication of implant surgery, it is preferable to use new biomaterials with antibacterial properties. Therefore, the aim of this work is to develop a method of combining the antibacterial properties of antibiotic-loaded poly(3-hydroxybutyrate) (PHB) nano- and micro-spheres and poly(ethylene glycol) (PEG) as an antifouling agent, with titanium (Ti), as the base material for implants, in order to obtain surfaces with antibacterial activity. The Ti surfaces were linked to both PHB particles and PEG by a covalent bond. This attachment was carried out by firstly activating the surfaces with either Oxygen plasma or Sodium hydroxide. Further functionalization of the activated surfaces with different alkoxysilanes allows the reaction with PHB particles and PEG. The study confirms that the Ti surfaces achieved the antibacterial properties by combining the antibiotic-loaded PHB spheres, and PEG as an antifouling agent.

  17. Influence of PEG coating on optical and thermal response of gold nanoshperes and nanorods

    Science.gov (United States)

    Chen, Qin; Ren, Yatao; Qi, Hong; Ruan, Liming

    2018-06-01

    PEGylation is widely applied as a surface modification method for nanoparticles in biomedical applications to improve their biological properties, including biocompatibility and immunogenicity. In most of its biomedical applications, nanoparticles are served as optical or thermal contrast agents. Therefore, the impact of poly (ethylene glycol) (PEG) coating thickness on the optical and thermal properties of nanoparticles needs to be further investigated. In the present work, we studied two kinds of commonly used nanoparticles, including nanosphere and nanorod. The temperature and electric fields are obtained for nanoparticles with different PEG coating thicknesses. It is found that the change of PEG coating thickness on gold nanospheres only has impact on the absolute value of maximum absorption and scattering efficiencies, which barely influences the LSPR wavelength λmax and other optical and thermal characteristics. In contrast, for nanorod, the maximum efficiencies are barely influenced by the variation of PEG coating thickness. On the other hand, the localized surface plasmon resonance wavelength has an evident red shift with the increasing of PEG coating thickness. The maximum absorption efficiency is a way to evaluate the energy dissipation rate, which decides the scale of the heat source induced by nanoparticles. These findings are crucial for the accurate prediction of optical and thermal properties of nanoparticles in biomedical application. The present work also presents a possible way to manipulate the optical and thermal behaviors of nanoparticles in the application of biomedicine without changing the morphology of nanoparticles.

  18. Synthesized of PEG-6000 coated MgFe2O4 nanoparticles based on natural iron sand by co-precipitation method

    Science.gov (United States)

    Setiadi, E. A.; Simbolon, S.; Saputra, A. S. P.; Marlianto, E.; Djuhana; Kurniawan, C.; Yunus, M.; Sebayang, P.

    2018-02-01

    The polymer coated Magnesium Ferrite nanoparticles (MgFe2O4) based on natural iron sand, Mg(CH3COO)2.4H2O, and PEG-6000 have been successfully prepared by co-precipitation method. The mass variation of PEG-6000 content was from 0 to 12 gram. It was prepared at synthesize temperature of 70°C. The PEG coating reduced the effect of agglomeration, so the coercivity value can be closed to soft magnets. The nanoparticle of synthesized has MgFe2O4 single phase and cubic spinel structure. The bonding of MgFe2O4 and PEG-6000 as a coating material was confirmed by FTIR curve. The MgFe2O4 density decreased with the increasing of PEG 6000 content. On the other hand, the coercivity value was slightly reduced as the addition of PEG-6000, with the lowest value was obtained on 8 gram PEG content. The optimum condition is obtained at addition of 8 gram PEG 6000 to MgFe2O4, with coercivity, saturation, and remanence are 198.41 Oe, 52.53 emu/g, and 8.51 emu/g, respectively. So that, the sample is widely used as absorbance material of heavy metal.

  19. PEG 3350 (Transipeg) versus lactulose in the treatment of childhood functional constipation: a double blind, randomised, controlled, multicentre trial

    Science.gov (United States)

    Voskuijl, W; de Lorijn, F; Verwijs, W; Hogeman, P; Heijmans, J; Mäkel, W; Taminiau, J; Benninga, M

    2004-01-01

    Background: Recently, polyethylene glycol (PEG 3350) has been suggested as a good alternative laxative to lactulose as a treatment option in paediatric constipation. However, no large randomised controlled trials exist evaluating the efficacy of either laxative. Aims: To compare PEG 3350 (Transipeg: polyethylene glycol with electrolytes) with lactulose in paediatric constipation and evaluate clinical efficacy/side effects. Patients: One hundred patients (aged 6 months–15 years) with paediatric constipation were included in an eight week double blinded, randomised, controlled trial. Methods: After faecal disimpaction, patients encopresis frequency/week and successful treatment after eight weeks. Success was defined as a defecation frequency ⩾3/week and encopresis ⩽1 every two weeks. Secondary outcome measures were side effects after eight weeks of treatment. Results: A total of 91 patients (49 male) completed the study. A significant increase in defecation frequency (PEG 3350: 3 pre v 7 post treatment/week; lactulose: 3 pre v 6 post/week) and a significant decrease in encopresis frequency (PEG 3350: 10 pre v 3 post/week; lactulose: 8 pre v 3 post/week) was found in both groups (NS). However, success was significantly higher in the PEG group (56%) compared with the lactulose group (29%). PEG 3350 patients reported less abdominal pain, straining, and pain at defecation than children using lactulose. However, bad taste was reported significantly more often in the PEG group. Conclusions: PEG 3350 (0.26 (0.11) g/kg), compared with lactulose (0.66 (0.32) g/kg), provided a higher success rate with fewer side effects. PEG 3350 should be the laxative of first choice in childhood constipation. PMID:15479678

  20. Free radical scavenging injectable hydrogels for regenerative therapy

    Energy Technology Data Exchange (ETDEWEB)

    Komeri, Remya [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India); Thankam, Finosh Gnanaprakasam [Dept. of Biomedical Sciences, Creighton University, 2500 California Plaza, Omaha NE68178 (United States); Muthu, Jayabalan, E-mail: mjayabalan52@gmail.com [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Polymer Science Division, BMT Wing, Thiruvananthapuram 695 012, Kerala State (India)

    2017-02-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

  1. Free radical scavenging injectable hydrogels for regenerative therapy

    International Nuclear Information System (INIS)

    Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2017-01-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07 kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. - Graphical abstract: Injectable hydrogel with inherent free radical scavenging property for regenerative tissue engineering application. - Highlights: • Novel injectable hydrogel (PEAX-P) is prepared using D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer

  2. Biocompatible and colloidally stabilized mPEG-PE/calcium phosphate hybrid nanoparticles loaded with siRNAs targeting tumors

    OpenAIRE

    Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong; Li, He; Li, Yaogang; Duan, Yourong

    2015-01-01

    Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-?-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average s...

  3. Intracellular targeting of mercaptoundecahydrododecaborate (BSH) to malignant glioma by transferrin-PEG liposomes for boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Doi, Atsushi; Miyatake, Shin-ichi; Iida, Kyouko

    2006-01-01

    Malignant glioma is one of the most difficult tumor to control with usual therapies. In our institute, we select boron neutron capture therapy (BNCT) as an adjuvant radiation therapy after surgical resection. This therapy requires the selective delivery of high concentration of 10 B to malignant tumor tissue. In this study, we focused on a tumor-targeting 10 B delivery system (BDS) for BNCT that uses transferrin-conjugated polyethylene-glycol liposome encapsulating BSH (TF-PEG liposome-BSH) and compared 10 B uptake of the tumor among BSH, PEG liposome-BSH and TF-PEG liposome-BSH. In vitro, we analyzed 10 B concentration of the cultured human U87Δ glioma cells incubated in medium containing 20 μg 10 B/ml derived from each BDS by inductively coupled plasma atomic emission spectrometry (ICP-AES). In vivo, human U87Δ glioma-bearing nude mice were administered with each BDS (35mg 10 B/kg) intravenously. We analyzed 10 B concentration of tumor, normal brain and blood by ICP-AES. The TF-PEG liposome-BSH showed higher absolute concentration more than the other BDS. Moreover, TF-PEG liposome-BSH decreased 10 B concentration in blood and normal tissue while it maintained high 10 B concentration in tumor tissue for a couple of days. This showed the TF-PEG liposome-BSH caused the selective delivery of high concentration of 10 B to malignant tumor tissue. The TF-PEG liposome-BSH is more potent BDS for BNCT to obtain absolute high 10 B concentration and good contrast between tumor and normal tissue than BSH and PEG liposome-BSH. (author)

  4. Structural, spectroscopic and anti-microbial inspection of PEG capped ZnO nanoparticles for biomedical applications

    Science.gov (United States)

    Meshram, J. V.; Koli, V. B.; Kumbhar, S. G.; Borde, L. C.; Phadatare, M. R.; Pawar, S. H.

    2018-04-01

    Zinc oxide (ZnO) nanoparticles (NPs) have a wide range of biomedical applications. Present study demonstrates the new methodology in sol-gel technology for synthesizing Polyethylene glycol (PEG) capped ZnO NPs and its size effect on anti-microbial activity. The reaction time was increased from 1 h to 5 h for the synthesis of ZnO NPs at 130 °C. The size of PEG capped ZnO NPs is increased from 10 to 84 nm by increasing the reaction upto 5 h. The x-ray diffraction studies and transmission electron microscopy analysis reveals the phase purity and hexagonal wurtzite crystal structure with uniform PEG capping on the surface of ZnO NPs. UV–visible spectroscopy exhibits the peak at 366 nm which is attributed to ZnO NPs. No adverse effect is observed in case of absorbance spectroscopy. Further, Fourier transforms infrared spectroscopy and thermo gravimetric analysis depicts the adsorption of PEG molecules on the ZnO NPs surface. The anti-microbial activities for both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria were studied by optical density (OD) mesurement. The remarkable anti-microbial activity was observed for PEG capped ZnO NPs synthesized at 1 h reaction time showing higher activity in comparison with that synthesized from 2 h to 5 h reaction time. The microbial growth was found to be inhibited after 10 h OD measurement for both the bacteria. The anti-microbial activity may be attributed to the generation of ROS and H2O2. However, these generated species plays a vital role in inhibition of microbial growth. Hence, PEG capped ZnO NPs has promising biomedical applications.

  5. Application of 10B entrapped PEG-liposome to boron neutron-capture therapy for pancreatic cancer model in vivo

    International Nuclear Information System (INIS)

    Yanagie, H.; Eriguchi, M.; Maruyama, K.; Takizawa, T.; Ishida, O.; Ogura, K.; Matsumoto, T.; Sakurai, Y.; Kobayashi, T.; Ono, K.; Rant, J.; Skvarc, J.; Ilic, R.; Shinohara, A.; Chiba, M.; Kobayashi, H.

    1999-01-01

    The cytotoxic effects for tumor were evaluated with intravenous injection 10 B PEG-liposome (Stealth liposome) on human pancreatic carcinoma wenografts in nude mice with thermal neutron irradiation. After thermal neutron irradiation of mice injected with 10 B bare-liposome or 10 B PEG liposome, AsPC-1 tumour growth was suppressed relative to controls. Injection of 10 B PEG-liposome caused the greatest tumour suppression with thermal neutron irradiation in vivo. These results suggest that intravenous injection of 10 B PEG-liposome can increase the retention of 10 B atoms by tumor cells, causing tumor growth suppression in vivo upon thermal neutron irradiation.(author)

  6. How Do Polyethylene Glycol and Poly(sulfobetaine) Hydrogel Layers on Ultrafiltration Membranes Minimize Fouling and Stay Stable in Cleaning Chemicals?

    KAUST Repository

    Le, Ngoc Lieu

    2017-05-18

    We compare the efficiency of grafting polyethylene glycol (PEG) and poly(sulfobetaine) hydrogel layer on poly(ether imide) (PEI) hollow-fiber ultrafiltration membrane surfaces in terms of filtration performance, fouling minimization and stability in cleaning solutions. Two previously established different methods toward the two different chemistries (and both had already proven to be suited to reduce fouling significantly) are applied to the same PEI membranes. The hydrophilicity of PEI membranes is improved by the modification, as indicated by the change of contact angle value from 89° to 68° for both methods, due to the hydration layer formed in the hydrogel layers. Their pure water flux declines because of the additional permeation barrier from the hydrogel layers. However, these barriers increase protein rejection. In the exposure at a static condition, grafting PEG or poly(sulfobetaine) reduces protein adsorption to 23% or 11%, respectively. In the dynamic filtration, the hydrogel layers minimizes the flux reduction and increases the reversibility of fouling. Compared to the pristine PEI membrane that can recover its flux to 42% after hydraulic cleaning, the PEG and poly(sulfobetaine) grafted membranes can recover their flux up to 63% and 94%, respectively. Stability tests show that the poly(sulfobetaine) hydrogel layer is stable in acid, base and chlorine solutions, whereas the PEG hydrogel layer suffers alkaline hydrolysis in base and oxidation in chlorine conditions. With its chemical stability and pronounced capability of minimizing fouling, especially irreversible fouling, protective poly(sulfobetaine) hydrogel layers have great potential for various membrane-based applications.

  7. Clinical Trial of AC105 (Mg/PEG) for Treatment of Acute Spinal Cord Injury (SCI). Phase 2

    Science.gov (United States)

    2013-10-01

    glycol with a molecular weight of 3350 Daltons ( PEG 3350 ), is manufactured by Dow Chemical Company and complies with NF, FCC and EurPh requirements...Mg/ PEG ) for Treatment of Acute Spinal Cord Injury (SCI) PRINCIPAL INVESTIGATOR: Andrew Blight, PhD RECIPIENT: Acorda Therapeutics...of AC105 (Mg/ PEG ) for Treatment of Acute Spinal Cord Injury (SCI) 5b. GRANT NUMBER W81XWH-12-2 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  8. Synthesis of PEG-Iodine-Capped Gold Nanoparticles and Their Contrast Enhancement in In Vitro and In Vivo for X-Ray/CT

    International Nuclear Information System (INIS)

    Sun-Hee, K.; Eun-Mi, K.; Chang-Moon, L.; Dong, W.K.; Seok, T.L.; Myung-Hee, S.; Hwan-Jeong, J.

    2012-01-01

    We designed gold nanoparticles (AuNPs) capped with iodine and polyethylene glycol (PEG) to provide effective enhancement for X-ray CT imaging. The methoxy PEG-iodine-capped AuNPs were prepared through the chemisorption of iodine and substitution of methoxy PEG-SH onto the surface of gold nanoparticles, and severe aggregation in TEM was not observed. The binding energies of Au 4f 7/2 and I 3d 5/2 of the methoxy PEG-iodine-capped AuNPs were obtained as 84.1 eV and 619.3 eV, respectively. The binding energy shift of methoxy PEG-iodine-capped AuNPs would be resulted from the chemisorption between gold nanoparticles and iodine atoms. The methoxy PEG-iodine-capped AuNPs have higher enhancement compared to PEG-capped gold nanoparticles in the same amount of gold in vitro. After postinjection of methoxy PEG-iodine-capped AuNPs into the mice, dramatic contrast enhancement at the heart, aorta, liver, and kidney was observed, this was maintained up to 5 days, and there was no evidence of apparent toxicity. In conclusion, methoxy PEG-iodine-capped AuNPs might be a good candidate as a CT contrast agent for blood pool imaging, and this will also contribute to the prolongation of a blood circulation time for X-ray CT imaging.

  9. Polyethylene glycol (PEG-400: An efficient medium for the synthesis of 1,2-disubstituted benzimidazoles

    Directory of Open Access Journals (Sweden)

    Raja Sekhar Mekala

    2015-12-01

    Full Text Available Polyethylene glycol (PEG-400 was found to be an inexpensive, non-toxic, and effective medium for the one-pot synthesis of 1,2-disubstituted benzimidazoles in excellent yields. Eco-friendliness, low cost, high yields, and recyclability of the PEG-400 are the important features of this protocol.

  10. Vitamin D in addition to peg-interferon-alpha/ribavirin in chronic hepatitis C virus infection: ANRS-HC25-VITAVIC study.

    Science.gov (United States)

    Terrier, Benjamin; Lapidus, Nathanael; Pol, Stanislas; Serfaty, Lawrence; Ratziu, Vlad; Asselah, Tarik; Thibault, Vincent; Souberbielle, Jean-Claude; Carrat, Fabrice; Cacoub, Patrice

    2015-05-14

    To investigate if correction of hypovitaminosis D before initiation of Peg-interferon-alpha/ribavirin (PegIFN/RBV) therapy could improve the efficacy of PegIFN/RBV in previously null-responder patients with chronic genotype 1 or 4 hepatitis C virus (HCV) infection. Genotype 1 or 4 HCV-infected patients with null response to previous PegIFN/RBV treatment and with hypovitaminosis D (vitamin D level was 15 ng/mL (range: 7-28). In modified intention-to-treat analysis, 29 patients who received at least one dose of PegIFN/RBV were included in the analysis. All patients except one normalized their vitamin D serum levels. The rate of early virologic response was 0/29 (0%). The rate of HCV RNA vitamin D to PegIFN/RBV does not improve the rate of early virologic response in previously null-responders with chronic genotype 1 or 4 HCV infection.

  11. Curcumin-Loaded Blood-Stable Polymeric Micelles for Enhancing Therapeutic Effect on Erythroleukemia.

    Science.gov (United States)

    Gong, Feirong; Chen, Dan; Teng, Xin; Ge, Junhua; Ning, Xianfeng; Shen, Ya-Ling; Li, Jian; Wang, Shanfeng

    2017-08-07

    Curcumin has high potential in suppressing many types of cancer and overcoming multidrug resistance in a multifaceted manner by targeting diverse molecular targets. However, the rather low systemic bioavailability resulted from its poor solubility in water and fast metabolism/excretion in vivo has hampered its applications in cancer therapy. To increase the aqueous solubility of curcumin while retaining the stability in blood circulation, here we report curcumin-loaded copolymer micelles with excellent in vitro and in vivo stability and antitumor efficacy. The two copolymers used for comparison were methoxy-poly(ethylene glycol)-block-poly(ε-caprolactone) (mPEG-PCL) and N-(tert-butoxycarbonyl)-l-phenylalanine end-capped mPEG-PCL (mPEG-PCL-Phe(Boc)). In vitro cytotoxicity evaluation against human pancreatic SW1990 cell line showed that the delivery of curcumin in mPEG-PCL-Phe(Boc) micelles to cancer cells was efficient and dosage-dependent. The pharmacokinetics in ICR mice indicated that intravenous (i.v.) administration of curcumin/mPEG-PCL-Phe(Boc) micelles could retain curcumin in plasma much better than curcumin/mPEG-PCL micelles. Biodistribution results in Sprague-Dawley rats also showed higher uptake and slower elimination of curcumin into liver, lung, kidney, and brain, and lower uptake into heart and spleen of mPEG-PCL-Phe(Boc) micelles, as compared with mPEG-PCL micelles. Further in vivo efficacy evaluation in multidrug-resistant human erythroleukemia K562/ADR xenograft model revealed that i.v. administration of curcumin-loaded mPEG-PCL-Phe(Boc) micelles significantly delayed tumor growth, which was attributed to the improved stability of curcumin in the bloodstream and increased systemic bioavailability. The mPEG-PCL-Phe(Boc) micellar system is promising in overcoming the key challenge of curcumin's to promote its applications in cancer therapy.

  12. Effect of spatial distribution of wax and PEG-isocyanate on the morphology and hydrophobicity of starch films.

    Science.gov (United States)

    Muscat, Delina; Adhikari, Raju; Tobin, Mark J; McKnight, Stafford; Wakeling, Lara; Adhikari, Benu

    2014-10-13

    This study proposes a novel method for improving surface hydrophobicity of glycerol plasticized high amylose (HAG) films. We used polyethylene glycol isocyanate (PEG-iso) crosslinker to link HAG and three natural waxes (beeswax, candelilla wax and carnauba wax) to produce HAG+wax+PEG-iso films. The spatial distributions of wax and PEG-iso across the thickness of these films were determined using Synchrotron-based Fourier transform infrared spectroscopy. The hydrophobicity and surface morphology of the films were determined using contact angle (CA) and scanning electron microscopic measurements, respectively. The distribution patterns of wax and the PEG-iso across the thickness of the film, and the nature of crystalline patterns formed on the surface of these films were found to be the key factors affecting surface hydrophobicity. The highest hydrophobicity (CA >90°) was created when the PEG-iso was primarily distributed in the interior of the films and a hierarchical circular pinnacle structure of solidified wax was formed on the surface. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Risks of PEG tube placement in patients with cirrhosis-associated ascites

    Directory of Open Access Journals (Sweden)

    Al-Abboodi Y

    2017-09-01

    Full Text Available Yasir Al-Abboodi,1 Ali Ridha,2 Matthew Fasullo,3 Tarek H Naguib4 1Internal Medicine Department, Saint Davis Round Rock Medical Centre, Round Rock, TX, USA, 2Internal Medicine Department, University of Arkansas for Medical Science, Little Rock, AR, USA, 3Internal Medicine Department, Umass Memorial Medical Center, Worcester, MA, USA, 4Internal Medicine Department, Texas Tech University Health and Sciences Center, Amarillo, TX, USA Abstract: This study examined the safety of placing percutaneous endoscopic gastrostomy (PEG tube in people with liver cirrhosis. The target population was further subdivided into people with ascites (case group and people without ascites (control. We compare the morbidity and the mortality difference of PEG placement in cirrhotic patients with ascites vs cirrhotic patients without ascites. We then examined multiple factors including sex, race, chronic illness including hypertension, congestive heart failure, and others and their influence on the inpatient mortality of all cirrhotic patients who had PEG placement. A total of 38,175 inpatient PEG tube placements were identified. Only 583 patients out of 38,175 had a history of cirrhosis. One hundred seven had ascites and the rest did not. Mean age of the patients was 61.14 years. Patient demography included (65.2% male and the rest were female, 359 were white (64.4%, 90 black (14.8%, 84 Hispanic (13.7%, 23 Asians (3.3%, 7 Native Americans (0.4%, and 20 others (3.5%. Complications from PEG procedure in cirrhosis with ascites vs non-ascites included bleeding of 4 (0.8% vs 2 (1.9% (P=0.35, surgical site infection 2 (0.4% vs 1 (0.9% (P=0.51, and urinary tract infection 105 (22.1% vs 34 (23.8% (P=0.34, respectively. There was no colonic injury in either group. The total inpatient mortality was 75 out of the 583. Fifty-six (11.8% were in the ascites group and 19 (17.8% in the non-ascites group (P=0.097. Factors including ascites, postsurgical bleeding, and surgical site

  14. THERMODYNAMICS OF CESIUM EXTRACTION FROM ACIDIC MEDIA BY HCCD and PEG

    International Nuclear Information System (INIS)

    Herbst, R. Scott; Peterman, Dean R.; Zalupski, Peter R.; Nash, Ken L.; Tillotson, Richard D.; Delmau, Laetitia H.

    2010-01-01

    This is a companion study to previous publications which expands the understanding of cesium extraction from nitrate media using chlorinated cobalt dicarbollide (HCCD) dissolved in the polar phenyl trifluoromethyl sulfone (FS-13) diluent. First, it is verified that the system is based solely on cation exchange between H+ and Cs+ and that NO3- does not intervene, i.e., that the apparent nitrate dependency is merely an artifact of solution non-idealities. Next, the enthalpy and entropy of the system were determined using appropriate corrections in the van't Hoff analysis and are in excellent agreement with independently published calorimetry results. Finally, the extraction of Cs by the system containing both HCCD and polyethylene glycol (PEG) in FS-13 was characterized by the determination the species produced in the organic and aqueous phases and it is further demonstrated that synergistic extraction of Cs by HCCD and PEG does not occur. Although there is a definite interaction between HCCD and PEG, and it is well established that this interaction is responsible for the extraction of Sr, this association is actually antagonist with respect to the extraction of Cs.

  15. Antifouling activities of β-cyclodextrin stabilized peg based silver nanocomposites

    Science.gov (United States)

    Punitha, N.; Saravanan, P.; Mohan, R.; Ramesh, P. S.

    2017-01-01

    Self-polishing polymer composites which release metal biocide in a controlled rate have been widely used in the design of antimicrobial agents and antifouling coatings. The present work focuses on the environmental friendly green synthesis of PEG based SNCs and their application to biocidal activity including marine biofouling. Biocompatible polymer β-CD and adhesive resistance polymer PEG were used to functionalize the SNPs and the as synthesized SNCs exhibit excellent micro fouling activities. The structural and optical properties were confirmed by XRD and UV-visible techniques respectively. The particle surface and cross sectional characteristics were examined by SEM-EDS, HR-TEM, AFM and FTIR. The surface potential was evaluated using ZP analysis and assessment of antibiofouling property was investigated using static immersion method.

  16. Phase 1 Trial of Subcutaneous rAvPAL-PEG in Subjects with Phenylketonuria

    Science.gov (United States)

    Longo, Nicola; Harding, Cary O.; Burton, Barbara K.; Grange, Dorothy K.; Vockley, Jerry; Wasserstein, Melissa; Rice, Gregory M.; Musson, Donald G.; Gu, Zhonghua; Sile, Saba

    2014-01-01

    Objective Phenylketonuria is an inherited disease caused by impaired activity of phenylalanine hydroxylase, the enzyme that converts phenylalanine to tyrosine, leading to accumulation of phenylalanine and subsequent neurocognitive dysfunction. A phenylalanine-restricted diet initiated early in life can ameliorate the toxic effects of phenylalanine. However, the diet is onerous and compliance is extremely difficult. Phenylalanine ammonia lyase (PAL) is a prokaryotic enzyme that converts phenylalanine to ammonia and trans-cinnamic acid. This Phase 1, multicenter clinical trial evaluated the safety, tolerability, pharmacokinetics and efficacy of rAvPAL-PEG (recombinant Anabaena variabilis PAL produced in E. coli conjugated with polyethylene glycol [PEG] to reduce immunogenicity) in reducing phenylalanine levels in subjects with phenylketonuria. Methods Single subcutaneous injections of rAvPAL-PEG in escalating doses (0·001, 0·003, 0·01, 0·03, and 0·1 mg/kg) were administered to 25 adults with phenylketonuria recruited from those attending metabolic clinics in North America whose blood phenylalanine concentrations were ≥600 μmol/L. Results The most frequently reported adverse events were injection-site reactions and dizziness. Reactions were self-limited without sequelae. During the trial, two subjects had adverse reactions to intramuscular (IM) medroxyprogesterone acetate, a drug containing polyethylene glycol as an excipient. Three subjects developed a generalized skin rash at the highest rAvPAL-PEG dose (0·1 mg/kg). Drug levels peaked ∼5 days after the injection. Treatment was effective in reducing blood phenylalanine in all five subjects receiving the highest dose (0·1 mg/kg, mean percent change of -58 from baseline), with a nadir ∼6 days after injection and inverse correlation between drug and phenylalanine concentrations in plasma. Phenylalanine concentrations returned to near-baseline levels ∼20 days after the single injection. Conclusions

  17. Thermosensitive mPEG-b-PA-g-PNIPAM comb block copolymer micelles: effect of hydrophilic chain length and camptothecin release behavior.

    Science.gov (United States)

    Yang, Xiao-Li; Luo, Yan-Ling; Xu, Feng; Chen, Ya-Shao

    2014-02-01

    Block copolymer micelles are extensively used as drug controlled release carriers, showing promising application prospects. The comb or brush copolymers are especially of great interest, whose densely-grafted side chains may be important for tuning the physicochemical properties and conformation in selective solvents, even in vitro drug release. The purpose of this work was to synthesize novel block copolymer combs via atom transfer radical polymerization, to evaluate its physicochemical features in solution, to improve drug release behavior and to enhance the bioavailablity, and to decrease cytotoxicity. The physicochemical properties of the copolymer micelles were examined by modulating the composition and the molecular weights of the building blocks. A dialysis method was used to load hydrophobic camptothecin (CPT), and the CPT release and stability were detected by UV-vis spectroscopy and high-performance liquid chromatography, and the cytotoxicity was evaluated by MTT assays. The copolymers could self-assemble into well-defined spherical core-shell micelle aggregates in aqueous solution, and showed thermo-induced micellization behavior, and the critical micelle concentration was 2.96-27.64 mg L(-1). The micelles were narrow-size-distribution, with hydrodynamic diameters about 128-193 nm, depending on the chain length of methoxy polyethylene glycol (mPEG) blocks and poly(N-isopropylacrylamide) (PNIPAM) graft chains or/and compositional ratios of mPEG to PNIPAM. The copolymer micelles could stably and effectively load CPT but avoid toxicity and side-effects, and exhibited thermo-dependent controlled and targeted drug release behavior. The copolymer micelles were safe, stable and effective, and could potentially be employed as CPT controlled release carriers.

  18. Enhanced delivery of biodegradable mPEG-PLGA-PLL ...

    Indian Academy of Sciences (India)

    ... effectively down-regulate the mRNA and protein expression of PDGF‐BB thanNPs plus US (P=0.014 and P=0.007, respectively). Histology showed no evident tissue damage after UTMDmediatedNPs loading siRNA transfection. UTMD could be used safely to enhance the delivery of mPEG-PLGAPLLNPs loading siRNA ...

  19. Microphase separation behavior on the surfaces of PEG-MDI-PDMS multiblock copolymer coatings

    International Nuclear Information System (INIS)

    Fang Hongxia; Zhou Shuxue; Wu Limin

    2006-01-01

    A series of poly(ethylene glycol)(PEG)-4,4'-diphenylmethanediisocyanate(MDI)-poly(dimethylsiloxane) (PDMS) multiblock copolymers were synthesized by employing two-step growth polymerization technique. Atomic force microscopy (AFM) observed nanoscopically well-organized phase-separated surfaces consisting of hydrophilic domain from PEG and MDI segments and hydrophobic domain from PDMS segments even with 50 wt.% PDMS in the copolymer, and the multiblock copolymer coatings presented a surface free energy of as low as 6-8 mN m -1

  20. Retreatment with peg-interferon and ribavirin in patients with chronic hepatitis C virus genotype 2 or 3 infection with prior relapse

    DEFF Research Database (Denmark)

    Lagging, Martin; Rembeck, Karolina; Rauning Buhl, Mads

    2013-01-01

    Uncertainty remains regarding the efficacy of retreatment with current standard-of-care peg-interferon (peg-IFN) and ribavirin among patients infected with hepatitis C virus (HCV) genotypes 2 or 3 with relapse after prior therapy.......Uncertainty remains regarding the efficacy of retreatment with current standard-of-care peg-interferon (peg-IFN) and ribavirin among patients infected with hepatitis C virus (HCV) genotypes 2 or 3 with relapse after prior therapy....

  1. Management of type II dens invaginatus and peg laterals with spacing of maxillary anteriors

    Directory of Open Access Journals (Sweden)

    Tina Puthen Purayil

    2015-01-01

    Full Text Available A case of peg-shaped lateral with dens invaginatus (DI and midline diastema affecting maxillary incisors in a 32-year old female patient is discussed. This clinical report describes the endodontic management of DI in tooth #12, esthetic correction of peg laterals and diastema with all ceramic restorations. Satisfactory results were achieved esthetically following treatment and gave the patient a new confident smile.

  2. Biodegradable PLGA-b-PEG polymeric nanoparticles: synthesis, properties, and nanomedical applications as drug delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, Erica; Comes Franchini, Mauro, E-mail: mauro.comesfranchini@unibo.it [University of Bologna, Dipartimento di Chimica Industriale Toso Montanari (Italy)

    2012-12-15

    During the past decades many synthetic polymers have been studied for nanomedicine applications and in particular as drug delivery systems. For this purpose, polymers must be non-toxic, biodegradable, and biocompatible. Polylactic-co-glycolic acid (PLGA) is one of the most studied polymers due to its complete biodegradability and ability to self-assemble into nanometric micelles that are able to entrap small molecules like drugs and to release them into body in a time-dependent manner. Despite fine qualities, using PLGA polymeric nanoparticles for in vivo applications still remains an open challenge due to many factors such as poor stability in water, big diameter (150-200 nm), and the removal of these nanocarriers from the blood stream by the liver and spleen thus reducing the concentration of drugs drastically in tumor tissue. Polyethylene glycol (PEG) is the most used polymers for drug delivery applications and the first PEGylated product is already on the market for over 20 years. This is due to its stealth behavior that inhibits the fast recognition by the immune system (opsonization) and generally leads to a reduced blood clearance of nanocarriers increasing blood circulation time. Furthermore, PEG is hydrophilic and able to stabilize nanoparticles by steric and not ionic effects especially in water. PLGA-PEG block copolymer is an emergent system because it can be easily synthesized and it possesses all good qualities of PLGA and also PEG capability so in the last decade it arose as one of the most promising systems for nanoparticles formation, drug loading, and in vivo drug delivery applications. This review will discuss briefly on PLGA-b-PEG synthesis and physicochemical properties, together with its improved qualities with respect to the single PLGA and PEG polymers. Moreover, we will focus on but in particular will treat nanoparticles formation and uses as new drug delivery system for nanomedical applications.

  3. Physicochemical characterization of 3,6-diHydroxyflavone binding BSA immobilized on PEG-coated silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Voicescu, Mariana, E-mail: voicescu@icf.ro [Institute of Physical Chemistry “Ilie Murgulescu” of the Romanian Academy (Romania); Ionescu, Sorana [University of Bucharest, Department of Physical Chemistry (Romania); Calderon-Moreno, Jose M. [Institute of Physical Chemistry “Ilie Murgulescu” of the Romanian Academy (Romania); Nistor, Cristina L. [National R& D Institute for Chemistry and Petrochemistry ICECHIM, Polymer Department (Romania)

    2017-02-15

    Studies based on silver nanoparticles (SNPs) and polyethylene glycols (PEGs) are mainly in the pharmaceutical field, with PEG as good “vehicle” to transport protein-based drugs. In this work, physicochemical characteristics of 3,6-diHydroxyflavone (3,6-diHF) binding bovine serum albumin (BSA) on PEG (Tween20, L64, and Myrj52)-coated SNPs have been investigated by steady-state and time-resolved fluorescence spectroscopy. These interactions give rise to the formation of intermolecular and intramolecular H bonds. As a subject of interest, the effect of temperature (30–60 °C) on the H bonds was studied by steady-state fluorescence. The size distribution and zeta potential of SNPs were determined by dynamic light scattering (DLS). Scanning electron microscopy (SEM) analysis revealed the spherical nature of particles with average diameter ~40–80 nm. The structure, stability, dynamics, and conformational changes in adsorbed BSA protein on the PEG-coated SNPs surface have been also investigated by steady-state/lifetime fluorescence and circular dichroism spectroscopy. The results have relevance in the oxidative stress and drug delivery processes.

  4. Physicochemical characterization of 3,6-diHydroxyflavone binding BSA immobilized on PEG-coated silver nanoparticles

    Science.gov (United States)

    Voicescu, Mariana; Ionescu, Sorana; Calderon-Moreno, Jose M.; Nistor, Cristina L.

    2017-02-01

    Studies based on silver nanoparticles (SNPs) and polyethylene glycols (PEGs) are mainly in the pharmaceutical field, with PEG as good "vehicle" to transport protein-based drugs. In this work, physicochemical characteristics of 3,6-diHydroxyflavone (3,6-diHF) binding bovine serum albumin (BSA) on PEG (Tween20, L64, and Myrj52)-coated SNPs have been investigated by steady-state and time-resolved fluorescence spectroscopy. These interactions give rise to the formation of intermolecular and intramolecular H bonds. As a subject of interest, the effect of temperature (30-60 °C) on the H bonds was studied by steady-state fluorescence. The size distribution and zeta potential of SNPs were determined by dynamic light scattering (DLS). Scanning electron microscopy (SEM) analysis revealed the spherical nature of particles with average diameter 40-80 nm. The structure, stability, dynamics, and conformational changes in adsorbed BSA protein on the PEG-coated SNPs surface have been also investigated by steady-state/lifetime fluorescence and circular dichroism spectroscopy. The results have relevance in the oxidative stress and drug delivery processes.

  5. Application of the active flexible fixture with passive RCC function to peg-in-hole task

    International Nuclear Information System (INIS)

    Yamaguchi, Tomomi; Higuchi, Masahiro

    2005-01-01

    This paper describes the application of the active flexible fixture (AFLEF) with passive RCC to the peg-in-hole task on the disk in the X-band accelerator. The AFLEF can fix any work and position the fixed work at short range. In this paper, the 2-dimensional AFLEF is proposed as the simplified type and is provided with passive RCC function to be equipped with dexterity for a peg-in-hole task. As results of the experiment on the peg-in-hole task on the X-band accelerator disks with the AFLEF, we make the ability of the AFLEF for the task clear and also the boundary conditions to the complete task clear. (author)

  6. Thermosensitive Behavior and Antibacterial Activity of Cotton Fabric Modified with a Chitosan-poly(N-isopropylacrylamide Interpenetrating Polymer Network Hydrogel

    Directory of Open Access Journals (Sweden)

    Boxiang Wang

    2016-03-01

    Full Text Available To increase the themosensitive behavior and antibacterial activity of cotton fabric, a series of poly (N-isopropylacrylamide/chitosan (PNIPAAm/Cs hydrogels was synthesized by interpenetrating polymer network (IPN technology using a redox initiator. The IPN PNIPAAm/Cs hydrogel was characterized by Fourier transform infrared spectroscopy (FT-IR, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA. The results indicated that the IPN PNIPAAm/Cs hydrogel has a lower critical solution temperature (LCST at 33 °C. The IPN hydrogel was then used to modify cotton fabric using glutaric dialdehyde (GA as a crosslinking agent following a double-dip-double-nip process. The results demonstrated that the modified cotton fabric showed obvious thermosensitive behavior and antibacterial activity. The contact angle of the modified cotton fabric has a sharp rise around 33 °C, and the modified cotton fabric showed an obvious thermosensitive behavior. The bacterial reduction of modified cotton fabric against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli were more than 99%. This study presents a valuable route towards smart textiles and their applications in functional clothing.

  7. Investigation of bioactivity, biocompatibility and thermal behavior of sol–gel silica glass containing a high PEG percentage

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Renella, R.A.; Papale, F. [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Vecchio Ciprioti, S. [Department of Basic and Applied Science for Engineering, Sapienza University of Rome, Via del Castro Laurenziano 7, Building RM017, I-00161 Rome (Italy)

    2016-04-01

    SiO{sub 2}/PEG organic–inorganic hybrid materials, which contain 60 or 70 weight percentage of PEG, were synthesized by the sol–gel technique. The materials were characterized and subjected to various tests to assess their application in the biomedical field. The evaluation of their morphology by scanning electron microscopy (SEM) confirms the homogeneity of the samples on the nanometer scale. Fourier transform infrared spectroscopy (FT-IR) indicated that the two components of the hybrids (SiO{sub 2} and PEG) are linked by hydrogen bonds. This feature makes them class I hybrids. Simultaneous thermogravimetry/differential thermal analysis (TG/DTA) was used to investigate their thermal behavior and to establish the best temperatures for their pre-treatment. The fundamental properties that a material must have to be used in the biomedical field are biocompatibility and bioactivity. The formation of a hydroxyapatite layer was observed on the hybrid surface by SEM/EDX and FTIR after soaking in simulated body fluid. This indicates that the materials are able to bond to bone tissue. Moreover, the biocompatibility of SiO{sub 2}/PEG hybrids was assessed by performing WST-8 cytotoxicity tests on fibroblast cell NIH 3T3 after 24 h of exposure. The cytotoxicity tests highlight that the cell viability is affected by the polymer percentage. The results showed that the synthesized materials were bioactive and biocompatible. Therefore, the results obtained are encouraging for the use of the obtained hybrids in dental or orthopedic applications. - Highlights: • SiO{sub 2}/PEG hybrid biomaterials synthesized by sol–gel method at high PEG percentage • Chemical, thermal and morphological characterization of hybrid materials • Biological characterizations with WST-8 cytotoxicity tests • Bioactivity characterizations of hybrid materials with high PEG percentage.

