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Sample records for monomethoxy polyethylene glycol

  1. Thermo-sensitive transition of monomethoxy poly(ethylene glycol)-block-poly(trimethylene carbonate) films to micellar-like nanoparticles

    NARCIS (Netherlands)

    Zhang, Zheng; Grijpma, Dirk W.; Feijen, Jan

    2006-01-01

    Monomethoxy poly(ethylene glycol)-block-poly(trimethylene carbonate) (mPEG3–PTMC11, Mn of mPEG = 3.1 × 103 and Mn of PTMC = 10.8 × 103 g/mol) was synthesized by ring-opening polymerization of TMC using mPEG3 as an initiator and stannous octoate as a catalyst. The block copolymer has a broad melting

  2. Preparation and characterization of monomethoxy poly(ethylene glycol-poly(ε-caprolactone micelles for the solubilization and in vivo delivery of luteolin

    Directory of Open Access Journals (Sweden)

    Qiu JF

    2013-08-01

    Full Text Available Jin-Feng Qiu,1 Xiang Gao,1,2 Bi-Lan Wang,1 Xia-Wei Wei,1 Ma-Ling Gou,1 Ke Men,1 Xing-Yu Liu,1 Gang Guo,1 Zhi-Yong Qian,1 Mei-Juan Huang1 1Department of Thoracic Oncology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital and Medical School, Sichuan University, Chengdu, People’s Republic of China; 2Medical School and Department of Pathophysiology, College of Preclinical and Forensic Medical Sciences, Sichuan University, Chengdu, People’s Republic of China Abstract: Luteolin (Lu is one of the flavonoids with anticancer activity, but its poor water solubility limits its use clinically. In this work, we used monomethoxy poly(ethylene glycol-poly(ε-caprolactone (MPEG-PCL micelles to encapsulate Lu by a self-assembly method, creating a water-soluble Lu/MPEG-PCL micelle. These micelles had a mean particle size of 38.6 ± 0.6 nm (polydispersity index = 0.16 ± 0.02, encapsulation efficiency of 98.32% ± 1.12%, and drug loading of 3.93% ± 0.25%. Lu/MPEG-PCL micelles could slowly release Lu in vitro. Encapsulation of Lu in MPEG-PCL micelles improved the half-life (t½; 152.25 ± 49.92 versus [vs] 7.16 ± 1.23 minutes, P = 0.007, area under the curve (0–t (2914.05 ± 445.17 vs 502.65 ± 140.12 mg/L/minute, P = 0.001, area under the curve (0–∞ (2989.03 ± 433.22 vs 503.81 ± 141.41 mg/L/minute, P = 0.001, and peak concentration (92.70 ± 11.61 vs 38.98 ± 7.73 mg/L, P = 0.003 of Lu when the drug was intravenously administered at a dose of 30 mg/kg in rats. Also, Lu/MPEG-PCL micelles maintained the cytotoxicity of Lu on 4T1 breast cancer cells (IC50 = 6.4 ± 2.30 µg/mL and C-26 colon carcinoma cells (IC50 = 12.62 ± 2.17 µg/mL in vitro. These data suggested that encapsulation of Lu into MPEG-PCL micelles created an aqueous formulation of Lu with potential anticancer effect. Keywords: luteolin, micelle, MPEG-PCL, cancer therapy

  3. Polyethylene Glycol 3350

    Science.gov (United States)

    Polyethylene glycol 3350 is used to treat occasional constipation. Polyethylene glycol 3350 is in a class of medications called ... Polyethylene glycol 3350 comes as a powder to be mixed with a liquid and taken by mouth. It ...

  4. Polyethylene Glycol Propionaldehydes

    Science.gov (United States)

    Harris, Joe M.; Sedaghat-Herati, Mohammad R.; Karr, Laurel J.

    1992-01-01

    New class of compounds derived from polyethylene glycol (PEG's) namely, PEG-propionaldehydes, offers two important advantages over other classes of PEG aldehyde derivatives: compounds exhibit selective chemical reactivity toward amino groups and are stable in aqueous environment. PEG's and derivatives used to couple variety of other molecules, such as, to tether protein molecules to surfaces. Biotechnical and biomedical applications include partitioning of two phases in aqueous media; immobilization of such proteins as enzymes, antibodies, and antigens; modification of drugs; and preparation of protein-rejecting surfaces. In addition, surfaces coated with PEG's and derivatives used to control wetting and electroosmosis. Another potential application, coupling to aminated surfaces.

  5. Synthesis, structural and in vitro studies of well-dispersed monomethoxy-poly(ethylene glycol)-honokiol conjugate micelles

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Neng; Cai Lulu; Xie Dachun; Wang Guangcheng; Wu Wenshuang; Chen Lijuan [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Zhang Yongkui; Song Hang [Department of Bio-pharmaceutical Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065 (China); Yin Huabin, E-mail: lijuan17@hotmail.co [Department of Electronics and Electrical Engineering, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2010-12-15

    Honokiol, an active principle extracted from Magnolia officinalis, has great potential as a cancer treatment. However, its poor water solubility greatly hampers its delivery to the tumor sites at an effective concentration. In this study, an amphiphilic polymer-drug conjugate was successfully prepared by condensation of low molecular weight monomethoxy-poly(ethylene glycol) (MPEG)-2000 with honokiol (HK) through an ester linkage to increase the hydrophilicity of honokiol. The MPEG-honokiol (MPEG-HK) conjugate prepared formed nano-sized micelles, with a mean particle size of less than 20 nm (MPEG-HK, 360 {mu}g ml{sup -1}) in water, which could be well dispersed in water. The nanoparticles obtained were characterized by particle size distribution, morphology and zeta potential. The stability and hydrolysis profile of the polymeric pro-drug in phosphate-buffered saline (PBS) and plasma were also studied and the results showed that only 20% of the conjugated honokiol was released in 2.0 h in beagle dog plasma, while in PBS the time required to reach 20% of honokiol release was >200 h. Meanwhile, the inhibitory activity of the honokiol conjugate was found to be retained in vitro against LL/2 cell lines with an IC50 value of 10.7 {mu}g ml{sup -1}. These results suggest that the polymer-drug conjugate provides a potential new approach to hydrophobic drugs, such as honokiol, in formulation design.

  6. Drying poly(ethylene glycol)

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Lucas Kinard, Kurtis Kasper & Antonios Mikos ### Abstract This protocol describes the drying of poly(ethylene glycol) (PEG) by a simple 6 step procedure. One can implement this protocol using common lab glass and lab equipment. Water is removed from PEG by azeotropic distillation in toluene. The two components are mixed and toluene and water are distilled off by heating the solution to 170°C. This procedure can be implemented in ~2 h. ### Introduction In many ...

  7. 76 FR 70896 - Polyethylene Glycol; Tolerance Exemption

    Science.gov (United States)

    2011-11-16

    ... AGENCY 40 CFR Part 180 Polyethylene Glycol; Tolerance Exemption AGENCY: Environmental Protection Agency... amu), 17,000; also known as polyethylene glycol, when used as an inert ingredient in a pesticide...(oxyethylene, minimum number average molecular weight (in amu), 17,000; also known as polyethylene...

  8. Polyethylene Glycol Camouflaged Earthworm Hemoglobin

    Science.gov (United States)

    Moges, Selamawit; Nacharaju, Parimala; Roche, Camille; Dantsker, David; Palmer, Andre; Friedman, Joel M.

    2017-01-01

    Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals’ systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the

  9. Polyethylene glycol-electrolyte solution (PEG-ES)

    Science.gov (United States)

    Polyethylene glycol-electrolyte solution (PEG-ES) is used to empty the colon (large intestine, bowel) before a colonoscopy ( ... Polyethylene glycol-electrolyte solution (PEG-ES) comes as a powder to mix with water and take by mouth. ...

  10. Polyethylene glycol-grafted polystyrene particles

    NARCIS (Netherlands)

    Meng, Fenghua; Engbers, Gerard H.M.; Feijen, Jan

    2004-01-01

    Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS-COOH) using carbodiimide chemistry. PEG-modified particles (PS-PEG) were chara

  11. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  12. Comparison of Polyethylene Glycol-Electrolyte Solution vs Polyethylene Glycol-3350 for the Treatment of Fecal Impaction in Pediatric Patients

    OpenAIRE

    Boles, Erin E.; Gaines, Cameryn L.; Tillman, Emma M.

    2015-01-01

    OBJECTIVES: The objective of this study was to evaluate the safety and efficacy of polyethylene glycol-electrolyte solution vs polyethylene glycol-3350 for the treatment of fecal impaction in pediatric patients.

  13. Synthesis, characterization and drug loading property of Monomethoxy-Poly(ethylene glycol)-Poly(ε-caprolactone)-Poly(D,L-lactide) (MPEG-PCLA) copolymers

    Science.gov (United States)

    Chu, BingYang; Zhang, Lan; Qu, Ying; Chen, XiaoXin; Peng, JinRong; Huang, YiXing; Qian, ZhiYong

    2016-01-01

    Amphiphilic block copolymers have attracted a great deal of attention in drug delivery systems. In this work, a series of monomethoxy-poly (ethylene glycol)-poly (ε-caprolactone-co-D,L-lactide) (MPEG-PCLA) copolymers with variable composition of poly (ε-caprolactone) (PCL) and poly (D,L-lactide) (PDLLA) were prepared via ring-opening copolymerization of ε-CL and D,L-LA in the presence of MPEG and stannous octoate. The structure and molecular weight were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The crystallinity, hydrophilicity, thermal stability and hydrolytic degradation behavior were investigated in detail, respectively. The results showed that the prepared amphiphilic MPEG-PCLA copolymers have adjustable properties by altering the composition of PCLA, which make it convenient for clinical applications. Besides, the drug loading properties were also studied. Docetaxel (DTX) could be entrapped in MPEG-PCLA micelles with high loading capacity and encapsulation efficiency. And all lyophilized DTX-loaded MPEG-PCLA micelles except MPEG-PCL micelles were readily re-dissolved in normal saline at 25 °C. In addition, DTX-loaded MPEG-PCLA micelles showed a slightly enhanced antitumor activity compared with free DTX. Furthermore, DTX micelles exhibited a slower and sustained release behavior in vitro, and higher DTX concentration and longer retention time in vivo. The results suggested that the MPEG-PCLA copolymer with the adjustable ratio of PCL to PDLLA may be a promising drug delivery carrier for DTX. PMID:27677842

  14. Hydration of polyethylene glycol-grafted liposomes.

    OpenAIRE

    Tirosh, O; Barenholz, Y.; Katzhendler, J; Priev, A

    1998-01-01

    This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG...

  15. 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 perioperative setting, contained in a wide range of products seldom suspected of causing hypersensitivity reactions and thus rarely documented in surgical/anesthetic records. We suggest routine testing for PEGs after perioperative anaphylaxis because exposure to these polymers often is significant....... Comprehensive brand name documentation on the anesthetic chart of all product exposures is central to identifying the responsible allergen....

  16. Plasma proteins adsorption mechanism on polyethylene-grafted poly(ethylene glycol) surface by quartz crystal microbalance with dissipation.

    Science.gov (United States)

    Jin, Jing; Jiang, Wei; Yin, Jinghua; Ji, Xiangling; Stagnaro, Paola

    2013-06-04

    Protein adsorption has a vital role in biomaterial surface science because it is directly related to the hemocompatibility of blood-contacting materials. In this study, monomethoxy poly(ethylene glycol) (mPEG) with two different molecular weights was grafted on polyethylene as a model to elucidate the adsorption mechanisms of plasma protein through quartz crystal microbalance with dissipation (QCM-D). Combined with data from platelet adhesion, whole blood clotting time, and hemolysis rate, the blood compatibility of PE-g-mPEG film was found to have significantly improved. Two adsorption schemes were developed for real-time monitoring of protein adsorption. Results showed that the preadsorbed bovine serum albumin (BSA) on the surfaces of PE-g-mPEG films could effectively inhibit subsequent adsorption of fibrinogen (Fib). Nonspecific protein adsorption of BSA was determined by surface coverage, not by the chain length of PEG. Dense PEG brush could release more trapped water molecules to resist BSA adsorption. Moreover, the preadsorbed Fib could be gradually displaced by high-concentration BSA. However, the adsorption and displacement of Fib was determined by surface hydrophilicity.

  17. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Science.gov (United States)

    2010-07-01

    ... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under this... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amidoamine modified...

  18. Polyethylene glycol: a game-changer laxative for children.

    Science.gov (United States)

    Alper, Arik; Pashankar, Dinesh S

    2013-08-01

    Constipation is a common problem in children worldwide. It can also be a chronic problem persisting for many months to years. Successful treatment of constipation requires long-term use of laxatives. Commonly used laxatives in children include milk of magnesia, lactulose, mineral oil, and polyethylene glycol. Compared with other laxatives, polyethylene glycol (with and without electrolytes) is a relatively new laxative used during the last decade. Recent studies report excellent efficacy and safety of polyethylene glycol for the long-term treatment of constipation in children. Because of excellent patient acceptance, polyethylene glycol has become a preferred choice of laxative for many practitioners. This article reviews the recently published pediatric literature on biochemistry, efficacy, safety, patient acceptance, and pharmacoeconomics of polyethylene glycol.

  19. Separation of polyethylene glycols and maleimide-terminated polyethylene glycols by reversed-phase liquid chromatography under critical conditions.

    Science.gov (United States)

    Wei, Yanzhen; Zhuo, Renxi; Jiang, Xulin

    2016-11-01

    The separation of polyethylene glycols and maleimide-substituted polyethylene glycol derivatives based on the number of maleimide end-groups under critical liquid chromatography conditions has been investigated on a reversed-phase column. The critical solvent compositions for nonfunctional polyethylene glycols and bifunctional maleimide-substituted polyethylene glycols were determined to be identical at about 40% acetonitrile in water on a reversed-phase octadecyl carbon chain-bonded silica column using mixtures of acetonitrile and water of varying composition as the mobile phase at 25°C. The maleimide-functionalized polyethylene glycols were successfully separated according to maleimide functionality (with zero, one, two, or three maleimide end-groups, respectively) under the critical isocratic elution conditions without obvious effect of molar mass. The separation was mainly due to the hydrophobic interaction between the maleimide end-groups and the column packing. Off-line matrix-assisted laser desorption/ionization time of flight mass spectrometry was used to identify the repeating units and, especially, the end-groups of the maleimide-substituted polyethylene glycols. Liquid chromatography analysis at critical conditions could provide useful information to optimize the synthesis of functional polyethylene glycols. To our knowledge, this is the first report of the baseline separation of maleimide-functionalized polyethylene glycols based on the functionality independent of the molar mass without derivatization by isocratic elution.

  20. Immediate-type hypersensitivity to polyethylene glycols

    DEFF Research Database (Denmark)

    Wenande, E; Garvey, L H

    2016-01-01

    Polyethylene glycols (PEGs) or macrogols are polyether compounds widely used in medical and household products. Although generally considered biologically inert, cases of mild to life-threatening immediate-type PEG hypersensitivity are reported with increasing frequency. Nevertheless, awareness...... of PEG's allergenic potential remains low, due to a general lack of suspicion towards excipients and insufficient product labelling. Information on immediate-type reactions to PEG is limited to anecdotal reports, and the potential for PEG sensitization and cross-sensitization to PEGylated drugs...... to a range of unrelated products in hospital and at home. Increased awareness of PEG prevalence, PEG hypersensitivity, and improved access to PEG allergy testing, should facilitate earlier diagnosis and reduce the risk of inadvertent re-exposure. This first comprehensive review provides practical information...

  1. Polyethylene glycol-grafted polystyrene particles.

    Science.gov (United States)

    Meng, Fenghua; Engbers, Gerard H M; Feijen, Jan

    2004-07-01

    Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS-COOH) using carbodiimide chemistry. PEG-modified particles (PS-PEG) were characterized by determination of the PEG surface concentration, zeta-potential, size, and morphology. Under optimized grafting conditions, a dense "brush-like" PEG layer was formed. A PEG surface concentration of approximately 60 pmol/cm2, corresponding with an average distance between grafted PEG chains of approximately 17 A can be realized. It was shown that grafting of PEG onto PS-COOH reduced the adsorption of proteins from human plasma (85 vol %) in phosphate-buffered saline up to 90%.

  2. Role of polyethylene glycol in childhood constipation.

    Science.gov (United States)

    Phatak, Uma Padhye; Pashankar, Dinesh S

    2014-09-01

    Constipation is a common and chronic problem in children worldwide. Long-term use of laxatives is necessary for successful treatment of chronic constipation. Commonly used laxatives in children include milk of magnesia, lactulose, mineral oil, and polyethylene glycol (PEG). Recent studies report the efficacy and safety of PEG for the long-term treatment of constipation in children. Because of its excellent patient acceptance, PEG is being used widely in children for constipation. In this commentary, we review the recently published pediatric literature on the efficacy, safety, and patient acceptance of PEG. We also assess the role of PEG in childhood constipation by comparing it with other laxatives in terms of efficacy, safety, patient acceptance, and cost.

  3. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Science.gov (United States)

    2010-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  4. Effect of polyethylene glycol on electrochemically deposited trivalent chromium layers

    Institute of Scientific and Technical Information of China (English)

    Joo-Yul LEE; Man KIM; Sik-Chol KWON

    2009-01-01

    The structural characteristics of the trivalent chromium deposits and their interfacial behavior in the plating solution with and without polyethylene glycol molecules were observed by using various electrochemical methods such as cyclic voltammetry, open circuit potential transition, electrochemical impedance spectroscopy, scanning electron microscopy and X-ray photoelectron spectrometry. It is shown that the polyethylene glycol molecules make the reductive current density lower in the trivalent chromium plating system and promote a hydrogen evolution reaction through their adsorption on the electrode surface. And the trivalent chromium layer formed from the polyethylene glycol-containing solution has somewhat higher density of cracks on its surface and results in a lower film resistance, lower polarization resistance, and higher capacitance in a corrosive atmosphere. It is also revealed that the formation of chromium carbide layer is facilitated in the presence of polyethylene glycol, which means easier electrochemical codeposition of chromium and carbon, not single chromium deposition.

  5. Effect of drought stress induced by polyethylene glycol (PEG) on ...

    African Journals Online (AJOL)

    Effect of drought stress induced by polyethylene glycol (PEG) on germination indices in corn ( Zea mays L.) hybrids. ... African Journal of Biotechnology ... and success in this stage is dependent on moisture content of soil at time of planting.

  6. Crystallization studies of polyethylene -poly(ethylene glycol) graft copolymers

    Science.gov (United States)

    Mark, P. R.; Hovey, G. E.; Murthy, N. S.; Breitenkamp, K.; Kade, M.; Emerick, T.

    2006-03-01

    Structure and crystallization behavior of three copolymers obtained by grafting poly (ethylene glycol) (PEG) chains to polyethylene (PE) main chain was investigated by variable temperature x-ray diffraction and thermal analysis. The results show that PEG side chains and PE main chains crystallize into separate domains. This is especially true when grafted chains are long (50 and 100 repeat units), in which the PEG domains are same as in PEG homopolymer both in structure and in melting behavior. In the copolymer with shorter chains (25 repeat units), the PEG crystals are not distinct and melting is broad. The PEG domains can be dissolved in water or ethanol without altering the mechanical integrity of the film. PE crystallites in both samples are similar to that in PE homopolymer. For instance, the thermal expansion of the basal cell plane (a- and b-axes) of the PE domains agrees well with that of PE homopolymer over the entire temperature range from ambient to melt. However, the chain-axis dimension PE-lattice in the copolymer is shorter by ˜ 0.05 å and the basal dimensions are larger by ˜ 0.05 å. The changes in these dimensions due to the changes in the length of the grafted PEG chains were investigated.

  7. Steric Stabilization of “Charge-Free” Cellulose Nanowhiskers by Grafting of Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Jun Araki

    2014-12-01

    Full Text Available A sterically stabilized aqueous suspension of “charge-free” cellulose nanowhiskers was prepared by hydrochloric acid hydrolysis of cotton powders and subsequent surface grafting of monomethoxy poly(ethylene glycol (mPEG. The preparation scheme included carboxylation of the terminal hydroxyl groups in mPEG via oxidation with silica gel particles carrying 2,2,6,6-tetramethyl-1-pyperidinyloxyl (TEMPO moieties and subsequent esterification between terminal carboxyls in mPEG and surface hydroxyl groups of cellulose nanowhiskers, mediated by 1,1'-carbonyldiimidazole (CDI in dimethyl sulfoxide or dimethylacetamide. Some of the prepared PEG-grafted samples showed remarkable flow birefringence and enhanced stability after 24 h, even in 0.1 M NaCl, suggesting successful steric stabilization by efficient mPEG grafting. Actual PEG grafting via ester linkages was confirmed by attenuated total reflectance-Fourier transform infrared spectrometry. In a typical example, the amount of grafted mPEG was estimated as ca. 0.3 g/g cellulose by two measurements, i.e., weight increase after grafting and weight loss after alkali cleavage of ester linkages. Transmission electron microscopy indicated unchanged nanowhisker morphology after mPEG grafting.

  8. Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Brullot, W., E-mail: ward.brullot@fys.kuleuven.be [Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Heverlee, Leuven (Belgium); Reddy, N.K. [Department of Chemical Engineering, Katholieke Universiteit Leuven, Willem de Croylaan 46, 3001 Heverlee, Leuven (Belgium); Wouters, J.; Valev, V.K.; Goderis, B. [Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Heverlee, Leuven (Belgium); Vermant, J. [Department of Chemical Engineering, Katholieke Universiteit Leuven, Willem de Croylaan 46, 3001 Heverlee, Leuven (Belgium); Verbiest, T. [Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Heverlee, Leuven (Belgium)

    2012-06-15

    Versatile ferrofluids based on polyethylene glycol coated iron oxide nanoparticles were obtained by a facile protocol and thoroughly characterized. Superparamagnetic iron oxide nanoparticles synthesized using a modified forced hydrolysis method were functionalized with polyethylene glycol silane (PEG silane), precipitated and dried. These functionalized particles are dispersable in a range of solvents and concentrations depending on the desired properties. Examples of tunable properties are magnetic behavior, optical and magneto-optical response, thermal features and rheological behavior. As such, PEG silane functionalized particles represent a platform for the development of new materials that have broad applicability in e.g. biomedical, industrial or photonic environments. Magnetic, optical, magneto-optical, thermal and rheological properties of several ferrofluids based on PEG coated particles with different concentrations of particles dispersed in low molecular mass polyethylene glycol were investigated, establishing the applicability of such materials. - Highlights: Black-Right-Pointing-Pointer Ferrofluids based on polyethylene glycol coated iron oxide nanoparticles. Black-Right-Pointing-Pointer Magnetic, optical, magneto-optical, thermal and rheological characterization of ferrofluids. Black-Right-Pointing-Pointer Tunable properties of versatile polyethylene glycol stabilized ferrofluids.

  9. Pulmonary surfactant adsorption is increased by hyaluronan or polyethylene glycol.

    Science.gov (United States)

    Taeusch, H William; Dybbro, Eric; Lu, Karen W

    2008-04-01

    In acute lung injuries, inactivating agents may interfere with transfer (adsorption) of pulmonary surfactants to the interface between air and the aqueous layer that coats the interior of alveoli. Some ionic and nonionic polymers reduce surfactant inactivation in vitro and in vivo. In this study, we tested directly whether an ionic polymer, hyaluronan, or a nonionic polymer, polyethylene glycol, enhanced adsorption of a surfactant used clinically. We used three different methods of measuring adsorption in vitro: a modified pulsating bubble surfactometer; a King/Clements device; and a spreading trough. In addition we measured the effects of both polymers on surfactant turbidity, using this assay as a nonspecific index of aggregation. We found that both hyaluronan and polyethylene glycol significantly increased the rate and degree of surfactant material adsorbed to the surface in all three assays. Hyaluronan was effective in lower concentrations (20-fold) than polyethylene glycol and, unlike polyethylene glycol, hyaluronan did not increase apparent aggregation of surfactant. Surfactant adsorption in the presence of serum was also enhanced by both polymers regardless of whether hyaluronan or polyethylene glycol was included with serum in the subphase or added to the surfactant applied to the surface. Therefore, endogenous polymers in the alveolar subphase, or exogenous polymers added to surfactant used as therapy, may both be important for reducing inactivation of surfactant that occurs with various lung injuries.

  10. Injectable silk-polyethylene glycol hydrogels.

    Science.gov (United States)

    Wang, Xiaoqin; Partlow, Benjamin; Liu, Jian; Zheng, Zhaozhu; Su, Bo; Wang, Yansong; Kaplan, David L

    2015-01-01

    Silk hydrogels for tissue repair are usually pre-formed via chemical or physical treatments from silk solutions. For many medical applications, it is desirable to utilize injectable silk hydrogels at high concentrations (>8%) to avoid surgical implantation and to achieve slow in vivo degradation of the gel. In the present study, injectable silk solutions that formed hydrogels in situ were generated by mixing silk with low-molecular-weight polyethylene glycol (PEG), especially PEG300 and 400 (molecular weight 300 and 400g mol(-1)). Gelation time was dependent on the concentration and molecular weight of PEG. When the concentration of PEG in the gel reached 40-45%, gelation time was less than 30min, as revealed by measurements of optical density and rheological studies, with kinetics of PEG400 faster than PEG300. Gelation was accompanied by structural changes in silk, leading to the conversion from random coil in solution to crystalline β-sheets in the gels, based on circular dichroism, attenuated total reflection Fourier transform infrared spectroscopy and X-ray diffraction. The modulus (127.5kPa) and yield strength (11.5kPa) determined were comparable to those of sonication-induced hydrogels at the same concentrations of silk. The time-dependent injectability of 15% PEG-silk hydrogel through 27G needles showed a gradual increase of compression forces from ∼10 to 50N within 60min. The growth of human mesenchymal stem cells on the PEG-silk hydrogels was hindered, likely due to the presence of PEG, which grew after a 5 day delay, presumably while the PEG solubilized away from the gel. When 5% PEG-silk hydrogel was subcutaneously injected in rats, significant degradation and tissue in-growth took place after 20 days, as revealed by ultrasound imaging and histological analysis. No significant inflammation around the gel was observed. The features of injectability, slow degradation and low initial cell attachment suggests that these PEG-silk hydrogels are of interest

  11. A Coarse-Grained Model for Polyethylene Oxide and Polyethylene Glycol : Conformation and Hydrodynamics

    NARCIS (Netherlands)

    Lee, Hwankyu; de Vries, Alex H.; Marrink, Siewert-Jan; Pastor, Richard W.

    2009-01-01

    A coarse-grained (CG) model for polyethylene oxide (PEO) and polyethylene glycol (PEG) developed within the framework of the MARTINI CG force field (FF) using the distributions of bonds, angles, and dihedrals from the CHARMM all-atom FF is presented. Densities of neat low molecular weight PEO agree

  12. A Coarse-Grained Model for Polyethylene Oxide and Polyethylene Glycol : Conformation and Hydrodynamics

    NARCIS (Netherlands)

    Lee, Hwankyu; de Vries, Alex H.; Marrink, Siewert-Jan; Pastor, Richard W.

    2009-01-01

    A coarse-grained (CG) model for polyethylene oxide (PEO) and polyethylene glycol (PEG) developed within the framework of the MARTINI CG force field (FF) using the distributions of bonds, angles, and dihedrals from the CHARMM all-atom FF is presented. Densities of neat low molecular weight PEO agree

  13. Preparation of amino-terminated poly(ethylene glycol)by periodate oxidation%高碘酸氧化法制备端氨基聚乙二醇的研究

    Institute of Scientific and Technical Information of China (English)

    陈阳建; 许丽丽; 张新波; 彭富君; 宋潇达

    2015-01-01

    Monomethoxy poly( ethylene glycol)tosylate( mPEG5000-OTs)was synthesized by sulfonic esterification from monomethoxy poly(ethylene glycol)5000(mPEG5000)and p-toluenesulfonyl chloride (p-TsCl),and then reacted with ethanolamine as nucleophile to produce a new poly(ethylene glycol)in-termediate with the β-amino alcohol structure at the end. Amino-terminated poly( ethylene glycol ) (mPEG5000-NH2 )with the relative molecular mass of 5 000 was 75. 1% . The structures of products were characterized and identified by IR and 1 H NMR.%单甲氧基聚乙二醇5000(mPEG5000)和对甲苯磺酰氯(p-TsCl)磺酸酯化,得到单甲氧基聚乙二醇对甲苯磺酸酯(mPEG5000-OTs),与乙醇胺亲核取代反应,获得末端具有β-氨基醇结构的聚乙二醇中间体,用高碘酸盐氧化,得相对分子质量5000的端氨基聚乙二醇(mPEG5000-NH2),总收率75.1%,产物结构通过 IR 和1 H NMR 进行表征。

  14. Radioimmunoprecipitation polyethylene glycol assay for circulating Entamoeba histolytica antigens

    Energy Technology Data Exchange (ETDEWEB)

    Pillai, S.; Mohimen, A.; Mehra, S. (Calcutta Medical Research Inst., Calcutta (India). Kothari Centre of Gastroenterology)

    1982-12-17

    An assay capable of detecting circulating Entamoeba histolytica antigens in amoebiasis is described. This assay utilised a radiolabelled affinity purified rabbit anti-E. histolytica antibody that had been depleted of antibodies that cross-react with human serum proteins, and a polyethylene glycol precipitation step.

  15. Simulation of polyethylene glycol and calcium-mediated membrane fusion

    NARCIS (Netherlands)

    Pannuzzo, Martina; De Jong, Djurre H.; Raudino, Antonio; Marrink, Siewert J.

    2014-01-01

    We report on the mechanism of membrane fusion mediated by polyethylene glycol (PEG) and Ca2+ by means of a coarse-grained molecular dynamics simulation approach. Our data provide a detailed view on the role of cations and polymer in modulating the interaction between negatively charged apposed membr

  16. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  17. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Science.gov (United States)

    2011-11-09

    ... AGENCY 40 CFR Part 180 Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether... residues of methacrylic acid-methyl methacrylate- polyethylene glycol monomethyl ether methacrylate graft... permissible level for residues of methacrylic acid-methyl methacrylate-polyethylene glycol monomethyl...

  18. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  19. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  20. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  1. Stabilization of Polyethylene Glycol in Archaeological Wood

    DEFF Research Database (Denmark)

    Mortensen, Martin Nordvig

    Projektet har fokuseret på polythylen glycol (PEG) stabilitet og nedbrydning i træ fra konserverede skibsvrag som Vasa (Stockholm) og Skuldelev skibene. En række avancerede analyseteknikker er anvendt til at undersøge indtrængningsdybden for forskellige molekylstørrelser PEG i ikke-nedbrudt træ fra...

  2. Synthesis of Degradable Poly[(Ethylene Glycol)-co-(Glycolic Acid)] via the Post-Polymerization Oxyfunctionalization of Poly(Ethylene Glycol).

    Science.gov (United States)

    Liu, Di; Bielawski, Christopher W

    2016-10-01

    To enhance the limited degradability of poly(ethylene glycol) (PEG), a straightforward method of synthesizing poly[(ethylene glycol)-co-(glycolic acid)] (P(EG-co-GA)) via a ruthenium-catalyzed, post-polymerization oxyfunctionalization of various PEGs is developed. Using this method, a set of copolymers with GA compositions of up to 8 mol% are prepared with minimal reduction in molecular weight (<10%) when compared to their commercially available starting materials. The P(EG-co-GA) copolymers are shown to undergo hydrolysis under mild conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Multimeric, Multifunctional Derivatives of Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Gian Maria Bonora

    2011-07-01

    Full Text Available This article reviews the use of multifunctional polymers founded on high-molecular weight poly(ethylene glycol (PEG. The design of new PEG derivatives assembled in a dendrimer-like multimeric fashion or bearing different functionalities on the same molecule is described. Their use as new drug delivery systems based on the conjugation of multiple copies or diversely active drugs on the same biocompatible support is illustrated.

  4. POLYMERIZATION OF ETHYLENE METHYL PHOSPHATE IN THE PRESENCE OF SODIUM POLY(ETHYLENE GLYCOL)ATE

    Institute of Scientific and Technical Information of China (English)

    Jie Wen; Ren-xi Zhuo; Lu Wang

    1999-01-01

    Poly(ethylene methyl phosphate)-poly(ethylene glycol)-poly(ethylene methyl phosphate) triblock copolymers carrying hydroxyl group at both chain ends were synthesized with sodium poly(ethylene glycol)ate as initiator. The effects of the factors such as solvent, amount of the initiator and reaction time were investigated. The copolymers were characterized by IR, 1H-NMR, 1H{31p}-NMR, 13C-NMR, 31P{1H}-NMR, and DSC. High molecular weight of the copolymer and high yield of the polymerization were achieved within 3 min at 25℃. The polymerization process was studied by 31P{1H}-NMR and transesterification was found during longer polymerization time.

  5. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729 Boric...

  6. Self-assembly of silanated poly(ethylene glycol) on silicon and glass surfaces for improved haemocompatibility

    Science.gov (United States)

    Guo, Zhang; Meng, Sheng; Zhong, Wei; Du, Qiangguo; Chou, Laisheng L.

    2009-05-01

    Surface immobilization of poly(ethylene glycol) (PEG) is an effective method to produce a material surface with protein repulsive property. This property could be made permanent by using covalent grafting of the PEG molecules onto material surfaces. In this study, self-assembled monolayers (SAMs) of PEG on silicon-containing materials (silicon chip and glassplate) were obtained through a one-step coating procedure of one kind of silanated PEG molecules made through the reaction between monomethoxy PEG and 3-isocyanatopropyltriethoxysilane. Atomic force microscopy (AFM) and water static contact angle measurement were employed to investigate the surface topography and wettability of the PEGylated material surfaces. The changes in the topography and the water contact angle of the surfaces with time of incubation in PBS solution were also measured. The results revealed that stable and uniform self-assembled monolayers of PEG could be formed on silicon or glass surfaces by simply soaking the substrates in the solution of silanated PEGs. The covalent coupling of PEGs to the substrates was also confirmed. In order to evaluate the stability of the SAMs, blood compatibility of the modified glassplate surface was evaluated by measuring full blood activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT), as well as by scanning electron microscopy (SEM) analysis of the appearance of adherence and denaturation of blood platelets onto the glassplate. The silanated PEGs were shown to have good effect on the protein-repulsion as well as haemocompatibility of the substrates.

  7. Polyethylene glycol plus ascorbic acid for bowel preparation in chronic kidney disease.

    Science.gov (United States)

    Lee, Jae Min; Keum, Bora; Yoo, In Kyung; Kim, Seung Han; Choi, Hyuk Soon; Kim, Eun Sun; Seo, Yeon Seok; Jeen, Yoon Tae; Chun, Hoon Jai; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck; Kim, Myung Gyu; Jo, Sang Kyung

    2016-09-01

    The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function.

  8. The effect of glycerol, propylene glycol and polyethylene glycol 400 on the partition coefficient of benzophenone-3 (oxybenzone).

    Science.gov (United States)

    Mbah, C J

    2007-01-01

    Sunscreen products are widely used to protect the skin from sun-related deleterious effects. The objective of the study was to investigate the potential effect of glycerol, propylene glycol and polyethylene glycol 400 on dermal absorption of oxybenzone by studying their effects on its partition coefficient. The partition coefficient was evaluated in a chloroform-water system at room temperature. It was found that glycerol and propylene glycol decreased the partition coefficient of oxybenzone, while an increase in partition coefficient was observed with polyethylene glycol 400. The findings suggest that polyethylene glycol 400 in contrast to glycerol and propylene glycol has the potential of increasing the vehicle-skin partition coefficient of oxybenzone when cosmetic products containing such an UV absorber are topically applied to the skin.

  9. Capture and utilization of carbon dioxide with polyethylene glycol

    CERN Document Server

    Yang, Zhen-Zhen; He, Liang-Nian

    2012-01-01

    In this volume, Professor He and his coworkers summarize polyethylene glycol (PEG)-promoted CO2 chemistry on the basis of understanding about phase behavior of PEG/CO2 system and reaction mechanism at molecular level. As PEG could be utilized as a green replacement for organic solvents, phase-transfer catalyst, surfactant, support in various reaction systems, significantly promoting catalytic activity and recovering expensive metal catalysts, particularly regarded as a CO2-philic material, the authors focus on special applications of PEG in CO2 capture and utilization, including PEG-functional

  10. Effect of polyethylene glycol on characteristics of chitosan membranes

    Directory of Open Access Journals (Sweden)

    Puthai, W.

    2005-07-01

    Full Text Available This work reports the influence of polyethylene glycol (PEG on characteristics of chitosan membranes. Parameters used for membrane characterization were hydraulic permeability (Lp, molecular weight cut off (MWCO, and membrane impedance (Z. The results obtained from LP and Z imply that larger a amount of PEG addition enhances membrane porosity and enlarges the pore size. The prepared membranes were ultrafiltration type, with MWCO slightly greater than 35 kDa. Membranes without PEG additioncould be nanofiltration type with Lp value of 0.4x10-11 m3 N-1 s-1, 10-20 times smaller than the other.

  11. Micropatterning of poly(ethylene glycol) diacrylate hydrogels.

    Science.gov (United States)

    Ali, Saniya; Cuchiara, Maude L; West, Jennifer L

    2014-01-01

    This protocol describes the techniques to synthesize and fabricate micropatterned poly(ethylene glycol) diacrylate-based hydrogels that can be used as substrates in cellular studies and tissue engineering scaffolds. These materials provide an essentially bioinert background material due to the very low protein adsorption characteristics of poly(ethylene glycol), but the materials can be modified with covalently grafted peptides, proteins, or other biomolecules of interest to impart specific biofunctionality to the material. Further, it is possible to use micropatterning technologies to control the localization of such covalent grafting of biomolecules to the hydrogel materials, thus spatially controlling the cell-material interactions. This protocol presents a relatively simple approach for mask-based photolithographic patterning, generally best suited for patterning the surface of hydrogel materials for 2D cell studies. A more sophisticated technique, two-photon laser scanning lithography, is also presented. This technique allows free-form, 3D micropatterning in hydrogels. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Identification of polypropylene glycols and polyethylene glycol carboxylates in flowback and produced water from hydraulic fracturing.

    Science.gov (United States)

    Thurman, E Michael; Ferrer, Imma; Rosenblum, James; Linden, Karl; Ryan, Joseph N

    2017-02-05

    The purpose of the study was to separate and identify the unknown surfactants present in flowback and produced water from oil and gas wells in the Denver-Julesburg Basin (Niobrara Formation) in Weld County, Colorado, USA. Weld County has been drilled extensively during the last five years for oil and gas between 7000-8000 feet below land-surface. Polypropylene glycols (PPGs) and polyethylene glycols carboxylates (PEG-Cs) were found for the first time in these flowback and produced water samples. These ethoxylated surfactants may be used as friction reducers, clay stabilizers, and surfactants. Ultrahigh-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UHPLC/QTOF-MS) was used to separate and identify the different classes of PPGs, PEG-Cs, and their isomers. The Kendrick mass scale was applied along with mass spectrometry/mass spectrometry (MS-MS) with accurate mass for rapid and unequivocal identification. The PPGs and their isomers occur at the ppm concentration range and may be useful as "fingerprints" of hydraulic-fracturing. Comparing these detections to the compounds used in the fracturing process from FracFocus 3.0 (https://fracfocus.org), it appears that both PPGs and polyethylene glycols (PEGs) are commonly named as additives, but the PEG-Cs have not been reported. The PEG-Cs may be trace impurities or degradation products of PEGs.

  13. Polyethylene glycol-hirudin conjugates, process for preparing them and their use for the treatment of thromboses

    NARCIS (Netherlands)

    Bischoff, Rainer; Transgene, S.A.

    1994-01-01

    The present invention relates to a process for preparing a polyethylene glycol (or derivatives)-hirudin conjugate. It also relates to the polyethylene glycol (or derivatives)-hirudin conjugate obtained and its use as medicinal product for the..

  14. Experimental study on correlation between sound velocity and solute molecular weight in polyethylene glycol solution

    Institute of Scientific and Technical Information of China (English)

    YIN XiangYu; SONG Hao; ZHOU HuiJun

    2009-01-01

    In this study, ultrasound grating was used to measure the sound velocity in solutions of ethylene glycol and polyethylene glycol with molecular weights of 200, 600, 2000, and 10000. We found Parthasarathy empirical rule, that is, sound velocity is higher in the solution of larger molecules, is invalid in the case of polyethylene glycol solution. We tried to provide a tentative explanation using the Flory-Krigbaum's chained block cloud model.

  15. Experimental study on correlation between sound velocity and solute molecular weight in polyethylene glycol solution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this study,ultrasound grating was used to measure the sound velocity in solutions of ethylene glycol and polyethylene glycol with molecular weights of 200,600,2000,and 10000.We found Parthasarathy empirical rule,that is,sound velocity is higher in the solution of larger molecules,is invalid in the case of polyethylene glycol solution. We tried to provide a tentative explanation using the Flory-Krigbaum’s chained block cloud model.

  16. Poly(ethylene glycol)s as Ligands in Calcium-Catalyzed Cyclic Carbonate Synthesis.

    Science.gov (United States)

    Steinbauer, Johannes; Werner, Thomas

    2017-08-10

    Herein the use of CaI2 in combination with poly(ethylene glycol) dimethyl ether (PEG DME 500) as an efficient catalyst system for the addition of CO2 to epoxides is reported. This protocol is based on a nontoxic and abundant metal in conjunction with a polymeric ligand. Fifteen terminal epoxides were converted at room temperature to give the desired products in yields up to 99 %. Notably, this system was also effective for the synthesis of twelve challenging internal carbonates in yields up to 98 %. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Hansen solubility parameters for polyethylene glycols by inverse gas chromatography.

    Science.gov (United States)

    Adamska, Katarzyna; Voelkel, Adam

    2006-11-03

    Inverse gas chromatography (IGC) has been applied to determine solubility parameter and its components for nonionic surfactants--polyethylene glycols (PEG) of different molecular weight. Flory-Huggins interaction parameter (chi) and solubility parameter (delta(2)) were calculated according to DiPaola-Baranyi and Guillet method from experimentally collected retention data for the series of carefully selected test solutes. The Hansen's three-dimensional solubility parameters concept was applied to determine components (delta(d), delta(p), delta(h)) of corrected solubility parameter (delta(T)). The molecular weight and temperature of measurement influence the solubility parameter data, estimated from the slope, intercept and total solubility parameter. The solubility parameters calculated from the intercept are lower than those calculated from the slope. Temperature and structural dependences of the entopic factor (chi(S)) are presented and discussed.

  18. Synthesis of Propargyl-Terminated Heterobifunctional Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Wen Zhong

    2010-10-01

    Full Text Available Novel propargyl-ended heterobifunctional poly(ethylene glycol (PEG derivatives with hydroxyl, carboxyl, mercapto or hydrazide end groups were synthesized with simplicity yet high efficiency. PEG (Mw = 3500 Da with an α-hydroxyl group and an ω-carboxyl was used as the starting polymer. The carboxyl group of the bifunctional PEG was modified into a propargyl, then carboxyl, mercapto or hydrazide groups were introduced to the other end of the bifunctional PEG by modifying the bifunctional PEG’s hydroxyl group with succinic anhydride, cysteamide or tert-butyl carbazate, respectively. This method can be useful to the development of PEG-based bioconjugates for a variety of biomedical applications.

  19. Isothermal Crystallization Kinetics of Microencapsulated Polyethylene Glycol Particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microencapsulated polyethylene glycol (PEG)with different molecular weight by a fluidized coating method has been prepared and the crystallization behaviors of PEG particles in three-dimensional confined volume were investigated by using differential scanning calorimetry(DSC) measurement.The results showed that the width of the crystallization peak of PEG increases and its height gradually diminishes in case that the PEG particles are microencapsulated. Compared with the non-microencapsulated PEG particles, the proportion of the first crystallization peak of microencapsulated PEG particle increases, and that of the second one decreases. The reason for the difference maybe is that the crystallization process of microencapsulated PEG particles is uniform and the crystallization ends when the spherulites touch the wall,thus the opportunity of producing the second crystallization peak was relatively reduced.

  20. Fabrication of poly(ethylene glycol) hydrogel microstructures using photolithography

    Science.gov (United States)

    Revzin, A.; Russell, R. J.; Yadavalli, V. K.; Koh, W. G.; Deister, C.; Hile, D. D.; Mellott, M. B.; Pishko, M. V.

    2001-01-01

    The fabrication of hydrogel microstructures based upon poly(ethylene glycol) diacrylates, dimethacrylates, and tetraacrylates patterned photolithographically on silicon or glass substrates is described. A silicon/silicon dioxide surface was treated with 3-(trichlorosilyl)propyl methacrylate to form a self-assembled monolayer (SAM) with pendant acrylate groups. The SAM presence on the surface was verified using ellipsometry and time-of-flight secondary ion mass spectrometry. A solution containing an acrylated or methacrylated poly(ethylene glycol) derivative and a photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was spin-coated onto the treated substrate, exposed to 365 nm ultraviolet light through a photomask, and developed with either toluene, water, or supercritical CO2. As a result of this process, three-dimensional, cross-linked PEG hydrogel microstructures were immobilized on the surface. Diameters of cylindrical array members were varied from 600 to 7 micrometers by the use of different photomasks, while height varied from 3 to 12 micrometers, depending on the molecular weight of the PEG macromer. In the case of 7 micrometers diameter elements, as many as 400 elements were reproducibly generated in a 1 mm2 square pattern. The resultant hydrogel patterns were hydrated for as long as 3 weeks without delamination from the substrate. In addition, micropatterning of different molecular weights of PEG was demonstrated. Arrays of hydrogel disks containing an immobilized protein conjugated to a pH sensitive fluorophore were also prepared. The pH sensitivity of the gel-immobilized dye was similar to that in an aqueous buffer, and no leaching of the dye-labeled protein from the hydrogel microstructure was observed over a 1 week period. Changes in fluorescence were also observed for immobilized fluorophore labeled acetylcholine esterase upon the addition of acetyl acholine.

  1. Influence of polyethylene glycol-300 addition on nanostructured lead sulfide thin films properties

    Science.gov (United States)

    Kaci, S.; Keffous, A.; Trari, M.; Menari, H.; Manseri, A.; Mahmoudi, B.; Guerbous, L.

    2010-09-01

    The concentration of polyethylene glycol-300 was found to play a crucial role in the formation of nanoparticles in PbS-chemical bath deposition process. We report here an endeavor to set up a relation between the variation of lead sulfide (PbS) nanocrystalline thin film properties, grown by (CBD) process at room temperature on corning glass and Si(100) substrates, with amount fluctuations of polyethylene glycol-300 in the solution. The transmittance of the films, for a fixed reaction time, increased up to ˜ 80% with the increase of % polyethylene glycol-300 in the solution, indicating the formation of very thin films due to the decrease of reaction rate with the increase of the concentration of polyethylene glycol-300. The optical band gaps were found to strongly rely on the composition of the bath deposition and increase with the increase of the polyethylene glycol-300 amount in the solution. Particle sizes between 2.8 and 8.7 nm were obtained by varying the % of polyethylene glycol-300 from 0.2 to 1.5. The concentration of polyethylene glycol-300 not only affects the reaction rate but also the morphology of the obtained films. PbS nanoparticles were found to be oriented preferentially along the plane. The absorption shifts towards short wavelength indicating a blue-shifting as a consequence of quantum confinement.

  2. Zinc phthalocyanine labelled polyethylene glycol: preparation, characterization, interaction with bovine serum albumin and near infrared fluorescence imaging in vivo.

    Science.gov (United States)

    Lv, Feng; Cao, Bo; Cui, Yanli; Liu, Tianjun

    2012-05-25

    Zinc phthalocyanine labelled polyethylene glycol was prepared to track and monitor the in vivo fate of polyethylene glycol. The chemical structures were characterized by nuclear magnetic resonance and infrared spectroscopy. Their light stability and fluorescence quantum yield were evaluated by UV-Visible and fluorescence spectroscopy methods. The interaction of zinc phthalocyanine labelled polyethylene glycol with bovine serum albumin was evaluated by fluorescence titration and isothermal titration calorimetry methods. Optical imaging in vivo, organ aggregation as well as distribution of fluorescence experiments for tracking polyethylene glycol were performed with zinc phthalocyanine labelled polyethylene glycol as fluorescent agent. Results show that zinc phthalocyanine labelled polyethylene glycol has good optical stability and high emission ability in the near infrared region. Imaging results demonstrate that zinc phthalocyanine labelled polyethylene glycol can track and monitor the in vivo process by near infrared fluorescence imaging, which implies its potential in biomaterials evaluation in vivo by a real-time noninvasive method.

  3. Hexanoic acid and polyethylene glycol double grafted amphiphilic chitosan for enhanced gene delivery: influence of hydrophobic and hydrophilic substitution degree.

    Science.gov (United States)

    Layek, Buddhadev; Haldar, Manas K; Sharma, Gitanjali; Lipp, Lindsey; Mallik, Sanku; Singh, Jagdish

    2014-03-03

    Gene therapy holds immense potential as a future therapeutic strategy for the treatment of numerous genetic diseases which are incurable to date. Nevertheless, safe and efficient gene delivery remains the most challenging aspects of gene therapy. To overcome this difficulty a series of hexanoic acid (HA) and monomethoxy poly(ethylene glycol) (mPEG) double grafted chitosan-based (HPC) nanomicelles were developed as nonviral gene carrier. HPC polymers with various HA and mPEG substitution degrees were synthesized, and their chemical structures were confirmed by (1)H NMR spectroscopy. HPC nanomicelles exhibited excellent blood compatibility and cell viability, as demonstrated by in vitro hemolysis and MTT assay, respectively. The cationic HPC nanomicelles retained the plasmid DNA (pDNA) binding capacity of chitosan and formed stable HPC/pDNA polyplexes with diameters below 200 nm. Both hydrophobic and hydrophilic substitution resulted in suppressed nonspecific protein adsorption on HPC/pDNA polyplexes and increased pDNA dissociation. However, resistance against DNase I degradation was enhanced by HA conjugation while being inhibited by mPEG substitution. Amphiphilic modification resulted in 3-4.5-fold higher cellular uptake in human embryonic kidney 293 cells (HEK 293) mainly through clathrin-mediated pathway. The optimal HPC/pDNA polyplexes displayed 50-fold and 1.2-fold higher gene transfection compared to unmodified chitosan and Fugene, respectively, in HEK 293 cells. Moreover, both the cellular uptake and in vitro transfection study suggested a clear dependence of gene expression on the extent of HA and mPEG substitution. These findings demonstrate that amphiphilic HPC nanomicelles with the proper combination of HA and mPEG substitution could be used as a promising gene carrier for efficient gene therapy.

  4. Surface modification of polypropylene membrane by polyethylene glycol graft polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Abednejad, Atiye Sadat, E-mail: atiyeabednejad@gmail.com [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Amoabediny, Ghasem [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of); Research Center for New Technologies in Life Science Engineering, University of Tehran, P.O. Box 63894-14179, Tehran (Iran, Islamic Republic of); Ghaee, Azadeh [Department of Biomedical Engineering, Faculty of New Sciences and Technologies, University of Tehran, P.O. Box 14395-1561, Tehran (Iran, Islamic Republic of)

    2014-09-01

    Polypropylene hollow fiber microporous membranes have been used in a wide range of applications, including blood oxygenator. The hydrophobic feature of the polypropylene surface causes membrane fouling. To minimize fouling, a modification consisting of three steps: surface activation in H{sub 2} and O{sub 2} plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37 °C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant. - Highlights: • H{sub 2} and O{sub 2} plasma graft polymerization of PEG on polypropylene membrane was carried out. • Changes in surface properties were investigated by FTIR, XPS, SEM, and AFM. • Surface wettability enhanced as a result of poly ethylene glycol grafting. • PEG grafting degree increase causes reduction of fouling and adhesion.

  5. Preparation of Fe3O4Spherical Nanoporous Particles Facilitated by Polyethylene Glycol 4000

    Directory of Open Access Journals (Sweden)

    Wang Li-Li

    2009-01-01

    Full Text Available Abstract Much interest has been attracted to the magnetic materials with porous structure because of their unique properties and potential applications. In this report, Fe3O4nanoporous particles assembled from small Fe3O4nanoparticles have been prepared by thermal decomposition of iron acetylacetonate in the presence of polyethylene glycol 4000. The size of the spherical nanoporous particles is 100–200 nm. Surface area measurement shows that these Fe3O4nanoporous particles have a high surface area of 87.5 m2/g. Magnetization measurement and Mössbauer spectrum indicate that these particles are nearly superparamagnetic at room temperature. It is found that the morphology of the products is greatly influenced by polyethylene glycol concentration and the polymerization degree of polyethylene glycol. Polyethylene glycol molecules are believed to facilitate the formation of the spherical assembly.