  8. Improving Tumor Uptake and Pharmacokinetics of 64Cu-Labeled Cyclic RGD Peptide Dimers with Gly3 and PEG4 Linkers

    OpenAIRE

    Shi, Jiyun; Kim, Young-Seung; Zhai, Shizhen; Liu, Zhaofei; Chen, Xiaoyuan; Liu, Shuang

    2009-01-01

    Radiolabeled cyclic RGD (Arg-Gly-Asp) peptides represent a new class of radiotracers with potential for the early tumor detection and non-invasive monitoring of tumor metastasis and therapeutic response in cancer patients. This report describes the synthesis of two cyclic RGD peptide dimer conjugates, DOTA-PEG4-E[PEG4-c(RGDfK)]2 (DOTA-3PEG4-dimer: DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; PEG4 = 15-amino-4,7,10,13-tetraoxapentadecanoic acid) and DOTA-G3-E[G3-c(RGDfK)]2 ...

  9. Tolerability, safety, and efficacy of PEG 3350 as a 1-day bowel preparation in children.

    Science.gov (United States)

    Walia, Ritu; Steffen, Rita; Feinberg, Lisa; Worley, Sarah; Mahajan, Lori

    2013-02-01

    The aim of the study was to evaluate the tolerability, safety, and efficacy of polyethylene glycol (PEG) 3350 without electrolytes as a 1-day bowel preparation for colonoscopy in children. A prospective study of 45 children undergoing colonoscopy prescribed PEG 3350 without electrolytes mixed with a commercial electrolyte beverage was performed. Patients PEG 3350 without electrolytes mixed in 32 ounces of Gatorade. Patients ≥ 45 kg were given 255 g of PEG 3350 without electrolytes in 64 ounces of Gatorade A basic metabolic panel was performed at the time of the clinic visit and just before colonoscopy. Patients completed a survey related to bowel preparation. Endoscopists graded bowel preparation and noted the proximal extent of the examination. A total of 44 patients (14 ± 3 years) completed the study. One patient was excluded due to protocol breach. All subjects reported the preparation was easy (61%) or tolerable (39%). Adverse events included nausea (34%), abdominal pain (23%), vomiting (16%), abdominal distension (20%), bloating (23%), and dizziness (7%). Although significant changes in serum glucose and CO2 were noted, no therapeutic interventions were indicated. Significant changes in sodium, potassium chloride, blood urea nitrogen, or creatinine did not occur. Colonic preparation was rated as excellent in 23%, good in 52%, fair in 23%, and poor in 2% of patients. Intubation of the ileum was successful in 100%. One-day bowel preparation with high dose PEG 3350 mixed with commercial electrolyte solution is tolerable, safe, and effective in children before colonoscopy.

  10. Effects of PEG tethering chain length of vitamin E TPGS with a Herceptin-functionalized nanoparticle formulation for targeted delivery of anticancer drugs.

    Science.gov (United States)

    Zhao, Jing; Feng, Si-Shen

    2014-03-01

    Drug formulation by ligand conjugated nanoparticles of biodegradable polymers has become one of the most important strategies in drug targeting. We have developed in our previous work nanoparticles of a mixture of two vitamin E TPGS based copolymers PLA-TPGS and TPGS-TOOH with the latter for Herceptin conjugation for targeted delivery of anticancer drugs such as docetaxel to the cancer cells of human epidermal growth factor receptor 2 (HER2) overexpression. In this research, we investigated the effects of the PEG chain length in TPGS, which is in fact a PEGylated vitamin E, on the cellular uptake and cytotoxicity of the drug formulated in the Herceptin-conjugated nanoparticles of PLA-TPGS/TPGS-COOH blend (NPs). Such NPs of PEG1000, PEG2000, PEG3350 and PEG5000, i.e. the PEG of molecule weight 1000, 2000, 3350 and 5000, were prepared by the nanoprecipitation method and characterized for their size and size distribution, drug loading, surface morphology, surface charge and surface chemistry as well as in vitro drug release profile, cellular uptake and cytotoxicity. We found among such nanoparticles, those of PEG1000, i.e. of the shortest PEG tethering chain length, could result in the best therapeutic effects, which are 24.1%, 37.3%, 38.1% more efficient in cellular uptake and 68.1%, 90%, 92.6% lower in IC50 (thus higher in cytotoxicity) than the Herceptin-conjugated nanoparticles of PLA-TPGS/TPGS-COOH blend of PEG2000, PEG3350 and PEG5000 respectively in treatment of SK-BR-3 cancer cells which are of high HER2 overexpression. We provided a theoretical explanation from surface mechanics and thermodynamics for endocytosis of nanoparticles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. PEG-lipid-PLGA hybrid nanoparticles loaded with berberine-phospholipid complex to facilitate the oral delivery efficiency.

    Science.gov (United States)

    Yu, Fei; Ao, Mingtao; Zheng, Xiao; Li, Nini; Xia, Junjie; Li, Yang; Li, Donghui; Hou, Zhenqing; Qi, Zhongquan; Chen, Xiao Dong

    2017-11-01

    The natural product berberine (BBR), present in various plants, arouses great interests because of its numerous pharmacological effects. However, the further development and application of BBR had been hampered by its poor oral bioavailability. In this work, we report on polymer-lipid hybrid nanoparticles (PEG-lipid-PLGA NPs) loaded with BBR phospholipid complex using a solvent evaporation method for enhancing the oral BBR efficiency. The advantage of this new drug delivery system is that the BBR-soybean phosphatidylcholine complex (BBR-SPC) could be used to enhance the liposolubility of BBR and improve the affinity with the biodegradable polymer to increase the drug-loading capacity and controlled/sustained release. The entrapment efficiency of the PEG-lipid-PLGA NPs/BBR-SPC was observed to approach approximately 89% which is more than 2.4 times compared with that of the PEG-lipid-PLGA NPs/BBR. To the best of our knowledge, this is the first report on using polymer material for effective encapsulation of BBR to improve its oral bioavailability. The prepared BBR delivery systems demonstrated a uniform spherical shape, a well-dispersed core-shell structure and a small particle size (149.6 ± 5.1 nm). The crystallographic and thermal analysis has indicated that the BBR dispersed in the PEG-lipid-PLGA NPs matrix is in an amorphous form. More importantly, the enhancement in the oral relative bioavailability of the PEG-lipid-PLGA NPs/BBR-SPC was ∼343% compared with that of BBR. These positive results demonstrated that PEG-lipid-PLGA NPs/BBR-SPC may have the potential for facilitating the oral drug delivery of BBR.

  12. Hepatitis B circulating immune complexes. Characterization by radioimmunoprecipitation - PEG assay (ripega)

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, F; Wattre, P; Dessaint, J P; Capron, A [Institut Pasteur de Lille, 59 - Villeneuve d' Ascq (France)

    1977-04-01

    Incidence of circulating immune complexes (IC) was investigated in carriers of hepatitis B antigen (HBAg) and/or anti-HB antibodies (anti-HBAb). Three methods were used: radiolabelled C1q binding test (C1qBT), complement fixation test (CFT), and optical density (OD) measurement after dissolution of 3% polyethylene glycol (PEG) precipitate of serum. A highly significant correlation was obtained between these three techniques. The level of IC was higher in carriers of HBAg without anti-HBAb than in others. The characterization of HBAg and anti-HBAb in IC was carried out by a new procedure, the radioimmunoprecipitation-PEG assay (RIPEGA). This sensitive and reproducible test was performed by incubation of /sup 125/I-HBAg or /sup 125/I-HBAg with 3% precipitate of the carriers' sera. Separation of free from complexed /sup 125/I-HBAg or /sup 125/I-HBAb was achieved by PEG precipitation. A highly significant correlation was found between the levels of circulating IC evaluated by the C1q-BT and the quantities of HBAg or anti HBAb measured by RIPEGA. RIPEGA was used to quantify HBAg and anti-HBAb present in serum from HBAg and/or anti-HBAb carriers, confirmed by a radioimmunoassay. In preliminary results, RIGPEGA was shown to be more sensitive than classical radioimmunoassay.

  13. Purification of inclusion bodies using PEG precipitation under denaturing conditions to produce recombinant therapeutic proteins from Escherichia coli.

    Science.gov (United States)

    Chen, Huanhuan; Li, Ninghuan; Xie, Yueqing; Jiang, Hua; Yang, Xiaoyi; Cagliero, Cedric; Shi, Siwei; Zhu, Chencen; Luo, Han; Chen, Junsheng; Zhang, Lei; Zhao, Menglin; Feng, Lei; Lu, Huili; Zhu, Jianwei

    2017-07-01

    It has been documented that the purification of inclusion bodies from Escherichia coli by size exclusion chromatography (SEC) may benefit subsequent refolding and recovery of recombinant proteins. However, loading volume and the high cost of the column limits its application in large-scale manufacturing of biopharmaceutical proteins. We report a novel process using polyethylene glycol (PEG) precipitation under denaturing conditions to replace SEC for rapid purification of inclusion bodies containing recombinant therapeutic proteins. Using recombinant human interleukin 15 (rhIL-15) as an example, inclusion bodies of rhIL-15 were solubilized in 7 M guanidine hydrochloride, and rhIL-15 was precipitated by the addition of PEG 6000. A final concentration of 5% (w/v) PEG 6000 was found to be optimal to precipitate target proteins and enhance recovery and purity. Compared to the previously reported S-200 size exclusion purification method, PEG precipitation was easier to scale up and achieved the same protein yields and quality of the product. PEG precipitation also reduced manufacturing time by about 50 and 95% of material costs. After refolding and further purification, the rhIL-15 product was highly pure and demonstrated a comparable bioactivity with a rhIL-15 reference standard. Our studies demonstrated that PEG precipitation of inclusion bodies under denaturing conditions holds significant potential as a manufacturing process for biopharmaceuticals from E. coli protein expression systems.

  14. Development, optimization, and in vitro characterization of dasatinib-loaded PEG functionalized chitosan capped gold nanoparticles using Box-Behnken experimental design.

    Science.gov (United States)

    Adena, Sandeep Kumar Reddy; Upadhyay, Mansi; Vardhan, Harsh; Mishra, Brahmeshwar

    2018-03-01

    The purpose of this research study was to develop, optimize, and characterize dasatinib loaded polyethylene glycol (PEG) stabilized chitosan capped gold nanoparticles (DSB-PEG-Ch-GNPs). Gold (III) chloride hydrate was reduced with chitosan and the resulting nanoparticles were coated with thiol-terminated PEG and loaded with dasatinib (DSB). Plackett-Burman design (PBD) followed by Box-Behnken experimental design (BBD) were employed to optimize the process parameters. Polynomial equations, contour, and 3D response surface plots were generated to relate the factors and responses. The optimized DSB-PEG-Ch-GNPs were characterized by FTIR, XRD, HR-SEM, EDX, TEM, SAED, AFM, DLS, and ZP. The results of the optimized DSB-PEG-Ch-GNPs showed particle size (PS) of 24.39 ± 1.82 nm, apparent drug content (ADC) of 72.06 ± 0.86%, and zeta potential (ZP) of -13.91 ± 1.21 mV. The responses observed and the predicted values of the optimized process were found to be close. The shape and surface morphology studies showed that the resulting DSB-PEG-Ch-GNPs were spherical and smooth. The stability and in vitro drug release studies confirmed that the optimized formulation was stable at different conditions of storage and exhibited a sustained drug release of the drug of up to 76% in 48 h and followed Korsmeyer-Peppas release kinetic model. A process for preparing gold nanoparticles using chitosan, anchoring PEG to the particle surface, and entrapping dasatinib in the chitosan-PEG surface corona was optimized.

  15. Associations between methylation of paternally expressed gene 3 (PEG3, cervical intraepithelial neoplasia and invasive cervical cancer.

    Directory of Open Access Journals (Sweden)

    Monica D Nye

    Full Text Available Cytology-based screening for invasive cervical cancer (ICC lacks sensitivity and specificity to discriminate between cervical intraepithelial neoplasia (CIN likely to persist or progress from cases likely to resolve. Genome-wide approaches have been used to identify DNA methylation marks associated with CIN persistence or progression. However, associations between DNA methylation marks and CIN or ICC remain weak and inconsistent. Between 2008-2009, we conducted a hospital-based, case-control study among 213 Tanzania women with CIN 1/2/3 or ICC. We collected questionnaire data, biopsies, peripheral blood, cervical scrapes, Human papillomavirus (HPV and HIV-1 infection status. We assessed PEG3 methylation status by bisulfite pyrosequencing. Multinomial logistic regression was used to estimate odds ratios (OR and confidence intervals (CI 95% for associations between PEG3 methylation status and CIN or ICC. After adjusting for age, gravidity, hormonal contraceptive use and HPV infection, a 5% increase in PEG3 DNA methylation was associated with increased risk for ICC (OR = 1.6; 95% CI 1.2-2.1. HPV infection was associated with a higher risk of CIN1-3 (OR = 15.7; 95% CI 5.7-48.6 and ICC (OR = 29.5, 95% CI 6.3-38.4. Infection with high risk HPV was correlated with mean PEG3 differentially methylated regions (DMRs methylation (r = 0.34 p<0.0001, while the correlation with low risk HPV infection was weaker (r = 0.16 p = 0.047. Although small sample size limits inference, these data support that PEG3 methylation status has potential as a molecular target for inclusion in CIN screening to improve prediction of progression. Impact statement: We present the first evidence that aberrant methylation of the PEG3 DMR is an important co-factor in the development of Invasive cervical carcinoma (ICC, especially among women infected with high risk HPV. Our results show that a five percent increase in DNA methylation of PEG3 is associated with

  16. SS-mPEG chemical modification of recombinant phospholipase C for enhanced thermal stability and catalytic efficiency.

    Science.gov (United States)

    Fang, Xian; Wang, Xueting; Li, Guiling; Zeng, Jun; Li, Jian; Liu, Jingwen

    2018-05-01

    PEGylation is one of the most promising and extensively studied strategies for improving the properties of proteins as well as enzymic physical and thermal stability. Phospholipase C, hydrolyzing the phospholipids offers tremendous applications in diverse fields. However, the poor thermal stability and higher cost of production have restricted its industrial application. This study focused on improving the stabilization of recombinant PLC by chemical modification with methoxypolyethylene glycol-Succinimidyl Succinate (SS-mPEG, MW 5000). PLC gene from isolate Bacillus cereus HSL3 was fused with SUMO, a novel small ubiquitin-related modifier expression vector and over expressed in Escherichia coli. The soluble fraction of SUMO-PLC reached 80% of the total recombinant protein. The enzyme exhibited maximum catalytic activity at 80 °C and was relatively thermostable at 40-70 °C. It showed extensive substrate specificity pattern and marked activity toward phosphatidylcholine, which made it a typical non-specific PLC for industrial purpose. SS-mPEG-PLC complex exhibited an enhanced thermal stability at 70-80 °C and the catalytic efficiency (K cat /K m ) had increased by 3.03 folds compared with free PLC. CD spectrum of SS-mPEG-PLC indicated a possible enzyme aggregation after chemical modification, which contributed to the higher thermostability of SS-mPEG-PLC. The increase of antiparallel β sheets in secondary structure also made it more stable than parallel β sheets. The presence of SS-mPEG chains on the enzyme molecule surface somewhat changed the binding rate of the substrates, leading to a significant improvement in catalytic efficiency. This study provided an insight into the addition of SS-mPEG for enhancing the industrial applications of phospholipase C at higher temperature. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Development of PLGA–PEG encapsulated miltefosine based drug delivery system against visceral leishmaniasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rishikesh; Sahoo, Ganesh Chandra [Biomedical and Nanomedicine Department, Rajendra Memorial Research Institute Medical Science (ICMR) (India); Pandey, Krishna; Das, V.N.R.; Topno, Roshan K. [Clinical Medicine Department, Rajendra Memorial Research Institute Medical Science (ICMR) (India); Ansari, Md Yousuf [Pharmacoinformatics Department, National Institute Pharmaceutica Research and Education Industrial Area, Hajipur (India); Rana, Sindhuprava [Biomedical and Nanomedicine Department, Rajendra Memorial Research Institute Medical Science (ICMR) (India); Das, Pradeep [Molecular Biology Department, Rajendra Memorial Research Institute Medical Science (ICMR) (India)

    2016-02-01

    Targeted drug delivery systems are ideal technology to increase the maximum mechanism of action with smaller dose, we have developed miltefosine encapsulated PLGA–PEG nanoparticles (PPEM) to target macrophage of infected tissues against Leishmania donovani. The structural characterization of PLGA–PEG by transmission electron microscopy (TEM) has shown a size range of 10 to 15 nm. Synthesis and drug encapsulation confirmed by dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR) and confirmed NP encapsulation. The dose of nano encapsulated miltefosine decreased by fifty percent as compared to that of a conventional miltefosine and Amphoterecin B. The inhibition of amastigotes in the splenic tissue with nano encapsulated miltefosine (23.21 ± 23) was significantly more than the conventional miltefosine (89.22 ± 52.7) and Amphoterecin B (94.12 ± 55.1). This study signifies that there is an increased contact surface area of the nano encapsulated drug and significant reduction in size, improved the efficacy in both in vitro and in vivo study than that of the conventional miltefosine, Amphoterecin B. - Graphical abstract: The analyses of detailed structure characterized by TEM and DLS confirmed the nano-size of the particle 10–20 nm and FTIR confirmed for antileishmanial drug encapsulation in to PLGA–PEG. The dose of miltefosine is decreased by fifty percent as the IC50 value is decreased from 0.2 to 0.1 μg. Further inhibitions of amastigotes in the splenic tissue with these nanoparticles are significantly more than the conventional miltefosine and PLGA–PEG encapsulated Amphoterecin B (23.21 ± 23/89.09 ± 52.7/92.12 ± 55.1). - Highlights: • Synthesis of PLGA-PEG encapsulated miltefosine nanoparticles has been done. • An IC50 value of PPEM (0.1 ug/ml), miltefosine (0.2 μg/ml) and AmpB (1 μg/ml) were observed two fold better efficacies. • Inhibition of amastigotes of PPEM (23.21 ± 23) was significantly more than

  18. Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity

    International Nuclear Information System (INIS)

    Esfandyari-Manesh, Mehdi; Darvishi, Behrad; Ishkuh, Fatemeh Azizi; Shahmoradi, Elnaz; Mohammadi, Ali; Javanbakht, Mehran; Dinarvand, Rassoul; Atyabi, Fatemeh

    2016-01-01

    The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a controlled release of PTX, because of the presence of imprinted sites in the polymeric structure, which makes it is suitable for sustained drug delivery. The drug release from polymeric nanoparticles was indeed higher at acidic pH. The molecular structure of MIP-PEG-FA was confirmed by Hydrogen-Nuclear Magnetic Resonance (H NMR), Fourier Transform InfraRed (FT-IR), and Attenuated Total Reflection (ATR) spectroscopy, and their thermal behaviors by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Scanning Electron Microscopy (SEM) and Photon Correlation Spectroscopy (PCS) results showed that nanoparticles have a smooth surface and spherical shape with an average size of 181 nm. MIP-PEG-FA nanoparticles showed a greater amount of intracellular uptake in folate receptor-positive cancer cells (MDA-MB-231 cells) in comparison with the non-folate nanoparticles and free PTX, with half maximal inhibitory concentrations (IC_5_0) of 4.9 ± 0.9, 7.4 ± 0.5 and 32.8 ± 3.8 nM, respectively. These results suggest that MIP-PEG-FA nanoparticles could be a potentially useful drug carrier for targeting drug delivery to cancer cells. - Highlights: • MIP-PEG-FA was synthesized as a controlled release carrier for targeting delivery to cancerous cells. • Nanoparticles

  19. Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Esfandyari-Manesh, Mehdi [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Darvishi, Behrad [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ishkuh, Fatemeh Azizi [Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shahmoradi, Elnaz [Department of Chemical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mohammadi, Ali [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Javanbakht, Mehran [Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Dinarvand, Rassoul [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Atyabi, Fatemeh, E-mail: atyabifa@tums.ac.ir [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-05-01

    The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a controlled release of PTX, because of the presence of imprinted sites in the polymeric structure, which makes it is suitable for sustained drug delivery. The drug release from polymeric nanoparticles was indeed higher at acidic pH. The molecular structure of MIP-PEG-FA was confirmed by Hydrogen-Nuclear Magnetic Resonance (H NMR), Fourier Transform InfraRed (FT-IR), and Attenuated Total Reflection (ATR) spectroscopy, and their thermal behaviors by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Scanning Electron Microscopy (SEM) and Photon Correlation Spectroscopy (PCS) results showed that nanoparticles have a smooth surface and spherical shape with an average size of 181 nm. MIP-PEG-FA nanoparticles showed a greater amount of intracellular uptake in folate receptor-positive cancer cells (MDA-MB-231 cells) in comparison with the non-folate nanoparticles and free PTX, with half maximal inhibitory concentrations (IC{sub 50}) of 4.9 ± 0.9, 7.4 ± 0.5 and 32.8 ± 3.8 nM, respectively. These results suggest that MIP-PEG-FA nanoparticles could be a potentially useful drug carrier for targeting drug delivery to cancer cells. - Highlights: • MIP-PEG-FA was synthesized as a controlled release carrier for targeting delivery to cancerous cells. • Nanoparticles

  20. Efficient Self-Assembly of mPEG End-Capped Porous Silica as a Redox-Sensitive Nanocarrier for Controlled Doxorubicin Delivery

    Directory of Open Access Journals (Sweden)

    Anh Khoa Nguyen

    2018-01-01

    Full Text Available Porous nanosilica (PNS has been regarded as a promising candidate for controlled delivery of anticancer drugs. Unmodified PNS-based nanocarriers, however, showed a burst release of encapsulated drugs, which may limit their clinical uses. In this report, PNS was surface conjugated with adamantylamine (ADA via disulfide bridges (-SS-, PNS-SS-ADA, which was further modified with cyclodextrin-poly(ethylene glycol methyl ether conjugate (CD-mPEG to form a core@shell structure PNS-SS-ADA@CD-mPEG for redox triggered delivery of doxorubicin (DOX, DOX/PNS-SS-ADA@CD-mPEG. The prepared PNS-SS-ADA@CD-mPEG nanoparticles were spherical in shape with an average diameter of 55.5 ± 3.05 nm, a little larger than their parentally PNS nanocarriers, at 49.6 ± 2.56 nm. In addition, these nanoparticles possessed high drug loading capacity, at 79.2 ± 3.2%, for controlled release. The release of DOX from DOX/PNS-SS-ADA@CD-mPEG nanoparticles was controlled and prolonged up to 120 h in PBS medium (pH 7.4, compared to less than 40 h under reducing condition of 5 mM DTT. Notably, the PNS-SS-ADA@CD-mPEG was a biocompatible nanocarrier, and the toxicity of DOX was dramatically reduced after loading drugs into the porous core. This redox-sensitive PNS-SS-ADA@CD-mPEG nanoparticle could be considered a potential candidate with high drug loading capacity and a lower risk of systemic toxicity.

  1. Noncovalent PEGylation: different effects of dansyl-, L-tryptophan-, phenylbutylamino-, benzyl- and cholesteryl-PEGs on the aggregation of salmon calcitonin and lysozyme.

    Science.gov (United States)

    Mueller, Claudia; Capelle, Martinus A H; Seyrek, Emek; Martel, Sophie; Carrupt, Pierre-Alain; Arvinte, Tudor; Borchard, Gerrit

    2012-06-01

    Protein aggregation is a major instability that can occur during all stages of protein drug production and development. Protein aggregates may compromise the safety and efficacy of the final protein formulation. In this paper, various new excipients [phenylbutylamino-, benzyl-, and cholesteryl-polyethylene glycols (PEGs)] and their use for the reduction of aggregation of salmon calcitonin (sCT) and hen egg-white lysozyme (HEWL) by noncovalent PEGylation are presented. The ability to suppress aggregation of sCT in various buffer systems at a 1:1 molar ratio was assessed by following changes in protein conformation and aggregation state over time. The results are compared with that of dansyl- and L-tryptophan (Trp)-PEGs described in earlier publications. Furthermore, the influence of the different PEG-based excipients on the aggregation of HEWL was measured. HEWL aggregation was completely suppressed in the presence of cholesteryl-PEGs (2 and 5 kDa), whereas deterioration was observed using benzyl-methoxy polyethylene glycols (mPEGs; 2 and 5 kDa). Phenylbutylamino- and Trp-mPEG (2 kDa), as well as dansyl-PEGs of different molecular weight prolonged the lag phase of aggregation and reduced the aggregation velocity of HEWL. Copyright © 2012 Wiley Periodicals, Inc.

  2. II Peg: Spectroscopic Evidence for Multiple Starspot Temperatures

    Science.gov (United States)

    O'Neal, Douglas; Saar, Steven H.; Neff, James E. Neff

    We present spectroscopic evidence for multiple spot temperatures on the RS CVn star II Pegasi (HD 224085). We fit the strengths of the 7055 AAg and 8860 AAg TiO absorption bands in the spectrum of an active star using weighted sums of comparison spectra: the spectrum of an inactive K star to represent the non-spotted photosphere and the spectrum of an M star to represent the spots. We can thus independently measure starspot filling factor (fspot) and temperature (tspot). During 3/4 of a rotation of II Peg in Sept.-Oct. 1996, we measure fspot approximately constant at 55+/-5%. However, tspot varies from 3350 K to 3500 K. Since our method yields one derived tspot integrated over the visible hemisphere of the star, we present the results of simple models of a star with two distinct spot temperatures and compute the tspot we would derive in those cases. The changing tspot correlates with emission strengths of Hα and the Ca 2 infrared triplet, in the sense that cooler \\tspot accompanies weaker emission. We explore the consequences of these results for the physical properties of the spots on II Peg and for stellar surface structure in general.

  3. Structural and electrochemical studies of PPy/PEG-LiFePO4 cathode material for Li-ion batteries

    International Nuclear Information System (INIS)

    Fedorkova, Andrea; Nacher-Alejos, Ana; Gomez-Romero, Pedro; Orinakova, Renata; Kaniansky, Dusan

    2010-01-01

    A simple chemical oxidative polymerization of pyrrole (Py) directly onto the surface of LiFePO 4 particles was applied to the synthesis of polypyrrole-LiFePO 4 (PPy-LiFePO 4 ) powder. The LiFePO 4 sample without carbon coating was synthesized by a solvothermal method. The polyethylene glycol (PEG) was used as additive during Py polymerization for increasing the PPy-LiFePO 4 conductivity. Properties of resulting LiFePO 4 , PPy-LiFePO 4 and PPy/PEG-LiFePO 4 samples were characterized by XRD, SEM, TGA and galvanostatic charge-discharge measurements. These methods confirmed the presence of polypyrrole on LiFePO 4 particles and its homogeneous distribution in the resulting powder material. The PPy/PEG-LiFePO 4 composites show higher discharge capacity than pure LiFePO 4 , as PPy/PEG network improves the electron conductivity. It presents specific discharge capacity of 153 mAh/g at C/5 rate.

  4. Two-week aerosol inhalation study on polyethylene glycol (PEG) 3350 in F-344 rats.

    Science.gov (United States)

    Klonne, D R; Dodd, D E; Losco, P E; Troup, C M; Tyler, T R

    1989-03-01

    PEGs in the 3000 to 4000 MW range are used in many pharmaceutical and cosmetic applications; they produce little ocular or dermal irritation and have extremely low acute and subchronic toxicity by oral and dermal routes of administration. However, little information exists on the potential of aerosols of these materials to produce adverse health effects. F-344 rats were exposed to aerosols of PEG 3350 (20% w:w in water) at 0, 109, 567, or 1008 (highest attainable) mg/m3 for 6 hr/d, 5 d/wk for 2 wk. No exposure-related toxicity was found with regard to clinical signs, ophthalmology, serum chemistry, urinalysis, or gross pathology. Exposure-related effects included: a 50% increase in the neutrophil count (males only) at 1008 mg/m3; decreased body weight gain (16%) for both the 567 and 1008 mg/m3 groups (males only); absolute lung weights of both sexes were increased 10 and 18% for the 567 and 1008 mg/m3 groups, respectively. A slight increase in the number of macrophages in the alveoli was the only change observed histologically in all PEG 3350-exposed groups. Therefore, inhalation of aerosols of PEG 3350 at concentrations up to 1008 mg/m3 produced relatively little toxicity in rats, the lung was the target organ, and the no-observable-effect-level was between 109 to 567 mg/m3.

  5. Micropatterning of a nanoporous alumina membrane with poly(ethylene glycol) hydrogel to create cellular micropatterns on nanotopographic substrates.

    Science.gov (United States)

    Lee, Hyun Jong; Kim, Dae Nyun; Park, Saemi; Lee, Yeol; Koh, Won-Gun

    2011-03-01

    In this paper, we describe a simple method for fabricating micropatterned nanoporous substrates that are capable of controlling the spatial positioning of mammalian cells. Micropatterned substrates were prepared by fabricating poly(ethylene glycol) (PEG) hydrogel microstructures on alumina membranes with 200 nm nanopores using photolithography. Because hydrogel precursor solution could infiltrate and become crosslinked within the nanopores, the resultant hydrogel micropatterns were firmly anchored on the substrate without the use of adhesion-promoting monolayers, thereby allow tailoring of the surface properties of unpatterned nanoporous areas. For mammalian cell patterning, arrays of microwells of different dimensions were fabricated. These microwells were composed of hydrophilic PEG hydrogel walls surrounding nanoporous bottoms that were modified with cell-adhesive Arg-Gly-Asp (RGD) peptides. Because the PEG hydrogel was non-adhesive towards proteins and cells, cells adhered selectively and remained viable within the RGD-modified nanoporous regions, thereby creating cellular micropatterns. Although the morphology of cell clusters and the number of cells inside one microwell were dependent on the lateral dimension of the microwells, adhered cells that were in direct contact with nanopores were able to penetrate into the nanopores by small extensions (filopodia) for all the different sizes of microwells evaluated. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. Enhanced thermal properties of novel shape-stabilized PEG composite phase change materials with radial mesoporous silica sphere for thermal energy storage.

    Science.gov (United States)

    Min, Xin; Fang, Minghao; Huang, Zhaohui; Liu, Yan'gai; Huang, Yaoting; Wen, Ruilong; Qian, Tingting; Wu, Xiaowen

    2015-08-11

    Radial mesoporous silica (RMS) sphere was tailor-made for further applications in producing shape-stabilized composite phase change materials (ss-CPCMs) through a facile self-assembly process using CTAB as the main template and TEOS as SiO2 precursor. Novel ss-CPCMs composed of polyethylene glycol (PEG) and RMS were prepared through vacuum impregnating method. Various techniques were employed to characterize the structural and thermal properties of the ss-CPCMs. The DSC results indicated that the PEG/RMS ss-CPCM was a promising candidate for building thermal energy storage applications due to its large latent heat, suitable phase change temperature, good thermal reliability, as well as the excellent chemical compatibility and thermal stability. Importantly, the possible formation mechanisms of both RMS sphere and PEG/RMS composite have also been proposed. The results also indicated that the properties of the PEG/RMS ss-CPCMs are influenced by the adsorption limitation of the PEG molecule from RMS sphere with mesoporous structure and the effect of RMS, as the impurities, on the perfect crystallization of PEG.

  7. Pegademase bovine (PEG-ADA for the treatment of infants and children with severe combined immunodeficiency (SCID

    Directory of Open Access Journals (Sweden)

    Claire Booth

    2009-06-01

    Full Text Available Claire Booth1,2, H Bobby Gaspar1,21Centre for Immunodeficiency, Molecular Immunology Unit, UCL Institute of Child Health, London, UK; 2Dept of Clinical Immunology, Great Ormond Street Hospital NHS Trust, London, UKAbstract: Adenosine deaminase deficiency (ADA is a rare, inherited disorder of purine metabolism characterized by immunodeficiency, failure to thrive and metabolic abnormalities. A lack of the enzyme ADA allows accumulation of toxic metabolites causing defects of both cell mediated and humoral immunity leading to ADA severe combined immune deficiency (SCID, a condition that can be fatal in early infancy if left untreated. Hematopoietic stem cell transplant is curative but is dependent on a good donor match. Other therapeutic options include enzyme replacement therapy (ERT with pegademase bovine (PEG-ADA and more recently gene therapy. PEG-ADA has been used in over 150 patients worldwide and has allowed stabilization of patients awaiting more definitive treatment with hematopoietic stem cell transplant. It affords both metabolic detoxification and protective immune function with patients remaining clinically well, but immune reconstitution is often suboptimal and may not be long lived. We discuss the pharmacokinetics, immune reconstitution, effects on systemic disease and side effects of treatment with PEG-ADA. We also review the long-term outcome of patients receiving ERT and discuss the role of PEG-ADA in the management of infants and children with ADA-SCID, alongside other therapeutic options.Keywords: adenosine deaminase deficiency, PEG-ADA, enzyme replacement therapy, severe combined immune deficiency (SCID

  8. PEGylation of Phytantriol-Based Lyotropic Liquid Crystalline Particles-The Effect of Lipid Composition, PEG Chain Length, and Temperature on the Internal Nanostructure

    DEFF Research Database (Denmark)

    Nilsson, Christa; Ostergaard, Jesper; Larsen, Susan Weng

    2014-01-01

    of these lipidic nonlamellar liquid crystalline particles by using DSPE-mPEGs with three different block lengths of the hydrophilic PEG segment. The effects of lipid composition, PEG chain length, and temperature on the morphology and internal nanostructure of these self-assembled lipidic aqueous dispersions based...

  9. Mussel-inspired histidine-based transient network metal coordination hydrogels

    Science.gov (United States)

    Fullenkamp, Dominic E.; He, Lihong; Barrett, Devin G.; Burghardt, Wesley R.; Messersmith, Phillip B.

    2013-01-01

    Transient network hydrogels cross-linked through histidine-divalent cation coordination bonds were studied by conventional rheologic methods using histidine-modified star poly(ethylene glycol) (PEG) polymers. These materials were inspired by the mussel, which is thought to use histidine-metal coordination bonds to impart self-healing properties in the mussel byssal thread. Hydrogel viscoelastic mechanical properties were studied as a function of metal, pH, concentration, and ionic strength. The equilibrium metal-binding constants were determined by dilute solution potentiometric titration of monofunctional histidine-modified methoxy-PEG and were found to be consistent with binding constants of small molecule analogs previously studied. pH-dependent speciation curves were then calculated using the equilibrium constants determined by potentiometric titration, providing insight into the pH dependence of histidine-metal ion coordination and guiding the design of metal coordination hydrogels. Gel relaxation dynamics were found to be uncorrelated with the equilibrium constants measured, but were correlated to the expected coordination bond dissociation rate constants. PMID:23441102

  10. Progesterone PLGA/mPEG-PLGA Hybrid Nanoparticle Sustained-Release System by Intramuscular Injection.

    Science.gov (United States)

    Xie, Bin; Liu, Yang; Guo, Yuting; Zhang, Enbo; Pu, Chenguang; He, Haibing; Yin, Tian; Tang, Xing

    2018-02-14

    To prepare sustained-release PLGA/mPEG-PLGA hybrid nanoparticles of progesterone (PRG), and evaluate the descending required administration dosage in vivo. PRG hybrid nanoparticles (PRG H-NPs) based on PLGA/mPEG-PLGA were compared with PRG nanoparticles (PRG-NPs) of pure PLGA as the matrix and PRG-oil solutions. Nanoparticles (NPs) were formed by the method of nanoemulsion, and the pharmacokinetics of the sustained-release PRG H-NPs in male Sprague dawley (SD) rats were investigated. The rats were randomly divided into four groups, each group received: single dose of PRG H-NPs (14.58 mg/kg, i.m.) and PRG-NPs (14.58 mg/kg, i.m.), repeated dosing for 7 days of PRG-oil (2.08 mg/kg, i.m.) solution (Oil-L) and a higher dosage of PRG-oil (6.24 mg/kg, i.m.) solution (Oil-H), respectively. In the pharmacokinetic test, the PRG H-NPs exhibited a comparatively good sustained-release effect against the PRG-NPs without mPEG-PLGA and PRG-oil solution. The pharmacokinetic parameters of the PRG H-NPs, PRG-NPs, Oil-L and Oil-H were AUC 0-t (ng·h·mL -1 ) 8762.1, 1546.1, 1914.5, and 12,138.9, t 1/2 (h)52.7, 44.1, 8.4 and 44.6 respectively. Owing to the modification of PEG, PRG H-NPs can act as safe delivery platforms for sustained-release of drugs with a lower dosage required.

  11. Ring and peg electrodes for minimally-Invasive and long-term sub-scalp EEG recordings.

    Science.gov (United States)

    Benovitski, Y B; Lai, A; McGowan, C C; Burns, O; Maxim, V; Nayagam, D A X; Millard, R; Rathbone, G D; le Chevoir, M A; Williams, R A; Grayden, D B; May, C N; Murphy, M; D'Souza, W J; Cook, M J; Williams, C E

    2017-09-01

    Minimally-invasive approaches are needed for long-term reliable Electroencephalography (EEG) recordings to assist with epilepsy diagnosis, investigation and more naturalistic monitoring. This study compared three methods for long-term implantation of sub-scalp EEG electrodes. Three types of electrodes (disk, ring, and peg) were fabricated from biocompatible materials and implanted under the scalp in five ambulatory ewes for 3months. Disk electrodes were inserted into sub-pericranial pockets. Ring electrodes were tunneled under the scalp. Peg electrodes were inserted into the skull, close to the dura. EEG was continuously monitored wirelessly. High resolution CT imaging, histopathology, and impedance measurements were used to assess the status of the electrodes at the end of the study. EEG amplitude was larger in the peg compared with the disk and ring electrodes (pEEG, mechanical stability, and lower chewing artifact. Whereas, ring electrode arrays tunneled under the scalp enable minimal surgical techniques to be used for implantation and removal. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Blends of PHB/PEG: obtention of matrices for use as controlled drug release systems

    International Nuclear Information System (INIS)

    Catoni, S.E.M.; Gomes, C.A.T.; Trindade, K.N.S.; Schneider, A.L.S.; Pezzin, A.P.T.; Soldi, V.