  6. Miscibility studies of Polyethylene Glycol with Polystyrene in Toluene by Various Physical and Advanced Techniques

    Science.gov (United States)

    Padmanaban, R.; Venkatramanan, K.

    2016-10-01

    Polyethylene glycol (PEG) is a chemical that has an extensive variety of applications in the world of medicine. It is used as a base to manufacture certain medicines, assist in drug delivery, and is also used as an agent in some medical procedures. It is an osmotic laxative. Polyethylene glycol works by retaining water in the stool, resulting in softer stools and more frequent bowel movements. Polyethylene glycol does not affect glucose and electrolytes in the body. PEG refers to a hydrocarbon molecule that can have a variable size, and different sizes can have different physical properties, giving this compound a great deal of flexibility in its application. In the present study, Polyethylene Glycol (PEG) (Molar mass: 1500) is blended with Polystyrene (PS) (Molar mass: 35000) in Toluene. The miscibility nature of the poly blend is analyzed by Ultrasonic velocity, viscosity, density and refractive index techniques at 303K. The compatibility nature of the blend is confirmed by Differential Scanning Calorimetry (DSC) studies.

  7. Highly conductive solid polymer electrolyte membranes based on polyethylene glycol-bis-carbamate dimethacrylate networks

    Science.gov (United States)

    Fu, Guopeng; Dempsey, Janel; Izaki, Kosuke; Adachi, Kaoru; Tsukahara, Yasuhisa; Kyu, Thein

    2017-08-01

    In an effort to fabricate highly conductive, stable solid-state polymer electrolyte membranes (PEM), polyethylene glycol bis-carbamate (PEGBC) was synthesized via condensation reaction between polyethylene glycol diamine and ethylene carbonate. Subsequently, dimethacrylate groups were chemically attached to both ends of PEGBC to afford polyethylene glycol-bis-carbamate dimethacrylate (PEGBCDMA) precursor having crosslinking capability. The melt-mixed ternary mixtures consisting of PEGBCDMA, succinonitrile plasticizer, and lithium trifluorosulphonyl imide salt were completely miscible in a wide compositional range. Upon photo-crosslinking, the neat PEGBCDMA network was completely amorphous exhibiting higher tensile strength, modulus, and extensibility relative to polyethylene glycol diacrylate (PEGDA) counterpart. Likewise, the succinonitrile-plasticized PEM network containing PEGBCDMA remained completely amorphous and transparent upon photo-crosslinking, showing superionic conductivity, improved thermal stability, and superior tensile properties with improved capacity retention during charge/discharge cycling as compared to the PEGDA-based PEM.

  8. Polyethylene Glycol Drilling Fluid for Drilling in Marine Gas Hydrates-Bearing Sediments: An Experimental Study

    OpenAIRE

    Lixin Kuang; Yibing Yu; Yunzhong Tu; Ling Zhang; Fulong Ning; Guosheng Jiang; Tianle Liu

    2011-01-01

    Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experimental gas-hydrate integrated simulation system developed by our laboratory. The results of these tests show that drilling fluid with a formulation of artificial seawater, 3% bentonite, 0.3% Na 2 CO 3 , 10% polyethylene glycol, 20% NaCl, 4% SMP-2, 1% ...

  9. Rheological behavior of fumed silica suspension in polyethylene glycol

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The rheological behavior of fumed silica suspensions in polyethylene glycol(PEG) was studied at steady and oscillatory shear stress using AR 2000 stress controlled rheometer. The systems show reversible shear thickening behavior and the shear-thickening behavior can be explained by the clustering mechanism. The viscosity and the degree of shear-thickening of the systems strongly depend on the mass fraction of the silica, the molecular weigh of PEG and the frequency used in the rheological measurement. The silica volume fraction of the systems is 1.16 %-3.62%, corresponding to the mass fraction of 4%- 9 %. The shear-thickening taking place in the low volume fraction may contribute to the fractal nature of the silica. At oscillatory shear stress, when the shear stress is less than the critical stress, the storage modulus decreases significantly, meanwhile the loss modulus and the complex viscosity almost remain unchanged; when the shear stress is larger than the critical stress, the storage modulus, the loss modulus and the complex viscosity increase with the increase of shear stress. The loss modulus is larger than the storage modulus in the range of stress studied and both moduli depend on frequency.

  10. Surface modification of polypropylene membrane by polyethylene glycol graft polymerization.

    Science.gov (United States)

    Abednejad, Atiye Sadat; Amoabediny, Ghasem; Ghaee, Azadeh

    2014-09-01

    Polypropylene hollow fiber microporous membranes have been used in a wide range of applications, including blood oxygenator. The hydrophobic feature of the polypropylene surface causes membrane fouling. To minimize fouling, a modification consisting of three steps: surface activation in H2 and O2 plasma, membrane immersion in polyethylene glycol (PEG) and plasma graft polymerization was performed. The membranes were characterized by contact angle measurement, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Oxygen transfer of modified membranes was also tested. The stability of grafted PEG was measured in water and in phosphate buffer saline (PBS) at 37°C. Blood compatibility of modified surfaces was evaluated by the platelet adhesion method. Water contact angel reduction from 110° to 72° demonstrates the enhanced hydrophilicity, and XPS results verify the presence of oxygenated functional groups due to the peak existence in 286 eV as a result of PEG grafting. The results clearly indicate that plasma graft-polymerization of PEG is an effective way for antifouling improvement of polypropylene membranes. Also, the results show that oxygen transfer changes in PEG grafted membranes are not significant.

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

    Energy Technology Data Exchange (ETDEWEB)

    Engberg, Kristin; Frank, Curtis W, E-mail: curt.frank@stanford.edu [Department of Chemical Engineering, Stanford University, 381 North-South Mall, Stauffer III, Stanford, CA 94305 (United States)

    2011-10-15

    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{sub gel} = 0.16 {+-} 0.02 x 10{sup -8} cm{sup 2} s{sup -1}) and the fastest diffusion occurring through higher molecular weight, low-solid-content networks (D{sub gel} = 11.05 {+-} 0.43 x 10{sup -8} cm{sup 2} s{sup -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.

  12. Biological properties of adrenomedullin conjugated with polyethylene glycol.

    Science.gov (United States)

    Kubo, Keishi; Tokashiki, Mariko; Kuwasako, Kenji; Tamura, Masaji; Tsuda, Shugo; Kubo, Shigeru; Yoshizawa-Kumagaye, Kumiko; Kato, Johji; Kitamura, Kazuo

    2014-07-01

    Adrenomedullin (AM) is a vasodilator peptide with pleiotropic effects, including cardiovascular protection and anti-inflammation. Because of these beneficial effects, AM appears to be a promising therapeutic tool for human diseases, while intravenous injection of AM stimulates sympathetic nerve activity due to short-acting potent vasodilation, resulting in increased heart rate and renin secretion. To lessen these acute reactions, we conjugated the N-terminal of human AM peptide with polyethylene glycol (PEG), and examined the biological properties of PEGylated AM in the present study. PEGylated AM stimulated cAMP production, an intracellular second messenger of AM, in cultured human embryonic kidney cells expressing a specific AM receptor in a dose-dependent manner, as did native human AM. The pEC50 value of PEGylated AM was lower than human AM, but no difference was noted in maximum response (Emax) between the PEGylated and native peptides. Intravenous bolus injection of 10nmol/kg PEGylated AM lowered blood pressure in anesthetized rats, but the acute reduction became significantly smaller by PEGylation as compared with native AM. Plasma half-life of PEGylated AM was significantly longer than native AM both in the first and second phases in rats. In summary, N-terminal PEGylated AM stimulated cAMP production in vitro, showing lessened acute hypotensive action and a prolonged plasma half-life in comparison with native AM peptide in vivo.

  13. Mechanistic insights into acyclovir-polyethylene glycol 20000 binary dispersions

    Science.gov (United States)

    Venkateskumar, Krishnamoorthy; Parasuraman, Subramani; Gunasunderi, Raju; Sureshkumar, Krishnan; Nayak, M. Muralidhar; Shah, Syed Adnan Ali; Kassen, Khoo; Kai, Heng Wei

    2016-01-01

    Objective: The objective of this study is to provide a mechanistic insight into solubility enhancement and dissolution of acyclovir (ACY) by polyethylene glycol20000 (PEG20000). Materials and Methods: Solid dispersions with differing ratios of drug (ACY) and carrier (PEG20000) were prepared and evaluated by phase solubility, in vitro release studies, kinetic analysis, in situ perfusion, and in vitro permeation studies. Solid state characterization was also done by Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared spectroscopy (FT-IR) analysis and surface morphology was assessed by Polarizing Microscopic Image (PMI) analysis, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and Nuclear Magnetic Resonance (NMR) analysis. Results: Thermodynamic parameters proved the solubilization effect of carrier. The aqueous solubility and dissolution of ACY were increased in all samples. Formation of solid solution, crystallinity reduction, and absence of interaction between drug and carrier was proved by XRD, DSC, and FTIR analysis. The particle size reduction and change in surface morphology were confirmed by SEM and AFM and analysis. The permeation coefficient and amount of drug diffused was higher in samples as compared to ACY. The stability was high in dispersions, and it was proved by NMR analysis. Conclusion: The mechanical insights into the enhancement of solubility and dissolution could be used as a platform to improve the aqueous solubility for other poor water soluble drugs. PMID:28123988

  14. Preliminary investigation of a polyethylene glycol hydrogel "nerve glue"

    Directory of Open Access Journals (Sweden)

    McDaniel Candice

    2009-09-01

    Full Text Available Abstract Background Polyethylene glycol (PEG hydrogel is a biocompatible semi-adherent gel like substance that can potentially augment nerve repair much like a fibrin sealant. Potential advantages of this substance include fast preparation and set up time, as well as adhesion inhibiting properties. The purpose of this study was to perform an initial evaluation of PEG hydrogel in this application. Methods The sciatic nerves of 29 rats were transected and repaired using two 10-0 nylon sutures and either PEG hydrogel or fibrin glue. After 10 weeks, contraction forces of the reinnervated muscles were evaluated and histological assessment of scar tissue performed. Results Muscle strength testing revealed the average ratio of experimental to control sides for the fibrin glue group was 0.75 and for the PEG hydrogel group was 0.72 (no significant difference. Longitudinal sections through the nerve repair site showed no significant difference in nerve diameter but did demonstrate a significant reduction in scar thickness in the PEG hydrogel group (p Conclusion Though further study is necessary to fully evaluate, PEG hydrogel results in less scar tissue formation and equivalent muscle recovery as fibrin sealant when applied as a nerve glue in a rodent sciatic nerve repair model.

  15. Degradation of polyethylene glycol by Fenton reaction: a comparative study.

    Science.gov (United States)

    Haseneder, R; Fdez-Navamuel, B; Härtel, G

    2007-01-01

    Photochemical advanced oxidation processes (AOPs) utilising different Fenton systems were investigated in laboratory-scale experiments for the degradation of polyethylene glycol (PEG). The results of the study showed that the degradation rate of PEG was strongly accelerated by the homogeneous system, and this proved to be advantageous in comparison to the heterogeneous system. Between Fenton and photo-Fenton heterogeneous systems, the photo-Fenton process reached the highest removal rate of the organic compound, due to the enhanced reduction efficiency of Fe(III) to Fe(II) under UV-irradiation. The oxidation rate in the heterogeneous system was investigated using varying different parameters, such as the pH value, the concentration of hydrogen peroxide and the amount of Fe(OH)3 as the catalyst. For the homogeneous Fenton system the rate of degradation is significantly higher. At the same time of operation the elimination rates can be found to be 30% over the rates of the heterogeneous system. Optimising the typical influence parameters mentioned before, a degradation of about 93% of PEG can be achieved by using the homogeneous Fenton system.

  16. Green polymer chemistry VIII: synthesis of halo-ester-functionalized poly(ethylene glycol)s via enzymatic catalysis.

    Science.gov (United States)

    Castano, Marcela; Seo, Kwang Su; Kim, Eun Hye; Becker, Matthew L; Puskas, Judit E

    2013-09-01

    Halo-ester-functionalized poly(ethylene glycol)s (PEGs) are successfully prepared by the transesterification of alkyl halo-esters with PEGs using Candida antarctica lipase B (CALB) as a biocatalyst under the solventless conditions. Transesterifications of chlorine, bromine, and iodine esters with tetraethylene glycol monobenzyl ether (BzTEG) are quantitative in less than 2.5 h. The transesterification of halo-esters with PEGs are complete in 4 h. (1) H and (13) C NMR spectroscopy with MALDI-ToF and ESI mass spectrometry confirm the structure and purity of the products. This method provides a convenient and "green" process to effectively produce halo-ester PEGs.

  17. Surface modification of poly(ethylene terephthalate) by plasma polymerization of poly(ethylene glycol).

    Science.gov (United States)

    Sakthi Kumar, D; Fujioka, Masayori; Asano, Kentaro; Shoji, Atsumu; Jayakrishnan, Athipettah; Yoshida, Yasuhiko

    2007-09-01

    Poly(ethylene glycol) (PEG) was 'polymerized' onto poly(ethylene terephthalate) (PET) surface by radio frequency (RF) plasma polymerization of PEG (average molecular weight 200 Da) at a monomer vapour partial pressure of 10 Pa. Thin films strongly adherent onto PET could be produced by this method. The modified surface was characterized by infra red (IR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), cross-cut test, contact angle measurements and static platelet adhesion studies. The modified surface, believed to be extensively cross-linked, however showed all the chemical characteristics of PEG. The surface was found to be highly hydrophilic as evidenced by an interfacial free energy of about 0.7 dynes/cm. AFM studies showed that the surface of the modified PET became smooth by the plasma polymerized deposition. Static platelet adhesion studies using platelet rich plasma (PRP) showed considerably reduced adhesion of platelets onto the modified surface by SEM. Plasma 'polymerization' of a polymer such as PEG onto substrates may be a novel and interesting strategy to prepare PEG-like surfaces on a variety of substrates since the technique allows the formation of thin, pin-hole free, strongly adherent films on a variety of substrates.

  18. The effect of polyethylene glycol on the characteristics of kenaf cellulose/low-density polyethylene biocomposites.

    Science.gov (United States)

    Tajeddin, Behjat; Rahman, Russly Abdul; Abdulah, Luqman Chuah

    2010-08-01

    Toward the development of biocomposites for packaging applications, the possibility of using kenaf cellulose (KC) was investigated in the production of low-density polyethylene (LDPE)/KC/polyethylene glycol (PEG) biocomposites. First, cellulose was extracted from the cell walls of kenaf-bast fibers. Then, different weights of LDPE, KC, and PEG were blended, and the effects of varying the concentrations of KC and PEG on the synthesis process were evaluated, and the resulting composites were characterized with respect to their mechanical, thermal, biodegradability and water-absorption properties. A scanning electron microscope (SEM) was also used to observe the surface morphology of the samples before and after biodegradation tests. The results showed that the mechanical properties of the biocomposites decreased slightly as the KC content was increased from 0 to 50wt% in the biocomposite formulation; however, there was a good homogeneity between samples with added PEG. The addition of KC improved the thermal resistance of these biocomposites; PEG also had positive role in the thermal behavior of the composites. Based on a soil-burial test, the biodegradability of the composites showed a clear trend of increase degradation with increasing KC content in the formulation. While water-absorption values for the composites were higher than that of pure LDPE polymer, the addition of PEG to the formulation reduced the water absorption of the composites.

  19. Separation of polyethylene glycols and amino-terminated polyethylene glycols by high-performance liquid chromatography under near critical conditions.

    Science.gov (United States)

    Wei, Y-Z; Zhuo, R-X; Jiang, X-L

    2016-05-20

    The separation and characterization of polyethylene glycols (PEGs) and amino-substituted derivatives on common silica-based reversed-phase packing columns using isocratic elution is described. This separation is achieved by liquid chromatography under the near critical conditions (LCCC), based on the number of amino functional end groups without obvious effect of molar mass for PEGs. The mobile phase is acetonitrile in water with an optimal ammonium acetate buffer. The separation mechanism of PEG and amino-substituted PEG under the near LCCC on silica-based packing columns is confirmed to be ion-exchange interaction. Under the LCCC of PEG backbone, with fine tune of buffer concentration, the retention factor ratios for benzylamine and phenol in buffered mobile phases, α(benzylamine/phenol)-values, were used to assess the ion-exchange capacity on silica-based reversed-phase packing columns. To the best of our knowledge, this is the first report on separation of amino-functional PEGs independent of the molar mass by isocratic elution using common C18 or phenyl reversed-phase packing columns.

  20. The "New Polyethylene Glycol Dilemma": Polyethylene Glycol Impurities and Their Paradox Role in mAb Crystallization.

    Science.gov (United States)

    Hildebrandt, Christian; Joos, Lea; Saedler, Rainer; Winter, Gerhard

    2015-06-01

    Polyethylene glycols (PEG) represent the most successful and frequently applied class of excipients used for protein crystallization. PEG auto-oxidation and formation of impurities such as peroxides and formaldehydes that foster protein drug degradation is known. However, their effect on mAb crystallization has not been studied in detail before. During the present study, a model IgG1 antibody (mAb1) was crystallized in PEG solutions. Aggregate formation was observed during crystallization and storage that was ascribed to PEG degradation products. Reduction of peroxide and formaldehyde levels prior to crystallization by vacuum and freeze-drying was investigated for its effect on protein degradation. Vacuum drying was superior in removal of peroxides but inferior in reducing formaldehyde residues. Consequently, double purification allowed extensive removal of both impurities. Applying of purified PEG led to 50% lower aggregate fractions. Surprisingly, PEG double purification or addition of methionine prior to crystallization prevented crystal formation. With increased PEG concentration or spiking with peroxides and formaldehydes, crystal formation could be recovered again. With these results, we demonstrate that minimum amounts of oxidizing impurities and thus in consequence chemically altered proteins are vital to initiate mAb1 crystallization. The present study calls PEG as good precipitant for therapeutic biopharmaceuticals into question.

  1. AN APPROACH TO SYNTHESIZE POLY(ETHYLENE GLYCOL)-b-POLY(ε-CAPROLACTONE) WITH TERMINAL AMINO GROUP via SCHIFF'S BASE AS AN INITIATOR

    Institute of Scientific and Technical Information of China (English)

    Li Chen; Xiu-li Zhuang; Guo-en Sun; Xue-si Chen; Xia-bin Jing

    2008-01-01

    A new method to synthesize a degradable terminal amino group-containing copolymer, poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG-PCL-NH2), was developed in the following three steps: (1) the ring-opening polymerization (ROP) of ε-caprolactone from the Schiff base prepared from benzaldehyde and ethanolamine (Ph-CH=NCH2CH2OH) used as an initiator to obtain heterobifunctional poly(ε-caprolactone) with one terminal Schiff base group and one hydroxyl group (HO-PCL-CH2CH2N = CH-Ph); (2) the coupling reaction of two reactive precursors, a hydroxy-terminated HO-PCL-CH2CH2N=CH-Ph and α-monocarboxy-ωmonomethoxy poly(ethylene glycol) (CMPEG) to synthesize MPEG-PCL-CH2CH2N=CH-Ph; (3) the conversion of the -N=CH-Ph end-group into NH2 end-group by acidification of acetic acid to obtain MPEG-PCL-NH2. The structures from the precursors to the terminal amino group-containing copolymer were confirmed by 1H-NMR and their molecular weights were measured by gel permeation chromatography. The amphiphilic terminal amino group-containing copolymer could self-assemble into micelles in an aqueous system with PCL block as the core and PEG block as the shell. The micelle formation of the terminal amino group-containing block copolymer was studied by fluorescent probe technique and the existence of critical micellar concentration (cmc) confirmed the amphiphilic nature of the resulting copolymer. ESEM and DLS analysis of the micelles revealed a homogeneous spherical morphology and a unimodal size distribution.

  2. Combined Low-Volume Polyethylene Glycol Solution Plus Stimulant Laxatives versus Standard-Volume Polyethylene Glycol Solution: A Prospective, Randomized Study of Colon Cleansing before Colonoscopy

    Directory of Open Access Journals (Sweden)

    Lawrence C Hookey

    2006-01-01

    Full Text Available INTRODUCTION: The effectiveness of polyethylene glycol solutions (PEG for colon cleansing is often limited by the inability of patients to drink adequate portions of the 4 L solution. The aim of the present study was to determine whether a reduced volume of PEG combined with stimulant laxatives would be better tolerated and as or more effective than the standard dose.

  3. SANS study of highly resilient poly(ethylene glycol) hydrogels.

    Science.gov (United States)

    Saffer, Erika M; Lackey, Melissa A; Griffin, David M; Kishore, Suhasini; Tew, Gregory N; Bhatia, Surita R

    2014-03-28

    Polymer networks are critically important for numerous applications including soft biomaterials, adhesives, coatings, elastomers, and gel-based materials for energy storage. One long-standing challenge these materials present lies in understanding the role of network defects, such as dangling ends and loops, developed during cross-linking. These defects can negatively impact the physical, mechanical, and transport properties of the gel. Here we report chemically cross-linked poly(ethylene glycol) (PEG) gels formed through a unique cross-linking scheme designed to minimize defects in the network. The highly resilient mechanical properties of these systems (discussed in a previous publication) [J. Cui, M. A. Lackey, A. E. Madkour, E. M. Saffer, D. M. Griffin, S. R. Bhatia, A. J. Crosby and G. N. Tew, Biomacromolecules, 2012, 13, 584-588], suggests that this cross-linking technique yields more homogeneous network structures. Four series of gels were formed based on chains of 35,000 g mol(-1), (35k), 12,000 g mol(-1) (12k) g mol(-1), 8000 g mol(-1) (8k) and 4000 g mol(-1) (4k) PEG. Gels were synthesized at five initial polymer concentrations ranging from 0.077 g mL(-1) to 0.50 g mL(-1). Small-angle neutron scattering (SANS) was utilized to investigate the network structures of gels in both D2O and d-DMF. SANS results show the resulting network structure is dependent on PEG length, transitioning from a more homogeneous network structure at high molecular weight PEG to a two phase structure at the lowest molecular weight PEG. Further investigation of the transport properties inherent to these systems, such as diffusion, will aid to further confirm the network structures.

  4. Myocardial matrix-polyethylene glycol hybrid hydrogels for tissue engineering

    Science.gov (United States)

    Grover, Gregory N.; Rao, Nikhil; Christman, Karen L.

    2014-01-01

    Similar to other protein-based hydrogels, extracellular matrix (ECM) based hydrogels, derived from decellularized tissues, have a narrow range of mechanical properties and are rapidly degraded. These hydrogels contain natural cellular adhesion sites, form nanofibrous networks similar to native ECM, and are biodegradable. In this study, we expand the properties of these types of materials by incorporating poly(ethylene glycol) (PEG) into the ECM network. We use decellularized myocardial matrix as an example of a tissue specific ECM derived hydrogel. Myocardial matrix-PEG hybrids were synthesized by two different methods, cross-linking the proteins with an amine-reactive PEG-star and photo-induced radical polymerization of two different multi-armed PEG-acrylates. We show that both methods allow for conjugation of PEG to the myocardial matrix by gel electrophoresis and infrared spectroscopy. Scanning electron microscopy demonstrated that the hybrid materials still contain a nanofibrous network similar to unmodified myocardial matrix and that the fiber diameter is changed by the method of PEG incorporation and PEG molecular weight. PEG conjugation also decreased the rate of enzymatic degradation in vitro, and increased material stiffness. Hybrids synthesized with amine-reactive PEG had gelation rates of 30 min, similar to the unmodified myocardial matrix, and incorporation of PEG did not prevent cell adhesion and migration through the hydrogels, thus offering the possibility to have an injectable ECM hydrogel that degrades more slowly in vivo. The photo-polymerized radical systems gelled in 4 min upon irradiation, allowing 3D encapsulation and culture of cells, unlike the soft unmodified myocardial matrix. This work demonstrates that PEG incorporation into ECM-based hydrogels can expand material properties, thereby opening up new possibilities for in vitro and in vivo applications.

  5. Polyethylene glycol restores axonal conduction after corpus callosum transection.

    Science.gov (United States)

    Bamba, Ravinder; Riley, D Colton; Boyer, Richard B; Pollins, Alonda C; Shack, R Bruce; Thayer, Wesley P

    2017-05-01

    Polyethylene glycol (PEG) has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA) were used to measure mean firing rate (MFR) and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups (P < 0.01, P < 0.05). These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

  6. Polyethylene glycol restores axonal conduction after corpus callosum transection

    Directory of Open Access Journals (Sweden)

    Ravinder Bamba

    2017-01-01

    Full Text Available Polyethylene glycol (PEG has been shown to restore axonal continuity after peripheral nerve transection in animal models. We hypothesized that PEG can also restore axonal continuity in the central nervous system. In this current experiment, coronal sectioning of the brains of Sprague-Dawley rats was performed after animal sacrifice. 3Brain high-resolution microelectrode arrays (MEA were used to measure mean firing rate (MFR and peak amplitude across the corpus callosum of the ex-vivo brain slices. The corpus callosum was subsequently transected and repeated measurements were performed. The cut ends of the corpus callosum were still apposite at this time. A PEG solution was applied to the injury site and repeated measurements were performed. MEA measurements showed that PEG was capable of restoring electrophysiology signaling after transection of central nerves. Before injury, the average MFRs at the ipsilateral, midline, and contralateral corpus callosum were 0.76, 0.66, and 0.65 spikes/second, respectively, and the average peak amplitudes were 69.79, 58.68, and 49.60 μV, respectively. After injury, the average MFRs were 0.71, 0.14, and 0.25 spikes/second, respectively and peak amplitudes were 52.11, 8.98, and 16.09 μV, respectively. After application of PEG, there were spikes in MFR and peak amplitude at the injury site and contralaterally. The average MFRs were 0.75, 0.55, and 0.47 spikes/second at the ipsilateral, midline, and contralateral corpus callosum, respectively and peak amplitudes were 59.44, 45.33, 40.02 μV, respectively. There were statistically differences in the average MFRs and peak amplitudes between the midline and non-midline corpus callosum groups (P < 0.01, P < 0.05. These findings suggest that PEG restores axonal conduction between severed central nerves, potentially representing axonal fusion.

  7. Colonoscopy Preparation: Polyethylene Glycol with Gatorade is as Safe and Efficacious as 4 Liters of Polyethylene Glycol with Balanced Electrolytes

    Science.gov (United States)

    McKenna, Thomas; Macgill, Alice; Porat, Gail; Friedenberg, Frank K.

    2013-01-01

    Background Four liters of polyethylene glycol 3350 with balanced electrolytes for colonoscopy preparation has had poor acceptance. Another approach is the use of electrolyte-free PEG combined with 1.9L of Gatorade. Despite its widespread use, there are no data on metabolic safety and minimal data on efficacy. Our aim was to assess the efficacy and electrolyte safety of these two PEG-based preparations. Methods This was a prospective, randomized, single-blind, non-inferiority trial. Patients were randomized to 238g PEG + 1.9L Gatorade or 4L of PEG-ELS containing 236g PEG. Split dosing was not performed. On procedure day blood was drawn for basic chemistries. The primary outcome was preparation quality from procedure photos using the Boston Bowel Preparation Scale. Results We randomized 136 patients (66 PEG + Gatorade, 70 PEG-ELS). There were no differences in preparation scores between the two agents in the ITT analysis (7.2 ± 1.9 for PEG-ELS and 7.0 ± 2.1 for PEG + Gatorade; p = 0.45). BBPS scores were identical for those who completed the preparation and dietary instructions as directed (7.4 ± 1.7 for PEG-ELS, and 7.4 ± 1.8 for PEG + Gatorade; p = 0.98). There were no statistical differences in serum electrolytes between the two preparations. Patients who received PEG + Gatorade gave higher overall satisfaction scores for the preparation experience (p = 0.001), and had fewer adverse effects. Conclusions Use of 238g PEG + 1.9L Gatorade appears to be safe, better tolerated, and non-inferior to 4L PEG-ELS. This preparation may be especially useful for patients who previously tolerated PEG-ELS poorly. PMID:22711499

  8. Colonoscopy preparation: polyethylene glycol with Gatorade is as safe and efficacious as four liters of polyethylene glycol with balanced electrolytes.

    Science.gov (United States)

    McKenna, Thomas; Macgill, Alice; Porat, Gail; Friedenberg, Frank K

    2012-12-01

    Four liters of polyethylene glycol 3350 (PEG) with balanced electrolytes for colonoscopy preparation has had poor acceptance. Another approach is the use of electrolyte-free PEG combined with 1.9 L of Gatorade. Despite its widespread use, there are no data on metabolic safety and minimal data on efficacy. Our aim was to assess the efficacy and electrolyte safety of these two PEG-based preparations. This was a prospective, randomized, single-blind, non-inferiority trial. Patients were randomized to 238 g PEG + 1.9 L Gatorade or 4 L of PEG-ELS containing 236 g PEG. Split dosing was not performed. On procedure day blood was drawn for basic chemistries. The primary outcome was preparation quality from procedure photos using the Boston Bowel Preparation Scale. We randomized 136 patients (66 PEG + Gatorade, 70 PEG-ELS). There were no differences in preparation scores between the two agents in the ITT analysis (7.2 ± 1.9 for PEG-ELS and 7.0 ± 2.1 for PEG + Gatorade; p = 0.45). BBPS scores were identical for those who completed the preparation and dietary instructions as directed (7.4 ± 1.7 for PEG-ELS, and 7.4 ± 1.8 for PEG + Gatorade; p = 0.98). There were no statistical differences in serum electrolytes between the two preparations. Patients who received PEG + Gatorade gave higher overall satisfaction scores for the preparation experience (p = 0.001), and had fewer adverse effects. Use of 238 g PEG + 1.9 L Gatorade appears to be safe, better tolerated, and non-inferior to 4 L PEG-ELS. This preparation may be especially useful for patients who previously tolerated PEG-ELS poorly.

  9. Crystallization Kinetics of Indomethacin/Polyethylene Glycol Dispersions Containing High Drug Loadings.

    Science.gov (United States)

    Duong, Tu Van; Van Humbeeck, Jan; Van den Mooter, Guy

    2015-07-06

    The reproducibility and consistency of physicochemical properties and pharmaceutical performance are major concerns during preparation of solid dispersions. The crystallization kinetics of drug/polyethylene glycol solid dispersions, an important factor that is governed by the properties of both drug and polymer has not been adequately explored, especially in systems containing high drug loadings. In this paper, by using standard and modulated differential scanning calorimetry and X-ray powder diffraction, we describe the influence of drug loading on crystallization behavior of dispersions made up of indomethacin and polyethylene glycol 6000. Higher drug loading increases the amorphicity of the polymer and inhibits the crystallization of PEG. At 52% drug loading, polyethylene glycol was completely transformed to the amorphous state. To the best of our knowledge, this is the first detailed investigation of the solubilization effect of a low molecular weight drug on a semicrystalline polymer in their dispersions. In mixtures containing up to 55% indomethacin, the dispersions exhibited distinct glass transition events resulting from amorphous-amorphous phase separation which generates polymer-rich and drug-rich domains upon the solidification of supercooled polyethylene glycol, whereas samples containing at least 60% drug showed a single amorphous phase during the period in which crystallization normally occurs. The current study demonstrates a wide range in physicochemical properties of drug/polyethylene glycol solid dispersions as a result of the complex nature in crystallization of this system, which should be taken into account during preparation and storage.

  10. Poly(Ethylene Glycol-Based Backbones with High Peptide Loading Capacities

    Directory of Open Access Journals (Sweden)

    Aoife O'Connor

    2014-10-01

    Full Text Available Polymer-peptide conjugates are a promising class of compounds, where polymers can be used to overcome some of the limitations associated with peptides intended for therapeutic and/or diagnostic applications. Linear polymers such as poly(ethylene glycol can be conjugated through terminal moieties and have therefore limited loading capacities. In this research, functionalised linear poly(ethylene glycols are utilised for peptide conjugation, to increase their potential loading capacities. These poly(ethylene glycol derivatives are conjugated to peptide sequences containing representative side-chain functionalised amino acids, using different conjugation chemistries, including copper-catalysed azide-alkyne cycloaddition, amide coupling and thiol-ene reactions. Conjugation of a sequence containing the RGD motif to poly(allyl glycidyl ether by the thiol-ene reaction, provided a conjugate which could be used in platelet adhesion studies.

  11. Highly conductive polymer electrolyte membranes modified with polyethylene glycol-bis-carbamate

    Science.gov (United States)

    Fu, Guopeng; Dempsey, Janel; Kyu, Thein

    By virtue of its non-flammability and chemical stability, polyethylene glycol (PEG) networks have shown potential application in all solid-state polymer electrolyte membranes (PEM). However, room temperature ionic conductivity of these PEG based PEMs is inherently low. Plasticization of these PEMs is needed to improve the ionic conductivity. It was demonstrated by this group that small-molecule plasticizers such as succinonitrile, ethylene carbonate, or urea-carbamate can boost ionic conductivity of solid-state polymer electrolyte membranes. Polyethylene glycol bis-carbamate (PEGBC) was synthesized via condensation reaction of polyethylene glycol diamine and ethylene carbonate. The PEGBC modified PEM has shown higher ionic conductivity relative to the unmodified PEM. Moreover, PEGBC modified PEM has a better thermal stability relative to ethylene carbonate based liquid electrolyte with enhanced ionic conductivity. Supported by NSF-DMR 1161070, 1502543 and REU 1359321.

  12. FTIR studies on the effect of concentration of polyethylene glycol on polimerization of Shellac

    Science.gov (United States)

    Khairuddin; Pramono, E.; Utomo, S. B.; Wulandari, V.; Zahrotul W, A.; Clegg, F.

    2016-11-01

    In the present paper, it was reported the FTIR studies on the efect of polyethylene glycol on polimerization of shellac. The shellac was shellac waxfree, and the solvent was ethanol 96%. The shellac films were were prepared by solvent- evaporation method. The concentrations of polyethylene glycol having molecular weight of 400 were 10, 30, 60, and 90 w/w %. Three peak intensity bands of C= O stretching of ester at 1709 cm-1, O-H stretching of hydroxyl group at 3400 cm-1, and C-H stretching vibration at 2942 cm-1 were observed and related to polimerization of shellac. It was found that polymerization of shellac was slowed down by polyethyelene glycol, and the degree of polymerization of shellac decreased with increasing the concentration of polyethyelene glycol.

  13. Camomile autofermentation in polyethylene glycol/dextran two-phase system

    Directory of Open Access Journals (Sweden)

    Đaković Sanja D.

    2008-01-01

    Full Text Available The objective of this study was the investigation of the extractive bioconversion of apigenin-7-O-β-glucoside in camomile ligulate flowers into apigenin by autofermentation in polyethylene glycol 6000/dextran 200000 two-phase system. In 22.5% polyethylene glycol/14% dextran aqueous two-phase system the obtained yield of apigenin in the top phase was 96.5%. In the presence of plant material that partiotioned to the interphase, the yield of apigenin in the top phase was 3.5 times higher in comparison to the model system.

  14. Preparation of Iminodiacetic Acid-Polyethylene Glycol for Immobilized Metal Ion Affinity Partitioning

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The synthesis route was investigated and optimized for the preparation of iminodiacetic acid polyethylene glycol (IDA-PEG) for immobilized metal ion affinity partitioning in aqueous two-phaze systems. IDA PEG was synthesized from PEG in two steps by the reaction of iminodiacetic acid with a monosubetituted derivative of epichlorohydrin-activated PEG. The Cu2+ content combined with IDA-PEG was determined by atomic absorp tion spectrometry as 0.5 mol.mol-1 (PEG). Furthermore, the affinity partitioning behavior of lactate dehydrogenase in polyethylene glycol/hydroxypropyl starch aqueous two-phaze systems was studied to clarify the affinity effect of the Cu(Ⅱ)-IDA-PEG.

  15. The Determination of Polyethylene Glycol in Untreated Urine Samples by High Performance Liquid Chromatography for Intestinal Permeability Studies

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Pedersen, Walther Batsberg; Philipsen, E.

    1985-01-01

    Polyethylene glycol in urine samples has been investigated by high performance liquid chromatography. The molecular weights ranged from 634 to 1338. The urine samples were applied to the chromatographic system without any pre-treatment. For samples with a concentration of 0.2% polyethylene glycol...

  16. Platelet responses to dynamic biomaterial surfaces with different poly(ethylene glycol) and polyrotaxane molecular architectures constructed on gold substrates.

    Science.gov (United States)

    Kakinoki, Sachiro; Yui, Nobuhiko; Yamaoka, Tetsuji

    2013-11-01

    Four different dynamic biomaterial surfaces with different molecular architectures were prepared using two hydrophilic polymers: poly(ethylene glycol) and polyrotaxanes containing α-cyclodextrin. Either one or both terminals of the poly(ethylene glycol) or polyrotaxanes were immobilized onto a gold substrate via Au-S bonds, resulting in poly(ethylene glycol)-graft, polyrotaxanes-graft, poly(ethylene glycol)-loop, and polyrotaxanes-loop structures. Human platelet adhesion was suppressed more effectively on the graft surfaces than on the loop surfaces for both poly(ethylene glycol) and polyrotaxanes due to the high mobility of graft polymer chains with a free terminal. Moreover, the platelets adhered to the polyrotaxane surfaces much less than the poly(ethylene glycol) surfaces, possibly because of the mobile nature of the α-cyclodextrin molecules that were threaded on the poly(ethylene glycol) chain. Actin filament assembly in adherent platelets was also greatly prevented on the poly(ethylene glycol)/polyrotaxanes-graft surfaces in comparison with the corresponding loop surfaces. A clear correlation between the numbers and areas of adherent platelets on these surfaces suggests that platelet adhesion and activation were dominated by the platelet GPIIb/IIIa-adsorbed fibrinogen interaction. These results indicate that both of the different modes of dynamic features, sliding/rotation of α-cyclodextrin and polymer chain mobility, effectively suppressed platelet adhesion in spite of the similar hydrophilicity. This research affords a novel chemical strategy for designing hemocompatible biomaterial surfaces.

  17. 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 polystyrene-co

  18. MICROWAVE-ACCELERATED SUZUKI CROSS-COUPLING REACTION IN POLYETHYLENE GLYCOL (PEG)

    Science.gov (United States)

    Polyethylene glycol (PEG) is found to be an inexpensive and nontoxic reaction medium for the microwave-assisted Suzuki cross-coupling of arylboronic acids with aryl halides. This environmentally friendly microwave protocol offers the ease of operation and enables the recyclabilit...

  19. Accumulation of magnetic iron oxide nanoparticles coated with variably sized polyethylene glycol in murine tumors

    DEFF Research Database (Denmark)

    Larsen, Esben Kjær Unmack; Nielsen, Thomas; Wittenborn, Thomas;

    2012-01-01

    polyethylene glycol (PEG). Despite its frequent use, the influence of PEG coatings on the physicochemical and biological properties of iron nanoparticles has hitherto not been studied in detail. To address this, we studied the effect of 333–20 000 Da PEG coatings that resulted in larger hydrodynamic size...

  20. The permeability of polyethylene glycol oligomers in the isolated perfused rat liver

    NARCIS (Netherlands)

    Mengelers, M.J.B.

    1995-01-01

    Processes occuring in the liver are very important for the description of the kinetic behaviour of drugs and compounds present in food. Therefore this research was focussed on dispersion and distribution processes occuring in the rat liver. Polyethylene glycols were used as test compounds because th

  1. Molar Mass and Second Virial Coefficient of Polyethylene Glycol by Vapor Pressure Osmometry

    Science.gov (United States)

    Schwinefus, Jeffrey J.; Checkal, Caleb; Saksa, Brian; Baka, Nadia; Modi, Kalpit; Rivera, Carlos

    2015-01-01

    In this laboratory experiment, students determine the number-average molar masses and second virial coefficients of polyethylene glycol (PEG) polymers ranging in molar mass from 200 to 1500 g mol[superscript -1] using vapor pressure osmometry (VPO). Students assess VPO in relation to accurate molar mass calculations of PEG polymers. Additionally,…

  2. Importance of poly(ethylene glycol) conformation for the synthesis of silver nanoparticles in aqueous solution

    Science.gov (United States)

    In the formation of silver nanoparticles (NPs) using silver nitrate in a poly(ethylene glycol) (PEG) aqueous solution, which acts as both a reducing and stabilizing agent, the PEG chain structure was found to play a significant role. Even though PEG 100 (100 kg/mol) has limited reducing sites of hyd...

  3. Diethylamine functionalized polyethylene glycol as a novel and efficient catalyst for Knoevenagel condensation

    Indian Academy of Sciences (India)

    Wen Ye; Hong Jiang; Xian-Cao Yang

    2011-05-01

    The Knoevenagel condensation of aromatic aldehydes with active methylene is an efficient reaction for carbon-carbon double bond formation. A rapid, efficient, and ecofriendly protocol for the Knoevenagel condensation of active methylene compounds with aldehydes has been developed with diethylamine functionalized polyethylene glycol-600 (PEG-600) as catalyst with good to excellent yields at room temperature without solvent.

  4. Laxative Treatment With Polyethylene Glycol Does Not Affect Lipid Absorption in Rats

    NARCIS (Netherlands)

    van der Wulp, Mariette Y. M.; Cuperus, Frans J. C.; Stellaard, Frans; van Dijk, Theo H.; Dekker, Jan; Rings, Edmond H. H. M.; Groen, Albert K.; Verkade, Henkjan J.

    2012-01-01

    Objectives: Polyethylene glycol (PEG) is a frequently used laxative agent. It is unknown, however, whether PEG affects the absorptive capacity of the intestine. Reduced lipid (dietary fat and cholesterol) absorption induced by long-term PEG treatment could negatively affect growth in children. We te

  5. Purification of papain by metal affinity partitioning in aqueous two-phase polyethylene glycol/sodium sulfate systems.

    Science.gov (United States)

    Jiang, Zhi-Guo; Zhang, Hai-De; Wang, Wei-Tao

    2015-05-01

    A simple and inexpensive aqueous two-phase affinity partitioning system using metal ligands was introduced to improve the selectivity of commercial papain extraction. Polyethylene glycol 4000 was first activated using epichlorohydrin, then it was covalently linked to iminodiacetic acid. Finally, the specific metal ligand Cu(2+) was attached to the polyethylene glycol-iminodiacetic acid. The chelated Cu(2+) content was measured by atomic absorption spectrometry as 0.88 mol/mol (polyethylene glycol). The effects on the purification at different conditions, including polyethylene glycol molecular weight (2000, 4000, and 6000), concentration of phase-forming components (polyethylene glycol 12-20% w/w and sodium sulfate 12-20%, w/w), metal ligand type, and concentration, system pH and the commercial papain loading on papain extraction, were systematically studied. Under optimum conditions of the system, i.e. 18% w/w sodium sulfate, 18% w/w polyethylene glycol 4000, 1% w/w polyethylene glycol-iminodiacetic acid-Cu(2+) and pH 7, a maximum yield of 90.3% and a degree of purification of 3.6-fold were obtained. Compared to aqueous two phase extraction without ligands, affinity partitioning was found to be an effective technique for the purification of commercial papain with higher extraction efficiency and degree of purification.

  6. Highly efficient synthesis of monodisperse poly(ethylene glycols) and derivatives through macrocyclization of oligo(ethylene glycols).

    Science.gov (United States)

    Zhang, Hua; Li, Xuefei; Shi, Qiuyan; Li, Yu; Xia, Guiquan; Chen, Long; Yang, Zhigang; Jiang, Zhong-Xing

    2015-03-16

    A macrocyclic sulfate (MCS)-based approach to monodisperse poly(ethylene glycols) (M-PEGs) and their monofunctionalized derivatives has been developed. Macrocyclization of oligo(ethylene glycols) (OEGs) provides MCS (up to a 62-membered macrocycle) as versatile precursors for a range of monofunctionalized M-PEGs. Through iterative nucleophilic ring-opening reactions of MCS without performing group protection and activation, a series of M-PEGs, including the unprecedented 64-mer (2850 Da), can be readily prepared. Synthetic simplicity coupled with versatility of this new strategy may pave the way for broader applications of M-PEGs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Ultrasound responsive block copolymer micelle of poly(ethylene glycol)-poly(propylene glycol) obtained through click reaction.

    Science.gov (United States)

    Li, Fayong; Xie, Chuan; Cheng, Zhengang; Xia, Hesheng

    2016-05-01

    The well-defined amphiphilic poly(ethylene glycol)-block-poly(propylene glycol) copolymer containing 1, 2, 3-triazole moiety and multiple ester bonds (PEG-click-PPG) was prepared by click reaction strategy. The PEG-click-PPG copolymer can self-assemble into spherical micelles in aqueous solution. It is found that high intensity focused ultrasound (HIFU) can open the copolymer PEG-click-PPG micelles and trigger the release of the payload in the micelle. The multiple ester bonds introduced in the junction point of the copolymer chain through click reactions were cleaved under HIFU, and leads to the disruption of the copolymer micelle and fast release of loaded cargo. The click reaction provides a convenient way to construct ultrasound responsive copolymer micelles with weak bonds. Copyright © 2015. Published by Elsevier B.V.

  8. Stainless steel modified with poly(ethylene glycol) can prevent protein adsorption but not bacterial adhesion

    DEFF Research Database (Denmark)

    Wei, Jiang; Bagge, Dorthe; Gram, Lone

    2003-01-01

    The surface of AISI 316 grade stainless steel (SS) was modified with a layer of poly(ethylene glycol) (PEG) (molecular weight 5000) with the aim of preventing protein adsorption and bacterial adhesion. Model SS substrates were first modified to introduce a very high density of reactive amine groups...... by the adsorption of branched poly(ethylenimine) (PEI) from water. Methoxy-terminated aldehyde-poly(ethylene glycol) (M-PEG-CHO) was then grafted onto the PEI layers using reductive amination at the lower critical solution temperature (LCST) of the PEG in order to optimize the graft density of the linear PEG chains...

  9. IONIC CONDUCTIVITY OF EPOXY NETWORK /POLYETHYLENE GLYCOL- LITHIUM PERCHLORATE COMPLEX IPN SYSTEM

    Institute of Scientific and Technical Information of China (English)

    PENG Xinsheng; SONG Yongxian; QI Yuchen; WU Shuyun; LI Lixia; CHEN Donglin

    1990-01-01

    In an attempt to prepare a polymeric solid electrolyte with both high ionic conductivity at ambient temperature and adequate mechanical strength, an ionic conducting IPN composed of bisphenol A epoxy resin/polyethylene glycol containing LiClO4 was synthesized. The dependence of conductivity was investigated as a function of salt content, composition and temperature. It has been revealed that a maximum of conductivity appeared when EO/Li=25, where EO denotes the -(CH2CH2O )- unit in polyethylene glycol, and that the temperature dependence of conductivity followed VTF equation,suggesting that the motion of ionic carriers resulted from the segmental motion of the polymer. When glycerol epoxy resin was used instead of bisphenol A epoxy, the ambient temperature (25 ℃ ) conductivity could somewhat further be raised up to 3×10-5 S/cm.

  10. Crosslinked polymer gel electrolytes based on polyethylene glycol methacrylate and ionic liquid for lithium battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Chen [ORNL; Sun, Xiao-Guang [ORNL; Dai, Sheng [ORNL

    2013-01-01

    Gel polymer electrolytes were synthesized by copolymerization polyethylene glycol methyl ether methacrylate with polyethylene glycol dimethacrylate in the presence of a room temperature ionic liquid, methylpropylpyrrolidinium bis(trifluoromethanesulfonyl)imide (MPPY TFSI). The physical properties of gel polymer electrolytes were characterized by thermal analysis, impedance spectroscopy, and electrochemical tests. The ionic conductivities of the gel polymer electrolytes increased linearly with the amount of MPPY TFSI and were mainly attributed to the increased ion mobility as evidenced by the decreased glass transition temperatures. Li||LiFePO4 cells were assembled using the gel polymer electrolytes containing 80 wt% MPPY TFSI via an in situ polymerization method. A reversible cell capacity of 90 mAh g 1 was maintained under the current density of C/10 at room temperature, which was increased to 130 mAh g 1 by using a thinner membrane and cycling at 50 C.

  11. Characteristic of hyaluronic acid derivative films cross-linked by polyethylene glycol of low water content

    Institute of Scientific and Technical Information of China (English)

    Chen Jinghua; Chen Jingtao; Xu Zheng; Gu Qisheng

    2008-01-01

    Objective: To test the characteristics of byaluronic acid (HA) derivative cross-linked by polyethylene glycol films of low water content. Methods: The cross-linked HA film with 200 μm thickness was got at atmospheric pressure at 25℃ for 5 d. After dried, cross-linked films of 10 mm×10 mm were weighed and immersed in phosphate buffered saline (PBS pH 7.45) at 37℃ for 24 h. Then the solution fraction and water content were estimated. Meanwhile, cross-linked HA derivative films were immersed in phosphate buffered saline (PBS: pH 7.45) at 37℃ for determined time and then implanted subcutaneously in the back of white rats to test in vitro or in vivo degradation characteristic. Results and Conclusion: HA hydrogel cross-linked by polyethylene glycol with water content is as low as 60% and this kind of HA derivative has a slow degradation rate.

  12. Ciprofloxacin in polyethylene glycol-coated liposomes: efficacy in rat models of acute or chronic Pseudomonas aeruginosa infection

    NARCIS (Netherlands)

    I.A.J.M. Bakker-Woudenberg (Irma); M.T. ten Kate (Marian); L. Guo; P. Working; J.W. Mouton (Johan)

    2002-01-01

    textabstractIn a previous study in experimental Klebsiella pneumoniae pneumonia, the therapeutic potential of ciprofloxacin was significantly improved by encapsulation in polyethylene glycol-coated ("pegylated") long-circulating (STEALTH) liposomes. Pegylated liposomal

  13. Ciprofloxacin in polyethylene glycol-coated liposomes: efficacy in rat models of acute or chronic Pseudomonas aeruginosa infection

    NARCIS (Netherlands)

    I.A.J.M. Bakker-Woudenberg (Irma); M.T. ten Kate (Marian); L. Guo; P. Working; J.W. Mouton (Johan)

    2002-01-01

    textabstractIn a previous study in experimental Klebsiella pneumoniae pneumonia, the therapeutic potential of ciprofloxacin was significantly improved by encapsulation in polyethylene glycol-coated ("pegylated") long-circulating (STEALTH) liposomes. Pegylated liposomal ciprofloxaci

  14. Doxycycline loaded poly(ethylene glycol) hydrogels for healing vesicant-induced ocular wounds

    OpenAIRE

    Anumolu, SivaNaga S.; DeSantis, Andrea S; Menjoge, Anupa R; Hahn, Rita A.; Beloni, John A; Gordon, Marion. K.; Sinko, Patrick J.

    2009-01-01

    Half mustard (CEES) and nitrogen mustard (NM) are commonly used surrogates and vesicant analogs of the chemical warfare agent sulfur mustard. In the current study, in situ forming poly(ethylene glycol) (PEG)-based doxycycline hydrogels are developed and evaluated for their wound healing efficacy in CEES and NM exposed rabbit corneas in organ culture. The hydrogels, characterized by UV-Vis spectrophotometry, rheometry, and swelling kinetics, showed that the hydrogels are optically transparent,...

  15. Exploiting Poly(ethylene glycol as a Matrix for Liquid-Phase Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Kim D. Janda

    2000-08-01

    Full Text Available Soluble polymer-supported chemistry is a technology that allows the blending of the benefits of polymer-supported synthesis and solution-phase chemistry. Herein, we describe our recent efforts in this area targeted at exploring the scope of poly(ethylene glycol (PEG as the matrix. Specifically we describe the use of PEG as a support for triphenyl phosphine and for the Stille reaction.

  16. Polyethylene glycol in water: A simple, efficient and green protocol for the synthesis of quinoxalines

    Indian Academy of Sciences (India)

    Hemant V Chavan; Laxman K Adsul; Babasaheb P Bandgar

    2011-07-01

    A variety of biologically important quinoxaline derivatives has been efficiently synthesized in excellent yields under extremely mild conditions using PEG-600 and water. This inexpensive, non-toxic, ecofriendly and readily available system efficiently condensed several aromatic as well as aliphatic 1,2-diketones with aromatic and aliphatic 1,2-diamines to afford the products in excellent yield. Polyethylene glycol (PEG) can be recovered and recycled.