    2010-01-01

    Different materials have been used in the development of micro-and nanostructured systems for drug release. In general, poly(3-hydroxybutyrate) (PHB) matrixes have high crystallinity degree, justifying its slow degradation. This feature makes the attack of enzymes more difficult. Thus, the surface modification with hydrophilic polymers such as poly(ethylene glycol) (PEG) has been investigated in order to obtain particles which are not recognized and captured by phagocytic cells after in vivo administration, staying for a longer in the systemic circulation. In this work, PHB/PEG films were prepared by casting in different proportions and characterized by XRD, DSC, SEM, GPC and TGA. The films presented high crystallinity degree and showed uniformity, except the 50/50 composition which showed the presence of two phases. The results revealed that increasing percentage of PEG, the Tm of PHB was decreased, the thermal stability was dramatically decreased and molecular weight of the samples was lower. (author)

  13. Antifouling activities of β-cyclodextrin stabilized peg based silver nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Punitha, N., E-mail: punithasan@gmail.com [Department of Physics, St. Joseph’s College of Engineering, Chennai 600119 (India); Saravanan, P. [Department of Chemistry, St. Joseph’s College of Engineering, Chennai 600119 (India); Mohan, R. [Department of Physics, Surya College of Engineering and Technology, Villupuram (India); Ramesh, P.S. [Department of Physics (DDE), Annamalai University, Annamalai Nagar 608002 (India)

    2017-01-15

    Highlights: • Simple, novel and cost effective. • Functionalized Ag nanocomposites exhibit enhanced biological activity. • The SNCs were crystalline nature and shows good stability. - Abstract: Self-polishing polymer composites which release metal biocide in a controlled rate have been widely used in the design of antimicrobial agents and antifouling coatings. The present work focuses on the environmental friendly green synthesis of PEG based SNCs and their application to biocidal activity including marine biofouling. Biocompatible polymer β-CD and adhesive resistance polymer PEG were used to functionalize the SNPs and the as synthesized SNCs exhibit excellent micro fouling activities. The structural and optical properties were confirmed by XRD and UV–visible techniques respectively. The particle surface and cross sectional characteristics were examined by SEM-EDS, HR-TEM, AFM and FTIR. The surface potential was evaluated using ZP analysis and assessment of antibiofouling property was investigated using static immersion method.

  14. Antifouling activities of β-cyclodextrin stabilized peg based silver nanocomposites

    International Nuclear Information System (INIS)

    Punitha, N.; Saravanan, P.; Mohan, R.; Ramesh, P.S.

    2017-01-01

    Highlights: • Simple, novel and cost effective. • Functionalized Ag nanocomposites exhibit enhanced biological activity. • The SNCs were crystalline nature and shows good stability. - Abstract: Self-polishing polymer composites which release metal biocide in a controlled rate have been widely used in the design of antimicrobial agents and antifouling coatings. The present work focuses on the environmental friendly green synthesis of PEG based SNCs and their application to biocidal activity including marine biofouling. Biocompatible polymer β-CD and adhesive resistance polymer PEG were used to functionalize the SNPs and the as synthesized SNCs exhibit excellent micro fouling activities. The structural and optical properties were confirmed by XRD and UV–visible techniques respectively. The particle surface and cross sectional characteristics were examined by SEM-EDS, HR-TEM, AFM and FTIR. The surface potential was evaluated using ZP analysis and assessment of antibiofouling property was investigated using static immersion method.

  15. Effective mRNA Inhibition in PANC-1 Cells in Vitro Mediated via an mPEG-SeSe-PEI Delivery System.

    Science.gov (United States)

    Zhang, Yuefeng; Yang, Bin; Liu, Yajie; Qin, Wenjie; Li, Chao; Wang, Lantian; Zheng, Wen; Wu, Yulian

    2016-05-01

    RNA interference (RNAi)-mediated gene therapy is a promising approach to cure various diseases. However, developing an effective, safe, specific RNAi delivery system remains a major challenge. In this study, a novel redox-responsive polyetherimide (PEI)-based nanovector, mPEG-SeSe-PEI, was developed and its efficacy evaluated. We prepared three mPEG-SeSe-PEI vector candidates for small interfering glyceraldehyde-3-phosphate dehydrogenase (siGADPH) and determined their physiochemical properties and transfection efficiency using flow cytometry and PEG11.6-SeSe-PEI polymer. We investigated the silencing efficacy of GADPH mRNA expression in PANC-1 cells and observed that PEG11.6-SeSe-PEI/siGADPH (N/P ratio=10) polyplexes possessed the appropriate size and zeta-potential and exhibited excellent in vitro gene silencing effects with the least cytotoxicity in PANC-1 cells. In conclusion, we present PEG11.6-SeSe-PEI as a potential therapeutic gene delivery system for small interfering RNA (siRNA).

  16. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light

    Science.gov (United States)

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P.; Lee, Jae Young

    2016-07-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation via a mixed-mode reaction with a small increase in temperature (~5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications.Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation

  17. Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Vanesa; Conde, Joao; Hernandez, Yulan [Universidad de Zaragoza, Instituto de Nanociencia de Aragon (Spain); Baptista, Pedro V. [Universidade Nova de Lisboa, Departamento de Ciencias da Vida, Faculdade de Ciencias e Tecnologia, Centro de Investigacao em Genetica Molecular Humana (Portugal); Ibarra, M. R.; Fuente, Jesus M. de la, E-mail: jmfuente@unizar.es [Universidad de Zaragoza, Instituto de Nanociencia de Aragon (Spain)

    2012-06-15

    The surface chemistry of gold nanoparticles (AuNPs) plays a critical role in the self-assembly of thiolated molecules and in retaining the biological function of the conjugated biomolecules. According to the well-established gold-thiol interaction the undefined ionic species on citrate-reduced gold nanoparticle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such derivatives in the functionalization of several types of biomolecules, such as PEGs, peptides or nucleic acids, has become a significant challenge. Here, an approach to attach specific biomolecules to the AuNPs ({approx}14 nm) surface is presented together with a study of their effect in the functionalization with other specific derivatives. The effect of biofunctional spacers such as thiolated poly(ethylene glycol) (PEG) chains and a positive peptide, TAT, in dsRNA loading on AuNPs is reported. Based on the obtained data, we hypothesize that loading of oligonucleotides onto the AuNP surface may be controlled by ionic and weak interactions positioning the entry of the oligo through the PEG layer. We demonstrate that there is a synergistic effect of the TAT peptide and PEG chains with specific functional groups on the enhancement of dsRNA loading onto AuNPs.

  18. Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles

    International Nuclear Information System (INIS)

    Sanz, Vanesa; Conde, João; Hernández, Yulán; Baptista, Pedro V.; Ibarra, M. R.; Fuente, Jesús M. de la

    2012-01-01

    The surface chemistry of gold nanoparticles (AuNPs) plays a critical role in the self-assembly of thiolated molecules and in retaining the biological function of the conjugated biomolecules. According to the well-established gold–thiol interaction the undefined ionic species on citrate-reduced gold nanoparticle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such derivatives in the functionalization of several types of biomolecules, such as PEGs, peptides or nucleic acids, has become a significant challenge. Here, an approach to attach specific biomolecules to the AuNPs (∼14 nm) surface is presented together with a study of their effect in the functionalization with other specific derivatives. The effect of biofunctional spacers such as thiolated poly(ethylene glycol) (PEG) chains and a positive peptide, TAT, in dsRNA loading on AuNPs is reported. Based on the obtained data, we hypothesize that loading of oligonucleotides onto the AuNP surface may be controlled by ionic and weak interactions positioning the entry of the oligo through the PEG layer. We demonstrate that there is a synergistic effect of the TAT peptide and PEG chains with specific functional groups on the enhancement of dsRNA loading onto AuNPs.

  19. Polymer-lipid-PEG hybrid nanoparticles as photosensitizer carrier for photodynamic therapy.

    Science.gov (United States)

    Pramual, Sasivimon; Lirdprapamongkol, Kriengsak; Svasti, Jisnuson; Bergkvist, Magnus; Jouan-Hureaux, Valérie; Arnoux, Philippe; Frochot, Céline; Barberi-Heyob, Muriel; Niamsiri, Nuttawee

    2017-08-01

    Polymer-lipid-PEG hybrid nanoparticles were investigated as carriers for the photosensitizer (PS), 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H,23H-porphine (pTHPP) for use in photodynamic therapy (PDT). A self-assembled nanoprecipitation technique was used for preparing two types of core polymers poly(d,l-lactide-co-glycolide) (PLGA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with lipid-PEG as stabilizer. The resulting nanoparticles had an average particle size of 88.5±3.4nm for PLGA and 215.0±6.3nm for PHBV. Both nanoparticles exhibited a core-shell structure under TEM with high zeta potential and loading efficiency. X-ray powder diffraction analysis showed that the encapsulated pTHPP molecules in polymeric nanoparticles no longer had peaks of free pTHPP in the crystalline state. The pTHPP molecules encapsulated inside the polymeric core demonstrated improved photophysical properties in terms of singlet oxygen generation and cellular uptake rate in a FTC-133 human thyroid carcinoma cell line, compared to non-encapsulated pTHPP. The pTHPP-loaded polymer-lipid-PEG nanoparticles showed better in vitro phototoxicity compared to free pTHPP, in both time- and concentration-dependent manners. Overall, this study provides detailed analysis of the photophysical properties of pTHPP molecules when entrapped within either PLGA or PHBV nanoparticle cores, and demonstrates the effectiveness of these systems for delivery of photosensitizers. The two polymeric systems may have different potential benefits, when used with cancer cells. For instance, the pTHPP-loaded PLGA system requires only a short time to show a PDT effect and may be suitable for topical PDT, while the delayed photo-induced cytotoxic effect of the pTHPP-loaded PHBV system may be more suitable for cancer solid tumors. Hence, both pTHPP-encapsulated polymer-lipid-PEG nanoparticles can be considered promising delivery systems for PDT cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Doxorubicin loaded PEG-b-poly(4-vinylbenzylphosphonate) coated magnetic iron oxide nanoparticles for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Hałupka-Bryl, Magdalena, E-mail: magdalenahalupka@op.pl [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Bednarowicz, Magdalena [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Dobosz, Bernadeta; Krzyminiewski, Ryszard [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Zalewski, Tomasz [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Wereszczyńska, Beata [Department of Macromolecular Physics, Adam Mickiewicz University, Poznań (Poland); Nowaczyk, Grzegorz; Jarek, Marcin [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Nagasaki, Yukio [Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Master’s School of Medicinal Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba (Japan); International Centre for Materials Nanoarchitectonics Satellite (WPI-MANA), National Institute For Materials Sciences (NIMS) and University of Tsukuba (Japan)

    2015-06-15

    Due to their unique physical properties, superparamagnetic iron oxide nanoparticles are increasingly used in medical applications. They are very useful carriers for delivering antitumor drugs in targeted cancer treatment. Magnetic nanoparticles with chemiotherapeutic were synthesized by coprecipitation method followed by coating with biocompatible polymer. The aim of this work is to characterize physical and magnetic properties of synthesized nanoparicles. Characterization was carried out using EPR, HRTEM, X-ray diffraction, SQUID and NMR methods. The present findings show that synthesized nanosystem is promising tool for potential magnetic drug delivery. - Highlights: • Synthesized PEG-PIONs/DOX have excellent physical properties. • PEG-PIONs/DOX have a potential to in vivo application. • PEG-PIONs/DOX could be used as drug delivery system as well as contrast agents.

  1. Fabrication of biodegradable PEG-PLA nanospheres for solubility, stabilization, and delivery of curcumin.

    Science.gov (United States)

    Liang, Hongying; Friedman, Joel M; Nacharaju, Parimala

    2017-03-01

    Curcumin is an effective and safe anticancer agent, and also known to induce vasodilation, but its hydrophobicity limits its clinical application. In this study, a simple emulsion method was developed to prepare biodegradable poly (ethylene glycol)-poly (lactic acid) (PEG-PLA) nanospheres to encapsulate curcumin to improve its solubility and stability. The nanoparticle size was around 150 nm with a narrow size distribution. Fluorescence microscopy showed that curcumin encapsulated PEG-PLA nanospheres were taken up rapidly by Hela and MDA-MB-231 cancer cells. This novel nanoparticulate carrier may improve the bioavailability of curcumin without affecting its anticancer properties.

  2. An efficient PEG-400 mediated catalyst free green synthesis of 2 ...

    Indian Academy of Sciences (India)

    aDepartment of Chemistry, Acharya Nagarjuna University, N Nagar, Andhra Pradesh, 522 510 India ... usage of organic solvents and harsh reaction conditions. 2. ... glycol (PEG-400) medium. Entry α-diazoketone. 2-aminothiazole. Time (h).

  3. Preparation, structural analysis and bioactivity of ribonuclease A-albumin conjugate: tetra-conjugation or PEG as the linker.

    Science.gov (United States)

    Li, Chunju; Lin, Qixun; Wang, Jun; Shen, Lijuan; Ma, Guanghui; Su, Zhiguo; Hu, Tao

    2012-12-31

    Ribonuclease A (RNase A) is a therapeutic enzyme with cytotoxic action against tumor cells. Its clinical application is limited by the short half-life and insufficient stability. Conjugation of albumin can overcome the limitation, whereas dramatically decrease the enzymatic activity of RNase A. Here, three strategies were proposed to prepare the RNase A-bovine serum albumin (BSA) conjugates. R-SMCC-B (a conjugate of four RNase A attached with one BSA) and R-PEG-B (a mono-conjugate) were prepared using Sulfo-SMCC (a short bifunctional linker) and mal-PEG-NHS (a bifunctional PEG), respectively. Mal-PEG-NHS and hexadecylamine (HDA) were used to prepare the mono-conjugate, R-HDA-B, where HDA was adopted to bind BSA. The PEG linker can elongate the proximity between RNase A and BSA. In contrast, four RNase A were closely located on BSA in R-SMCC-B. R-SMCC-B showed the lowest K(m) and the highest relative enzymatic activity and k(cat)/K(m) in the three conjugates. Presumably, the tetravalent interaction of RNase A in R-SMCC-B can increase the binding affinity to its substrate. In addition, the slow release of BSA from R-HDA-B may increase the enzymatic activity of R-HDA-B. Our study is expected to provide strategies to develop protein-albumin conjugate with high therapeutic potential. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Influence of Polyethylene Glycol (PEG in CMC-NH4BR Based Polymer Electrolytes: Conductivity and Electrical Study

    Directory of Open Access Journals (Sweden)

    Nur Khalidah Zainuddin

    2017-04-01

    Full Text Available The present work was carried with new type and promising polymer electrolytes system by development of carboxylmethylcellulose (CMC doped NH4Br and plasticized with polyethylene glycol (PEG. The sample was successfullyprepared via solution casting with no separation phase and good mechanical properties. The electrical conductivity andthermal conductivity of CMC-NH4Br-PEG based PEs system have been measured by the electrical impedancespectroscopy method in the temperature range of 303–373 K. The highest ionic conductivity gained is 2.48 x 10-3 Scm-1at ambient temperature for sample contain with 8 wt. % PEG. It can be concluded that the plasticized is accountable forthe conductance and assist to enhancing the ionic conductivity of the CMC-NH4Br-PEG electrolyte system. The addition of PEG to the CMC-based electrolyte can enhance towards the cation mobility which is turn increases ionic conductivity. The conductivity-temperature of plasticized BdPEs system was found obeys the Arrhenius relation where the ionic conductivity increases with temperature and activation energy for the ions hopping of the highest conducting PEs system only required small value to migrate. The electrical studies show a non-Debye behaviour of BdPEs based on the analyzed data using complex permittivity, ε* and complex electrical modulus, M* of the sample at different temperature.

  5. A randomized, controlled, double-blind trial of the adjunct use of Clebopride in polyethylene glycol electrolyte (PEG) solution for colonoscopy preparation.

    Science.gov (United States)

    Abdullah, Murdani; Rani, A Aziz; Fauzi, Achmad; Syam, Ari Fahrial; Makmun, Dadang; Simadibrata, Marcellus; Manan, Chudahman; Harjodisastro, Daldiyono

    2010-01-01

    To study the benefit of Clebopride as an adjuvant in polyethylene glycol electrolyte (PEG) solution for colonoscopy preparation. Eighty one adult patients who underwent colonoscopy examination were recruited in this randomized double blind controlled study. First group received PEG and placebo, whereas second group received PEG and Clebopride. Two litres of PEG was taken at night before colonoscopy. The acceptability and tolerability of bowel preparation were assessed through interview method. The efficacy of bowel preparation was assessed using Aronchick's Criteria. In terms of acceptability, 64 patients (31 patients from placebo group vs 33 patients from Clebopride group) were able to drink two litres of PEG solution. Sixty patients (29 patients from placebo group and 31 patients from Clebopride group) were willing to accept PEG solution for their next bowel preparation. On the term of tolerability, nausea, abdominal distension, and borborygmus were more frequent in the placebo group (34.2% vs 27.9%; 44.7% vs 32.6%; 26.3% vs 4.6% respectively). However, only the difference at the incidence of borborygmus that was statistically significant (pClebopride group and 81.6% of bowel preparation in placebo group were optimal (p = 0.585). The adjunct use of Clebopride in PEG solution for colonoscopy preparations tends to increase the acceptability, tolerability, and efficacy. The presence of borborygmus was significantly lower in the Clebopride group.

  6. Production of bioinspired and rationally designed polymer hydrogels for controlled delivery of therapeutic proteins

    Science.gov (United States)

    Kim, Sung Hye

    Hydrogel systems for controlled delivery therapeutic growth factors have been developed in a wide spectrum of strategies: these systems aim for the release of growth factors via a passive diffusion, electrostatic interaction, degradation of hydrogels, and responsiveness to external stimuli. Heparin, a highly sulfated glycosaminoglycan (GAG), was employed for a targeted delivery system of vascular endothelial growth factor (VEGF) to endothelial cells overexpressing a relevant receptor VEGFR-2. Addition of dimeric VEGF to 4-arm star-shaped poly(ethylene glycol) (PEG) immobilized with low-molecular weight heparin (LMWH) afforded a non-covalently assembled hydrogel via interaction between heparin and VEGF, with storage modulus 10 Pa. The release of VEGF and hydrogel erosion reached maximum 100 % at day 4 in the presence of VEGFR-2 overexpressing pocine aortic endothelial cell (PAE/KDR), while those of 80% were achieved via passive release at day 5 in the presence of PAE cell lacking VEGFR-2 or in the absence of cell, indicating that the release of VEGF was in targeted manner toward cell receptor. The proliferation of PAE/KDR in the presence of [PEG-LMWH/VEGF] hydrogel was greater by ca. 30% at day 4 compared to that of PAE, confirming that the release of VEGF was in response to the cellular demand. The phosphorylation fraction of VEGFR-2 on PAE/KDR was greater in the presence of [PEG-LMWH/VEGF] hydrogel, increasing from 0.568 at day 1 to 0.790 at day 4, whereas it was maintained at 0.230 at day 4 in the presence of [PEG-LMWH] hydrogel. This study has proven that this hydrogel, assembled via bio-inspired non-covalent interaction, liberating VEGFon celluar demand to target cell, eroding upon VEGF release, and triggering endothelial cell proliferation, could be used in multiple applications including targeted delivery and angiogenesis. Heparin has been widely exploited in growth factor delivery systems owing to its ability to bind many growth factors through the flexible

  7. NuLYTELY (PEG 3350, sodium chloride, sodium bicarbonate and potassium chloride for oral solution).

    Science.gov (United States)

    Swartz, M L

    1992-02-01

    NuLYTELY (PEG 3350, Sodium Chloride, Sodium Bicarbonate, and Potassium Chloride for Oral Solution), a product from Braintree Laboratories, Inc. is a modification of GoLYTELY (PEG 3350 and Electrolytes for Oral Solution) that has been found to have the same therapeutic advantages in terms of safety, efficacy, speed and patient acceptance. This product was developed to improve upon the taste of GoLYTELY. NuLYTELY represents an effective alternative for bowel cleansing prior to colonoscopy that may be more acceptable to some patients.

  8. Pegademase bovine (PEG-ADA) for the treatment of infants and children with severe combined immunodeficiency (SCID).

    Science.gov (United States)

    Booth, Claire; Gaspar, H Bobby

    2009-01-01

    Adenosine deaminase deficiency (ADA) is a rare, inherited disorder of purine metabolism characterized by immunodeficiency, failure to thrive and metabolic abnormalities. A lack of the enzyme ADA allows accumulation of toxic metabolites causing defects of both cell mediated and humoral immunity leading to ADA severe combined immune deficiency (SCID), a condition that can be fatal in early infancy if left untreated. Hematopoietic stem cell transplant is curative but is dependent on a good donor match. Other therapeutic options include enzyme replacement therapy (ERT) with pegademase bovine (PEG-ADA) and more recently gene therapy. PEG-ADA has been used in over 150 patients worldwide and has allowed stabilization of patients awaiting more definitive treatment with hematopoietic stem cell transplant. It affords both metabolic detoxification and protective immune function with patients remaining clinically well, but immune reconstitution is often suboptimal and may not be long lived. We discuss the pharmacokinetics, immune reconstitution, effects on systemic disease and side effects of treatment with PEG-ADA. We also review the long-term outcome of patients receiving ERT and discuss the role of PEG-ADA in the management of infants and children with ADA-SCID, alongside other therapeutic options.

  9. Current microbiology of percutaneous endoscopic gastrostomy tube (PEG tube) insertion site infections in patients with cancer.

    Science.gov (United States)

    Rolston, Kenneth V I; Mihu, Coralia; Tarrand, Jeffrey J

    2011-08-01

    Percutaneous endoscopic gastrostomy (PEG) is frequently used to provide enteral access in cancer patients who are unable to swallow. Infection is an important complication in this setting. Current microbiological data are needed to guide infection prevention and treatment strategies. The microbiological records of our institution (a 550-bed comprehensive cancer center) were retrospectively reviewed over an 8-month study period in order to identify patients who developed PEG tube insertion site infections, and review their microbiological details and susceptibility/resistance data. Fifty-eight episodes of PEG tube insertion site infections were identified. Of these, 31 (53%) were monomicrobial, and the rest were polymicrobial. The most common organisms isolated were Candida species, Staphylococcus aureus, and Pseudomonas aeruginosa. All infections were local (cellulitis, complicated skin, and skin structure infections including abdominal wall abscess) with no cases of concomitant bacteremia being documented. Most of the organisms isolated were susceptible to commonly used antimicrobial agents, although some quinolone-resistant and some multidrug-resistant organisms were isolated. This retrospective study provides descriptive data regarding PEG tube insertion site infections. These data have helped us update institutional guidelines for infection prevention and treatment as part of our focus on antimicrobial stewardship.

  10. Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering.

    Science.gov (United States)

    Rennerfeldt, Deena A; Renth, Amanda N; Talata, Zsolt; Gehrke, Stevin H; Detamore, Michael S

    2013-11-01

    Hydrogels are attractive for tissue engineering applications due to their incredible versatility, but they can be limited in cartilage tissue engineering applications due to inadequate mechanical performance. In an effort to address this limitation, our team previously reported the drastic improvement in the mechanical performance of interpenetrating networks (IPNs) of poly(ethylene glycol) diacrylate (PEG-DA) and agarose relative to pure PEG-DA and agarose networks. The goal of the current study was specifically to determine the relative importance of PEG-DA concentration, agarose concentration, and PEG-DA molecular weight in controlling mechanical performance, swelling characteristics, and network parameters. IPNs consistently had compressive and shear moduli greater than the additive sum of either single network when compared to pure PEG-DA gels with a similar PEG-DA content. IPNs withstood a maximum stress of up to 4.0 MPa in unconfined compression, with increased PEG-DA molecular weight being the greatest contributing factor to improved failure properties. However, aside from failure properties, PEG-DA concentration was the most influential factor for the large majority of properties. Increasing the agarose and PEG-DA concentrations as well as the PEG-DA molecular weight of agarose/PEG-DA IPNs and pure PEG-DA gels improved moduli and maximum stresses by as much as an order of magnitude or greater compared to pure PEG-DA gels in our previous studies. Although the viability of encapsulated chondrocytes was not significantly affected by IPN formulation, glycosaminoglycan (GAG) content was significantly influenced, with a 12-fold increase over a three-week period in gels with a lower PEG-DA concentration. These results suggest that mechanical performance of IPNs may be tuned with partial but not complete independence from biological performance of encapsulated cells. © 2013 Elsevier Ltd. All rights reserved.

  11. Defined PEG smears as an alternative approach to enhance the search for crystallization conditions and crystal-quality improvement in reduced screens

    Energy Technology Data Exchange (ETDEWEB)

    Chaikuad, Apirat, E-mail: apirat.chaikuad@sgc.ox.ac.uk [University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ (United Kingdom); Knapp, Stefan [University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ (United Kingdom); Johann Wolfgang Goethe-University, Building N240 Room 3.03, Max-von-Laue-Strasse 9, 60438 Frankfurt am Main (Germany); Delft, Frank von, E-mail: apirat.chaikuad@sgc.ox.ac.uk [University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ (United Kingdom)

    2015-07-28

    An alternative strategy for PEG sampling is suggested through the use of four newly defined PEG smears to enhance chemical space in reduced screens with a benefit towards protein crystallization. The quest for an optimal limited set of effective crystallization conditions remains a challenge in macromolecular crystallography, an issue that is complicated by the large number of chemicals which have been deemed to be suitable for promoting crystal growth. The lack of rational approaches towards the selection of successful chemical space and representative combinations has led to significant overlapping conditions, which are currently present in a multitude of commercially available crystallization screens. Here, an alternative approach to the sampling of widely used PEG precipitants is suggested through the use of PEG smears, which are mixtures of different PEGs with a requirement of either neutral or cooperatively positive effects of each component on crystal growth. Four newly defined smears were classified by molecular-weight groups and enabled the preservation of specific properties related to different polymer sizes. These smears not only allowed a wide coverage of properties of these polymers, but also reduced PEG variables, enabling greater sampling of other parameters such as buffers and additives. The efficiency of the smear-based screens was evaluated on more than 220 diverse recombinant human proteins, which overall revealed a good initial crystallization success rate of nearly 50%. In addition, in several cases successful crystallizations were only obtained using PEG smears, while various commercial screens failed to yield crystals. The defined smears therefore offer an alternative approach towards PEG sampling, which will benefit the design of crystallization screens sampling a wide chemical space of this key precipitant.

  12. A novel vehicle for local protein delivery to the inner ear: injectable and biodegradable thermosensitive hydrogel loaded with PLGA nanoparticles.

    Science.gov (United States)

    Dai, Juan; Long, Wei; Liang, Zhongping; Wen, Lu; Yang, Fan; Chen, Gang

    2018-01-01

    Delivery of biomacromolecular drugs into the inner ear is challenging, mainly because of their inherent instability as well as physiological and anatomical barriers. Therefore, protein-friendly, hydrogel-based delivery systems following local administration are being developed for inner ear therapy. Herein, biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing interferon α-2 b (IFN α-2 b) were loaded in chitosan/glycerophosphate (CS/GP)-based thermosensitive hydrogel for IFN delivery by intratympanic injection. The injectable hydrogel possessed a physiological pH and formed semi-solid gel at 37 °C, with good swelling and deswelling properties. The CS/GP hydrogel could slowly degrade as visualized by scanning electron microscopy (SEM). The presence of NPs in CS/GP gel largely influenced in vitro drug release. In the guinea pig cochlea, a 1.5- to 3-fold increase in the drug exposure time of NPs-CS/GP was found than those of the solution, NPs and IFN-loaded hydrogel. Most importantly, a prolonged residence time was attained without obvious histological changes in the inner ear. This biodegradable, injectable, and thermosensitive NPs-CS/GP system may allow longer delivery of protein drugs to the inner ear, thus may be a potential novel vehicle for inner ear therapy.

  13. Cationic nanoparticles with quaternary ammonium-functionalized PLGA–PEG-based copolymers for potent gene transfection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan-Hsung [Kaohsiung Medical University, School of Dentistry, College of Dental Medicine (China); Fu, Yin-Chih [Kaohsiung Medical University, Graduate Institute of Medicine, College of Medicine (China); Chiu, Hui-Chi [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry, College of Life Science (China); Wang, Chau-Zen [Kaohsiung Medical University, Department of Physiology, College of Medicine (China); Lo, Shao-Ping [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry, College of Life Science (China); Ho, Mei-Ling [Kaohsiung Medical University, Department of Physiology, College of Medicine (China); Liu, Po-Len [Kaohsiung Medical University, Department of Respiratory Therapy, College of Medicine (China); Wang, Chih-Kuang, E-mail: ckwang@kmu.edu.tw [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry, College of Life Science (China)

    2013-11-15

    The objective of the present work was to develop new cationic nanoparticles (cNPs) with amphiphilic cationic copolymers for the delivery of plasmid DNA (pDNA). Cationic copolymers were built on the synthesis of quaternary ammonium salt compounds from diethylenetriamine (DETA) to include the positively charged head group and amphiphilic multi-grafts. PLGA-phe-PEG-qDETA (PPD), phe-PEG-qDETA-PLGA (PDP), and PLGA-phe-PEG-qDETA-PLGA (PPDP) cationic copolymers were created by this moiety of DETA quaternary ammonium, heterobifunctional polyethylene glycol (COOH-PEG-NH{sub 2}), phenylalanine (phe), and poly(lactic-co-glycolic acid) (PLGA). These new cNPs were prepared by the water miscible solvent displacement method. They exhibit good pDNA binding ability, as shown in a retardation assay that occurred at a particle size of ∼217 nm. The zeta potential was approximately +21 mV when the cNP concentration was 25 mg/ml. The new cNPs also have a better buffering capacity than PLGA NPs. However, the pDNA binding ability was demonstrated starting at a weight ratio of approximately 6.25 cNPs/pDNA. Gene transfection results showed that these cNPs had transfection effects similar to those of Lipofectamine 2000 in 293T cells. Furthermore, cNPs can also transfect human adipose-derived stem cells. The results indicate that the newly developed cNP is a promising candidate for a novel gene delivery vehicle.

  14. Biofabrication and in vitro study of hydroxyapatite/mPEG–PCL–mPEG scaffolds for bone tissue engineering using air pressure-aided deposition technology

    International Nuclear Information System (INIS)

    Jiang, Cho-Pei; Chen, Yo-Yu; Hsieh, Min-Fa

    2013-01-01

    The aims of this study were to fabricate biopolymer and biocomposite scaffolds for bone tissue engineering by an air pressure-aided deposition system and to carry out osteoblast cell culture tests to validate the biocompatibility of fabricated scaffolds. A mPEG–PCL–mPEG triblock copolymer was synthesized as a biopolymer material. Biocomposite material was composed of synthesized biopolymer and hydroxyapatite (HA) with a mean diameter of 100 μm. The weight ratio of HA added to the synthesized biopolymer was 0.1, 0.25, 0.5 and 1. The experimental results show that the maximum average compressive strength of biocomposite scaffolds, made of weight ratio 0.5, with mean pore size of 410 μm (porosity 81%) is 18.38 MPa which is two times stronger than that of biopolymer scaffolds. Osteoblast cells, MC3T3-E1, were seeded on both types of fabricated scaffolds to validate the biocompatibility using methylthianzol tetrazolium (MTT) assay and cell morphology observation. After 28 days of in vitro culturing, the seeded osteoblasts were well distributed in the interior of both types of scaffolds. Furthermore, MTT experimental results show that the cell viability of the biocomposite scaffold is higher than that of the biopolymer scaffold. This indicates that adding HA into synthesized biopolymer can enhance compressive strength and the proliferation of the osteoblast cell. Highlights: ► A mPEG-PCL-mPEG copolymer was synthesized as a biopolymer. ► Biocomposite was made of adding hydroxyapatite (HA) in biopolymer. ► Biopolyer and biocomposite scaffolds were made by an air pressure-aided deposition system. ► Average compressive strength of biocomposite scaffold is 18.38 MPa. ► After 28 days in vitro cell culturing, adding HA into biopolymer can enhance the proliferation.

  15. Performance Analysis of Iterative Decoding Algorithms for PEG LDPC Codes in Nakagami Fading Channels

    Directory of Open Access Journals (Sweden)

    O. Al Rasheed

    2013-11-01

    Full Text Available In this paper we give a comparative analysis of decoding algorithms of Low Density Parity Check (LDPC codes in a channel with the Nakagami distribution of the fading envelope. We consider the Progressive Edge-Growth (PEG method and Improved PEG method for the parity check matrix construction, which can be used to avoid short girths, small trapping sets and a high level of error floor. A comparative analysis of several classes of LDPC codes in various propagation conditions and decoded using different decoding algorithms is also presented.

  16. Toxicity of PEG-Coated CoFe2O4 Nanoparticles with Treatment Effect of Curcumin

    Science.gov (United States)

    Akhtar, Shahnaz; An, Wenzhen; Niu, Xiaoying; Li, Kang; Anwar, Shahzad; Maaz, Khan; Maqbool, Muhammad; Gao, Lan

    2018-02-01

    In this work, CoFe2O4 nanoparticles coated with polyethylene glycol (PEG) were successfully synthesized via a hydrothermal technique. Morphological studies of the samples confirmed the formation of polycrystalline pure-phase PEG-CoFe2O4 nanoparticles with sizes of about 24 nm. Toxicity induced by CoFe2O4 nanoparticles was investigated, and biological assays were performed to check the toxicity effects of CoFe2O4 nanoparticles. Moreover, the healing effect of toxicity induced in living organisms was studied using curcumin and it was found that biochemical indexes detoxified and improved to reach its normal level after curcumin administration. Thus, PEG-coated CoFe2O4 synthesized through a hydrothermal method can be utilized in biomedical applications and curcumin, which is a natural chemical with no side effects, can be used for the treatment of toxicity induced by the nanoparticles in living organisms.

  17. Ionic networks derived from the protonation of dendritic amines with carboxylic acid end‐functionalized PEGs

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Skov, Anne Ladegaard; Hvilsted, Søren

    2013-01-01

    The synthesis and characterization of novel ionic networks linked by the ammonium salts of poly(propylene imine) (PPI) dendrimers of the first (PPI G1) and second (PPI G2) generation and two short bis carboxymethyl ether terminated poly(ethylene glycol)s (DiCOOH‐PEG) with different molecular...... weights (Mn ∼ 250 and Mn ∼ 600) are reported. Likewise, an ionic network based on PPI G1 and a long αω‐dicarboxylic acid functionalized PEG (Mn ∼ 4800) were evaluated. Simpler ionic structures based on tris(2‐aminoethyl)amine or hexamethylene diamine and the short DiCOOH‐PEGs are also investigated....... The ionic structures formed were confirmed by differential scanning calorimetry, Fourier Transform Infrared spectroscopy in the attenuated‐total‐reflection mode, and 1H‐13C NMR spectroscopy. A comprehensive 1H NMR analysis revealed that only the primary amines of the PPI G1 dendrimer residing...

  18. Xingnaojing mPEG2000-PLA modified microemulsion for transnasal delivery: pharmacokinetic and brain-targeting evaluation.

    Science.gov (United States)

    Wen, Ran; Zhang, Qing; Xu, Pan; Bai, Jie; Li, Pengyue; Du, Shouying; Lu, Yang

    2016-01-01

    Xingnaojing microemulsion (XNJ-M) administered intranasally is used for stroke treatment. In order to decrease the XNJ-M-induced mucosal irritation, XNJ-M modified by mPEG2000-PLA (XNJ-MM) were prepared in a previous work. The present work aimed to assess the impact of mPEG2000-PLA on pharmacokinetic features and brain-targeting ability of XNJ-M. The bioavailability and brain-target effects of borneol and geniposide in XNJ-M and XNJ-MM were compared in mice after intravenous (i.v.) and intranasal (i.n.) administrations. Gas chromatography, high-performance liquid chromatography, and ultra-performance liquid chromatography/tandem mass spectrometry methods were developed for the quantification of borneol and geniposide. Blood and brain samples were collected from mice at different time points after i.v. and i.n. treatments with borneol at 8.0 mg/kg, geniposide at 4.12 mg/kg. In addition, near-infrared fluorescence dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indotricarbocyanine iodide was loaded into microemulsions to evaluate the brain-targeting ability of XNJ-M and XNJ-MM by near-infrared fluorescence imaging in vivo and ex vivo. For XNJ-M and XNJ-MM, the relative brain targeted coefficients (Re) were 134.59% and 198.09% (borneol), 89.70% and 188.33% (geniposide), respectively. Besides, significant near-infrared fluorescent signal was detected in the brain after i.n. administration of microemulsions, compared with that of groups for i.v. administration. These findings indicated that mPEG2000-PLA modified microemulsion improved drug entry into blood and brain compared with normal microemulsion: the introduction of mPEG2000-PLA in microemulsion resulted in brain-targeting enhancement of both fat-soluble and water-soluble drugs. These findings provide a basis for the significance of mPEG2000-PLA addition in microemulsion, defining its effects on the drugs in microemulsion.

  19. Noninvasive imaging of tumor integrin expression using 18F-labeled RGD dimer peptide with PEG4 linkers

    International Nuclear Information System (INIS)

    Liu, Zhaofei; Liu, Shuanglong; Wang, Fan; Liu, Shuang; Chen, Xiaoyuan

    2009-01-01

    Various radiolabeled Arg-Gly-Asp (RGD) peptides have been previously investigated for tumor integrin α v β 3 imaging. To further develop RGD radiotracers with enhanced tumor-targeting efficacy and improved in vivo pharmacokinetics, we designed a new RGD homodimeric peptide with two PEG 4 spacers (PEG 4 = 15-amino-4,7,10,13-tetraoxapentadecanoic acid) between the two monomeric RGD motifs and one PEG 4 linker on the glutamate α-amino group ( 18 F-labeled PEG 4 -E[PEG 4 -c(RGDfK)] 2 , P-PRGD2), as a promising agent for noninvasive imaging of integrin expression in mouse models. P-PRGD2 was labeled with 18 F via 4-nitrophenyl 2- 18 F-fluoropropionate ( 18 F-FP) prosthetic group. In vitro and in vivo characteristics of the new dimeric RGD peptide tracer 18 F-FP-P-PRGD2 were investigated and compared with those of 18 F-FP-P-RGD2 ( 18 F-labeled RGD dimer without two PEG 4 spacers between the two RGD motifs). The ability of 18 F-FP-P-PRGD2 to image tumor vascular integrin expression was evaluated in a 4T1 murine breast tumor model. With the insertion of two PEG 4 spacers between the two RGD motifs, 18 F-FP-P-PRGD2 showed enhanced integrin α v β 3 -binding affinity, increased tumor uptake and tumor-to-nontumor background ratios compared with 18 F-FP-P-RGD2 in U87MG tumors. MicroPET imaging with 18 F-FP-P-PRGD2 revealed high tumor contrast and low background in tumor-bearing nude mice. Biodistribution studies confirmed the in vivo integrin α v β 3 -binding specificity of 18 F-FP-P-RGD2. 18 F-FP-P-PRGD2 can specifically image integrin α v β 3 on the activated endothelial cells of tumor neovasculature. 18 F-FP-P-PRGD2 can provide important information on integrin expression on the tumor vasculature. The high integrin binding affinity and specificity, excellent pharmacokinetic properties and metabolic stability make the new RGD dimeric tracer 18 F-FP-P-PRGD2 a promising agent for PET imaging of tumor angiogenesis and for monitoring the efficacy of antiangiogenic

  20. Efficient SO2 capture by amine functionalized PEG.

    Science.gov (United States)

    Yang, Dezhong; Hou, Minqiang; Ning, Hui; Zhang, Jianling; Ma, Jun; Han, Buxing

    2013-11-07

    Polyethylene glycols (PEGs) are a class of non-toxic, non-volatile, biocompatible, and widely available polymers. In this work, we synthesized N-ethyl-N-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)-2-aminoethanol (EE3AE) that combines the properties of PEG and amines, and N-decyl-N-ethyl-2-aminoethanol (DEAE). Their performances to capture SO2 were studied at different temperatures, pressures, and absorption times. The interaction between the absorbents and SO2 were characterized by NMR and FTIR techniques. It was demonstrated that both EE3AE and DEAE could absorb SO2 efficiently, and there existed chemical and physical interactions between the absorbents and SO2. In particular, the absorption capacity of EE3AE could be as high as 1.09 g SO2 per g EE3AE at 1 atm. The absorption capacity of EE3AE was much larger than that of DEAE because the ether group in the EE3AE interacted with SO2 more strongly than the alkyl group in the DEAE. The SO2 absorbed by EE3AE could be stripped out by bubbling N2 or by applying a vacuum and the EE3AE could be reused. Moreover, both absorbents exhibited a high SO2-CO2 selectivity.