  17. Structure, dynamics, and rheology of concentrated dispersions of poly(ethylene glycol)-grafted colloids

    OpenAIRE

    Zackrisson, Malin; Stradner, Anna; Schurtenberger, Peter; Bergenholtz, Johan

    2006-01-01

    A comprehensive experimental study of the dynamics and rheology of concentrated aqueous dispersions of poly(ethylene glycol)-grafted colloidal spheres is reported. The study focuses on good solvent conditions, for which excluded-volume interactions dominate. At high concentrations a glass transition is evident from the nondecaying component of the intensity correlation function measured with three-dimensional dynamic light scattering. Results for the linear viscoelastic and steady shear rheol...

  18. Patterned Array of Poly(ethylene glycol) Silane Monolayer for Label-Free Detection of Dengue

    OpenAIRE

    Nor Zida Rosly; Shahrul Ainliah Alang Ahmad; Jaafar Abdullah; Nor Azah Yusof

    2016-01-01

    In the present study, the construction of arrays on silicon for naked-eye detection of DNA dengue was demonstrated. The array was created by exposing a polyethylene glycol (PEG) silane monolayer to 254 nm ultraviolet (UV) light through a photomask. Formation of the PEG silane monolayer and photomodifed surface properties was thoroughly characterized by using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. The results of XPS confirmed that...

  19. Rapid Heterotrophic Ossification with Cryopreserved Poly(ethylene glycol-) Microencapsulated BMP2-Expressing MSCs

    OpenAIRE

    Jennifer Mumaw; Jordan, Erin T.; Corinne Sonnet; Olabisi, Ronke M.; Olmsted-Davis, Elizabeth A.; Davis, Alan R.; Peroni, John F.; West, Jennifer L.; Franklin West; Yangqing Lu; Stice, Steven L.

    2012-01-01

    Autologous bone grafting is the most effective treatment for long-bone nonunions, but it poses considerable risks to donors, necessitating the development of alternative therapeutics. Poly(ethylene glycol) (PEG) microencapsulation and BMP2 transgene delivery are being developed together to induce rapid bone formation. However, methods to make these treatments available for clinical applications are presently lacking. In this study we used mesenchymal stem cells (MSCs) due to their ease of har...

  20. Semi-interpenetrating polymer networks of chitosan and poly(ethylene glycol)

    OpenAIRE

    Milosavljević Nedeljko B.; Kalagasidis-Krušić Melina T.; Filipović Jovanka M.

    2008-01-01

    Chitosan is a natural polycationic polymer that possesses useful properties such as bioactivity, biocompatibility, non-toxicity and non-antigenicity. On the other hand, its mechanical properties are not good for some biomedical application. They may be improved by preparing semi-interpenetrating polymer networks (semi-IPNs), when the hydrogel network is prepared in the presence of a previously made polymer such as poly(ethylene glycol). This paper deals with synthesis and characterization of ...

  1. OPTIMIZATION AND CHARACTERIZATION OF POLYSULFONE MEMBRANES MADE OF ZINC OXIDE, POLYETHYLENE GLYCOL AND EUGENOL AS ADDITIVES

    OpenAIRE

    2016-01-01

    The aim of this study to investigate the effect of zinc oxide, polyethylene glycol (PEG) and eugenol on the properties of membranes made of polysulfone (PSf). Polysulfone membranes were prepared via phase inversion method using Nmethyl-2-pyrolidone (NMP) as a solvent and water as non-solvent. The membranes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), porosity, tensile strength, permeability, rejection and antibacterial te...

  2. Efficacy of polyethylene glycol 4000 on constipation of posttraumatic bedridden patients

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lian-yang; YAO Yuan-zhang; WANG Tao; FEI Jun; SHEN Yue; CHEN Yong-hua; ZONG Zhao-wen

    2010-01-01

    Objective:To investigate the efficacy and safety of polyethylene glycol 4000 (Forlax(R)) on adult patients with functional constipation due to posttraumatic confinement to bed.Methods: A total of 201 posttraumatic bedridden patients were studied in this prospective,open-labeled, singlegroup study. Polyethylene glycol 4000 was administered orally for 14 days and the dosage was adjusted according to the Bristol stool types. Demographic characteristics, disease status, treatment period and factors affecting clinical outcome, especially the concomitant medications, were recorded.Results:After administration of polyethylene glycol 4000, 194 cases (96.52%) showed remission of constipation,including 153 (76.12%)persistent remission. The average defecation frequency increased significantly after treatment and the percentage of patients with stools of normal types (Bristol types 3-5) increased as well. Genders, ages and concomitant medications showed no significant influence on the persistent remission rate. After consecutive treatment for two weeks, patients with slight movement showed a significantly higher remission rate than those without movement (95% vs 80%). At the end of treatment, most accompanying symptoms were relieved obviously. Patients with a medical history of constipation or ever taking laxatives showed a lower remission rate. Sixty cases (29.85%) developed diarrhea during the observational period, among whom 6 (10%) withdrew from the clinical observation voluntarily at the first onset of diarrhea. Two cases suffered from abdominal pain.Conclusions:Polyethylene glycol 4000 (Forlax(R)) has efficacy on functional constipation in posttraumatic bedridden patients. Furthermore, patients with milder symptoms,more movement in bed, and longer duration of treatment but without accompanying symptoms can achieve a higher remission rate.

  3. In Situ forming poly(ethylene glycol)-based hydrogels via thiol-maleimide Michael-type addition

    OpenAIRE

    Fu, Yao; Kao, Weiyuan John

    2011-01-01

    The incorporation of cells and sensitive compounds can be better facilitated without the presence of UV or other energy sources that are common in the formation of biomedical hydrogels such as poly(ethylene glycol) hydrogels. The formation of hydrogels by the step-growth polymerization of maleimide- and thiol-terminated poly(ethylene glycol) macromers via Michael-type addition is described. The effects of macromer concentration, pH, temperature, and the presence of biomolecule gelatin on gel ...

  4. The excluded volume effect induced by poly(ethylene glycol) modulates the motility of actin filaments interacting with myosin.

    Science.gov (United States)

    Munakata, Shinsuke; Hatori, Kuniyuki

    2013-11-01

    To examine the motility of actomyosin complexes in the presence of high concentrations of polymers, we investigated the effect of poly(ethylene glycol) on the sliding velocities of actin filaments and regulated thin filaments on myosin molecules in the presence of ATP. Increased concentrations and relative molecular masses of poly(ethylene glycol) decreased the sliding velocities of actin and regulated thin filaments. The decreased ratio of velocity in regulated thin filaments at - log[Ca(2+) ] of 4 was higher than that of actin filaments. Furthermore, in the absence of Ca(2+) , regulated thin filaments were moderately motile in the presence of poly(ethylene glycol). The excluded volume change (∆V), defined as the change in water volume surrounding actomyosin during the interactions, was estimated by determining the relationship between osmotic pressure exerted by poly(ethylene glycol) and the decreased ratio of the velocities in the presence and absence of poly(ethylene glycol). The ∆V increased up to 3.7 × 10(5) Å(3) as the Mr range of poly(ethylene glycol) was increased up to 20,000. Moreover, the ∆V for regulated thin filaments was approximately two-fold higher than that of actin filaments. This finding suggests that differences in the conformation of filaments according to whether troponin-tropomyosin complexes lie on actin filaments alter the ∆V during interactions of actomyosin complexes and influence motility. © 2013 FEBS.

  5. Mechanical, rheological, and bioactivity properties of ultra high-molecular-weight polyethylene bioactive composites containing polyethylene glycol and hydroxyapatite.

    Science.gov (United States)

    Ahmad, Mazatusziha; Uzir Wahit, Mat; Abdul Kadir, Mohammed Rafiq; Mohd Dahlan, Khairul Zaman

    2012-01-01

    Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA) as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P) precipitates on the composite surface as proven from SEM and XRD analysis.

  6. Mechanical, Rheological, and Bioactivity Properties of Ultra High-Molecular-Weight Polyethylene Bioactive Composites Containing Polyethylene Glycol and Hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Mazatusziha Ahmad

    2012-01-01

    Full Text Available Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P precipitates on the composite surface as proven from SEM and XRD analysis.

  7. CLOUD POINT CURVES OF POLY(ETHYLENE GLYCOL) / POLY(PROPYLENE GLYCOL) MIXTURES AND THEIR THERMODYNAMIC EXPLANATION

    Institute of Scientific and Technical Information of China (English)

    SUN Ruona; CHAI Zhikuan

    1988-01-01

    In the study of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) mixtures not only a bimodal shape but also a reverse trend of the dependence on molecular weight of the cloud point curves were observed.This trend indicates that the miscibility of the studied mixtures decreases as the molecular weight of one component decreases. The excess volumes of the mixtures show that the interaction parameter between two components decreases at first and increases after passing a minimum as the concentration of one component increases. This supports the explanation of Koningsveld on the bimodal shape of cloud point curves. Based on a binary interaction model a formula was derived revealing that the interaction between PPG and the end group of PEG and the hydrogen bonding interaction between ether and hydroxy end group inner or inter PEG molecules are not favorable for mixing. The latter interaction is an "attractive" force in PEG molecules. The two interactions are responsible for the observed abnormal dependence.

  8. Poly(ethylene glycol)-poly(lactic-co-glycolic acid) based thermosensitive injectable hydrogels for biomedical applications.

    Science.gov (United States)

    Alexander, Amit; Ajazuddin; Khan, Junaid; Saraf, Swarnlata; Saraf, Shailendra

    2013-12-28

    Stimuli triggered polymers provide a variety of applications related with the biomedical fields. Among various stimuli triggered mechanisms, thermoresponsive mechanisms have been extensively investigated, as they are relatively more convenient and effective stimuli for biomedical applications. In a contemporary approach for achieving the sustained action of proteins, peptides and bioactives, injectable depots and implants have always remained the thrust areas of research. In the same series, Poloxamer based thermogelling copolymers have their own limitations regarding biodegradability. Thus, there is a need to have an alternative biomaterial for the formulation of injectable hydrogel, which must remain biocompatible along with safety and efficacy. In the same context, poly(ethylene glycol) (PEG) based copolymers play a crucial role as a biomedical material for biomedical applications, because of their biocompatibility, biodegradability, thermosensitivity and easy controlled characters. This review stresses on the physicochemical property, stability and composition prospects of smart PEG/poly(lactic-co-glycolic acid) (PLGA) based thermoresponsive injectable hydrogels, recently utilized for biomedical applications. The manuscript also highlights the synthesis scheme and stability characteristics of these copolymers, which will surely help the researchers working in the same area. We have also emphasized the applied use of these smart copolymers along with their formulation problems, which could help in understanding the possible modifications related with these, to overcome their inherent associated limitations. © 2013.

  9. Poly(ethylene glycol-poly(tetrahydrofuran-poly(ethylene glycol triblock copolymer : Synthesis, crystallization behavior and novel morphology

    Directory of Open Access Journals (Sweden)

    X. Q. Liao

    2013-05-01

    Full Text Available Poly(ethylene glycol-poly(tetrahydrofuran-poly(ethylene glycol (PEG-PTHF-PEG triblock copolymer was synthesized by ring-opening polymerization of ethylene oxide using sodium alcoholate of PTHF as the macroinitiator. Its crystallization behavior and formation mechanisms of different crystal structures were studied. The study showed that the molecular weight of PEG-PTHF-PEG exhibited a significant effect on its crystallization: that is, with the increase of the copolymer’s molecular weight, the crystallizability of PTHF blocks decreased gradually, which led to the transition of copolymer from crystalline-crystalline to crystalline-amorphous. By adjusting the total molecular weight of triblock copolymer, the crystallization process can be effectively controlled, and as a result, different spherulite structures were obtained. Particularly, when PTHF blocks became amorphous, novel double concentric spherulites were observed. The morphological structures were studied by differential scanning calorimetry (DSC, Fourier transform infrared spectroscopy (FTIR, scanning electron microscope (SEM, polarized optical microscopy (POM, and its crystalline process was investigated.

  10. Shear-thickening behavior of modified silica nanoparticles in polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Yu Kejing; Cao Haijian, E-mail: caohaijian20010@163.com; Qian Kun; Sha Xiaofei; Chen Yanping [Jiangnan University, Key Laboratory of Eco-textiles, Ministry of Education (China)

    2012-03-15

    The surface of silica nanoparticles with an average diameter of 650 nm was modified by ball milling and chemical treatment with ethylene glycol (EG). The Fourier-transform infrared spectra and particle size analysis methods were used to characterize the modified silica nanoparticles. The morphologies of the silica nanoparticles before and after the different surface treatments were examined by transmission electron microscope, scanning electron microscope. The rheological behaviors of modified silica suspensions in polyethylene glycol were studied by using Anton-paar 301 stress-controlled rheometer. The results of rheological tests indicated that the surface treatments had a great effect on increasing the maximum weight fraction of silica nanoparticles in Shear-thickening fluids, especially treated by the chemical method with EG.

  11. Characterization, molecular dynamics, and encapsulation ability of β-cyclodextrin polymers crosslinked by polyethylene glycol.

    Science.gov (United States)

    Kono, Hiroyuki; Nakamura, Taichi; Hashimoto, Hisaho; Shimizu, Yuuichi

    2015-09-05

    A series of water-insoluble cyclodextrin polymers (CDP) was prepared by crosslinking β-cyclodextrin (CD) with polyethylene glycol diglycidyl ether (PEGDE). Similarly, a reference CDP was prepared using ethylene glycol diglycidyl ether (EGDE). Increasing the feed ratio of PEGDE to CD in the reaction mixture led to high degrees of crosslinking. Relaxation measurements revealed structural homogeneity among the CDPs, which exhibited mobilities that strongly depended on the chain lengths of the crosslinking agents. In addition, all the CDPs displayed high encapsulation abilities toward bisphenol A (BPA) in aqueous media. In particular, the CDP sample with a low degree of crosslinking by PEGDE showed the highest encapsulation ability toward BPA. In contrast, the CDP crosslinked by EGDE exhibited low encapsulation ability because its highly dense structure, which results from the short chain lengths of the crosslinking agents, hinders the penetration of BPA molecules.

  12. Plasma-modified and polyethylene glycol-grafted polymers for potential tissue engineering applications.

    Science.gov (United States)

    Svorcík, V; Makajová, Z; Kasálková-Slepicková, N; Kolská, Z; Bacáková, L

    2012-08-01

    Modified and grafted polymers may serve as building blocks for creating artificial bioinspired nanostructured surfaces for tissue engineering. Polyethylene (PE) and polystyrene (PS) were modified by Ar plasma and the surface of the plasma activated polymers was grafted with polyethylene glycol (PEG). The changes in the surface wettability (contact angle) of the modified polymers were examined by goniometry. Atomic Force Microscopy (AFM) was used to determine the surface roughness and morphology and electrokinetical analysis (Zeta potential) characterized surface chemistry of the modified polymers. Plasma treatment and subsequent PEG grafting lead to dramatic changes in the polymer surface morphology, roughness and wettability. The plasma treated and PEG grafted polymers were seeded with rat vascular smooth muscle cells (VSMCs) and their adhesion and proliferation were studied. Biological tests, performed in vitro, show increased adhesion and proliferation of cells on modified polymers. Grafting with PEG increases cell proliferation, especially on PS. The cell proliferation was shown to be an increasing function of PEG molecular weight.

  13. Application of Oral Lactulose in Combination With Polyethylene Glycol Electrolyte Powder for Colonoscopy Bowel Preparation in Patients With Constipation.

    Science.gov (United States)

    Lu, Juan; Cao, Qin; Wang, Xiaochun; Pu, Jianbin; Peng, Xuelian

    2016-01-01

    The aim of the study was to investigate the efficacy of combined application of lactulose oral solution and polyethylene glycol electrolyte powder compared with conventional method in preparing for colonoscopy bowel cleanliness in patients with constipation. Ninety patients, who had constipation and needed to have colonoscopy, were divided into study group and control group with 45 cases in each group, respectively. One day before the colonoscopy, patients in the experimental group were given lactulose oral solution and polyethylene glycol electrolyte powder, whereas the patients in the control group were given oral polyethylene glycol electrolyte powder only. The following parameters were then obtained: time of the first defecation (duration of the time from taking the drugs to the first bowel movement), defecation frequency, completion of bowel cleaning (duration from the first bowel movement to the stool becoming clear), and adverse reaction. Cleansing effect in the study group bowel preparation was significantly better than that in the control group (P 0.05). Combined application of lactulose oral solution and polyethylene glycol electrolyte powder is superior to the conventional method of polyethylene glycol electrolyte powder alone for colonoscopy bowel preparation in patients with constipation. Therefore, combined clinical application of the 2 compounds is strongly recommended for colonoscopy bowel preparation in patients with constipation.

  14. Poly(ethylene) glycol-capped silver and magnetic nanoparticles: synthesis, characterization, and comparison of bactericidal and cytotoxic effects.

    Science.gov (United States)

    Mandal, A; Sekar, S; Chandrasekaran, N; Mukherjee, A; Sastry, T P

    2013-11-01

    Silver and magnetic (Fe3O4) nanoparticles have attracted wide attention as novel antimicrobial agents due to their unique chemical and physical properties. In order to study the comparative effects on antibacterial and animal cytotoxicity, Staphylococcus aureus and NIH 3T3 fibroblasts were used, respectively. Both nanoparticles were synthesized via a novel matrix-mediated method using poly(ethylene) glycol. Formation of silver nanoparticles was confirmed by fluorescence and ultraviolet-visible spectroscopic techniques. The poly(ethylene) glycol-coated silver and Fe3O4 nanoparticles were characterized by scanning electron microscope, transmission electron microscope, zeta potential, particle size analysis, Fourier-transform infrared, X-ray diffraction, and X-ray photoelectron spectroscopy. The antimicrobial results indicate that both poly(ethylene) glycol-coated silver and Fe3O4 nanoparticles inhibited S. aureus growth at the concentrations of 5 and 10 µg/mL at all time points without showing any significant cytotoxicity on NIH 3T3 fibroblasts. The particle size of both the poly(ethylene) glycol-coated silver and Fe3O4 nanoparticles dominated in the range 10-15 nm, obtained by particle size analyzer. The poly(ethylene) glycol coating on the particles showed less aggregation of nanoparticles, as observed by scanning electron microscope and transmission electron microscope. The overall obtained results indicated that these two nanoparticles were stable and could be used to develop a magnetized antimicrobial scaffolds for biomedical applications.

  15. A Comparative Study on Magnetostructural Properties of Barium Hexaferrite Powders Prepared by Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    Zehra Durmus

    2014-01-01

    Full Text Available Nanocrystalline particles of barium hexaferrite were synthesized by a sol-gel combustion route using nitrate-citrate gels prepared from metal nitrates and citric acid solutions with Fe/Ba molar ratio 12. The present paper aims to study the effect of addition of polyethylene glycol (PEG solutions with different molecular weights (MW: 400, 2000, and 10.000 g/mol on magnetostructural properties of barium hexaferrite. The formation of the barium hexaferrite was inspected using X-ray diffraction (XRD analysis, Fourier transform infrared (FT-IR analysis, thermogravimetric (TGA analysis, scanning electron microscopy (SEM analysis and vibrating sample magnetometer (VSM analysis for magnetic measurements.

  16. Synthesis and Characterization of Storage Energy Materials Prepared from Nano-crystalline Cellulose/Polyethylene Glycol

    Institute of Scientific and Technical Information of China (English)

    Xiao Ping YUAN; En Yong DING

    2006-01-01

    This paper gives a brief report of the synthesis of a new kind of solid-solid phase change materials (SSPCMs), nano-crystalline cellulose/polyethylene glycol (NCC/PEG). These PCMs have very high ability for energy storage, and their enthalpies reach 103.8 J/g. They are composed of two parts, PEG as functional branches for energy storage, and NCC as skeleton. The flexible polymer PEG was grafted onto the surface of rigid powder of NCC by covalent bonds. The results of DSC, FT-IR were briefly introduced, and some comments were also given.

  17. Biofunctionalization of polyelectrolyte microcapsules with biotinylated polyethylene glycol-grafted liposomes.

    Science.gov (United States)

    Gao, Jie; Reibetanz, Uta; Venkatraman, Subbu; Neu, Björn

    2011-08-11

    Hollow polyelectrolyte microcapsules (PEMC) are prepared using layer-by-layer self-assembly of polyelectrolytes on melamine formaldehyde templates, followed by template dissolution, and subsequent coating with biotinylated polyethylene glycol-grafted liposomes. These potential site-specific carrier systems show a high specificity for NeutrAvidin binding and a strong resistance against unspecific protein binding. It is concluded that this design with NeutrAvidin as the outermost layer of such capsules provides an ideal platform for the biofunctionalization of PEMC as drug delivery systems or as artificial cell-like structures for biomimetic studies.

  18. Polyethylene glycol submucosal irrigation: a novel approach to improve visibility during endoscopic submucosal dissection

    Science.gov (United States)

    Arantes, Vitor; Toyonaga, Takashi; Piñeros, Elias Alfonso Forero

    2014-01-01

    In order to expand the availability of endoscopic submucosal dissection (ESD), measures to facilitate the procedure are necessary. When bleeding occurs, the examiner’s field of vision is critically impaired, and ESD becomes less efficient and more hazardous because of the presence of submucosal hematoma and covered blood clot. We propose the use of polyethylene glycol (PEG) irrigation as a simple and effective measure to improve visibility during submucosal dissection, particularly when bleeding occurs. PEG irrigation facilitates further dissection by allowing a better recognition of the submucosal fibers and muscularis propria layer. PMID:26134968

  19. Long-term hepatotoxicity of polyethylene-glycol functionalized multi-walled carbon nanotubes in mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Danying; Ji Zongfei; Shen Xizhong; Dong Ling; Gu Taoying [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Deng Xiaoyong; Wu Minghong; Liu Yuanfang, E-mail: dltalk@tom.com, E-mail: mhwu@staff.shu.edu.cn [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444 (China)

    2010-04-30

    The toxicity of polyethylene-glycol functionalized (PEGylated) multi-walled carbon nanotubes (MWCNTs) and non-PEGylated MWCNTs in vivo was evaluated and compared. Mice were exposed to MWCNTs by intravenous injection. The activity level of glutathione, superoxide dismutase and gene expression in liver, as well as some biochemical parameters and the tumor necrosis factor alpha level in blood were measured over 2 months. The pathological and electron micrographic observations of liver evidently indicate that the damage caused by non-PEGylated MWCNTs is slightly more severe than that of PEGylated MWCNTs, which means that PEGylation can partly, but not substantially, improve the in vivo biocompatibility of MWCNTs.

  20. Ionic conductivity and dielectric permittivity of polymer electrolyte plasticized with polyethylene glycol

    Science.gov (United States)

    Das, S.; Ghosh, A.

    2016-05-01

    We have studied ionic conductivity and dielectric permittivity of PEO-LiClO4 solid polymer electrolyte plasticized with polyethylene glycol (PEG). The temperature dependence of the ionic conductivity has been well interpreted using Vogel-Tamman-Fulcher equation. The maximum dielectric constant is observed for 30 wt. % of PEG content. To get further insights into the ion dynamics, the complex dielectric permittivity has been studied with Havriliak-Negami function. The variation of relaxation time with inverse temperature obtained from HN formalism follows VTF nature.

  1. Sugar-Responsive Pseudopolyrotaxane Composed of Phenylboronic Acid-Modified Polyethylene Glycol and γ-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Tomohiro Seki

    2015-03-01

    Full Text Available We have designed a sugar-responsive pseudopolyrotaxane (PPRX by combining phenylboronic acid-modified polyethylene glycol (PBA–PEG and γ-cyclodextrin. Phenylboronic acid (PBA was used as a sugar-recognition motif in the PPRX because PBA reacts with a diol portion of the sugar molecule and forms a cyclic ester. When D-fructose or D-glucose was added to a suspension of PPRX, PPRX disintegrated, depending on the concentration of the sugars. Interestingly, catechol does not show a response although catechol has a high affinity for PBA. We analyzed the response mechanism of PPRX by considering equilibria.

  2. Enzyme-Catalyzed Modifications of Polysaccharides and Poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    H. N. Cheng

    2012-06-01

    Full Text Available Polysaccharides are used extensively in various industrial applications, such as food, adhesives, coatings, construction, paper, pharmaceuticals, and personal care. Many polysaccharide structures need to be modified in order to improve their end-use properties; this is mostly done through chemical reactions. In the past 20 years many enzyme-catalyzed modifications have been developed to supplement chemical derivatization methods. Typical reactions include enzymatic oxidation, ester formation, amidation, glycosylation, and molecular weight reduction. These reactions are reviewed in this paper, with emphasis placed on the work done by the authors. The polymers covered in this review include cellulosic derivatives, starch, guar, pectin, and poly(ethylene glycol.

  3. Poly(ethylene glycol)-supported Liquid-phase Parallel Synthesis of Di(aryloxyacetyl)thiosemicarbazides

    Institute of Scientific and Technical Information of China (English)

    Xi Cun WANG; Jun Ke WANG; Zheng LI

    2004-01-01

    An efficient poly(ethylene glycol) (PEG)-supported liquid-phase parallel approach to di(aryloxyacetyl)thiosemicarbazides is described. PEG-bound phenol reacted with chloroacetic acid to afford PEG-bound phenyloxyacetic acid, which was readily converted into corresponding phenyloxyacetyl chloride. Subsequent nucleophilic substitution with ammonium thiocyanate followed by addition of aryloxyacetic acid hydrazides gave PEG-bound di(aryloxyacetyl)thiosemi- carbazides, which were easily cleaved to give the resulting library of 1-aryloxyacetyl-4-(4'- methoxylcarbonylphenyloxyacetyl)thiosemicarbazides in good to high yield and high purity.

  4. Effects of the molecular weight and the valency of guest-modified poly(ethylene glycol)s on the stability, size and dynamics of supramolecular nanoparticles

    NARCIS (Netherlands)

    Stoffelen, C.; Staltari-Ferraro, E.; Huskens, Jurriaan

    2015-01-01

    The influence of the polymer length and the valency of guest-modified poly(ethylene glycol) (PEG) on the stability, size tunability and formation dynamics of supramolecular nanoparticles (SNPs) has been studied. SNPs were formed by molecular recognition between multi- and monovalent supramolecular

  5. Variations in polyethylene glycol brands and their influence on the preparation process of hydrogel microspheres

    DEFF Research Database (Denmark)

    Wöhl-Bruhn, Stefanie; Bertz, Andreas; Kuntsche, Judith

    2013-01-01

    Hydrogel microspheres, e.g. for the use as protein carriers, can be prepared without the use of organic solvents via an emulsified aqueous two phase system (ATPS) that is based on two immiscible polymer solutions. The type and concentration of the polymers can affect the ATPS and finally the dist......Hydrogel microspheres, e.g. for the use as protein carriers, can be prepared without the use of organic solvents via an emulsified aqueous two phase system (ATPS) that is based on two immiscible polymer solutions. The type and concentration of the polymers can affect the ATPS and finally...... the distribution of incorporated drugs between the aqueous phases. For the preparation of hydrogel microspheres based on hydroxyethyl starch-hydroxyethyl methacrylate (HES-HEMA), hydroxyethyl starch-methacrylate (HES-MA), and hydroxyethyl starch-polyethylene glycol methacrylate (HES-P(EG)6MA), polyethylene glycol...... 12,000 (PEG 12,000) was used as second polymer. The particle size distribution and encapsulation efficiency of the microspheres depended dramatically on the type of PEG 12,000 that was used in the second phase of the ATPS. Analysis of different PEG 12,000 brands by various methods revealed...

  6. Polyethylene Glycol Drilling Fluid for Drilling in Marine Gas Hydrates-Bearing Sediments: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Lixin Kuang

    2011-01-01

    Full Text Available Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experimental gas-hydrate integrated simulation system developed by our laboratory. The results of these tests show that drilling fluid with a formulation of artificial seawater, 3% bentonite, 0.3% Na2CO3, 10% polyethylene glycol, 20% NaCl, 4% SMP-2, 1% LV-PAC, 0.5% NaOH and 1% PVP K-90 performs well in shale swelling and gas hydrate inhibition. It also shows satisfactory rheological properties and lubrication at temperature ranges from −8 °C to 15 °C. The PVP K-90, a kinetic hydrate inhibitor, can effectively inhibit gas hydrate aggregations at a dose of 1 wt%. This finding demonstrates that a drilling fluid with a high addition of NaCl and a low addition of PVP K-90 is suitable for drilling in natural marine gas-hydrate-bearing sediments.

  7. 1H-NMR characterization of poly(ethylene glycol) and polydimethylsiloxane copolymer

    Science.gov (United States)

    Zainuddin, Ain Athirah; Othaman, Rizafizah; Noor, Wan Syaidatul Aqma Wan Mohd; Anuar, Farah Hannan

    2016-11-01

    This paper describes the synthesis and characterization of poly(ethylene glycol) (PEG) and polydimethylsiloxane (PDMS) copolymers. The copolymers were synthesized by reacting hydroxyl group (-OH) of poly(ethylene glycol) (PEG) and polydimetylsiloxane (PDMS) with isocyanate group (R-N=C=O) of 1,6-hexamethylene diisocyanate (HMDI). The reaction was carried out at room temperature. The copolymers were synthesized in three different compositions which differ in molar ratios of PEG to PDMS. The ratios (PEG:PDMS) used were 2:6. 3:5 and 4:4. The formation of the copolymers was characterized by 1H Nuclear Magnetic Resonance (1H-NMR) for structural determination. The presence of proton signal at 4.80 ppm which belongs to the proton of urethane group indicates the formation of urethane links. The formation of urethane links showed that two homopolymers were linked together by HMDI to form longer copolymer chains. It is worth to note that the sequence of PEG and PDMS along the copolymer chain is random.

  8. Anhydric maleic functionalization and polyethylene glycol grafting of lactide-co-trimethylene carbonate copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, A.; Valle, L.; Franco, L. del [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Sarasua, J.R. [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain); Estrany, F. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J., E-mail: Jordi.Puiggali@upc.es [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain)

    2014-09-01

    Lactide and trimethylene carbonate copolymers were successfully grafted with polyethylene glycol via previous functionalization with maleic anhydride and using N,N′-diisopropylcarbodiimide as condensing agent. Maleinization led to moderate polymer degradation. Specifically, the weight average molecular weight decreased from 36,200 to 30,200 g/mol for the copolymer having 20 mol% of trimethylene carbonate units. Copolymers were characterized by differential scanning calorimetry, thermogravimetry and X-ray diffraction. Morphology of spherulites and lamellar crystals was evaluated with optical and atomic force microscopies, respectively. The studied copolymers were able to crystallize despite the randomness caused by the trimethylene carbonate units and the lateral groups. Contact angle measurements indicated that PEG grafted copolymers were more hydrophilic than parent copolymers. This feature justified that enzymatic degradation in lipase medium and proliferation of both epithelial-like and fibroblast-like cells were enhanced. Grafted copolymers were appropriate to prepare regular drug loaded microspheres by the oil-in-water emulsion method. Triclosan release from loaded microspheres was evaluated in two media. - Highlights: • Pegylated copolymers of lactide and trimethylene carbonate have been synthesized. • Grafting with polyethylene glycol was able via maleic anhydride functionalization. • Drug-loaded microspheres could be prepared from new pegylated copolymers. • Hydrophilicity of lactide/trimethylene carbonate copolymers increased by pegylation. • New pegylated copolymers supported cell adhesion and proliferation.

  9. Polyethylene glycol-grafted bovine pericardium: a novel hybrid tissue resistant to calcification.

    Science.gov (United States)

    Vasudev, S C; Chandy, T

    1999-02-01

    Calcification is a frequent cause of the clinical failure of bioprosthetic heart valves fabricated from glutaraldehyde pretreated bovine pericardium (GATBP). An investigation was made of the grafting of different molecular weight polyethylene glycol (PEG 600, 1500, 4000 and 6000) via glutaraldehyde (GA) linkages to bovine pericardium (BP) and of their stability and calcification. The process of the calcification profile was studied by in vitro experiments via incubating pericardial samples in a metastable solution of calcium phosphate. Calcification of bovine pericardium grafted with PEG 6000 was significantly decreased compared to low molecular weight PEG grafts or Sodium dodecyl sulphate- (SDS) and GA-treated tissues. The mechanical properties of these modified tissues after enzyme (Trypsin) digestion and calcification were investigated. The biocompatibility aspects of grafted tissues were also established by monitoring the platelet adhesion, octane contact angle and water of hydration. PEG 6000-grafted tissues retained the maximum strength in trypsin buffer and calcium phosphate solutions. Scanning electron micrographs revealed that the PEG-grafted bovine pericardium had substantially inhibited the platelet-surface attachment and their spreading. It is conceivable that high molecular weight polyethylene glycol-grafted pericardium (a hybrid tissue) may be a suitable calcium-resistant material for developing prosthetic valves due to their stability and biocompatibility.

  10. Cross-linked polystyrene sulfonic acid and polyethylene glycol as a low-fouling material.

    Science.gov (United States)

    Alghunaim, Abdullah; Zhang Newby, Bi-min

    2016-04-01

    A negatively charged hydrophilic low fouling film was prepared by thermally cross-linking a blend consisting of polystyrene sulfonic acid (PSS) and polyethylene glycol (PEG). The film was found to be stable by dip-washing. The fouling resistance of this material toward bacterial (Escherichia coli) and colloidal (polystyrene particles) attachment, non-specific protein (fibronectin) adsorption and cell (3T3 NIH) adhesion was evaluated and was compared with glass slides modified with polyethylene glycol (PEG) brushes, oxidized 3-mercaptopropyltrimethoxysilane (sulfonic acid, SA), and n-octadecyltrichlorosilane (OTS). The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory and thermodynamic models based on surface energy were used to explain the interaction behaviors of E. coli/polystyrene particles-substrate and protein-substrate interactions, respectively. The cross-linked PSS-PEG film was found to be slightly better than SA and PEG toward resisting non-specific protein adsorption, and showed comparable low attachment results as those of PEG toward particle, bacterial and NIH-3T3 cells adhesion. The low-fouling performance of PSS-PEG, a cross-linked film by a simple thermal curing process, could allow this material to be used for applications in aqueous environments, where most low fouling hydrophilic polymers, such as PSS or PEG, could not be easily retained.

  11. Acoustic, Thermal and Molecular Interactions of Polyethylene Glycol (2000, 3000, 6000)

    Science.gov (United States)

    Venkatramanan, K.; Padmanaban, R.; Arumugam, V.

    Polyethylene Glycol (PEG) is a condensation polymer of ethylene oxide and water. PEG find its application as emulsifying agents, detergents, soaps, plasticizers, ointments, etc. Though the chemical and physical properties of PEG are known, still because of their uses in day to day life, it becomes necessary to study few physical properties like ultrasonic velocity, viscosity and hence adiabatic compressibility, free length, etc. In the present study, an attempt has been made to compute the activation energy and hence to analyse the molecular interactions of aqueous solutions of Polyethylene Glycol of molar mass 2000, 3000 and 6000 at different concentrations (2%, 4%, 6%, 8% and 10%) at different temperatures (303K, 308K, 313K, 318K) by determining relative viscosity, ultrasonic velocity and density. Various parameters like adiabatic compressibility, viscous relaxation time, inter molecular free length, free volume, internal pressure, etc are calculated at 303K and the results are discussed in the light of polymer-solvent interaction. This study helps to understand the behavior of macro-molecules with respect to changing concentration and temperature. Furthermore, viscosity and activation energy results are correlated to understand the increased entanglement of the polymer chains due to the increase in the concentration of a polymer solution that leads to an increase in viscosity and an increase in the activation energy of viscous flow.

  12. Impact of polyethylene glycol on porosity and microstructure of sand-lime product

    Directory of Open Access Journals (Sweden)

    Kostrzewa Paulina

    2016-01-01

    Full Text Available Autoclaved sand-lime products are environment-friendly building materials in the form of bricks and blocks. Due to great interest in silicate products, there have been numerous studies and modifications aimed at improving the properties of the material. The article presents the most important characteristics of sand-lime products, both traditional as well as modified with polyethylene glycol. The purpose of described research was to estimate porosity (determine the type, size and pores distribution and to analyze the microstructure of aforementioned samples. From the practical point of view, these characteristics are particularly important in the construction materials. The following tests have been carried out: bulk density using the hydrostatic method, capillarity, water absorption and mercury porosimetry of samples containing polyethylene glycol. The samples were also subjected to observation of the microstructure under the scanning electron microscope. Preliminary research findings clearly show the positive influence of the used substrate on the basic properties of modified sand-lime product. In comparison to the reference sample, modified products showed a decrease in water absorption and reduced capillarity. The confrontation of the measurements made using a mercury porosimeter with observation of the microstructure, showed differences in the distribution of pores and their size. Besides the additive, the production process itself has a huge impact on the properties of silicates (mixing process, time and temperature of autoclaving.

  13. Utilization of Triton X-100 and polyethylene glycols during surfactant-mediated biodegradation of diesel fuel.

    Science.gov (United States)

    Wyrwas, Bogdan; Chrzanowski, Łukasz; Ławniczak, Łukasz; Szulc, Alicja; Cyplik, Paweł; Białas, Wojciech; Szymański, Andrzej; Hołderna-Odachowska, Aleksandra

    2011-12-15

    The hypothesis regarding preferential biodegradation of surfactants applied for enhancement of microbial hydrocarbons degradation was studied. At first the microbial degradation of sole Triton X-100 by soil isolated hydrocarbon degrading bacterial consortium was confirmed under both full and limited aeration with nitrate as an electron acceptor. Triton X-100 (600 mg/l) was utilized twice as fast for aerobic conditions (t(1/2)=10.3h), compared to anaerobic conditions (t(1/2)=21.8h). HPLC/ESI-MS analysis revealed the preferential biodegradation trends in both components classes of commercial Triton X-100 (alkylphenol ethoxylates) as well as polyethylene glycols. The obtained results suggest that the observed changes in the degree of ethoxylation for polyethylene glycol homologues occurred as a consequence of the 'central fission' mechanism during Triton X-100 biodegradation. Subsequent experiments with Triton X-100 at approx. CMC concentration (150 mg/l) and diesel oil supported our initial hypothesis that the surfactant would become the preferred carbon source even for hydrocarbon degrading bacteria. Regardless of aeration regimes Triton X-100 was utilized within 48-72 h. Efficiency of diesel oil degradation was decreased in the presence of surfactant for aerobic conditions by approx. 25% reaching 60 instead of 80% noted for experiments without surfactant. No surfactant influence was observed for anaerobic conditions.

  14. Engineering of poly(ethylene glycol chain-tethered surfaces to obtain high-performance bionanoparticles

    Directory of Open Access Journals (Sweden)

    Yukio Nagasaki

    2010-01-01

    Full Text Available A poly(ethylene glycol-b-poly[2-(N,N-dimethylaminoethyl methacrylate] block copolymer possessing a reactive acetal group at the end of the poly(ethylene glycol (PEG chain, that is, acetal-PEG-b-PAMA, was synthesized by a proprietary polymerization technique. Gold nanoparticles (GNPs were prepared using the thus-synthesized acetal-PEG-b-PAMA block copolymer. The PEG-b-PAMA not only acted as a reducing agent of aurate ions but also attached to the nanoparticle surface. The GNPs obtained had controlled sizes and narrow size distributions. They also showed high dispersion stability owing to the presence of PEG tethering chains on the surface. The same strategy should also be applicable to the fabrication of semiconductor quantum dots and inorganic porous nanoparticles. The preparation of nanoparticles in situ, i.e. in the presence of acetal-PEG-b-PAMA, gave the most densely packed polymer layer on the nanoparticle surface; this was not observed when coating preformed nanoparticles. PEG/polyamine block copolymer was more functional on the metal surface than PEG/polyamine graft copolymer, as confirmed by angle-dependent x-ray photoelectron spectroscopy. We successfully solubilized the C60 fullerene into aqueous media using acetal-PEG-b-PAMA. A C60/acetal-PEG-b-PAMA complex with a size below 5 nm was obtained by dialysis. The preparation and characterization of these materials are described in this review.

  15. Poly(ethylene glycol)-functionalized polymeric microchips for capillary electrophoresis.

    Science.gov (United States)

    Sun, Xuefei; Li, Dan; Lee, Milton L

    2009-08-01

    Recently, we reported the synthesis, fabrication, and preliminary evaluation of poly(ethylene glycol) (PEG)-functionalized polymeric microchips that are inherently resistant to protein adsorption without surface modification in capillary electrophoresis (CE). In this study, we investigated the impact of cross-linker purity and addition of methyl methacrylate (MMA) as a comonomer on CE performance. Impure poly(ethylene glycol) diacrylate (PEGDA) induced electroosmotic flow (EOF) and increased the separation time, while the addition of MMA decreased the separation efficiency to approximately 25% of that obtained using microchips fabricated without MMA. Resultant improved microchips were evaluated for the separation of fluorescent dyes, amino acids, peptides, and proteins. A CE efficiency of 4.2 x 10(4) plates for aspartic acid in a 3.5 cm long microchannel was obtained. Chiral separation of 10 different D,L-amino acid pairs was obtained with addition of a chiral selector (i.e., beta-cyclodextrin) in the running buffer. Selectivity (alpha) and resolution (R(s)) for D,L-leucine were 1.16 and 1.64, respectively. Good reproducibility was an added advantage of these PEG-functionalized microchips.

  16. Characterization and solubility study of norfloxacin-polyethylene glycol, polyvinylpyrrolidone and carbopol 974p solid dispersions.

    Science.gov (United States)

    Gorajana, Adinarayana; Kit, Wong W; Dua, Kamal

    2015-01-01

    Norfloxacin has a low aqueous solubility which leads to poor dissolution. Keeping this fact in mind the purpose of the present study is to formulate and evaluate norfloxacin solid dispersion. Solid dispersions were prepared using hydrophilic carriers like polyethylene glycol (PEG) 4000, polyvinylpyrrolidone (PVP) k30 and carbopol 974pNF (CP) in various ratios using solvent evaporation technique. These formulations were evaluated using solubility studies, dissolution studies; Fourier transmitted infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetery (DSC). The influence of polymer type and drug to polymer ratio on the solubility and dissolution rate of norfloxacin was also evaluated. FTIR analysis showed no interaction of all three polymers with norfloxacin. The results from XRD and DSC analyses of the solid dispersion preparations showed that norfloxacin existsin its amorphous form. Among the Norfloxacin: PEG solid dispersions, Norfloxacin: PEG 1:14 ratio showed the highest dissolution rate at pH 6.8. For norfloxacin: PVP solid dispersions, norfloxacin: PVP 1:10 ratio showed the highest dissolution rate at pH 6.8. For Norfloxacin: CP solid dispersions, norfloxacin: P 1:2 ratio showed the highest dissolution rate at pH 6.8. The solid dispersion of norfloxacin with polyethylene glycol (PEG) 4000, polyvinylpyrrolidone (PVP) k30 and carbopol 974p NF (CP), lends an ample credence for better therapeutic efficacy.

  17. Semi-interpenetrating polymer networks of chitosan and poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Milosavljević Nedeljko B.

    2008-01-01

    Full Text Available Chitosan is a natural polycationic polymer that possesses useful properties such as bioactivity, biocompatibility, non-toxicity and non-antigenicity. On the other hand, its mechanical properties are not good for some biomedical application. They may be improved by preparing semi-interpenetrating polymer networks (semi-IPNs, when the hydrogel network is prepared in the presence of a previously made polymer such as poly(ethylene glycol. This paper deals with synthesis and characterization of the semi-interpenetrating polymer networks of chitosan and poly(ethylene glycol with different Ch/PEG ratio and crosslinking degree. The degree of deacetylation of chitosan was determined by potentiometric titration, titration and elemental analysis. The semi-IPNs were characterized by swelling kinetics, mechanical properties and thermal analysis. It was found that PEG content and crosslinking agent concentration significantly influence the swelling behaviour of semi-IPNs. Water uptake was higher for lower crosslinking agent concentrations and PEG contents, up to PEG/Ch = 0,75. Better mechanical strength of semi-IPNs was obtained for higher PEG content and crosslinking agent concentration. SEM analysis confirmed the porous structure of semi-IPNs. Increasing the degree of crosslinking and PEG content up to PEG/Ch = 0,75, the pore size decreased. Based on the pore size, the investigated semi-IPNs can be regarded as macroporous. Thermogravimetric analysis showed that thermal stability of the semi-IPNs depends on the degree of crosslinking, as well as on the PEG content.

  18. Intermolecular interactions at early stage of protein/detergent particle association induced by salt/polyethylene glycol mixtures.

    Science.gov (United States)

    Odahara, Takayuki; Odahara, Koji

    2016-04-01

    Mixtures of neutral salts and polyethylene glycol are used for various purposes in biological studies. Although the effects of each component of the mixtures are theoretically well investigated, comprehension of their integrated effects remains insufficient. In this work, their roles and effects as a precipitant were clarified by studying dependence of precipitation curves on salt concentration for integral membrane protein/detergent particles of different physicochemical properties. The dependence of precipitation curves was reasonably related to intermolecular interactions among relevant molecules such as protein, detergent and polyethylene glycol by considering their physicochemical properties. The obtained relationships are useful as basic information to learn the early stage of biological macromolecular associations.

  19. Interrelationship between partition behavior of organic compounds and proteins in aqueous dextran-polyethylene glycol and polyethylene glycol-sodium sulfate two-phase systems.

    Science.gov (United States)

    Ferreira, Luisa A; da Silva, Nuno R; Wlodarczyk, Samarina R; Loureiro, Joana A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2016-04-22

    Partition behavior of adenosine and guanine mononucleotides was examined in aqueous dextran-polyethylene glycol (PEG) and PEG-sodium sulfate two-phase systems. The partition coefficients for each series of mononucleotides were analyzed as a functions of the number of phosphate groups and found to be dependent on the nature of nucleic base and on the type of ATPS utilized. It was concluded that an average contribution of a phosphate group into logarithm of partition coefficient of a mononucleotide cannot be used to estimate the difference between the electrostatic properties of the coexisting phases of ATPS. The data obtained in this study were considered together with those for other organic compounds and proteins reported previously, and the linear interrelationship between logarithms of partition coefficients in dextran-PEG, PEG-Na2SO4 and PEG-Na2SO4-0.215M NaCl (all in 0.01M Na- or K/Na-phosphate buffer, pH 7.4 or 6.8) was established. Similar relationship was found for the previously reported data for proteins in Dex-PEG, PEG-600-Na2SO4, and PEG-8000-Na2SO4 ATPS. It is suggested that the linear relationships of the kind established in ATPS may be observed for biological properties of compounds as well.

  20. Influence of polyethylene glycol chain length on compatibility and release characteristics of ternary solid dispersions of itraconazole in polyethylene glycol/hydroxypropylmethylcellulose 2910 E5 blends.

    Science.gov (United States)

    Janssens, Sandrien; Denivelle, Samgar; Rombaut, Patrick; Van den Mooter, Guy

    2008-10-02

    The present study aims to elucidate the influence of the polyethylene glycol chain length on the miscibility of PEG/HPMC 2910 E5 polymer blends, the influence of polymer compatibility on the degree of molecular dispersion of itraconazole, and in vitro dissolution. PEG 2000, 6000, 10,000 and 20,000 were included in the study. Solid dispersions were prepared by spray drying and characterized with MDSC, XRPD and in vitro dissolution testing. The polymer miscibility increased with decreasing chain length due to a decrease in the Gibbs free energy of mixing. Recrystallization of itraconazole occurred as soon as a critical temperature of ca. 75 degrees C was reached for the glass transition that represents the ternary amorphous phase. Due to the lower miscibility degree between the longer PEG types and HPMC 2910 E5, the ternary amorphous phase was further separated, leading to a more rapid decrease of the ternary amorphous phase glass transition as a function of PEG and itraconazole weight percentage and hence, itraconazole recrystallization. In terms of release, an advantage of the shorter chain length PEG types (2000, 6000) over the longer chain length PEG types (10,000, 20,000) was observed for the polymer blends with 5% of PEG with respect to the binary itraconazole/HPMC 2910 E5 solid dispersion. Among the formulations with a 15/85 (w/w) PEG/HPMC 2910 E5 ratio on the other hand, there was no difference in the release profile.

  1. Effect of Polyethylene Glycol on Properties and Drug Encapsulation-Release Performance of Biodegradable/Cytocompatible Agarose-Polyethylene Glycol-Polycaprolactone Amphiphilic Co-Network Gels.

    Science.gov (United States)

    Chandel, Arvind K Singh; Kumar, Chinta Uday; Jewrajka, Suresh K

    2016-02-10

    We synthesized agarose-polycaprolactone (Agr-PCL) bicomponent and Agr-polyethylene glycol-PCL (Agr-PEG-PCL) tricomponent amphiphilic co-network (APCN) gels by the sequential nucleophilic substitution reaction between amine-functionalized Agr and activated halide terminated PCL or PCL-b-PEG-b-PCL copolymer for the sustained and localized delivery of hydrophilic and hydrophobic drugs. The biodegradability of the APCNs was confirmed using lipase and by hydrolytic degradation. These APCN gels displayed good cytocompatibility and blood compatibility. Importantly, these APCN gels exhibited remarkably high drug loading capacity coupled with sustained and triggered release of both hydrophilic and hydrophobic drugs. PEG in the APCNs lowered the degree of phase separation and enhanced the mechanical property of the APCN gels. The drug loading capacity and the release kinetics were also strongly influenced by the presence of PEG, the nature of release medium, and the nature of the drug. Particularly, PEG in the APCN gels significantly enhanced the 5-fluorouracil loading capacity and lowered its release rate and burst release. Release kinetics of highly water-soluble gemcitabine hydrochloride and hydrophobic prednisolone acetate depended on the extent of water swelling of the APCN gels. Cytocompatibility/blood compatibility and pH and enzyme-triggered degradation together with sustained release of drugs show great promise for the use of these APCN gels in localized drug delivery and tissue engineering applications.

  2. Universal concept for the implementation of a single cleavable unit at tunable position in functional poly(ethylene glycol)s.

    Science.gov (United States)

    Dingels, Carsten; Müller, Sophie S; Steinbach, Tobias; Tonhauser, Christine; Frey, Holger

    2013-02-11

    Poly(ethylene glycol) (PEG) with acid-sensitive moieties gained attention particularly for various biomedical applications, such as the covalent attachment of PEG (PEGylation) to protein therapeutics, the synthesis of stealth liposomes, and polymeric carriers for low-molecular-weight drugs. Cleavable PEGs are favored over their inert analogues because of superior pharmacodynamic and/or pharmacokinetic properties of their formulations. However, synthetic routes to acetal-containing PEGs published up to date either require enormous efforts or result in ill-defined materials with a lack of control over the molecular weight. Herein, we describe a novel methodology to implement a single acetaldehyde acetal in well-defined (hetero)functional poly(ethylene glycol)s with total control over its position. To underline its general applicability, a diverse set of initiators for the anionic polymerization of ethylene oxide (cholesterol, dibenzylamino ethanol, and poly(ethylene glycol) monomethyl ether (mPEG)) was modified and used to synthesize the analogous labile PEGs. The polyether bearing the cleavable lipid had a degree of polymerization of 46, was amphiphilic and exhibited a critical micelle concentration of 4.20 mg·L(-1). From dibenzylamino ethanol, three heterofunctional PEGs with different molecular weights and labile amino termini were generated. The transformation of the amino functionality into the corresponding squaric acid ester amide demonstrated the accessibility of the cleavable functional group and activated the PEG for protein PEGylation, which was exemplarily shown by the attachment to bovine serum albumin (BSA). Furthermore, turning mPEG into a macroinitiator with a cleavable hydroxyl group granted access to a well-defined poly(ethylene glycol) derivative bearing a single cleavable moiety within its backbone. All the acetal-containing PEGs and PEG/protein conjugates were proven to degrade upon acidic treatment.

  3. Methoxy polyethylene glycol-epoetin beta for anemia with chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Ohashi N

    2012-03-01

    Full Text Available Naro Ohashi1, Yukitoshi Sakao2, Hideo Yasuda1, Akihiko Kato2, Yoshihide Fujigaki11Internal Medicine 1, 2Blood Purification Unit, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, JapanAbstract: Chronic kidney disease (CKD is a risk factor for end-stage renal failure and cardiovascular events. In patients with CKD, anemia is often caused by decreased erythropoietin production relative to hemoglobin levels. As correction of anemia is associated with improved cardiac and renal function and quality of life, erythropoiesis-stimulating agents (ESAs are standard therapy for anemia in CKD patients. However, traditional ESAs such as epoetin or darbepoetin have short half-lives and require frequent administration, dose changes, and close monitoring of hemoglobin concentration to maintain target hemoglobin levels. Methoxy polyethylene glycol-epoetin beta (MPG-EPO is the only ESA that is generated by chemical modification of glycosylated erythropoietin through the integration of one specific, long, linear chain of polyethylene glycol. This ESA induces continuous erythropoietin receptor activation and has a long half-life (approximately 130 hours. Subcutaneous or intravenous administration of MPG-EPO once every 2 weeks or monthly achieved a high hemoglobin response rate in patients with anemia associated with CKD, regardless of whether the patient was undergoing dialysis. According to data from an observational time and motion study, MPG-EPO maintains hemoglobin levels when the same dose is administered, however infrequently. This suggests that compared with the use of traditional ESAs, administration of MPG-EPO reduces the overall time and cost associated with the management of anemia in CKD patients undergoing dialysis. MPG-EPO is generally well tolerated and most adverse events are of mild to moderate severity. The most commonly reported adverse effects are hypertension, nasopharyngitis, and diarrhea. Subcutaneous injection of MPG-EPO is

  4. Release of anti-restenosis drugs from poly(ethylene oxide)-poly (DL-lactic-co-glycolic acid) nanoparticles

    NARCIS (Netherlands)

    Zweers, Miechel L. T.; Engbers, Gerard H. M.; Grijpma, Dirk W.; Feijen, Jan

    2006-01-01

    Dexamethasone- or rapamycin-loaded nanoparticles based on poly(ethylene oxide) and poly(DL-lactic-co-glycolic acid) block copolymers (PEO-PLGA) were prepared without additional stabilizer using the salting-out method. A fast release of drug in PBS (PH 7.4) at 37 degrees C resulting in 100% release w

  5. Physicochemical and biological evaluation of poly(ethylene glycol) methacrylate grafted onto poly(dimethyl siloxane) surfaces for prosthetic devices

    NARCIS (Netherlands)

    Goncalves, Sara; Leiros, Ana; Van Kooten, Theo; Dourado, Fernando; Rodrigues, Ligia R.

    2013-01-01

    Poly(dimethyl siloxane) (PDMS) was surface-polymerized with poly(ethylene glycol)methacrylate (PEGMA) by surface-initiated atom transfer radical polymerization (SI-ATRP) in aqueous media at room temperature. Modification of the PDMS surface followed a three-step procedure: (i) PDMS surface hydroxyla

  6. Physicochemical and biological evaluation of poly(ethylene glycol) methacrylate grafted onto poly(dimethyl siloxane) surfaces for prosthetic devices

    NARCIS (Netherlands)

    Goncalves, Sara; Leiros, Ana; Van Kooten, Theo; Dourado, Fernando; Rodrigues, Ligia R.

    2013-01-01

    Poly(dimethyl siloxane) (PDMS) was surface-polymerized with poly(ethylene glycol)methacrylate (PEGMA) by surface-initiated atom transfer radical polymerization (SI-ATRP) in aqueous media at room temperature. Modification of the PDMS surface followed a three-step procedure: (i) PDMS surface

  7. Surface morphology of polyethylene glycol films produced by matrix-assisted pulsed laser evaporation (MAPLE): Dependence on substrate temperature

    DEFF Research Database (Denmark)

    Rodrigo, K.; Czuba, P.; Toftmann, B.;

    2006-01-01

    The dependence of the surface morphology on the substrate temperature during film deposition was investigated for polyethylene glycol (PEG) films by matrix-assisted pulsed laser evaporation (MAPLE). The surface structure was studied with a combined technique of optical imaging and AFM measurements...

  8. Determination of the enantiomeric purity of (-) terbutaline by capillary electrophoresis using cyclodextrins as chiral selectors in a polyethylene glycol gel

    NARCIS (Netherlands)

    de Boer, Theo; Ensing, K

    1998-01-01

    A method was developed for determination of the enantiomeric purity of the therapeutic-pharmacological active (-)-enantiomer of terbutaline using cyclodextrins as a chiral selector dissolved in a removable liquid polyethylene glycol gel by use of capillary electrophoresis. The effect of temperature,

  9. Comparison of the migration behavior of nanoparticles based on polyethylene glycol and silica using micellar electrokinetic chromatography.

    Science.gov (United States)

    Kato, Masaru; Sasaki, Minoru; Ueyama, Yukari; Koga, Ayaka; Sano, Akira; Higashi, Tatsuya; Santa, Tomofumi

    2015-02-01

    Nanoparticles, spherical particles with diameters less than 100 nm, are promising theranostic devices for noninvasive diagnosis and therapy. In this study, nanoparticles composed of polyethylene glycol and silica were prepared, and their migration behavior was examined using capillary electrophoresis. The effects of the sodium dodecyl sulfate concentration in the electrolyte, the nanoparticle size, and the encapsulated molecule on the migration were examined. The addition of sodium dodecyl sulfate into the electrolyte had a significant effect on the electrophoretic mobility of polyethylene glycol nanoparticles, but a small effect on that of silica nanoparticles. As for the size effect, the mobility became a little faster for smaller nanoparticle sizes for both polyethylene glycol and silica nanoparticles. The encapsulated molecule affected the mobility of the nanoparticles through interactions between the encapsulated molecules and sodium dodecyl sulfate. We propose that the large effect of sodium dodecyl sulfate on the migration of the polyethylene glycol nanoparticles was due to the large spaces within the nanoparticles. These results indicate that nanoparticle migration is mainly determined by the nanoparticle components.

  10. High fluence deposition of polyethylene glycol films at 1064 nm by matrix assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Purice, Andreea; Schou, Jørgen; Kingshott, P.;

    2007-01-01

    Matrix assisted pulsed laser evaporation (MAPLE) has been applied for deposition of thin polyethylene glycol (PEG) films with infrared laser light at 1064 nm. We have irradiated frozen targets (of 1 wt.% PEG dissolved in water) and measured the deposition rate in situ with a quartz crystal 2...

  11. Protein and cell patterning in closed polymer channels by photoimmobilizing proteins on photografted poly(ethylene glycol) diacrylate

    DEFF Research Database (Denmark)

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

    2014-01-01

    present a one-step photochemical process to coat the inner surfaces of closed microfluidic channels with a nanometer thick layer of poly(ethylene glycol) (PEG), well known to strongly reduce non-specific adsorption, using only commercially available reagents in an aqueous environment. The coating consists...

  12. Characterisation of the Polyethylene Glycol Impregnation of the Swedish Warship Vasa and one of the Danish Skuldelev Viking Ships

    DEFF Research Database (Denmark)

    Mortensen, M.N.; Egsgaard, Helge; Hvilsted, Søren;

    2007-01-01

    The Swedish l7th century warship Vasa and the Danish Skuldelev Viking ships from the 1 lth century were impregnated with polyethylene glycol (PEG) in the 1960s. The molecular weight, amount and integrity of this PEG were investigated at a range of depths below the wood surface. Large amounts of PEG...

  13. Release of anti-restenosis drugs from poly(ethylene oxide)-poly (DL-lactic-co-glycolic acid) nanoparticles

    NARCIS (Netherlands)

    Zweers, M.L.T.; Engbers, G.H.M.; Grijpma, Dirk W.; Feijen, Jan

    2007-01-01

    Dexamethasone- or rapamycin-loaded nanoparticles based on poly(ethylene oxide) and poly(dl-lactic-co-glycolic acid) block copolymers (PEO-PLGA) were prepared without additional stabilizer using the salting-out method. A fast release of drug in PBS (pH 7.4) at 37 °C resulting in 100% release within 5

  14. Designed biodegradable hydrogel structures prepared by stereolithography using poly(ethylene glycol)/poly(D,L-lactide)-based resins

    NARCIS (Netherlands)

    Seck, Tetsu M.; Melchels, Ferry P. W.; Feijen, Jan; Grijpma, Dirk W.

    2010-01-01

    Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibi

  15. Gene transcription and steviol glycoside accumulation in Stevia rebaudiana under polyethylene glycol-induced drought stress in greenhouse cultivation.

    Science.gov (United States)

    Hajihashemi, Shokoofeh; Geuns, Jan M C

    2016-09-01

    Stevia rebaudiana is a sweet herb of the Astraceae family, which is cultivated for the natural sweeteners it contains. The aim of this study was to assess the effect of drought, simulated by the application of polyethylene glycol (5%, 10%, and 15% w/v), on the content of steviol glycosides (SVglys) and transcription levels of six genes involved in the biosynthesis of these natural sweeteners. The transcription levels of ent-kaurene synthase, ent-kaurene oxidase, ent-kaurenoic acid hydroxylase, and three UDP-dependent glycosyltransferases, UGT85C2,UGT74G1 and UGT76G1 were downregulated under polyethylene glycol treatment. Polyethylene glycol treatment significantly decreased the amount of stevioside, rebaudioside A, B, C and F, steviolbioside, dulcoside A, rubusoside, and total SVglys. These results strongly suggest a close relationship of SVglys content with the transcription of genes involved in the SVglys biosynthesis pathway. Comparing the observations of the present study with other reports provided the knowledge that the Stevia response to drought stress can be influenced by different environmental and experimental factors, in addition to intensity of drought stress. In conclusion, these results strongly suggest that polyethylene glycol-induced drought stress has a negative effect on the content of SVglys and transcription of SVglys biosynthetic genes and that this should be investigated further. We recommend that sufficient irrigation of Stevia is required to obtain a high content of SVglys.

  16. Release of anti-restenosis drugs from poly(ethylene oxide)-poly(dl-lactic-co-glycolic acid) nanoparticles

    NARCIS (Netherlands)

    Zweers, Miechel L.T.; Engbers, Gerard H.M.; Grijpma, Dirk W.; Feijen, Jan

    2006-01-01

    Dexamethasone- or rapamycin-loaded nanoparticles based on poly(ethylene oxide) and poly(dl-lactic-co-glycolic acid) block copolymers (PEO-PLGA) were prepared without additional stabilizer using the salting-out method. A fast release of drug in PBS (pH 7.4) at 37 °C resulting in 100% release within 5

  17. Synthesis of Aluminium Nanoparticles in A Water/Polyethylene Glycol Mixed Solvent using μ-EDM

    Science.gov (United States)

    Sahu, R. K.; Hiremath, Somashekhar S.

    2017-08-01

    Nanoparticles present a practical way of retaining the results of the property at the atomic or molecular level. Due to the recent use of nanoparticles in scientific, industrial and medical applications, synthesis of nanoparticles and their characterization have become considerably important. Currently, aluminium nanoparticles have attracted significant research attention because of their reasonable cost, unique properties and interdisciplinary emerging applications. The present paper reports the synthesis of aluminium nanoparticles in the mixture of Deionized water (DI water) and Polyethylene Glycol (PEG) using a developed micro-Electrical Discharge Machining (μ-EDM) method. PEG was used as a stabilizer to prevent nanoparticles from agglomeration produced during the μ -EDM process. The synthesized aluminium nanoparticles were examined by Transmission Electron Microscopy (TEM), Energy Dispersive Analysis by X-rays (EDAX) and Selected Area Electron Diffraction (SAED) pattern to determine their size, shape, chemical nature and crystal structure. The average size of the polyhedral aluminium nanoparticles is found to be 196 nm.

  18. Kinetics of the esterification of active pharmaceutical ingredients containing carboxylic Acid functionality in polyethylene glycol

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie V; Hansen, Steen Honoré; Moesgaard, Birthe;

    2014-01-01

    Polyethylene glycols (PEGs) are attractive as excipients in the manufacture of drug products because they are water soluble and poorly immunogenic. They are used in various pharmaceutical preparations. However, because of their terminal hydroxyl groups, PEGs can participate in esterification...... reactions. In this study, kinetics of two active pharmaceutical ingredients, cetirizine and indomethacin possessing carboxylic acid functionality, has been studied in PEG 400 and PEG 1000 at 50°C, 60°C, 70°C, and 80°C. HPLC-UV was applied for the determination of concentrations in the kinetic studies......, it is important to be aware of this drug-excipient interaction, as it can reduce the shelf-life of a low-average molecular weight PEG formulation considerably. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2424-2433, 2014....

  19. 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.

  20. Insertion Testing of Polyethylene Glycol Microneedle Array into Cultured Human Skin with Biaxial Tension

    Science.gov (United States)

    Takano, Naoki; Tachikawa, Hiroto; Miyano, Takaya; Nishiyabu, Kazuaki

    Aiming at the practical use of polyethylene glycol (PEG) microneedles for transdermal drug delivery system (DDS), a testing apparatus for their insertion into cultured human skin has been developed. To simulate the variety of conditions of human skin, biaxial tension can be applied to the cultured human skin. An adopted testing scheme to apply and control the biaxial tension is similar to the deep-draw forming technique. An attention was also paid to the short-time setup of small, thin and wet cultured skin. One dimensional array with four needles was inserted and influence of tension was discussed. It was found that tension, deflection of skin during insertion and original curvature of skin are the important parameters for microneedles array design.

  1. Synthesis and MALDI-ToF characterization of dendronized poly(ethylene glycols

    Directory of Open Access Journals (Sweden)

    Brittany K. Myers

    2013-01-01

    Full Text Available Well-defined hybrids of linear poly(ethylene glycols (PEGs and dendritic polyesters were prepared via the dendronization of the alcohol end groups of the mono and difunctional linear PEGs. Though useful for rudimentary product characterization, GPC and NMR could not verify the overall structural purity of these linear-dendritic hybrids. On the other hand, the detailed data provided by MALDI-ToF mass spectrometry enabled confirmation of the high structural purity of the dendronized PEGs at each step of the dendronization procedure. The well-defined number of functionalities on these dendronized PEGs, renders them particularly useful for research in the biomedical sphere where functionality and purity are of the utmost importance. The MALDI-ToF mass spectrometric approach described herein represents a valuable technique for detailed monitoring of these dendronization reactions, as well as a variety of other polymer end group modifications.

  2. Fabrication of anti-protein-fouling poly(ethylene glycol) microfluidic chip electrophoresis by sandwich photolithography.

    Science.gov (United States)

    Cong, Hailin; Xu, Xiaodan; Yu, Bing; Liu, Huwei; Yuan, Hua

    2016-07-01

    Microfluidic chip electrophoresis (MCE) is a powerful separation tool for biomacromolecule analysis. However, adsorption of biomacromolecules, particularly proteins onto microfluidic channels severely degrades the separation performance of MCE. In this paper, an anti-protein-fouling MCE was fabricated using a novel sandwich photolithography of poly(ethylene glycol) (PEG) prepolymers. Photopatterned microchannel with a minimum resolution of 10 μm was achieved. After equipped with a conventional online electrochemical detector, the device enabled baseline separation of bovine serum albumin, lysozyme (Lys), and cytochrome c (Cyt-c) in 53 s under a voltage of 200 V. Compared with a traditional polydimethylsiloxane MCE made by soft lithography, the PEG MCE made by the sandwich photolithography not only eliminated the need of a master mold and the additional modification process of the microchannel but also showed excellent anti-protein-fouling properties for protein separation.

  3. Influence of polyethylene glycol on the ligation reaction with calf thymus DNA ligases I and II.

    Science.gov (United States)

    Teraoka, H; Tsukada, K

    1987-01-01

    High concentrations of the nonspecific macromolecule polyethylene glycol 6000 (PEG 6000) enabled DNA ligases I and II from calf thymus to catalyze intermolecular blunt-end ligation of duplex DNA. Intermolecular cohesive-end ligation with these enzymes was markedly stimulated in the presence of 10-16% (w/v) PEG 6000. The effect of PEG 6000 (4-16%) on the sealing of single-stranded breaks in duplex DNA with DNA ligases I and II was not appreciably stimulatory but rather inhibitory. PEG 6000 (15%) enhanced more twofold the rate of DNA ligase II-AMP complex formation, but moderately suppressed the rate of formation of DNA ligase 1-AMP complex. Polyamines and KCl inhibited blunt-end and cohesive-end ligations with DNA ligases I and II in the presence of PEG 6000.

  4. Methoxy polyethylene glycol-epoetin beta for the treatment of anemia associated with chronic renal failure.

    Science.gov (United States)

    Schmid, Holger

    2016-01-01

    Since more than two decades erythropoiesis-stimulating agents are the main pillar for treatment of anemia associated with chronic kidney disease. Methoxy polyethylene glycol-epoetin beta (MPG-EPO), also called continuous erythropoietin receptor activator, is the longest acting erythropoiesis-stimulating agent currently available. MPG-EPO is characterized by an elimination half-life of approximately 137 h and offers extended dosing intervals up to 4 weeks. Numerous phase I/II studies and a comprehensive clinical phase III program demonstrated the feasibility of MPG-EPO therapy for anemia correction and maintenance of stable hemoglobin levels in adult chronic kidney disease patients. Due to patent disputes MPG-EPO was only available outside the US market so far. In view of a prevailing US market introduction, this review focuses on efficacy and safety data from pivotal trials, summarizes recent clinical research and finally tries to substantiate potential benefits associated with the use of this anti-anemic drug.

  5. Preparation and characterization of polyethylene glycol diacrylate microgels using electron beam radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hamzah, Mohd Yusof [Makmal Nanoteknologi, Bahagian Teknologi Sinaran (Malaysia); Isa, Naurah Mat; Napia, Liyana M. Ali [ALURTRON, Bahagian Kemudahan Iradiasi, Malaysian Nuclear Agency, 43000, Kajang, Selangor (Malaysia)

    2014-02-12

    The use of microemulsion in the development of nanosized gels based on polyethylene glycol diacrylate (PEGDA) is demonstrated. PEGDA was solubilized in n-heptane with use of sodium docusate (AOT) at 0.15M concentration to form reverse micelles. These micelles were than irradiated at 5, 10, 15, 20 and 25 kGy using electron beam (EB) to crosslink the entrapped polymer in the micelles. Ionizing radiation was imparted to the emulsions to generate crosslinking reaction in the micelles formed. The nanosized gels were evaluated in terms of particle diameter using dynamic light scattering (DLS) and the images of the nanosized gels were studied using transmission electron microscopy (TEM). Results show that the size and shape of the particles are influenced by concentration of PEGDA and radiation dose. This study showed that this method can be utilized to produce nanosized gels.

  6. Enhanced photocatalytic activity of TiO2 films by modification with polyethylene glycol

    Directory of Open Access Journals (Sweden)

    Álvaro A. Ramírez-Santos

    2012-01-01

    Full Text Available Titanium dioxide porous thin films on the Anatase phase were deposited onto glass slides by the sol-gel method assisted with polyethylene glycol (PEG. The dip-coated films were characterized using scanning electron microscopy (SEM, thermogravimetric analysis (TGA and DTG, UV-visible spectroscopy and X-ray diffraction (XRD. The photocatalytic activity of the films was determined by means of methyl-orange oxidation tests. The resultant PEG-modified films were crack-free and developed a porous structure after calcination at 500 °C. Photo-oxidation tests showed the dependency of catalytic activity of the films on the number of layers (thickness and porosity, i.e. of the interfacial area.

  7. Synthesis of single crystalline CdS nanowires with polyethylene glycol 400 as inducing template

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Solvothermal technique, an one-step soft solution-processing route was successfully employed to synthesize single crystalline CdS nanowires in ethylenediamine medium at lower temperature (170 □) for 1-8 d. In this route, polyethylene glycol 400 (PEG400)was used as surfactant, which played a crucial role in preferentially oriented growth of semiconductor nanowires. Characterizations of as-prepared CdS nanowires by X-ray powder diffraction(XRD), transmission electron microscopy(TEM) indicate that the naonowires,with typical diameters of 20nm and lengths up to several micrometers, have preferential [001] orientation. Also, investigations into the physical properties of the CdS nanowires were conducted with UV-Vis absorption spectroscopy and photoluminescence emission spectroscopy. The excitonic photo-optical phenomena of the nanowires shows the potential in the practical applications.

  8. 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.

  9. Oligonucleotides conjugated with short chemically defined polyethylene glycol chains are efficient antisense agents.

    Science.gov (United States)

    Shokrzadeh, Nasrin; Winkler, Anna-Maria; Dirin, Mehrdad; Winkler, Johannes

    2014-12-15

    Ligand conjugation is an attractive approach to rationally modify the poor pharmacokinetic behavior and cellular uptake properties of antisense oligonucleotides. Polyethylene glycol (PEG) attachment is a method to increase solubility of oligonucleotides and prevent the rapid elimination, thus increasing tissue distribution. On the other hand, the attachment of long PEG chains negatively influences the pharmacodynamic effect by reducing the hybridization efficiency. We examined the use of short PEG ligands on the in vitro effect of antisense agents. Circular dichroism showed that the tethering of PEG12-chains to phosphodiester and phosphorothioate oligonucleotides had no influence on their secondary structure and did not reduce the affinity to the counter strand. In an in vitro tumor model, a luciferase reporter assay indicated unchanged gene silencing activity compared to unmodified compounds, and even slightly superior target down regulation was found after treatment with a phosphorothioate modified conjugate. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Synthesis and Characterization of Polyethylene Glycol Mediated Silver Nanoparticles by the Green Method

    Directory of Open Access Journals (Sweden)

    Yadollah Abdollahi

    2012-05-01

    Full Text Available The roles of green chemistry in nanotechnology and nanoscience fields are very significant in the synthesis of diverse nanomaterials. Herein, we report a green chemistry method for synthesized colloidal silver nanoparticles (Ag NPs in polymeric media. The colloidal Ag NPs were synthesized in an aqueous solution using silver nitrate, polyethylene glycol (PEG, and β-d-glucose as a silver precursor, stabilizer, and reducing agent, respectively. The properties of synthesized colloidal Ag NPs were studied at different reaction times. The ultraviolet-visible spectra were in excellent agreement with the obtained nanostructure studies performed by transmission electron microscopy (TEM and their size distributions. The Ag NPs were characterized by utilizing X-ray diffraction (XRD, zeta potential measurements and Fourier transform infrared (FT-IR. The use of green chemistry reagents, such as glucose, provides green and economic features to this work.

  11. Preparation and characterization of polyethylene glycol diacrylate microgels using electron beam radiation

    Science.gov (United States)

    Hamzah, Mohd Yusof; Isa, Naurah Mat; Napia, Liyana M. Ali

    2014-02-01

    The use of microemulsion in the development of nanosized gels based on polyethylene glycol diacrylate (PEGDA) is demonstrated. PEGDA was solubilized in n-heptane with use of sodium docusate (AOT) at 0.15M concentration to form reverse micelles. These micelles were than irradiated at 5, 10, 15, 20 and 25 kGy using electron beam (EB) to crosslink the entrapped polymer in the micelles. Ionizing radiation was imparted to the emulsions to generate crosslinking reaction in the micelles formed. The nanosized gels were evaluated in terms of particle diameter using dynamic light scattering (DLS) and the images of the nanosized gels were studied using transmission electron microscopy (TEM). Results show that the size and shape of the particles are influenced by concentration of PEGDA and radiation dose. This study showed that this method can be utilized to produce nanosized gels.

  12. Efficiency and biocompatibility of a polyethylene glycol grafted cellulosic membrane during hemodialysis.

    Science.gov (United States)

    Akizawa, T; Kino, K; Koshikawa, S; Ikada, Y; Kishida, A; Yamashita, M; Imamura, K

    1989-01-01

    Dialytic efficiency and biocompatibility of a new modified cellulose membrane (NMC) were examined in vitro and clinically. NMC was obtained by grafting polyethylene-glycol (PEG) chains to the membrane surface of ordinary cellulose (OC), and it was expected that the random movement of PEG chains would prevent blood cells and large plasma proteins from coming into contact with the membrane surface, resulting in improving the biocompatibility and thrombogenicity of the membrane. Surface characteristics of NMC were rendered anionic and hydrophilic, however, the activations of complement and platelet systems were clearly suppressed in NMC. Minimum heparin requirement for hemodialysis was significantly lower with NMC than with OC dialyzer. No significant difference in solute and water removal was observed between the two dialyzers. These results indicate that NMC can provide increased biocompatibility and antithrombogenic effect while retaining the essential dialysis efficiency of OC.

  13. Clinical effects of a polyethylene glycol grafted cellulose membrane on thrombogenicity and biocompatibility during hemodialysis.

    Science.gov (United States)

    Akizawa, T; Kino, K; Kinugasa, E; Koshikawa, S; Ikada, Y; Kishida, A; Hatanaka, Y; Imamura, K

    1990-01-01

    The biocompatibility and thrombogenicity of polyethylene-glycol (PEG)-grafted cellulose hemodialysis (HD) membranes (PEGC) were investigated in cross-over HD of five HD patients with ordinary cellulose (OC). The PEGC significantly suppressed transient leukocyte and thrombocytopenia, and release of C3a, beta-thromboglobulin and platelet factor 4, in corresponding with the quantity of grafted PEG. HD with PEGC resulted in lower granulocyte elastase production, protein and blood cells adsorption on the membrane surface than those with OC. Minimum heparin in HD with PEGC was three times lower than that with OC, with the thrombin-antithrombin III complex elevation lower than that in HD with OC. The results indicate that the grafted PEG effectively suppresses blood and membrane interaction, thus improving biocompatibility and reducing thrombogenicity in clinical HD.

  14. Polyethylene glycol-grafted poly-L-lysine as polymeric gene carrier.

    Science.gov (United States)

    Choi, Y H; Liu, F; Kim, J S; Choi, Y K; Park, J S; Kim, S W

    1998-06-01

    A new series of gene carriers, polyethylene glycol (PEG)-grafted poly-L-lysine (PLL, mol. wt. = 25000) with three different PEG-grafted ratios (5, 10 and 25 mole%, which means 5, 10 and 25% of epsilon-amino group of PLL was modified by PEG), was synthesized. These new gene carriers, named comb-shaped PEG-g-PLL copolymer, showed a 5- to 30-fold increase in transfection efficiency compared to PLL alone on a human carcinoma cell line. It is likely that Hep G2 cells were transfected by plasmid DNA/PEG-g-PLL complexes through an endocytosis mechanism due to the fact that chloroquine increased transfection efficiency. Although Lipofectin, a cationic lipid formulation, showed slightly higher transfection efficiency than PEG-g-PLL in Hep G2 cells, our designed PEG-g-PLL demonstrated lower cytotoxicity, early gene expression and maintenance of gene expression for up to 96 h.

  15. Anaphylactic reaction to polyethylene-glycol conjugated-asparaginase: premedication and desensitization may not be sufficient.

    Science.gov (United States)

    Sahiner, Umit M; Yavuz, S Tolga; Gökce, Muge; Buyuktiryaki, Betul; Altan, Ilhan; Aytac, Selin; Tuncer, Murat; Tuncer, Ayfer; Sackesen, Cansin

    2013-08-01

    In hypersensitive reactions to native L-asparaginase, either premedication and desensitization or substitution with polyethylene glycol conjugated asparaginase (PEG-ASP) is preferred. Anaphylaxis with PEG-ASP is rare. An 8-year-old girl and a 2.5-year-old boy, both diagnosed as having acute lymphoblastic leukemia, presented with native L-asparaginase hypersensitivity and substitution with PEG-ASP was preferred. They received a premedication (methylprednisolone, hydroxyzine and ranitidine) followed by desensitization with PEG-ASP infusion. Both patients developed anaphylaxis with peg-asparaginase. These are the first reported cases of anaphylactic reaction to PEG-ASP, despite the application of both premedication and desensitization. Anaphylaxis with PEG-ASP is very rare and premedication and desensitization protocols may not prevent these hypersensitive reactions. © 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.

  16. Analysis of polyethylene glycol (PEG) fusion in cultured neuroblastoma cells via flow cytometry: Techniques & optimization.

    Science.gov (United States)

    Hoffman, Ashley N; Bamba, Ravinder; Pollins, Alonda C; Thayer, Wesley P

    2017-02-01

    Polyethylene glycol (PEG) has long been used as a membrane fusogen, but recently it has been adopted as a technique for peripheral nerve repair. Vertebrate models using PEG fusion have shown improved outcomes when PEG is applied during repair of severed peripheral nerves. The cellular mechanism of PEG fusion in the peripheral nerve repair model has not previously been assessed via flow cytometry. PEG fusion was assessed in this experiment by dying B35 rat neuroblastoma cells with different color fluorescent labels. The different color cells were combined and PEG was applied in concentrations of 50%, 75% and 100%. The amount of cell fusion was assessed via flow cytometry as the percentage of double positive cells. Results showed increasing fusion and decreasing viability with increasing concentrations of PEG.

  17. Identification of polyethylene glycol-resistant macrophages on stealth imaging in vitro using fluorescent organosilica nanoparticles.

    Science.gov (United States)

    Nakamura, Michihiro; Hayashi, Koichiro; Nakano, Mutsuki; Kanadani, Takafumi; Miyamoto, Kazue; Kori, Toshinari; Horikawa, Kazuki

    2015-02-24

    An in vitro imaging system to evaluate the stealth function of nanoparticles against mouse macrophages was established using fluorescent organosilica nanoparticles. Surface-functionalized organosilica nanoparticles with polyethylene glycol (PEG) were prepared by a one-step process, resulting in a brush-type PEG layer. A simultaneous dual-particle administration approach enabled us to evaluate the stealth function of nanoparticles with respect to single cells using time-lapse fluorescent microscopic imaging and flow cytometry analyses. Single-cell imaging and analysis revealed various patterns and kinetics of bare and PEGylated nanoparticle uptake. The PEGylated nanoparticles revealed a stealth function against most macrophages (PEG-sensitive macrophages); however, a stealth function against certain macrophages (PEG-insensitive macrophages) was not observed. We identified and characterized the PEG-resistant macrophages that could take up PEGylated nanoparticles at the same level as bare nanoparticles.

  18. The effect of polyethylene glycol Mw 400 and 600 on stability of Shellac Waxfree

    Science.gov (United States)

    Khairuddin; Pramono, E.; Utomo, S. B.; Wulandari, V.; Zahrotul W, A.; Clegg, F.

    2016-11-01

    The effect of polyethylene glycol (PEG) having molecular weight of 400 and 600 on stability of shellac waxfree prepared by solvent-evaporation method was reported in the present paper. The stability of shellac was tested by life under heat at 125 °C for 10,30,90, and 180 minutes. It was found that that stability of shellac decreased with heating time at 125 °C. PEG400 gave the most stable effect of shellac for 30 minutes of heating, whereas at 90 minutes and above PEG600 gave the most effect of shellac stability as shown by insoluble solid test and FTIR. The WVTR showed that water vapour barrier properties of PEG600/shellac was beter than that of PEG400/shellac system.

  19. Rapid detection of polyethylene glycol sonolysis upon functionalization of carbon nanomaterials.

    Science.gov (United States)

    Murali, Vasanth S; Wang, Ruhung; Mikoryak, Carole A; Pantano, Paul; Draper, Rockford

    2015-09-01

    Polyethylene glycol (PEG) and related polymers are often used in the functionalization of carbon nanomaterials in procedures that involve sonication. However, PEG is very sensitive to sonolytic degradation and PEG degradation products can be toxic to mammalian cells. Thus, it is imperative to assess potential PEG degradation to ensure that the final material does not contain undocumented contaminants that can introduce artifacts into experimental results. Described here is a simple and inexpensive polyacrylamide gel electrophoresis method to detect the sonolytic degradation of PEG. The method was used to monitor the integrity of PEG phospholipid constructs and branched chain PEGs after different sonication times. This approach not only helps detect degraded PEG, but should also facilitate rapid screening of sonication parameters to find optimal conditions that minimize PEG damage.

  20. Optimizing the surface density of polyethylene glycol chains by grafting from binary solvent mixtures

    Science.gov (United States)

    Arcot, Lokanathan; Ogaki, Ryosuke; Zhang, Shuai; Meyer, Rikke L.; Kingshott, Peter

    2015-06-01

    Polyethylene glycol (PEG) brushes are very effective at controlling non-specific deposition of biological material onto surfaces, which is of paramount importance to obtaining successful outcomes in biomaterials, tissue engineered scaffolds, biosensors, filtration membranes and drug delivery devices. We report on a simple 'grafting to' approach involving binary solvent mixtures that are chosen based on Hansen's solubility parameters to optimize the solubility of PEG thereby enabling control over the graft density. The PEG thiol-gold model system enabled a thorough characterization of PEG films formed, while studies on a PEG silane-silicon system examined the versatility to be applied to any substrate-head group system by choosing an appropriate solvent pair. The ability of PEG films to resist non-specific adsorption of proteins was quantitatively assessed by full serum exposure studies and the binary solvent strategy was found to produce PEG films with optimal graft density to efficiently resist protein adsorption.

  1. Properties of diffraction gratings holographically recorded in poly(ethylene glycol)dimethacrylate-ionic liquid composites

    Science.gov (United States)

    Ellabban, Mostafa A.; Glavan, Gašper; Flauger, Peter; Klepp, Jürgen; Fally, Martin

    2017-05-01

    We investigated recording and readout of transmission gratings in composites of poly(ethylene glycol) dimethacrylate (PEGDMA) and ionic liquids (IL) in detail. Gratings were recorded using a two-wave mixing technique for different grating periods, exposures and a series of film thicknesses. The recording kinetics as well as the post-exposure behavior of the gratings were studied by diffraction experiments. We found that - depending on the parameters - different grating types (pure phase or mixed) are generated, and at elevated thicknesses strong light-induced scattering develops. Gratings with thicknesses up to 85 micrometers are of the required quality with excellent optical properties, thicker gratings exhibit strong detrimental light-induced scattering. The obtained results are particularly valuable when considering PEGDMA-ionic liquid composites for applications as e.g., holographic storage materials or as neutron optic diffractive elements.

  2. Rapid Heterotrophic Ossification with Cryopreserved Poly(ethylene glycol- Microencapsulated BMP2-Expressing MSCs

    Directory of Open Access Journals (Sweden)

    Jennifer Mumaw

    2012-01-01

    Full Text Available Autologous bone grafting is the most effective treatment for long-bone nonunions, but it poses considerable risks to donors, necessitating the development of alternative therapeutics. Poly(ethylene glycol (PEG microencapsulation and BMP2 transgene delivery are being developed together to induce rapid bone formation. However, methods to make these treatments available for clinical applications are presently lacking. In this study we used mesenchymal stem cells (MSCs due to their ease of harvest, replication potential, and immunomodulatory capabilities. MSCs were from sheep and pig due to their appeal as large animal models for bone nonunion. We demonstrated that cryopreservation of these microencapsulated MSCs did not affect their cell viability, adenoviral BMP2 production, or ability to initiate bone formation. Additionally, microspheres showed no appreciable damage from cryopreservation when examined with light and electron microscopy. These results validate the use of cryopreservation in preserving the viability and functionality of PEG-encapsulated BMP2-transduced MSCs.

  3. Hydrophilicity improvement in polyphenylsulfone nanofibrous filtration membranes through addition of polyethylene glycol

    Science.gov (United States)

    Kiani, Shirin; Mousavi, Seyed Mahmoud; Shahtahmassebi, Nasser; Saljoughi, Ehsan

    2015-12-01

    Novel hydrophilic polyphenylsulfone (PPSU) nanofibrous membrane was prepared by electrospinning of the PPSU solution blended with polyethylene glycol 400 (PEG 400). The influence of the PEG concentration on the membrane characteristics was studied using scanning electron microscopy (SEM), water contact angle measurement, and tensile test. Filtration performance of the membranes was investigated by measurement of pure water flux (PWF) and determination of the rejection values of the pollution indices during treatment of canned beans production wastewater. According to the results, blending the PPSU solution with 10 wt.% PEG 400 resulted in formation of a nanofibrous membrane with high porosity and increased mechanical strength which exhibited a low water contact angle of 8.9° and high water flux of 7920 L/m2h. Flux recovery of the mentioned membrane which was assessed by filtration of a solution containing bovine serum albumin (BSA) was 83% indicating a noticeable antifouling property.

  4. Lubricin: a versatile, biological anti-adhesive with properties comparable to polyethylene glycol.

    Science.gov (United States)

    Greene, George W; Martin, Lisandra L; Tabor, Rico F; Michalczyk, Agnes; Ackland, Leigh M; Horn, Roger

    2015-06-01

    Lubricin is a glycoprotein found in articular joints which has been recognized as being an important biological boundary lubricant molecule. Besides providing lubrication, we demonstrate, using a quartz crystal microbalance, that lubricin also exhibits anti-adhesive properties and is highly effective at preventing the non-specific adsorption of representative globular proteins and constituents of blood plasma. This impressive anti-adhesive property, combined with lubricin's ability to readily self-assemble to form dense, highly stable telechelic polymer brush layers on virtually any substrates, and its innate biocompatibility, makes it an attractive candidate for anti-adhesive and anti-fouling coatings. We show that coatings of lubricin protein are as effective as, or better than, self-assembled monolayers of polyethylene glycol over a wide range of pH and that this provides a simple, versatile, highly stable, and highly effective method of controlling unwanted adhesion to surfaces.

  5. Enzyme-Mediated Hydrolysis of Poly(ethylene glycol)-Supported Carbonates

    Institute of Scientific and Technical Information of China (English)

    K. Matsumoto; M. Shimojo; M. Nogawa; M. Okudomi

    2005-01-01

    @@ 1Introduction Enzymatic kinetic resolution of racemic alcohols or esters is known as a useful method for the preparation of optically active secondary alcohols. However, the work-up including the separation of the mixture of the remaining substrate and the resulting compound spend a lot of time and waste much amount of solvents. On the other hand, organic synthesis based on polymer supports has made rapid progress. Although the methodology is potentially useful for the easy separation of compounds obtained by the enzymatic reaction, there have been relatively few reports on enzymatic resolutions of using a polymer so far. We have noticed that using a watersoluble polymer could be suitable for enzymatic transformation. Here, we report the first example of an enzyme-mediated enantioselective hydrolysis of poly(ethylene glycol)(PEG)-supported substrates with a carbonate moiety to afford optically active compounds, and the method enables us to achieve the easy separation of the products[1]. See Scheme 1.

  6. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yutang; Kang, Huiying; Wang, Weilong; Liu, Hong; Gao, Xuenong [The Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

    2010-12-15

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic. (author)

  7. Study on polyethylene glycol/epoxy resin composite as a form-stable phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Fang Yutang, E-mail: ppytfang@scut.edu.c [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China); Kang Huiying; Wang Weilong; Liu Hong; Gao Xuenong [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education, South China University of Technology, Guangzhou 510640 (China)

    2010-12-15

    Form-stable polyethylene glycol (PEG)/epoxy resin (EP) composite as a novel phase change material (PCM) was prepared using casting molding method. In this new material, PEG acts as the latent heat storage material and EP polymer serves as the supporting material, which provides structural strength and prevents the leakage of the melted PEG. The structure and morphology of the novel composite were observed using Fourier transformation infrared spectroscope (FTIR) and scanning electronic microscope (SEM). The thermo-mechanical property and transition behavior were characterized by polarizing optical microscope (POM), static thermo-mechanical analysis (TMA) and differential scanning calorimeter (DSC). The experimental results show that, as a result of the physical tangled function of the epoxy resin carrier to the PEG segment, the composite macroscopically presents the solid-solid phase change characteristic.

  8. Characteristics of precipitation-formed polyethylene glycol microgels are controlled by molecular weight of reactants.

    Science.gov (United States)

    Thompson, Susan; Stukel, Jessica; AlNiemi, Abrar; Willits, Rebecca Kuntz

    2013-12-23

    This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer several advantages over traditional microsphere fabrication techniques. Contrary to emulsion, suspension, and dispersion techniques, microgels formed by precipitation are of uniform shape and size, i.e. low polydispersity index, without the use of organic solvents or stabilizers. The mild conditions of the precipitation reaction, customizable properties of the microgels, and low viscosity for injections make them applicable for in vivo purposes. Unlike other fabrication techniques, microgel characteristics can be modified by changing the starting polymer molecular weight. Increasing the starting PEG molecular weight increased microgel diameter and swelling ratio. Further modifications are suggested such as encapsulating molecules during microgel crosslinking. Simple adaptations to the PEG microgel building blocks are explored for future applications of microgels as drug delivery vehicles and tissue engineering scaffolds.

  9. Stereolithography of three-dimensional bioactive poly(ethylene glycol) constructs with encapsulated cells.

    Science.gov (United States)

    Arcaute, Karina; Mann, Brenda K; Wicker, Ryan B

    2006-09-01

    Stereolithography (SL) was used to fabricate complex 3-D poly(ethylene glycol) (PEG) hydrogels. Photopolymerization experiments were performed to characterize the solutions for use in SL, where the crosslinked depth (or hydrogel thickness) was measured at different laser energies and photoinitiator (PI) concentrations for two concentrations of PEG-dimethacrylate in solution (20% and 30% (w/v)). Hydrogel thickness was a strong function of PEG concentration, PI type and concentration, and energy dosage, and these results were utilized to successfully fabricate complex hydrogel structures using SL, including structures with internal channels of various orientations and multi-material structures. Additionally, human dermal fibroblasts were encapsulated in bioactive PEG photocrosslinked in SL. Cell viability was at least 87% at 2 and 24 h following fabrication. The results presented here indicate that the use of SL and photocrosslinkable biomaterials, such as photocrosslinkable PEG, appears feasible for fabricating complex bioactive scaffolds with living cells for a variety of important tissue engineering applications.

  10. Accumulation of magnetic iron oxide nanoparticles coated with variably sized polyethylene glycol in murine tumors.

    Science.gov (United States)

    Larsen, Esben Kjær Unmack; Nielsen, Thomas; Wittenborn, Thomas; Rydtoft, Louise Munk; Lokanathan, Arcot R; Hansen, Line; Østergaard, Leif; Kingshott, Peter; Howard, Kenneth A; Besenbacher, Flemming; Nielsen, Niels Chr; Kjems, Jørgen

    2012-04-07

    Iron oxide nanoparticles have found widespread applications in different areas including cell separation, drug delivery and as contrast agents. Due to water insolubility and stability issues, nanoparticles utilized for biological applications require coatings such as the commonly employed polyethylene glycol (PEG). Despite its frequent use, the influence of PEG coatings on the physicochemical and biological properties of iron nanoparticles has hitherto not been studied in detail. To address this, we studied the effect of 333-20,000 Da PEG coatings that resulted in larger hydrodynamic size, lower surface charge, longer circulation half-life, and lower uptake in macrophage cells when the particles were coated with high molecular weight (M(w)) PEG molecules. By use of magnetic resonance imaging, we show coating-dependent in vivo uptake in murine tumors with an optimal coating M(w) of 10,000 Da.

  11. Waterborne polyurethane single-ion electrolyte from aliphatic diisocyanate and various molecular length of polyethylene glycol

    Directory of Open Access Journals (Sweden)

    2007-03-01

    Full Text Available The waterborne polyurethane (WPU dispersions from the reaction of cycloaliphatic diisocyanates [4,4’-methylenebis(cyclohexyl isocyanate (H12MDI and isophorone diisocyanate (IPDI] and polyethylene glycol (PEG with various molecular lengths were synthesized using our modified acetone process. Differetial scanning calorimeter (DSC and Fourier transform infrared spectroscopy (FTIR were utilized to characterize WPU films for the behavior of their crystallinity and H-bonding of WPU films. The Tg value of WPU increases with increasing the molecular length of PEG, whereas the Tm of WPU decreases with increasing PEG length. Alternating current (AC impedance experiments were performed to determine the ionic conductivities of WPU films. The WPU gel electrolytes exhibits an ionic conductivity as high as ~ 10-5 S/cm at room temperature.

  12. Oleanolic acid liposomes with polyethylene glycol modification: promising antitumor drug delivery

    Directory of Open Access Journals (Sweden)

    Gao D

    2012-07-01

    Full Text Available Dawei Gao, Shengnan Tang, Qi TongApplied Chemical Key Laboratory of Hebei Province, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, ChinaBackground: Oleanolic acid is a pentacyclic triterpene present in many fruits and vegetables, and has received much attention on account of its biological properties. However, its poor solubility and low bioavailability limit its use. The objective of this study was to encapsulate oleanolic acid into nanoliposomes using the modified ethanol injection method.Methods: The liposomes contain a hydrophobic oleanolic acid core, an amphiphilic soybean lecithin monolayer, and a protective hydrophilic polyethylene glycol (PEG coating. During the preparation process, the formulations described were investigated by designing 34 orthogonal experiments as well as considering the effects of different physical characteristics. The four factors were the ratios of drug to soybean phosphatidylcholine (w/w, cholesterol (w/w, PEG-2000 (w/w, and temperature of phosphate-buffered saline at three different levels. We identified the optimized formulation which showed the most satisfactory lipid stability and particle formation. The morphology of the liposomes obtained was determined by transmission electron microscopy and atomic force microscopy. The existence of PEG in the liposome component was validated by Fourier transform infrared spectrum analysis.Results: The PEGylated liposomes dispersed individually and had diameters of around 110–200 nm. Encapsulation efficiency was more than 85%, as calculated by high-performance liquid chromatography and Sephadex® gel filtration. Furthermore, when compared with native oleanolic acid, the liposomal formulations showed better stability in vitro. Finally, the cytotoxicity of the oleanolic acid liposomes was evaluated using a microtiter tetrazolium assay.Conclusion: These results suggest that PEGylated liposomes would serve as a potent delivery vehicle

  13. 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)

  14. Hydrophilic polysulfone film prepared from polyethylene glycol monomethylether via coupling graft

    Science.gov (United States)

    Du, Ruikui; Gao, Baojiao; Li, Yanbin

    2013-06-01

    In the presence of acid-acceptor Na2CO3, the nucleophilic substitution between chloromethylated polysulfone (CMPSF) and polyethylene glycol monomethylether (PEGME) was conducted. Polyethylene glycol (PEG) was coupling-grafted onto the side chains of polysulfone (PSF) so that the graft copolymer PSF-g-PEG was prepared and the hydrophilic modification of polysulfone membrane material was realized. The chemical structure of PSF-g-PEG was characterized by FTIR and 1H NMR. The influence of the main factors on the coupling graft reaction was investigated. The water static contact angle of PSF-g-PEG membrane was determined and its property of resisting protein pollution was examined by using bovine serum albumin (BSA) as a model protein. The experimental results show that the coupling graft reaction between CMPSF and PEGME can proceed successfully, and the reaction of chloromethyl groups of CMPSF with the hydroxyl end groups of PEGME is a typical SN1 nucleophilic substitution reaction. The polarity of the solvents and the reaction temperature greatly influence the reaction. The suitable solvent is dimethyl acetamide with stronger polarity and 70 °C is a suitable reaction temperature. After reaction of 36 h, the grafting degree of PEG can reach 48 g/100 g and the product yield is about 73.6%. The contact angle of PSF-g-PEG membrane declines rapidly with the increase of PEG grafting degree, displaying the obvious enhancement of the hydrophilicity. The adsorption capacity of BSA on PSF-g-PEG membrane decreases remarkably with the increase of PEG grafting degree, showing excellent antifouling ability of PSF-g-PEG membrane for proteins.

  15. Stereolithography of spatially controlled multi-material bioactive poly(ethylene glycol) scaffolds.

    Science.gov (United States)

    Arcaute, Karina; Mann, Brenda; Wicker, Ryan

    2010-03-01

    Challenges remain in tissue engineering to control the spatial, mechanical, temporal and biochemical architectures of scaffolds. Unique capabilities of stereolithography (SL) for fabricating multi-material spatially controlled bioactive scaffolds were explored in this work. To accomplish multi-material builds, a mini-vat setup was designed allowing for self-aligning X-Y registration during fabrication. The mini-vat setup allowed the part to be easily removed and rinsed, and different photocrosslinkable solutions to be easily removed and added to the vat. Two photocrosslinkable hydrogel biopolymers, poly(ethylene glycol) dimethacrylate (PEG-dma, MW 1000) and poly(ethylene glycol) diacrylate (PEG-da, MW 3400), were used as the primary scaffold materials. Multi-material scaffolds were fabricated by including controlled concentrations of fluorescently labeled dextran, fluorescently labeled bioactive PEG or bioactive PEG in different regions of the scaffold. The presence of the fluorescent component in specific regions of the scaffold was analyzed with fluorescent microscopy, while human dermal fibroblast cells were seeded on top of the fabricated scaffolds with selective bioactivity and phase contrast microscopy images were used to show specific localization of cells in the regions patterned with bioactive PEG. Multi-material spatial control was successfully demonstrated in features down to 500 microm. In addition, the equilibrium swelling behavior of the two biopolymers after SL fabrication was determined and used to design constructs with the specified dimensions at the swollen state. The use of multi-material SL and the relative ease of conjugating different bioactive ligands or growth factors to PEG allows for the fabrication of tailored three-dimensional constructs with specified spatially controlled bioactivity.

  16. Norway spruce embryogenesis: changes in carbohydrate profile, structural development and response to polyethylene glycol.

    Science.gov (United States)

    Hudec, Lukáš; Konrádová, Hana; Hašková, Anna; Lipavská, Helena

    2016-05-01

    Two unrelated, geographically distinct, highly embryogenic lines of Norway spruce (Picea abies (L.) Karst.) were analysed to identify metabolic traits characteristic for lines with good yields of high-quality embryos. The results were compared with corresponding characteristics of a poorly productive line (low embryo yield, scarce high-quality embryos). The following carbohydrate profiles and spectra during maturation, desiccation and germination were identified as promising characteristics for line evaluation: a gradual decrease in total soluble carbohydrates with an increasing sucrose : hexose ratio during maturation; accumulation of raffinose family oligosaccharides resulting from desiccation and their rapid degradation at the start of germination; and a decrease in sucrose, increase in hexoses and the appearance of pinitol with proceeding germination. We propose that any deviation from this profile in an embryonic line is a symptom of inferior somatic embryo development. We further propose that a fatty acid spectrum dominated by linoleic acid (18 : 2) was a common feature of healthy spruce somatic embryos, although it was quite different from zygotic embryos mainly containing oleic acid (18 : 1). The responses of the lines to osmotic stress were evaluated based on comparison of control (without osmoticum) and polyethylene glycol (PEG)-exposed (PEG 4000) variants. Although genetically distinct, both highly embryogenic lines responded in a very similar manner, with the only difference being sensitivity to high concentrations of PEG. At an optimum PEG concentration (3.75 and 5%), which was line specific, negative effects of PEG on embryo germination were compensated for by a higher maturation efficiency so that the application of PEG at an appropriate concentration improved the yield of healthy germinants per gram of initial embryonal mass and accelerated the process. Polyethylene glycol application, however, resulted in no improvement of the poorly

  17. Infliximab attenuates activated charcoal and polyethylene glycol aspiration-induced lung injury in rats.

    Science.gov (United States)

    Güzel, Aygül; Günaydin, Mithat; Güzel, Ahmet; Alaçam, Hasan; Murat, Naci; Gacar, Ayhan; Güvenç, Tolga

    2012-04-01

    Aspiration is a serious complication of gastrointestinal (GI) decontamination procedure. Studies have shown that tumor necrosis factor-α (TNF-α) blockers have beneficial effects on lung injury. Therefore, the authors investigated the attenuation by infliximab (INF) on activated charcoal (AC)- and polyethylene glycol (PEG)-induced lung injury in rat model. Forty-two male Sprague-Dawley rats were allotted into 1 of 6 groups: saline (NS), activated charcoal (AC), polyethylene glycol (PEG), NS+INF treated, AC+INF treated, and PEG+INF treated. All materials were aspirated into the lungs at a volume of 1 mL/kg. Before aspiration, the rats were injected subcutaneously with INF. Seven days later, both lungs and serum specimens in all groups were evaluated histopathologically, immunohistochemically, and biochemically. Following aspiration of AC and PEG, evident histopathological changes were assigned in the lung tissue that were associated with increased expression of inducible nitric oxide synthase (iNOS), increased serum levels of oxidative stress markers (malondialdehyde [MDA], surfactant protein-D [SP-D], TNF-α), and decreased antioxidant enzyme (glutathione peroxidase [GSH-Px]) activities. INF treatment significantly decreased the elevated serum MDA and TNF-α levels and increased serum GSH-Px levels. Furthermore, the current results show that there is a significant reduction in the activity of iNOS in lung tissue and increased serum SP-D levels of AC and PEG aspiration-induced lung injury with INF treatment. These findings suggest that INF attenuates lung inflammation and prevents GI decontamination agent-induced lung injury in rats.