  1. New biodegradable dextran-based hydrogels for protein delivery: Synthesis and characterization.

    Science.gov (United States)

    Pacelli, Settimio; Paolicelli, Patrizia; Casadei, Maria Antonietta

    2015-08-01

    A new derivative of dextran grafted with polyethylene glycol methacrylate through a carbonate bond (DEX-PEG-MA) has been synthesized and characterized. The photo-crosslinking reaction of DEX-PEG-MA allowed the obtainment of biodegradable networks tested for their mechanical and release properties. The new hydrogels were compared with those made of dextran methacrylate (DEX-MA), often employed as drug delivery systems of small molecules. The inclusion of PEG as a spacer created additional interactions among the polymeric chains improving the extreme fragility and lack of hardness typical of gels made of DEX-MA. Moreover, the different behavior in terms of swelling and degradability of the networks was able to affect the release of a model macromolecule over time, making DEX-PEG-MA matrices suitable candidates for the delivery of high molecular weight peptides. Interestingly, the combination of the two dextran derivatives showed intermediate ability to modulate the release of high molecular weight macromolecules. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Synthesis and Characterization of Biodegradable Amphiphilic Star and Y-Shaped Block Copolymers as Potential Carriers for Vinorelbine

    Directory of Open Access Journals (Sweden)

    Fatemeh Bahadori

    2014-01-01

    Full Text Available Two amphiphilic block copolymers using hydrophobic poly(ε-caprolactone (PCL and hydrophilic poly(ethylene glycol (PEG were successfully synthesized. One of them is an (A-b-B4 type star polymer [(PCL-b-PEG4] and the other one is a Y-shaped PEG–(PCL2. A star-shaped polymer (PCL-b-PEG4 was prepared by ring-opening polymerization (ROP of ε-caprolactone continued by click reaction of (PCL-azide4 and PEG-alkyne. The synthesis of Y-shaped PEG–(PCL2 block copolymer was carried out via Diels-Alder click reaction of a furan protected maleimide end-functionalized PEG (PEG-MI with an anthracene end-functionalized PCL following the ROP of ε-caprolactone. The characterization of micelles is carried out using both materials in aqueous media as drug delivery vehicles, which showed satisfying results and enhanced the cytotoxic effect of the anti-cancer drug vinorelbine (VLB. However, micelles consisted of Y-shaped unimers were found to be more convenient for delivery of hydrophobic drugs such as VLB because they formed in lower concentration, carrying a higher amount of drugs and owing a monomodal distribution. We concluded that the free tails of hydrophobic chains in Y-shaped block copolymer facilitate the assembly of amphiphilic material in water to form micelles.

  3. Blends of PHB/PEG: obtention of matrices for use as controlled drug release systems; Obtencao de blendas de PHB/PEG para matrizes de sistemas micro e nanoestruturados visando aplicacao em liberacao controlada de farmacos

    Energy Technology Data Exchange (ETDEWEB)

    Catoni, S.E.M.; Gomes, C.A.T.; Trindade, K.N.S.; Schneider, A.L.S.; Pezzin, A.P.T., E-mail: sara.elisamoreira@hotmail.co [Universidade da Regiao de Joinville (UNIVILLE), SC (Brazil); Soldi, V. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2010-07-01

    Different materials have been used in the development of micro-and nanostructured systems for drug release. In general, poly(3-hydroxybutyrate) (PHB) matrixes have high crystallinity degree, justifying its slow degradation. This feature makes the attack of enzymes more difficult. Thus, the surface modification with hydrophilic polymers such as poly(ethylene glycol) (PEG) has been investigated in order to obtain particles which are not recognized and captured by phagocytic cells after in vivo administration, staying for a longer in the systemic circulation. In this work, PHB/PEG films were prepared by casting in different proportions and characterized by XRD, DSC, SEM, GPC and TGA. The films presented high crystallinity degree and showed uniformity, except the 50/50 composition which showed the presence of two phases. The results revealed that increasing percentage of PEG, the Tm of PHB was decreased, the thermal stability was dramatically decreased and molecular weight of the samples was lower. (author)

  4. 3D- Printed Poly(ε-caprolactone) Scaffold Integrated with Cell-laden Chitosan Hydrogels for Bone Tissue Engineering

    OpenAIRE

    Dong, Liang; Wang, Shao-Jie; Zhao, Xin-Rong; Zhu, Yu-Fang; Yu, Jia-Kuo

    2017-01-01

    Synthetic polymeric scaffolds are commonly used in bone tissue engineering (BTE) due to their biocompatibility and adequate mechanical properties. However, their hydrophobicity and the lack of specific cell recognition sites confined their practical application. In this study, to improve the cell seeding efficiency and osteoinductivity, an injectable thermo-sensitive chitosan hydrogel (CSG) was incorporated into a 3D-printed poly(ε-caprolactone) (PCL) scaffold to form a hybrid scaffold. To de...

  5. Clickable and imageable multiblock polymer micelles with magnetically guided and PEG-switched targeting and release property for precise tumor theranosis.

    Science.gov (United States)

    Wei, Jing; Shuai, Xiaoyu; Wang, Rui; He, Xueling; Li, Yiwen; Ding, Mingming; Li, Jiehua; Tan, Hong; Fu, Qiang

    2017-11-01

    Targeted delivery of therapeutics and diagnostics using nanotechnology holds great promise to minimize the side effects of conventional chemotherapy and enable specific and real-time detection of diseases. To realize this goal, we report a clickable and imageable nanovehicle assembled from multiblock polyurethanes (MPUs). The soft segments of the polymers are based on detachable poly(ethylene glycol) (PEG) and degradable poly(ε-caprolactone) (PCL), and the hard segments are constructed from lysine- and cystine-derivatives bearing reduction-responsive disulfide linkages and click-active alkynyl moieties, allowing for post-conjugation of targeting ligands via a click chemistry. It was found that the cleavage of PEG corona bearing a pH-sensitive benzoic-imine linkage (BPEG) could act as an on-off switch, which is capable of activating the clicked targeting ligands under extracellular acidic condition, followed by triggering the core degradation and payload release within tumor cells. In combination with superparamagnetic iron oxide nanoparticles (SPION) clustered within the micellar core, the MPUs exhibit excellent magnetic resonance imaging (MRI) contrast effects and T 2 relaxation in vitro, as well as magnetically guided MR imaging and multimodal targeting of therapeutics to tumor precisely, leading to significant inhibition of cancer with minimal side effect. This work provides a safe and versatile platform for the further development of smart theranostic systems for potential magnetically-targeted and imaging-guided personalized medicine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Free radical scavenging injectable hydrogels for regenerative therapy.

    Science.gov (United States)

    Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2017-02-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Effect of PEG and water-soluble chitosan coating on moxifloxacin-loaded PLGA long-circulating nanoparticles.

    Science.gov (United States)

    Mustafa, Sanaul; Devi, V Kusum; Pai, Roopa S

    2017-02-01

    Moxifloxacin (MOX) is a Mycobacterium tuberculosis DNA gyrase inhibitor. Due to its intense hydrophilicity, MOX is cleared from the body within 24 h and required for repetitive doses which may then result in hepatotoxicity and acquisition of MOX resistant-TB, related with its use. To overcome the aforementioned limitations, the current study aimed to develop PLGA nanoparticles (PLGA NPs), to act as an efficient carrier for controlled delivery of MOX. To achieve a substantial extension in blood circulation, a combined design, affixation of polyethylene glycol (PEG) to MOX-PLGA NPs and adsorption of water-soluble chitosan (WSC) (cationic deacetylated chitin) to particle surface, was rose for surface modification of NPs. Surface modified NPs (MOX-PEG-WSC NPs) were prepared to provide controlled delivery and circulate in the bloodstream for an extended period of time, thus minimizing dosing frequency. In vivo pharmacokinetic and in vivo biodistribution following oral administration were investigated. NP surface charge was closed to neutral +4.76 mV and significantly affected by the WSC coating. MOX-PEG-WSC NPs presented striking prolongation in blood circulation, reduced protein binding, and long-drawn-out the blood circulation half-life with resultant reduced liver sequestration vis-à-vis MOX-PLGA NPs. The studies, therefore, indicate the successful formulation development of MOX-PEG-WSC NPs that showed sustained release behavior from nanoparticles which indicates low frequency of dosing.

  8. PEG 3350 (Transipeg) versus lactulose in the treatment of childhood functional constipation: a double blind, randomised, controlled, multicentre trial

    NARCIS (Netherlands)

    Voskuijl, W.; de Lorijn, F.; Verwijs, W.; Hogeman, P.; Heijmans, J.; Mäkel, W.; Taminiau, J.; Benninga, M.

    2004-01-01

    Background: Recently, polyethylene glycol ( PEG 3350) has been suggested as a good alternative laxative to lactulose as a treatment option in paediatric constipation. However, no large randomised controlled trials exist evaluating the efficacy of either laxative. Aims: To compare PEG 3350 (

  9. Blood gas analysis, anion gap, and strong ion difference in horses treated with polyethylene glycol balanced solution (PEG 3350 or enteral and parenteral electrolyte solutions

    Directory of Open Access Journals (Sweden)

    Cláudio Luís Nina Gomes

    2014-06-01

    Full Text Available Large volumes of different electrolytes solutions are commonly used for ingesta hydration in horses with large colon impaction, but little is known about their consequences to blood acid-base balance. To evaluate the effects of PEG 3350 or enteral and parenteral electrolyte solutions on the blood gas analysis, anion gap and strong ion difference, five adult female horses were used in a 5x5 latin square design. The animals were divided in five groups and distributed to each of the following treatments: NaCl (0.9% sodium chloride solution; EES (enteral electrolyte solution, EES+LR (EES plus lactated Ringer's solution; PEG (balanced solution with PEG 3350 and PEG+LR (PEG plus lactated Ringer's solution. Treatments PEG or PEG + LR did not change or promoted minimal changes, while the EES caused a slight decrease in pH, but its association with lactated Ringer's solution induced increase in AG and SID values, as well as caused hypernatremia. In turn, the treatment NaCl generated metabolic acidosis. PEG 3350 did not alter the acid-base balance. Despite it's slight acidifying effect, the enteral electrolyte solution (EES did not cause clinically relevant changes.

  10. Hydroxynortriptyline of Empty Fruit Bunches Fibre using Polyethylene glycol (PEG)

    International Nuclear Information System (INIS)

    Noreen, F.M.Z.; Sarani Zakaria

    2013-01-01

    The aim of this study was to investigate the reaction of oil palm empty fruit bunches fibre (EFBF) via chemical modification and hydroxynortriptyline method using polyethylene glycol (PEG). The first stage was the modification of EFB fibre using NaOH and isopropanol. The next stage was the preparation of hydroxypropylated-empty fruit bunches fibre (HP-EFBF), using different molecular weight of PEG (6,000, 8,000 and 10,000). The characterisation involved in this study were conducted by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), determination of kinetic activation energy (E a ), X-ray diffraction (XRD), cellulose crystallinity index (CrI) and weight increment of the HP-EFB fibre. SEM results showed the surface of HP-EFBF swelled and craters formed along the surface of the fibre. IR spectrum also showed OH stretching band in EFB without treatment is 3402 cm -1 , but after hydroxynortriptyline process, the OH stretching band in HP-EFBF (10000, 8000 and 6000) slightly shifted to 3392, 3384 and 3370 cm -1 , respectively. TGA showed the thermal stability of HP-EFBF 6,000 was lower than HP-EFBF 8,000 and 10,000. After chemical modification, the activation energy, E a increased from 32.4 to 51.9 kJ/ mol more than EFB without treatment, 12.5 kJ/ mol. XRD showed that diffraction peak (002) shifted to the smaller 2θ angle and the peaks (101, 10I) disappeared after hydroxynortriptyline process. Crystallinity index, of EFB without treatment decreased from 27 % to 25 % after chemical modification. The higher the molecular weight of the PEG, the greater the weight increment of the HP-EFBF. (author)

  11. Thiol-PEG-carboxyl-stabilized Fe2O3/Au nanoparticles targeted to CD105: Synthesis, characterization and application in MR imaging of tumor angiogenesis

    International Nuclear Information System (INIS)

    Zhang, Song; Gong, Mingfu; Zhang, Dong; Yang, Hua; Gao, Fabao; Zou, Liguang

    2014-01-01

    Objective: To detect tumor angiogenesis in tumor-bearing mice using thiol-PEG-carboxyl-stabilized Fe 2 O 3 /Au nanoparticles targeted to CD105 on magnetic resonance imaging (MRI). Methods: Fe 2 O 3 /Au nanoparticles (hybrids) were prepared by reducing Au 3+ on the surface of Fe 2 O 3 nanoparticles. Hybrids were stabilized with thiol-PEG-carboxyl via the Au–S covalent bond, and further conjugated with anti-CD105 antibodies through amide linkages. Characteristics of the hybrid-PEG-CD105 nanoparticles were evaluated. Using these nanoparticles, the labeling specificity of human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. MRI T2*-weighted images were obtained at different time points after intravenous administration of the hybrid-PEG-CD105 nanoparticles in the tumor-bearing mice. After MR imaging, the breast cancer xenografts were immediately resected for immunohistochemistry staining and Prussian blue staining to measure the tumor microvessel density (MVD) and evaluate the labeling of blood microvessels by the hybrid-PEG-CD105 nanoparticles in vivo. Results: The mean diameter of the hybrid-PEG-CD105 nanoparticles was 56.6 ± 8.0 nm, as measured by transmission electron microscopy (TEM). Immune activity of the hybrid-PEG-CD105 nanoparticles was 53% of that of the anti-CD105 antibody, as detected by enzyme-linked immunosorbent assay (ELISA). The specific binding of HUVECs with the hybrid-PEG-CD105 nanoparticles was proved by immunostaining and Prussian blue staining in vitro. For breast cancer xenografts, the combination of the hybrid-PEG-CD105 nanoparticles with blood microvessels was detectable by MRI after 60 min administration of the contrast agent. The T2* relative signal intensity (SI R ) was positively correlated with the tumor MVD (R 2 = 0.8972). Conclusion: Anti-CD105 antibody-coupled, thiol-PEG-carboxyl-stabilized core–shell Fe 2 O 3 /Au nanoparticles can efficiently target CD105 expressed by HUVECs. Furthermore, the hybrid-PEG-CD105

  12. Hydrogel formulation determines cell fate of fetal and adult neural progenitor cells

    Directory of Open Access Journals (Sweden)

    Emily R. Aurand

    2014-01-01

    Full Text Available Hydrogels provide a unique tool for neural tissue engineering. These materials can be customized for certain functions, i.e. to provide cell/drug delivery or act as a physical scaffold. Unfortunately, hydrogel complexities can negatively impact their biocompatibility, resulting in unintended consequences. These adverse effects may be combated with a better understanding of hydrogel chemical, physical, and mechanical properties, and how these properties affect encapsulated neural cells. We defined the polymerization and degradation rates and compressive moduli of 25 hydrogels formulated from different concentrations of hyaluronic acid (HA and poly(ethylene glycol (PEG. Changes in compressive modulus were driven primarily by the HA concentration. The in vitro biocompatibility of fetal-derived (fNPC and adult-derived (aNPC neural progenitor cells was dependent on hydrogel formulation. Acute survival of fNPC benefited from hydrogel encapsulation. NPC differentiation was divergent: fNPC differentiated into mostly glial cells, compared with neuronal differentiation of aNPC. Differentiation was influenced in part by the hydrogel mechanical properties. This study indicates that there can be a wide range of HA and PEG hydrogels compatible with NPC. Additionally, this is the first study comparing hydrogel encapsulation of NPC derived from different aged sources, with data suggesting that fNPC and aNPC respond dissimilarly within the same hydrogel formulation.

  13. Randomised clinical trial: macrogol/PEG 3350+electrolytes versus prucalopride in the treatment of chronic constipation -- a comparison in a controlled environment.

    Science.gov (United States)

    Cinca, R; Chera, D; Gruss, H-J; Halphen, M

    2013-05-01

    Constipation is a common condition for which PEG 3350 is an established treatment and prucalopride has recently been approved for this indication. To compare the efficacy, safety and impact on quality of life (QoL) of PEG 3350 plus electrolytes (PEG 3350+E) vs. prucalopride in females with chronic constipation (CC) in whom laxatives have previously failed to provide adequate relief. In this single-centre, randomised, double-blind, double-dummy study, patients with CC [PEG 3350+E (N = 120) or 1-2 mg prucalopride (N = 120) daily for 28 days following a 14-day run-in period. The primary endpoint was the proportion of patients having ≥3 SCBMs during the last treatment week. Non-inferiority of PEG 3350+E to prucalopride was demonstrated in the per-protocol population [difference, 10.1% (66.67% vs. 56.52%), 97.5% lower confidence interval (CI) -2.7%, above the preset margin of -20%] and approached superiority in the modified intent-to-treat population (difference, 9.8%, 97.5% lower CI, -3.1%). Statistically significant differences in favour of PEG 3350+E were observed for most secondary variables (bowel movements, stool weight, consistency, time to next SCBM, patient perception of straining and completeness of defecation). Colonic transit time was dramatically reduced in both arms. Both treatments were well tolerated. PEG 3350+E was at least as effective as and generally better tolerated than prucalopride as a treatment for chronic constipation in this study population (NCT01251822; http://www.clinicaltrials.gov). © 2013 Blackwell Publishing Ltd.

  14. PLA-b-PEG/magnetite hyperthermic agent prepared by Ugi four component condensation

    Directory of Open Access Journals (Sweden)

    L. P. Icart

    2016-03-01

    Full Text Available Ugi four component condensation (UFCC, is an important tool for the synthesis of different types of bioconjugate species. In this study, a PLA-PEG/magnetite magnetic composite was prepared by a synthetic-route approach based on UFCC. In particular, poly(lactic acid (PLA was synthesized by autocatalytic polycondensation. Also, poly(ethyleneglycol bis-amine (bis-amine PEG was synthesized by two different methods: via carbonyldiimidazol (CDI/ethylenediamine (ED (75% yield and via chlorate monochlorated acetyl (CCA/ED (95% yield. All products were characterized by gel permeation chromatography (GPC, hydrogen-1 nuclear magnetic resonance (NMR 1H, Fourier transform infrared (FTIR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. In addition, magnetite was prepared and modified to generate aldehyde groups which are also necessary for UFCC. This product was characterized by DSC, TGA, X-ray diffraction (XRD and magnetic force (MF techniques. Also, the magnetic composite PLA-PEG/magnetite was synthesized by UFCC. The calculated yield was equal to 80%. Furthermore, magnetic microspheres were prepared by the procedure of emulsion solvent-evaporation and characterized by scanning electron microscopy (SEM and magnetic induction hyperthermia (MIH. The main contribution of these results is to propose a new application for UFCC in the preparation of biomasked magnetic drug delivery systems able to improve the cancer treatment and even the welfare of the patients.

  15. FUSE SPECTROSCOPIC ANALYSIS OF THE SLOWEST SYMBIOTIC NOVA AG PEG DURING QUIESCENCE

    Science.gov (United States)

    Sion, Edward Michael; Godon, Patrick; Katynski, Marcus; Mikolajewska, Joanna

    2018-01-01

    We present a far ultraviolet spectroscopic analysis of the slowest known symbiotic nova AG Peg (MIII giant + hot white dwarf; P_orb = 818.4 days) which underwent a nova explosion in 1850 followed by a very slow decline that did not end until ~ 1996, marking the beginning of queiscence. Eight years of quiescence ended in June 2015, when AG Peg exhibited a Z And-type outburst with an optical amplitude of ~ 3 magnitudes. We have carried out accretion disk and WD photosphere synthetic spectral modeling of a FUSE spectrum (Froning et al. 2014) obtained on June 5.618, 2003 during the quiescence intervai ~ 12 years before the 2015 outburst. The spectrum is heavily affected by ISM absorption as well as strong broad emission lines. We de-reddened the FUSE fluxes with E(B-V) = 0.10 which is the maximum galactic reddening in the direction of AG Peg and took the distance of 800 pc (Kenyon et al. 1993) but used a range of white dwarf masses, surface temperatures and disk inclination angles. Our analysis also incororates archival HST FOS spectra obtained in 1996 at the onset of quiescence, 147 years after the 1850 nova explosion. The results of our analysis are presented and implications are discussed.This work is supported in part by NASA ADP grant NNX17AF36G to Villanova University.

  16. Formation of Underbrushes on thiolated Poly (ethylene glycol) PEG monolayers by Oligoethylene glycol (OEG) terminated Alkane Thiols on Gold

    DEFF Research Database (Denmark)

    Lokanathan, Arcot R.

    2011-01-01

    Adding underbrushes of oligoethylene glycol (OEG) to monolayers of long chain PEG molecules on a surface is one of the strategies [1] in designing a suitable platform for antifouling purpose, where it is possible to have high graft density and molecular conformational freedom[4] simultaneously......, there by maximal retention of activity of covalently immobilised antifouling enzyme [2] on PEG surfaces along with resistance to protein adsorption[3]. Here we present some our studies on the addition of OEG thiol molecules over a self assembled monolayer of PEG thiol on gold. The kinetics of addition of OEG thiol...

  17. Two peg spade plate for distal radius fractures A novel technique

    Directory of Open Access Journals (Sweden)

    Sharad M Hardikar

    2015-01-01

    Conclusions: The two peg volar spade plate provides a stable subchondral support in comminuted intraarticular fractures and maintains reduction in osteoporotic fractures of the distal radius. Early mobilization with this implant helps in restoring wrist motion and to prevent development of wrist stiffness.

  18. Eco-friendly PEG-based controlled release nano-formulations of Mancozeb: Synthesis and bioefficacy evaluation against phytopathogenic fungi Alternaria solani and Sclerotium rolfsii.

    Science.gov (United States)

    Majumder, Sujan; Shakil, Najam A; Kumar, Jitendra; Banerjee, Tirthankar; Sinha, Parimal; Singh, Braj B; Garg, Parul

    2016-12-01

    Controlled release (CR) nano-formulations of Mancozeb (manganese-zinc double salt of N,N-bisdithiocarbamic acid), a protective fungicide, have been prepared using laboratory-synthesized poly(ethylene glycols) (PEGs)-based functionalized amphiphilic copolymers without using any surfactants or external additives. The release kinetics of the developed Mancozeb CR formulations were studied and compared with that of commercially available 42% suspension concentrate and 75% wettable powder. Maximum amount of Mancozeb was released on 42nd day for PEG-600 and octyl chain, PEG-1000 and octyl chain, and PEG-600 and hexadecyl chain, on 35th day for PEG-1000 and hexadecyl chain, on 28th day for PEG-1500 and octyl chain, PEG-2000 and octyl chain, PEG-1500 and hexadecyl chain, and PEG-2000 and hexadecyl chain in comparison to both commercial formulations (15th day). The diffusion exponent (n value) of Mancozeb in water ranged from 0.42 to 0.62 in tested formulations. The half-release (t 1/2 ) values ranged from 17.35 to 35.14 days, and the period of optimum availability of Mancozeb ranged from 18.54 to 35.42 days. Further, the in vitro bioefficacy evaluation of developed formulations was done against plant pathogenic fungi Alternaria solani and Sclerotium rolfsii by poison food technique. Effective dose for 50% inhibition in mgL -1 (ED 50 ) values of developed formulations varied from 1.31 to 2.79 mg L -1 for A. solani, and 1.60 to 3.14 mg L -1 for S. rolfsii. The present methodology is simple, economical, and eco-friendly for the development of environment-friendly CR formulations of Mancozeb. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, the maximum amount of active ingredient remains available for a reasonable period after application. In addition, the developed CR formulations were found to be suitable for fungicidal applications, allowing

  19. Strengthening injectable thermo-sensitive NIPAAm-g-chitosan hydrogels using chemical cross-linking of disulfide bonds as scaffolds for tissue engineering.

    Science.gov (United States)

    Wu, Shu-Wei; Liu, Xifeng; Miller, A Lee; Cheng, Yu-Shiuan; Yeh, Ming-Long; Lu, Lichun

    2018-07-15

    In the present study, we fabricated non-toxic, injectable, and thermo-sensitive NIPAAm-g-chitosan (NC) hydrogels with thiol modification for introduction of disulfide cross-linking strategy. Previously, NIPAAm and chitosan copolymer has been proven to have excellent biocompatibility, biodegradability and rapid phase transition after injection, suitable to serve as cell carriers or implanted scaffolds. However, weak mechanical properties significantly limit their potential for biomedical fields. In order to overcome this issue, we incorporated thiol side chains into chitosan by covalently conjugating N-acetyl-cysteine (NAC) with carbodiimide chemistry to strengthen mechanical properties. After oxidation of thiols into disulfide bonds, modified NC hydrogels did improve the compressive modulus over 9 folds (11.4 kPa). Oscillatory frequency sweep showed a positive correlation between storage modulus and cross-liking density as well. Additionally, there was no cytotoxicity observed to mesenchymal stem cells, fibroblasts and osteoblasts. We suggested that the thiol-modified thermo-sensitive polysaccharide hydrogels are promising to be a cell-laden biomaterial for tissue regeneration. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. A spectroscopic study of the deeply eclipsing dwarf nova IP Peg

    International Nuclear Information System (INIS)

    Marsh, T.R.

    1988-01-01

    Spectrophotometry of the dwarf novae IP Peg during quiescence is presented. The spectra have broad, double peaked emission lines on a blue continuum, characteristic of high-inclination dwarf novae. The emission lines are 96 per cent eclipsed and the orbital hump, which is strong in the continuum, is much weaker in the lines. We introduce a method for the analysis of radial velocities of emission lines which corrects for bias caused by disc asymmetries, and we determine the geometrical and physical parameters of IP Peg. The masses of the white dwarf and red star are Msub(W) = 1.09 ± 0.10 solar masses and Msub(R) = 0.64 ± 0.09 solar masses, and the orbital inclination is i = 79.3 ± 0.9 0 . The secondary star which has a radius Rsub(R) 0.49 ± 0.03 solar radii, lies near the main sequence mass-radius relation. (author)

  1. Cell suspension culture and mutants selection for resistance to PEG induced water stress in alfalfa (Medicago sativa L.)

    International Nuclear Information System (INIS)

    Zhang Xiaodong; Lin Tingan

    1994-01-01

    Elements affecting suspension cell culture in alfalfa (Medicago sativa L.) were studied and a method of rapid establishment of embryogenic suspension cell lines was introduced. Effects of γ ray irradiation on the growth of suspension cells were studied, and the optimum dose of irradiation for inducing mutants from suspension cells was about 20 ∼ 60 Gy. Effects of PEG and NaCl induced water stress on the growth of suspension cells were also investigated, and the results showed that the congregants of preliminary suspension culture were more susceptible than the established suspension cell lines. With 20 Gy of γ ray irradiation on suspension cell line (JL416), six clones were obtained with 70 days of selection on medium of 15% PEG (about-11 bar). A number of regenerated plants were obtained from these clones. One clone was also gained from medium containing 20% PEG (about-15 bar). The selected mutant cell lines (JP15 and JP20) has strong resistances to high concentration of PEG and NaCl induced water stress

  2. The storage capacity of cocoa seeds (Theobroma cacao L.) through giving Polyethylene Glycol (PEG) in the various of storage container

    Science.gov (United States)

    Lahay, R. R.; Misrun, S.; Sipayung, R.

    2018-02-01

    Cocoa is plant which it’s seed character is recalcitrant. Giving PEG and using various of storage containers was hoped to increase storage capacity of cocoa seeds as long as period of saving. The reseach was aimed to identify the storage capacity of cocoa seeds through giving PEG in the various of storage containers. Research took place in Hataram Jawa II, Kabupaten Simalungun, Propinsi Sumatera Utara, Indonesia. The method of this research is spit-split plot design with 3 replication. Storage period was put on main plot which was consisted of 4 level, PEG concentration was put on sub plot, consisted of 4 level and storage container was put on the sub sub plot consisted of 3 types. The results showed that until 4 days at storage with 45 % PEG concentration at all storage container, percentage of seed germination at storage can be decreased to be 2.90 %, and can be defensed until 16 days with 45 % PEG concentration at perforated plastic storage container. Percentage of molded seeds and seed moisture content were increased with added period of storage but seed moisture content was increased until 12 days at storage and was decreased at 16 days in storage.

  3. A study on the effect of P/E and PEG ratios on stock returns: Evidence from Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Seyyed Ali Lajevardi

    2014-07-01

    Full Text Available This paper studies the effect of the ratios of P/E and PEG on stock returns of the firms accepted on Tehran Stock Exchange. The study uses regression and Pearson Correlation Coefficient based on the performance of 138 firms over the period 2004- 2009 according to the Iranian calendar to investigate the effects of P/E and PEG on stock returns. The study also uses the models originally proposed by Chahin and Choudhry (2010 [Chahin, S., & Choudhry, T. (2010. Price to earnings, growth radio and value growth based strategies. Social Science Research Network, 19(4.] to discuss the strategies of investing on stocks. The results show that the ratio of P/E had more effect on stock returns than the ratio of PEG and stocks returns had a direct relationship with P/E and an inverse relationship with PEG. In addition, the returns of growth stock were more than value stock.

  4. Re-establishment of desiccation tolerance by PEG in germinated Arabidopsis thaliana seeds

    NARCIS (Netherlands)

    Maia de Oliveira, Julio; Dias Costa, Maria; Ligterink, Wilco; Hilhorst, Henk

    2015-01-01

    Mature seeds of Arabidopsis thaliana are desiccation tolerant, but they lose DT while progressing to germination. Yet, there is a small developmental window during which DT can be rescued by treatment with polyethylene glycol (PEG).

  5. China's Exchange Rate Policy : The Case Against Abandoning the Dollar PEG

    NARCIS (Netherlands)

    Laurenceson, J.; Qin, F.

    2005-01-01

    This paper critically evaluates the policy literature surrounding China's exchange rate regime.It first discusses several popularly raised contentions in relation to the dollar peg employed by China, which in fact are poorly grounded in evidence.These include notions that the RMB is clearly

  6. Comparison of effectiveness between cork-screw and peg-screw electrodes for transcranial motor evoked potential monitoring using the finite element method.

    Science.gov (United States)

    Tomio, Ryosuke; Akiyama, Takenori; Ohira, Takayuki; Yoshida, Kazunari

    2016-01-01

    Intraoperative monitoring of motor evoked potentials by transcranial electric stimulation is popular in neurosurgery for monitoring motor function preservation. Some authors have reported that the peg-screw electrodes screwed into the skull can more effectively conduct current to the brain compared to subdermal cork-screw electrodes screwed into the skin. The aim of this study was to investigate the influence of electrode design on transcranial motor evoked potential monitoring. We estimated differences in effectiveness between the cork-screw electrode, peg-screw electrode, and cortical electrode to produce electric fields in the brain. We used the finite element method to visualize electric fields in the brain generated by transcranial electric stimulation using realistic three-dimensional head models developed from T1-weighted images. Surfaces from five layers of the head were separated as accurately as possible. We created the "cork-screws model," "1 peg-screw model," "peg-screws model," and "cortical electrode model". Electric fields in the brain radially diffused from the brain surface at a maximum just below the electrodes in coronal sections. The coronal sections and surface views of the brain showed higher electric field distributions under the peg-screw compared to the cork-screw. An extremely high electric field was observed under cortical electrodes. Our main finding was that the intensity of electric fields in the brain are higher in the peg-screw model than the cork-screw model.

  7. Functional PEG-PAMAM-tetraphosphonate capped NaLnF₄ nanoparticles and their colloidal stability in phosphate buffer.

    Science.gov (United States)

    Zhao, Guangyao; Tong, Lemuel; Cao, Pengpeng; Nitz, Mark; Winnik, Mitchell A

    2014-06-17

    Developing surface coatings for NaLnF4 nanoparticles (NPs) that provide long-term stability in solutions containing competitive ions such as phosphate remains challenging. An amine-functional polyamidoamine tetraphosphonate (NH2-PAMAM-4P) as a multidentate ligand for these NPs has been synthesized and characterized as a ligand for the surface of NaGdF4 and NaTbF4 nanoparticles. A two-step ligand exchange protocol was developed for introduction of the NH2-PAMAM-4P ligand on oleate-capped NaLnF4 NPs. The NPs were first treated with methoxy-poly(ethylene glycol)-monophosphoric acid (M(n) = 750) in tetrahydrofuran. The mPEG750-OPO3-capped NPs were stable colloidal solutions in water, where they could be ligand-exchanged with NH2-PAMAM-4P. The surface amine groups on the NPs were available for derivatization to attach methoxy-PEG (M(n) = 2000) and biotin-terminated PEG (M(n) = 2000) chains. The surface coverage of ligands on the NPs was examined by thermal gravimetric analysis, and by a HABA analysis for biotin-containing NPs. Colloidal stability of the NPs was examined by dynamic light scattering. NaGdF4 and NaTbF4 NPs capped with mPEG2000-PAMAM-4P showed colloidal stability in DI water and in phosphate buffer (10 mM, pH 7.4). A direct comparison with NaTbF4 NPs capped with a mPEG2000-lysine-based tetradentate ligand that we reported previously (Langmuir 2012, 28, 12861-12870) showed that both ligands provided long-term stability in phosphate buffer, but that the lysine-based ligand provided better stability in phosphate-buffered saline.

  8. Effect of processing temperature on the bitumen/MDI-PEG reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Alfonso, M.J.; Partal, P.; Navarro, F.J.; Garcia-Morales, M. [Departamento de Ingenieria Quimica, Facultad de Ciencias Experimentales, Campus de ' El Carmen' , Universidad de Huelva, 21071, Huelva (Spain); Bordado, J.C.M. [Chemical and Biological Engineering Department, IBB, Instituto Superior Tecnico, Av. Rovisco Pais 1049-001 Lisbon (Portugal); Diogo, A.C. [Materials Engineering Department, Instituto Superior Tecnico, Av. Rovisco Pais 1049-001 Lisbon (Portugal)

    2009-04-15

    Reactive polymers are lately gaining acceptance to give added value to a residue of the crude oil refining process such as bitumen. The resulting material should display enhanced mechanical properties to be considered for advanced applications in construction. In the present paper, we report the effect of processing temperature on the reaction between bitumen compounds and an isocyanate-based reactive polymer, synthesized by reaction of polymeric MDI (4,4'-diphenylmethane diisocyanate) with a low molecular weight polyethylene-glycol (PEG). Rheokinetics experiments, viscosity measurements at 60 C, atomic force microscopy (AFM) characterization, thin layer chromatography (TLC-FID) analysis and thermogravimetric studies (TGA) were performed on the reactive polymer and on samples of MDI-PEG modified bitumen containing 2 wt.% of the polymer. Results showed the existence of an optimum processing temperature arisen as a consequence of opposite effects: microstructural availability for the formation of a polymer-bitumen network, reaction ability and polymer thermal degradation. Consequently, this study aims to serve as a guideline for the refining and asphalt industries facing the stage of selecting the optimum processing parameters. (author)

  9. The effect of gamma radiation on the structure of graphene oxide and graphene oxide functionalized with amino-PEG

    International Nuclear Information System (INIS)

    Soares, Jaqueline J.S.; Jacovone, Raynara M.S.; Santos, Paulo S.; Zaim, Márcio H.; Faria, Dalva L.A. de; Sakata, Solange K.; Universidade de Sao Paulo

    2017-01-01

    The functionalization of graphene oxide (GO) with polyethylene glycol (PEG) has been widely used in drug delivery systems. This nanocomposite exhibits excellent stability in the presence of high concentrations of salts and proteins and shows to be less toxic than its raw form in vitro and in vivo. However, it must be sterilized before use in the medical field and the gamma irradiation shows a promising option for this purpose. Sterilization by ionizing energy through gamma rays, generated by Cobalt-60 self-disintegration, consists in exposing the materials to short electromagnetic waves. The irradiation process provides substantial advantages when compared to thermal and chemical processes such as more precise control of the process, production of products with superior qualities, lower energy consumption and less environmental pollution. In this work the effect of gamma radiation on the structure of GO and GO functionalized com Amino-PEG (GO-PEG-NH_2) irradiated with different doses (15, 25, 35 and 50 kGy) and rate dose 7.31 kGy.h"-"1 was evaluated. The analyses were performed by Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The results showed that the methods for the synthesis of GO and GO-PEG-NH_2 was effective since there was confirmation of the surface oxidation of materials and functionalization with the PEG-NH_2 and the sterilization by gamma radiation does not caused any defects on materials. (author)

  10. The effect of gamma radiation on the structure of graphene oxide and graphene oxide functionalized with amino-PEG

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Jaqueline J.S.; Jacovone, Raynara M.S.; Santos, Paulo S.; Zaim, Márcio H.; Faria, Dalva L.A. de; Sakata, Solange K., E-mail: jaque.soares@ipen.br, E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Universidade de Sao Paulo (IQ/USP), SP (Brazil). Instituto de Química

    2017-07-01

    The functionalization of graphene oxide (GO) with polyethylene glycol (PEG) has been widely used in drug delivery systems. This nanocomposite exhibits excellent stability in the presence of high concentrations of salts and proteins and shows to be less toxic than its raw form in vitro and in vivo. However, it must be sterilized before use in the medical field and the gamma irradiation shows a promising option for this purpose. Sterilization by ionizing energy through gamma rays, generated by Cobalt-60 self-disintegration, consists in exposing the materials to short electromagnetic waves. The irradiation process provides substantial advantages when compared to thermal and chemical processes such as more precise control of the process, production of products with superior qualities, lower energy consumption and less environmental pollution. In this work the effect of gamma radiation on the structure of GO and GO functionalized com Amino-PEG (GO-PEG-NH{sub 2}) irradiated with different doses (15, 25, 35 and 50 kGy) and rate dose 7.31 kGy.h{sup -1} was evaluated. The analyses were performed by Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The results showed that the methods for the synthesis of GO and GO-PEG-NH{sub 2} was effective since there was confirmation of the surface oxidation of materials and functionalization with the PEG-NH{sub 2} and the sterilization by gamma radiation does not caused any defects on materials. (author)

  11. Aspartic acid-based modified PLGA-PEG nanoparticles for bone targeting: in vitro and in vivo evaluation.

    Science.gov (United States)

    Fu, Yin-Chih; Fu, Tzu-Fun; Wang, Hung-Jen; Lin, Che-Wei; Lee, Gang-Hui; Wu, Shun-Cheng; Wang, Chih-Kuang

    2014-11-01

    Nanoparticles (NP) that target bone tissue were developed using PLGA-PEG (poly(lactic-co-glycolic acid)-polyethylene glycol) diblock copolymers and bone-targeting moieties based on aspartic acid, (Asp)(n(1,3)). These NP are expected to enable the transport of hydrophobic drugs. The molecular structures were examined by (1)H NMR or identified using mass spectrometry and Fourier transform infrared (FT-IR) spectra. The NP were prepared using the water miscible solvent displacement method, and their size characteristics were evaluated using transmission electron microscopy (TEM) and dynamic light scattering. The bone targeting potential of the NP was evaluated in vitro using hydroxyapatite affinity assays and in vivo using fluorescent imaging in zebrafish and rats. It was confirmed that the average particle size of the NP was <200 nm and that the dendritic Asp3 moiety of the PLGA-PEG-Asp3 NP exhibited the best apatite mineral binding ability. Preliminary findings in vivo bone affinity assays in zebrafish and rats indicated that the PLGA-PEG-ASP3 NP may display increased bone-targeting efficiency compared with other PLGA-PEG-based NP that lack a dendritic Asp3 moiety. These NP may act as a delivery system for hydrophobic drugs, warranting further evaluation of the treatment of bone disease. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. Supercritical CO2-assisted preparation of ibuprofen loaded PEG-PVP complexes

    CSIR Research Space (South Africa)

    Labuschagne, Philip W

    2010-06-01

    Full Text Available Stoichiometric ratios of poly (ethylene glycol) (PEG, Mw = 400) with poly(vinylpyrrolidone) (PVP, Mw = ±3.1 x 104 & Mw = 1.25 x 106 Mw) were prepared from ethanol cast solutions and in supercritical CO2. The complex formation was studied via glass...