  18. Poly(ethylene glycol)s as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins

    Science.gov (United States)

    Guerra, Ruben; Taydakov, Ilya; Tonucci, Lucia; d’Alessandro, Nicola; Lamaty, Frederic; Martinez, Jean

    2017-01-01

    Summary The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene) glycols (PEGs), as safe grinding assisting agents (liquid-assisted grinding, LAG). A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents. In general, cleaner reaction profiles were observed in the presence of PEGs, compared to dry-grinding procedures.

  19. Modification of fibrinogen with poly(ethylene glycol) and its effects on fibrin clot characteristics.

    Science.gov (United States)

    Barker, T H; Fuller, G M; Klinger, M M; Feldman, D S; Hagood, J S

    2001-09-15

    The suitability of existing topical fibrin glue preparations for tissue sealing or local drug delivery applications is greatly limited by their poor mechanical properties and the limited capacity of fibrinogen (Fgn) to actively bind growth factors or other therapeutic agents. Poly(ethylene glycol) (PEG) offers potential solutions to these problems by providing a mechanism for increasing the number of crosslinks between adjacent fibrin monomer molecules or for covalently crosslinking Fgn to therapeutic agents. The feasibility of this approach requires the full biological activity, or clottability, of PE glycolated Fgn. This study characterizes the clot characteristics of Fgn modified to varying degrees with monofunctional succinimidyl propionate PEG (5000 Da). The data indicate that, although thrombin clotting times are significantly altered, Fgn maintains 90% of its capacity to clot upon the addition of up to 5 PEG/Fgn. Further derivatization significantly decreases the Fgn clottability. The addition of up to 5 PEG/Fgn has little, if any, effect on the kinetics of degradation by plasmin. The results suggest that limited modification of Fgn with lysine-reactive PEG allows therapeutic enhancement of fibrin glues. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 56: 529--535, 2001

  20. Electrochemical oxidation of polyethylene glycol in electroplating solution using paraffin composite copper hexacyanoferrate modified (PCCHM) anode.

    Science.gov (United States)

    Bejankiwar, Rajesh S; Basu, Abir; Cementi, Max

    2004-01-01

    Electrochemical oxidation of polyethylene glycol (PEG) in an acidic (pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified (PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.

  1. Electrochemical oxidation of polyethylene glycol in electroplating solution using paraffin composite copper hexacyanoferrate modified (PCCHM) anode

    Institute of Scientific and Technical Information of China (English)

    Rajesh S. Bejankiwar; Abir Basu; Max Cementi

    2004-01-01

    Electrochemical oxidation of polyethylene glycol(PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon(TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.

  2. Zinc Phthalocyanine Labelled Polyethylene Glycol: Preparation, Characterization, Interaction with Bovine Serum Albumin and Near Infrared Fluorescence Imaging in Vivo

    Directory of Open Access Journals (Sweden)

    Tianjun Liu

    2012-05-01

    Full Text Available Zinc phthalocyanine labelled polyethylene glycol was prepared to track and monitor the in vivo fate of polyethylene glycol. The chemical structures were characterized by nuclear magnetic resonance and infrared spectroscopy. Their light stability and fluorescence quantum yield were evaluated by UV-Visible and fluorescence spectroscopy methods. The interaction of zinc phthalocyanine labelled polyethylene glycol with bovine serum albumin was evaluated by fluorescence titration and isothermal titration calorimetry methods. Optical imaging in vivo, organ aggregation as well as distribution of fluorescence experiments for tracking polyethylene glycol were performed with zinc phthalocyanine labelled polyethylene glycol as fluorescent agent. Results show that zinc phthalocyanine labelled polyethylene glycol has good optical stability and high emission ability in the near infrared region. Imaging results demonstrate that zinc phthalocyanine labelled polyethylene glycol can track and monitor the in vivo process by near infrared fluorescence imaging, which implies its potential in biomaterials evaluation in vivo by a real-time noninvasive method.

  3. Spatially well-defined binary brushes of poly(ethylene glycol)s for micropatterning of active proteins on anti-fouling surfaces.

    Science.gov (United States)

    Xu, F J; Li, H Z; Li, J; Teo, Y H Eric; Zhu, C X; Kang, E T; Neoh, K G

    2008-12-01

    We report a novel method for micropatterning of active proteins on anti-fouling surfaces via spatially well-defined and dense binary poly(ethylene glycol)s (PEGs) brushes with controllable protein-docking sites. Binary brushes of poly(poly(ethylene glycol) methacrylate-co-poly(ethylene glycol)methyl ether methacrylate), or P(PEGMA-co-PEGMEMA), and poly(poly(ethylene glycol)methyl ether methacrylate), or P(PEGMEMA), were prepared via consecutive surface-initiated atom transfer radical polymerizations (SI-ATRPs) from a resist-micropatterned Si(100) wafer surface. The terminal hydroxyl groups on the side chains of PEGMA units in the P(PEGMA-co-PEGMEMA) microdomains were activated directly by 1,1'-carbonyldiimidazole (CDI) for the covalent coupling of human immunoglobulin (IgG) (as a model active protein). The resulting IgG-coupled PEG microdomains interact only and specifically with target anti-IgG, while the other PEG microregions effectively prevent specific and non-specific protein fouling. When extended to other active biomolecules, microarrays for specific and non-specific analyte interactions with a high signal-to-noise ratio could be readily tailored.

  4. Novel chitosan hydrogel formed by ethylene glycol chitosan, 1,6-diisocyanatohexan and polyethylene glycol-400 for tissue engineering scaffold: in vitro and in vivo evaluation.

    Science.gov (United States)

    Chen, Zhu; Zhao, Ming; Liu, Kang; Wan, Yuqing; Li, Xudong; Feng, Gang

    2014-08-01

    Traditional chitosan hydrogels were prepared by chemical or physical crosslinker, and both of the two kinds of hydrogels have their merits and demerits. In this study, researchers attempted to prepare one kind of chitosan hydrogel by slightly crosslinker, which could combine the advantages of the two kinds of hydrogels. In this experiment, the crosslinker was formed by a reaction between the isocyanate group of 1,6-diisocyanatohexan and the hydroxyl group of polyethylene glycol-400 (PEG-400), then the crosslinker reacted with the amidine and the hydroxyl group of ethylene glycol chitosan to form the network structure. Physical properties of the hydrogel were tested by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and biodegradation. Biocompatibility was assessed by cell implantation in vitro and the scaffold was used as a cartilage tissue engineering scaffold to repair a defect in rabbit knee joints in vivo. FTIR results show the formation of a covalent bond during thickening of the ethylene glycol chitosan. SEM and degradation experiments showed that the ethylene glycol chitosan hydrogel is a 3-D, porous, and degradable scaffold. The hydrogel contained 2% ethylene glycol chitosan and 10 μl crosslinker was selected for the biocompatibility experiment in vitro and in vivo. After chondrocytes were cultured in the ethylene glycol chitosan hydrogel scaffold for 1 week cells exhibited clustered growth and had generated extracellular matrix on the scaffold in vitro. The results in vivo showed that hydrogel-chondrocytes promoted the repair of defect in rabbits. Based on these results, it could be concluded that ethylene glycol chitosan hydrogel is a scaffold with excellent physicochemical properties and it is a promising tissue engineering scaffold.

  5. Preparation of poly(ethylene glycol/polylactide hybrid fibrous scaffolds for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Ni P

    2011-11-01

    Full Text Available PeiYan Ni, ShaoZhi Fu, Min Fan, Gang Guo, Shuai Shi, JinRong Peng, Feng Luo, ZhiYong QianState Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of ChinaAbstract: Polylactide (PLA electrospun fibers have been reported as a scaffold for bone tissue engineering application, however, the great hydrophobicity limits its broad application. In this study, the hybrid amphiphilic poly(ethylene glycol (PEG/hydrophobic PLA fibrous scaffolds exhibited improved morphology with regular and continuous fibers compared to corresponding blank PLA fiber mats. The prepared PEG/PLA fibrous scaffolds favored mesenchymal stem cell (MSC attachment and proliferation by providing an interconnected porous extracellular environment. Meanwhile, MSCs can penetrate into the fibrous scaffold through the interstitial pores and integrate well with the surrounding fibers, which is very important for favorable application in tissue engineering. More importantly, the electrospun hybrid PEG/PLA fibrous scaffolds can enhance MSCs to differentiate into bone-associated cells by comprehensively evaluating the representative markers of the osteogenic procedure with messenger ribonucleic acid quantitation and protein analysis. MSCs on the PEG/PLA fibrous scaffolds presented better differentiation potential with higher messenger ribonucleic acid expression of the earliest osteogenic marker Cbfa-1 and mid-stage osteogenic marker Col I. The significantly higher alkaline phosphatase activity of the PEG/PLA fibrous scaffolds indicated that these can enhance the differentiation of MSCs into osteoblast-like cells. Furthermore, the higher messenger ribonucleic acid level of the late osteogenic differentiation markers OCN (osteocalcin and OPN (osteopontin, accompanied by the positive Alizarin red S staining, showed better maturation of osteogenic induction on the PEG/PLA fibrous scaffolds at the

  6. Safety of polyethylene glycol 3350 solution in chronic constipation: randomized, placebo-controlled trial

    Directory of Open Access Journals (Sweden)

    McGraw T

    2016-07-01

    Full Text Available Thomas McGraw Global Medical Affairs, Merck & Co., Inc., Kenilworth, NJ, USA Purpose: To evaluate the safety and tolerability of aqueous solution concentrate (ASC of polyethylene glycol (PEG 3350 in patients with functional constipation.Patients and methods: The patients who met Rome III diagnostic criteria for functional constipation were randomized in this multicenter, randomized, placebo-controlled, single-blind study to receive once daily dose of PEG 3350 (17 g ASC or placebo solution for 14 days. The study comprised a screening period (visit 1, endoscopy procedure (visits 2 and 3, and follow-up telephone calls 30 days post-treatment. Safety end points included adverse events (AEs, clinical laboratory evaluations, vital signs, and others. The primary end points were the proportion of patients with abnormalities of the oral and esophageal mucosa, detected by visual and endoscopic examination of the oral cavity and esophagus, respectively, compared with placebo. A secondary objective was to compare the safety and tolerability of ASC by evaluating AEs or adverse drug reactions.Results: A total of 65 patients were enrolled in this study, 31 were randomized to PEG 3350 ASC and 34 were randomized to placebo, of which 62 patients completed the study. No patients in either group showed abnormalities in inflammation of the oral mucosa during visit 2 (before treatment or visit 3 (after treatment. Fewer abnormalities of the esophageal mucosa were observed in the PEG 3350 ASC group than in the placebo group on visit 3, with no significant difference in the proportion of abnormalities between the treatment groups. Overall, 40 treatment-emergent AEs were observed in 48.4% of patients treated with PEG 3350 ASC, and 41 treatment-emergent AEs were observed in 55.9% of patients treated with placebo – nonsignificant difference of -7.5% (95% CI: -21.3, 6.3 between treatment groups. No serious AEs or deaths were reported, and no patient discontinued because

  7. 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

  8. Novel bone wax based on poly(ethylene glycol)-calcium phosphate cement mixtures.

    Science.gov (United States)

    Brückner, Theresa; Schamel, Martha; Kübler, Alexander C; Groll, Jürgen; Gbureck, Uwe

    2016-03-01

    Classic bone wax is associated with drawbacks such as the risk of infection, inflammation and hindered osteogenesis. Here, we developed a novel self-setting bone wax on the basis of hydrophilic poly(ethylene glycol) (PEG) and hydroxyapatite (HA) forming calcium phosphate cement (CPC), to overcome the problems that are linked to the use of conventional beeswax systems. Amounts of up to 10 wt.% of pregelatinized starch were additionally supplemented as hemostatic agent. After exposure to a humid environment, the PEG phase dissolved and was exchanged by penetrating water that interacted with the HA precursor (tetracalcium phosphate (TTCP)/monetite) to form highly porous, nanocrystalline HA via a dissolution/precipitation reaction. Simultaneously, pregelatinized starch could gel and supply the bone wax with liquid sealing features. The novel bone wax formulation was found to be cohesive, malleable and after hardening under aqueous conditions, it had a mechanical performance (∼2.5 MPa compressive strength) that is comparable to that of cancellous bone. It withstood systolic blood pressure conditions for several days and showed antibacterial properties for almost one week, even though 60% of the incorporated drug vancomycin hydrochloride was already released after 8h of deposition by diffusion controlled processes. The study investigated the development of alternative bone waxes on the basis of a hydroxyapatite (HA) forming calcium phosphate cement (CPC) system. Conventional bone waxes are composed of non-biodegradable beeswax/vaseline mixtures that are often linked to infection, inflammation and hindered osteogenesis. We combined the usage of bioresorbable polymers, the supplementation with hemostatic agents and the incorporation of a mineral component to overcome those drawbacks. Self-setting CPC precursors (tetracalcium phosphate (TTCP), monetite) were embedded in a resorbable matrix of poly(ethylene glycol) (PEG) and supplemented with pregelatinized starch. This

  9. Physical and structural characteristics of acrylated poly(ethylene glycol)-alginate conjugates.

    Science.gov (United States)

    Davidovich-Pinhas, Maya; Bianco-Peled, Havazelet

    2011-07-01

    Transmucosal delivery of therapeutic agents is a non-invasive approach that utilizes human entry paths such as the nasal, buccal, rectal and vaginal routes. Mucoadhesive polymers have the ability to adhere to the mucus layer covering those surfaces and by that promote drug release, targeting and absorption. We have recently demonstrated that acrylated polymers display enhanced mucoadhesive properties due to their ability to covalently attach to mucus type glycoproteins. We have synthesized an acrylated poly(ethylene glycol)-alginate conjugate (alginate-PEGAc), a molecule which combines the gelation ability of alginate with the mucoadhesion properties arising from both the characteristics of poly(ethylene glycol) and the acrylate functionality. In the current investigation we introduce an in-depth characterization of the thermal, mechanical and structural properties of alginate-PEGAc aimed at gaining a better knowledge of its structure-function relations. The thermal stability, evaluated by thermal gravimetric analysis and differential scanning calorimetry, was compared with that of alginate and the intermediate product thiolated alginate. Dehydration at temperatures up to 200 °C was detected for all samples, followed by distinctive decomposition steps arising from the decomposition of the polymer backbone and side-chains. The nanostructure of the solutions and gels was evaluated from small angle X-ray scattering patterns, to which the "broken rod linked by flexible chain" model was fitted, and from rheology measurements. The maxima arising from electrostatic repulsion between the highly charged alginate chains was diminished for both modified alginate samples, suggesting that modification led to electrostatic screening. Alginate, thiolated alginate and alginate-PEGAc cross-linked with calcium ions demonstrated similar scattering patterns. However, different scattering intensities, gel strengths, and gelation kinetics were observed, suggesting a decrease in the

  10. Polyethylene glycol versus dual sugar assay for gastrointestinal permeability analysis: is it time to choose?

    Directory of Open Access Journals (Sweden)

    van Wijck K

    2012-07-01

    Full Text Available Kim van Wijck,1,2 Babs AFM Bessems,2 Hans MH van Eijk,2 Wim A Buurman,2 Cornelis HC Dejong,1,2 Kaatje Lenaerts1,21Top Institute Food and Nutrition, Wageningen, The Netherlands; 2Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht, NetherlandsBackground: Increased intestinal permeability is an important measure of disease activity and prognosis. Currently, many permeability tests are available and no consensus has been reached as to which test is most suitable. The aim of this study was to compare urinary probe excretion and accuracy of a polyethylene glycol (PEG assay and dual sugar assay in a double-blinded crossover study to evaluate probe excretion and the accuracy of both tests.Methods: Gastrointestinal permeability was measured in nine volunteers using PEG 400, PEG 1500, and PEG 3350 or lactulose-rhamnose. On 4 separate days, permeability was analyzed after oral intake of placebo or indomethacin, a drug known to increase intestinal permeability. Plasma intestinal fatty acid binding protein and calprotectin levels were determined to verify compromised intestinal integrity after indomethacin consumption. Urinary samples were collected at baseline, hourly up to 5 hours after probe intake, and between 5 and 24 hours. Urinary excretion of PEG and sugars was determined using high-pressure liquid chromatography-evaporative light scattering detection and liquid chromatography-mass spectrometry, respectively.Results: Intake of indomethacin increased plasma intestinal fatty acid-binding protein and calprotectin levels, reflecting loss of intestinal integrity and inflammation. In this state of indomethacin-induced gastrointestinal compromise, urinary excretion of the three PEG probes and lactulose increased compared with placebo. Urinary PEG 400 excretion, the PEG 3350/PEG 400 ratio, and the lactulose/rhamnose ratio could accurately detect indomethacin-induced increases in

  11. UV-patterned poly(ethylene glycol) matrix for microarray applications.

    Science.gov (United States)

    Larsson, Andréas; Du, Chun-Xia; Liedberg, Bo

    2007-11-01

    A versatile method to fabricate polymeric matrixes for microarray applications is demonstrated. Several different design strategies are presented where a variety of organic films, such as plastic polymers and self-assembled monolayers (SAMs) on planar silica and gold substrates, act as supports for the graft polymerization procedure. An ensemble of poly(ethylene glycol) methacrylate monomers are combined to obtain a matrix with desired properties: low nonspecific binding and easily accessible groups for postimmobilization of ligands. The free radical graft polymerization process occurs under irradiation with UV light in the 254-266 nm range, which offers the possibility to introduce patterns by means of a photomask. The arrays are created on inert and homogeneous coatings prepared either by graft polymerization of a methoxy-terminated PEG-methacrylate or self-assembly of a methoxy-terminated oligo(ethylene glycol) thiol. Carboxylic acid groups, introduced in the array spots either during graft polymerization or upon wet chemical conversion of hydroxyls, grant the capability to immobilize proteins and other molecules via free amine groups. Immobilization of fluorescent species as well as biotin followed by exposure to a fluorescently labeled antibody directed toward biotin display both excellent integrity of the spots and low nonspecific binding to the surrounding framework. Beside patterns of uniform height and size, an array of spots with varying thickness (a sort of gradient) is demonstrated. Such gradient samples enable us to address critical issues regarding the mechanism(s) behind spatially resolved free radical polymerization of methacrylates. It also offers a convenient route to optimize the matrix properties with respect to thickness, loading capacity, protein diffusion/penetration, and nonspecific binding.

  12. Leveling effects of ammonium salts on thermal stabilities of polyethylene glycols.

    Science.gov (United States)

    Xia, Juan; Song, Le Xin; Liu, Wei; Teng, Yue

    2013-10-28

    In this work, the thermal stabilities of a series of polyethylene glycols (PEG 4000, 6000 and 10000) were investigated after compositing with different kinds of inorganic salts, such as ammonium molybdate tetrahydrate (AMT), NH4VO3, (NH4)2SO4, NH4NO3, Na2SO4, Na2MoO4. It was first observed that all the ammonium salts exerted leveling effects for the thermal stabilities of the PEGs. In other words, the presence of the ammonium salts caused the occurrence of the maximum decomposition rates of the PEGs with the same repeat sequence but different chain lengths at almost the same temperatures. Leveling effects were defined by three parameters: leveling spans, leveling degrees and dispersion degrees of leveling. Further experiments revealed that leveling effects also occur in similar types of polymers: polypropylene glycols (PPG 2000, 3000 and 4000). A series of independent experiments including Fourier transformation infrared spectroscopy, Raman spectroscopy, differential scanning calorimetry, time-of-flight mass spectrometry, conductivity and field-emission scanning electron microscopy were performed to explore the origin of leveling effects. We consider that the interaction between inorganic ions and polymer molecules and the Hofmeister effect of ions in solution are two important factors affecting the stability of salt–polymer composites, because they can contribute to decrease the interaction between the polymer chains, leading to changes in the conformation and pyrolysis mode of polymers. We believe that the finding of leveling effects would be significant for both basic and applied research of soft matter.

  13. Design and synthesis of multifunctional poly(ethylene glycol)s using enzymatic catalysis for multivalent cancer drug delivery

    Science.gov (United States)

    Seo, Kwang Su

    The objective of this research was to design and synthesize multifunctional poly(ethylene glycol)s (PEG)s using enzyme-catalyzed reactions for multivalent targeted drug delivery. Based on computer simulation for optimum folate binding, a four-arm PEG star topology with Mn = 1000 g/mol was proposed. First, a four-functional core based on tetraethylene glycol (TEG) was designed and synthesized using transesterification and Michael addition reactions in the presence of Candida antarctica lipase B (CALB) as a biocatalyst. The four-functional core (HO)2-TEG-(OH)2 core was successfully prepared by the CALB-catalyzed transesterification of vinyl acrylate (VA) with TEG and then Michael addition of diethanolamine to the resulting TEG diacrylate with/without the use of solvent. The functional PEG arms with fluorescein isothiocyanate (FITC) and folic acid (FA) were prepared using both traditional organic chemistry and enzyme-catalyzed reactions. FITC was reacted with the amine group of H2N-PEG-OH in the presence of triethylamine via nucleophilic addition onto the isothiocyanate group. Then, divinyl adipate (DVA) was transesterified with the FITC-PEG-OH product in the presence of CALB to produce the FITC-PEG vinyl ester that will be attached to the four-functional core via CALC-catalyzed transesterification. For the synthesis of FA-PEG vinyl ester arm, DVA was first reacted with PEG-monobenzyl ether (BzPEG-OH) in bulk in the presence of CALB. The BzPEG vinyl ester was then transesterified with 12-bromo-1-dodecanol in the presence of CALB. Finally, BzPEG-Br was attached to FA exclusively in the gamma position using a new method. The thesis also discusses fundamental studies that were carried out in order to get better understanding of enzyme catalyzed transesterification and Michael addition reactions. First, in an effort to investigate the effects of reagent and enzyme concentrations in transesterification, vinyl methacrylate (VMA) was reacted with 2-(hydroxyethyl) acrylate (2

  14. Synthesis and Characterization of a Novel Functional Biodegradable Copolymer-Poly(lactic acid-4-hydroxyproline-polyethylene glycol)

    Institute of Scientific and Technical Information of China (English)

    Jiu Fang DUAN; Yu Bin ZHENG

    2006-01-01

    A series of poly(lactic acid-4-hydroxyproline-polyethylene glycol) (PLA-Hpr-PEG) copolymers were synthesized by direct melt copolymerization of D,L-lactic acid and 4-hydroxyproline with different feed amount of polyethylene glycol (PEG) 0.1%, 0.5%, 1% and 5%, respectively. The properties of these copolymers were characterized by using IR spectroscopy, proton nuclear magnetic resonance (1H-NMR) spectroscopy, gel permeation chromatography (GPC), X-ray diffraction and differential scaning calorimetry (DSC). PLA-Hpr-PEG are amorphous copolymers. Copolymers showed increasing water uptake capacity with increasing PEG percentage in the feed, which result in an increasing degradable rate in phosphate buffer solution (pH 7.4) at 37℃.

  15. Synthesis and characterization of three-arm star-shaped polyethylene glycols with 1,1,1-trihydroxmethylpropane as cores

    Institute of Scientific and Technical Information of China (English)

    Kangcheng WANG; Wei HUANG; Yongfeng ZHOU; Deyue YAN

    2008-01-01

    A small molecule core (TMP,SK3) with three terminal carboxyl groups was synthesized successfully by the reaction of 1,1,1,trihydroxymethylpropane with the excessive sebacic acid diacetic anhydride (SK). Then, the core molecule was used as a coupling agent to condensate with polyethylene glycols (PEG) of different molecular weights or polyethylene glycol monomethyl ether (PEGm) in the presence of stannous octoate as catalyst and diphenyl ether as an azeotropic agent to remove water. Thus, the three,arm star,shaped PEGs was obtained successfully and characterized by IH,NMR,DSC, GPC and XRD etc. DSC measurements indicate that the crystallizing and the melting temperatures of the three,arm star,shaped PEGs were different from those of the corresponding linear PEG because the existence of TMP,SK3 altered its crystallizing velocity and perfect degree of crystallization.

  16. Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation

    DEFF Research Database (Denmark)

    Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun;

    2015-01-01

    seeds at 25°C, a thermoinhibitory temperature. Before twodimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two...

  17. Regulation of inter- and intramolecular ligation with T4 DNA ligase in the presence of polyethylene glycol.

    OpenAIRE

    Hayashi, K.; NAKAZAWA, M.; Ishizaki, Y; Hiraoka, N.; Obayashi, A

    1986-01-01

    Polyethylene glycol (PEG) stimulates ligation with T4 DNA ligase. In 10% (w/v) PEG 6,000 solutions, only intermolecular ligation is enhanced by monovalent cations, while both inter- and intramolecular ligation occur without their presence. Similar stimulation was also caused by divalent cations or polyamines in the PEG 6,000 solutions. Such properties of the ligase could be applied to control the extent of inter- and intramolecular ligation. Ligation with cations or polyamines in 10% PEG 6,00...

  18. Poly(ethylene glycols as grinding additives in the mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins

    Directory of Open Access Journals (Sweden)

    Andrea Mascitti

    2017-01-01

    Full Text Available The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene glycols (PEGs, as safe grinding assisting agents (liquid-assisted grinding, LAG. A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents. In general, cleaner reaction profiles were observed in the presence of PEGs, compared to dry-grinding procedures.

  19. Polyethylene glycol gold-nanoparticles: Facile nanostructuration of doxorubicin and its complex with DNA molecules for SERS detection

    Science.gov (United States)

    Spadavecchia, Jolanda; Perumal, Ramesh; Casale, Sandra; Krafft, Jean-Marc; Methivier, Christophe; Pradier, Claire-Marie

    2016-03-01

    We report the synthesis of dicarboxylic acid-terminated polyethylene-glycol (PEG)-gold nanoparticles by a simple one-step method, and their further use to form nanostructured surfaces for biomolecule immobilization. The synthesized nano-scale particles were conjugated with probe/target oligonucleotides in order to evaluate intercalation phenomenon in the presence of doxorubicin drug via surface enhanced Raman spectroscopy (SERS) analysis.

  20. Antifouling properties of poly(methyl methacrylate) films grafted with poly(ethylene glycol) monoacrylate immersed in seawater

    OpenAIRE

    Iguerb, O.; Poleunis, C.; Mazeas, F.; Compere, C.; Bertrand, P.

    2008-01-01

    Biofouling of all structures immersed in seawater constitutes an important problem, and many strategies are currently being developed to tackle it. In this context, our previous work shows that poly(ethylene glycol) monoacrylate (PEGA) macromonomer grafted on preoxidized poly(methyl methacrylate) (PMMAox) films exhibits an excellent repellency against the bovine serum albumin used as a model protein. This study aims to evaluate the following: (1) the prevention of a marine extract material ad...

  1. Measurements of attractive forces between proteins and end-grafted poly(ethylene glycol) chains

    OpenAIRE

    Sheth, S. R.; Leckband, D.

    1997-01-01

    The surface force apparatus was used to measure directly the molecular forces between streptavidin and lipid bilayers displaying grafted Mr 2,000 poly(ethylene glycol) (PEG). These measurements provide direct evidence for the formation of relatively strong attractive forces between PEG and protein. At low compressive loads, the forces were repulsive, but they became attractive when the proteins were pressed into the polymer layer at higher loads. The adhesion was sufficiently robust that sepa...

  2. 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....

  3. SYNTHESIS OF NOVEL BLOCK COPOLYMERS OF POLY(3-HYDROXYBUTYRIC ACID) WITH POLY(ETHYLENE GLYCOL) THROUGH ANIONIC POLYMERISATION

    Institute of Scientific and Technical Information of China (English)

    Xin-tao Shuai; Zbigniew; Jedlinski, Qiang Luo; Nozirow Farhod

    2000-01-01

    A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-opening polymerization of β-butyrolactone (β-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which were prepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (Mn = 2000, 4000 and 6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterized by IR, 1H-NMR and GPC.

  4. Convenient synthesis of heterobifunctional poly(ethylene glycol) suitable for the functionalization of iron oxide nanoparticles for biomedical applications

    OpenAIRE

    Passemard, Solène; Städler, Davide; Ucnova, Lucia; Schneiter, Guillaume Stéphane; Kong, Phally; Bonacina, Luigi; Gerber-Lemaire, Sandrine

    2013-01-01

    A straightforward route is proposed for the multi-gram scale synthesis of heterobifunctional poly(ethylene glycol) (PEG) oligomers containing combination of triethyloxysilane extremity for surface modification of metal oxides and amino or azido active end groups for further functionalization. The suitability of these PEG derivatives to be conjugated to nanomaterials was shown by pegylation of ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles (NPs), followed by functionalization wi...

  5. Second-step concentration of viruses in drinking and surface waters using polyethylene glycol hydroextraction.

    Science.gov (United States)

    Ramia, S; Sattar, S A

    1979-05-01

    In our laboratory, virus adsorbed to talc--Celite layers is eluted with 100 mL of 10% fetal calf serum (FCS) in normal saline (pH 9.0). A further 10-fold reduction in the volume of the eluate was necessary before its inoculation into cell cultures. A 100-mL volume of an experimentally contaminated sample was placed in a dialysis sac and hydroextracted overnight (4 degrees C) with polyethylene glycol (PEG) 6000. The viscous material remaining in the sac was resuspended in 10 mL of Earle's balanced salt solution. After membrane filtration (0.2 micron), the concentrate was plaque assayed in BS-C-1 cells. Using this technique, recoveries of five laboratory-adapted enteric viruses (polio 1, echo 6, coxsackie B5, coxackie A9, and reo 3) and four freshly isolated enteric virus strains (polio 1, echo 1, coxsackie B3, and reo) ranged from 87 to 97%. In comparative tests, PEG hydroextraction was simpler and superior to organic flocculation.

  6. Biomechanical Performances of Networked Polyethylene Glycol Diacrylate: Effect of Photoinitiator Concentration, Temperature, and Incubation Time

    Directory of Open Access Journals (Sweden)

    Morshed Khandaker

    2016-01-01

    Full Text Available Nutrient conduit networks can be introduced within the Polyethylene Glycol Diacrylate (PEGDA tissue construct to enable cells to survive in the scaffold. Nutrient conduit networks can be created on PEGDA by macrochannel to nanochannel fabrication techniques. Such networks can influence the mechanical and cell activities of PEGDA scaffold. There is no study conducted to evaluate the effect of nutrient conduit networks on the maximum tensile stress and cell activities of the tissue scaffold. The study aimed to explore the influence of the network architecture on the maximum tensile stress of PEGDA scaffold and compared with the nonnetworked PEGDA scaffold. Our study found that there are 1.78 and 2.23 times decrease of maximum tensile stress due to the introduction of nutrient conduit networks to the PEGDA scaffold at 23°C and 37°C temperature conditions, respectively. This study also found statistically significant effect of network architecture, PI concentration, temperature, and wait time on the maximum failure stress of PEGDA samples (P value < 0.05. Cell viability results demonstrated that networked PEGDA hydrogels possessed increased viability compared to nonnetworked and decreased viability with increased photoinitiator concentrations. The results of this study can be used for the design of PEGDA scaffold with macrosize nutrient conduit network channels.

  7. Spatially controlled bacterial adhesion using surface-patterned poly(ethylene glycol) hydrogels.

    Science.gov (United States)

    Krsko, Peter; Kaplan, Jeffrey B; Libera, Matthew

    2009-02-01

    We constructed surface-patterned hydrogels using low-energy focused electron beams to locally crosslink poly(ethylene glycol) (PEG) thin films on silanized glass substrates. Derived from electron-beam lithography, this technique was used to create patterned hydrogels with well-defined spatial positions and degrees of swelling. We found that cells of the bacterium Staphylococcus epidermidis adhered to and grew on the silanized glass substrates. These cells did not, however, adhere to surfaces covered by high-swelling lightly crosslinked PEG hydrogels. This finding is consistent with the cell-repulsiveness generally attributed to PEGylated surfaces. In contrast, S. epidermidis cells did adhere to surfaces covered by low-swelling highly crosslinked hydrogels. By creating precise patterns of repulsive hydrogels combined with adhesive hydrogels or with exposed glass substrate, we were able to spatially control the adhesion of S. epidermidis. Significantly, adhesive areas small enough to trap single bacterial cells could be fabricated. The results suggest that the lateral confinement imposed by cell-repulsive hydrogels hindered the cell proliferation and development into larger bacterial colonies.

  8. Role of polyvinyl alcohol in the conductivity behaviour of polyethylene glycol-based composite gel electrolytes

    Indian Academy of Sciences (India)

    S K Patel; R B Patel; A Awadhia; N Chand; S L Agrawal

    2007-09-01

    An attempt has been made in the present work to combine gel and composite polymer electrolyte routes together to form a composite polymeric gel electrolyte that is expected to possess high ionic conductivity with good mechanical integrity. Polyethylene glycol (PEG) based composite gel electrolytes using polyvinyl alcohol (PVA) as guest polymer have been synthesized with 1 molar solution of ammonium thiocyanate (NH4SCN) in dimethyl sulphoxide (DMSO) and electrically characterized. The ionic conductivity measurements indicate that PEG : PVA : NH4SCN-based composite gel electrolytes are superior (max = 5.7 × 10−2 S cm-1) to pristine electrolytes (PEG : NH4SCN system) and conductivity variation with filler concentration remains within an order of magnitude. The observed conductivity maxima have been correlated to PEG : PVA : NH4SCN- and PVA : NH4SCN-type complexes. Temperature dependence of conductivity profiles exhibits Arrhenius behaviour in low temperature regime followed by VTF character at higher temperature.

  9. Low doses of TiO2-polyethylene glycol nanoparticles stimulate proliferation of hepatocyte cells.

    Science.gov (United States)

    Sun, Qingqing; Kanehira, Koki; Taniguchi, Akiyoshi

    2016-01-01

    This paper describes the effect of low concentrations of 100 nm polyethylene glycol-modified TiO2 nanoparticles (TiO2-PEG NPs) on HepG2 hepatocellular carcinoma cells. Proliferation of HepG2 cells increased significantly when the cells were exposed to low doses (TiO2-PEG NPs. These results were further confirmed by cell counting experiments and cell cycle assays. Cellular uptake assays were performed to determine why HepG2 cells proliferate with low-dose exposure to TiO2-PEG NPs. The results showed that exposure to lower doses of NPs led to less cellular uptake, which in turn decreased cytotoxicity. We therefore hypothesized that TiO2-PEG NPs could affect the activity of hepatocyte growth factor receptors (HGFRs), which bind to hepatocyte growth factor and stimulate cell proliferation. The localization of HGFRs on the surface of the cell membrane was detected via immunofluorescence staining and confocal microscopy. The results showed that HGFRs aggregate after exposure to TiO2-PEG NPs. In conclusion, our results indicate that TiO2-PEG NPs have the potential to promote proliferation of HepG2 cells through HGFR aggregation and suggest that NPs not only exhibit cytotoxicity but also affect cellular responses.

  10. Synthesis, characterization and preliminary cytotoxicity assays of poly(ethylene glycol)-malonato-Pt-DACH conjugates.

    Science.gov (United States)

    Furin, Alessia; Guiotto, Andrea; Baccichetti, Franca; Pasut, Gianfranco; Deuschel, Christine; Bertani, Roberta; Veronese, Francesco M

    2003-01-01

    Oxalate 1,2-diaminocyclohexane platinum (oxaliplatin(R)), a successfully employed platinum compound belonging to the family of Pt-DACH complexes, has been conjugated to different molecular weight poly(ethylene glycols) (PEG) by means of peptide spacers and a malonic acid bidentate residue. Tri- and tetrapeptidic substrates of lysosomal enzymes were used in order to increase the release of Pt-DACH complex inside the cell following endocytosis and enzymatic degradation of the peptide spacer. Other aminoacids (e.g. norleucine) have been also employed. 1H-NMR of some conjugates was performed as characterisation of the product, while 195Pt-NMR analysis was carried out to detect the rearrangement of the platinum complex from the Pt(O,O) to the Pt(O,N) form. The compound PEG(5000)-Nle-malonato-Pt-DACH (4) has been tested against L1210-implanted mice and showed and appreciable increase in cytotoxicity as compared to the reference standard Cl(2)PtDACH.

  11. Covalent functionalization of graphene oxide with biocompatible poly(ethylene glycol) for delivery of paclitaxel.

    Science.gov (United States)

    Xu, Zhiyuan; Wang, Song; Li, Yongjun; Wang, Mingwei; Shi, Ping; Huang, Xiaoyu

    2014-10-08

    Graphene oxide (GO), a novel 2D nanomaterial prepared by the oxidation of natural graphite, has been paid much attention in the area of drug delivery due to good biocompatibility and low toxicity. In the present work, 6-armed poly(ethylene glycol) was covalently introduced into the surface of GO sheets via a facile amidation process under mild conditions, making the modified GO, GO-PEG (PEG: 65 wt %, size: 50-200 nm), stable and biocompatible in physiological solution. This nanosized GO-PEG was found to be nontoxic to human lung cancer A549 and human breast cancer MCF-7 cells via cell viability assay. Furthermore, paclitaxel (PTX), a widely used cancer chemotherapy drug, was conjugated onto GO-PEG via π-π stacking and hydrophobic interactions to afford a nanocomplex of GO-PEG/PTX with a relatively high loading capacity for PTX (11.2 wt %). This complex could quickly enter into A549 and MCF-7 cells evidenced by inverted fluorescence microscopy using Fluorescein isothiocyanate as a probe, and it also showed remarkably high cytotoxicity to A549 and MCF-7 cells in a broad range of concentration of PTX and time compared to free PTX. This kind of nanoscale drug delivery system on the basis of PEGylated GO may find potential application in biomedicine.

  12. Development of Electrically Conductive Oligo(polyethylene Glycol) Fumarate-Polypyrrole Hydrogels for Nerve Regeneration

    Science.gov (United States)

    Runge, M. Brett; Dadsetan, Mahrokh; Baltrusaitis, Jonas; Ruesink, Terry; Lu, Lichun; Windebank, Anthony J.; Yaszemski, Michael J.

    2014-01-01

    Electrically conductive hydrogel composites consisting of oligo(polyethylene glycol) fumarate (OPF) and polypyrrole (PPy) were developed for applications in nerve regeneration. OPF-PPy scaffolds were synthesized using three different anions: naphthalene-2-sulfonic acid sodium salt (NSA), dodecylbenzenesulfonic acid sodium salt (DBSA), and dioctyl sulfosuccinate sodium salt (DOSS). Scaffolds were characterized by ATR-FTIR, XPS, AFM, dynamic mechanical analysis, electrical resistivity measurements, and swelling experiments. OPF-PPy scaffolds were shown to consist of up to 25 mol% polypyrrole with a compressive modulus ranging from 265 to 323 kPa and a sheet resistance ranging from 6 to 30 × 103 Ohms/square. In vitro studies using PC12 cells showed OPF-PPy materials had no cytotoxicity and PC12 cells showed distinctly better cell attachment and an increase in the percent of neurite bearing cells on OPF-PPy materials compared to OPF. The neurite lengths of PC12 cells were significantly higher on OPF-PPyNSA and OPF-PPyDBSA. These results show that electrically conductive OPF-PPy hydrogels are promising candidates for future applications in nerve regeneration. PMID:20942380

  13. Polyethylene-glycol-modified single-walled carbon nanotubes for intra-articular delivery to chondrocytes.

    Science.gov (United States)

    Sacchetti, Cristiano; Liu-Bryan, Ru; Magrini, Andrea; Rosato, Nicola; Bottini, Nunzio; Bottini, Massimo

    2014-12-23

    Osteoarthritis (OA) is a common and debilitating degenerative disease of articular joints for which no disease-modifying medical therapy is currently available. Inefficient delivery of pharmacologic agents into cartilage-resident chondrocytes after systemic administration has been a limitation to the development of anti-OA medications. Direct intra-articular injection enables delivery of high concentrations of agents in close proximity to chondrocytes; however, the efficacy of this approach is limited by the fast clearance of small molecules and biomacromolecules after injection into the synovial cavity. Coupling of pharmacologic agents with drug delivery systems able to enhance their residence time and cartilage penetration can enhance the effectiveness of intra-articularly injected anti-OA medications. Herein we describe an efficient intra-articular delivery nanosystem based on single-walled carbon nanotubes (SWCNTs) modified with polyethylene glycol (PEG) chains (PEG-SWCNTs). We show that PEG-SWCNTs are capable to persist in the joint cavity for a prolonged time, enter the cartilage matrix, and deliver gene inhibitors into chondrocytes of both healthy and OA mice. PEG-SWCNT nanoparticles did not elicit systemic or local side effects. Our data suggest that PEG-SWCNTs represent a biocompatible and effective nanocarrier for intra-articular delivery of agents to chondrocytes.

  14. Amphiphilic copolymers reduce aggregation of unfolded lysozyme more effectively than polyethylene glycol

    Science.gov (United States)

    Chin, Jaemin; Mustafi, Devkumar; Poellmann, Michael J.; Lee, Raphael C.

    2017-02-01

    Certain amphiphilic block copolymers are known to prevent aggregation of unfolded proteins. To better understand the mechanism of this effect, the optical properties of heat-denatured and dithiothreitol reduced lysozyme were evaluated with respect to controls using UV–Vis spectroscopy, transmission electron microscopy (TEM) and circular dichroism (CD) measurements. Then, the effects of adding Polyethylene Glycol (8000 Da), the triblock surfactant Poloxamer 188 (P188), and the tetrablock copolymer Tetronic 1107 (T1107) to the lysozyme solution were compared. Overall, T1107 was found to be more effective than P188 in inhibiting aggregation, while PEG exhibited no efficacy. TEM imaging of heat-denatured and reduced lysozymes revealed spherical aggregates with on average 250–450 nm diameter. Using CD, more soluble lysozyme was recovered with T1107 than P188 with β-sheet secondary structure. The greater effectiveness of the larger T1107 in preventing aggregation of unfolded lysozyme than the smaller P188 and PEG points to steric hindrance at play; signifying the importance of size match between the hydrophobic region of denatured protein and that of amphiphilic copolymers. Thus, our results corroborate that certain multi-block copolymers are effective in preventing heat-induced aggregation of reduced lysozymes and future studies warrant more detailed focus on specific applications of these copolymers.

  15. Asymmetric poly(ethylene glycol) star polymers with a cholic acid core and their aggregation properties.

    Science.gov (United States)

    Luo, Juntao; Giguère, Guillaume; Zhu, X X

    2009-04-13

    Poly(ethylene glycol) (PEG) arms are grafted onto a cholic acid core via anionic polymerization, yielding star-shaped polymers with a unique asymmetric structure with facial amphiphilicity. Well-defined cholic acid-PEG(4) stars (polydispersity index, ca. 1.05) with tunable molar masses (ca. 1000-13,000) were obtained and characterized by the use of size exclusion chromatography, MALDI-TOF mass spectrometry, NMR spectroscopy, and thermal analysis. The asymmetric star polymers were found to aggregate differently from cholic acid salt. The critical aggregation concentrations of the star polymers were determined by surface tension measurements, and spherical aggregates of the polymers with different PEG chain lengths were observed by transmission electron microscopy using the freeze-fracture etching technique. The elongated aggregates formed by the sodium salt of cholic acid were also observed. The hydrodynamic diameters of the aggregates were also measured using dynamic light scattering technique. The formation of aggregates makes them interesting systems as potential drug carriers.

  16. In vivo degradation of polyurethane foam with 55 wt % polyethylene glycol.

    Science.gov (United States)

    Broekema, Ferdinand I; Van Leeuwen, M Barbara M; Van Minnen, Baucke; Bos, Rudolf R M

    2015-11-01

    Most topical hemostatic agents are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission while adjustments in the production process of these materials are limited. A synthetic hemostatic agent based on polyurethane (PU) and polyethylene glycol (PEG) was developed to overcome these disadvantages. The goal of this study was to compare the degradation process of this biomaterial to collagen and gelatin hemostatic agents. Samples of the test materials were implanted subcutaneously in both rats and rabbits. The animals were sacrificed at certain time intervals up to three years and the explanted samples were microscopically assessed. The histological examination showed a comparable pattern of degradation for the different test materials. Remnants of gelatin and collagen were seen up to 26 and 39 weeks, respectively. For PU, it took up to three years before micro-particles of the material were no longer detected. All biomaterials showed a good biocompatibility and no severe foreign body reactions occurred. The good biocompatibility and predictable pattern of resorption indicate that PU can be used as a topical hemostatic agent. However, a degradation time comparable to collagen and gelatin would be favorable.

  17. In situ formation of leak-free polyethylene glycol (PEG) membranes in microfluidic fuel cells.

    Science.gov (United States)

    Ho, W F; Lim, K M; Yang, K-L

    2016-11-29

    Membraneless microfluidic fuel cells operated under two co-laminar flows often face serious fuel cross-over problems, especially when flow rates are close to zero. In this study, we show that polyethylene glycol (PEG) monomers can be cross-linked inside microfluidic channels to form leak-free PEG membranes, which prevent mixing of two incompatible electrolyte solutions while allowing diffusion of certain molecules (e.g. glucose) and ions. By using PEG monomers of different molecular weights and cross-linking conditions, we are able to tailor selectivity of the membrane to allow passage of glucose while blocking larger molecules such as trypan blue. As a proof of principle, a microfluidic fuel cell with a PEG membrane and two incompatible electrolytes (acid and base) is demonstrated. Thanks to the leak-free nature of the PEG membrane, these two electrolytes do not mix together even at very slow flow rates. This microfluidic fuel cell is able to generate a voltage up to ∼450 mV from 10 mM of glucose with a flow rate of 20 μL min(-1). This microfluidic fuel cell is potentially useful as a miniature power source for many applications.

  18. Nanocomposites of Molybdenum Disulfide/Methoxy Polyethylene Glycol-co-Polypyrrole for Amplified Photoacoustic Signal.

    Science.gov (United States)

    Lee, Hohyeon; Kim, Haemin; Nguyen, Thang Phan; Chang, Jin Ho; Kim, Soo Young; Kim, Hyuncheol; Kang, Eunah

    2016-11-02

    Photoacoustic activity is the generation of an ultrasonic signal via thermal expansion or bubble formation, stimulated by laser irradiation. Photoacoustic nanoplatforms have recently gained focus for application in bioelectric interfaces. Various photoacoustic material types have been evaluated, including gold nanoparticles, semiconductive π-conjugating polymers (SP), etc. In this study, surfactant-free methoxy-polyethylene glycol-co-polypyrrole copolymer (mPEG-co-PPyr) nanoparticles (NPs) and mPEG-co-PPyr NP/molybdenum disulfide (mPEG-co-PPyr/MoS2) nanocomposites (NCs) were prepared and their photoacoustic activity was demonstrated. The mPEG-co-PPyr NPs and mPEG-co-PPyr/MoS2 NCs both showed photoacoustic signal activity. The mPEG-co-PPyr/MoS2 NCs presented a higher photoacoustic signal amplitude at 700 nm than the mPEG-co-PPyr NPs. The enhanced photoacoustic activity of the mPEG-co-PPyr/MoS2 NCs might be attributed to heterogeneous interfacial contact between mPEG-co-PPyr and the MoS2 nanosheets due to complex formation. Laser ablation of MoS2 might elevate the local temperature and facilitate the thermal conductive transfer in the mPEG-co-PPyr/MoS2 NCs, amplifying PA signal. Our study, for the first time, demonstrates enhanced PA activity in SP/transition metal disulfide (TMD) composites as photoacoustic nanoplatforms.

  19. Mid-infrared spectroscopic investigation of the perfect vitrification of poly(ethylene glycol) aqueous solutions.

    Science.gov (United States)

    Gemmei-Ide, Makoto; Miyashita, Takashi; Kagaya, Shigehiro; Kitano, Hiromi

    2015-10-01

    Crystallization/recrystallization behaviors of poly(ethylene glycol) (PEG) aqueous solutions with water contents (WC's) of ∼36-51 wt % were investigated by temperature-variable mid-infrared spectroscopy. At a WC of 43.2 wt %, crystallization and recrystallization of water and PEG were not observed. At this specific WC value (WCPV), perfect vitrification occurred. Below and above the WCPV value, crystallization/recrystallization behaviors changed drastically. The crystallization temperature below WCPV (237 K) was ∼10 K greater than that above WCPV (226 K). Recrystallization above and below WCPV occurred in one (213 K) and two (198 and 210 K) steps, respectively. These findings resulted from the difference in the (re)crystallization behaviors of water molecules associated with PEG chains with helical and random-coil conformations. These two types of water molecules might have limiting concentrations for their (re)crystallization, indicating that perfect vitrification might have occurred when the concentrations of the two types of water molecules were less than the limiting concentrations of their (re)crystallization.

  20. Injectable Dopamine-Modified Poly(ethylene glycol) Nanocomposite Hydrogel with Enhanced Adhesive Property and Bioactivity

    Science.gov (United States)

    2015-01-01

    A synthetic mimic of mussel adhesive protein, dopamine-modified four-armed poly(ethylene glycol) (PEG-D4), was combined with a synthetic nanosilicate, Laponite (Na0.7+(Mg5.5Li0.3Si8)O20(OH)4)0.7–), to form an injectable naoncomposite tissue adhesive hydrogel. Incorporation of up to 2 wt % Laponite significantly reduced the cure time while enhancing the bulk mechanical and adhesive properties of the adhesive due to strong interfacial binding between dopamine and Laponite. The addition of Laponite did not alter the degradation rate and cytocompatibility of PEG-D4 adhesive. On the basis of subcutaneous implantation in rat, PEG-D4 nanocomposite hydrogels elicited minimal inflammatory response and exhibited an enhanced level of cellular infiltration as compared to Laponite-free samples. The addition of Laponite is potentially a simple and effective method for promoting bioactivity in a bioinert, synthetic PEG-based adhesive while simultaneously enhancing its mechanical and adhesive properties. PMID:25222290

  1. Effect of Polyethylene Glycol on the Formation of Magnetic Nanoparticles Synthesized by Magnetospirillum magnetotacticum MS-1.

    Directory of Open Access Journals (Sweden)

    Hirokazu Shimoshige

    Full Text Available Magnetotactic bacteria (MTB synthesize intracellular magnetic nanocrystals called magnetosomes, which are composed of either magnetite (Fe3O4 or greigite (Fe3S4 and covered with lipid membranes. The production of magnetosomes is achieved by the biomineralization process with strict control over the formation of magnetosome membrane vesicles, uptake and transport of iron ions, and synthesis of mature crystals. These magnetosomes have high potential for both biotechnological and nanotechnological applications, but it is still extremely difficult to grow MTB and produce a large amount of magnetosomes under the conventional cultural conditions. Here, we investigate as a first attempt the effect of polyethylene glycol (PEG added to the culture medium on the increase in the yield of magnetosomes formed in Magnetospirillum magnetotacticum MS-1. We find that the yield of the formation of magnetosomes can be increased up to approximately 130 % by adding PEG200 to the culture medium. We also measure the magnetization of the magnetosomes and find that the magnetosomes possess soft ferromagnetic characteristics and the saturation mass magnetization is increased by 7 %.

  2. Photosynthetic, Physiological and Biochemical Responses of Tomato Plants to Polyethylene Glycol-Induced Water Deficit

    Institute of Scientific and Technical Information of China (English)

    Hatem ZGALLA(I); Kathy STEPPE; Raoul LEMEUR

    2005-01-01

    Polyethylene glycol (PEG 6000)-induced water deficit causes physiological as well as biochemical changes in plants. The present study reports on the results of such changes in hydroponically grown tomato plants (Lycopersicon esculentum Mill. cv. Nikita). Plants were subjected to moderate and severe levels of water stress (i.e. water potentials in the nutrient solution of-0.51 and -1.22 MPa, respectively).Water stress markedly affected the parameters of gas exchange. Net photosynthetic rate (Pn) decreased with the induction of water stress. Accordingly, a decrease in the transpiration rate (E) was observed. The ratio of both (Pn/E) resulted in a decrease in water use efficiency. One of the possible reasons for the reduction in Pn is structural damage to the thylakoids, which affects the photosynthetic transport of electrons. This was indicated by an increase in non-photochemical quenching and a reduction in the quantum yield of photosystem Ⅱ. Furthermore, a decrease in both leaf water potential and leaf osmotic potential was observed, which resulted in a significant osmotic adjustment during stress conditions. Analysis of the physiological responses was complemented with a study on changes in proline content. In stressed plants, a 10-fold increase in proline content was detected compared with control plants. It is clear that water stress tolerance is the result of a cumulative action of various physiological and biochemical processes, all of which were affected by PEG 6000-induced water stress.