  13. Effect of Hydrophobic Chain Length on the Stability and Guest Exchange Behavior of Shell-Sheddable Micelles Formed by Disulfide-Linked Diblock Copolymers.

    Science.gov (United States)

    Fan, Haiyan; Li, Yixia; Yang, Jinxian; Ye, Xiaodong

    2017-10-19

    Reduction-responsive micelles hold enormous promise for application as drug carriers due to the fast drug release triggered by reducing conditions and high anticancer activity. However, the effect of hydrophobic chain length on the stability and guest exchange of reduction-responsive micelles, especially for the micelles formed by diblock copolymers containing single disulfide group, is not fully understood. Here, shell-sheddable micelles formed by a series of disulfide-linked copolymer poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-SS-PCL) containing the same chain length of PEG but different chain lengths of hydrophobic block PCL were prepared and well characterized. The influence of the chain length of hydrophobic PCL block on the stability and guest exchange of PEG-SS-PCL micelles was studied by the use of both dynamic laser light scattering (DLS) and fluorescence resonance energy transfer (FRET). The results show that longer PCL chains lead to a slower aggregation rate and guest exchange of micelles in the aqueous solutions containing 10 mM dithiothreitol (DTT). The cell uptake of the shell-sheddable PEG-SS-PCL micelles in vitro shows that the amount of internalization of dyes loaded in PEG-SS-PCL micelles increases with the chain length of hydrophobic PCL block investigated by flow cytometric analysis and confocal fluorescence microscopy.

  14. Intraperitoneal administration of high doses of polyethylene glycol (PEG) causes hepatic subcapsular necrosis and low-grade peritonitis with a rise in hepatic biomarkers

    International Nuclear Information System (INIS)

    Pellegrini, Giovanni; Starkey Lewis, Phil J.; Palmer, Luke; Hetzel, Udo; Goldring, Christopher E.; Park, B. Kevin; Kipar, Anja; Williams, Dominic P.

    2013-01-01

    Polyethylene glycols (PEGs) are commonly employed as excipients in preclinical studies and in vitro experiments to dissolve poorly hydrosoluble drugs. Their use is generally considered safe in both animals and humans; however, limited data is available concerning the safety of PEGs when administered parenterally. The results of our investigation demonstrate that PEG-400 can have an irritant effect on serosal surfaces and causes subcapsular hepatocellular necrosis in mice when administered intraperitoneally at a high dose (4 mL/kg). Accordingly, levels of serum biomarkers of liver injury need to be carefully interpreted in studies where PEG is administered intraperitoneally and always in association with the results of the histological assessment

  15. Lignocellulosic ethanol production by starch-base industrial yeast under PEG detoxification

    Science.gov (United States)

    Liu, Xiumei; Xu, Wenjuan; Mao, Liaoyuan; Zhang, Chao; Yan, Peifang; Xu, Zhanwei; Zhang, Z. Conrad

    2016-02-01

    Cellulosic ethanol production from lignocellulosic biomass offers a sustainable solution for transition from fossil based fuels to renewable alternatives. However, a few long-standing technical challenges remain to be addressed in the development of an economically viable fermentation process from lignocellulose. Such challenges include the needs to improve yeast tolerance to toxic inhibitory compounds and to achieve high fermentation efficiency with minimum detoxification steps after a simple biomass pretreatment. Here we report an in-situ detoxification strategy by PEG exo-protection of an industrial dry yeast (starch-base). The exo-protected yeast cells displayed remarkably boosted vitality with high tolerance to toxic inhibitory compounds, and with largely improved ethanol productivity from crude hydrolysate derived from a pretreated lignocellulose. The PEG chemical exo-protection makes the industrial S. cerevisiae yeast directly applicable for the production of cellulosic ethanol with substantially improved productivity and yield, without of the need to use genetically modified microorganisms.

  16. Comparison of cell uptake, biodistribution and tumor retention of folate-coated and PEG-coated gadolinium nanoparticles in tumor-bearing mice.

    Science.gov (United States)

    Oyewumi, Moses O; Yokel, Robert A; Jay, Michael; Coakley, Tricia; Mumper, Russell J

    2004-03-24

    The purpose of these studies was to compare the cell uptake, biodistribution and tumor retention of folate-coated and PEG-coated gadolinium (Gd) nanoparticles. Gd is a potential agent for neutron capture therapy (NCT) of tumors. Gd nanoparticles were engineered from oil-in-water microemulsion templates. To obtain folate-coated nanoparticles, a folate ligand [folic acid chemically linked to distearoylphosphatidylethanolamine (DSPE) via a PEG spacer MW 3350] was included in nanoparticle preparations. Similarly, control nanoparticles were coated with DSPE-PEG-MW 3350 (PEG-coated). Nanoparticles were characterized based on size, size distribution, morphology, biocompatibility and tumor cell uptake. In vivo studies were carried out in KB (human nasopharyngeal carcinoma) tumor-bearing athymic mice. Biodistribution and tumor retention studies were carried out at pre-determined time intervals after injection of nanoparticles (10 mg/kg). Gd nanoparticles did not aggregate platelets or activate neutrophils. The retention of nanoparticles in the blood 8, 16 and 24 h post-injection was 60%, 13% and 11% of the injected dose (ID), respectively. A maximum Gd tumor localization of 33+/-7 microg Gd/g was achieved. Both folate-coated and PEG-coated nanoparticles had comparable tumor accumulation. However, the cell uptake and tumor retention of folate-coated nanoparticles was significantly enhanced over PEG-coated nanoparticles. Thus, the benefits of folate ligand coating were to facilitate tumor cell internalization and retention of Gd-nanoparticles in the tumor tissue. The engineered nanoparticles may have potential in tumor-targeted delivery of Gd thereby enhancing the therapeutic success of NCT.

  17. Multifunctional PEG-carboxylate copolymer coated superparamagnetic iron oxide nanoparticles for biomedical application

    Science.gov (United States)

    Illés, Erzsébet; Szekeres, Márta; Tóth, Ildikó Y.; Szabó, Ákos; Iván, Béla; Turcu, Rodica; Vékás, Ladislau; Zupkó, István; Jaics, György; Tombácz, Etelka

    2018-04-01

    Biocompatible magnetite nanoparticles (MNPs) were prepared by post-coating the magnetic nanocores with a synthetic polymer designed specifically to shield the particles from non-specific interaction with cells. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers and acrylic acid (AA) small molecular monomers were chemically coupled by quasi-living atom transfer radical polymerization (ATRP) to a comb-like copolymer, P(PEGMA-co-AA) designated here as P(PEGMA-AA). The polymer contains pendant carboxylate moieties near the backbone and PEG side chains. It is able to bind spontaneously to MNPs; stabilize the particles electrostatically via the carboxylate moieties and sterically via the PEG moieties; provide high protein repellency via the structured PEG layer; and anchor bioactive proteins via peptide bond formation with the free carboxylate groups. The presence of the P(PEGMA-AA) coating was verified in XPS experiments. The electrosteric (i.e., combined electrostatic and steric) stabilization is efficient down to pH 4 (at 10 mM ionic strength). Static magnetization and AC susceptibility measurements showed that the P(PEGMA-AA)@MNPs are superparamagnetic with a saturation magnetization value of 55 emu/g and that both single core nanoparticles and multicore structures are present in the samples. The multicore components make our product well suited for magnetic hyperthermia applications (SAR values up to 17.44 W/g). In vitro biocompatibility, cell internalization, and magnetic hyperthermia studies demonstrate the excellent theranostic potential of our product.

  18. Enhanced mechanical properties of thermosensitive chitosan hydrogel by silk fibers for cartilage tissue engineering

    International Nuclear Information System (INIS)

    Mirahmadi, Fereshteh; Tafazzoli-Shadpour, Mohammad; Shokrgozar, Mohammad Ali; Bonakdar, Shahin

    2013-01-01

    Articular cartilage has limited repair capability following traumatic injuries and current methods of treatment remain inefficient. Reconstructing cartilage provides a new way for cartilage repair and natural polymers are often used as scaffold because of their biocompatibility and biofunctionality. In this study, we added degummed chopped silk fibers and electrospun silk fibers to the thermosensitive chitosan/glycerophosphate hydrogels to reinforce two hydrogel constructs which were used as scaffold for hyaline cartilage regeneration. The gelation temperature and gelation time of hydrogel were analyzed by the rheometer and vial tilting method. Mechanical characterization was measured by uniaxial compression, indentation and dynamic mechanical analysis assay. Chondrocytes were then harvested from the knee joint of the New Zealand white rabbits and cultured in constructs. The cell proliferation, viability, production of glycosaminoglycans and collagen type II were assessed. The results showed that mechanical properties of the hydrogel were significantly enhanced when a hybrid with two layers of electrospun silk fibers was made. The results of GAG and collagen type II in cell-seeded scaffolds indicate support of the chondrogenic phenotype for chondrocytes with a significant increase in degummed silk fiber–hydrogel composite for GAG content and in two-layer electrospun fiber–hydrogel composite for Col II. It was concluded that these two modified scaffolds could be employed for cartilage tissue engineering. - Highlights: • Chitosan hydrogel composites fabricated by two forms of silk fiber • Silk fibers provide structural support for the hydrogel matrix. • The mechanical properties of hydrogel significantly improved by associating with silk. • Production of GAG and collagen type II was demonstrated within the scaffolds

  19. Enhanced mechanical properties of thermosensitive chitosan hydrogel by silk fibers for cartilage tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Mirahmadi, Fereshteh [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Tafazzoli-Shadpour, Mohammad, E-mail: Tafazoli@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali, E-mail: mashokrgozar@pasteur.ac.ir [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Bonakdar, Shahin [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of)

    2013-12-01

    Articular cartilage has limited repair capability following traumatic injuries and current methods of treatment remain inefficient. Reconstructing cartilage provides a new way for cartilage repair and natural polymers are often used as scaffold because of their biocompatibility and biofunctionality. In this study, we added degummed chopped silk fibers and electrospun silk fibers to the thermosensitive chitosan/glycerophosphate hydrogels to reinforce two hydrogel constructs which were used as scaffold for hyaline cartilage regeneration. The gelation temperature and gelation time of hydrogel were analyzed by the rheometer and vial tilting method. Mechanical characterization was measured by uniaxial compression, indentation and dynamic mechanical analysis assay. Chondrocytes were then harvested from the knee joint of the New Zealand white rabbits and cultured in constructs. The cell proliferation, viability, production of glycosaminoglycans and collagen type II were assessed. The results showed that mechanical properties of the hydrogel were significantly enhanced when a hybrid with two layers of electrospun silk fibers was made. The results of GAG and collagen type II in cell-seeded scaffolds indicate support of the chondrogenic phenotype for chondrocytes with a significant increase in degummed silk fiber–hydrogel composite for GAG content and in two-layer electrospun fiber–hydrogel composite for Col II. It was concluded that these two modified scaffolds could be employed for cartilage tissue engineering. - Highlights: • Chitosan hydrogel composites fabricated by two forms of silk fiber • Silk fibers provide structural support for the hydrogel matrix. • The mechanical properties of hydrogel significantly improved by associating with silk. • Production of GAG and collagen type II was demonstrated within the scaffolds.

  20. Mechanical behaviour׳s evolution of a PLA-b-PEG-b-PLA triblock copolymer during hydrolytic degradation.

    Science.gov (United States)

    Breche, Q; Chagnon, G; Machado, G; Girard, E; Nottelet, B; Garric, X; Favier, D

    2016-07-01

    PLA-b-PEG-b-PLA is a biodegradable triblock copolymer that presents both the mechanical properties of PLA and the hydrophilicity of PEG. In this paper, physical and mechanical properties of PLA-b-PEG-b-PLA are studied during in vitro degradation. The degradation process leads to a mass loss, a decrease of number average molecular weight and an increase of dispersity index. Mechanical experiments are made in a specific experimental set-up designed to create an environment close to in vivo conditions. The viscoelastic behaviour of the material is studied during the degradation. Finally, the mechanical behaviour is modelled with a linear viscoelastic model. A degradation variable is defined and included in the model to describe the hydrolytic degradation. This variable is linked to physical parameters of the macromolecular polymer network. The model allows us to describe weak deformations but become less accurate for larger deformations. The abilities and limits of the model are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. PEG-albumin plasma expansion increases expression of MCP-1 evidencing increased circulatory wall shear stress: an experimental study.

    Directory of Open Access Journals (Sweden)

    C Makena Hightower

    Full Text Available Treatment of blood loss with plasma expanders lowers blood viscosity, increasing cardiac output. However, increased flow velocity by conventional plasma expanders does not compensate for decreased viscosity in maintaining vessel wall shear stress (WSS, decreasing endothelial nitric oxide (NO production. A new type of plasma expander using polyethylene glycol conjugate albumin (PEG-Alb causes supra-perfusion when used in extreme hemodilution and is effective in treating hemorrhagic shock, although it is minimally viscogenic. An acute 40% hemodilution/exchange-transfusion protocol was used to compare 4% PEG-Alb to Ringer's lactate, Dextran 70 kDa and 6% Hetastarch (670 kDa in unanesthetized CD-1 mice. Serum cytokine analysis showed that PEG-Alb elevates monocyte chemotactic protein-1 (MCP-1, a member of a small inducible gene family, as well as expression of MIP-1α, and MIP-2. MCP-1 is specific to increased WSS. Given the direct link between increased WSS and production of NO, the beneficial resuscitation effects due to PEG-Alb plasma expansion appear to be due to increased WSS through increased perfusion and blood flow rather than blood viscosity.

  2. Hepatitis C virus therapy with peg-interferon and ribavirin in Myanmar: A resource-constrained country.

    Science.gov (United States)

    Hlaing, Naomi Khaing Than; Banerjee, Debolina; Mitrani, Robert; Arker, Soe Htet; Win, Kyaw San; Tun, Nyan Lin; Thant, Zaw; Win, Khin Maung; Reddy, K Rajender

    2016-11-21

    To investigate peg-interferon (peg-IFN) and ribavirin (RBV) therapy in Myanmar and to predict sustained virologic response (SVR). This single-center, open-label, study was conducted in Myanmar between 2009 and 2014. A total of 288 patients infected with HCV genotypes 1, 2, 3 and 6 were treated with peg-IFN alpha-2a (180 μg/wk) or alpha-2b (50 to 100 μg as a weight-based dose) and RBV as a weight-based dose (15 mg/kg/d). Treatment duration was 48 wk for genotypes 1 and 6, 24 wk for genotype 2, and 24 or 48 wk for genotype 3 based on rapid virologic response (RVR). Those co-infected with hepatitis B received 48 wk of therapy. Overall, SVR was achieved for 82% of patients and the therapy was well tolerated. All patients achieved SVR at equivalent rates regardless of HCV genotype ( P = 0.314). Low fibrosis scores ( P 96% positive predictive value for achieving SVR. Treatment duration did not significantly impact the likelihood of achieving SVR for patients infected with genotype 3 HCV ( P = 0.371). The most common adverse events were fatigue (71%) and poor appetite (60%). Among patients with genotype 3 HCV, more patients in the 48-wk treatment group required erythropoietin than in the 24-wk treatment group (61.1% vs 49.2%). SVR rates were high with peg-IFN and RBV therapy in Myanmar. Fibrosis scores, baseline albumin, HCV RNA levels and RVR independently predicted SVR.

  3. Seed Germination Behaviors Of Some Aerobic Rice Cultivars Oryza Sativa L After Priming With Polyethylene Glycol-8000 Peg-8000

    Directory of Open Access Journals (Sweden)

    Elkheir H.A

    2015-08-01

    Full Text Available Seed Priming Is Famous Technique To Accelerate Seed Germination Behaviors. This Experiment Was Conducted To Study The Effect Of Polyethylene Glycol-8000 Peg-8000 As Priming Agent On Seed Germination Behavior Of Some Aerobic Rice Cultivars Oryza Sativa L. Experiment Was Carried Out By Using Two-Factor Three Aerobic Rice Cultivars And Peg With Four Replications Which Arranged In Factorial System Design And Conducted With Completely Randomized Design. The Factor Was Varieties Which Were Inpago 8 V1 Ir64 V2 And Situbagendit V3 Combine With 4 Levels Of Peg Concentrations 0100 And 200 Gl-1 And Control With No Treatment. Experiment Was Repeated 4 Times So Total Number Of Experimental Units Were 48. Germination Parameters Measured Were Germination Percentage Germination Index Days Of 50 Germination Seedling Fresh Weight Mg Seedling Shoot Fresh Weight And Root Fresh Weight Mg Seedling Dry Weigh Mg Seedling Shoot Dry Weight And Root Dry Weight Mg ShootRoot Ratio Seedling Length Cm Seedling Root Length Cm And Shoot Length Cm And Seed Vigor Index. The Results Indicated That Seed Priming Significantly Affected Germination Behaviors Compared With Control Depending Upon Varieties. The Highest Germination Was Obtained Under Laboratory And Greenhouse Condition By The Treatment Of Peg 200 G L-1 On The Situbagendit And Ir-64 Variety 90.25 And 93.33 Respectively Compared To Control In Inpago-8 In Both Laboratory 75.75 And Greenhouse 80 . As Implementation To Increase Seed And Seedling Vigor Of Rice It Is A Best Practice To Use Peg Priming With 200 Gl-1 Solutions Depend Upon Varietal Response And We Suggest That More Research About The Effect Of Peg As Seed Priming Techniques On Seed Germination Behavior Of Many Grain Crops Is Needed To Confirm The Methodology.

  4. Prolonged first-line PEG-asparaginase treatment in pediatric acute lymphoblastic leukemia in the NOPHO ALL2008 protocol-Pharmacokinetics and antibody formation

    DEFF Research Database (Denmark)

    Tram Henriksen, Louise; Gottschalk Højfeldt, Sofie; Schmiegelow, Kjeld

    2017-01-01

    BACKGROUND: As pegylated asparaginase is becoming the preferred first-line asparaginase preparation in the chemotherapy regimens of childhood acute lymphoblastic leukemia (ALL), there is a need to evaluate this treatment. METHODS: The aim of this study was to evaluate the pharmacokinetics...... of prolonged upfront biweekly PEG-asparaginase (where PEG is polyethylene glycol) treatment by measuring serum l-asparaginase activity and formation of anti-PEG-asparaginase antibodies. A total of 97 evaluable patients (1-17 years), diagnosed with ALL, and treated according to the NOPHO ALL2008 protocol (where...... NOPHO is Nordic Society of Paediatric Haematology and Oncology) were included. In the NOPHO ALL2008 protocol, patients are randomized to 8 or 15 doses of intramuscular PEG-asparaginase (Oncaspar(®) ) 1,000 IU/m²/dose, at 2-week or 6-week intervals with a total of 30-week treatment (Clinical trials...

  5. Thiol-PEG-carboxyl-stabilized Fe{sub 2}O{sub 3}/Au nanoparticles targeted to CD105: Synthesis, characterization and application in MR imaging of tumor angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Song; Gong, Mingfu; Zhang, Dong; Yang, Hua [Department of Radiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China); Gao, Fabao [Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041 (China); Zou, Liguang, E-mail: zlgxqyy@163.com [Department of Radiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037 (China)

    2014-07-15

    Objective: To detect tumor angiogenesis in tumor-bearing mice using thiol-PEG-carboxyl-stabilized Fe{sub 2}O{sub 3}/Au nanoparticles targeted to CD105 on magnetic resonance imaging (MRI). Methods: Fe{sub 2}O{sub 3}/Au nanoparticles (hybrids) were prepared by reducing Au{sup 3+} on the surface of Fe{sub 2}O{sub 3} nanoparticles. Hybrids were stabilized with thiol-PEG-carboxyl via the Au–S covalent bond, and further conjugated with anti-CD105 antibodies through amide linkages. Characteristics of the hybrid-PEG-CD105 nanoparticles were evaluated. Using these nanoparticles, the labeling specificity of human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. MRI T2*-weighted images were obtained at different time points after intravenous administration of the hybrid-PEG-CD105 nanoparticles in the tumor-bearing mice. After MR imaging, the breast cancer xenografts were immediately resected for immunohistochemistry staining and Prussian blue staining to measure the tumor microvessel density (MVD) and evaluate the labeling of blood microvessels by the hybrid-PEG-CD105 nanoparticles in vivo. Results: The mean diameter of the hybrid-PEG-CD105 nanoparticles was 56.6 ± 8.0 nm, as measured by transmission electron microscopy (TEM). Immune activity of the hybrid-PEG-CD105 nanoparticles was 53% of that of the anti-CD105 antibody, as detected by enzyme-linked immunosorbent assay (ELISA). The specific binding of HUVECs with the hybrid-PEG-CD105 nanoparticles was proved by immunostaining and Prussian blue staining in vitro. For breast cancer xenografts, the combination of the hybrid-PEG-CD105 nanoparticles with blood microvessels was detectable by MRI after 60 min administration of the contrast agent. The T2* relative signal intensity (SI{sub R}) was positively correlated with the tumor MVD (R{sup 2} = 0.8972). Conclusion: Anti-CD105 antibody-coupled, thiol-PEG-carboxyl-stabilized core–shell Fe{sub 2}O{sub 3}/Au nanoparticles can efficiently target CD105 expressed

  6. Enhanced mechanical properties of thermosensitive chitosan hydrogel by silk fibers for cartilage tissue engineering.

    Science.gov (United States)

    Mirahmadi, Fereshteh; Tafazzoli-Shadpour, Mohammad; Shokrgozar, Mohammad Ali; Bonakdar, Shahin

    2013-12-01

    Articular cartilage has limited repair capability following traumatic injuries and current methods of treatment remain inefficient. Reconstructing cartilage provides a new way for cartilage repair and natural polymers are often used as scaffold because of their biocompatibility and biofunctionality. In this study, we added degummed chopped silk fibers and electrospun silk fibers to the thermosensitive chitosan/glycerophosphate hydrogels to reinforce two hydrogel constructs which were used as scaffold for hyaline cartilage regeneration. The gelation temperature and gelation time of hydrogel were analyzed by the rheometer and vial tilting method. Mechanical characterization was measured by uniaxial compression, indentation and dynamic mechanical analysis assay. Chondrocytes were then harvested from the knee joint of the New Zealand white rabbits and cultured in constructs. The cell proliferation, viability, production of glycosaminoglycans and collagen type II were assessed. The results showed that mechanical properties of the hydrogel were significantly enhanced when a hybrid with two layers of electrospun silk fibers was made. The results of GAG and collagen type II in cell-seeded scaffolds indicate support of the chondrogenic phenotype for chondrocytes with a significant increase in degummed silk fiber-hydrogel composite for GAG content and in two-layer electrospun fiber-hydrogel composite for Col II. It was concluded that these two modified scaffolds could be employed for cartilage tissue engineering. © 2013.

  7. Details of the Classification of Symbiotic Stars: The Case of the Symbiotic Nova AG Peg

    Directory of Open Access Journals (Sweden)

    Tatarnikova A. A.

    2016-09-01

    Full Text Available We analyze archival and modern spectroscopic and photometric observations of the oldest known symbiotic nova AG Peg. Its new outburst (which began in 2015 June differs greatly from the first one (which occurred in the mid-1850s. Fast photometric evolution of the new outburst is similar to that of Z And-type outbursts. However, the SED of AG Peg during the 2015 outburst, as well as during the quiescence, can be fitted by a standard three-component model (cool component + hot component + nebula, which is not common for an Z And-type outburst.

  8. Complement activation cascade triggered by PEG-PL engineered nanomedicines and carbon nanotubes: The challenges ahead

    DEFF Research Database (Denmark)

    Moghimi, S.M.; Andersen, Alina Joukainen; Hashemi, S.H.

    2010-01-01

    reactions to certain PEG-PL engineered nanomedicines in both experimental animals and man. These reactions are classified as pseudoallergy and may be associated with cardiopulmonary disturbance and other related symptoms of anaphylaxis. Recent studies suggest that complement activation may be a contributing......, but not a rate limiting factor, in eliciting hypersensitivity reactions to such nanomedicines in sensitive individuals. This is rather surprising since PEGylated structures are generally assumed to suppress protein adsorption and blood opsonization events including complement. Here, we examine the molecular...... basis of complement activation by PEG-PL engineered nanomedicines and carbon nanotubes and discuss the challenges ahead....

  9. Effect of poly ethylene glycol on the mechanical and thermal properties of bioactive poly(ε-caprolactone) melt extrudates for pharmaceutical applications.

    Science.gov (United States)

    Douglas, P; Albadarin, Ahmad B; Sajjia, M; Mangwandi, Chirangano; Kuhs, Manuel; Collins, Maurice N; Walker, Gavin M

    2016-03-16

    This paper investigates the effects of polyethylene glycol (PEG), on the mechanical and thermal properties of nalidixic acid/poly ε-caprolactone (NA)/PCL blends prepared by hot melt extrusion. The blends were characterized by tensile and flexural analysis, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction. Results show that loading PEG in the PCL had a detrimental effect on the tensile strength and toughness of the blends, reducing them by 20-40%. The partial miscibility of the PCL-PEG system, causes an increase in Tg. While increases in the crystallinity is attributed to the plasticisation effect of PEG and the nucleation effect of NA. The average crystal size increased by 8% upon PEG addition. Experimental data indicated that the addition of NA caused loss of the tensile strength and toughness of PCL. Thermal analysis of the PCL showed that on addition of the thermally unstable NA, thermal degradation occurred early and was autocatalytic. However, the NA did benefit from the heat shielding provided by the PCL matrix resulting in more thermally stable NA particles. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Amphiphilic polymer based on fluoroalkyl and PEG side chains for fouling release coating

    Science.gov (United States)

    Cong, W. W.; Wang, K.; Yu, X. Y.; Zhang, H. Q.; Lv, Z.; Gui, T. J.

    2017-12-01

    Under static conditions, fouling release coating could not express good release property to marine organisms. Amphiphilic polymer with mixture of fluorinated monomer and short side group of polyethylene glycol (PEG) was synthesized. And also we studied the ability of amphiphilic polymer to influence the surface properties and how it controlled the adhesion of marine organisms to coated surfaces. By incorporating fluorinated monomer and PEG side chain into the polymer, the effect of incorporating both polar and non-polar groups on fouling-release coating could be studied. The dry surface was characterized by three-dimensional digital microscopy and scanning electron microscopy (SEM), and the morphology of the amphiphilic fouling release coating showed just like flaky petal. The amphiphilic polymer in fouling release coating tended to reconstruct in water, and the ability was examined by static contact angle, which was smaller than the PDMS (polydimethylsiloxane) fouling release coating. Also surface energy was calculated by three solvents, and surface energy of amphiphilic fouling release coating was higher than that of the PDMS fouling release coating. To understand more about its fouling release property, seawater exposure method was adopted in gulf of Qingdao port. Fewer diatoms Navicula were found in biofilm after using amphiphilic fouling release coating. In general, coating containing both PEG and fluorinated side chain possessed certain fouling release property.

  11. Efficient Transformation of Oil Palm Protoplasts by PEG-Mediated Transfection and DNA Microinjection

    Science.gov (United States)

    Masani, Mat Yunus Abdul; Noll, Gundula A.; Parveez, Ghulam Kadir Ahmad; Sambanthamurthi, Ravigadevi; Prüfer, Dirk

    2014-01-01

    Background Genetic engineering remains a major challenge in oil palm (Elaeis guineensis) because particle bombardment and Agrobacterium-mediated transformation are laborious and/or inefficient in this species, often producing chimeric plants and escapes. Protoplasts are beneficial as a starting material for genetic engineering because they are totipotent, and chimeras are avoided by regenerating transgenic plants from single cells. Novel approaches for the transformation of oil palm protoplasts could therefore offer a new and efficient strategy for the development of transgenic oil palm plants. Methodology/Principal Findings We recently achieved the regeneration of healthy and fertile oil palms from protoplasts. Therefore, we focused on the development of a reliable PEG-mediated transformation protocol for oil palm protoplasts by establishing and validating optimal heat shock conditions, concentrations of DNA, PEG and magnesium chloride, and the transfection procedure. We also investigated the transformation of oil palm protoplasts by DNA microinjection and successfully regenerated transgenic microcalli expressing green fluorescent protein as a visible marker to determine the efficiency of transformation. Conclusions/Significance We have established the first successful protocols for the transformation of oil palm protoplasts by PEG-mediated transfection and DNA microinjection. These novel protocols allow the rapid and efficient generation of non-chimeric transgenic callus and represent a significant milestone in the use of protoplasts as a starting material for the development of genetically-engineered oil palm plants. PMID:24821306

  12. PEG-induced osmotic stress in Mentha x piperita L.: Structural features and metabolic responses.

    Science.gov (United States)

    Búfalo, Jennifer; Rodrigues, Tatiane Maria; de Almeida, Luiz Fernando Rolim; Tozin, Luiz Ricardo Dos Santos; Marques, Marcia Ortiz Mayo; Boaro, Carmen Silvia Fernandes

    2016-08-01

    The present study investigated whether osmotic stress induced by the exposure of peppermint (Mentha x piperita L.) to moderate and severe stress for short periods of time changes the plant's physiological parameters, leaf anatomy and ultrastructure and essential oil. Plants were exposed to two levels of polyethyleneglycol (50 g L(-1) and 100 g L(-1) of PEG) in a hydroponic experiment. The plants exposed to 50 g L(-1) maintained metabolic functions similar to those of the control group (0 g L(-1)) without changes in gas exchange or structural characteristics. The increase in antioxidant enzyme activity reduced the presence of free radicals and protected membranes, including chloroplasts and mitochondria. In contrast, the osmotic stress caused by 100 g L(-1) of PEG inhibited leaf gas exchange, reduced the essential oil content and changed the oil composition, including a decrease in menthone and an increase in menthofuran. These plants also showed an increase in peroxidase activity, but this increase was not sufficient to decrease the lipid peroxidation level responsible for damaging the membranes of organelles. Morphological changes were correlated with the evaluated physiological features: plants exposed to 100 g L(-1) of PEG showed areas with collapsed cells, increases in mesophyll thickness and the area of the intercellular space, cuticle shrinkage, morphological changes in plastids, and lysis of mitochondria. In summary, our results revealed that PEG-induced osmotic stress in M. x piperita depends on the intensity level of the osmotic stress applied; severe osmotic stress changed the structural characteristics, caused damage at the cellular level, and reduced the essential oil content and quality. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: physiological responses.

    Science.gov (United States)

    Penella, Consuelo; Nebauer, Sergio G; Bautista, Alberto San; López-Galarza, Salvador; Calatayud, Ángeles

    2014-06-15

    Recent studies have shown that tolerance to abiotic stress, including water stress, is improved by grafting. In a previous work, we took advantage of the natural variability of Capsicum spp. and selected accessions tolerant and sensitive to water stress as rootstocks. The behavior of commercial cultivar 'Verset' seedlings grafted onto the selected rootstocks at two levels of water stress provoked by adding 3.5 and 7% PEG (polyethylene glycol) was examined over 14 days. The objective was to identify the physiological traits responsible for the tolerance provided by the rootstock in order to determine if the tolerance is based on the maintenance of the water relations under water stress or through the activation of protective mechanisms. To achieve this goal, various physiological parameters were measured, including: water relations; proline accumulation; gas exchange; chlorophyll fluorescence; nitrate reductase activity; and antioxidant capacity. Our results indicate that the effect of water stress on the measured parameters depends on the duration and intensity of the stress level, as well as the rootstock used. Under control conditions (0% PEG) all plant combinations showed similar values for all measured parameters. In general terms, PEG provoked a strong decrease in the gas exchange parameters in the cultivar grafted onto the sensitive accessions, as also observed in the ungrafted plants. This effect was related to lower relative water content in the plants, provoked by an inefficient osmotic adjustment that was dependent on reduced proline accumulation. At the end of the experiment, chronic photoinhibition was observed in these plants. However, the plants grafted onto the tolerant rootstocks, despite the reduction in photosynthetic rate, maintained the protective capacity of the photosynthetic machinery mediated by osmotic adjustment (based on higher proline content). In addition, water stress limited uptake and further NO3(-) transfer to the leaves. Increased

  14. Algometry with a clothes peg compared to an electronic pressure algometer: a randomized cross-sectional study in pain patients.

    Science.gov (United States)

    Egloff, Niklaus; Klingler, Nicole; von Känel, Roland; Cámara, Rafael J A; Curatolo, Michele; Wegmann, Barbara; Marti, Elizabeth; Ferrari, Marie-Louise Gander

    2011-07-25

    Hypersensitivity of the central nervous system is widely present in pain patients and recognized as one of the determinants of chronic pain and disability. Electronic pressure algometry is often used to explore aspects of central hypersensitivity. We hypothesized that a simple pain provocation test with a clothes peg provides information on pain sensitivity that compares meaningfully to that obtained by a well-established electronic pressure algometer. "Clinically meaningful" was defined as a medium (r = 0.3-0.5) or high (r > 0.5) correlation coefficient according to Cohen's conventions. We tested 157 in-patients with different pain types. A calibrated clothes peg was applied for 10 seconds and patients rated the pain intensity on a 0 to 10 numerical rating scale. Pressure pain detection threshold (PPdt) and pressure pain tolerance threshold (PPtt) were measured with a standard electronic algometer. Both methods were performed on both middle fingers and ear lobes. In a subgroup of 47 patients repeatability (test-retest reliability) was calculated. Clothes peg values correlated with PPdt values for finger testing with r = -0.54 and for earlobe testing with r = -0.55 (all p-values testing with r = -0.55 (p Test-retest reliability (repeatability) showed equally stable results for clothes peg algometry and the electronic algometer (all r-values > 0.89, all p-values pain sensitivity provided by a calibrated clothes peg and an established algometer correlate at a clinically meaningful level.

  15. Smart pH- and reduction-dual-responsive folate-PEG-coated polymeric lipid vesicles for tumor-triggered targeted drug delivery

    Science.gov (United States)

    Wang, Sheng; Wang, Hanjie; Liu, Zhongyun; Wang, Liangliang; Wang, Xiaomin; Su, Lin; Chang, Jin

    2014-06-01

    To improve their therapeutic index, designed nanocarriers should preferentially accumulate in tumor tissues and then rapidly enter tumor cells to release the encapsulated drugs in a triggered manner. In this article, a new kind of a smart pH- and reduction-dual-responsive drug delivery system based on folate-PEG-coated polymeric lipid vesicles (FPPLVs) formed from amphiphilic dextran derivatives was designed and prepared successfully. PEG chains with pH-sensitive hydrazone bonds, stearyl alcohol (SA) chains with reduction-sensitive disulfide bonds and folate were connected to a dextran main chain. The newly developed FPPLVs had a nano-sized structure (~50 nm) with a PEG coating. The in vitro DOX release profiles showed that the FPPLVs achieved a triggered drug release in response to acidic pH and reducing environments due to the cleavage of hydrazone bonds and disulfide bonds. It has also been demonstrated by an in vitro cellular uptake study that the FPPLVs lose their PEG coating as well as expose the folate in acidic conditions, which allows them to efficiently enter tumor cells through ligand-receptor interactions. In vitro cytotoxicity measurements also confirmed that FPPLVs exhibited pronounced antitumor activity against HeLa cells. These results suggest that FPPLVs are promising carriers for smart antitumor drug delivery applications.To improve their therapeutic index, designed nanocarriers should preferentially accumulate in tumor tissues and then rapidly enter tumor cells to release the encapsulated drugs in a triggered manner. In this article, a new kind of a smart pH- and reduction-dual-responsive drug delivery system based on folate-PEG-coated polymeric lipid vesicles (FPPLVs) formed from amphiphilic dextran derivatives was designed and prepared successfully. PEG chains with pH-sensitive hydrazone bonds, stearyl alcohol (SA) chains with reduction-sensitive disulfide bonds and folate were connected to a dextran main chain. The newly developed FPPLVs had a

  16. Shape-memory properties of magnetically active triple-shape nanocomposites based on a grafted polymer network with two crystallizable switching segments

    Directory of Open Access Journals (Sweden)

    A. Lendlein

    2012-01-01

    Full Text Available Thermo-sensitive shape-memory polymers (SMP, which are capable of memorizing two or more different shapes, have generated significant research and technological interest. A triple-shape effect (TSE of SMP can be activated e.g. by increasing the environmental temperature (Tenv, whereby two switching temperatures (Tsw have to be exceeded to enable the subsequent shape changes from shape (A to shape (B and finally the original shape (C. In this work, we explored the thermally and magnetically initiated shape-memory properties of triple-shape nanocomposites with various compositions and particle contents using different shape-memory creation procedures (SMCP. The nanocomposites were prepared by the incorporation of magnetite nanoparticles into a multiphase polymer network matrix with grafted polymer network architecture containing crystallizable poly(ethylene glycol (PEG side chains and poly(ε-caprolactone (PCL crosslinks named CLEGC. Excellent triple-shape properties were achieved for nanocomposites with high PEG weight fraction when two-step programming procedures were applied. In contrast, single-step programming resulted in dual-shape properties for all investigated materials as here the temporary shape (A was predominantly fixed by PCL crystallites.