  3. Effect of grafted polyethylene glycol (PEG) on the size, encapsulation efficiency and permeability of vesicles.

    Science.gov (United States)

    Nicholas, A R; Scott, M J; Kennedy, N I; Jones, M N

    2000-01-15

    Liposomes have been prepared by the vesicle extrusion method (VETs) from mixtures of dipalmitoylphosphatidylcholine (DPPC), phosphatidylinositol (PI) and dipalmitoylphosphatidylethanolamine with covalently linked poly(ethylene glycol) molecular mass 5000 and 2000 (DPPE-PEG 5000 and DPPE-PEG 2000) covering a range of 0-7.5 mole%. The encapsulation of D-glucose has been studied and found to be markedly dependent on the mole% DPPE-PEG. The permeability of the liposomes to D-glucose has been measured both as a function of temperature and liposome composition. The permeability coefficients for D-glucose increase with mole% DPPE-PEG 5000 and with temperature over the range 25-50 degrees C. The activation energies for glucose permeability range from 90 to 23 kJ mol(-1). The decrease in activation energy with increasing temperature is attributed to an increasing number of bilayer defects as the liposome content of PEG-grafted lipid is increased. The dependence of D-glucose encapsulation as a function of PEG-grafted lipid content is discussed in terms of the conformation of the PEG molecules on the inner surface of the bilayer. For liposomes containing DPPE-PEG 5000 the relative percentage encapsulation of glucose, assuming that the PEG surface layer excludes glucose, is comparable to that predicted from the mushroom and brush conformational models.

  4. Polyethylene glycol-g-polyvinyl alcohol grafted copolymer: reproductive toxicity study in Wistar rats.

    Science.gov (United States)

    Heuschmid, Franziska F; Schneider, Steffen; Schuster, Paul; Lauer, Birthe; van Ravenzwaay, Bennard

    2013-07-01

    Polyethylene glycol-g-polyvinyl alcohol (PEG-PVA) grafted copolymer was administered by gavage to groups of 25 male and 25 female young Wistar rats at doses of 0 (vehicle control), 100, 300, or 1000 mg/kg bw/day for one generation (F0). The study followed the treated F0 generation through mating, gestation, lactation, and weaning of the F1 generation. F1 animals were mated and followed to gestation day (GD) 15-17 at which time F2 implants were evaluated. There were no indications from the various clinical and gross pathological examinations that the oral administration of PEG-PVA grafted copolymer to the F0-parental rats produced any signs of general, reproductive, or developmental toxicity in the F0 or F1 animals or F2 implants. Based on the lack of any dose-related or biologically relevant effects on fertility, reproduction, development, and overall health of rats gavaged with PEG-PVA grafted copolymer and their progeny, the no-observed-adverse effect level (NOAEL) was determined to be the highest dose tested of 1000 mg/kg bw/day.

  5. The antithrombotic versus calcium antagonistic effects of polyethylene glycol grafted bovine pericardium.

    Science.gov (United States)

    Vasudev, S C; Chandy, T; Sharma, C P

    1999-07-01

    Cardiovascular calcification, the formation of calcium phosphate deposits in cardiovascular tissue, is a common end stage phenomenon affecting a wide variety of bioprosthesis. This study proposes a novel approach of reducing pericardial calcification and thrombosis via coupling polyethylene glycols (PEG) to glutaraldehyde treated bovine pericardium via acetal linkages. The calcification of the PEG modified tissue and the control pericardium (extracted and glutaraldehyde treated) was investigated by in vivo rat subcutaneous implantation models and by in vitro meta stable calcium phosphate solutions. Scanning electron microscopy showed that calcification primarily involved the surface of collagen fibrils and the intrafibrillar spaces. However, the grafting of pericardium with PEG-20,000 had dramatically modified the surface and subsequently inhibited the deposits of calcium. Further, the modified tissue had also reduced the platelet surface attachment. Such a reduced calcification of PEG modified tissues can be explained by decrease of free aldehyde groups, a space filling effect and therefore improved biostability and synergistic blood compatible effects of PEG after coupling to the tissues. This simple method can be a useful anticalcification treatment for implantable tissue valves.

  6. Effect of polyethylene glycol grafted onto islet capsules on prevention of splenocyte and cytokine attacks.

    Science.gov (United States)

    Lee, Dong Yun; Nam, Jong Hee; Byun, Youngro

    2004-01-01

    In the graft rejection of transplanted islets, the host's immune cells recognize the islets as antigens, which then stimulate the immune cells to begin the cytokine secretion and also the proliferation of immune cells. To prevent the recognition of islets by the immune cells, we grafted biocompatible polyethylene glycol (PEG) onto the collagen capsule of islets without incurring any changes in the morphology and function of islets. To evaluate the efficiency of PEG grafting, PEG-grafted islets were cultured with splenocytes consisting mainly of lymphocytes and macrophages. A splenocyte proliferation assessment using a BrdU incorporation assay showed that the PEG-grafted islets did not stimulate the splenocytes. In addition, the viability and microorganisms in islet cells of co-cultured PEG-grafted islets were not altered. However, in the co-culture of free islets (control) splenocytes were stimulated; they mainly secreted TNF-alpha and strongly affected the viability and structure of free islets. Furthermore, when islets were treated with the rat recombinant TNF-alpha for 7 days, the viabilities of PEG-grafted and free islets were significantly damaged, although the viability of PEG-grafted islets was higher than that of free islets by nearly three times. These results demonstrate that PEG grafted on the surface of islets could prevent the recognition of islets by splenocytes, but could not completely protect islets from cytokines.

  7. Polyethylene glycol-grafted polyethylenimine used to enhance adenovirus gene delivery.

    Science.gov (United States)

    Singarapu, Kumar; Pal, Ivy; Ramsey, Joshua D

    2013-07-01

    An improved adenoviral-based gene delivery vector was developed by complexing adenovirus (Ad) with a biocompatible, grafted copolymer PEG-g-PEI composed of polyethylene glycol (PEG) and polyethylenimine (PEI). Although an Ad-based gene vector is considered relatively safe, its native tropism, tendency to elicit an immune response, and susceptibility to inactivating antibodies makes the virus less than ideal. The goal of the current study was to determine whether Ad could be complexed with a PEG-g-PEI copolymer that would enable the virus to transduce cells lacking the Ad receptor, while avoiding the issues commonly associated with PEI. A copolymer library was synthesized using 2 kDa PEG and either linear or branched PEI (25 kDa) with a PEG to PEI grafting ratio of 10, 20, or 30. The results of the study indicate that PEG-g-PEI/Ad complexes are indeed able to transduce CAR-negative NIH 3T3 cells. The results also demonstrate that the PEG-g-PEI/Ad complexes are less toxic, less hemolytic, and more appropriately sized than PEI/Ad complexes.

  8. Endocytosis of PEGylated nanoparticles accompanied by structural and free energy changes of the grafted polyethylene glycol.

    Science.gov (United States)

    Li, Ying; Kröger, Martin; Liu, Wing Kam

    2014-10-01

    Nanoparticles (NPs) are in use to efficiently deliver drug molecules into diseased cells. The surfaces of NPs are usually grafted with polyethylene glycol (PEG) polymers, during so-called PEGylation, to improve water solubility, avoid aggregation, and prevent opsonization during blood circulation. The interplay between grafting density σp and grafted PEG polymerization degree N makes cellular uptake of PEGylated NPs distinct from that of bare NPs. To understand the role played by grafted PEG polymers, we study the endocytosis of 8 nm sized PEGylated NPs with different σp and N through large scale dissipative particle dynamics (DPD) simulations. The free energy change Fpolymer of grafted PEG polymers, before and after endocytosis, is identified to have an effect which is comparable to, or even larger than, the bending energy of the membrane during endocytosis. Based on self-consistent field theory Fpolymer is found to be dependent on both σp and N. By incorporating Fpolymer, the critical ligand-receptor binding strength for PEGylated NPs to be internalized can be correctly predicted by a simple analytical equation. Without considering Fpolymer, it turns out impossible to predict whether the PEGylated NPs will be delivered into the diseased cells. These simulation results and theoretical analysis not only provide new insights into the endocytosis process of PEGylated NPs, but also shed light on the underlying physical mechanisms, which can be utilized for designing efficient PEGylated NP-based therapeutic carriers with improved cellular targeting and uptake.

  9. [Effect of polyethylene glycol-lipid derivatives on the stability of grafted liposomes].

    Science.gov (United States)

    Xu, Yang; Shi, Li; Deng, Yi-hui

    2011-10-01

    It is reported that polyethylene glycol-lipid (PEG-lipid) derivatives increase liposomes stability, prolong the blood circulation of liposomes, enhance their tumor-targeting efficiency, and improve drug efficacy. Therefore, it is of great importance to investigate the influence of modified PEG-lipid derivatives on the physical, chemical, and biological characteristics of liposomes for the promotion of dealing with the existed problems, such as the accelerated blood clearance (ABC) phenomenon when repeated intravous injection at a certain time-interval, and developing novel targeted pharmaceutical preparations. In this review, the effects of modified PEG-lipid derivatives were summarized in many aspects. It indicats that the chemical bonds (amide, ether, ester, and disulfide) between PEG and lipid, as well as the species of lipids, such as the commonly used phosphatidylethanolamine, cholesterol, and diacylglycerol have substantial effects on the grafted liposomes stability in vitro and in vivo. Besides, the properties of lipids (the fatty acid chain length and saturation) and the groups (methoxy, carboxylic and amino) at the distal ends of the PEG chains were also considered to be important factors. In the end, the influence of the average molecular weight of PEG and the molar ratio of PEG-lipid derivatives in the total lipid were further focused.

  10. Polyethylene glycol-polyvinyl alcohol grafted copolymer: study of the bioavailability after oral administration to rats.

    Science.gov (United States)

    Heuschmid, Franziska F; Schuster, Paul; Lauer, Birthe; Fabian, Eric; Leibold, Edgar; van Ravenzwaay, Bennard

    2013-07-01

    The absorption, urinary excretion, and the biliary excretion of a single oral dose of 10 or 1000 mg/kg bw of (14)C-polyethylene glycol-polyvinyl alcohol (PEG-PVA) grafted copolymer were studied in adult male and female rats. In a balance/excretion experiment, the total excretion of ingested radioactivity was determined over a period of 168 h and residual radioactivity was detected in selected tissues and the carcass. In a biliary excretion experiment, excretion of radioactivity via the bile duct was determined over a period of 48 h after administration of the substance to cannulated rats. Most, if not all, of the radioactivity (>100%) was excreted within 48 h via the feces regardless of sex or dose. Urinary excretion was very limited: 0.45-0.50% of dose at the low dose and 0.22-0.27% of dose at the high dose. At both dose levels, residual radioactivity in the carcass and all organs and tissues after 168 h was ≤ 0.02% of dose. Biliary excretion was 0.01-0.02% of dose. Based on these findings, the bioavailability of PEG-PVA grafted copolymer was determined to be <1% demonstrating that absorption was virtually negligible following a single oral administration to male and female rats.

  11. Polyethylene glycol acrylate-grafted polysulphone membrane for artificial lungs: plasma modification and haemocompatibility improvement.

    Science.gov (United States)

    Wang, Weiping; Huang, Xin; Yin, Haiyan; Fan, Wenling; Zhang, Tao; Li, Lei; Mao, Chun

    2015-12-14

    In this study, polyethylene glycol acrylate (PEGA) was introduced onto the surface of polysulphone (PSF) membrane to prepare PSF-PEGA membranes through low-temperature plasma technology for haemocompatibility improvement of artificial lungs. The effects of plasma power, PEGA solution concentration and dipcoating temperature on surface modification were systematically investigated. Results of Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy and PEGA grafting degree confirmed that PEGA was successfully grafted onto the PSF membranes. Contact angle values showed that the hydrophilicity of the PSF-PEGA membrane surface increased by 21.5%. The results of the protein adsorption, platelet adhesion and coagulation tests further showed the excellent haemocompatibility of the modified membrane. Gas exchange tests also revealed that at a porcine blood flow rate of 5 l min(-1), O2 and CO2 exchange rates through the PSF-PEGA membrane were 198.6 and 170.9 ml min(-1), respectively; approximately this is the gas exchange capacity of commercial respiratory assistance devices.

  12. Subchronic toxicity of polyethylene glycol-g-polyvinyl alcohol grafted copolymer.

    Science.gov (United States)

    Heuschmid, Franziska F; Schuster, Paul; Lauer, Birthe; Buesen, Roland; Mellert, Werner; Groeters, Sibylle; van Ravenzwaay, Bennard

    2013-07-01

    The safety of polyethylene glycol-g-polyvinyl alcohol (PEG-PVA) grafted copolymer was evaluated in a 13-week oral toxicity study in rats and in a 9-month oral toxicity study in dogs. Wistar rats were administered 600, 3000, or 15,000 ppm PEG-PVA grafted copolymer in their drinking water whereas beagle dogs were fed 3000, 10,000, or 30,000 ppm PEG-PVA grafted copolymer in the diet. There were no mortalities, no adverse clinical signs, no toxicologically adverse effects on body weight or body weight gain, feed consumption, hematological, clinical chemistry or urinary parameters, or histopathology in either species. In rats, no treatment-related effects were observed in the functional observational battery (FOB) or related measurements of motor activity. Increased water consumption observed in rats at the highest dose was the only test substance-induced effect noted. The no-observed-adverse-effect level (NOAEL) was the highest concentration tested in both species: 15,000 ppm in rats (corresponding to a daily intake of 1611 mg/kg bw for males and 2191 mg/kg bw for females) and 30,000 ppm in dogs (corresponding to a mean daily intake of 783 mg/kg bw for males and 811 mg/kg bw for females).

  13. Developmental toxicity of polyethylene glycol-g-polyvinyl alcohol grafted copolymer in rats and rabbits.

    Science.gov (United States)

    Heuschmid, Franziska F; Schneider, Steffen; Schuster, Paul; Lauer, Birthe; van Ravenzwaay, Bennard

    2013-07-01

    Polyethylene glycol-g-polyvinyl alcohol (PEG-PVA) grafted copolymer was evaluated in developmental toxicity studies with Wistar rats and Himalayan rabbits. Pregnant Wistar rats were gavaged with 0 (vehicle control), 100, 300, or 1000 mg PEG-PVA grafted copolymer/kg bw/day from gestation day (GD) 6-15. Pregnant Himalayan rabbits received the same treatment from GD 6 to 19. On GD 20 and 29 for rats and rabbits, respectively, the animals were euthanized and were examined grossly. For each dam, corpora lutea were counted and number and distribution of implantation sites were determined. The fetuses were removed, sexed, weighed, and evaluated for any external, soft tissue, and skeletal findings. No significant findings were found that could be attributed to administration of PEG-PVA grafted copolymer. Under the conditions of these studies, the no-observed-adverse-effect level (NOAEL) for maternal and developmental toxicity in both species was the highest dose tested of 1000 mg/kg bw/day.

  14. Surface Modification of Asymmetric Polysulfone/Polyethylene Glycol Membranes by DC Ar-Glow Discharge Plasma

    Directory of Open Access Journals (Sweden)

    Chalad Yuenyao

    2016-01-01

    Full Text Available Polysulfone/polyethylene glycol (PSF/PEG membranes were prepared by dry/wet phase inversion method. Effects of direct current glow discharge plasma using argon as working gas on morphological structures and gas separation properties of membranes were studied. Alteration of membrane characteristics were analyzed by various techniques like contact angle, scanning electron microscope, Fourier transform infrared spectroscopy, and dynamic mechanical thermal analysis. Gas separation properties were measured in terms of permeation and ideal O2/N2 selectivity. Results showed that hydrophilic and gas separation properties of PSF/PEG membranes increased by plasma surface modification. It was also shown that the dosage of PEG and plasma treatment affected the morphological structures and mechanical and gas separation properties. The macro voids and transmembrane structure disappeared with a little amount of PEG dosage. Pore size and mechanical strength tend to decrease with increasing PEG dosage up to 10 wt%. Glass transition temperature (Tg receded from 201.8 to 143.7°C for pure PSF and PSF/PEG with PEG dosage of 10 wt%. O2 and N2 gases permeation through the 10-minute plasma treated membranes tend to increase. However, the permeation strongly dispersed when treatment time was more extended.

  15. Patterned Array of Poly(ethylene glycol Silane Monolayer for Label-Free Detection of Dengue

    Directory of Open Access Journals (Sweden)

    Nor Zida Rosly

    2016-08-01

    Full Text Available In the present study, the construction of arrays on silicon for naked-eye detection of DNA dengue was demonstrated. The array was created by exposing a polyethylene glycol (PEG silane monolayer to 254 nm ultraviolet (UV light through a photomask. Formation of the PEG silane monolayer and photomodifed surface properties was thoroughly characterized by using atomic force microscopy (AFM, X-ray photoelectron spectroscopy (XPS, and contact angle measurements. The results of XPS confirmed that irradiation of ultraviolet (UV light generates an aldehyde functional group that offers conjugation sites of amino DNA probe for detection of a specific dengue virus target DNA. Employing a gold enhancement process after inducing the electrostatic interaction between positively charged gold nanoparticles and the negatively charged target DNA hybridized to the DNA capture probe allowed to visualize the array with naked eye. The developed arrays demonstrated excellent performance in diagnosis of dengue with a detection limit as low as 10 pM. The selectivity of DNA arrays was also examined using a single base mismatch and noncomplementary target DNA.

  16. Surface modification of nanoporous alumina surfaces with poly(ethylene glycol).

    Science.gov (United States)

    Popat, Ketul C; Mor, Gopal; Grimes, Craig A; Desai, Tejal A

    2004-09-14

    Nanoporous alumina surfaces have a variety of applications in biosensors, biofiltration, and targeted drug delivery. However, the fabrication route to create these nanopores in alumina results in surface defects in the crystal lattice. This results in inherent charge on the porous surface causing biofouling, that is, nonspecific adsorption of biomolecules. Poly(ethylene glycol) (PEG) is known to form biocompatible nonfouling films on silicon surfaces. However, its application to alumina surfaces is very limited and has not been well investigated. In this study, we have covalently attached PEG to nanoporous alumina surfaces to improve their nonfouling properties. A PEG-silane coupling technique was used to modify the surface. Different concentrations of PEG for different immobilization times were used to form PEG films of various grafting densities. X-ray photoelectron spectroscopy (XPS) was used to verify the presence of PEG moieties on the alumina surface. High-resolution C1s spectra show that with an increase in concentration and immobilization time, the grafting density of PEG also increases. Further, a standard overlayer model was used to calculate the thickness of PEG films formed using the XPS intensities of the Al2p peaks. The films formed by this technique are less than 2.5 nm thick, suggesting that such films will not clog the pores which are in the range of 70-80 nm.

  17. Poly(ethylene glycol) monolayer formation and stability on gold and silicon nitride substrates.

    Science.gov (United States)

    Cerruti, Marta; Fissolo, Stefano; Carraro, Carlo; Ricciardi, Carlo; Majumdar, Arun; Maboudian, Roya

    2008-10-07

    Poly(ethylene glycol) (PEG) self-assembled monolayers (SAMs) are extensively used to modify substrates to prevent nonspecific protein adsorption and to increase hydrophilicity. X-ray photoelectron spectroscopy analysis, complemented by water contact angle measurements, is employed to investigate the formation and stability upon aging and heating of PEG monolayers formed on gold and silicon nitride substrates. In particular, thiolated PEG monolayers on gold, with and without the addition of an undecylic spacer chain, and PEG monolayers formed with oxysilane precursors on silicon nitride have been probed. It is found that PEG-thiol SAMs are degraded after less than two weeks of exposure to air and when heated at temperatures as low as 120 degrees C. On the contrary, PEG-silane SAMs are stable for more than two weeks, and fewer molecules are desorbed even after two months of aging, compared to those desorbed in two weeks from the PEG-thiol SAMs. A strongly bound hydration layer is found on PEG-silane SAMs aged for two months. Heating PEG-silane SAMs to temperatures as high as 160 degrees C improves the quality of the monolayer, desorbing weakly bound contaminants. The differences in stability between PEG-thiol SAMs and PEG-silane SAMs are ascribed to the different types of bonding to the surface and to the fact that the thiol-Au bond can be easily oxidized, thus causing desorption of PEG molecules from the surface.

  18. Nanostructured antifouling poly(ethylene glycol) films for silicon-based microsystems.

    Science.gov (United States)

    Sharma, Sadhana; Desai, Tejal A

    2005-02-01

    The creation of antifouling surfaces is one of the major prerequisites for silicon-based micro-electrical-mechanical systems for biomedical and analytical applications (known as BioMEMS). Poly(ethylene glycol) (PEG), a water-soluble, nontoxic, and nonimmunogenic polymer has the unique ability to reduce nonspecific protein adsorption and cell adhesion and, therefore, is generally coupled with a wide variety of surfaces to improve their biocompatibility. To this end, we have analyzed PEG thin films of various grafting densities (i.e., number of PEG chains per unit area) coupled to silicon using a single-step PEG-silane coupling reaction scheme using variable-angle ellipsometry. Initial PEG concentration and coupling time were varied to attain different grafting densities. These data were theoretically analyzed to understand the phenomenon of PEG film formation. Furthermore, all the PEG films were evaluated for their ability to control biofouling using albumin and fibrinogen as the model proteins. PEG thin films formed by using higher PEG concentrations ( > or = 10 mM PEG) or coupling time ( > or = 1 h) demonstrated enhanced protein fouling resistance behavior. This analysis is expected to be useful to form PEG films of desired grafting density on silicon substrates for appropriate application.

  19. Poly(ethylene glycol) (PEG) conjugated arginine deiminase: effects of PEG formulations on its pharmacological properties.

    Science.gov (United States)

    Holtsberg, Frederick W; Ensor, Charles Mark; Steiner, Marion R; Bomalaski, John S; Clark, Mike A

    2002-04-23

    Some tumors, such as melanomas and hepatocellular carcinomas, have a unique nutritional requirement for arginine. Thus, enzymatic degradation of extracellular arginine is one possible means for inhibiting these tumors. Arginine deiminase is an arginine degrading enzyme (ADI) that has been studied as an anti-cancer enzyme. However, ADI has a short serum half-life and, as a microbial enzyme, is highly immunogenic. Formulation of other therapeutic proteins with poly(ethylene glycol) (PEG) has overcome these problems. Here, ADI-PEGs were synthesized using PEGs of varying size, structure (linear or branched chain) and linker chemistries. All ADI-PEGs retained approximately 50% of enzyme activity when PEG was covalently attached to approximately 40% of the primary amines irrespective of the PEG molecular weight or attachment chemistry used. However, it was observed that, as the PEG size increases to 20 kDa, there was a corresponding increase in the pharmacokinetic (pK) and pharmacodynamic (pD) properties of the formulation. Variation in PEG linker or structure, or the use of PEGs >20,000 mw, did not affect the pK or pD. As has been shown with other therapeutic proteins, repeated injection of ADI-PEG into experimental animals resulted in significantly lower titers of antibodies against this protein than unmodified ADI. These data suggest that formulation of ADI with PEG of 20,000 mw results is the optimal method for formulating this promising therapeutic agent.

  20. Preparation and investigation of mefenamic acid – polyethylene glycol – sucrose ester solid dispersions

    Directory of Open Access Journals (Sweden)

    Fülöp Ibolya

    2015-12-01

    Full Text Available Mefenamic acid (MA is a widely used non-steroidal antiinflammatory (NSAID drug. The adverse effects typical of NSAIDs are also present in the case of MA, partly due to its low water solubility. The aim of this study was to increase the water solubility of MA in order to influence its absorption and bioavailability. Solid dispersions of MA were prepared by the melting method using polyethylene glycol 6000 and different types (laurate, D-1216; palmitate, P-1670; stearate, S-1670 and amounts of sucrose esters as carriers. The X-ray diffraction results show that MA crystals were not present in the products. Dissolution tests carried out in artificial intestinal juice showed that the product containing 10 % D-1216 increased water solubility about 3 times. The apparent permeability coefficient of MA across human Caco-2 intestinal epithelial cell layers was high and, despite the difference in solubility, there was no further increase in drug penetration in the presence of the applied additives.

  1. Investigation and prediction of protein precipitation by polyethylene glycol using quantitative structure-activity relationship models.

    Science.gov (United States)

    Hämmerling, Frank; Ladd Effio, Christopher; Andris, Sebastian; Kittelmann, Jörg; Hubbuch, Jürgen

    2017-01-10

    Precipitation of proteins is considered to be an effective purification method for proteins and has proven its potential to replace costly chromatography processes. Besides salts and polyelectrolytes, polymers, such as polyethylene glycol (PEG), are commonly used for precipitation applications under mild conditions. Process development, however, for protein precipitation steps still is based mainly on heuristic approaches and high-throughput experimentation due to a lack of understanding of the underlying mechanisms. In this work we apply quantitative structure-activity relationships (QSARs) to model two parameters, the discontinuity point m* and the β-value, that describe the complete precipitation curve of a protein under defined conditions. The generated QSAR models are sensitive to the protein type, pH, and ionic strength. It was found that the discontinuity point m* is mainly dependent on protein molecular structure properties and electrostatic surface properties, whereas the β-value is influenced by the variance in electrostatics and hydrophobicity on the protein surface. The models for m* and the β-value exhibit a good correlation between observed and predicted data with a coefficient of determination of R(2)≥0.90 and, hence, are able to accurately predict precipitation curves for proteins. The predictive capabilities were demonstrated for a set of combinations of protein type, pH, and ionic strength not included in the generation of the models and good agreement between predicted and experimental data was achieved.

  2. Preparation and characterization of a microencapsulated polyethylene glycol cross-linked polyhemoglobin.

    Science.gov (United States)

    Knirsch, Marcos C; Dell'Anno, Filippo; Chicoma, Dennis; Stephano, Marco Antonio; Bou-Chacra, Nádia A; Palombo, Domenico; Converti, Attilio; Polakiewicz, Bronislaw

    2015-11-01

    Many complications are associated to the therapeutic use of blood, among which are not only transfusion adverse events but also other issues such as lack of donors and high costs for collecting, testing, preserving, and distributing blood packages. Therefore, a clinically viable "blood substitute" is considered the holy grail of traumatology and may greatly benefit medicine. One of the most successful approaches to date is conjugating hemoglobin with polyethylene glycol (PEG). This conjugation aims mainly at overcoming free cell hemoglobin toxicity, which makes its use as oxygen carrier in pure form unfeasible. To improve PEG-hemoglobin conjugates feasibility, we propose applying dual functional PEG cross-linking hemoglobin molecules encapsulated by a protein carrier. The new oxygen carrier showed mean values of the hydrodynamic diameter, dispersity, and zeta potential of 1370 nm, 0.029 and -36 mV, respectively, evidencing the successful synthesis of PEG bis(N-succinimidyl succinate) and polyhemoglobin as well as the structuring of protein carrier.

  3. Short chain polyethylene glycols unusually assist thermal unfolding of human serum albumin.

    Science.gov (United States)

    Samanta, Nirnay; Mahanta, Debasish Das; Hazra, Soumitra; Kumar, Gopinatha Suresh; Mitra, Rajib Kumar

    2014-09-01

    In the present study we have investigated the thermal stability of the globular transport protein human serum albumin (HSA), in the presence of two small chain polyethylene glycols (namely PEG 200 and PEG 400). Both near- and far-UV circular dichroism (CD) study reveal that addition of PEG moderately increases the α-helical content of the protein without abruptly changing its tertiary structure. The hydration structure at the protein surface experiences a notable change at 30% PEG (v/v) concentration as evidenced from compressibility and dynamic light scattering (DLS) measurements. Thermal denaturation of HSA in the presence of PEG has been studied by CD and fluorescence spectroscopy using the intrinsic fluorophore tryptophan and it has been found that addition of PEG makes the protein more prone towards unfolding, which is in contrary to what has been observed in case of larger molecular weight polymers. The energetics of the thermal unfolding process has been obtained using differential scanning calorimetry (DSC) measurements. Our study concludes that both the indirect excluded volume principle as well as interaction of the polymer at the protein surface is responsible for the observed change of the unfolding process.

  4. Anaphylaxis to Polyethylene Glycol (Colyte®) in a Patient with Diverticulitis.

    Science.gov (United States)

    Lee, So Hee; Hwang, Sun Hyuk; Park, Jin Soo; Park, Hae Sim; Shin, Yoo Seob

    2016-10-01

    Polyethylene glycols (PEGs) are believed to be chemically inert agents, but larger PEG polymers could have immunogenicity. A 39-year-old man was referred to emergency room for loss of consciousness and dyspnea after taking of PEG-3350 (Colyte®). In laboratory findings, the initial serum tryptase level was increased to 91.9 mg/L (normal range: 0.00-11.40 mg/L) without any other laboratory abnormalities. The intradermal test with 10 mg/mL Colyte® showed a 5 × 5 mm wheal, but basophil activation and histamine releasability tests were negative. PEG-3350 is widely used as an osmotic laxative due to its lack of absorption from the gastrointestinal tract. However, the loss of mucosal integrity at gastrointestinal membrane such as diverticulitis may be a predisposing factor for anaphylaxis to Colyte®. We report a case of anaphylaxis induced by the ingestion of PEG-3350 in a patient with diverticulitis which might be a risk factor of anaphylaxis.

  5. Stabilization of Chromobacterium viscosum Lipase (CVL) Against Ultrasound Inactivation by the Pretreatment with Polyethylene Glycol (PEG).

    Science.gov (United States)

    Talukder, Md Mahabubur Rahman; Shiong, Simon Choo Sze

    2015-12-01

    Although ultrasound has been used to accelerate many enzymatic reactions, the low stability of enzymes in such a system still remains a critical issue, limiting its industrial application. Here, we have reported that polyethylene glycol (PEG) pretreatment stabilized Chromobacterium viscosum lipase (CVL) in ultrasound-assisted water-isooctane emulsion. PEGs of different molecular weights and concentrations were used to pretreat CVL, and the pretreated lipase activities for olive oil hydrolysis were investigated at different ultrasonic powers. The best result was attained with PEG400 at 100 mg/ml for a lipase concentration of 0.02 mg/ml and an ultrasonic power of 106 W. The half-life time of PEG400-treated lipase at 106 W was 54 min, a 27-fold higher than that attained using untreated lipase. Circular dichroism (CD) spectra suggested that PEG increased the rigidity of CVL structure, which favored the lipase stability against ultrasound inactivation. These results have important implications for the exploitation of ultrasound in biocatalytic process.

  6. Adsorption Capacity and Mechanism of Expanded Graphite for Polyethylene Glycol and Oils

    Directory of Open Access Journals (Sweden)

    Xiu-Yan Pang

    2010-01-01

    Full Text Available Expanded graphite (EG shows higher adsorption capacity for oils such as salad oil and SD300 oil than polyethylene glycol (PEG with different MW (4000, 10000, 20000. To illustrate their different adsorption mechanism, adsorption capacities of EG for these pollutants are firstly detected. And then stepwise adsorption for oils is carried out with EG which has been saturated first by PEG with different MW. Then difference between stepwise adsorbance of oil is checked with deviation analysis. Scanning electronic microscopy (SEM analysis is used to show structure difference of EG adsorbed different adsorbates. It is testified adsorption isotherms of PEG are all type I, PEG molecules lay flat on EG surface and equilibrium adsorbance decrease with the increase of PEG MW. Adsorbance for SD 300 oil and salad oil can reach 131.3 g/g and 127.8 g/g respectively. Deviation analysis for stepwise adsorbance of oil shows no statistical significance. EG saturated firstly by PEG, still has an average adsorption capacity of 98 g/g for SD300 oil and 85 g/g for salad oil and it does not change with the initial PEG concentration. SEM photos illustrate the adsorption of oil on EG is mainly filling. In the adsorption of PEG water solution, there is severe breakage of the V-type pore and shrinkage of the particle.

  7. Efficiency of SPIONs functionalized with polyethylene glycol bis(amine) for heavy metal removal

    Science.gov (United States)

    Wanna, Yongyuth; Chindaduang, Anon; Tumcharern, Gamolwan; Phromyothin, Darinee; Porntheerapat, Supanit; Nukeaw, Jiti; Hofmann, Heirich; Pratontep, Sirapat

    2016-09-01

    Hybrid magnetic nanoparticles based on poly(methylmethacrylate) (PMMA) and super-paramagnetic iron oxide nanopaticles (SPIONs) with selective surface modification has been developed for heavy metal removal by applying external magnetic fields. The nanoparticles were prepared by the emulsion polymerization technique in an aqueous suspension of SPIONs. The hydrolysis of carboxyl functional group was then applied for grafting polyethylene glycol bis(amine)(PEG-bis(amine)) onto the PMMA-coated SPIONs. The morphology, the chemical structure and the magnetic properties of the grafted nanoparticles were investigated. The efficiency of the hybrid nanoparticles for heavy metal removal were conducted on Pb(II), Hg(II), Cu(II) and Co(II) in aqueous solutions.The metal concentration in the solutions after separation by the hybrid nanoparticles was determined by inductively coupled plasma optical emission spectrometer (ICP-OES). The results show the heavy metal uptake ratios of 0.08, 0.04, 0.03, and 0.01 mM per gramme of the grafted SPIONs for Pb(II), Hg(II), Cu(II), and Co(II), respectively. A competitive removal of Cu(II), Pb(II), Co(II) and Hg(II) ions in mixed metal salt solutions has also been studied.The heavy metal removal efficiency of the hybrid nanoparitcles was found to depend on the cation radius, in accordance with capture of metal ions by the amine group.

  8. Inhibition of Cariogenic Plaque Formation on Root Surface with Polydopamine-Induced-Polyethylene Glycol Coating

    Directory of Open Access Journals (Sweden)

    May Lei Mei

    2016-05-01

    Full Text Available Root caries prevention has been a challenge for clinicians due to its special anatomical location, which favors the accumulation of dental plaque. Researchers are looking for anti-biofouling material to inhibit bacterial growth on exposed root surfaces. This study aimed to develop polydopamine-induced-polyethylene glycol (PEG and to study its anti-biofouling effect against a multi-species cariogenic biofilm on the root dentine surface. Hydroxyapatite disks and human dentine blocks were divided into four groups for experiments. They received polydopamine-induced-PEG, PEG, polydopamine, or water application. Contact angle, quartz crystal microbalance, and Fourier transform infrared spectroscopy were used to study the wetting property, surface affinity, and an infrared spectrum; the results indicated that PEG was induced by polydopamine onto a hydroxyapatite disk. Salivary mucin absorption on hydroxyapatite disks with polydopamine-induced-PEG was confirmed using spectrophotometry. The growth of a multi-species cariogenic biofilm on dentine blocks with polydopamine-induced-PEG was assessed and monitored by colony-forming units, confocal laser scanning microscopy, and scanning electron microscopy. The results showed that dentine with polydopamine-induced-PEG had fewer bacteria than other groups. In conclusion, a novel polydopamine-induced-PEG coating was developed. Its anti-biofouling effect inhibited salivary mucin absorption and cariogenic biofilm formation on dentine surface and thus may be used for the prevention of root dentine caries.

  9. Entrapping quercetin in silica/polyethylene glycol hybrid materials: Chemical characterization and biocompatibility.

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Nocera, Paola; Piccolella, Simona; Pacifico, Severina

    2016-11-01

    Sol-gel synthesis was exploited to entrap quercetin, a natural occurring antioxidant polyphenol, in silica-based hybrid materials, which differed in their polyethylene glycol (PEG) content (6, 12, 24 and 50wt%). The materials obtained, whose nano-composite nature was ascertained by Scanning Electron Microscopy (SEM), were chemically characterized by Fourier Transform InfraRed (FT-IR) and UV-Vis spectroscopies. The results prove that a reaction between the polymer and the drug occurred. Bioactivity tests showed their ability to induce hydroxyapatite nucleation on the sample surfaces. The direct contact method was applied to screen the cytotoxicity of the synthetized materials towards fibroblast NIH 3T3 cells, commonly used for in vitro biocompatibility studies, and three nervous system cell lines (neuroblastoma SH-SY5Y, glioma U251, and pheochromocytoma PC12 cell lines), adopted as models in oxidative stress related studies. Using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay NIH 3T3 proliferation was assessed and the morphology was not compromised by direct exposure to the materials. Analogously, PC-12, and U-251 cell lines were not affected by new materials. SH-SY5Y appeared to be the most sensitive cell line with cytotoxic effects of 20-35%. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Subunit Stabilization and Polyethylene Glycolation of Cocaine Esterase Improves In Vivo Residence Time

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, Diwahar; Collins, Gregory T.; Nance, Mark R.; Nichols, Joseph; Edwald, Elin; Chan, Jimmy; Ko, Mei-Chuan; Woods, James H.; Tesmer, John J.G.; Sunahara, Roger K. (Michigan)

    2012-03-15

    No small-molecule therapeutic is available to treat cocaine addiction, but enzyme-based therapy to accelerate cocaine hydrolysis in serum has gained momentum. Bacterial cocaine esterase (CocE) is the fastest known native enzyme that hydrolyzes cocaine. However, its lability at 37 C has limited its therapeutic potential. Cross-linking subunits through disulfide bridging is commonly used to stabilize multimeric enzymes. Herein we use structural methods to guide the introduction of two cysteine residues within dimer interface of CocE to facilitate intermolecular disulfide bond formation. The disulfide-crosslinked enzyme displays improved thermostability, particularly when combined with previously described mutations that enhance stability (T172R-G173Q). The newly modified enzyme yielded an extremely stable form of CocE (CCRQ-CocE) that retained greater than 90% of its activity after 41 days at 37 C, representing an improvement of more than 4700-fold over the wild-type enzyme. CCRQ-CocE could also be modified by polyethylene glycol (PEG) polymers, which improved its in vivo residence time from 24 to 72 h, as measured by a cocaine lethality assay, by self-administration in rodents, and by measurement of inhibition of cocaine-induced cardiovascular effects in rhesus monkeys. PEG-CCRQ elicited negligible immune response in rodents. Subunit stabilization and PEGylation has thus produced a potential protein therapeutic with markedly higher stability both in vitro and in vivo.

  11. Effect of poly(ethylene glycol) length on the in vivo behavior of coated quantum dots.

    Science.gov (United States)

    Daou, T Jean; Li, Liang; Reiss, Peter; Josserand, Véronique; Texier, Isabelle

    2009-03-03

    The use of nanoparticles, either for the delivery of drugs or for imaging contrast agents, or a combination of both (theranostics), is very appealing in biological and biomedical research. The design of high-quality NIR-emitting quantum dots (QDs), with outstanding optical properties in comparison to that of organic dyes, should lead to novel contrast agents with improved performance for optical and multimodal imaging. Moreover, these nanocrystals could also be used for exploring therapeutic applications, such as drug delivery or phototherapy. In this article, we report the coating of commercial ITK705-amino QDs with methoxy-terminated poly(ethylene glycol) (PEG) of different chain lengths. Homogeneous QD solutions that are stable over extended periods of time were prepared. The impact of the particle coating on their in vivo fate after tail i.v. injection was studied by fluorescence imaging. The speed of the first pass extraction of the coated QDs toward the liver decreased with the PEG length, whereas the hydrodynamic diameter of the particles was increased.

  12. Photosensitive diazotized poly(ethylene glycol) covalent capillary coatings for analysis of proteins by capillary electrophoresis.

    Science.gov (United States)

    Yu, Bing; Chen, Xin; Cong, Hailin; Shu, Xi; Peng, Qiaohong

    2016-09-01

    A new method for the fabrication of covalently cross-linked capillary coatings of poly(ethylene glycol) (PEG) is described using diazotized PEG (diazo-PEG) as a new photosensitive coating agent. The film of diazo-PEG depends on ionic bonding and was first prepared on the inner surface of capillary by self-assembly, and ionic bonding was converted into covalent bonding after reaction of ultraviolet light with diazo groups through unique photochemical reaction. The covalently bonded coating impedance adsorption of protein on the central surface of capillary and hence the four proteins ribonuclease A, cytochrome c, bovine serum albumin, and lysosome can be baseline separated by using capillary electrophoresis (CE). The covalently cross-linked diazo-PEG capillary column coatings not only improved the CE separation performance for proteins compared to non-covalently cross-linked coatings or bare capillary but also showed a remarkable chemical solidity and repeatability. Because photosensitive diazo-PEG took the place of the highly noxious and silane moisture-sensitive coating reagents in the fabrication of covalent coating, this technique shows the advantage of being environment-friendly and having a high efficiency for CE to make the covalently bonded capillaries.

  13. Severe symptomatic hyponatremia associated with the use of polyethylene glycol-based bowel preparation

    Directory of Open Access Journals (Sweden)

    Navira Samad

    2017-02-01

    Full Text Available Colonoscopy is a useful tool in modern medicine and is increasingly employed for both diagnostic and treatment reasons. However, its effectiveness is highly reliant on the quality of bowel cleansing. Among different bowel-cleansing agents available, PEG (polyethylene glycol is considered to be the safest cleansing agent, especially in relation to fluid and electrolyte problems. We present here a case of severe symptomatic hyponatremia that developed after the use of PEG for an elective colonoscopy. This case highlights that despite the use of PEG-based preparations, life-threatening fluid and electrolyte disturbances can still occur in patients with risk factors, such as old age, use of thiazide diuretics and SSRIs, chronic kidney disease, heart failure and a history of electrolyte problems. These patients should be closely monitored when undertaking bowel cleansing and should receive prompt care in the event of complications, to avoid permanent neurological sequelae and death. Rapid correction of sodium levels in patients requiring treatment of hyponatremia should be avoided to prevent complications such as osmotic demyelination syndrome.

  14. Sensitivity of PEGylated interferon detection by anti-polyethylene glycol (PEG) antibodies depends on PEG length.

    Science.gov (United States)

    Cheng, Ta-Chun; Chuang, Kuo-Hsiang; Chen, Michael; Wang, Hsin-Ell; Tzou, Shey-Cherng; Su, Yu-Cheng; Chuang, Chih-Hung; Kao, Chien-Han; Chen, Bing-Mae; Chang, Long-Sen; Roffler, Steve R; Cheng, Tian-Lu

    2013-08-21

    Attachment of poly(ethylene glycol) to proteins can mask immune epitopes to increase serum half-life, reduce immunogenicity, and enhance in vivo biological efficacy. However, PEGylation mediated epitope-masking may also limit sensitivity and accuracy of traditional ELISA. We previously described an anti-PEG-based sandwich ELISA for universal assay of PEGylated molecules. Here, we compared the quantitative assessment of PEGylated interferons by anti-PEG and traditional anti-interferon sandwich ELISA. The detection limits for PEG-Intron (12k-PEG) and Pegasys (40k-PEG) were 1.9 and 0.03 ng/mL for anti-PEG ELISA compared to 0.18 and 0.42 ng/mL for traditional anti-interferon sandwich ELISA. These results indicate that the anti-PEG sandwich ELISA was insensitive to PEGylation mediated epitope-masking and the sensitivity increased in proportion to the length of PEG. By contrast, PEG-masking interfered with detection by traditional anti-interferon sandwich ELISA. Human and mouse serum did not affect the sensitivity of anti-PEG ELISA but impeded traditional anti-interferon sandwich ELISA. The anti-PEG sandwich ELISA was comparable to anti-interferon sandwich ELISA and radioassay of 131I-Pegasys in pharmacokinetic studies in mice. The anti-PEG sandwich ELISA provides a sensitive, accurate, and convenient quantitative measurement of PEGylated protein drugs.

  15. Electron spin resonance studies of the effects of sterilization on poly(ethylene glycol) hydrogels.

    Science.gov (United States)

    Kanjickal, Deenu; Lopina, Stephanie; Evancho-Chapman, Mary Michelle; Schmidt, Steven; Inbaraj, Johnson J; Cardon, Thomas B; Lorigan, Gary A

    2009-02-01

    The effects of several sterilization procedures on a poly(ethylene glycol) (PEG) hydrogel have been examined by electron spin resonance (ESR) spectroscopy. The crosslinked polyurethanes were synthesized by reacting PEG with a tri-functional isocyanate. The free radical concentration of unsterilized, ethylene oxide (EtO), hydrogen peroxide (H(2)O(2)), and gamma sterilized hydrogels were monitored over time. Free radical presence was observed for all the treatments, unsterilized and sterilized PEG hydrogels. The unsterilized and the EtO sterilized samples elicited similar levels of free radical intensity whereas, the H(2)O(2) and gamma sterilized samples had a significantly higher free radical concentration. The spectra reveal overlapping resonances of a peroxy and a triphenylmethyl radical. The concentration of the free radicals increase for all the treatments over time except for the gamma sterilized sample. The increase is significantly higher in the H(2)O(2) sterilized sample. A tentative model is proposed to explain the reaction pathway leading to the production of the free radicals. The observed increases in the free radical concentrations of the EtO and hydrogen peroxide sterilized hydrogels over a five-month-period make it difficult to predict properties that are affected by free radical concentrations. In that light, gamma sterilization, that does not induce a change in free radical concentrations over a five month period, could be the sterilization method of choice for PEG hydrogels that could potentially be stored for undetermined periods of time prior to application.

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

    Science.gov (United States)

    Garagorri, Nerea; Fermanian, Sara; Thibault, Richard; Ambrose, Winnette McIntosh; Schein, Oliver D; Chakravarti, Shukti; Elisseeff, Jennifer

    2008-09-01

    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.

  17. Highly porous and mechanically robust polyester poly(ethylene glycol) sponges as implantable scaffolds.

    Science.gov (United States)

    Ozcelik, Berkay; Blencowe, Anton; Palmer, Jason; Ladewig, Katharina; Stevens, Geoffrey W; Abberton, Keren M; Morrison, Wayne A; Qiao, Greg G

    2014-06-01

    The development of suitable scaffolds plays a significant role in tissue engineering research. Although scaffolds with promising features have been produced via a variety of innovative methods, there are no fully synthetic tissue engineering scaffolds that possess all the desired properties in one three-dimensional construct. Herein, we report the development of novel polyester poly(ethylene glycol) (PEG) sponges that display many of the desirable scaffold characteristics. Our novel synthetic approach utilizes acidchloride/alcohol chemistry, whereby the reaction between a hydroxyl end-functionalized 4-arm PEG and sebacoyl chloride resulted in cross-linking and simultaneous hydrogen chloride gas production, which was exploited for the in situ formation of highly interconnected pores. Variation of the fabrication conditions, including the precursor volume and concentration, allowed the pore size and structure as well as the compressive properties to be tailored. The sponges were found to possess excellent elastic properties, preserving their shape even after 80% compressive strain without failure. The benign properties of the sponges were demonstrated in an in vivo subcutaneous rat model, which also revealed uniform infiltration of vascularized tissue by 8 weeks and complete degradation of the sponges by 16 weeks, with only a minimal inflammatory response being observed over the course of the experiments. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  18. Recent development of poly(ethylene glycol)-cholesterol conjugates as drug delivery systems.

    Science.gov (United States)

    He, Zhi-Yao; Chu, Bing-Yang; Wei, Xia-Wei; Li, Jiao; Edwards, Carl K; Song, Xiang-Rong; He, Gu; Xie, Yong-Mei; Wei, Yu-Quan; Qian, Zhi-Yong

    2014-07-20

    Poly(ethylene glycol)-cholesterol (PEG-Chol) conjugates are composed of "hydrophilically-flexible" PEG and "hydrophobically-rigid" Chol molecules. PEG-Chol conjugates are capable of forming micelles through molecular self-assembly and they are also used extensively for the PEGylation of drug delivery systems (DDS). The PEGylated DDS have been shown to display optimized physical stability properties in vitro and longer half-lives in vivo when compared with non-PEGylated DDS. Cell uptake studies have indicated that PEG-Chol conjugates are internalized via clathrin-independent pathways into endosomes and Golgi apparatus. Acid-labile PEG-Chol conjugates are also able to promote the content release of PEGylated DDS when triggered by dePEGylation at acidic conditions. More importantly, biodegradable PEG-Chol molecules have been shown to decrease the "accelerated blood clearance" phenomenon of PEG-DSPE. Ligands, peptides or antibodies which have been modified with PEG-Chols are oftentimes used to formulate active targeting DDS, which have been shown in many systems recently to enhance the efficacy and lower the adverse effects of drugs. Production of PEG-Chol is simple and efficient, and production costs are relatively low. In conclusion, PEG-Chol conjugates appear to be very promising multifunctional biomaterials for many uses in the biomedical sciences and pharmaceutical industries. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Interconnected macroporous poly(ethylene glycol) cryogels as a cell scaffold for cartilage tissue engineering.

    Science.gov (United States)

    Hwang, Yongsung; Sangaj, Nivedita; Varghese, Shyni

    2010-10-01

    Macroporous networks of poly(ethylene glycol) (PEG) with interconnected pores can be created by cryogelation techniques. In this study, we describe the potential application of such PEG cryogels as scaffolds for cartilage tissue engineering. Three-dimensional macroporous cryogels were evaluated for chondrocyte growth and production of cartilage-specific extracellular matrix (ECM). Seeded primary bovine chondrocytes showed homogeneous distribution throughout the cryogels. DNA content suggests continuous cell proliferation over 4 weeks of in vitro culture. Analysis of the composition of cell-secreted ECM showed a culture-time-dependent increase in the amount of glycosaminoglycan and collagen. The production of ECM by chondrocytes was confirmed using scanning electron microscopy analysis. Further histological and immunohistological analysis of the cell-laden scaffold confirmed the presence of accumulated cartilage-specific ECM within the scaffold. The interconnected macroporous network promoted diffusion of cell-secreted matrix within the cryogels. Our results indicated that interconnected macroporous PEG cryogels successfully supported attachment, viability, proliferation, and biosynthetic activity of seeded chondrocytes.

  20. Novel prodrugs of SN38 using multiarm poly(ethylene glycol) linkers.

    Science.gov (United States)

    Zhao, Hong; Rubio, Belen; Sapra, Puja; Wu, Dechun; Reddy, Prasanna; Sai, Prakash; Martinez, Anthony; Gao, Ying; Lozanguiez, Yoany; Longley, Clifford; Greenberger, Lee M; Horak, Ivan D

    2008-04-01

    CPT-11, also known as irinotecan, is a prodrug that is approved for the treatment of advanced colorectal cancer. The active metabolite of CPT-11, SN38 (7-ethyl-10-hydroxy-camptothecin), has 100- to 1000-fold more potent cytotoxic activity in tissue cell culture compared with CPT-11. However, parental administration of SN38 is not possible because of its inherently poor water solubility. It is reported here that a multiarm poly(ethylene glycol) (PEG) backbone linked to four SN38 molecules (PEG-SN38) has been successfully prepared with high drug loading and significantly improved water solubility (400- to 1000-fold increase). Three different protecting strategies have been developed in order to selectively acylate the 20-OH of SN38 to preserve its E-ring in the lactone form (the active form of SN38 with cytotoxic activities) while PEG is still attached. One chemical process has been optimized to make a large quantity of the PEG-SN38 conjugate with a high yield that can be readily adapted for scale-up production. The PEG-SN38 conjugates have shown excellent in vitro anticancer activity, with potency similar to that of native SN38, in a panel of cancer cell lines. The PEG-SN38 conjugates also have demonstrated superior anticancer activity in the MX-1 xenograft mice model compared with CPT-11. Among the four conjugates, PEG-Gly-(20)-SN38 (23) has been selected as the lead candidate for further preclinical development.

  1. Case of inappropriate ADH syndrome: hyponatremia due to polyethylene glycol bowel preparation.

    Science.gov (United States)

    Ko, Sun-Hye; Lim, Chul-Hyun; Kim, Jae-Young; Kang, Seung Hun; Baeg, Myong Ki; Oh, Hyun Jin

    2014-09-14

    Colonoscopic screening has been reported to reduce deaths from colorectal cancer. Adequate bowel preparation is essential for this and safety is an important issue in choosing the methods. Polyethylene glycol (PEG) is regarded as a safe method for cleansing, especially compared with oral sodium phosphate. Here, we present a case of hyponatremia caused by the syndrome of inappropriate antidiuretic hormone (ADH) syndrome after PEG precolonoscopic cleansing resulting in generalized tonic-clonic seizures. A 62-year-old women had ingested PEG for precolonoscopic bowel cleansing. While waiting for the colonoscopy, she developed a stuporous mentality and generalized tonic-clonic seizures, which did not correlate with brain magnetic resonance imaging. Her serum sodium level was 113 mEq per liter and laboratory analyses were consistent with inappropriate ADH syndrome. Her thyroid and adrenal functions were normal. There were no malignancies, infections, respiratory disorders or central nervous disorders and she had no history of taking either diuretics or other medications, which might have caused inappropriate ADH syndrome. She was treated with 3% hypertonic saline and showed a complete neurological recovery as her sodium levels recovered. Follow-up visits showed the patient to have a normal sodium level without neurologic deficits. This case shows that inappropriate ADH syndrome can be caused by PEG preparation, which implies that physicians have to be aware of the possible side effects of this colonic cleansing approach and mindful of the possible ensuing symptoms.

  2. Plasma-induced graft-polymerization of polyethylene glycol acrylate on polypropylene substrates

    Science.gov (United States)

    Zanini, S.; Orlandi, M.; Colombo, C.; Grimoldi, E.; Riccardi, C.

    2009-08-01

    A detailed study of argon plasma-induced graft-polymerization of polyethylene glycol acrylate (PEGA) on polypropylene (PP) substrates (membranes and films) is presented. The process consists of four steps: (a) plasma pre-activation of the PP substrates; (b) immersion in a PEGA solution; (c) argon plasma-induced graft-polymerization; (d) washing and drying of the samples. Influence of the solution and plasma parameters on the process efficiency evaluated in terms of amount of grafted polymer, coverage uniformity and substrates wettability, are investigated. The plasma-induced graft-polymerization of PEGA is then followed by sample weighting, water droplet adsorption time and contact angle measurements, attenuated total reflection infrared spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) analyses. The stability of the obtained thin films was evaluated in water and in phosphate buffer saline (PBS) at 37 °C. Results clearly indicates that plasma-induced graft-polymerization of PEGA is a practical methodology for anti-fouling surface modification of materials.

  3. Effects of the poly(ethylene glycol) hydrogel crosslinking mechanism on protein release†

    Science.gov (United States)

    Lee, Soah; Tong, Xinming

    2016-01-01

    Poly(ethylene glycol) (PEG) hydrogels are widely used to deliver therapeutic biomolecules, due to high hydrophilicity, tunable physicochemical properties, and anti-fouling properties. Although different hydrogel crosslinking mechanisms are known to result in distinct network structures, it is still unknown how these various mechanisms influence biomolecule release. Here we compared the effects of chain-growth and step-growth polymerization for hydrogel crosslinking on the efficiency of protein release and diffusivity. For chain-growth-polymerized PEG hydrogels, while decreasing PEG concentration increased both the protein release efficiency and diffusivity, it was unexpected to find out that increasing PEG molecular weight did not significantly change either parameter. In contrast, for step-growth-polymerized PEG hydrogels, both decreasing PEG concentration and increasing PEG molecular weight resulted in an increase in the protein release efficiency and diffusivity. For step-growth-polymerized hydrogels, the protein release efficiency and diffusivity were further decreased by increasing crosslink functionality (4-arm to 8-arm) of the chosen monomer. Altogether, our results demonstrate that the crosslinking mechanism has a differential effect on controlling protein release, and this study provides valuable information for the rational design of hydrogels for sophisticated drug delivery. PMID:26539660

  4. Characteristics of Hyaluronic Acid Derivative Cross-linked by Polyethylene Glycol

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Characteristic and dynamic viscosities of Hyaluronic acid ( HA ) derivative modified by polyethylene glycol (PEG) were tested with different reaction times (6 h,12 h,18 h and 24 h ) , different molar ratio of HA/PEG ( 1/10,1/5,1/3 and 1/2), different molecular weight of PEG(400,6 000 and 20 000) and mass fraction is 0.4% by Wushi Viscosimeter and L- 90 Rheometer at 25 ℃. Characteristic viscosity of HA derivative had the largest value in 12 h, which decreased with increasing of PEG molecular weight, but its aqueous dynamic viscosity increased with increment of PEG molecular weight. Meanwhile, we tested dynamic mechanic properties of HA derivative by 3ARES3 Rheometer at 25 ℃ to study viscoelastic changes and to compare change difference from viscosity to elasticity with the changes of vibration frequency between unmodified HA and HA derivative.Change from low vibrated frequency to high one of solution resulted in change from viscosity to elasticity of solution. In conclusion, as to the rheological properties, structure-modified HA derivative meets the requirement of biomnterial .

  5. Production of L-phenylacetylcarbinol by microbial transformation in polyethylene glycol-induced cloud point system.

    Science.gov (United States)

    Zhang, Wenzhi; Wang, Zhilong; Li, Wei; Zhuang, Baohua; Qi, Hanshi

    2008-02-01

    Microbial transformation of benzaldehyde into L: -phenylacetylcarbinol by whole cell Saccharomyces cerevisiae has been carried out in a novel polyethylene glycol (PEG)-induced cloud point system. The system is composed of 80 g PEG 20,000, 75 ml Triton X-100, 20 g peptone, 10 g yeast extract, 25 g glucose, 1 g MgSO(4).7H(2)O, 0.05 g CaCl(2).2H(2)O, 35 g Na(2)HPO(4).12H(2)O, and 10.7 g citric acid per liter of tap water. The microbial transformation is conducted at 0.6 ml of acetaldehyde (35% volume content), 0.9 ml of benzaldehyde, and 7 g of wet cell per 100 ml of the PEG-induced cloud point system. Under the conditions, a relatively longer-term bioactivity of whole cell microorganism in the PEG-induced cloud point system has been achieved. A fed-batch microbial transformation process with a discrete addition of glucose and substrate gets a high final product concentration of about 8 g/l.

  6. 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.

  7. Physical Characteristics of Chitosan Based Film Modified With Silica and Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    F. Widhi Mahatmanti

    2014-07-01

    Full Text Available Recently, development of film materials is focused on finding the films with high chemical and physical stabilities. Organic based material such as chitosan produces films with low physical stability, and hence addition of inorganic materials necessary. In this research, the effect of silica and polyethylene glycol (PEG addition on the properties of chitosan based films has been investigated. Precursors used to produce films included chitosan with the deacetylation degree of 83% and sodium silicate solution as the silica source. A simple synthesis in a one-pot process was carried out by mixing 1%(w of chitosan solution in 2%(v/v acetate acid and sodium silicate solution (27% SiO2 in various composition ratios and casting the solution on a glass dish. The tensile strength and percentage of elongation decrease with increasing the silica content. The tensile strength tends to decline with addition of PEG, but the elongation percentage of the film increases. Hydrophilicity of the film decreases with the addition of silica and increases with the addition of PEG. The addition of silica and PEG does not change significantly the morphology of the film and functional groups indicating the domination of physical interaction among active sites in the film components.

  8. Preparation and characterization of biodegradable polyhydroxybutyrate-co-hydroxyvalerate/polyethylene glycol-based microspheres.

    Science.gov (United States)

    Monnier, Alexandre; Rombouts, Charlotte; Kouider, Dania; About, Imad; Fessi, Hatem; Sheibat-Othman, Nida

    2016-11-20

    The in vivo effectiveness of biomolecules may be limited by their rapid diffusion in the body and short half-life time. Encapsulation of these biomolecules allows protecting them against degradation and ensuring a controlled release over time. In this work, the production of polyhydroxybutyrate-co-hydroxyvalerate/polyethylene glycol-based microspheres loaded with heparin by double emulsion-solvent evaporation is investigated. Significant improvements are achieved after blending PHB-HV microspheres with PEG. First of all, an important decrease of the initial burst effect is ensured. Moreover, lower degradation of the microspheres is observed after 30days in the release medium. Finally, the release rate could be controlled using different PEG molecular weights and concentrations. A toxic effect of PHB-HV 30% PEG 1100gmol(-1) microspheres is observed whereas PHB-HV and PHB-HV 30% PEG 10,000gmol(-1) microspheres are not toxic. These microspheres seem to be most suited for further tissue engineering applications. The effectiveness of direct PEG blending to PHB-HV is proved, limiting the use of chemical reagents for PHB-HV/PEG copolymer synthesis and steps for chemical reagents removal from the copolymer. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Polyethylene glycol-modified arachidyl chitosan-based nanoparticles for prolonged blood circulation of doxorubicin.

    Science.gov (United States)

    Termsarasab, Ubonvan; Yoon, In-Soo; Park, Ju-Hwan; Moon, Hyun Tae; Cho, Hyun-Jong; Kim, Dae-Duk

    2014-04-10

    Doxorubicin (DOX)-loaded nanoparticles based on polyethylene glycol-conjugated chitosan oligosaccharide-arachidic acid (CSOAA-PEG) were explored for potential application to leukemia therapy. PEG was conjugated with CSOAA backbone via amide bond formation and the final product was verified by (1)H NMR analysis. Using the synthesized CSOAA-PEG, nanoparticles having characteristics of a 166-nm mean diameter, positive zeta potential, and spherical shape were produced for the delivery of DOX. The mean diameter of CSOAA-PEG nanoparticles in the serum solution (50% fetal bovine serum) remained relatively constant over 72 h as compared with CSOAA nanoparticles (changes of 20.92% and 223.16%, respectively). The sustained release pattern of DOX from CSOAA-PEG nanoparticles was displayed at physiological pH, and the release rate increased under the acidic pH conditions. The cytotoxicity of the CSOAA-PEG conjugate was negligible in human leukemia cells (K562) at the concentrations tested (∼ 100 μg/ml). The uptake rate of DOX from the nanoparticles by K562 cells was higher than that from the solution. Judging from the results of pharmacokinetic studies in rats, in vivo clearance rate of DOX from the CSOAA-PEG nanoparticle group was slower than other groups, subsequently extending the circulation period. The PEGylated CSOAA-based nanoparticles could represent an effective nano-sized delivery system for DOX which has been used for the treatment of blood malignancies.

  10. OPTIMIZATION AND CHARACTERIZATION OF POLYSULFONE MEMBRANES MADE OF ZINC OXIDE, POLYETHYLENE GLYCOL AND EUGENOL AS ADDITIVES

    Directory of Open Access Journals (Sweden)

    MUHAMAD ZAINI YUNOS

    2016-07-01

    Full Text Available The aim of this study to investigate the effect of zinc oxide, polyethylene glycol (PEG and eugenol on the properties of membranes made of polysulfone (PSf. Polysulfone membranes were prepared via phase inversion method using Nmethyl-2-pyrolidone (NMP as a solvent and water as non-solvent. The membranes were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, atomic force microscopy (AFM, porosity, tensile strength, permeability, rejection and antibacterial test. The results were designed and optimized through a statistical approach using response surface methodology (RSM. The results showed that the use of zinc oxide and eugenol could improve membrane rejection and anti-bacterial property. The membrane permeability was found to increase with addition of PEG. The optimized dope formulation for maximum membrane permeability and rejection was found at 13.14 wt.% PEG 5 wt.% zinc oxide and 0.17 wt.% eugenol. The permeability and rejection obtained for actual value is 866 L m-2h-1 and 91.0% respectively, which 1 and 2% difference compared to the predicted value.

  11. Biodegradable DNA-enabled poly(ethylene glycol) hydrogels prepared by copper-free click chemistry.

    Science.gov (United States)

    Barker, Karolyn; Rastogi, Shiva K; Dominguez, Jose; Cantu, Travis; Brittain, William; Irvin, Jennifer; Betancourt, Tania

    2016-01-01

    Significant research has focused on investigating the potential of hydrogels in various applications and, in particular, in medicine. Specifically, hydrogels that are biodegradable lend promise to many therapeutic and biosensing applications. Endonucleases are critical for mechanisms of DNA repair. However, they are also known to be overexpressed in cancer and to be present in wounds with bacterial contamination. In this work, we set out to demonstrate the preparation of DNA-enabled hydrogels that could be degraded by nucleases. Specifically, hydrogels were prepared through the reaction of dibenzocyclooctyne-functionalized multi-arm poly(ethylene glycol) with azide-functionalized single-stranded DNA in aqueous solutions via copper-free click chemistry. Through the use of this method, biodegradable hydrogels were formed at room temperature in buffered saline solutions that mimic physiological conditions, avoiding possible harmful effects associated with other polymerization techniques that can be detrimental to cells or other bioactive molecules. The degradation of these DNA-cross-linked hydrogels upon exposure to the model endonucleases Benzonase(®) and DNase I was studied. In addition, the ability of the hydrogels to act as depots for encapsulation and nuclease-controlled release of a model protein was demonstrated. This model has the potential to be tailored and expanded upon for use in a variety of applications where mild hydrogel preparation techniques and controlled material degradation are necessary including in drug delivery and wound healing systems.

  12. Effect of polyethylene glycol 6000 and storage period on seed quality of cocoa (Theobroma cacao L.

    Directory of Open Access Journals (Sweden)

    Astiti Rahayu

    2014-05-01

    Full Text Available Increased productivity of cocoa needs high quality of cocoa seeds which are generally provided by certified seed gardens located far from smallholders farm, where seed delivery takes long time and may reduce physiological quality of seeds. One effort to maintain the seed quality is by treatment the seeds with polyethylene glycol6000 (PEG 6000. This study was aimed to study the interaction of PEG 6000 concentration and storage period on cocoa seed quality, and to determine the best concentration of PEG 6000 and storage period to maintain cocoa seed quality. The research was conducted in seed storage room, seed laboratory and green houseof PPPPTK, Cianjur. The experimental design used was a factorial completely randomized design and each combination treatment repeated three times. The first factor was concentration of PEG 6000 of 0%, 20%, 40%, and 60%, and the second factor was the storage period of 3 weeks, 6 weeks, 9 weeks, and 12 weeks. The results showed that concentration of PEG 60% with three weeks storage period was able to minimize the number of moldy seeds. The concentration of PEG 20%, 40%, and 60% were able to prevent seed germination in storage until six weeks. Concentration of PEG 6000 20% was able to maintain moisture content, seed germination, and germination rate.Key words:cocoa seed, storage, recalcitrant, PEG

  13. Versatile Route to Synthesize Heterobifunctional Poly(ethylene glycol of Variable Functionality for Subsequent Pegylation

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    Redouan Mahou

    2012-02-01

    Full Text Available Pegylation using heterotelechelic poly(ethylene glycol (PEG offers many possibilities to create high-performance molecules and materials. A versatile route is proposed to synthesize heterobifunctional PEG containing diverse combinations of azide, amine, thioacetate, thiol, pyridyl disulfide, as well as activated hydroxyl end groups. Asymmetric activation of one hydroxyl end group enables the heterobifunctionalization while applying selective monotosylation of linear, symmetrical PEG as a key step. The azide function is introduced by reacting monotosyl PEG with sodium azide. A thiol end group is obtained by reaction with sodium hydrosulfide. The activation of the hydroxyl end group and subsequent reaction with potassium carbonate/thioacetic acid yields a thioacetate end group. The hydrolysis of the thioester end group by ammonia in presence of 2,2′-dipyridyl disulfide provides PEG pyridyl disulfide. Amine terminated PEG is prepared either by reduction of the azide or by nucleophilic substitution of mesylate terminated PEG using ammonia. In all cases, >95% functionalization of the PEG end groups is achieved. The PEG derivatives particularly support the development of materials for biomedical applications. For example, grafting up to 13% of the Na-alg monomer units with α-amine-ω-thiol PEG maintains the gelling capacity in presence of calcium ions but simultaneous, spontaneous disulfide bond formation reinforces the initial physical hydrogel.

  14. Surface modification of PDMS microchips with poly(ethylene glycol) derivatives for μTAS applications.

    Science.gov (United States)

    de Campos, Richard Piffer Soares; Yoshida, Inez Valeria Pagotto; da Silva, José Alberto Fracassi

    2014-08-01

    In this work is presented a method for the modification of native PDMS surface in order to improve its applicability as a substrate for microfluidic devices, especially in the analysis of nonpolar analytes. Therefore, poly(ethylene glycol) divinyl ether modified PDMS substrate was obtained by surface modification of native PDMS. The modified substrate was characterized by attenuated total reflectance infrared spectroscopy, water contact angle measurements, and by evaluating the adsorption of rhodamine B and the magnitude of the EOF mobility. The reaction was confirmed by the spectroscopic evaluation. The formation of a well-spread water film over the surface immediately after the modification was an indicative of the modified surface hydrophilicity. This characteristic was maintained for approximately ten days, with a gradual return to a hydrophobic state. Fluorescence assays showed that the nonpolar adsorption property of PDMS was significantly decreased. The EOF mobility obtained was 3.6 × 10(-4) cm(2) V(-1) s(-1) , higher than the typical values found for native PDMS. Due to the better wettability promoted by the modification, the filling of the microchannels with aqueous solutions was facilitated and trapping of air bubbles was not observed.

  15. Influence of ethylene glycol pretreatment on effectiveness of atmospheric pressure plasma treatment of polyethylene fibers

    Energy Technology Data Exchange (ETDEWEB)

    Wen Ying; Li Ranxing [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education (China); Cai Fang [Key Laboratory of Eco-Textiles (Donghua University), Ministry of Education (China); Fu Kun; Peng Shujing; Jiang Qiuran; Yao Lan [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education (China); Qiu Yiping, E-mail: ypqiu@dhu.edu.cn [Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China)

    2010-03-01

    For atmospheric pressure plasma treatments, the results of plasma treatments may be influenced by liquids adsorbed into the substrate. This paper studies the influence of ethylene glycol (EG) pretreatment on the effectiveness of atmospheric plasma jet (APPJ) treatment of ultrahigh molecular weight polyethylene (UHMWPE) fibers with 0.31% and 0.42% weight gain after soaked in EG/water solution with concentration of 0.15 and 0.3 mol/l for 24 h, respectively. Scanning electron microscopy (SEM) shows that the surface of fibers pretreated with EG/water solution does not have observable difference from that of the control group. The X-ray photoelectron spectroscopy (XPS) results show that the oxygen concentration on the surface of EG-pretreated fibers is increased less than the plasma directly treated fibers. The interfacial shear strength (IFSS) of plasma directly treated fibers to epoxy is increased almost 3 times compared with the control group while that of EG-pretreated fibers to epoxy does not change except for the fibers pretreated with lower EG concentration and longer plasma treatment time. EG pretreatment reduces the water contact angle of UHMWPE fibers. In conclusion, EG pretreatment can hamper the effect of plasma treatment of UHMWPE fibers and therefore longer plasma treatment duration is required for fibers pretreated with EG.

  16. Unexpected Temperature Behavior of Polyethylene Glycol Spacers in Copolymer Dendrimers in Chloroform

    Science.gov (United States)

    Markelov, Denis A.; Matveev, Vladimir V.; Ingman, Petri; Nikolaeva, Marianna N.; Penkova, Anastasia V.; Lahderanta, Erkki; Boiko, Natalia I.; Chizhik, Vladimir I.

    2016-04-01

    We have studied copolymer dendrimer structure: carbosilane dendrimers with terminal phenylbenzoate mesogenic groups attached by poly(ethylene) glycol (PEG) spacers. In this system PEG spacers are additional tuning to usual copolymer structure: dendrimer with terminal mesogenic groups. The dendrimer macromolecules were investigated in a dilute chloroform solution by 1H NMR methods (spectra and relaxations). It was found that the PEG layer in G = 5 generations dendrimer is “frozen” at high temperatures (above 260 K), but it unexpectedly becomes “unfrozen” at temperatures below 250 K (i.e., melting when cooling). The transition between these two states occurs within a small temperature range (~10 K). Such a behavior is not observed for smaller dendrimer generations (G = 1 and 3). This effect is likely related to the low critical solution temperature (LCST) of PEG and is caused by dendrimer conformations, in which the PEG group concentration in the layer increases with growing G. We suppose that the unusual behavior of PEG fragments in dendrimers will be interesting for practical applications such as nanocontainers or nanoreactors.

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

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    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. Improved Biofilm Antimicrobial Activity of Polyethylene Glycol Conjugated Tobramycin Compared to Tobramycin in Pseudomonas aeruginosa Biofilms.

    Science.gov (United States)

    Du, Ju; Bandara, H M H N; Du, Ping; Huang, Hui; Hoang, Khang; Nguyen, Dang; Mogarala, Sri Vasudha; Smyth, Hugh D C

    2015-05-04

    The objective of this study was to develop a functionally enhanced antibiotic that would improve the therapeutic activity against bacterial biofilms. Tobramycin was chemically conjugated with polyethylene glycol (PEG) via site-specific conjugation to form PEGylated-tobramycin (Tob-PEG). The antibacterial efficacy of Tob-PEG, as compared to tobramycin, was assessed on the planktonic phase and biofilms phase of Pseudomonas aeruginosa. The minimum inhibitory concentration (MIC80) of Tob-PEG was higher (13.9 μmol/L) than that of tobramycin (1.4 μmol/L) in the planktonic phases. In contrast, the Tob-PEG was approximately 3.2-fold more effective in eliminating bacterial biofilms than tobramycin. Specifically, Tob-PEG had a MIC80 lower than those exhibited by tobramycin (27.8 μmol/L vs 89.8 μmol/L). Both confocal laser scanning microscopy and scanning electron microscopy further confirmed these data. Thus, modification of antimicrobials by PEGylation appears to be a promising approach for overcoming the bacterial resistance in the established biofilms of Pseudomonas aeruginosa.

  19. Dynamic properties of the polyethylene glycol molecules on the oscillating solid-liquid interface.

    Science.gov (United States)

    Yoshimoto, Minoru; Yuda, Yukiko; Aizawa, Hidenobu; Sato, Hiroaki; Kurosawa, Shigeru

    2012-06-20

    The dynamic properties of polyethylene glycol (PEG) molecules on the solid-liquid interface oscillating at MHz were investigated using the quartz crystal microbalance (QCM). The number-average molecular weights (M(n)) of the PEG molecules were systematically varied over 4 orders of magnitude. This study makes it clear that the series-resonant frequency shift, ΔF, of the QCM against the square root of the density-viscosity product of the PEG solution is linear and has the intercept. Moreover, systematical analysis reveals that the ΔF slope rapidly decreases with M(n) and that the ΔF intercept becomes constant above 4.0×10(3) g mol(-1). As a result, those reveal that the resonant length of the PEG molecule moving with the oscillating plate of 9 MHz is 54.2 Å. We also find that the behaviors of ΔF due to M(n) are mainly caused by the length of the PEG molecule. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Infrared and Raman studies on polylactide acid and polyethylene glycol-400 blend

    Science.gov (United States)

    Yuniarto, Kurniawan; Purwanto, Yohanes Aris; Purwanto, Setyo; Welt, Bruce A.; Purwadaria, Hadi Karia; Sunarti, Titi Candra

    2016-04-01

    As a biodegradableplastic, polylactideacid (PLA) can be blended with polyethylene glycol (PEG) to form a polymer blend because PEG has a good miscibility with PLA. Furthermore, this paper study the functional groups of PLA-PEG400 blend using direct casting to produce matrix film. Fourier Transform Infrared (FTIR) and Raman spectroscopy was used to identify alteration of functional group PLA-PEG400 blend. Absorbance and frequency wavenumber were used to observe any changing among functional group. In general, PLA-PEG blend did not produce a new configuration or chemical properties although some functional groups tended to decrease. PLA-PEG400 film spectra showed a similaritycompared to those of neat PLA because of each pristine polymer. However, FTIR and Raman investigated reducing carbonyl group of PLA with PEG400 addition and followed improving CH-COC bonding. Methyl group represented CH3symmetricchanged both the shift and absorbance.FTIR and Raman spectroscopy observed increasing hydrogen bonding with increasing PEG400 addition where a largest was found at PEG 10% and appeared at frequency range from 3400 cm-1 to 3600 cm-1. According to PEG400 addition, a FTIR measuredenhancing crystalline region.

  1. Poly(ethylene glycol)-block-cationic polylactide nanocomplexes of differing charge density for gene delivery.

    Science.gov (United States)

    Chen, Chih-Kuang; Jones, Charles H; Mistriotis, Panagiotis; Yu, Yun; Ma, Xiaoni; Ravikrishnan, Anitha; Jiang, Ming; Andreadis, Stelios T; Pfeifer, Blaine A; Cheng, Chong

    2013-12-01

    Representing a new type of biodegradable cationic block copolymer, well-defined poly(ethylene glycol)-block-cationic polylactides (PEG-b-CPLAs) with tertiary amine-based cationic groups were synthesized by thiol-ene functionalization of an allyl-functionalized diblock precursor. Subsequently the application of PEG-b-CPLAs as biodegradable vectors for the delivery of plasmid DNAs (pDNAs) was investigated. Via the formation of PEG-b-CPLA:pDNA nanocomplexes by spontaneous electrostatic interaction, pDNAs encoding luciferase or enhanced green fluorescent protein were successfully delivered to four physiologically distinct cell lines (including macrophage, fibroblast, epithelial, and stem cell). Formulated nanocomplexes demonstrated high levels of transfection with low levels of cytotoxicity and hemolysis when compared to a positive control. Biophysical characterization of charge densities of nanocomplexes at various polymer:pDNA weight ratios revealed a positive correlation between surface charge and gene delivery. Nanocomplexes with high surface charge densities were utilized in an in vitro serum gene delivery inhibition assay, and effective gene delivery was observed despite high levels of serum. Overall, these results help to elucidate the influence of charge, size, and PEGylation of nanocomplexes upon the delivery of nucleic acids in physiologically relevant conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Modulation of Human Colostrum Phagocyte Activity by the Glycine-Adsorbed Polyethylene Glycol Microspheres

    Directory of Open Access Journals (Sweden)

    Paulo Celso Leventi Guimarães

    2013-01-01

    Full Text Available Colostrum is a secretion that contains immunologically active components, including immunocompetent cells and glycine, which has anti-inflammatory, immunomodulatory, and cytoprotective effects. The aim of this study was to evaluate the adsorption of glycine onto polyethylene glycol (PEG microspheres and to verify the immunomodulatory effect of this nanomaterial on human colostrum phagocytes. The PEG microspheres were evaluated by fluorescence microscopy. The effects of PEG microspheres with adsorbed glycine on viability, superoxide release, phagocytosis, microbicidal activity, and intracellular calcium release of mononuclear (MN and polymorphonuclear (PMN colostrum phagocytes were determined. Fluorescence microscopy analyses revealed that glycine was able to be adsorbed to the PEG microspheres. The PMN phagocytes exposed to glycine-PEG microspheres showed the highest superoxide levels. The phagocytes (both MN and PMN displayed increased microbicidal activity and intracellular calcium release in the presence of PEG microspheres with adsorbed glycine. These data suggest that the adsorption of PEG microspheres with adsorbed glycine was able to stimulate the colostrum phagocytes. This material may represent a possible alternative therapy for future clinical applications on patients with gastrointestinal infections.

  3. Effect of inorganic salts on crystallization of poly(ethylene glycol) in frozen solutions.

    Science.gov (United States)

    Izutsu, Ken-ichi; Aoyagi, Nobuo

    2005-01-06

    The effect of inorganic salts on eutectic crystallization of poly(ethylene glycol) (PEG) 1500-20,000 in frozen solution was studied to model the polymer and inorganic salt interaction in freeze-dried formulations. Thermal analysis of an aqueous PEG 3000 solution showed a eutectic PEG crystallization exotherm at approximately -47 degrees C and a subsequent PEG crystal melting endotherm at -14.9 degrees C. Addition of sodium chloride prevented the PEG crystallization in the freeze-concentrated solution surrounding ice crystals. Higher concentration NaCl was required to retain higher molecular weight PEG in the amorphous state. Various inorganic salts prevented the PEG crystallization to varying degrees depending mainly on the position of the anion in the Hofmeister's lyotropic series. Some salting-in and 'intermediate' salts (NaSCN, NaI, NaBr, NaCl, LiCl, KCl, and RbCl) inhibited the crystallization of PEG 7500 in frozen solutions. On the other hand, salting-out salts (NaH2PO4, Na2HPO4, Na2SO4, and NaF) did not show an apparent effect on the PEG crystallization. Some salting-out salts induced PEG crystallization in PEG and sucrose combination frozen solutions. The varying abilities of salts to prevent the PEG crystallization in frozen solutions strongly suggested that the solutes had different degrees of miscibility in the freeze-concentrates.

  4. Biomimetic myocardial patches fabricated with poly(ɛ-caprolactone) and polyethylene glycol-based polyurethanes.

    Science.gov (United States)

    Silvestri, Antonella; Sartori, Susanna; Boffito, Monica; Mattu, Clara; Di Rienzo, Anna M; Boccafoschi, Francesca; Ciardelli, Gianluca

    2014-07-01

    The production of efficient heart patches for myocardium repair requires the use of biomaterials with high elastomeric properties and controllable biodegradability. To fulfil these design criteria we propose biodegradable poly(ester urethanes) and poly(ether ester urethanes) from poly(ɛ-caprolactone) (PCL) and poly(ethylene glycol) (PEG) as macrodiols, 1,4-diisocyanatobutane as diisocyanate, l-Lysine Ethyl Ester and Alanine-Alanine-Lysine (AAK) as chain extenders. This peptide was used to tune biodegradability properties, since the Alanine-Alanine sequence is a target for the elastase enzyme. Enzymatic degradation tests demonstrated the feasibility of tuning biodegradability properties due to the introduction of AAK peptide in polyurethane backbone. Two formulations have been processed into porous scaffolds by Thermally-Induced Phase Separation (TIPS). Scanning Electron Microscopy micrographs revealed promising microstructures, which were characterized by stretched and unidirectional pores and mimicked the striated muscle tissue. Tensile tests showed that, although scaffolds are characterized by lower mechanical properties than films, these substrates have suitable elastomeric behaviors and elastic moduli for contractile and soft tissue regeneration. Viability tests on cardiomyocytes revealed the best cell response for dense film and porous scaffold obtained from PCL and Lysine Ethyl Ester-based polyurethane, with an increased viability for the porous substrate, which is ascribable to the morphological features of its microstructure. Future works will be addressed to study the in vivo behavior of these constructs and to confirm their applicability for myocardial tissue engineering.

  5. Identification and Extraction of Chicken Egg Yolk Immunoglobulin from Egg by Polyethylene Glycol (PEG Precipitation

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    Mohammad Mehdi Soltan Dallal

    2016-02-01

    Full Text Available Background: Staphylococcus aureus strains exhibiting multiple antibiotic resistances are isolated from most communities and hospital infections. Treatment of patients with these infections has been difficult. The aim of this study was to detect and extract, the egg yolk immunoglobulin Y as a potential source of anti- S. aureus antibody.Methods: Specific IgY was produced by immunizing hens with formalin-killed S. aureus. The specificity of serum`s antibody was confirmed by ELISA method. The antibodies were extracted from egg yolk by polyethylene glycol (PEG precipitation. Proteins were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE.Results: Chicken egg yolk antibodies (IgY were raised against S. aureus in the serum after injections. Up to 104 dilution specific antibodies were determined in serum. Conclusion: The results of the ELISA indicates the specificity of the immunoglobulin Y to the target antigen. In order to find a viable alternative to antibiotic treatments, more research must be done on the ability of these antibodies to inhibit the growth of S. aureus.

  6. Identification and Extraction of Chicken Egg Yolk Immunoglobulin from Egg by Polyethylene Glycol (PEG Precipitation

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Soltan Dallal

    2016-01-01

    Full Text Available Background: Staphylococcus aureus strains exhibiting multiple antibiotic resistances are isolatedfrom most communities and hospital infections. Treatment of patients with these infections hasbeen difficult. The aim of this study was to detect and extract, the egg yolk immunoglobulin Y asa potential source of anti- S. aureus antibody.Methods: Specific IgY was produced by immunizing hens with formalin-killed S. aureus. Thespecificity of serum`s antibody was confirmed by ELISA method. The antibodies were extractedfrom egg yolk by polyethylene glycol (PEG precipitation. Proteins were analysed by sodiumdodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE.Results: Chicken egg yolk antibodies (IgY were raised against S. aureus in the serum afterinjections. Up to 104 dilution specific antibodies were determined in serum.Conclusion: The results of the ELISA indicates the specificity of the immunoglobulin Y to thetarget antigen. In order to find a viable alternative to antibiotic treatments, more research must bedone on the ability of these antibodies to inhibit the growth of S. aureus.

  7. 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.

  8. Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds.

    Science.gov (United States)

    Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md Rakibul

    2016-06-29

    A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075-10 µM and 10-55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days.

  9. Transactivating-transduction protein-polyethylene glycol modified liposomes traverse the blood-spinal cord and blood-brain barriers

    Institute of Scientific and Technical Information of China (English)

    Xianhu Zhou; Chunyuan Wang; Shiqing Feng; Jin Chang; Xiaohong Kong; Yang Liu; Shijie Gao

    2012-01-01

    Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fluorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells (MCF-7). Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers.

  10. Effect of sodium chloride on solute-solvent interactions in aqueous polyethylene glycol-sodium sulfate two-phase systems.

    Science.gov (United States)

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-12-18

    Partition behavior of eight small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.215M NaCl and 0.5M osmolyte (sorbitol, sucrose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate-0.215M NaCl system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. The partition coefficients of all compounds examined (including proteins) were described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system change in the presence of NaCl additive.

  11. Characterization of gliclazide-polyethylene glycol solid dispersion and its effect on dissolution

    Directory of Open Access Journals (Sweden)

    Moreshwar Pandharinath Patil

    2011-03-01

    Full Text Available The present study was initiated with the objective of studying the in vitro dissolution behavior of gliclazide from its solid dispersion with polyethylene glycol 6000. In this work, a solid dispersion of gliclazide with polyethylene glycol was prepared by the fusion method. In vitro dissolution study of gliclazide, its physical mixture and solid dispersion were carried out to demonstrate the effect of PEG 6000. Analytical techniques of FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry were used to characterize the drug in the physical mixtures and solid dispersions. The dissolution studies of solid dispersion and physical mixture showed greater improvement compared to that of the pure drug. The mechanisms for increased dissolution rate may include reduction of crystallite size, a solubilization effect of the carrier, absence of aggregation of drug crystallites, improved wettability and dispersbility of the drug from the dispersion, dissolution of the drug in the hydrophilic carrier or conversion of drug to an amorphous state. The FT-IR spectra suggested that there was no interaction between gliclazide and PEG 6000 when prepared as a solid dispersion. DSC and XRD study indicated that the drug was converted in the amorphous form.O presente trabalho foi realizado com o objetivo de estudar o comportamento in vitro da dissolução da gliclazida a partir da sua dispersão sólida com polietileno glicol 6000. Neste trabalho, as dispersões sólidas de gliclazida com polietileno glicol foram preparadas pelo método de fusão. Os estudo de dissolução in vitro da gliclazida, na mistura física e nas dispersões sólidas foram realizados para demonstrar o efeito de PEG 6000. Técnicas analíticas como espectroscopia FT-IR, calorimetria diferencial de varredura e difração de raios-X foram empregadas para caracterizar o fármaco nas misturas físicas e nas dispersoes sólidas. Os estudos de dissolução demonstraram maior

  12. Efficiency of SPIONs functionalized with polyethylene glycol bis(amine) for heavy metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Wanna, Yongyuth, E-mail: yongyuth.wanna@gmail.com [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand); Nara Machinery Co., Ltd., 2-5-7, Jonan-Jima, Ohta-ku, Tokyo 143-0002 (Japan); Chindaduang, Anon; Tumcharern, Gamolwan [National Nanotechnology Center (NANOTEC), 111 Thailand Science Park, Pahol Yothin Rd, Klong Luang, Pathum Thani 12120 (Thailand); Phromyothin, Darinee [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand); Porntheerapat, Supanit [NECTEC, National Science and Technology Development Agency (NSTDA), 112 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120 (Thailand); Nukeaw, Jiti [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand); Hofmann, Heirich [Laboratory of Powder Technology, Ecole Polytechnique Fédérale de Lausanne (Switzerland); Pratontep, Sirapat [College of KMITL Nanotechnology, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Rd., Ladkrabang, Bangkok 10520 (Thailand)

    2016-09-15

    Hybrid magnetic nanoparticles based on poly(methylmethacrylate) (PMMA) and super-paramagnetic iron oxide nanopaticles (SPIONs) with selective surface modification has been developed for heavy metal removal by applying external magnetic fields. The nanoparticles were prepared by the emulsion polymerization technique in an aqueous suspension of SPIONs. The hydrolysis of carboxyl functional group was then applied for grafting polyethylene glycol bis(amine)(PEG-bis(amine)) onto the PMMA-coated SPIONs. The morphology, the chemical structure and the magnetic properties of the grafted nanoparticles were investigated. The efficiency of the hybrid nanoparticles for heavy metal removal were conducted on Pb(II), Hg(II), Cu(II) and Co(II) in aqueous solutions.The metal concentration in the solutions after separation by the hybrid nanoparticles was determined by inductively coupled plasma optical emission spectrometer (ICP-OES). The results show the heavy metal uptake ratios of 0.08, 0.04, 0.03, and 0.01 mM per gramme of the grafted SPIONs for Pb(II), Hg(II), Cu(II), and Co(II), respectively. A competitive removal of Cu(II), Pb(II), Co(II) and Hg(II) ions in mixed metal salt solutions has also been studied.The heavy metal removal efficiency of the hybrid nanoparitcles was found to depend on the cation radius, in accordance with capture of metal ions by the amine group. - Highlights: • We synthesis hybrid magnetic nanoparticles for heavy metal removal. • The efficiency of hybrid nanoparticles for heavy metal removal is proposed. • We investigated the characteristic of hybrid nanoparticle. • The heavy metal removal efficiency of the hybrid nanoparticle was founded that depend on the heavy metal cation radius.

  13. Antioxidant response of Stevia rebaudiana B. to polyethylene glycol and paclobutrazol treatments under in vitro culture.

    Science.gov (United States)

    Hajihashemi, Shokoofeh; Ehsanpour, Ali Akbar

    2014-04-01

    This investigation was carried out with the aim of determining the effect of paclobutrazol (PBZ) (0 and 2 mg l(-1)) and polyethylene glycol (PEG) (0, 2, 4 and 6 % w/v of PEG 6000) treatments on antioxidant system of Stevia rebaudiana Bertoni under in vitro condition. Analysis of data showed that PEG treatment significantly increased hydrogen peroxide (H2O2) and phenolic contents, while PBZ treatment limited the effect of PEG on them. Our data revealed that PEG treatment significantly increased total antioxidant capacity, catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and peroxidase (POD) activity, while it inversely decreased glutathione reductase (GR) activity. The superoxide dismutase (SOD) activity was not affected by PEG treatment. PBZ treatment induced significantly higher levels of CAT and GR activity and lower levels of SOD activity in PEG-treated plants. PBZ in combination with PEG resulted in no significant difference on APX activity with PEG treatment alone. PBZ treatment prevented the effect of PEG on the PPO activity. PEG (with or without PBZ) treatment increased the ascorbate pool, whereas total glutathione level was not affected by PEG. Our finding indicated that PBZ reduced the negative effect of PEG treatment by quenching H2O2 accumulation and increasing the CAT activity. Collectively, the antioxidant capacity of S. rebaudiana in PEG treatment condition was associated with active enzymatic and non-enzymatic defence systems which partly could be improved by the PBZ treatment. In addition, a higher accumulation of phenolic compounds leads to a more potent reactive oxygen species scavenging activity in S. rebaudiana.

  14. Polyethylene Glycol-Mediated Synthesis of Cubic Iron Oxide Nanoparticles with High Heating Power

    Science.gov (United States)

    Iacovita, Cristian; Stiufiuc, Rares; Radu, Teodora; Florea, Adrian; Stiufiuc, Gabriela; Dutu, Alina; Mican, Sever; Tetean, Romulus; Lucaciu, Constantin M.

    2015-10-01

    Iron oxide magnetic nanoparticles (IOMNPs) have been successfully synthesized by means of solvothermal reduction method employing polyethylene glycol (PEG200) as a solvent. The as-synthesized IOMNPs are poly-dispersed, highly crystalline, and exhibit a cubic shape. The size of IOMNPs is strongly dependent on the reaction time and the ration between the amount of magnetic precursor and PEG200 used in the synthesis method. At low magnetic precursor/PEG200 ratio, the cubic IOMNPs coexist with polyhedral IOMNPs. The structure and morphology of the IOMNPs were thoroughly investigated by using a wide range of techniques: TEM, XRD, XPS, FTIR, and RAMAN. XPS analysis showed that the IOMNPs comprise a crystalline magnetite core bearing on the outer surface functional groups from PEG200 and acetate. The presence of physisorbed PEG200 on the IOMNP surface is faintly detected through FT-IR spectroscopy. The surface of IOMNPs undergoes oxidation into maghemite as proven by RAMAN spectroscopy and the occurrence of satellite peaks in the Fe2p XP spectra. The magnetic studies performed on powder show that the blocking temperature (TB) of IOMNPs is around 300 K displaying a coercive field in between 160 and 170 Oe. Below the TB, the field-cooled (FC) curves turn concave and describe a plateau indicating that strong magnetic dipole-dipole interactions are manifested in between IOMNPs. The specific absorption rate (SAR) values increase with decreasing nanoparticle concentrations for the IOMNPs dispersed in water. The SAR dependence on the applied magnetic field, studied up to magnetic field amplitude of 60 kA/m, presents a sigmoid shape with saturation values up to 1700 W/g. By dispersing the IOMNPs in PEG600 (liquid) and PEG1000 (solid), it was found that the SAR values decrease by 50 or 75 %, indicating that the Brownian friction within the solvent was the main contributor to the heating power of IOMNPs.

  15. Two-step recrystallization of water in concentrated aqueous solution of poly(ethylene glycol).

    Science.gov (United States)

    Gemmei-Ide, Makoto; Motonaga, Tetsuya; Kasai, Ryosuke; Kitano, Hiromi

    2013-02-21

    Crystallization behavior of water in a concentrated aqueous solution of poly(ethylene glycol) (PEG) with a water content of 37.5 wt % was investigated by temperature variable mid-infrared (mid-IR) spectroscopy in a temperature range of 298-170 K. The mid-IR spectrum of water at 298 K showed that a large water cluster was not formed and that most of the water molecules were associated with the PEG chain. Ice formation, however, occurred as found in previous studies by differential scanning calorimetory. Ice formations were grouped into three types: crystallization at 231 K during cooling, that at 198 K during heating, and that at 210 K during heating. The latter two were just recrystallization. These ice formations were the direct transition from hydration species to ice without condensation regardless of crystallization or recrystallization. This means that the recrystallized water in the present system was not generated from low-density amorphous solid water. At a low cooling rate, nearly complete crystallization at 231 K during cooling and no recrystallization were observed. At a high cooling rate, no crystallization and two-step recrystallization at 198 and 210 K were observed. The former and latter recrystallizations were found to be generated from water associated with the PEG chains with ttg (the sequence -O-CH(2)-CH(2)-O- having a trans (t) conformation about the -C-O- bond and a gauche (g) conformation about the -C-C- bond) and random conformations, respectively. These results indicate that recrystallizable water does not have a single specific water structure.

  16. Pharmacokinetic and thrombolytic properties of cysteine-linked polyethylene glycol derivatives of staphylokinase.

    Science.gov (United States)

    Vanwetswinkel, S; Plaisance, S; Zhi-Yong, Z; Vanlinthout, I; Brepoels, K; Lasters, I; Collen, D; Jespers, L

    2000-02-01

    Recombinant staphylokinase (SakSTAR) variants obtained by site-directed substitution with cysteine, in the core (lysine 96 [Lys96], Lys102, Lys109, and/or Lys135) or the NH(2)-terminal region that is released during activation of SakSTAR (serine 2 [Ser2] and/or Ser3), were derivatized with thiol-specific (ortho-pyridyl-disulfide or maleimide) polyethylene glycol (PEG) molecules with molecular weights of 5,000 (P5), 10,000 (P10), or 20,000 (P20). The specific activities and thrombolytic potencies in human plasma were unaltered for most variants derivatized with PEG (PEGylates), but maleimide PEG derivatives had a better temperature stability profile. In hamsters, SakSTAR was cleared at 2.2 mL/min; variants with 1 P5 molecule were cleared 2-to 5-fold; variants with 2 P5 or 1 P10 molecules were cleared 10-to 30-fold; and variants with 1 P20 molecule were cleared 35-fold slower. A bolus injection induced dose-related lysis of a plasma clot, fibrin labeled with 125 iodine ((125)I-fibrin plasma clot), and injected into the jugular vein. A 50% clot lysis at 90 minutes required 110 microg/kg SakSTAR; 50 to 110 microg/kg of core-substitution derivatives with 1 P5; 25 microg/kg for NH(2)-terminal derivatives with 1 P5; 5 to 25 microg/kg with derivatives with 2 P5 or 1 P10; and 7 microg/kg with P20 derivatives. Core substitution with 1 or 2 P5 molecules did not significantly reduce the immunogenicity of SakSTAR in rabbits. Derivatization of staphylokinase with a single PEG molecule allows controllable reduction of the clearance while maintaining thrombolytic potency at a reduced dose. This indicates that mono-PEGylated staphylokinase variants may be used for single intravenous bolus injection.

  17. Ligand conjugation to bimodal poly(ethylene glycol) brush layers on microbubbles.

    Science.gov (United States)

    Chen, Cherry C; Borden, Mark A

    2010-08-17

    Using microbubbles as model systems, we examined molecular diffusion and binding to colloidal surfaces in bimodal poly(ethylene glycol) (PEG) brush layers. A microbubble is a gaseous colloidal particle with a diameter of less than 10 mum, of which the surface comprises amphiphilic phospholipids self-assembled to form a lipid monolayer shell. Due to the compressible gas core, microbubbles provide a sensitive acoustic response and are currently used as ultrasound contrast agents. Similar to the design of long circulating liposomes, PEG chains are typically incorporated into the shell of microbubbles to form a steric barrier against coalescence and adsorption of macromolecules to the microbubble surface. We introduced a buried-ligand architecture (BLA) design where the microbubble surface was coated with a bimodal PEG brush. After microbubbles were generated, fluorescent ligands with different molecular weights were conjugated to the tethered functional groups on the shorter PEG chains, while the longer PEG chains served as a shield to protect these ligands from exposure to the surrounding environment. BLA microbubbles reduced the binding of macromolecules (>10 kDa) to the tethers due to the steric hindrance of the PEG overbrush while allowing the uninhibited attachment of small molecules (microbubbles compared to exposed-ligand architecture (ELA) microbubbles. The binding of SA-FITC to BLA microbubbles suggested a possible phase separation between the lipid species on the surface leading to populations of revealed and concealed ligands. Ligand conjugation kinetics was independent of microbubble size, regardless of ligand size or microbubble architecture. We observed, for the first time, streptavidin-induced surface structure formation for ELA microbubbles and proposed that this phenomenon may be correlated to flow cytometry scattering measurements. We therefore demonstrated the feasibility of postlabeling for small-molecule ligands to BLA microbubbles to generate

  18. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava.

    Science.gov (United States)

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-01-01

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment.

  19. A Comprehensive Study of Photorefractive Properties in Poly(ethylene glycol Dimethacrylate— Ionic Liquid Composites

    Directory of Open Access Journals (Sweden)

    Mostafa A. Ellabban

    2016-12-01

    Full Text Available A detailed investigation of the recording, as well as the readout of transmission gratings in composites of poly(ethylene glycol dimethacrylate (PEGDMA and ionic liquids is presented. Gratings with a period of about 5.8 micrometers were recorded using a two-wave mixing technique with a coherent laser beam of a 355-nm wavelength. A series of samples with grating thicknesses d 0 = 10 … 150 micrometers, each for two different exposure times, was prepared. The recording kinetics, as well as the post-exposure properties of the gratings were monitored by diffracting a low intensity probe beam at a wavelength of 633 nm for Bragg incidence. To obtain a complete characterization, two-beam coupling experiments were conducted to clarify the type and the strength of the recorded gratings. Finally, the diffraction efficiency was measured as a function of the readout angle at different post-exposure times. We found that, depending on the parameters, different grating types (pure phase and/or mixed are generated, and at elevated thicknesses, strong light-induced scattering develops. The measured angular dependence of the diffraction efficiency can be fitted using a five-wave coupling theory assuming an attenuation of the gratings along the thickness. For grating thicknesses larger than 85 microns, light-induced scattering becomes increasingly important. The latter is an obstacle for recording thicker holograms, as it destroys the recording interference pattern with increasing sample depth. The obtained results are valuable in particular when considering PEGDMA-ionic liquid composites in the synthesis of advanced polymer composites for applications, such as biomaterials, conductive polymers and holographic storage materials.

  20. Low thrombogenicity of polyethylene glycol-grafted cellulose membranes does not influence heparin requirements in hemodialysis.

    Science.gov (United States)

    Wright, M J; Woodrow, G; Umpleby, S; Hull, S; Brownjohn, A M; Turney, J H

    1999-07-01

    Heparin is the most commonly used anticoagulant for hemodialysis despite potentially serious side effects. Polyethylene glycol-grafted cellulose (PGC) membranes produce less activation of the coagulation cascade than cuprophane membranes. Anecdotally, we found some patients required a surprisingly low level of anticoagulation using these membranes. We compared the anticoagulant requirement of the PGC membrane with that of the cuprophane membrane in this randomized, prospective, crossover study. Sixty-three patients were randomized to treatment using either membrane, and heparin administration was progressively reduced to the lowest dose that prevented visible clotting in excess of that normally encountered. Patients underwent dialysis at this dose for 1 month, after which the heparin requirement and Kt/Vurea (1.162 x ln [urea pre/urea post]) were assessed. This process was then repeated for each patient using the other membrane, and the results were compared. Heparin administration during dialysis was reduced from a mean loading dose of 29.0 +/- 9.4 to 1.5 +/- 3.2 IU/kg for both membranes and a mean maintenance infusion of 14.0 +/- 6.7 to 0.77 +/- 1.6 IU/kg/h for both membranes (both P < 0.0001 v full anticoagulation; no difference between membranes). The Kt/Vurea was not significantly altered. Forty-six patients with PGC and 45 patients with cuprophane membranes underwent dialysis successfully without heparin during dialysis, and the other patients were using considerably reduced doses. Aspirin and warfarin had no effect on the heparin requirement. These results do not support the theory that PGC membranes have a lower anticoagulant requirement than cuprophane membranes; however, they suggest that dialysis can be performed successfully with much smaller anticoagulant doses than are currently in common use.

  1. Polyethylene glycol reduces early and long-term cold ischemia-reperfusion and renal medulla injury.

    Science.gov (United States)

    Faure, Jean Pierre; Hauet, Thierry; Han, Zeqiu; Goujon, Jean Michel; Petit, Isabelle; Mauco, Gerard; Eugene, Michel; Carretier, Michel; Papadopoulos, Vassilios

    2002-09-01

    Ischemia-reperfusion injury (IRI) after transplantation is a major cause of delayed graft function, which has a negative impact on early and late graft function and improve acute rejection. We have previously shown that polyethylene glycol (PEG) and particularly PEG 20M has a protective effect against cold ischemia and reperfusion injury in an isolated perfused pig and rat kidney model. We extended those observations to investigate the role of PEG using different doses (30g or 50g/l) added (ICPEG30 or ICPEG50) or not (IC) to a simplified preservation solution to reduce IRI after prolonged cold storage (48-h) of pig kidneys when compared with Euro-Collins and University of Wisconsin solutions. The study of renal function and medulla injury was performed with biochemical methods and proton NMR spectroscopy. Histological and inflammatory cell studies were performed after reperfusion (30-40 min) and on days 7 and 14 and weeks 4, 8, and 12. Peripheral-type benzodiazepine receptor (PBR), a mitochondrial protein involved in cholesterol homeostasis, was also studied. The results demonstrated that ICPEG30 improved renal function and reduced medulla injury. ICPEG30 also improved tubular function and strongly protect mitochondrial integrity. Post-IRI inflammation was strongly reduced in this group, particularly lymphocytes TCD4(+), PBR expression was influenced by IRI in the early period and during the development of chronic dysfunction. This study clearly shows that PEG has a beneficial effect in renal preservation and suggests a role of PBR as a marker IRI and repair processes.

  2. Peptide GE11-Polyethylene Glycol-Polyethylenimine for targeted gene delivery in laryngeal cancer.

    Science.gov (United States)

    Ren, Henglei; Zhou, Liang; Liu, Min; Lu, Weiyue; Gao, Chunli

    2015-07-01

    The objective of this study was to evaluate the possibility of using GE11-polyethylene glycol-polyethylenimine (GE11-PEG-PEI) for targeted gene delivery to treat epidermal growth factor receptor (EGFR)-overexpressing laryngeal cancer. This study described the design, characterization, and in vitro and in vivo study of the nanocarrier GE11-PEG-PEI for gene delivery to treat laryngeal cancer. Analysis of the sizes and zeta potentials indicated that the formation of PEGylated complexes was dependent on the N/P ratio, and these complexes were capable of binding plasmid DNA and condensing DNA into small positively charged nanoparticles. The results also revealed that GE11-PEG-PEI had a weaker effect on cell survival in vitro. Gene transfection was performed on human laryngeal cancer Hep-2 cells in vitro and in vivo. Both the in vitro and in vivo results demonstrated that GE11-PEG-PEI had greater transfection efficiency than mPEG-PEI. Compared with mPEG-PEI/pORF-hTRAIL and saline, GE11-PEG-PEI/pORFh-TRAIL significantly (p < 0.05) reduced tumor growth in nude mice with laryngeal cancer. Moreover, the GE11-PEG-PEI/pORF-hTRAIL-treated groups showed more apoptosis than the mPEG-PEI/pORF-hTRAIL-treated groups. Therefore, our results showed that the peptide GE11 conjugated to PEG-PEI delivered significantly more genes to EGFR-overexpressing laryngeal cancer cells in vivo, indicating that GE11-PEG-PEI may be a suitable gene vector for treating EGFR-overexpressing laryngeal cancer.