  17. Intelligently targeted drug delivery and enhanced antitumor effect by gelatinase-responsive nanoparticles.

    Directory of Open Access Journals (Sweden)

    Rutian Li

    Full Text Available AIMS: The matrix metalloproteinase (MMP 2/9, also known as collagenases IV and gelatinases A/B, play a key role in cancer invasion and metastasis. However, the clinical trials of the MMP inhibitors (MMPIs ended up with disappointing results. In this paper, we synthesized a gelatinase-responsive copolymer (mPEG-PCL by inserting a gelatinase cleavable peptide (PVGLIG between mPEG and PCL blocks of mPEG-PCL for anticancer drug delivery to make use of MMP2/9 as an intelligent target for drug delivery. MATERIALS AND METHODS: mPEG-pep-PCL copolymer was synthesized via ring-opening copolymerization and double-amidation. To evaluate whether Nanoparticles (NPs prepared from this copolymer are superior to NPs prepared from mPEG-PCL, NPs prepared from mPEG-PCL copolymer were used as positive control. Docetaxel-loading NPs using mPEG-pep-PCL and mPEG-PCL were prepared by nano-precipitation method, mentioned as Gel-NPs and Con-NPs, respectively. The morphologic changes of the NPs after treatment with gelatinases were observed macroscopically by spectrophotometer and microscopically by transmission electron microscopy (TEM and atomic force microscopy (AFM. The cellular uptake amount and cytotoxicity of Gel-NPs and Con-NPs, respectively, in cell lines with different levels of gelatinase expression were studied. Moreover, the cytotoxicity study on the primary cancer cells isolated from pericardial fluids from a patient with late-stage lung cancer was conducted. RESULTS: The Gel-NPs aggregated in response to gelatinases, which was confirmed macroscopically and microscopically. The cellular uptake amount of Gel-NPs was correlated with the level of gelatinases. The in vitro antitumor effect of Gel-NPs was also correlated with the level of gelatinases and was superior to Taxotere (commercially available docetaxel as well as the Con-NPs. The cytotoxicity study on the primary lung cancer cells also confirmed the effectiveness of Gel-NPs. CONCLUSION: The results in

  18. PEG capped CaS nanoparticles synthesized by wet chemical co-precipitation method

    Science.gov (United States)

    Rekha, S.; Anila, E. I.

    2018-04-01

    Calcium sulfide (CaS) nanoparticles capped with polyethyleneglycol (PEG) were synthesized using wet chemical co-precipitation method. The structural and optical properties of the prepared sample were studied by X-ray diffractogram (XRD), transmission electron microscopy (TEM), diffuse reflectance spectrum (DRS) and photoluminescence (PL) spectrum. The structure of CaS nanoparticles is cubic as demonstrated by the X-ray powder diffraction (XRD) and selected area electron diffraction (SAED) analysis. TEMimage revealed the spherical morphology of the particles with diameter in the range 15-20 nm. The optical band gap of the prepared sample was determined from the DRS and its value was found to be 4.1 eV. The PL studies showed that the relative intensity of the PEG capped CaS nanoparticles was higher than that of uncapped CaS nanoparticles. The presence of various functional groups in the capped samples were examined by Fourier Transform Infrared (FTIR) spectroscopy.

  19. Bypassing non-adherence via PEG in a critically ill HIV-1-infected patient.

    Science.gov (United States)

    Leipe, J; Hueber, A J; Rech, J; Harrer, T

    2008-08-01

    This case study describes a 44-year-old, chronically non-adherent, HIV-infected male with relapsing, life threatening toxoplasmic encephalitis (TE) and other recurring opportunistic infections. Non-adherence resulted in critical illness, suppressed CD4 lymphocyte count and elevated viral load. In order to bypass the patient's complete psychological aversion to taking medication, and after exhausting various psychological interventions, a percutaneous endoscopic gastronomy (PEG) tube was inserted for delivery of indispensable medication. During the 15-month follow-up the patient was adherent, exhibiting a consistently undetectable viral load, high CD4 count and a remission of the opportunistic infections. This is an interesting case study demonstrating life-saving and long-term benefit of PEG in an exceptional setting, which has implications for future research and treatment of non-adherent HIV-infected patients.

  20. Effect of MWCNT Filler on Properties and Flux of Chitosan/ PEG based Nanocomposites Membranes

    Directory of Open Access Journals (Sweden)

    Khoerunnisa Fitri

    2018-01-01

    Full Text Available Biopolymer are expected to be environmentally compatible and to have great potential application as membranes material. The chitosan-poly (ethylene glycol/PEG based composite membranes was successfully synthesized via inversed phase method. The effect of multiwalled carbon nanotubes (MWCNT as nanofiller on properties and performances of composite membranes were intensively evaluated. The membrane was prepared by mixing of chitosan and PEG solutions at the same composition ratio while MWCNT amount in the mixture was varied. The synthesized membrane was characterized by means of FTIR spectroscopy, scanning electron microscopy (SEM, contact angle, and tensile strength measurement. The performance of composite membrane on filtration was evaluated in term of flux (permeability and rejection (rejection tests. The results showed that the optimum volume ratio of composite membrane solution was found at 30:10:7.5 for chitosan/ PEG/ MWCNT, respectively, as indicated by the largest flux. Insertion of MWCNT nanofiller notably enhanced hydrophilicity, porosity, and mechanical properties of composites membranes that are confirmed by contact angle, SEM images and elongation forces value, respectively. The MWCNT nanofiller remarkably increased both of flux and rejection of composite membranes up to 60 Lm2h-1 and 96%, respectively. The remarkable enhancement of composite membrane performance is attributed to the effective interaction of MWCNT with polymeric matrix.

  1. Development of a behaviour change communication tool for medical students: the 'Tent Pegs' booklet.

    Science.gov (United States)

    Chisholm, Anna; Hart, Jo; Mann, Karen; Peters, Sarah

    2014-01-01

    To describe the development and validation of a behaviour change communication tool for medical students. Behaviour change techniques (BCTs) were identified within the literature and used to inform a communication tool to support medical students in discussing health-related behaviour change with patients. BCTs were organized into an accessible format for medical students (the 'Tent Pegs' booklet) and validated using discriminant content validity methods with 11 expert judges. One-sample t-tests showed that judges reliably mapped BCTs onto six of the seven Tent Pegs domains (confidence rating means ranged from 4.0 to 5.1 out of 10, all p≤0.002). Only BCTs within the 'empowering people to change' domain were not significantly different from the value zero (mean confidence rating=1.2, p>0.05); these BCTs were most frequently allocated to the 'addressing thoughts and emotions' domain instead. BCTs within the Tent Pegs booklet are reliably allocated to corresponding behaviour change domains with the exception of those within the 'empowering people to change' domain. The existing evidence-base on BCTs can be used to directly inform development of a communication tool to support medical students facilitate health behaviour change with patients. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

  2. Treatment of faecal impaction with polyethelene glycol plus electrolytes (PGE + E) followed by a double-blind comparison of PEG + E versus lactulose as maintenance therapy.

    Science.gov (United States)

    Candy, David C A; Edwards, Diane; Geraint, Mike

    2006-07-01

    To assess the efficacy of polyethylene glycol 3350 plus electrolytes (PEG + E; Movicol) as oral monotherapy in the treatment of faecal impaction in children, and to compare PEG + E with lactulose as maintenance therapy in a randomised trial. An initial open-label study of PEG + E in the inpatient treatment of faecal impaction (phase 1), followed by a randomised, double-blind comparison between PEG + E and lactulose for maintenance treatment of constipation over a 3-month period (phase 2) in children aged 2 to 11 years with a clinical diagnosis of faecal impaction. Disimpaction on PEG + E was achieved in 58 (92%) of 63 of children (89% of 2-4 year olds and 94% of 5-11 year olds) without additional interventions. A maximum dose of 4 sachets (for 2-4 year olds) or 6 sachets (for 5-11 year olds) was required; median time to disimpaction was 6 days (range, 3-7 days). Seven children (23%) reimpacted whilst taking lactulose, whereas no children reimpacted while taking PEG + E (P = 0.011). The total incidence rate of adverse events seen was higher in the lactulose group (83%) than in the PEG + E group (64%). PEG + E is safe and highly effective in the management of childhood constipation. It allows a single orally administered laxative to be used for disimpaction without recourse to invasive interventions. It is significantly more effective than lactulose as maintenance therapy, both in efficacy in treating constipation and efficacy in preventing the recurrence of faecal impaction.

  3. Cellularized cylindrical fiber/hydrogel composites for ligament tissue engineering.

    Science.gov (United States)

    Thayer, Patrick S; Dimling, Anna F; Plessl, Daniel S; Hahn, Mariah R; Guelcher, Scott A; Dahlgren, Linda A; Goldstein, Aaron S

    2014-01-13

    Electrospun meshes suffer from poor cell infiltration and limited thickness, which restrict their use to thin tissue applications. Herein, we demonstrate two complementary processes to overcome these limitations and achieve elastomeric composites that may be suitable for ligament repair. First, C3H10T1/2 mesenchymal stem cells were incorporated into electrospun meshes using a hybrid electrospinning/electrospraying process. Second, electrospun meshes were rolled and formed into composites with an interpenetrating polyethylene glycol (PEG) hydrogel network. Stiffer composites were formed from poly(lactic-co-glycolic acid) (PLGA) meshes, while softer and more elastic composites were formed from poly(ester-urethane urea) (PEUUR) meshes. As-spun PLGA and PEUUR rolled meshes had tensile moduli of 19.2 ± 1.9 and 0.86 ± 0.34 MPa, respectively, which changed to 11.6 ± 4.8 and 1.05 ± 0.39 MPa with the incorporation of a PEG hydrogel phase. In addition, cyclic tensile testing indicated that PEUUR-based composites deformed elastically to at least 10%. Finally, C3H10T1/2 cells incorporated into electrospun meshes survived the addition of the PEG phase and remained viable for up to 5 days. These results indicate that the fabricated cellularized composites are support cyclic mechanical conditioning, and have potential application in ligament repair.

  4. Poly(ethylene glycol-block-poly(ε-caprolactone– and phospholipid-based stealth nanoparticles with enhanced therapeutic efficacy on murine breast cancer by improved intracellular drug delivery

    Directory of Open Access Journals (Sweden)

    He XD

    2015-03-01

    Full Text Available Xiaodan He,1 Li Li,2 Hong Su,1 Dinglun Zhou,3 Hongmei Song,4 Ling Wang,1 Xuehua Jiang1 1West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 3West China School of Public Health, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 4HitGen Ltd., Chengdu, Sichuan, People’s Republic of China Background: Effective anticancer drug delivery to the tumor site without rapid body clearance is a prerequisite for successful chemotherapy. 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine-N-(methoxy[polyethyleneglycol]-2000 (DSPE-PEG2000 has been widely used in the preparation of stealth liposomes. Although PEG chains can efficiently preserve liposomes from rapid clearance by the reticuloendothelial system (RES, its application has been hindered by poor cellular uptake and unsatisfactory therapeutic effect.Methods: To address the dilemma, we presented a facile approach to fabricate novel stealth nanoparticles generated by poly(ethylene glycol-block-poly(ε-caprolactone (PEG-b-PCL, soybean phosphatidylcholine (SPC, and cholesterol, namely LPPs (L represented lipid and PP represented PEG-b-PCL, for the delivery of anticancer drug paclitaxel (PTX. LPPs were prepared using the thin film hydration method. Two PEG-b-PCL polymers with different molecular weights (MW; PEG2000-b-PCL2000, MW: 4,000 Da and PEG5000-b-PCL5000, MW: 10,000 Da were used to fabricate stealth nanoparticles. Conventional PEGylated liposome (LDP2000, L represented lipid and DP2000 represented DSPE-PEG2000 composed of SPC, cholesterol, and DSPE-PEG2000 was used as the control. The physical properties, cellular uptake, endocytosis pathway, cytotoxicity, pharmacokinetics, tumor accumulation, and anticancer efficacy of free PTX, PTX-loaded LPPs, and LDP2000 were systemically investigated after injection into 4T1

  5. Scolicidal and apoptotic activities of albendazole sulfoxide and albendazole sulfoxide-loaded PLGA-PEG as a novel nanopolymeric particle against Echinococcus granulosus protoscoleces.

    Science.gov (United States)

    Naseri, Marziyeh; Akbarzadeh, Abolfazl; Spotin, Adel; Akbari, Nagibeh Asl Rahnemaii; Mahami-Oskouei, Mahmoud; Ahmadpour, Ehsan

    2016-12-01

    Treatment failures of human cystic echinococcosis (CE) with albendazole (ABZ) have attributed to its low solubility and poor drug absorption rate, resulting in low drug level in plasma. The scolicidal effects of ABZ-loaded liposome nanoparticles have recently evaluated; however, these particles have several challenges due to their low encapsulated load. This investigation was designed to evaluate and compare in vitro apoptotic activities of ABZ sulfoxide (ABZs) and ABZs-loaded poly(lactic-co-glycolic acid) (PLGA)-PEG against protoscoleces (PSCs). ABZs-loaded PLGA-PEG was prepared by a double-emulsion method (W1/O/W2). Various concentrations of ABZs and ABZs-loaded PLGA-PEG (50, 100, 150, and 200 μg/ml) were experimentally tested against PSC of CE at different exposure times (5, 10, 20, 30, and 60 min). ABZs-loaded PLGA-PEG at concentrations of 150 and 200 μg/ml was able to act at a 100 % scolicidal rate in all exposure times (5 to 60 min), while ABZs at a concentration of 200 μg/ml demonstrated 94, 100, and 100 % mortality rates following 20, 30, and 60 min of exposure times, respectively. The messenger RNA (mRNA) expression of caspase-3 was assessed by semi-quantitative RT-PCR after 15 h of exposure. Caspase-3 mRNA expression was higher in both PSC treated with ABZs and PSC treated with ABZs-loaded PLGA-PEG than that in control groups (P  0.05). DNA fragmentation assay and ultrastructural changes revealed that ABZs and ABZs-loaded PLGA-PEG induced the apoptosis of PSC by activation of caspase-3. The higher permeability and scolicidal rate of ABZs-loaded PLGA-PEG can be addressed as an effectual alternative strategy to improve the treatment of human CE.

  6. Decontamination of skin exposed to nanocarriers using an absorbent textile material and PEG-12 dimethicone

    International Nuclear Information System (INIS)

    Lademann, J; Richter, H; Knorr, F; Baier, G; Landfester, K; Frazier, L; Gefeller, H; Wunderlich, U; Gross, I; Rühl, E

    2014-01-01

    The removal of noxious particulate contaminants such as pollutants derived from particle-to-gas conversions from exposed skin is essential to avoid the permeation of potentially harmful substances into deeper skin layers via the stratum corneum or the skin appendages and their dispersion throughout the circulatory system. This study is aimed at evaluating the efficacy of using the silicone glycol polymer PEG-12 dimethicone and an absorbent textile material to remove fluorescing hydroxyethyl starch nanocapsules implemented as model contaminants from exposed porcine ear skin. Using laser scanning microscopy, it could be shown that while the application and subsequent removal of the absorbent textile material alone did not result in sufficient decontamination, the combined application with PEG-12 dimethicone almost completely eliminated the nanocapsules from the surface of the skin. By acting as a wetting agent, PEG-12 dimethicone enabled the transfer of the nanocapsules into a liquid phase which was taken up by the absorbent textile material. Only traces of fluorescence remained detectable in several skin furrows and follicular orifices, suggesting that the repeated implementation of the procedure may be necessary to achieve total skin surface decontamination. (letter)

  7. Drug-conjugated PLA-PEG-PLA copolymers: a novel approach for controlled delivery of hydrophilic drugs by micelle formation.

    Science.gov (United States)

    Danafar, H; Rostamizadeh, K; Davaran, S; Hamidi, M

    2017-12-01

    A conjugate of the antihypertensive drug, lisinopril, with triblock poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA) copolymer was synthesized by the reaction of PLA-PEG-PLA copolymer with lisinopril in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine. The conjugated copolymer was characterized in vitro by hydrogen nuclear magnetic resonance (HNMR), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) techniques. Then, the lisinopril conjugated PLA-PEG-PLA were self-assembled into micelles in aqueous solution. The resulting micelles were characterized further by various techniques such as dynamic light scattering (DLS) and atomic force microscopy (AFM). The results revealed that the micelles formed by the lisinopril-conjugated PLA-PEG-PLA have spherical structure with the average size of 162 nm. The release behavior of conjugated copolymer, micelles and micelles physically loaded by lisinopril were compared in different media. In vitro release study showed that in contrast to physically loaded micelles, the release rate of micelles consisted of the conjugated copolymer was dependent on pH of media where it was higher at lower pH compared to the neutral medium. Another feature of the conjugated micelles was their more sustained release profile compared to the lisinopril-conjugated copolymer and physically loaded micelles.

  8. Extremely stretchable thermosensitive hydrogels by introducing slide-ring polyrotaxane cross-linkers and ionic groups into the polymer network

    Science.gov (United States)

    Bin Imran, Abu; Esaki, Kenta; Gotoh, Hiroaki; Seki, Takahiro; Ito, Kohzo; Sakai, Yasuhiro; Takeoka, Yukikazu

    2014-01-01

    Stimuli-sensitive hydrogels changing their volumes and shapes in response to various stimulations have potential applications in multiple fields. However, these hydrogels have not yet been commercialized due to some problems that need to be overcome. One of the most significant problems is that conventional stimuli-sensitive hydrogels are usually brittle. Here we prepare extremely stretchable thermosensitive hydrogels with good toughness by using polyrotaxane derivatives composed of α-cyclodextrin and polyethylene glycol as cross-linkers and introducing ionic groups into the polymer network. The ionic groups help the polyrotaxane cross-linkers to become well extended in the polymer network. The resulting hydrogels are surprisingly stretchable and tough because the cross-linked α-cyclodextrin molecules can move along the polyethylene glycol chains. In addition, the polyrotaxane cross-linkers can be used with a variety of vinyl monomers; the mechanical properties of the wide variety of polymer gels can be improved by using these cross-linkers. PMID:25296246

  9. Structural measurements and cell line studies of the copper-PEG-Rifampicin complex against Mycobacterium tuberculosis.

    Science.gov (United States)

    Manning, Thomas; Mikula, Rachel; Wylie, Greg; Phillips, Dennis; Jarvis, Jackie; Zhang, Fengli

    2015-02-01

    The bacterium responsible for tuberculosis is increasing its resistance to antibiotics resulting in new multidrug-resistant Mycobacterium tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB). In this study, several analytical techniques including NMR, FT-ICR, MALDI-MS, LC-MS and UV/Vis are used to study the copper-Rifampicin-Polyethylene glycol (PEG-3350) complex. The copper (II) cation is a carrier for the antibiotic Rifampicin as well as nutrients for the bacterium. The NIH-NIAID cell line containing several Tb strains (including antibiotic resistant strains) is tested against seven copper-PEG-RIF complex variations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. In vitro/vivo drug release and anti-diabetic cardiomyopathy properties of curcumin/PBLG-PEG-PBLG nanoparticles.

    Science.gov (United States)

    Tong, Fei; Chai, Rongkui; Jiang, Haiying; Dong, Bo

    2018-01-01

    The objective of this study was to survey the therapeutic function of curcumin-encapsulated poly(gamma-benzyl l-glutamate)-poly(ethylene glycol)-poly(gammabenzyl l-glutamate) (PBLG-PEG-PBLG) (P) on diabetic cardiomyopathy (DCM) via cross regulation effect of calcium-sensing receptor (CaSR) and endogenous cystathionine-γ-lyase (CSE)/hydrogen sulfide (H 2 S). Diabetic rats were preconditioned with 20 mg/kg curcumin or curcumin/P complex continuously for 8 weeks. The blood and myocardiums were collected, the level of serum H 2 S was observed, and the [Ca 2+ ] i content was measured in myocardial cells, and hematoxylin-eosin, CaSR, CSE, and calmodulin (CaM) expression were detected. Both curcumin and curcumin/P pretreatment alleviated pathological morphological damage of myocardium, increased H 2 S and [Ca 2+ ] i levels, and upregulated the expression of CaSR, CSE, and CaM as compared to DCM group, while curcumin/P remarkably augmented this effect. PBLG-PEG-PBLG could improve water-solubility and bioactivity of curcumin and curcumin/PBLG-PEG-PBLG significantly alleviated diabetic cardiomyopathy.

  11. Influence of solubilizer PEG-40 hydrogenated castor oil on carbopol gels’ structural-mechanical properties

    Directory of Open Access Journals (Sweden)

    Ye. V. Gladukh

    2017-12-01

    Full Text Available Rheological properties affect all stages of the drug development – from development to production, the characteristics of the final products and stability. A lot of substances have complex rheological properties; their viscosity and elasticity can vary depending on conditions acting from the outside, such as stress, deformation, time factor and temperature. Concentration, stability and composition also significantly affect the rheological properties of drugs. One of the current trends in modern pharmacy is the development of drugs in the form of gels. The rheological properties of gels are significantly influenced by surface-active substances, stabilizers, solubilizers, stabilizing their structure. A special group of stabilizers are hydrogenated vegetable oils and their compounds with polymers, which have the ability to structure formation in interphase layers and in the volume of phases. For this purpose, PEG-40 hydrogenated castor oil is widely used. The aim of this work is to study the effect of hydrogenated castor oil, used as an emulsifier, solubilizer, viscosity modifier and solvent in the technology of semisolid dosage forms, on the structural and mechanical properties of carbopol gels. Materials and methods. 1% gel carbopol with additives PEG-40 hydrogenated castor oil in the concentration range from 1 to 5 % was investigated as experimental samples of the gel base. A 10 % propylene glycol additive was used as humectant and plasticizer. Structural and mechanical studies were carried out using a rotational viscometer «RheolabQC», Anton Paar (Austria with coaxial cylinders CCC27/SS. The graphs of the gels were automatically plotted using the computer program. Results. Analysis of the rheological parameters of the carbopol with PEG-40 hydrogenated castor oil gel base shows that the solubilizer has an active influence on the structural and mechanical properties of the base. Addition of PEG-40 GMM to the carbopol gel increases the yield

  12. PEG/SiO2–Al2O3 hybrid form-stable phase change materials with enhanced thermal conductivity

    International Nuclear Information System (INIS)

    Tang, Bingtao; Wu, Cheng; Qiu, Meige; Zhang, Xiwen; Zhang, Shufen

    2014-01-01

    The thermal conductivity of form-stable PEG/SiO 2 phase change material (PCM) was enhanced by in situ doping of Al 2 O 3 using an ultrasound-assisted sol–gel method. Fourier transform infrared spectroscopy (FT-IR) was used to characterize the structure, and the crystal performance was characterized by the X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA) were used to determine the thermal properties. The phase change enthalpy of PEG/SiO 2 –Al 2 O 3 reached 124 J g −1 , and thermal conductivity improved by 12.8% for 3.3 wt% Al 2 O 3 in the PCM compared with PEG/SiO 2 . The hybrid PCM has excellent thermal stability and form-stable effects. - Highlights: • The PEG/SiO 2 –Al 2 O 3 hybrid form-stable phase change material (PCM) was obtained through the sol–gel method. • The inexpensive aluminum nitrate and tetraethyl orthosilicate were used as sol precursors. • This organic–inorganic hybrid process can effectively enhance the thermal conductivity of PCMs. • The PCM exhibited high thermal stability and excellent form-stable effects

  13. A PEG/copper(i) halide cluster as an eco-friendly catalytic system for C-N bond formation.

    Science.gov (United States)

    Li, Cheng-An; Ji, Wei; Qu, Jian; Jing, Su; Gao, Fei; Zhu, Dun-Ru

    2018-05-22

    The catalytic activities of eight copper(i) halide clusters assembled from copper(i) halide and ferrocenyltelluroethers, 1-8, were investigated in C-N formation under various conditions. A catalytic procedure using poly(ethylene glycol) (PEG-400) as a greener alternative organic solvent has been developed. The PEG-400/5 system can achieve 99% targeted yield with a mild reaction temperature and short reaction time. After the isolation of the products by extraction with diethyl ether, this PEG-400/cluster system could be easily recycled. Spectroscopic studies elucidate a stepwise mechanism: firstly, proton-coupled electron transfer (PCET) involving the transfer of an electron from Cu+ and a proton from imidazole results in the formation of a labile penta-coordinated Cu2+ and aryl radical; the following effective electron transfer from the ferrocene unit reduces Cu2+ and forms the target product; finally, the ferrocenium unit is reduced by the I- anion. The merits of this eco-friendly synthesis are the efficient utilization of reagents and easy recyclability.

  14. Extension arm facilitated pegylation of alphaalpha-hemoglobin with modifications targeted exclusively to amino groups: functional and structural advantages of free Cys-93(beta) in the PEG-Hb adduct.

    Science.gov (United States)

    Li, Dongxia; Hu, Tao; Manjula, Belur N; Acharya, Seetharama A

    2009-11-01

    Cys-93(beta) of hemoglobin (Hb) was reversibly protected as a mixed disulfide with thiopyridine during extension arm facilitated (EAF) PEGylation and its influence on the structural and functional properties of the EAF-PEG-Hb has been investigated. Avoiding PEGylation of Cys-93(beta) in the EAF-PEG-Hb lowers the level of perturbation of heme pocket, alpha1beta2 interface, autoxidation, heme loss, and the O(2) affinity, as compared to the EAF-PEG-Hb with PEGylation of Cys-93(beta).The structural and functional advantages of reversible protection of Cys-93(beta) during EAF PEGylation of oxy-Hb has been compared with Euro PEG-Hb generated by EAF PEGylation of deoxy Hb where Cys-93(beta) is free in the final product. The alphaalpha-fumaryl cross-linking and EAF PEGylation targeted exclusively to Lys residues has been combined together for generation of second-generation EAF-PEG-Hb with lower oxygen affinity. The PEG chains engineered on Lys as well as PEGylation of Cys-93(beta) independently contribute to the stabilization of oxy conformation of Hb and hence increase the oxygen affinity of Hb. However, oxygen affinity of the EAF-PEG-alphaalpha-Hb is more sensitive to the presence of PEGylation on Cys-93(beta) than that of the EAF-PEG-Hb. The present modified EAF PEGylation platform is expected to facilitate the design of novel versions of the EAF-PEG-Hbs that can now integrate the advantages of avoiding PEGylation of Cys-93(beta).

  15. The In Vitro-In Vivo Safety Confirmation of PEG-40 Hydrogenated Castor Oil as a Surfactant for Oral Nanoemulsion Formulation.

    Science.gov (United States)

    Rachmawati, Heni; Novel, Miranti Anggraeni; Ayu, Sri; Berlian, Guntur; Tandrasasmita, Olivia Mayasari; Tjandrawinata, Raymond Rubianto; Anggadiredja, Kusnandar

    2017-03-31

    Evaluation on the safety use of high concentration of polyoxyl 40 (PEG-40) hydrogenated castor oil as a surfactant for oral nanoemulsion was performed in Webster mice. As previously reported, nearly 20% of PEG-40 hydrogenated castor oil was used to emulsify the glyceryl monooleate (GMO) as an oil to the aqueous phase. Thermodynamically stable and spontaneous nanoemulsion was formed by the presence of co-surfactant polyethylene glycol 400 (PEG-400). Standard parameters were analyzed for nanoemulsion including particle size and particle size distribution, the surface charge of nanoemulsion, and morphology. To ensure the safety of this nanoemulsion, several cell lines were used for cytotoxicity study. In addition, 5000 mg/kg body weight (BW) of the blank nanoemulsion was given orally to Webster mice once a day for 14 days. Several parameters such as gross anatomy, body weight, and main organs histopathology were observed. In particular, by considering the in vivo data, it is suggested that nanoemulsion composed with a high amount of PEG-40 hydrogenated castor oil is acceptable for oral delivery of active compounds.

  16. In vitro and in vivo effects of polyethylene glycol (PEG)-modified lipid in DOTAP/cholesterol-mediated gene transfection

    DEFF Research Database (Denmark)

    Gjetting, Torben; Arildsen, Nicolai Skovbjerg; Christensen, Camilla Laulund

    2010-01-01

    DOTAP/cholesterol-based lipoplexes are successfully used for delivery of plasmid DNA in vivo especially to the lungs, although low systemic stability and circulation have been reported. To achieve the aim of discovering the best method for systemic delivery of DNA to disseminated tumors we evalua...... evaluated the potential of formulating DOTAP/cholesterol lipoplexes with a polyethylene glycol (PEG)-modified lipid, giving the benefit of the shielding and stabilizing properties of PEG in the bloodstream....

  17. Renewable poly(δ-decalactone based block copolymer micelles as drug delivery vehicle: in vitro and in vivo evaluation

    Directory of Open Access Journals (Sweden)

    Kuldeep K. Bansal

    2018-03-01

    Full Text Available Polymers from natural resources are attracting much attention in various fields including drug delivery as green alternatives to fossil fuel based polymers. In this quest, novel block copolymers based on renewable poly(δ-decalactone (PDL were evaluated for their drug delivery capabilities and compared with a fossil fuel based polymer i.e. methoxy-poly(ethylene glycol-b-poly(ε-caprolactone (mPEG-b-PCL. Using curcumin as a hydrophobic drug model, micelles of PDL block copolymers with different orientation i.e. AB (mPEG-b-PDL, ABA (PDL-b-PEG-b-PDL, ABC (mPEG-b-PDL-b-poly(pentadecalactone and (mPEG-b-PCL were prepared by nanoprecipitation method. The size, drug loading and curcumin stability studies results indicated that mPEG-b-PDL micelles was comparable to its counterpart mPEG-b-PCL micelles towards improved delivery of curcumin. Therefore, mixed micelles using these two copolymers were also evaluated to see any change in size, loading and drug release. Drug release studies proposed that sustained release can be obtained using poly(pentadecalactone as crystalline core whereas rapid release can be achieved using amorphous PDL core. Further, mPEG-b-PDL micelles were found to be non-haemolytic, up to the concentration of 40 mg/mL. In vivo toxicity studies on rats advised low-toxic behaviour of these micelles up to 400 mg/kg dose, as evident by histopathological and biochemical analysis. In summary, it is anticipated that mPEG-b-PDL block copolymer micelles could serve as a renewable alternative for mPEG-b-PCL copolymers in drug delivery applications.

  18. POLYSACCHARIDES AND eDNA AID BACTERIAL ATTACHMENT TO POLYMER BRUSH COATINGS (PLL-g-PEG)

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Ogaki, Ryosuke; Regina, Viduthalai R.

    measured the adsorption of peptides, polysaccharides and DNA to these coatings, as they represent bacterial adhesins with very different properties. While protein adsorption was minimized, we found considerable adsorption of polysaccharides, and exposure to DNA resulted in complete desorption...... of the conventional coating. These results explain why S. epidermidis, which produces polysaccharides and extracellular DNA, could successfully colonize the conventional PLL-g-PEG coatings. The ability of high-density PLL-g-PEG to resist polysaccharides, DNA, and bacterial adhesion of all strains is thus highly......Polymer brush coatings of poly(ethylene glycol) are considered the gold standard for nonfouling surfaces, but nevertheless, a few bacteria manage to attach and initiate biofilm formation on these coatings. To achieve robust resistance against bacterial adhesion and biofilm formation, grafting...

  19. An estimate of the system parameters in the dwarf nova IP Peg

    International Nuclear Information System (INIS)

    Wood, Janet; Crawford, C.S.

    1986-01-01

    High-speed photometry of the eclipsing dwarf nova IP Peg is used to estimate the geometry of the binary system and the masses of its components. A white dwarf eclipse width between 0.0863 and 0.0918, is found and hence constraints on the mass ratio, q, of 0.35#lt#q#lt#0.49 and on the inclination, i, of 80 0 .9#lt#i#lt#90 0 . The white dwarf is surrounded by an extended boundary layer and has a mass of at least Msub(WD) approx.0.3 solar mass, probably much greater, depending on the thickness of the boundary layer and the orbital inclination. Its mass could be as high as 0.9 solar mass for an inclination of 80 0 .9. The mass of the secondary star is greater than 0.09 solar mass probably a lot higher. IP Peg could be earlier in the evolutionary sequence of dwarf novae than the ultra-short-period system (P#lt#2hr). (author)

  20. PEG-PE/clay composite carriers for doxorubicin: Effect of composite structure on release, cell interaction and cytotoxicity.

    Science.gov (United States)

    Kohay, Hagay; Sarisozen, Can; Sawant, Rupa; Jhaveri, Aditi; Torchilin, Vladimir P; Mishael, Yael G

    2017-06-01

    A novel drug delivery system for doxorubicin (DOX), based on organic-inorganic composites was developed. DOX was incorporated in micelles (M-DOX) of polyethylene glycol-phosphatidylethanolamine (PEG-PE) which in turn were adsorbed by the clay, montmorillonite (MMT). The nano-structures of the PEG-PE/MMT composites of LOW and HIGH polymer loadings were characterized by XRD, TGA, FTIR, size (DLS) and zeta measurements. These measurements suggest that for the LOW composite a single layer of polymer intercalates in the clay platelets and the polymer only partially covers the external surface, while for the HIGH composite two layers of polymer intercalate and a bilayer may form on the external surface. These nanostructures have a direct effect on formulation stability and on the rate of DOX release. The release rate was reversely correlated with the degree of DOX interaction with the clay and followed the sequence: M-DOX>HIGH formulation>LOW formulation>DOX/MMT. Despite the slower release from the HIGH formulation, its cytotoxicity effect on sensitive cells was as high as the "free" DOX. Surprisingly, the LOW formulation, with the slowest release, demonstrated the highest cytotoxicity in the case of Adriamycin (ADR) resistant cells. Confocal microscopy images and association tests provided an insight into the contribution of formulation-cell interactions vs. the contribution of DOX release rate. Internalization of the formulations was suggested as a mechanism that increases DOX efficiency, particularly in the ADR resistant cell line. The employment of organic-inorganic hybrid materials as drug delivery systems, has not reached its full potential, however, its functionality as an efficient tunable release system was demonstrated. DOX PEG-PE/clay formulations were design as an efficient drug delivery system. The main aim was to develop PEG-PE/clay formulations of different structures based on various PEG-PE/clay ratios in order to achieve tunable release rates, to control

  1. Tolerancia, seguridad y eficacia de la preparación intestinal con un día de PEG3350 + bisacodilo en comparación con 2 días de PEG3350 + bisacodilo en pacientes pediátricos

    OpenAIRE

    Ligia Marcela Portillo Canizalez; Gerardo Blanco Rodriguez; Gustavo Teyssier Morales; Jaime Penchyna Grub; Sean Trauernicht Mendieta; Jessie Nallely Zurita-Cruz

    2017-01-01

    Introducción: Múltiples preparaciones intestinales se han utilizado en niños sometidos a una colonoscopia, con limitación variable debido a la aceptación, tolerancia y la limpieza adecuada. El objetivo del estudio fue comparar la tolerancia seguridad y eficacia de la preparación intestinal para colonoscopia de 1 día con PEG 3350 (polietilenglicol) (4 g/kg/día) + bisacodilo y el tratamiento con 2 días de preparación con PEG 3350 (2 g/kg/día) + bisacodilo en pacientes pediátricos. Métodos: S...

  2. Inflammatory responses of a human keratinocyte cell line to 10 nm citrate- and PEG-coated silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, V. [University of Aveiro, CESAM & Laboratory of Biotechnology and Cytomics (Portugal); Brown, D.; Johnston, H. [Heriot-Watt University, School of Life Sciences (United Kingdom); Daniel-da-Silva, A. L.; Duarte, I. F. [University of Aveiro, Department of Chemistry, CICECO – Aveiro Institute of Materials (Portugal); Santos, C., E-mail: csantos@fc.up.pt; Oliveira, H. [University of Aveiro, CESAM & Laboratory of Biotechnology and Cytomics (Portugal)

    2016-07-15

    Silver nanoparticles (AgNPs) are among the most commonly used engineered NPs and various commercially available products are designed to come in direct contact with the skin (wound dressings, textiles, creams, among others). Currently, there is limited understanding of the influence of coatings on the toxicity of AgNPs and in particular their ability to impact on AgNP’s mediated inflammatory responses. As AgNPs are often stabilized by different coatings, including citrate and polyethyleneglycol (PEG), in this study we investigate the influence of citrate (Cit10) or PEG (PEG10) coatings to 10 nm AgNP on skin, using human HaCaT keratinocytes. AgNPs cytotoxicity and inflammatory response (nuclear factor (NF)-κB induction and cytokine production) of HaCaT were assessed after in vitro exposure to 10 and 40 µg/mL after 4, 24, and 48 h. Results showed that although both types of coated AgNPs decreased cell proliferation and viability, Cit10 AgNPs were more toxic. NF-κB inhibition was observed for the highest concentration (40 µg/mL) of PEG10 AgNPs, and the putative link to early apoptotic pathways observed in these cells is discussed. No production of IL-1β, IL-6, IL-10, and TNFα was stimulated by AgNPs. Furthermore, Cit10 and PEG10 AgNPs decreased the release of MCP-1 by HaCaT cells after 48 h of exposure. As cytokines are vital for the immunologic regulation in the human body, and it is demonstrated that they may interfere with NPs, more research is needed to understand how different AgNPs affect the immune system.

  3. Mmp-9 responsive PEG cleavable nanovesicles for efficient delivery of chemotherapeutics to pancreatic cancer.

    Science.gov (United States)

    Kulkarni, Prajakta S; Haldar, Manas K; Nahire, Rahul R; Katti, Preeya; Ambre, Avinash H; Muhonen, Wallace W; Shabb, John B; Padi, Sathish K R; Singh, Raushan K; Borowicz, Pawel P; Shrivastava, D K; Katti, Kalpana S; Reindl, Katie; Guo, Bin; Mallik, Sanku

    2014-07-07

    Significant differences in biochemical parameters between normal and tumor tissues offer an opportunity to chemically design drug carriers which respond to these changes and deliver the drugs at the desired site. For example, overexpression of the matrix metalloproteinase-9 (MMP-9) enzyme in the extracellular matrix of tumor tissues can act as a trigger to chemically modulate the drug delivery from the carriers. In this study, we have synthesized an MMP-9-cleavable, collagen mimetic lipopeptide which forms nanosized vesicles with the POPC, POPE-SS-PEG, and cholesteryl-hemisuccinate lipids. The lipopeptide retains the triple-helical conformation when incorporated into these nanovesicles. The PEG groups shield the substrate lipopeptides from hydrolysis by MMP-9. However, in the presence of elevated glutathione levels, the PEG groups are reductively removed, exposing the lipopeptides to MMP-9. The resultant peptide-bond cleavage disturbs the vesicles' lipid bilayer, leading to the release of encapsulated contents. These PEGylated nanovesicles are capable of encapsulating the anticancer drug gemcitabine with 50% efficiency. They were stable in physiological conditions and in human serum. Effective drug release was demonstrated using the pancreatic ductal carcinoma cells (PANC-1 and MIAPaCa-2) in two-dimensional and three-dimensional "tumor-like" spheroid cultures. A reduction in tumor growth was observed after intravenous administration of the gemcitabine-encapsulated nanovesicles in the xenograft model of athymic, female nude mice.

  4. A one-step in-situ assembly strategy to construct PEG@MOG-100-Fe shape-stabilized composite phase change material with enhanced storage capacity for thermal energy storage

    Science.gov (United States)

    Wang, Junyong; Andriamitantsoa, Radoelizo S.; Atinafu, Dimberu G.; Gao, Hongyi; Dong, Wenjun; Wang, Ge

    2018-03-01

    A novel in-situ assembly strategy has been developed to synthesis polyethylene glycol (PEG)@iron-benzenetricarboxylate metal-organic gel (MOG-100-Fe) shape-stabilized composite phase change materials by regulating metal-to-ligand ratio. The PEG@MOG-100-Fe was prepared by an ingenious introduction of PEG into the traditional sol-gel prepared MOG-100-Fe. The composite exhibited high heat storage density and thermal stability. The PEG loading content reached up to 92% without any leakage above its melting point. The heat storage density reaches to 152.88

  5. [A multicenter, randomized, controlled, phase Ⅳ clinical study of PEG-rhG-CSF for preventing chemotherapy induced neutropenia in patients with breast cancer].

    Science.gov (United States)

    Jiang, Z F; Xu, F R; Fan, J; Li, B J; Gao, J N; Hu, J W; Wang, X J; Zhang, Y Q; Wang, J H; Li, F; Liu, Q; Liu, Y H; Wang, S; Wang, Y S; Ouyang, Q C; Hu, B; Sun, G P; Zhang, Y; Zang, A M; Fan, P Z; Wu, C P; Liu, J; Zhang, H W; Wang, W; Hu, X C; Tang, L L; Zhang, J; Bao, Y Y; Geng, C Z; Sun, Q; Zhang, F; Yin, Y M; Jiang, H C; An, Y H

    2018-04-24

    Objective: To explore the efficacy and safety of polyethylene glycal recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in preventing chemotherapy-induced neutropenia in patiens with breast cancer. Methods: There were two parts in the present phase Ⅳ clinical study. One was a randomized, controlled clinical study. Patients in this study received PEG-rhG-CSF or rhG-CSF in the first cycle and followed with both PEG-rhG-CSF in the rest of 3 cycles. The other one was a single arm study. Patients who developed Ⅲ/Ⅳ grade neutropenia in the screening cycle received PEG-rhG-CSF in the rest of 3 cycles chemotherapy. Results: In the first cycle of randomized, controlled study, the incidence of Ⅳ grade neutropenia are 31.48% and 35.58% respectively in PEG-rhG-CSF and rhG-CSF group, with no statistically significant differences ( P =0.527 6). The duration of Ⅳ grade neutropenia respectively are 2.22±1.58 and 3.00±1.59 days, with a statistically significant difference ( P =0.016 6). In the single arm study, the incidence of Ⅳ grade neutropenia was 57.76% in screening cycle. And the incidence decreased to 16.35%, 10%, and 8.57% in the followed 3 cycle after the use of PEG-rhG-CSF. The incidence of adverse effects was 5.06%, and the major adverse effect was bone pain which with an incidence of 2.8%. Conclusion: The fixed 6mg dose of PEG-rhG-CSF can effectively prevent neutropenia in patients with breast cancer in multicycle chemotherapy and it has a low incidence of adverse events and mild adverse reaction.

  6. Is survival improved by the use of NIV and PEG in amyotrophic lateral sclerosis (ALS)? A post-mortem study of 80 ALS patients.

    Science.gov (United States)

    Burkhardt, Christian; Neuwirth, Christoph; Sommacal, Andreas; Andersen, Peter M; Weber, Markus

    2017-01-01

    Non-invasive ventilation (NIV) and percutaneous gastrostomy (PEG) are guideline-recommended interventions for symptom management in amyotrophic lateral sclerosis (ALS). Their effect on survival is controversial and the impact on causes of death is unknown. To investigate the effect of NIV and PEG on survival and causes of death in ALS patients. Eighty deceased ALS patients underwent a complete post mortem analysis for causes of death between 2003 and 2015. Forty-two of these patients consented for genetic testing. Effects of NIV and PEG on survival and causes of death were analyzed in a multivariable Cox proportional hazard regression. Six patients, who requested assisted suicide causing drug-induced hypoxia, were excluded from final analysis. Respiratory failure was the main cause of death in 72 out of 74 patients. Fifteen out of 74 died of aspiration pneumonia 23/74 of bronchopneumonia and 8/74 of a combination of aspiration pneumonia and bronchopneumonia. Twenty died of hypoxia without concomitant infection, and six patients had pulmonary embolism alone or in combination with pneumonia. NIV (p = 0.01) and PEG (pNIV bronchopneumonia was significantly more frequent (p NIV patients. This effect was even more pronounced in limb onset patients (pNIV and PEG prolongs survival in ALS. This study supports current AAN and EFNS guidelines which recommend NIV and PEG as a treatment option in ALS. The risk of bronchopneumonia as cause of death may be increased by NIV.

  7. Peg-interferon plus nucleotide analogue treatment versus no treatment in patients with chronic hepatitis B with a low viral load: a randomised controlled, open-label trial.

    Science.gov (United States)

    de Niet, Annikki; Jansen, Louis; Stelma, Femke; Willemse, Sophie B; Kuiken, Sjoerd D; Weijer, Sebastiaan; van Nieuwkerk, Carin M J; Zaaijer, Hans L; Molenkamp, Richard; Takkenberg, R Bart; Koot, Maarten; Verheij, Joanne; Beuers, Ulrich; Reesink, Hendrik W

    2017-08-01

    Antiviral treatment is currently not recommended for patients with chronic hepatitis B with a low viral load. However, they might benefit from acquiring a functional cure (hepatitis B surface antigen [HBsAg] loss with or without formation of antibodies against hepatitis B surface antigen [anti-HBs]). We assessed HBsAg loss during peg-interferon-alfa-2a (peg-IFN) and nucleotide analogue combination therapy in patients with chronic hepatitis B with a low viral load. In this randomised controlled, open-label trial, patients were enrolled from the Academic Medical Center (AMC), Amsterdam, Netherlands. Eligible patients were HBsAg positive and hepatitis B e antigen (HBeAg) negative for more than 6 months, could be treatment naive or treatment experienced, and had alanine aminotransferase (ALT) concentrations less than 5 × upper limit of normal (ULN). Participants were randomly assigned (1:1:1) by a computerised randomisation programme (ALEA Randomisation Service) to receive peg-IFN 180 μg/week plus adefovir 10 mg/day, peg-IFN 180 μg/week plus tenofovir disoproxil fumarate 245 mg/day, or no treatment for 48 weeks. The primary endpoint was the proportion of patients with serum HBsAg loss among those who received at least one dose of study drug or had at least one study visit (modified intention-to-treat population [mITT]). All patients have finished the initial study of 72 weeks and will be observed for up to 5 years of follow-up. This study is registered with ClinicalTrials.gov, number NCT00973219. Between Aug 4, 2009, and Oct 17, 2013, 167 patients were screened for enrolment, of whom 151 were randomly assigned (52 to peg-IFN plus adefovir, 51 to peg-IFN plus tenofovir, and 48 to no treatment). 46 participants in the peg-IFN plus adefovir group, 45 in the peg-IFN plus tenofovir group, and 43 in the no treatment group began treatment or observation and were included in the mITT population. At week 72, two (4%) patients in the peg-IFN plus adefovir group and two (4

  8. Basic geriatric assessment does not predict in-hospital mortality after PEG placement

    Directory of Open Access Journals (Sweden)

    Smoliner Christine

    2012-09-01

    Full Text Available Abstract Background Percutaneous endoscopic gastrostomy (PEG is an established procedure for long-term nutrition. However, studies have underlined the importance of proper patient selection as mortality has been shown to be relatively high in acute illness and certain patient groups, amongst others geriatric patients. Objective of the study was to gather information about geriatric patients receiving PEG and to identify risk factors associated with in-hospital mortality after PEG placement. Methods All patients from the GEMIDAS database undergoing percutaneous endoscopic gastrostomy in acute geriatric wards from 2006 to 2010 were included in a retrospective database analysis. Data on age, gender, main diagnosis leading to hospital admission, death in hospital, care level, and legal incapacitation were extracted from the main database of the Geriatric Minimum Data Set. Self-care capacity was assessed by the Barthel index, and cognitive status was rated with the Mini Mental State Examination or subjectively judged by the clinician. Descriptive statistics and group comparisons were chosen according to data distribution and scale of measurement, logistic regression analysis was performed to examine influence of various factors on hospital mortality. Results A total of 1232 patients (60.4% women with a median age of 82 years (range 60 to 99 years were included. The mean Barthel index at admission was 9.5 ± 14.0 points. Assessment of cognitive status was available in about half of the patients (n = 664, with 20% being mildly impaired and almost 70% being moderately to severely impaired. Stroke was the most common main diagnosis (55.2%. In-hospital mortality was 12.8%. In a logistic regression analysis, old age (odds ratio (OR 1.030, 95% confidence interval (CI 1.003-1.056, male sex (OR 1.741, 95% CI 1.216-2.493, and pneumonia (OR 2.641, 95% CI 1.457-4.792 or the diagnosis group ‘miscellaneous disease’ (OR 1.864, 95% CI 1

  9. Financial policy and speculative runs with a crawling peg: Argentina 1979-1981

    NARCIS (Netherlands)

    van Wijnbergen, S.J.G.

    1989-01-01

    This paper presents a model of a balance-of-payment crisis and examines the financial policy of the Argentine government in dealing with the speculative runs on the peg between December 1978 and February 1981. The evolution of a crisis when a collapse is not perfectly foreseen; The factors that

  10. Purification of a fibrinolytic protease from Mucor subtilissimus UCP 1262 by aqueous two-phase systems (PEG/sulfate).

    Science.gov (United States)

    Nascimento, Thiago Pajeú; Sales, Amanda Emmanuelle; Porto, Camila Souza; Brandão, Romero Marcos Pedrosa; de Campos-Takaki, Galba Maria; Teixeira, José Antônio Couto; Porto, Tatiana Souza; Porto, Ana Lúcia Figueiredo; Converti, Attilio

    2016-07-01

    A fibrinolytic protease from M. subtilissimus UCP 1262 was recovered and partially purified by polyethylene glycol (PEG)/sodium sulfate aqueous two-phase systems (ATPS). The simultaneous influence of PEG molar mass, PEG concentration and sulfate concentration on the enzyme recovery was first investigated using a 2(3) full factorial design, and the Response Surface Methodology used to identify the optimum conditions for enzyme extraction by ATPS. Once the best PEG molar mass for the process had been selected (6000g/mol), a two-factor central composite rotary design was applied to better evaluate the effects of the other two independent variables. The fibrinolytic enzyme was shown to preferentially partition to the bottom phase with a partition coefficient (K) ranging from 0.2 to 0.7. The best results in terms of enzyme purification were obtained with the system formed by 30.0% (w/w) PEG 6000g/mol and 13.2% (w/w) sodium sulfate, which ensured a purification factor of 10.0, K of 0.2 and activity yield of 102.0%. SDS-PAGE and fibrin zymography showed that the purified protease has a molecular mass of 97kDa and an apparent isoelectric point of 5.4. When submitted to assays with different substrates and inhibitors, it showed selectivity for succinyl-l-ala-ala-pro-l-phenylalanine-p-nitroanilide and was almost completely inhibited by phenylmethylsulfonyl fluoride, behaving as a chymotrypsin-like protease. At the optimum temperature of 37°C, the enzyme residual activity was 94 and 68% of the initial one after 120 and 150min of incubation, respectively. This study demonstrated that M. subtilissimus protease has potent fibrinolytic activity compared with similar enzymes produced by solid-state fermentation, therefore it may be used as an agent for the prevention and therapy of thrombosis. Furthermore, it appears to have the advantages of low cost production and simple purification. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Screening Effect of PEG on Avidin Binding to Liposome Surface Receptors

    DEFF Research Database (Denmark)

    Kaasgaard, Thomas; Mouritsen, Ole G.; Jørgensen, Kent

    2000-01-01

    This study investigates the screening effect of poly(ethylene glycol)-phospholipids (PE-PEG) on the interaction of avidin with PEGylated liposomes containing surface-bound biotin ligands. The influence of grafting density and lipopolymer chain length is examined. A simple fluorescence assay....... Furthermore. it is found that none of the lipopolymers completely prevents avidin from reaching the surface-bound biotin ligands....

  12. Rectal Fecal Impaction Treatment in Childhood Constipation: Enemas Versus High Doses Oral PEG

    NARCIS (Netherlands)

    Bekkali, Noor-L.-Houda; van den Berg, Maartje-Maria; Dijkgraaf, Marcel G. W.; van Wijk, Michiel P.; Bongers, Marloes E. J.; Liem, Olivia; Benninga, Marc A.

    2009-01-01

    OBJECTIVE: We hypothesized that enemas and polyethylene glycol (PEG) would be equally effective in treating rectal fecal impaction (RFI) but enemas would be less well tolerated and colonic transit time (CTT) would improve during disimpaction. METHODS: Children (4-16 years) with functional

  13. Influence of the polymer amount on bioactivity and biocompatibility of SiO{sub 2}/PEG hybrid materials synthesized by sol–gel technique

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Bollino, F.; Papale, F. [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (Italy); Gallicchio, M.; Pacifico, S. [Department of Environmental Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta (Italy)

    2015-03-01

    SiO{sub 2}/PEG organic–inorganic hybrid materials, which differ in polyethylene glycol (PEG) content, were synthesized by sol–gel technique and the characterization of their structure and biological properties was carried out in order to evaluate the possible use in biomedical field. FT-IR spectroscopy detected that the two components of the hybrids (SiO{sub 2} and PEG) are linked by hydrogen bonds between the Si–OH groups of the inorganic phase and the terminal alcoholic groups and/or the ethereal oxygen atoms in the repeating units of polymer. X-ray diffraction analysis ascertained the amorphous nature of the gels and the observation of their morphology by SEM microscopy confirmed that the interpenetration of the two phases (organic and inorganic) occurs on nanometric scale. The biological characterization was carried out as a function of the polymer amount to study its influence on material behavior. The results showed that the synthesized materials were bioactive and biocompatible. The formation of a hydroxyapatite layer, indeed, was observed on their surface by SEM/EDX analysis after soaking in simulated body fluid. Moreover, the biocompatibility of SiO{sub 2}/PEG hybrids was assessed performing MTT and SRB cytotoxicity tests on fibroblast cell NIH 3T3 after 24 and 48 h of exposure, as well as Trypan Blue dye exclusion test. The response to the presence of the investigated materials was positive. The cell growth and proliferation showed dependence on polymer amount and time of exposure to the material extracts. Therefore, the obtained results are encouraging for the use of the obtained hybrids in dental or orthopedic applications. - Highlights: • SiO{sub 2}/PEG hybrid biomaterials synthesized by sol–gel method at various PEG percentages • Chemical and morphological characterization of hybrid materials • Chemical interactions between inorganic and organic components • Biological characterizations with MTT and SRB cytotoxicity tests

  14. Poly(ethylene glycol)-containing hydrogel surfaces for antifouling applications in marine and freshwater environments

    NARCIS (Netherlands)

    Ekblad, T.; Bergström, G.; Ederth, T.; Conlan, S.L.; Mutton, R.; Clare, A.S.; Wang, S.; Liu, Y.; Zhao, Q.; D'Souza, F.; Donnelly, G.T.; Willemsen, P.R.; Pettitt, M.E.; Callow, M.E.; Callow, J.A.; Liedberg, B.

    2008-01-01

    This work describes the fabrication, characterization, and biological evaluation of a thin protein-resistant poly(ethylene glycol) (PEG)-based hydrogel coating for antifouling applications. The coating was fabricated by free-radical polymerization on silanized glass and silicon and on

  15. (PCL/AA) hydrogel for controlled drug delivery

    Indian Academy of Sciences (India)

    Administrator

    applications, (iii) dental applications, (iv) injectable polymers, (v) ... PCL with AA grafted PCL(PCL-g-AA) on the structure ... porosity. Structure, morphology and crystallinity of PCL/ .... X-ray diffraction patterns were recorded, in reflection,.

  16. The Role of pH in PEG-b-PAAc Modification of Gadolinium Oxide Nanostructures for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Eva Hemmer

    2012-01-01

    Full Text Available Upconversion and near-infrared emitting Gd2O3:Er3+,Yb3+ nanostructured phosphors (nanoparticles and nanorods for applications in bioimaging have been synthesized by precipitation methods and hydrothermal treatment. Variation of the material synthesis conditions (additives and pH allows controlling particle size (40 nm to μm range and rod aspect ratio (5 to 18. It was shown that PEG-b-PAAc (poly(ethylene glycol poly(acrylic acid block polymer is suitable to provide the required chemical durability, dispersion stability, and noncytotoxic behaviour for biomedical applications, where the coating of Gd2O3 with a protecting and biocompatible layer is essential in order to prevent the release of toxic Gd3+ ions. Physicochemical properties of the Gd2O3:Er3+,Yb3+ nanostructures modified with PEG-b-PAAc have been investigated by TG-DTA, FT-IR, and DLS revealing a strong influence of modification conditions, namely, pH of the reaction media, on the nature of the PEG-b-PAAc layer.

  17. Injectable hydrogel as stem cell scaffolds from the thermosensitive terpolymer of NIPAAm/AAc/HEMAPCL

    Directory of Open Access Journals (Sweden)

    Lian S

    2012-09-01

    Full Text Available Sheng Lian,1Yan Xiao,1 Qingqing Bian,1Yu Xia,2 Changfa Guo,2 Shenguo Wang,2 Meidong Lang11Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, People's Republic of China; 2Department of Cardiac Surgery, Zhongshan Hospital, Fudan University and Shanghai Institute of Cardiovascular Diseases, Shanghai, People's Republic of ChinaAbstract: A series of biodegradable thermosensitive copolymers was synthesized by free radical polymerization with N-isopropylacrylamide (NIPAAm, acrylic acid (AAc and macromer 2-hydroxylethyl methacrylate-poly(ε-caprolactone (HEMAPCL. The structure and composition of the obtained terpolymers were confirmed by proton nuclear magnetic resonance spectroscopy, while their molecular weight was measured using gel permeation chromatography. The copolymers were dissolved in phosphate-buffered saline (PBS solution (pH = 7.4 with different concentrations to prepare hydrogels. The lower critical solution temperature (LCST, cloud point, and rheological property of the hydrogels were determined by differential scanning calorimetry, ultraviolet-visible spectrometry, and rotational rheometry, respectively. It was found that LCST of the hydrogel increased significantly with the increasing NIPAAm content, and hydrogel with higher AAc/HEMAPCL ratio exhibited better storage modulus, water content, and injectability. The hydrogels were formed by maintaining the copolymer solution at 37°C. The degradation experiment on the formed hydrogels was conducted in PBS solution for 2 weeks and demonstrated a less than 20% weight loss. Scanning electron microscopy was also used to study the morphology of the hydrogel. The copolymer with NIPAAm/AAc/HEMAPCL ratio of 88:9.6:2.4 was bioconjugated with type I collagen for the purpose of biocompatibility enhancement. In-vitro cytotoxicity

  18. Modeling Alveolar Epithelial Cell Behavior In Spatially Designed Hydrogel Microenvironments

    Science.gov (United States)

    Lewis, Katherine Jean Reeder

    The alveolar epithelium consists of two cell phenotypes, elongated alveolar type I cells (AT1) and rounded alveolar type II cells (ATII), and exists in a complex three-dimensional environment as a polarized cell layer attached to a thin basement membrane and enclosing a roughly spherical lumen. Closely surrounding the alveolar cysts are capillary endothelial cells as well as interstitial pulmonary fibroblasts. Many factors are thought to influence alveolar epithelial cell differentiation during lung development and wound repair, including physical and biochemical signals from the extracellular matrix (ECM), and paracrine signals from the surrounding mesenchyme. In particular, disrupted signaling between the alveolar epithelium and local fibroblasts has been implicated in the progression of several pulmonary diseases. However, given the complexity of alveolar tissue architecture and the multitude of signaling pathways involved, designing appropriate experimental platforms for this biological system has been difficult. In order to isolate key factors regulating cellular behavior, the researcher ideally should have control over biophysical properties of the ECM, as well as the ability to organize multiple cell types within the scaffold. This thesis aimed to develop a 3D synthetic hydrogel platform to control alveolar epithelial cyst formation, which could then be used to explore how extracellular cues influence cell behavior in a tissue-relevant cellular arrangement. To accomplish this, a poly(ethylene glycol) (PEG) hydrogel network containing enzymatically-degradable crosslinks and bioadhesive pendant peptides was employed as a base material for encapsulating primary alveolar epithelial cells. First, an array of microwells of various cross-sectional shapes was photopatterned into a PEG gel containing photo-labile crosslinks, and primary ATII cells were seeded into the wells to examine the role of geometric confinement on differentiation and multicellular arrangement

  19. Enzymatic mineralization of hydrogels for bone tissue engineering by incorporation of alkaline phosphatase.

    NARCIS (Netherlands)

    Douglas, T.E.L.; Messersmith, P.B.; Chasan, S.; Mikos, A.G.; Mulder, E.L.W. de; Dickson, G.; Schaubroeck, D.; Balcaen, L.; Vanhaecke, F.; Dubruel, P.; Jansen, J.A.; Leeuwenburgh, S.C.G.

    2012-01-01

    Alkaline phosphatase (ALP), an enzyme involved in mineralization of bone, is incorporated into three hydrogel biomaterials to induce their mineralization with calcium phosphate (CaP). These are collagen type I, a mussel-protein-inspired adhesive consisting of PEG substituted with catechol groups,

  20. Biocompatible and colloidally stabilized mPEG-PE/calcium phosphate hybrid nanoparticles loaded with siRNAs targeting tumors.

    Science.gov (United States)

    Gao, Pei; Zhang, Xiangyu; Wang, Hongzhi; Zhang, Qinghong; Li, He; Li, Yaogang; Duan, Yourong

    2016-01-19

    Calcium phosphate nanoparticles are safe and effective delivery vehicles for small interfering RNA (siRNA), as a result of their excellent biocompatibility. In this work, mPEG-PE (polyethylene glycol-L-α-phosphatidylethanolamine) was synthesized and used to prepare nanoparticles composed of mPEG-PE and calcium phosphate for siRNA delivery. Calcium phosphate and mPEG-PE formed the stable hybrid nanoparticles through self-assembly resulting from electrostatic interaction in water. The average size of the hybrid nanoparticles was approximately 53.2 nm with a negative charge of approximately -16.7 mV, which was confirmed by dynamic light scattering (DLS) measurements. The nanoparticles exhibited excellent stability in serum and could protect siRNA from ribonuclease (RNase) degradation. The cellular internalization of siRNA-loaded nanoparticles was evaluated in SMMC-7721 cells using a laser scanning confocal microscope (CLSM) and flow cytometry. The hybrid nanoparticles could efficiently deliver siRNA to cells compared with free siRNA. Moreover, the in vivo distribution of Cy5-siRNA-loaded hybrid nanoparticles was observed after being injected into tumor-bearing nude mice. The nanoparticles concentrated in the tumor regions through an enhanced permeability and retention (EPR) effect based on the fluorescence intensities of tissue distribution. A safety evaluation of the nanoparticles was performed both in vitro and in vivo demonstrating that the hybrid nanoparticle delivery system had almost no toxicity. These results indicated that the mPEG-PE/CaP hybrid nanoparticles could be a stable, safe and promising siRNA nanocarrier for anticancer therapy.

  1. Stabilization of bacterially expressed erythropoietin by single site-specific introduction of short branched PEG chains at naturally occurring glycosylation sites.

    Science.gov (United States)

    Hoffmann, E; Streichert, K; Nischan, N; Seitz, C; Brunner, T; Schwagerus, S; Hackenberger, C P R; Rubini, M

    2016-05-24

    The covalent attachment of polyethylene glycol (PEG) to therapeutic proteins can improve their physicochemical properties. In this work we utilized the non-natural amino acid p-azidophenylalanine (pAzF) in combination with the chemoselective Staudinger-phosphite reaction to install branched PEG chains to recombinant unglycosylated erythropoietin (EPO) at each single naturally occurring glycosylation site. PEGylation with two short 750 or 2000 Da PEG units at positions 24, 38, or 83 significantly decreased unspecific aggregation and proteolytic degradation while biological activity in vitro was preserved or even increased in comparison to full-glycosylated EPO. This site-specific bioconjugation approach permits to analyse the impact of PEGylation at single positions. These results represent an important step towards the engineering of site-specifically modified EPO variants from bacterial expression with increased therapeutic efficacy.

  2. Live RB51 vaccine lyophilized hydrogel formulations with increased shelf life for practical ballistic delivery

    Science.gov (United States)

    Ballistic delivery capability is essential to delivering vaccines and other therapeutics effectively to both livestock and wildlife in many global scenarios. Here, lyophilized poly(ethylene glycol) (PEG)-glycolide dimethacrylate crosslinked but degradable hydrogels were assessed as payload vehicles ...

  3. Hydrothermal fabrication of hydroxyapatite on the PEG-grafted surface of wood from Chinese Glossy Privet

    Science.gov (United States)

    Wang, Ning; Cai, Chuanjie; Cai, Dongqing; Cheng, Junjie; Li, Shengli; Wu, Zhengyan

    2012-10-01

    Wood-hydroxyapatite composite material was developed by depositing hydrated calcium hydrogen phosphate (HCHP) on the surface of wood from Chinese Glossy Privet (CGP) with polyethylene glycol (PEG, HO(CH2CH2O)nH) as the grafting agent and subsequent hydrothermal vapor treatment. The results illustrated that HCHP could adhere quickly and strongly on the PEG-grafted wood surface. Moreover, this HCHP could be efficiently transformed to hydroxyapatite (HA, Ca10(PO4)6(OH)2) by hydrothermal vapor treatment. IR, XRD analysis and SEM observation indicated that the fabricated hydroxyapatite was pure and its morphology was uniform and microporous. This work provides a new fabricating approach of biocompatible material which may have some potential applications as bone-repairing material.

  4. Mussel-Inspired Dopamine and Carbon Nanotube Leading to a Biocompatible Self-Rolling Conductive Hydrogel Film.

    Science.gov (United States)

    Jiang, Junzi; Huang, Yong; Wang, Yitian; Xu, Hui; Xing, Malcolm; Zhong, Wen

    2017-08-18

    We report a novel self-rolling, conductive, and biocompatible multiwall carbon nanotube (MWCNT)-dopamine-polyethylene glycol (PEG) hydrogel film. The gel can self-fold into a thin tube when it is transferred from a glass slide to an aqueous environment, regardless of the concentrations of the MWCNT. The film presents a highly organized pattern, which results from the self-assembly of hydrophilic dopamine and hydrophobic carbon nanotubes. By exploring the biomedical potential, we found that MWCNT-included rolled film is nontoxic and can promote cell growth. For further functional verification by qPCR (quantitative polymerase chain reaction), bone marrow derived mesenchymal cells present higher levels of osteogenic differentiations in response to a higher concentration of CNTs. The results suggest that the self-rolling, conductive CNT-dopamine-PEG hydrogel could have multiple potentials, including biomedical usage and as a conductive biosensor.

  5. Extraction of lipase from Burkholderia cepacia by PEG/Phosphate ATPS and its biochemical characterization

    Directory of Open Access Journals (Sweden)

    Giovana da Silva Padilha

    2012-02-01

    Full Text Available This work aimed to study the partitioning of a lipase produced by Burkholderia cepacia in PEG/Phosphate aqueous two phase system (ATPS and its characterization. Lipase was produced by B. cepacia strains in a fermenter. Enzyme partitioning occurred at pH 6.0 and 8.0, using PEG 1500 and 6000 on two tie lines. Metal ions, pH and temperature effects on enzyme activity were evaluated. Five milliliter of 7.5% olive oil emulsion with 2.5% gumarabic in 0.1M sodium phosphate buffer at pH 8.0 and 37ºC were used for the activity determinations. Results showed that crude stratum from B. cepacia was partitioned by PEG1500/phosphate ATPS at pH 6.0 or 8.0 for, which the partitioning coefficients were 108-and 209-folds. Lipase presented optimal activity conditions at 37ºC and pH 8.0; it showed pH-stability for 4 h of incubation at different pH values at 37ºC. Metal ions such as Mn2+ , Co2+, I-and Ca2+ sustained enzymatic activities; however, it was inhibited by the presence of Fe2+, Hg2+ and Al3+ . Km and Vmax values were 0.258 U/mg and 43.90 g/L, respectively. A molecular weight of 33 kDa and an isoelectric point at pH 5.0 were determined by SDS-PAGE and IFS electrophoresis, respectively.

  6. Tailoring the properties of mPEG-PLLA nanoparticles for better encapsulation and tuned release of the hydrophilic anticancer drug.

    Science.gov (United States)

    Surwase, Sachin S; Munot, Neha M; Idage, Bhaskar B; Idage, Susheela B

    2017-06-01

    Gemcitabine is used as a first-line drug for treating many solid tumours. However, it suffers from a major drawback of strong side effects and short plasma half-life because of degradation by enzyme when administered intravenously. Polyesters and copolyesters are the most widely used and preferred class of biodegradable polymer. In the present work, efforts have been made to prepare poly(ethylene glycol) monomethoxy ether-poly(L-lactide) (mPEG-PLLA), a biodegradable amphiphilic copolymer with a view to improve the entrapment and tuned release of hydrophilic drug gemcitabine. The different mPEG-PLLA copolymers were synthesized with the varying ratios of mPEG and characterized by different techniques namely FTIR and 1 H NMR spectroscopy, solution viscosity, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). Gemcitabine-loaded nanoparticles were prepared using mPEG-PLLA copolymers by two methods i.e. nanoprecipitation and double emulsion solvent evaporation. The nanoprecipitation method showed very less entrapment and polymer solubility in the acetone-water mixture leading to uncontrolled polymer precipitation. The difficulties encountered in the nanoprecipitation method were overcome with the help of the double emulsion (w/o/w) solvent evaporation technique. It has been observed from the results that biodegradable copolymer nanoparticles protect the drug from degradation and also help in controlling the release of encapsulated drug. The properties of nanoparticles can be tailored by varying the composition of mPEG in order to get improved entrapment efficiency and desired drug release. The nanoparticles were assessed for their in vitro cytotoxicity (MTT and FACS) and cellular uptake (fluorescence microscopy) study which showed very promising results. Nanoparticles were also studied for their in vivo release after intravenous administration to Wistar albino rats, which successfully showed controlled drug release for more than 14 days.

  7. Enteric-coated capsules filled with mono-disperse micro-particles containing PLGA-lipid-PEG nanoparticles for oral delivery of insulin.

    Science.gov (United States)

    Yu, Fei; Li, Yang; Liu, Chang Sheng; Chen, Qin; Wang, Gui Huan; Guo, Wei; Wu, Xue E; Li, Dong Hui; Wu, Winston Duo; Chen, Xiao Dong

    2015-04-30

    The success of the oral delivery of insulin (INS) as a therapeutic protein drug would significantly improve the quality of life of diabetic patients who would otherwise receive multiple daily INS injections. The oral delivery of INS, however, is still limited in its delivery efficiency, which could be due to the chemical, enzymatic, and adsorption barriers. In this work, in an attempt to improve the delivery efficiency, the INS-loaded polymer-lipid hybrid nanoparticles (INS-PLGA-lipid-PEG NPs) were designed and constructed through a double-emulsion solvent evaporation technique, followed by formulation of the spherical micro-particles using a spray freeze dryer (SFD). This kind of dryers has a uniquely designed microfluidic aerosol nozzle (MFAN), ensuring the formation of uniform particles. The resulted particles of ∼212 μm could easily be reverted to discrete INS-PLGA-lipid-PEG NPs in an aqueous solution. The INS-PLGA-lipid-PEG NPs created in this work showed a highly negative surface charge, excellent entrapment efficiency (92.3%) and a sustained drug release (∼24 h). Confocal laser scanning microscopy and flow cytometer were used to show that the cellular uptake efficiency for the INS-PLGA-lipid-PEG NPs was more effective than the INS in Caco-2 cells. More importantly, the in vivo pharmacodynamics demonstrated that the orally delivered system induced a prolonged decrease in blood glucose levels among diabetic rats. The relative bioavailability of INS compared with subcutaneous injection in diabetic rats was found to be approximately 12%. These results suggested that the encapsulated INS-PLGA-lipid-PEG NPs are promising and should be investigated further in the near future as an effective INS oral delivery system. Copyright © 2015. Published by Elsevier B.V.

  8. Specific Conjugation of the Hinge Region for Homogeneous Preparation of Antibody Fragment-Drug Conjugate: A Case Study for Doxorubicin-PEG-anti-CD20 Fab' Synthesis.

    Science.gov (United States)

    Zhou, Zhan; Zhang, Jing; Zhang, Yan; Ma, Guanghui; Su, Zhiguo

    2016-01-20

    Conventional preparation strategies for antibody-drug conjugates (ADCs) result in heterogeneous products with various molecular sizes and species. In this study, we developed a homogeneous preparation strategy by site-specific conjugation of the anticancer drug with an antibody fragment. The model drug doxorubicin (DOX) was coupled to the Fab' fragment of anti-CD20 IgG at its permissive sites through a heterotelechelic PEG linker, generating an antibody fragment-drug conjugate (AFDC). Anti-CD20 IgG was digested and reduced specifically with β-mercaptoethylamine to generate the Fab' fragment with two free mercapto groups in its hinge region. Meanwhile, DOX was conjugated with α-succinimidylsuccinate ω-maleimide polyethylene glycol (NHS-PEG-MAL) to form MAL-PEG-DOX, which was subsequently linked to the free mercapto containing Fab' fragment to form a Fab'-PEG-DOX conjugate. The dual site-specific bioconjugation was achieved through the combination of highly selective reduction of IgG and introduction of heterotelechelic PEG linker. The resulting AFDC provides an utterly homogeneous product, with a definite ratio of one fragment to two drugs. Laser confocal microscopy and cell ELISA revealed that the AFDC could accumulate in the antigen-positive Daudi tumor cell. In addition, the Fab'-PEG-DOX retained appreciable targeting ability and improved antitumor activity, demonstrating an excellent therapeutic effect on the lymphoma mice model for better cure rate and significantly reduced side effects.

  9. In vivo therapeutic efficacy of TNFα silencing by folate-PEG-chitosan-DEAE/siRNA nanoparticles in arthritic mice.

    Science.gov (United States)

    Shi, Qin; Rondon-Cavanzo, Elsa-Patricia; Dalla Picola, Isadora Pfeifer; Tiera, Marcio José; Zhang, Xiaoling; Dai, Kerong; Benabdoune, Houda Abir; Benderdour, Mohamed; Fernandes, Julio Cesar

    2018-01-01

    Tumor necrosis factor-alpha (TNFα), a pro-inflammatory cytokine, has been shown to play a role in the pathophysiology of rheumatoid arthritis. Silencing TNFα expression with small interfering RNA (siRNA) is a promising approach to treatment of the condition. Towards this end, our team has developed a modified chitosan (CH) nanocarrier, deploying folic acid, diethylethylamine (DEAE) and polyethylene glycol (PEG) (folate-PEG-CH-DEAE 15 ). The gene carrier protects siRNA against nuclease destruction, its ligands facilitate siRNA uptake via cell surface receptors, and it provides improved solubility at neutral pH with transport of its load into target cells. In the present study, nanoparticles were prepared with siRNA-TNFα, DEAE, and folic acid-CH derivative. Nanoparticle size and zeta potential were verified by dynamic light scattering. Their TNFα-knockdown effects were tested in a murine collagen antibody-induced arthritis model. TNFα expression was examined along with measurements of various cartilage and bone turnover markers by performing histology and microcomputed tomography analysis. We demonstrated that folate-PEG-CH-DEAE 15 /siRNA nanoparticles did not alter cell viability, and significantly decreased inflammation, as demonstrated by improved clinical scores and lower TNFα protein concentrations in target tissues. This siRNA nanocarrier also decreased articular cartilage destruction and bone loss. The results indicate that folate-PEG-CH-DEAE 15 nanoparticles are a safe and effective platform for nonviral gene delivery of siRNA, and their potential clinical applications warrant further investigation.

  10. Synergistic promotion of polar phase crystallization of PVDF by ionic liquid with PEG segment

    Science.gov (United States)

    Xu, Pei; Fu, Weijia; Cui, Zhaopei; Ding, Yunsheng

    2018-06-01

    To investigate the effect of imidazolium ionic liquid with poly(ethylene glycol) segment (IL) on the polar phase crystallization behavior of poly(vinylidene fluoride) (PVDF), a series of PVDF/IL composites were prepared using solution-cast method. The crystallization peak temperature of PVDF composites and the growth speed of samples decrease with increasing of IL. The >CF2 groups in amorphous region are retained and >CF2 groups in crystalline region are liberated by the PEG long soft segments of IL. The intensity of peaks represented as α phase reduces, moreover polar phase content increases with increasing of IL. The interaction between the >CF2 and the imidazolium cation can induce the polar phase, and the interaction between the >CF2 and PEG soft segment can strengthen polar crystalline induction. PVDF/12IL composite can form big γ spherulite circled by β phase.

  11. Acceptability and outcomes of the Percutaneous Endoscopic Gastrostomy (PEG tube placement- patients' and care givers' perspectives

    Directory of Open Access Journals (Sweden)

    Shah Hasnain A

    2006-11-01

    Full Text Available Abstract Background Percutaneous endoscopic gastrostomy tube has now become a preferred option for the long-term nutritional support device for patients with dysphagia. There is a considerable debate about the health issues related to the quality of life of these patients. Our aim of the study was to assess the outcome and perspectives of patients/care givers, about the acceptability of percutaneous endoscopic gastrostomy tube placement. Methods This descriptive analytic study conducted in patients, who have undergone percutaneous endoscopic gastrostomy tube placement during January 1998 till December 2004. Medical records of these patients were evaluated for their demographic characteristics, underlying diagnosis, indications and complications. Telephonic interviews were conducted till March 2005, on a pre-tested questionnaire to address psychological, social and physical performance status, of the health related quality of life issues. Results A total of 191 patients' medical records were reviewed, 120 (63% were males, and mean age was 63 years. Early complication was infection at PEG tube site in 6 (3% patients. In follow up over 365 ± 149 days, late complications (occurring 72 hours later were infection at PEG tube site in 29 (15 % patient and dislodgment/blockage of the tube in 26 (13.6%. Interviews were possible with 126 patients/caretakers. Karnofsky Performance Score of 0, 1, 2, 3 and 4 was found in 13(10%, 18(14%, 21(17%, 29(23% and 45(36% with p-value Conclusion PEG-tube placement was found to be relatively free from serious immediate and long- term complications. Majority of caregivers and patient felt that PEG-tube helped in feeding and prolonging the survival. Studies are needed to assess the real benefit in terms of actual nutritional gain and quality of life in such patients.

  12. Algometry with a clothes peg compared to an electronic pressure algometer: a randomized cross-sectional study in pain patients

    Directory of Open Access Journals (Sweden)

    Marti Elizabeth

    2011-07-01

    Full Text Available Abstract Background Hypersensitivity of the central nervous system is widely present in pain patients and recognized as one of the determinants of chronic pain and disability. Electronic pressure algometry is often used to explore aspects of central hypersensitivity. We hypothesized that a simple pain provocation test with a clothes peg provides information on pain sensitivity that compares meaningfully to that obtained by a well-established electronic pressure algometer. "Clinically meaningful" was defined as a medium (r = 0.3-0.5 or high (r > 0.5 correlation coefficient according to Cohen's conventions. Methods We tested 157 in-patients with different pain types. A calibrated clothes peg was applied for 10 seconds and patients rated the pain intensity on a 0 to 10 numerical rating scale. Pressure pain detection threshold (PPdt and pressure pain tolerance threshold (PPtt were measured with a standard electronic algometer. Both methods were performed on both middle fingers and ear lobes. In a subgroup of 47 patients repeatability (test-retest reliability was calculated. Results Clothes peg values correlated with PPdt values for finger testing with r = -0.54 and for earlobe testing with r = -0.55 (all p-values 0.89, all p-values Conclusions Information on pain sensitivity provided by a calibrated clothes peg and an established algometer correlate at a clinically meaningful level.

  13. Impedance Spectroscopy and FTIR Studies of PEG - Based Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Anji Reddy Polu

    2011-01-01

    Full Text Available Ionic conductivity of poly(ethylene glycol (PEG - ammonium chloride (NH4Cl based polymer electrolytes can be enhanced by incorporating ceramic filler TiO2 into PEG-NH4Cl matrix. The electrolyte samples were prepared by solution casting technique. FTIR studies indicates that the complex formation between the polymer, salt and ceramic filler. The ionic conductivity was measured using impedance spectroscopy technique. It was observed that the conductivity of the electrolyte varies with TiO2 concentration and temperature. The highest room temperature conductivity of the electrolyte of 7.72×10−6 S cm-1 was obtained at 15% by weight of TiO2 and that without TiO2 filler was found to be 9.58×10−7 S cm−1. The conductivity has been improved by 8 times when the TiO2 filler was introduced into the PEG–NH4Cl electrolyte system. The conductance spectra shows two distinct regions: a dc plateau and a dispersive region. The temperature dependence of the conductivity of the polymer electrolytes seems to obey the VTF relation. The conductivity values of the polymer electrolytes were reported and the results were discussed. The imaginary part of dielectric constant (εi decreases with increase in frequency in the low frequency region whereas frequency independent behavior is observed in the high frequency region.

  14. Zn(II)-PEG 300 globules as soft template for the synthesis of hexagonal ZnO micronuts by the hydrothermal reaction method.

    Science.gov (United States)

    Shi, Xixi; Pan, Lingling; Chen, Shuoping; Xiao, Yong; Liu, Qiaoyun; Yuan, Liangjie; Sun, Jutang; Cai, Lintao

    2009-05-19

    Hexagonal ZnO micronuts (HZMNs) have been successfully synthesized with the assistance of poly(ethylene glycol) (PEG) 300 via a hydrothermal method. The structure and morphology of the HZMNs were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). An individual ZnO micronut is revealed as twinned crystals. Time-dependent investigation shows that the growth of HZMNs involves a dissolution-recrystallization process followed by Ostwald ripening, in which is the first formed solid ZnO particles dissolve and transform to HZMNs with hollow structure. PEG 300 has been found to play a crucial role in the growth of this unique hollow structure. TEM observations show that the PEG chains aggregate to globules in water, which then have interaction with the dissolved zinc species to form the globules in a coiled state under hydrothermal conditions. These Zn(II)-PEG 300 globules act as soft template for the growth of HZMNs, and the possible growth mechanism is proposed. The room-temperature photoluminescence (PL) spectrum shows red emission around 612 nm with a full width at half-maximum (fwhm) only about 13 nm.

  15. Distribution of technetium-99m PEG-liposomes during oligofructose-induced laminitis development in horses

    NARCIS (Netherlands)

    Underwood, Claire; Pollitt, Christopher C.; Metselaar, Josbert Maarten; Laverman, Peter; van Bloois, Louis; van den Hoven, Jolanda M.; Storm, Gerrit; van Eps, Andrew W.

    2015-01-01

    Liposomes are phospholipid nanoparticles used for targeted drug delivery. This study aimed to determine whether intravenous liposomes accumulate in lamellar tissue during laminitis development in horses so as to assess their potential for targeted lamellar drug delivery. Polyethylene-glycol (PEG)

  16. Discordant tooth agenesis and peg-shaped in a pair of monozygotic twins: Clinical and molecular study

    Directory of Open Access Journals (Sweden)

    Lívia Azeredo Alves Antunes

    2013-01-01

    Full Text Available The present report aimed to study an uncommon case of a pair of twins that presented a discordant dental phenotype. Family investigation, clinical, radiographic examination and molecular analysis were performed in both girls. Molecular analysis confirmed the monozygosity by deoxyribonucleic acid chip technology. One twin presented tooth agenesis in left upper lateral incisor and peg-shaped on the contra lateral side while the other twin had no dental alterations. The dental casts study employed digital caliper to compare morphological dimensions and showed alteration only in peg-shaped tooth. In conclusion, this study provide support that one or more mutated gene could cause discordances in dental phenotype in these monozygotic twins.

  17. Evaluation of (68)Ga- and (177)Lu-DOTA-PEG4-LLP2A for VLA-4-Targeted PET Imaging and Treatment of Metastatic Melanoma.

    Science.gov (United States)

    Beaino, Wissam; Nedrow, Jessie R; Anderson, Carolyn J

    2015-06-01

    Malignant melanoma is a highly aggressive cancer, and the incidence of this disease is increasing worldwide at an alarming rate. Despite advances in the treatment of melanoma, patients with metastatic disease still have a poor prognosis and low survival rate. New strategies, including targeted radiotherapy, would provide options for patients who become resistant to therapies such as BRAF inhibitors. Very late antigen-4 (VLA-4) is expressed on melanoma tumor cells in higher levels in more aggressive and metastatic disease and may provide an ideal target for drug delivery and targeted radiotherapy. In this study, we evaluated (177)Lu- and (68)Ga-labeled DOTA-PEG4-LLP2A as a VLA-4-targeted radiotherapeutic with a companion PET agent for diagnosis and monitoring metastatic melanoma treatment. DOTA-PEG4-LLP2A was synthesized by solid-phase synthesis. The affinity of (177)Lu- and (68)Ga-labeled DOTA-PEG4-LLP2A to VLA-4 was determined in B16F10 melanoma cells by saturation binding and competitive binding assays, respectively. Biodistribution of the LLP2A conjugates was determined in C57BL/6 mice bearing B16F10 subcutaneous tumors, while PET/CT imaging was performed in subcutaneous and metastatic models. (177)Lu-DOTA-PEG4-LLP2A showed high affinity to VLA-4 with a Kd of 4.1 ± 1.5 nM and demonstrated significant accumulation in the B16F10 melanoma tumor after 4 h (31.5 ± 7.8%ID/g). The tumor/blood ratio of (177)Lu-DOTA-PEG4-LLP2A was highest at 24 h (185 ± 26). PET imaging of metastatic melanoma with (68)Ga-DOTA-PEG4-LLP2A showed high uptake in sites of metastases and correlated with bioluminescence imaging of the tumors. These data demonstrate that (177)Lu-DOTA-PEG4-LLP2A has potential as a targeted therapeutic for treating melanoma as well as other VLA-4-expressing tumors. In addition, (68)Ga-DOTA-PEG4-LLP2A is a readily translatable companion PET tracer for imaging of metastatic melanoma.

  18. Is survival improved by the use of NIV and PEG in amyotrophic lateral sclerosis (ALS? A post-mortem study of 80 ALS patients.

    Directory of Open Access Journals (Sweden)

    Christian Burkhardt

    Full Text Available Non-invasive ventilation (NIV and percutaneous gastrostomy (PEG are guideline-recommended interventions for symptom management in amyotrophic lateral sclerosis (ALS. Their effect on survival is controversial and the impact on causes of death is unknown.To investigate the effect of NIV and PEG on survival and causes of death in ALS patients.Eighty deceased ALS patients underwent a complete post mortem analysis for causes of death between 2003 and 2015. Forty-two of these patients consented for genetic testing. Effects of NIV and PEG on survival and causes of death were analyzed in a multivariable Cox proportional hazard regression.Six patients, who requested assisted suicide causing drug-induced hypoxia, were excluded from final analysis. Respiratory failure was the main cause of death in 72 out of 74 patients. Fifteen out of 74 died of aspiration pneumonia 23/74 of bronchopneumonia and 8/74 of a combination of aspiration pneumonia and bronchopneumonia. Twenty died of hypoxia without concomitant infection, and six patients had pulmonary embolism alone or in combination with pneumonia. NIV (p = 0.01 and PEG (p<0.01 had a significant impact on survival. In patients using NIV bronchopneumonia was significantly more frequent (p <0.04 compared to non-NIV patients. This effect was even more pronounced in limb onset patients (p<0.002. Patients with C9orf72 hexanucleotide repeat expansions showed faster disease progression and shorter survival (p = 0.01.The use of NIV and PEG prolongs survival in ALS. This study supports current AAN and EFNS guidelines which recommend NIV and PEG as a treatment option in ALS. The risk of bronchopneumonia as cause of death may be increased by NIV.

  19. Use of Powder PEG-3350 as a Sole Bowel Preparation: Clinical Case Series of 245 Patients.

    Science.gov (United States)

    Arora, Manish; Okolo, Patrick I

    2008-07-01

    To assess the efficacy of low-volume powder polyethylene glycol (PEG)-3350 as a sole bowel preparation for colonoscopy. This case series examined 245 consecutive patients (a mixture of inpatients and outpatients undergoing screening colonoscopy) at a hospital endoscopy center over a 2-year period. The patients received powder PEG-3350 in the amount of 204 g dissolved in 32 oz of water and taken in 3 divided doses 1 hour apart with 8 oz of water in between each dose. Colon preparation scores (CPS) were used to assess the quality of colon cleansing. The results obtained from the 245 patients were collated and compared to those of patients receiving sodium phosphate, the historical control. The mean CPS was calculated to be 3.43, with a standard deviation of 1.12. Of the 245 patients, 92 were scored with a grade of 4, and 5 patients had incomplete colonoscopies secondary to failure of bowel preparation (CPS=0). Among the remaining patients, 22 and 26 were graded as poor (CPS=1) or fair (CPS=2) bowel preparations, respectively. The low-volume powder PEG-3350 formula used in our case series showed effective colon cleansing and may be considered for use as a sole bowel preparation.

  20. Activity coefficients of LiCl in (PEG 4000 + water) at T = (288.15, 298.15, and 308.15) K

    International Nuclear Information System (INIS)

    Morales, Jaime W.; Galleguillos, Hector R.; Graber, Teofilo A.; Hernandez-Luis, Felipe

    2010-01-01

    The electromotive force of the cell containing two ion-selective electrodes (ISE), Na-ISE|LiCl(m),PEG4000(w),H 2 O(1-w)|Cl-ISE has been measured at temperatures of (288.15, 298.15, and 308.15) K as a function of the mass fraction of PEG 4000 (w) in the mixture. w was varied between 0 and 0.25 in 0.05-unit steps and the molality of the electrolyte (m) was between c.a. (0.03 and 5.8) mol . kg -1 . The values of the standard electromotive force, E 0 , were determined using routine methods of extrapolation, together with extended Debye-Hueckel and Pitzer equations. The results obtained produced good internal consistency for all the temperatures studied. Once E 0 was determined, the mean ionic activity coefficients for LiCl, the Gibbs free energy of transfer from the water to (PEG 4000 + water), and the primary LiCl hydration number were calculated.

  1. Activity coefficients of LiCl in (PEG 4000 + water) at T = (288.15, 298.15, and 308.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Jaime W.; Galleguillos, Hector R.; Graber, Teofilo A. [Centro de Investigacion Cientifico y Tecnologico para la Mineria, Departamento de Ingenieria Quimica, Universidad de Antofagasta (Chile); Hernandez-Luis, Felipe, E-mail: ffhelu@ull.e [Departamento de Quimica Fisica, Universidad de La Laguna, Tenerife (Spain)

    2010-10-15

    The electromotive force of the cell containing two ion-selective electrodes (ISE), Na-ISE|LiCl(m),PEG4000(w),H{sub 2}O(1-w)|Cl-ISE has been measured at temperatures of (288.15, 298.15, and 308.15) K as a function of the mass fraction of PEG 4000 (w) in the mixture. w was varied between 0 and 0.25 in 0.05-unit steps and the molality of the electrolyte (m) was between c.a. (0.03 and 5.8) mol . kg{sup -1}. The values of the standard electromotive force, E{sup 0}, were determined using routine methods of extrapolation, together with extended Debye-Hueckel and Pitzer equations. The results obtained produced good internal consistency for all the temperatures studied. Once E{sup 0} was determined, the mean ionic activity coefficients for LiCl, the Gibbs free energy of transfer from the water to (PEG 4000 + water), and the primary LiCl hydration number were calculated.

  2. Nickel electroplating on copper pre-activated Al alloy in the electrolyte containing PEG1000 as an additive

    Science.gov (United States)

    Guan, Jie; Wang, Jinwei; Zhang, Dawei

    2018-06-01

    Ni coatings are prepared on Cu-pretreated anodic Al alloy by electroplating technique in environment-friendly electrolytes with PEG1000 as an additive. Some defects like pores, cracks and even uncovered areas are observed for the sample of the Cu-pretreated anodic Al alloy, and these defects seem to be remedied with the following Ni electroplating as observed from their SEM images; while the covering effect of Ni onto the Cu layer is rather limited as judged by their corrosion current data of polarization test. After adding PEG1000 in the Ni electroplating electrolyte, the obtained coating surfaces are seen smoother and thicker; and most of the tiny particles are seen closely packed together with some bigger particles on them. The diffusion of nickel particles into copper layer are confirmed by the line and mapping mode of EDS element analysis for the Ni-Cu composite coating. Their much lower corrosion current density ( I corr) and higher micro-hardness support the fact that the addition of PEG1000 in Ni plating electrolyte has a function of promoting the refinement of Ni particles and the formation of more compacter, thicker and smoother Ni-Cu composite coating.

  3. Synthesis of mesoporous β-Ga2O3 nanorods using PEG as template: preparation, characterization and photocatalytic properties.

    Science.gov (United States)

    Zhao, Weirong; Yang, Yong; Hao, Rui; Liu, Feifei; Wang, Yan; Tan, Min; Tang, Jing; Ren, Daqing; Zhao, Dongye

    2011-09-15

    Mesoporous wide bandgap semiconductors offer high photocatalytic oxidation and mineralization activities. In this study, mesoporous β-Ga(2)O(3) diamond nanorods with 200-300 nm in diameter and 1.0-1.2 μm in length were synthesized via a urea-based hydrothermal method using polyethylene glycol (PEG) as template agent. The UV photocatalytic oxidation activity of β-Ga(2)O(3) for gaseous toluene was evaluated, and 7 kinds of intermediates were monitored online by a proton transfer reaction mass spectrometry. Photoluminescence spectra manifested that the dosage and molecular weight of PEG are crucial for formation of vacancies and photocatalytic oxidation activities. A PEG-assisted hydrothermal formation mechanism of mesoporous β-Ga(2)O(3) diamond nanorods was proposed. Based on the health risk influence index (η) of the intermediates, the calculated health risks revealed that the β-Ga(2)O(3) nanorods with a η value of 9.6 are much safer than TiO(2) (η = 17.6). Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Effect of miR-146a/bFGF/PEG-PEI Nanoparticles on Inflammation Response and Tissue Regeneration of Human Dental Pulp Cells

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2016-01-01

    Full Text Available Introduction. Inflammation in dental pulp cells (DPCs initiated by Lipopolysaccharide (LPS results in dental pulp necrosis. So far, whether there is a common system regulating inflammation response and tissue regeneration remains unknown. miR-146a is closely related to inflammation. Basic fibroblast growth factor (bFGF is an important regulator for differentiation. Methods. To explore the effect of miR-146a/bFGF on inflammation and tissue regeneration, polyethylene glycol-polyethyleneimine (PEG-PEI was synthesized, and physical characteristics were analyzed by dynamic light scattering and gel retardation analysis. Cell absorption, transfection efficiency, and cytotoxicity were assessed. Alginate gel was combined with miR-146a/PEG-PEI nanoparticles and bFGF. Drug release ratio was measured by ultraviolet spectrophotography. Proliferation and odontogenic differentiation of DPCs with 1 μg/mL LPS treatment were determined. Results. PEG-PEI prepared at N/P 2 showed complete gel retardation and smallest particle size and zeta potential. Transfection efficiency of PEG-PEI was higher than lipo2000. Cell viability decreased as N/P ratio increased. Drug release rate amounted to 70% at the first 12 h and then maintained slow release afterwards. Proliferation and differentiation decreased in DPCs with LPS treatment, whereas they increased in miR-146a/bFGF gel group. Conclusions. PEG-PEI is a promising vector for gene therapy. miR-146a and bFGF play critical roles in inflammation response and tissue regeneration of DPCs.

  5. Composite biomaterials with chemical bonding between hydroxyapatite filler particles and PEG/PBT copolymer matrix

    NARCIS (Netherlands)

    Liu, Qing; de Wijn, J.R.; van Blitterswijk, Clemens

    1998-01-01

    In an effort to make composites from hydroxyapatite and a PEG/PBT copolymer (PolyactiveTM 70/30), chemical linkages were introduced between the filler particles and polymer matrix using hexamethylene diisocyanate as a coupling agent. Infrared spectra (IR) and thermal gravimetric analysis (TGA)

  6. Comparison of the gravimetric, phenol red, and 14C-PEG-3350 methods to determine water absorption in the rat single-pass intestinal perfusion model.

    Science.gov (United States)

    Sutton, S C; Rinaldi, M T; Vukovinsky, K E

    2001-01-01

    This study was undertaken to determine whether the gravimetric method provided an accurate measure of water flux correction and to compare the gravimetric method with methods that employ nonabsorbed markers (eg, phenol red and 14C-PEG-3350). Phenol red,14C-PEG-3350, and 4-[2-[[2-(6-amino-3-pyridinyl)-2-hydroxyethyl]amino]ethoxy]-, methyl ester, (R)-benzene acetic acid (Compound I) were co-perfused in situ through the jejunum of 9 anesthetized rats (single-pass intestinal perfusion [SPIP]). Water absorption was determined from the phenol red,14C-PEG-3350, and gravimetric methods. The absorption rate constant (ka) for Compound I was calculated. Both phenol red and 14C-PEG-3350 were appreciably absorbed, underestimating the extent of water flux in the SPIP model. The average +/- SD water flux microg/h/cm) for the 3 methods were 68.9 +/- 28.2 (gravimetric), 26.8 +/- 49.2 (phenol red), and 34.9 +/- 21.9 (14C-PEG-3350). The (average +/- SD) ka for Compound I (uncorrected for water flux) was 0.024 +/- 0.005 min(-1). For the corrected, gravimetric method, the average +/- SD was 0.031 +/- 0.001 min(-1). The gravimetric method for correcting water flux was as accurate as the 2 "nonabsorbed" marker methods.

  7. Characteristics of W/O emulsions containing polymeric emulsifier PEG 30-dipolyhydroxystearate

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    Milinković Jelena R.

    2016-01-01

    Full Text Available Water-in-oil (W/O emulsions are dispersed systems which are often used in the pharmaceutical, cosmetic and food industries as products, or as carriers of active substances. It is well known that they are very unstable, so that selection of the emulsifier and properties of the oil and water phase are main factors affecting their stability. The aim of this paper was to examine the possibility of application of a lipophilic, polymeric emulsifier, PEG 30-dipolyhydroxystearate (CithrolTM DPHS, for stabilization of W/O emulsions. Behaviour of the emulsifier at W/O interfaces was determined by means of tensiometry. A series of emulsions were prepared with 20% (w/w of water and different types of oil. Droplet size, droplet size distribution, viscosity, and sedimentation stability during 30 days of storage at room temperature of the emulsions prepared with paraffin oil, olive oil, grape seed oil, and medium-chain triglycerides, stabilized with 1% CithrolTM DPHS, were determined. All investigated emulsions were stable for 30 days, except the one prepared with paraffin oil. The results of this study confirmed that PEG 30-dipolyhydroxylstearate is a good emulsifier and stabilizer of W/O emulsions which contain different types of oil. [Projekat Ministarstva nauke Republike Srbije, br. III46010

  8. Halopriming of seeds imparts tolerance to NaCl and PEG induced stress in Vigna radiata (L.) Wilczek varieties.

    Science.gov (United States)

    Jisha, K C; Puthur, Jos T

    2014-07-01

    The investigation was carried out to study the effect of halopriming on NaCl and polyethylene glycol-6000 (PEG-6000) induced stress tolerance potential of three Vigna radiata (L.) Wilczek varieties, with varied abiotic stress tolerance potential. Halopriming is a seed priming technique in which the seeds were soaked in various salt solutions (in this study NaCl was used). The results of the study indicated that the application of stresses (both NaCl and PEG) induced retardation of growth attributes (measured in terms of shoot length, fresh weight, dry weight) and decrease in physiological attributes like total chlorophyll content, metabolites, photosynthetic and mitochondrial activity of the seedlings in all three V. radiata (L.) varieties. However, halopriming of the seeds could reduce the extent of decrease in these biological attributes. NaCl and PEG stress also caused increase in MDA content (a product of membrane lipid peroxidation) in all the varieties studied and this increase was significantly minimized under halopriming. From the present investigation it was evident that among the green gram varieties studied, Pusa Vishal, a NaCl tolerant variety showed enhanced tolerance to NaCl and PEG induced stress, when the seeds were subjected to halopriming followed by Pusa Ratna (stress sensitive variety). Pusa 9531 (drought tolerant variety) also showed positive halopriming effects but it was less significant when compared to other two varieties. It could be concluded that halopriming improved the drought and salinity stress tolerance potential of all varieties and it was significantly higher in the Pusa Vishal as compared to Pusa 9531 and Pusa Ratna.

  9. Codelivery of SH-aspirin and curcumin by mPEG-PLGA nanoparticles enhanced antitumor activity by inducing mitochondrial apoptosis

    Directory of Open Access Journals (Sweden)

    Zhou L

    2015-08-01

    Full Text Available Lin Zhou,1,2,* Xingmei Duan,1,2,* Shi Zeng,1 Ke Men,1 Xueyan Zhang,1 Li Yang,1 Xiang Li1 1State Key Laboratory of Biotherapy, Cancer Center and Department of Urology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China; 2Sichuan Food and Drug Safety Monitoring and Review of Certification, Adverse Reaction Monitoring Center, Drug Abuse Monitoring Center, Chengdu, People’s Republic of China *These authors contributed equally to this work Abstract: Natural product curcumin (Cur and H2S-releasing prodrug SH-aspirin (SH-ASA are potential anticancer agents with diverse mechanisms, but their clinical application prospects are restricted by hydrophobicity and limited efficiency. In this work, we coencapsulated SH-ASA and Cur into methoxy poly(ethylene glycol-poly (lactide-coglycolide (mPEG-PLGA nanoparticles through a modified oil-in-water single-emulsion solvent evaporation process. The prepared SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles had a mean particle size of 122.3±6.8 nm and were monodispersed (polydispersity index =0.179±0.016 in water, with high drug-loading capacity and stability. Intriguingly, by treating with SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles, obvious synergistic anticancer effects on ES-2 and SKOV3 human ovarian carcinoma cells were observed in vitro, and activation of the mitochondrial apoptosis pathway was indicated. Our results demonstrated that SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles could have potential clinical advantages for the treatment of ovarian cancer. Keywords: drug delivery, cancer therapy, ovarian cancer, synergistic effect

  10. Ternary polyplex micelles with PEG shells and intermediate barrier to complexed DNA cores for efficient systemic gene delivery.

    Science.gov (United States)

    Li, Junjie; Chen, Qixian; Zha, Zengshi; Li, Hui; Toh, Kazuko; Dirisala, Anjaneyulu; Matsumoto, Yu; Osada, Kensuke; Kataoka, Kazunori; Ge, Zhishen

    2015-07-10

    Simultaneous achievement of prolonged retention in blood circulation and efficient gene transfection activity in target tissues has always been a major challenge hindering in vivo applications of nonviral gene vectors via systemic administration. Herein, we constructed novel rod-shaped ternary polyplex micelles (TPMs) via complexation between the mixed block copolymers of poly(ethylene glycol)-b-poly{N'-[N-(2-aminoethyl)-2-aminoethyl]aspartamide} (PEG-b-PAsp(DET)) and poly(N-isopropylacrylamide)-b-PAsp(DET) (PNIPAM-b-PAsp(DET)) and plasmid DNA (pDNA) at room temperature, exhibiting distinct temperature-responsive formation of a hydrophobic intermediate layer between PEG shells and pDNA cores through facile temperature increase from room temperature to body temperature (~37 °C). As compared with binary polyplex micelles of PEG-b-PAsp(DET) (BPMs), TPMs were confirmed to condense pDNA into a more compact structure, which achieved enhanced tolerability to nuclease digestion and strong counter polyanion exchange. In vitro gene transfection results demonstrated TPMs exhibiting enhanced gene transfection efficiency due to efficient cellular uptake and endosomal escape. Moreover, in vivo performance evaluation after intravenous injection confirmed that TPMs achieved significantly prolonged blood circulation, high tumor accumulation, and promoted gene expression in tumor tissue. Moreover, TPMs loading therapeutic pDNA encoding an anti-angiogenic protein remarkably suppressed tumor growth following intravenous injection into H22 tumor-bearing mice. These results suggest TPMs with PEG shells and facilely engineered intermediate barrier to inner complexed pDNA have great potentials as systemic nonviral gene vectors for cancer gene therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Docetaxel-loaded PLGA and PLGA-PEG nanoparticles for intravenous application: pharmacokinetics and biodistribution profile.

    Science.gov (United States)

    Rafiei, Pedram; Haddadi, Azita

    2017-01-01

    Docetaxel is a highly potent anticancer agent being used in a wide spectrum of cancer types. There are important matters of concern regarding the drug's pharmacokinetics related to the conventional formulation. Poly(lactide- co -glycolide) (PLGA) is a biocompatible/biodegradable polymer with variable physicochemical characteristics, and its application in human has been approved by the United States Food and Drug Administration. PLGA gives polymeric nanoparticles with unique drug delivery characteristics. The application of PLGA nanoparticles (NPs) as intravenous (IV) sustained-release delivery vehicles for docetaxel can favorably modify pharmacokinetics, biofate, and pharmacotherapy of the drug in cancer patients. Surface modification of PLGA NPs with poly(ethylene glycol) (PEG) can further enhance NPs' long-circulating properties. Herein, an optimized fabrication approach has been used for the preparation of PLGA and PLGA-PEG NPs loaded with docetaxel for IV application. Both types of NP formulations demonstrated in vitro characteristics that were considered suitable for IV administration (with long-circulating sustained-release purposes). NP formulations were IV administered to an animal model, and docetaxel's pharmacokinetic and biodistribution profiles were determined and compared between study groups. PLGA and PEGylated PLGA NPs were able to modify the pharmacokinetics and biodistribution of docetaxel. Accordingly, the mode of changes made to pharmacokinetics and biodistribution of docetaxel is attributed to the size and surface properties of NPs. NPs contributed to increased blood residence time of docetaxel fulfilling their role as long-circulating sustained-release drug delivery systems. Surface modification of NPs contributed to more pronounced docetaxel blood concentration, which confirms the role of PEG in conferring long-circulation properties to NPs.

  12. Discovery of Water at High Spectral Resolution in the Atmosphere of 51 Peg b

    Science.gov (United States)

    Birkby, J. L.; de Kok, R. J.; Brogi, M.; Schwarz, H.; Snellen, I. A. G.

    2017-03-01

    We report the detection of water absorption features in the day side spectrum of the first-known hot Jupiter, 51 Peg b, confirming the star-planet system to be a double-lined spectroscopic binary. We use high-resolution (R≈ 100,000), 3.2 μ {{m}} spectra taken with CRIRES/VLT to trace the radial-velocity shift of the water features in the planet’s day side atmosphere during 4 hr of its 4.23 day orbit after superior conjunction. We detect the signature of molecular absorption by water at a significance of 5.6σ at a systemic velocity of {V}{sys}=-33+/- 2 km s-1, coincident with the 51 Peg host star, with a corresponding orbital velocity {K}{{P}}={133}-3.5+4.3 km s-1. This translates directly to a planet mass of {M}{{p}}={0.476}-0.031+0.032 {M}{{J}}, placing it at the transition boundary between Jovian and Neptunian worlds. We determine upper and lower limits on the orbital inclination of the system of 70^\\circ bearing molecules of the planet, including methane and carbon dioxide. The atmosphere is non-inverted in the temperature-pressure region probed by these observations. The deepest absorption lines reach an observed relative contrast of 0.9× {10}-3 with respect to the host star continuum flux at an angular separation of 3 milliarcseconds. This work is consistent with a previous tentative report of K-band molecular absorption for 51 Peg b by Brogi et al.

  13. Physical-chemical characterization of different hydrogels Formulations

    International Nuclear Information System (INIS)

    Rodriguez, Y.; Romero, M.; Soler, I.; Saldivar, D.

    2001-01-01

    They were carried out swelling studies at 37 0C of different hydrogels formulations whose composition was the following one: 3% PEG-1000, 1% Agar and concentrations of PVP and NVP 7, 10 and 14% and a maximum thickness of 2 mm, this formulations were irradiated to 25 kGy in a self-shield irradiator of 60Co and the same time studies of the mechanical properties. It was obtained that the hydrogels of PVP absorbs more water than those of NVP. It was described pseudo-Fickian s kinetic whose exponent diffusional is in the following range: 0.5 0.6

  14. FORMULATION AND EVALUATION OF MEFENAMIC ACID SOLID DISPERSIONS USING PEG-4000

    OpenAIRE

    Shaik Jamal Shariff; Shaik Saleem; Alaparthi Naga Pavan Kumar; Bachupally Ajay Kumar; Punuru Madhusudhan

    2013-01-01

    Mefenamic acid (MA) solid Dispersions were prepared employing methanol as a common solvent using PEG-4000 as a drug carrier with two different techniques namely, melting method and solvent evaporation in varied ratios. The prepared solid dispersions were evaluated and compared with that of pure drug (mefenamic acid) in respect to the dissolution rate and dissolution efficiency. It is noted that solid dispersions of mefenamic acid showed a remarkable increase in dissolution rate and dissolutio...

  15. PEG-b-(PELG-g-PLL nanoparticles as TNF-α nanocarriers: potential cerebral ischemia/reperfusion injury therapeutic applications

    Directory of Open Access Journals (Sweden)

    Xu G

    2017-03-01

    Full Text Available Guangtao Xu,1,2 Huan Gu,1,3 Bo Hu,4 Fei Tong,2 Daojun Liu,1 Xiaojun Yu,1 Yongxia Zheng,1,2 Jiang Gu1 1Department of Pathology and Chemistry, Provincial Key Laboratory of Infectious Diseases and Immunopathology, Collaborative and Creative Center, Molecular Diagnosis and Personalized Medicine, Shantou University Medical College, Shantou, Guangdong, 2Department of Pathology, Provincial Key Discipline of Pharmacology, Jiaxing University Medical College, Jiaxing, Zhejiang, People’s Republic of China; 3Department of Physics, University of Maryland, College Park, Annapolis, MD, USA; 4Department of Chemical Pathology, Jiaxing Hospital of Traditional Chinese Medicine, Zhejiang Chinese Medical University, Jiaxing, Zhejiang, People’s Republic of China Abstract: Brain ischemia/reperfusion (I/R injury (BI/RI is a leading cause of death and disability worldwide. However, the outcome of pharmacotherapy for BI/RI remains unsatisfactory. Innovative approaches for enhancing drug sensitivity and recovering neuronal activity in BI/RI treatment are urgently needed. The purpose of this study was to evaluate the protective effects of tumor necrosis factor (TNF-α-loaded poly(ethylene glycol-b-(poly(ethylenediamine l-glutamate-g-poly(l-lysine (TNF-α/PEG-b-(PELG-g-PLL nanoparticles on BI/RI. The particle size of PEG-b-(PELG-g-PLL and the loading and release rates of TNF-α were determined. The nanoparticle cytotoxicity was evaluated in vitro using rat cortical neurons. Sprague Dawley rats were preconditioned with free TNF-α or TNF-α/PEG-b-(PELG-g-PLL polyplexes and then subjected to 2 hours ischemia and 22 hours reperfusion. Brain edema was assessed using the brain edema ratio, and the antioxidative activity was assessed by measuring the superoxide dismutase (SOD activity and the malondialdehyde (MDA content in the brain tissue. We further estimated the inflammatory activity and apoptosis level by determining the levels of interleukin-4 (IL-4, IL-6, IL-8, IL-10

  16. Fast programming of peg-in-hole actions by human demonstration

    DEFF Research Database (Denmark)

    Yang, Yang; Lin, Linglong; Song, Y. T.

    2014-01-01

    Peg-in-Hole actions play an important role in industrial assembly. In this paper, we present a system which performs such actions after learning by human demonstration. Strategies for getting robust human-demonstrated PiH trajectories are investigated, and a number of PiH experiments are conducte...... to verify the performance of the proposed approach. The results show that our approach leads to a high PiH success rate and allows the robot to fine-tune the PiH trajectories to achieve faster performance....

  17. A comparison inhibitory effects of cisplatin and MNPs-PEG-cisplatin on the adhesion capacity of bone metastatic breast cancer.

    Science.gov (United States)

    Mokhtari, Mohammad Javad; Koohpeima, Fatemeh; Mohammadi, Hadi

    2017-10-01

    To date, high mortality in women due to malignancy breast cancer related to the metastasis to the bone is a significant challenge. As, magnetic nanoparticles (MNPs) conjugated with the biocompatible polymers was employed for the delivery of some hydrophobic anticancer agents, the main aim of the current research was to assess whether cisplatin-loaded MNPs enhanced the anticancer effect of free cisplatin in breast cancer cells. MNPs decorated with PEG were synthesized by an improved coprecipitation technique, and then cisplatin was loaded onto the MNPs via a simple mixing method. Afterward, its morphology, size, chemical structure, magnetic property, hydrodynamic diameter, zeta potential, and crystal structure were characterized by scanning and transmittance electron microscopy, Fourier transforms infrared spectroscopy, vibrating sample magnetometer, dynamic light scattering, and X-ray powder diffraction and flame atomic absorption spectroscopy respectively. Additionally, the effects of cisplatin and MNPs-PEG-cisplatin on viability, migration and adhesion capacity of T47D cells were investigated by evaluating α2-integrin and β1-integrin; mRNAs were assessed by real-time RT-PCR. Consequently, the in vitro assay results showed a considerable dose-dependent inhibitory effect of cisplatin and MNPs-PEG-cisplatin on proliferation, migration, and adhesion of T47D cells. Finally, current research was shown that MNPs-PEG-cisplatin strongly increased anticancer effects compared with free cisplatin in the T47D cell line. © 2017 John Wiley & Sons A/S.

  18. Design and evaluation of mPEG-PLA micelles functionalized with drug-interactive domains as improved drug carriers for docetaxel delivery.

    Science.gov (United States)

    Qi, Dingqing; Gong, Feirong; Teng, Xin; Ma, Mingming; Wen, Huijing; Yuan, Weihao; Cheng, Yi; Lu, Chong

    2017-10-01

    Polymeric micelles are very attractive drug delivery systems for hydrophobic agents, owing to their readily tailorable chemical structure and ease for scale-up preparation. However, the intrinsic poor stability of drug-loaded micelles presents one of the major challenges for most micellar systems in the translation to clinical applications. In this study, a simple, well-defined, and easy-to-scale up 9-Fluorenylmethoxycarbonyl (Fmoc) and tert-butoxycarbonyl (Boc) containing lysine dendronized mPEG-PLA (mPEG-PLA-Lys(FB) 2 ) micellar formulation was designed and prepared for docetaxel (DTX) delivery, in an effort to improve the stability of the micelles, and its physicochemical properties, pharmacokinetics, and anti-tumor efficacy against SKOV-3 ovarian cancer were evaluated. MPEG-PLA-Lys(FB) 2 was synthesized via a three-step synthetic route, and it actively interacted with DTX in aqueous media to form stable micelles with small particle sizes (~17-19 nm) and narrow size distribution (PI PLA-Lys(FB) 2 micelles achieved delayed and sustained release manner of DTX in comparison with mPEG-PLA micelles. Further in vivo xenograft tumor model in nude mice DTX/mPEG-PLA-Lys(FB) 2 micelles demonstrated significantly higher inhibitory effect on tumor growth than the marketed formulation Taxotere. Thus, our system may hold promise as a simple and effective delivery system for DTX with a potential for translation into clinical study.

  19. Effect of Extreme Cold Treatment on Morphology and Behavior of Hydrogels and Microgels (Poster Session)

    Science.gov (United States)

    2017-08-20

    capable of better managing a soldier’s comfort by regulating moisture and thermal properties • Hydrogel or microgel textile coatings are of interest...to understand the effect of cold temperature ( down to -80 ° C) on hydrogel and microgel particles properties and response to thermal stimuli • We...determine water uptake post freezing Sweat EFFECTS ON WATER UPTAKE PRELIMINARY MICROGEL THERMAL STUDIES MORPHOLOGY POST FREEZING PAA PEG PNIPAAm BEFORE AFTER

  20. Improved Anticancer Effect of Magnetite Nanocomposite Formulation of GALLIC Acid (Fe₃O₄-PEG-GA) Against Lung, Breast and Colon Cancer Cells.

    Science.gov (United States)

    Rosman, Raihana; Saifullah, Bullo; Maniam, Sandra; Dorniani, Dena; Hussein, Mohd Zobir; Fakurazi, Sharida

    2018-02-02

    Lung cancer, breast cancer and colorectal cancer are the most prevalent fatal types of cancers globally. Gallic acid (3,4,5-trihydroxybenzoic acid) is a bioactive compound found in plants and foods, such as white tea, witch hazel and it has been reported to possess anticancer, antioxidant and anti-inflammatory properties. In this study we have redesigned our previously reported anticancer nanocomposite formulation with improved drug loading based on iron oxide magnetite nanoparticles coated with polyethylene glycol and loaded with anticancer drug gallic acid (Fe₃O₄-PEG-GA). The in vitro release profile and percentage drug loading were found to be better than our previously reported formulation. The anticancer activity of pure gallic acid (GA), empty carrier (Fe₃O₄-PEG) nanocarrier and of anticancer nanocomposite (Fe₃O₄-PEG-GA) were screened against human lung cancer cells (A549), human breast cancer cells (MCF-7), human colon cancer cells (HT-29) and normal fibroblast cells (3T3) after incubation of 24, 48 and 72 h using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay. The designed formulation (Fe₃O₄-PEG-GA) showed better anticancer activity than free gallic acid (GA). The results of the in vitro studies are highly encouraging to conduct the in vivo studies.