  3. Protopanaxadiol aglycone ginsenoside-polyethylene glycol conjugates: synthesis, physicochemical characterizations, and in vitro studies.

    Science.gov (United States)

    Mathiyalagan, Ramya; Kim, Yeon Ju; Wang, Chao; Jin, Yan; Subramaniyam, Sathiyamoorthy; Singh, Priyanka; Wang, Dandan; Yang, Deok Chun

    2016-12-01

    Ginsenosides are triterpenoid saponins, which is an active compound responsible for most of the pharmacological effects of ginseng (Panax ginseng Meyer). It is known to have numerous structural and pharmacological properties. However, aqueous solubility and delivery of ginsenosides in targeted region by avoiding undesirable toxicity to normal cell is also of prime importance. The aim of this study was to obtain amphiphilic ginsenoside derivatives in which hydrophilic polymers were conjugated to ginsenosides to enhance the water solubility and targeted delivery. To this end, the hydrophobic protopanaxadiol ginsenoside aglycone (aPPD) was covalently conjugated to the backbone of hydrophilic polyethylene glycol (PEG) through a pH sensitive ester linkage, which was confirmed by (1)H NMR and FTIR. The resultant PPD is covalently conjugated to hydrophilic PEG through esterification (PEG-PPD) forming self-assembled spherical nanoparticles, whose average particle diameter was 189 nm as observed by FE-TEM and particle size analyzer respectively. In vitro release experiments revealed that the release rate of PPD was rapidly increased from the self-assembled nanoparticles under acidic conditions (pH 5.0) than in a physiological buffer (pH 7.4) condition. Furthermore, in vitro cytotoxicity assays revealed that PEG-PPD conjugates exhibited lower cytotoxicity in HT-29 cancer cells compared with PPD alone. Since the slow release of PPD from conjugates is triggered only by acidic environmental conditions, such as those found in extracellular solid tumor tissues, intracellular endosomes, and intracellular lysosomes, the conjugation of PPD may aid its selective delivery to these targets. Overall, results suggest that pH-dependent release of PPD, which expected in reduced cytotoxicity to non-targeted regions, may enhance the overall efficacy of PPD.

  4. Enhanced detection of infectious hematopoietic necrosis virus by pretreatment of cell monolayers with polyethylene glycol

    Science.gov (United States)

    Batts, W.N.; Winton, J.R.

    1989-01-01

    To improve quantification of very low levels of infectious hematopoietic necrosis virus (IHNV) in samples of tissue, ovarian fluid, or natural water supplies, we tested the ability of polyethylene glycol (PEG) to enhance the sensitivity and speed of the plaque assay system. We compared 4, 7, and 10% solutions of PEG of molecular weight 6,000, 8,000, or 20,000 applied at selected volumes and for various durations. When cell monolayers of epithelioma papulosum cyprini (EPC), fathead minnow (FHM), chinook salmon embryo (CHSE-214), and bluegill fry (BF2) were pretreated with 7% PEG-20,000, they produced 4-17-fold increases in plaque assay titers of IHNV. The plaque assay titers of viral hemorrhagic septicemia virus, chum salmon reovirus, and chinook salmon paramyxovirus were also enhanced by exposure of CHSE-214 cells to PEG, but the titers of infectious pancreatic necrosis virus and Oncorhynchus masou virus were not substantially changed. Plaques formed by IHNV on PEG-treated EPC cells incubated at 15°C had a larger mean diameter at 6 d than those on control cells at 8 d; this suggests the assay could be shortened by use of PEG. Pretreatment of EPC cell monolayers with PEG enabled detection of IHNV in some samples that appeared negative with untreated cells. For example, when ovarian fluid samples from chinook salmon Oncorhynchus tshawytscha were inoculated onto untreated monolayers of EPC cells, IHNV was detected in only 11 of 51 samples; 17 of the samples were positive when PEG-treated EPC cells were used.PDF

  5. Enhanced dechlorination of tetrachloroethylene by zerovalent silicon in the presence of polyethylene glycol under anoxic conditions.

    Science.gov (United States)

    Lee, Chun-Chi; Doong, Ruey-An

    2011-03-15

    The combination of zerovalent silicon (Si(0)) with polyethylene glycol (PEG) is a novel technique to enhance the dechlorination efficiency and rate of chlorinated hydrocarbons. In this study, the dechlorination of tetrachloroethylene (PCE) by Si(0) in the presence of various concentrations of PEG was investigated under anoxic conditions. Several surfactants including cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Tween 80 were also selected for comparison. Addition of SDS and Tween 80 had little effect on the enhancement of PCE dechlorination, while CTAB and PEG significantly enhanced the dechlorination efficiency and rate of PCE by Si(0) under anoxic conditions. The Langmuir-Hinshelwood model was used to describe the dechlorination kinetics of PCE and could be simplified to pseudo-first-order kinetics at low PCE concentration. The rate constants (k(obs)) for PCE dechlorination were 0.21 and 0.36 h(-1) in the presence of CTAB and PEG, respectively. However, the reaction mechanisms for CTAB and PEG are different. CTAB could enhance the apparent water solubility of PCE in solution containing Si(0), leading to the enhancement of dechlorination efficiency and rate of PCE, while PEG prevented the formation of silicon dioxide, and significantly enhanced the dechlorination efficiency and rate of PCE at pH 8.3 ± 0.2. In addition, the dechlorination rate increased upon increasing PEG concentration and then leveled off to a plateau when the PEG concentration was higher than 0.2 μM. The k(obs) for PCE dechlorination by Si(0) in the presence of PEG was 106 times higher than that by Si(0) alone. Results obtained in this study would be helpful in facilitating the development of processes that could be useful for the enhanced degradation of cocontaminants by zerovalent silicon.

  6. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG-Induced Dehydration Stress in Cassava

    Directory of Open Access Journals (Sweden)

    Lili Fu

    2016-02-01

    Full Text Available Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG treatments. Five traits, including peroxidase (POD activity, proline content, malondialdehyde (MDA, soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment.

  7. No effect of covalently linked poly(ethylene glycol) chains on protein internal dynamics.

    Science.gov (United States)

    Gonnelli, Margherita; Strambini, Giovanni B

    2009-03-01

    Poly(ethylene glycol) or PEG is a hydrophilic polymer that covalently linked to therapeutical proteins may significantly increase their pharmacological properties. Despite the extensive production of PEG-conjugated proteins the effects of the polymer on the protein structure and dynamics is poorly understood, making the production of active biomaterials a largely unpredictable process. The present investigation examines the effects of 5 k and 20 k PEG on the internal flexibility of Ribonuclease T1, the mutant C112S of azurin from Pseudomonas aeruginosa, alcohol dehydrogenase and alkaline phosphatase, native and Zn-depleted. These systems encompass structural domains that range from rather superficial, flexible sites to deeply buried, rigid cores. The approach is based on three sensitive parameters related to the phosphorescence emission of internal Trp residues, namely, the intrinsic room-temperature phosphorescence lifetime (tau(0)) that reports on the local flexibility of the protein matrix around the chromophore and the bimolecular rate constant (k(q)) for the quenching of phosphorescence by O(2) and by acrylamide in solution, which are related to the diffusion of these solutes through the protein fold. The results obtained by these three independent, intrinsic probes of protein structure-dynamics concur that mono-PEGylation does not detectably perturb the conformation and dynamics of the protein native fold, over a wide temperature range. The implication is that protein motions are essentially not coupled to the polymer and that adverse effects of chemical modification on biological function are presumably owed to steric hindrance by PEG units blocking the access to sites critical for molecular recognition.

  8. Feasibility of poly(ethylene glycol) derivatives as diagnostic drug carriers for tumor imaging.

    Science.gov (United States)

    Kanazaki, Kengo; Sano, Kohei; Makino, Akira; Yamauchi, Fumio; Takahashi, Atsushi; Homma, Tsutomu; Ono, Masahiro; Saji, Hideo

    2016-03-28

    Poly(ethylene glycol) (PEG) is an artificial but biocompatible hydrophilic polymer that has been widely used in clinical products. To evaluate the feasibility of using PEG derivative itself as a tumor imaging carrier via an enhanced permeability and retention (EPR) effect, we prepared indium-111-labeled PEG ((111)In-DTPA-PEG) and indocyanine green (ICG)-labeled PEG (ICG-PEG) with PEG molecular weights of 5-40kDa and investigated their in vivo biodistribution in colon26 tumor-bearing mice. Thereafter, single-photon emission computed tomography (SPECT) and photoacoustic (PA) imaging studies were performed. The in vivo biodistribution studies demonstrated increased tumor uptake and a prolongation of circulation half-life as the molecular weight of PEG increased. Although the observed differences in in vivo biodistribution were dependent on the labeling method ((111)In or ICG), the tumor-to-normal tissue ratios were comparable. Because PEG-based probes with a molecular weight of 20kDa (PEG20) showed a preferable biodistribution (highest accumulation among tissues excised and relatively high tumor-to-blood ratios), an imaging study using (111)In-DTPA-PEG20 and ICG-PEG20 was performed. Colon26 tumors inoculated in the right shoulder were clearly visualized by SPECT 24h after administration. Furthermore, PA imaging using ICG-PEG20 also detected tumor regions, and the detected PA signals increased in proportion with the injected dose. These results suggest that PEG derivatives (20kDa) serve as robust diagnostic drug carriers for tumor imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Development of poly(ethylene glycol) hydrogels for salivary gland tissue engineering applications.

    Science.gov (United States)

    Shubin, Andrew D; Felong, Timothy J; Graunke, Dean; Ovitt, Catherine E; Benoit, Danielle S W

    2015-06-01

    More than 40,000 patients are diagnosed with head and neck cancers annually in the United States with the vast majority receiving radiation therapy. Salivary glands are irreparably damaged by radiation therapy resulting in xerostomia, which severely affects patient quality of life. Cell-based therapies have shown some promise in mouse models of radiation-induced xerostomia, but they suffer from insufficient and inconsistent gland regeneration and accompanying secretory function. To aid in the development of regenerative therapies, poly(ethylene glycol) hydrogels were investigated for the encapsulation of primary submandibular gland (SMG) cells for tissue engineering applications. Different methods of hydrogel formation and cell preparation were examined to identify cytocompatible encapsulation conditions for SMG cells. Cell viability was much higher after thiol-ene polymerizations compared with conventional methacrylate polymerizations due to reduced membrane peroxidation and intracellular reactive oxygen species formation. In addition, the formation of multicellular microspheres before encapsulation maximized cell-cell contacts and increased viability of SMG cells over 14-day culture periods. Thiol-ene hydrogel-encapsulated microspheres also promoted SMG proliferation. Lineage tracing was employed to determine the cellular composition of hydrogel-encapsulated microspheres using markers for acinar (Mist1) and duct (Keratin5) cells. Our findings indicate that both acinar and duct cell phenotypes are present throughout the 14 day culture period. However, the acinar:duct cell ratios are reduced over time, likely due to duct cell proliferation. Altogether, permissive encapsulation methods for primary SMG cells have been identified that promote cell viability, proliferation, and maintenance of differentiated salivary gland cell phenotypes, which allows for translation of this approach for salivary gland tissue engineering applications.

  10. Prospective evaluation of 1-day polyethylene glycol-3350 bowel preparation regimen in children.

    Science.gov (United States)

    Abbas, Mazen I; Nylund, Cade M; Bruch, Carol J; Nazareno, Luzviminda G; Rogers, Philip L

    2013-02-01

    The aim of the present study was to evaluate efficacy, safety, and tolerability of a pediatric colonoscopy bowel preparation regimen composed of polyethylene glycol-3350 (PEG-3350) and a sports drink completed in a few hours. A prospective, open-label trial of a colonoscopy bowel preparation in children ages 8 to 18 years that included 238 g of PEG-3350 mixed with 1.9 L of Gatorade completed in a few hours. Efficacy was determined using the Boston Bowel Preparation Scale. Basic metabolic profiles and questionnaires were obtained that assessed for safety, adverse effects, tolerability, and patient acceptability. Forty-six patients completed the study. Patients were predominately boys (56.5%) with a mean age of 14.50 years (SD ± 2.9 years). Forty-three (93.5%) were able to complete the regimen. All of the colonoscopies were completed to the cecum and 84% had terminal ileum visualization. Seventy-seven percent were found to be effective preparations. Nausea/vomiting were the most common reported adverse effect (60%) followed by abdominal pain/cramping (44%) and fatigue/weakness (40%). Overall, the regimen was acceptable with 1 exception being the large volume to drink. There were no clinically significant changes in basic metabolic profiles, although there was a statistically significant decrease in the mean potassium (0.16 mEq/L; P = 0.016), blood urea nitrogen (2.68 mg/dL; P Gatorade administered in a few hours is an effective, safe, and moderately tolerable bowel preparation regimen for colonoscopy in children.

  11. Inner ear delivery of dexamethasone using injectable silk-polyethylene glycol (PEG) hydrogel.

    Science.gov (United States)

    Yu, Dehong; Sun, Changling; Zheng, Zhaozhu; Wang, Xueling; Chen, Dongye; Wu, Hao; Wang, Xiaoqin; Shi, Fuxin

    2016-04-30

    Minimally invasive delivery and sustained release of therapeutics to the inner ear are of importance to the medical treatment of inner ear disease. In this study, the injectable silk fibroin-polyethylene glycol (Silk-PEG) hydrogel was investigated as a drug delivery carrier to deliver poorly soluble micronized dexamethasone (mDEX) to the inner ear of guinea pigs. Encapsulation of mDEX with a loading up to 5% (w/v) did not significantly change the silk gelation time, and mDEX were evenly distributed in the PEG-Silk hydrogel as visualized by SEM. The loading of mDEX in Silk-PEG hydrogel largely influenced in vitro drug release kinetics. The optimized Silk-PEG-mDEX hydrogel (2.5% w/v loading, in situ-forming, 10 μl) was administered directly onto the round window membrane of guinea pigs. The DEX concentration in perilymph maintained above 100 ng/ml for at least 10 days for the Silk-PEG formulation while less than 12h for the control sample of free mDEX. Minimal systemic exposure was achieved with low DEX concentrations (Silk-PEG-mDEX hydrogel. A transient hearing threshold shift was found but then resolved after 14 days as revealed by auditory brainstem response (ABR), showing minimal inflammatory responses on the round window membrane and scala taympani. The Silk-PEG hydrogel completely degraded in 21 days. Thus, the injectable PEG-Silk hydrogel is an effective and safe vehicle for inner ear delivery and sustained release of glucocorticoid.

  12. Thermoacoustical analysis of solutions of poly(ethylene glycol) 200 through H-bond complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Yasmin, Maimoona, E-mail: myasmin908@gmail.com [Department of Physics, University of Lucknow, Lucknow 226007 (India); Gupta, Manisha, E-mail: guptagm@rediffmail.com [Department of Physics, University of Lucknow, Lucknow 226007 (India)

    2011-05-10

    Research highlights: {yields} The presence of two electronegative elements viz. nitrogen and oxygen in its molecular architecture, ethanolamine has greater extent of interaction with PEG. {yields} Ethanolamine and m-cresol may be involved in a complex type of network of hydrogen bonding. {yields} Ethanolamine has greater extent of interaction with PEG than m-cresol and aniline particularly with least magnitude from aniline, where electron availability is least because of delocalization. {yields} The difference in molar volume between the components of the mixture control the mixture properties. - Abstract: Densities ({rho}) and ultrasonic velocities (u) of binary mixtures of poly(ethylene glycol) 200, PEG, with ethanolamine, m-cresol and aniline have been measured at various concentrations at 293.15, 303.15 and 313.15 K and have been fitted by third order polynomial equations at each temperature. The calculated values of isentropic compressibility (k{sub s}), free volume (V{sub f}), internal pressure ({pi}{sub i}), relaxation time ({tau}) and surface tension ({sigma}) at different mole fractions of PEG have been used to explain the hydrogen bonding and intermolecular interactions present in the mixture. Using these data, excess molar volume (V{sup E}), excess intermolecular free length (L{sub f}{sup E}), excess acoustic impedance (Z{sup E}) and excess pseudo-Grueneisen parameter ({Gamma}{sup E}) have been calculated and the results have been fitted to Redlich-Kister polynomial equation. All the results support each other and help in understanding the interactions in the mixture. Various models and mixing rules have been applied to evaluate the ultrasonic velocity data and have been compared with the experimental results.

  13. Growth of sheep fed tannin-rich Albizia gummifera with or without polyethylene glycol.

    Science.gov (United States)

    Yisehak, Kechero; Biruk, Kebede; Abegaze, Beyene; Janssens, Geert P J

    2014-10-01

    Twenty-four intact male Bonga lambs were studied in a 100-day experiment to evaluate the effect of feeding tannin rich leaves of Albizia gummifera (AG) on nutrient utilization, growth performance, and carcass composition. The dietary treatments consisted of hay alone (T1, control), AG at 30 % of control diet + T1 (T2), and T2 + polyethylene glycol 6000 (PEG) (T3, 40 mg PEG, 1 kg AG/head on a dry mass (DM) basis. The lambs were individually fed at 50 g DM/kg live weight. In the last 10 days of the experiment, all animals from each treatment were harnessed with feces collection bags. At the end of the experiment, lambs were slaughtered after overnight fasting for measurements of carcass characteristics. Crude protein, neutral detergent fiber, and condensed tannin contents of AG were 300, 586, and 108 g/kg DM, respectively. Lambs fed AG with PEG had higher (P < 0.001) feed intake, digestibility, carcass weight, and weight gain compared with other treatments. Although lambs fed diet T2 were able to utilize AG, the efficiency of its utilization was lower (P < 0.001) than the PEG-treated groups. The improvement in nutrient intake and digestibility, carcass weight, and growth performance of lambs supplemented with PEG emphasizes the negative effect of tannins on livestock performance. Leaves of AG enhance digestibility and performance in tropical hay-fed sheep, and the addition of PEG further improves this effect, likely due to the binding of tannins.

  14. Online Aerosol Mass Spectrometry of Single Micrometer-Sized Particles Containing Poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Bogan, M J; Patton, E; Srivastava, A; Martin, S; Fergenson, D; Steele, P; Tobias, H; Gard, E; Frank, M

    2006-10-25

    Analysis of poly(ethylene glycol)(PEG)-containing particles by online single particle aerosol mass spectrometers equipped with laser desorption ionization (LDI) is reported. We demonstrate that PEG-containing particles are useful in the development of aerosol mass spectrometers because of their ease of preparation, low cost, and inherently recognizable mass spectra. Solutions containing millimolar quantities of PEGs were nebulized and, after drying, the resultant micrometer-sized PEG containing particles were sampled. LDI (266 nm) of particles containing NaCl and PEG molecules of average molecular weight <500 generated mass spectra reminiscent of mass spectra of PEG collected by other MS schemes including the characteristic distribution of positive ions (Na{sup +} adducts) separated by the 44 Da of the ethylene oxide units separating each degree of polymerization. PEGs of average molecular weight >500 were detected from particles that also contained t the tripeptide tyrosine-tyrosine-tyrosine or 2,5-dihydroxybenzoic acid, which were added to nebulized solutions to act as matrices to assist LDI using pulsed 266 nm and 355 nm lasers, respectively. Experiments were performed on two aerosol mass spectrometers, one reflectron and one linear, that each utilize two time-of-flight mass analyzers to detect positive and negative ions created from a single particle. PEG-containing particles are currently being employed in the optimization of our bioaerosol mass spectrometers for the application of measurements of complex biological samples, including human effluents, and we recommend that the same strategies will be of great utility to the development of any online aerosol LDI mass spectrometer platform.

  15. Hierarchically designed agarose and poly(ethylene glycol) interpenetrating network hydrogels for cartilage tissue engineering.

    Science.gov (United States)

    DeKosky, Brandon J; Dormer, Nathan H; Ingavle, Ganesh C; Roatch, Christopher H; Lomakin, Joseph; Detamore, Michael S; Gehrke, Stevin H

    2010-12-01

    A new method for encapsulating cells in interpenetrating network (IPN) hydrogels of superior mechanical integrity was developed. In this study, two biocompatible materials-agarose and poly(ethylene glycol) (PEG) diacrylate-were combined to create a new IPN hydrogel with greatly enhanced mechanical performance. Unconfined compression of hydrogel samples revealed that the IPN displayed a fourfold increase in shear modulus relative to a pure PEG-diacrylate network (39.9 vs. 9.9 kPa) and a 4.9-fold increase relative to a pure agarose network (8.2 kPa). PEG and IPN compressive failure strains were found to be 71% ± 17% and 74% ± 17%, respectively, while pure agarose gels failed around 15% strain. Similar mechanical property improvements were seen when IPNs-encapsulated chondrocytes, and LIVE/DEAD cell viability assays demonstrated that cells survived the IPN encapsulation process. The majority of IPN-encapsulated chondrocytes remained viable 1 week postencapsulation, and chondrocytes exhibited glycosaminoglycan synthesis comparable to that of agarose-encapsulated chondrocytes at 3 weeks postencapsulation. The introduction of a new method for encapsulating cells in a hydrogel with enhanced mechanical performance is a promising step toward cartilage defect repair. This method can be applied to fabricate a broad variety of cell-based IPNs by varying monomers and polymers in type and concentration and by adding functional groups such as degradable sequences or cell adhesion groups. Further, this technology may be applicable in other cell-based applications where mechanical integrity of cell-containing hydrogels is of great importance.

  16. Antifibrotic effect of rapamycin containing polyethylene glycol-coated alginate microcapsule in islet xenotransplantation.

    Science.gov (United States)

    Park, Heon-Seok; Kim, Ji-Won; Lee, Seung-Hwan; Yang, Hae Kyung; Ham, Dong-Sik; Sun, Cheng-Lin; Hong, Tae Ho; Khang, Gilson; Park, Chung-Gyu; Yoon, Kun-Ho

    2017-04-01

    Islet microencapsulation is an attractive strategy for the minimization or avoidance of life-long immunosuppression after transplantation. However, the clinical implementation of this technique is currently limited by incomplete biocompatibility. Thus, the aim of the present study was to demonstrate the improved biocompatibility of rapamycin-containing polyethylene glycol (Rapa-PEG)-coating on alginate microcapsules containing xenogeneic islets. The Rapa-PEG-coating on the alginate layer was observed using scanning electron microscopy (SEM) and the molecular cut-off weight of the microcapsules was approximately 70 kDa. The viabilities of the alginate-encapsulated and Rapa-PEG-coated alginate-encapsulated islets were lower than the viability of the naked islets just after encapsulation, but these the differences diminished over time in culture dishes. Rapa-PEG-coating on the alginate capsules effectively decreased the proliferation of macrophage cells compared to the non-coating and alginate coating of xenogeneic pancreas tissues. Glucose-stimulated insulin secretion did not significantly differ among the groups prior to transplantation. The random blood glucose levels of diabetic mice significantly improved following the transplantation of alginate-encapsulated and Rapa-PEG-coated alginate-encapsulated islets, but there were no significant differences between these two groups. However, there was a significant decrease in the number of microcapsules with fibrotic cell infiltration in the Rapa-PEG-coated alginate microcapsule group compared to the alginate microcapsule group. In conclusion, Rapa-PEG-coating might be an effective technique with which to improve the biocompatibility of microcapsules containing xenogeneic islets. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  17. Fabrication of Off-the-Shelf Multilumen Poly(Ethylene Glycol) Nerve Guidance Conduits Using Stereolithography.

    Science.gov (United States)

    Arcaute, Karina; Mann, Brenda K; Wicker, Ryan B

    2011-01-01

    A manufacturing process for fabricating off-the-shelf multilumen poly(ethylene glycol) (PEG)-based nerve guidance conduits (NGCs) was developed that included the use of stereolithography (SL). A rapid fabrication strategy for complex 3D scaffolds incorporated postprocessing with lyophilization and sterilization to preserve the scaffold, creating an implantable product with improved suturability. SL is easily adaptable to changes in scaffold design, is compatible with various materials and cells, and can be expanded for mass manufacture. The fabricated conduits were characterized using optical and scanning electron microscopy, and measurements of swelling ratio, dimensional swelling factor, resistance to compression, and coefficient of friction were performed. Water absorption curves showed that the conduits after lyophilization and sterilization return easily and rapidly to a swollen state when placed in an aqueous solution, successfully maintaining their original overall structure as required for implantation. Postprocessed conduits at the swollen state were less slippery and therefore easier to handle than those without postprocessing. Suture pullout experiments showed that NGCs fabricated with a higher concentration of PEG were better able to resist suture pullout. NGCs having a multilumen design demonstrated a better resistance to compression than a single-lumen design with an equivalent surface area, as well as a greater force required to collapse the design. Conduits fabricated with a higher PEG concentration were shown to have compressive resistances comparable to those of commercially available NGCs. The use of SL with PEG and the manufacturing process developed here shows promise for improving the current state of the art in peripheral nerve repair strategies.

  18. Polyethylene glycol (PEG)-Poly(N-isopropylacrylamide) (PNIPAAm) based thermosensitive injectable hydrogels for biomedical applications.

    Science.gov (United States)

    Alexander, Amit; Ajazuddin; Khan, Junaid; Saraf, Swarnlata; Saraf, Shailendra

    2014-11-01

    Protein and peptide delivery by the use of stimuli triggered polymers remains to be the area of interest among the scientist and innovators. In-situ forming gel for the parenteral route in the form of hydrogel and implants are being utilized for various biomedical applications. The formulation of gel depends upon factors such as temperature modulation, pH changes, the presence of ions and ultra-violet irradiation, from which drug is released in a sustained and controlled manner. Among various stimuli triggered factors, thermoresponsive is the most potential one for the delivery of protein and peptides. Poly(ethylene glycol) (PEG) based copolymers play a crucial role as a biomedical material for biomedical applications, because of its biocompatibility, biodegradability, thermosensitivity and easy controlled characters. This review, stresses on the physicochemical property, stability and compositions prospects of smart thermoresponsive polymer specifically, PEG/Poly(N-isopropylacrylamide) (PNIPAAm) based thermoresponsive injectable hydrogels, recently utilized for biomedical applications. PEG-PNIPAAm based hydrogel exhibits good gelling mechanical strength and minimizes the initial burst effect of the drug. In addition, upon changing the composition and proportion of the copolymer molecular weight and ratio, the gelling time can be reduced to a great extent providing better sol-gel transition. The hydrogel formed by the same is able to release the drug over a long duration of time, meanwhile is also biocompatible and biodegradable. Manuscript will give the new researchers an idea about the potential and benefits of PNIPAAm based thermoresponsive hydrogels for the biomedical application. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Partitioning of alcohol ethoxylates and polyethylene glycols in the marine environment: Field samplings vs laboratory experiments

    Energy Technology Data Exchange (ETDEWEB)

    Traverso-Soto, Juan M. [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain); Brownawell, Bruce J. [School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000 (United States); González-Mazo, Eduardo [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain); Lara-Martín, Pablo A., E-mail: pablo.lara@uca.es [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain)

    2014-08-15

    Nowadays, alcohol ethoxylates (AEOs) constitute the most important group of non-ionic surfactants, used in a wide range of applications such as household cleaners and detergents. Significant amounts of these compounds and their degradation products (polyethylene glycols, PEGs, which are also used for many other applications) reach aquatic environments, and are eliminated from the water column by degradation and sorption processes. This work deals with the environmental distribution of AEOs and PEGs in the Long Island Sound Estuary, a setting impacted by sewage discharges from New York City (NYC). The distribution of target compounds in seawater was influenced by tides, consistent with salinity differences, and concentrations in suspended solid samples ranged from 1.5 to 20.5 μg/g. The more hydrophobic AEOs were mostly attached to the particulate matter whereas the more polar PEGs were predominant in the dissolved form. Later, the sorption of these chemicals was characterized in the laboratory. Experimental and environmental sorption coefficients for AEOs and PEGs showed average values from 3607 to 164,994 L/kg and from 74 to 32,862 L/kg, respectively. The sorption data were fitted to a Freundlich isotherm model with parameters n and log K{sub F} between 0.8–1.2 and 1.46–4.39 L/kg, respectively. AEO and PEG sorptions on marine sediment were also found to be mostly not affected by changes in salinity. - Highlights: • AEO and PEG levels in estuaries are influenced by tides and suspended solids. • Sediment–water partition coefficients in the lab and in the field are comparable. • Sorption is depending on both hydrophilic and hydrophobic interactions. • Sorption data fits Freundlich isotherms, showing K{sub F} values from 29 to 24,892 L/kg. • Sorption is very weakly influenced by salinity changes.

  20. Detection of poly(ethylene glycol) residues from nonionic surfactants in surface water by1h and13c nuclear magnetic resonance spectrometry

    Science.gov (United States)

    Leenheer, J.A.; Wershaw, R. L.; Brown, P.A.; Noyes, T.I.

    1991-01-01

    ??? Poly(ethylene glycol) (PEG) residues were detected in organic solute isolates from surface water by 1H nuclear magnetic resonance spectrometry (NMR), 13C NMR spectrometry, and colorimetric assay. PEG residues were separated from natural organic solutes in Clear Creek, CO, by a combination of methylation and chromatographic procedures. The isolated PEG residues, characterized by NMR spectrometry, were found to consist of neutral and acidic residues that also contained poly(propylene glycol) moieties. The 1H NMR and the colorimetric assays for poly(ethylene glycol) residues were done on samples collected in the lower Mississippi River and tributaries between St. Louis, MO, and New Orleans, LA, in July-August and November-December 1987. Aqueous concentrations for poly(ethylene glycol) residues based on colorimetric assay ranged from undetectable to ???28 ??g/L. Concentrations based on 1H NMR spectrometry ranged from undetectable to 145 ??g/L.

  1. Curcumin Encapsulated into Methoxy Poly(Ethylene Glycol) Poly(ε-Caprolactone) Nanoparticles Increases Cellular Uptake and Neuroprotective Effect in Glioma Cells.

    Science.gov (United States)

    Marslin, Gregory; Sarmento, Bruno Filipe Carmelino Cardoso; Franklin, Gregory; Martins, José Alberto Ribeiro; Silva, Carlos Jorge Ribeiro; Gomes, Andreia Ferreira Castro; Sárria, Marisa Passos; Coutinho, Olga Maria Fernandes Pereira; Dias, Alberto Carlos Pires

    2017-03-01

    Curcumin is a natural polyphenolic compound isolated from turmeric (Curcuma longa) with well-demonstrated neuroprotective and anticancer activities. Although curcumin is safe even at high doses in humans, it exhibits poor bioavailability, mainly due to poor absorption, fast metabolism, and rapid systemic elimination. To overcome these issues, several approaches, such as nanoparticle-mediated targeted delivery, have been undertaken with different degrees of success. The present study was conducted to compare the neuroprotective effect of curcumin encapsulated in poly(ε-caprolactone) and methoxy poly(ethylene glycol) poly(ε-caprolactone) nanoparticles in U251 glioblastoma cells. Prepared nanoparticles were physically characterized by laser doppler anemometry, transmission electron microscopy, and X-ray diffraction. The results from laser doppler anemometry confirmed that the size of poly(ε-caprolactone) and poly(ethylene glycol) poly(ε-caprolactone) nanoparticles ranged between 200-240 nm for poly(ε-caprolactone) nanoparticles and 30-70 nm for poly(ethylene glycol) poly(ε-caprolactone) nanoparticles, and transmission electron microscopy images revealed their spherical shape. Treatment of U251 glioma cells and zebrafish embryos with poly(ε-caprolactone) and poly(ethylene glycol) poly(ε-caprolactone) nanoparticles loaded with curcumin revealed efficient cellular uptake. The cellular uptake of poly(ethylene glycol) poly(ε-caprolactone) nanoparticles was higher in comparison to poly(ε-caprolactone) nanoparticles. Moreover, poly(ethylene glycol) poly(ε-caprolactone) di-block copolymer-loaded curcumin nanoparticles were able to protect the glioma cells against tBHP induced-oxidative damage better than free curcumin. Together, our results show that curcumin-loaded poly(ethylene glycol) poly(ε-caprolactone) di-block copolymer nanoparticles possess significantly stronger neuroprotective effect in U251 human glioma cells compared to free curcumin and curcumin

  2. Effect of temperature and aging time on the rheological behavior of aqueous poly(ethylene glycol)/Laponite RD dispersions.

    Science.gov (United States)

    Morariu, Simona; Bercea, Maria

    2012-01-12

    The viscoelastic properties of 2% poly(ethylene glycol) aqueous solutions containing Laponite RD from 1% to 4% were investigated by oscillatory and flow measurements in the temperature range of 15-40 °C. The enhancement of the clay content from mixture causes the increase of the viscoelastic moduli and the change of the flow from liquid-like behavior (Maxwellian fluid) to a solid-like one at a set temperature. The longest relaxation times (τ(1)) of the mixtures with low clay concentrations (1% and 2%) are not affected by changes in temperature unlike the samples having high content of clay at which τ(1) increases above 30 °C and below 17.5 °C. The characteristic behavior of the mixtures with the high clay concentration could be explained by considering the effect of Brownian motion on the network structure formed in these dispersions as well as by the poor solubility of poly(ethylene glycol) in water at high temperatures. The flow activation energy was determined and discussed. An abrupt increase of the flow activation energy was evidenced between 2% and 3% Laponite RD. The rheological measurements carried out at different rest times showed a decrease of the gelation time from 1 week to 2 h when the clay concentration increases from 2% to 4%. The aging kinetics of poly(ethylene glycol)/Laponite RD/water mixtures, investigated at 25 °C, revealed the increase of the viscosity-rate kinetic constant by increasing the clay concentration.

  3. Preparation and properties of polyrotaxane from -cyclodextrin and poly(ethylene glycol) with poly(vinyl alcohol)

    Indian Academy of Sciences (India)

    Mohammad Ali Semsarzadeh; Sahar Amiri

    2013-11-01

    –Cyclodextrin (-CD) was found to form inclusion complexes with poly(ethylene glycol) (PEG) having a crystalline state in high yields, which have been investigated extensively in the past. Formation of an inclusion complex depends strongly on structure, molecular weight and geometry of the polymer. Development of a dicomponent inclusion complex (DIC) of PEG and -CD in the presence of poly(vinyl alcohol) (PVA) and initiation of hexagonal crystals upon sonication have exhibited various microstructures. Formation of the new inclusion complex in PVA heavily depends on the concentration of PVA, temperature and sonication time. The complexes produced are characterized by FTIR, HNMR spectra and powder X-ray. 1HNMR of the complexes demonstrate that their stoichiometric ratio is 2:1 (two ethylene glycol units and one -CD). X-ray patterns of PEG–-CD complex indicate that the -CD forms channels whereas PEG/-CD/PVA creates cage-type structures.

  4. The study of The study of the influence of temperature on surfactants – polyethylene glycol layers The study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface liquid-gas interfacethe influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interfaceThe study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface

    Directory of Open Access Journals (Sweden)

    Seryk Boloshaan

    2015-03-01

    Full Text Available The surface tension of compositions consisting of nonionic polyethylene glycol and surface active substances of different nature and influence of temperatures on properties of their adsorption layers were studied. To be taken into account the basics of classical chemical thermodynamics and colloidal chemistry, the thermodynamic parameters were determined for the adsorption of glycol, cetyl pyridinium bromide, Tween- 80 and sodium dodecyl sulfate. Adsorption speed was valuated By Kinetic curves of a liquid /gas interfaces. As a surfactants were taken the anionic surfactant – sodium dodecylsulphate, cationic surfactant cetylpyridinium bromide and nonionic Tween-80. The reason of using nonionic polyethyleneglycol as polymer is that the polymer is not toxic, biodegradable and it has no harm to the human body. That is why they are largely used in food industry, pharmaceutics, cosmetics and household chemical products.

  5. Non-invasive control of influence of polyethylene glycol on transport function of fluorescent colored liposomal nanoparticles

    Science.gov (United States)

    Stelmashchuk, O.; Zherebtsov, E.; Zherebtsova, A.; Kuznetsova, E.; Vinokurov, A.; Dunaev, A.; Mamoshin, A.; Snimshchikova, I.; Borsukov, A.; Bykov, A.; Meglinski, I.

    2017-03-01

    The studies were carried out on groups of clinically healthy mice line of outbred CD-1 stock. The model animals were divided into 2 groups and received experimental liposomal formulations. Using the method of fluorescence spectroscopy, we investigated the effectiveness of penetration into the circulatory system of fluorescently stained liposomes with polyethylene glycol (PEG) and without PEG when administered orally. Fluorescence channel with a fiber probe series of multifunctional laser non-invasive diagnostic system "LAKK-M" (SPE "LAZMA" Ltd, Russia) was used as the measuring equipment.

  6. Polyethylene glycol-induced internalization of bacteria into fungal protoplasts: Electron microscopic study and optimization of experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Guerra-Tschuschke, I.; Martin, I.; Gonzalez, M.T. (Univ. de Granada, (Spain))

    1991-05-01

    The authors studied the mechanism of internalization of Escherichia coli into Saccharomyces cerevisiae induced by polyethylene glycol (PEG) and optimized the experimental conditions. Transmission electron microscope studies revealed that the principal factor involved in the internalization was the degree of cell aggregation attained. Internalization occurred mainly by an endocytosis-like mechanism and took place during the elimination of PEG. The optimum conditions were to treat a mixed pellet of both microorganisms with 15% PEG and then gradually dilute the polymer. The same conditions were applied to E. coli and Aspergillus nidulans, with similar results.

  7. Thermodynamic modelling of phase equilibrium for water + poly(Ethylene glycol + salt aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    R.A.G. Sé

    2002-04-01

    Full Text Available The NRTL (nonrandom, two-liquid model, expressed in mass fraction instead of mole fraction, was used to correlate liquid-liquid equilibria for aqueous two-phase polymer-salt solutions. New interaction energy parameters for this model were determined using reported data on the water + poly(ethylene glycol + salt systems, with different molecular masses for PEG and the salts potassium phosphate, sodium sulfate, sodium carbonate and magnesium sulfate. The correlation of liquid-liquid equilibrium is quite satisfactory.

  8. Chitosan grafted methoxy poly(ethylene glycol)-poly(ε-caprolactone) nanosuspension for ocular delivery of hydrophobic diclofenac

    OpenAIRE

    Shuai Shi; Zhaoliang Zhang; Zichao Luo; Jing Yu; Renlong Liang; Xingyi Li; Hao Chen

    2015-01-01

    This study aimed to develop a cationic nanosuspension of chitosan (CS) and methoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL) for ocular delivery of diclofenac (DIC). MPEG-PCL-CS block polymer was synthesized by covalent coupling of MPEG-PCL with CS. The critical micelle concentration of the MPEG-PCL-CS block polymer was 0.000692 g/L. DIC/MPEG-PCL-CS nanosuspension (mean particle size = 105 nm, zeta potential = 8 mV) was prepared and characterized by Fourier transform infrared spec...

  9. Synthesis of Monodispersed Gold Nanoparticles with Exceptional Colloidal Stability with Grafted Polyethylene Glycol-g-polyvinyl Alcohol

    Directory of Open Access Journals (Sweden)

    Alaaldin M. Alkilany

    2015-01-01

    Full Text Available Herein, we report the synthesis of spherical gold nanoparticles with tunable core size (23–79 nm in the presence of polyethylene glycol-g-polyvinyl alcohol (PEG-g-PVA grafted copolymer as a reducing, capping, and stabilizing agent in a one-step protocol. The resulted PEG-g-PVA-capped gold nanoparticles are monodispersed with an exceptional colloidal stability against salt addition, repeated centrifugation, and extensive dialysis. The effect of various synthesis parameters and the kinetic/mechanism of the nanoparticle formation are discussed.

  10. Plasma graft of poly(ethylene glycol) methyl ether methacrylate (PEGMA) on RGP lens surface for reducing protein adsorption

    Science.gov (United States)

    Shiheng, Yin; Li, Ren; Yingjun, Wang

    2017-01-01

    Poly(ethylene glycol) methyl ether methacrylate (PEGMA) was grafted on fluorosilicone acrylate rigid gas permissible contact lens surface by means of argon plasma induced polymerization to improve surface hydrophilicity and reduce protein adsorption. The surface properties were characterized by contact angle measurement, x-ray photoelectron spectroscopy (XPS) and atomic force microscopy respectively. The surface protein adsorption was evaluated by lysozyme solution immersion and XPS analysis. The results indicated that a thin layer of PEGMA was successfully grafted. The surface hydrophilicity was bettered and surface free energy increased. The lysozyme adsorption on the lens surface was reduced greatly. The study was supported by National Natural Science Foundation of China (No. 51273072).

  11. Recovery of endo-polygalacturonase using polyethylene glycol-salt aqueous two-phase extraction with polymer recycling

    OpenAIRE

    Wu, You-Ting; Pereira, Martinha; Venâncio, Armando; Teixeira, J. A.

    2000-01-01

    The partitioning behaviour of endo-polygalacturonase (endo-PG) and total protein from a clarified Kluyveromyces marxianus fermentation broth in polyethylene glycol (PEG)-ammonium sulfate and PEG-potassium phosphate (pH=7) aqueous two-phase systems was experimentally investigated. Both the enzyme and total protein partitioned in the bottom phase for these two kinds of systems. The enzyme partitioning coefficient can be lower than 0.01 in PEG8000-(NH4)2SO4 ATPS with a large phase volume ratio a...

  12. Novel solid – solid phase change material based on polyethylene glycol and cellulose used for temperature stabilisation

    Directory of Open Access Journals (Sweden)

    Wojda Marta

    2014-01-01

    Full Text Available Thermal management is one of crucial issues in the development of modern electronic devices. In the recent years interest in phase change materials (PCMs as alternative cooling possibility has increased significantly. Preliminary results concerning the research into possibility of the use of solid-solid phase change materials (S-S PCMs for stabilisation temperature of electronic devices has been presented in the paper. Novel solid-solid phase change material based on polyethylene glycol and cellulose has been synthesized. Attempt to improve its thermal conductivity has been taken. Material has been synthesized for the purpose of stabilisation of temperature of electronic devices.

  13. Partition Coefficients of Amino Acids, Peptides, and Enzymes in Dextran + Poly(Ethylene Glycol) + Water Aqueous Two-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kakisaka, Keijiro.; Shindo, Takashi.; Iwai, Yoshio.; Arai, Yasuhiko. (Kyushu University, Fukuoka (Japan). Department of Chemical Systems and Engineering)

    1998-12-01

    Partition coefficients are measured for five amino acids(aspartic acid, asparagine, methionine, cysteine and histidine) and tow peptides(glycyl-glycine and hexa-glycine) in dextran + poly(ethylene glycol) + water aqueous two-phase system. The partition coefficients of the amino acids and peptides are aorrelated using the osmotic virial equation. The interaction coefficients contained in the equation can be calculated by hydrophilic group parameters. The partition coefficients of [alpha]-amylase calculated by the osmotic virial equation with the hydrophilic group parameters are in fairly good agreement with the experimental data, though a relatively large discrepancy is shown for [beta]-amylase. (author)

  14. Partition Coefficients of Amino Acids, Peptides, and Enzymes in Dextran + Poly(Ethylene Glycol) + Water Aqueous Two-Phase Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kakisaka, Keijiro.; Shindo, Takashi.; Iwai, Yoshio.; Arai, Yasuhiko. [Kyushu University, Fukuoka (Japan). Department of Chemical Systems and Engineering

    1998-12-01

    Partition coefficients are measured for five amino acids(aspartic acid, asparagine, methionine, cysteine and histidine) and tow peptides(glycyl-glycine and hexa-glycine) in dextran + poly(ethylene glycol) + water aqueous two-phase system. The partition coefficients of the amino acids and peptides are aorrelated using the osmotic virial equation. The interaction coefficients contained in the equation can be calculated by hydrophilic group parameters. The partition coefficients of {alpha}-amylase calculated by the osmotic virial equation with the hydrophilic group parameters are in fairly good agreement with the experimental data, though a relatively large discrepancy is shown for {beta}-amylase. (author)

  15. Mechanical properties of polyurethane film exposed to solutions of nonoxynol-9 surfactant and polyethylene glycol

    Science.gov (United States)

    McDermott, Martin Kendrick

    Changes in physical properties (tensile strength, strain to failure, elastic modulus, diffusion kinetics and soft segment glass transition temperature (Tg)) were examined for polyetherurethane block copolymers Estane and Tecoflex. These polymer chains consist of 2 mutually incompatible blocks or segments which form microphases consisting of rigid/hard segments in an elastomeric matrix of soft segments. The polyurethanes were exposed to mixtures of nonoxynol 9 (N9) surfactant in polyethylene glycol 400 (PEG) at various concentrations and for various times. The purpose was to estimate the effect of exposure to mixtures of N9 spermicide and PEG lubricant on breakage of condoms made from films of these elastomers. Mechanical properties of Estane varied with direction because of molecular orientation induced during manufacturing, suggesting that condoms should be cut from the film in a way that optimizes this property-orientation relationship. Large amounts of N9 were absorbed from N9/PEG solutions. The polymer fraction of the swollen Estane film versus soak solution composition did not follow a linear rule of mixtures. As the percentage of N9 in the PEG/N9 soak solution increased, Estane absorbed more liquid and its properties decreased more than did Tecoflex. This may not matter for low concentrations of N9 where the mechanical properties of Estane were superior to those of Tecoflex. The loss of mechanical properties with increased N9 concentration was likely due to plasticization of the soft segment domains. Hard segment domain disruption was probably not occurring because the relationship between the elastic modulus and polymer volume fraction followed the Flory-Rehner relationship for swollen elastic rubber networks and diffusion of neat N9 and neat PEG followed a Fickian behavior. This is expected because hard domains are much more difficult to disrupt due to strong hydrogen bonding and/or crystallization. Most of the absorption and decrease in mechanical

  16. Poly(ethylene glycol)-co-methacrylamide-co-acrylic acid based nanogels for delivery of doxorubicin.

    Science.gov (United States)

    Kumar, Parveen; Behl, Gautam; Sikka, Manisha; Chhikara, Aruna; Chopra, Madhu

    2016-10-01

    Polymeric nanogels have been widely explored for their potential application as delivery carriers for cancer therapeutics. The ability of nanogels to encapsulate therapeutics by simple diffusion mechanism and the ease of their fabrication to impart target specificity in addition to their ability to get internalized into target cells make them good candidates for drug delivery. The present study aims to investigate the applicability of poly(ethylene glycol)-co-methacrylamide-co-acrylic acid (PMA)-based nanogels as a viable option for the delivery of doxorubicin (DOX). The nanogels were synthesized by free radical polymerization in an inverse mini-emulsion and characterized by nuclear magnetic resonance spectroscopy ((1)H NMR), Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy (TEM), X-ray diffraction and differential scanning calorimetry. DOX was physically incorporated into the nanogels (PMA-DOX) and the mechanism of its in vitro release was studied. TEM experiment revealed spherical morphology of nanogels and the hydrodynamic diameter of the neat nanogels was in the range of 160 ± 46.95 nm. The size of the nanogels increased from 235.1 ± 28.46 to 403.7 ± 89.89 nm with the increase in drug loading capacity from 4.68 ± 0.03 to 13.71 ± 0.01%. The sustained release of DOX was observed upto 80 h and the release rate decreased with increased loading capacity following anomalous release mechanism as indicated by the value of diffusion exponent (n = 0.64-0.75) obtained from Korsmeyer-Peppas equation. Further, cytotoxicity evaluation of PMA-DOX nanogels on HeLa cells resulted in relatively higher efficacy (IC50~5.88 μg/mL) as compared to free DOX (IC50~7.24 μg/mL) thus demonstrating that the preparation is potentially a promising drug delivery carrier.

  17. Biocompatibility and functional performance of a polyethylene glycol acid-grafted cellulosic membrane for hemodialysis.

    Science.gov (United States)

    Sirolli, V; Di Stante, S; Stuard, S; Di Liberato, L; Amoroso, L; Cappelli, P; Bonomini, M

    2000-06-01

    In order to improve the biochemical reactivity of the cellulose polymer, which is mainly attributed to the presence of surface hydroxyl groups, derivatized cellulosic membranes have been engineered replacing or masking some or all of the hydroxyl groups in the manufacturing process of the membrane. The present study was set up to analyze both biocompatibility and functional performance of two different derivatized cellulosic membranes (cellulose diacetate; polyethylene glycol, PEG, acid-grafted cellulose) as compared to a synthetic membrane (polymethylmethacrylate, PMMA). Cellulose diacetate is prepared by substituting hydroxyl groups with acetyl groups; PEG cellulose is obtained by grafting PEG chains onto the cellulosic polymer with a smaller amount of substitution than cellulose diacetate. While the three dialyzers provided similar urea and creatinine removal, the dialyzer containing cellulose diacetate showed a reduced ability to remove 32-microglobulin compared to that containing PEG cellulose or PMMA. A transient reduction in leukocyte count was observed for both derivatized cellulosic membranes. The neutrophil and monocyte counts throughout the entire dialysis session showed a closer parallelism with the cellular expression of the adhesive receptor CD 15s (sialyl-Lewis x molecule) than with CD11b/CD18 expression. Platelet activation, as indicated by the percentage of cells expressing the activation markers CD62P (P-selectin) and CD63 (gp53), occurred with all membranes at 15 min of dialysis and also with PMMA at 30 min. An increased formation of platelet-neutrophil and platelet-monocyte coaggregates was found at 15 and 30 min during dialysis with cellulose diacetate and PMMA but not with PEG cellulose. Generally in concomitance with the increase in platelet-neutrophil coaggregates, an increased hydrogen peroxide production by neutrophils occurred. Our results indicate that derivatizing cellulose may represent a useful approach to improve the biocompatibility

  18. Dense passivating poly(ethylene glycol) films on indium tin oxide substrates.

    Science.gov (United States)

    Schlapak, Robert; Armitage, David; Saucedo-Zeni, Nadia; Hohage, Michael; Howorka, Stefan

    2007-09-25

    We describe the formation and characterization of surface-passivating poly(ethylene glycol) (PEG) films on indium tin oxide (ITO) glass substrates. PEG chains with a molecular weight of 2000 and 5000 D were covalently attached to the substrates in a systematic approach using different coupling schemes. The coupling strategies included the direct grafting with PEG-silane, PEG-methacrylate, and PEG-bis(amine), as well as the two-step functionalization with aldehyde-bearing silane films and subsequent coupling with PEG-bis(amine). Elemental analysis by X-ray photoelectron spectroscopy (XPS) confirmed the successful surface modification, and XPS and ellipsometry provided values for film thicknesses. XPS and ellipsometry thickness values were almost identical for PEG-silane films but differed by up to 400% for the other PEG layers, suggesting a homogeneous layer for PEG-silane but an inhomogeneous distribution for other PEG coatings on the molecularly rough ITO substrates. Atomic force microscopy (AFM) and water contact angle goniometry confirmed the different degrees of surface homogeneity of the polymer films, with PEG-silane reducing the AFM rms surface roughness by 50% and the water contact angle hysteresis by 75% compared to uncoated ITO. The ability of the PEG layers to passivate the substrate against the nonspecific adsorption of biopolymers was tested using fluorescence-labeled immunoglobulin G and DNA oligonucleotides in combination with fluorescence microscopy. The results indicate a positive relationship between film density and homogeneity on one hand and the ability to passivate against biopolymer adhesion on the other hand. The most homogeneous layers prepared with PEG-silane reduced the nonspecific adsorption of fluorescence-labeled DNA by a factor of 300 compared to uncoated ITO. In addition, the study finds that the ratio of film thicknesses derived by ellipsometry and XPS is a useful parameter to quantify the structural integrity of PEG layers on

  19. Prospective randomized comparison of oral sodium phosphate and polyethylene glycol lavage for colonoscopy preparation

    Institute of Scientific and Technical Information of China (English)

    Kai-Lin Hwang; William Tzu-Liang Chen; Koung-Hong Hsiao; Hong-Chang Chen; Ting-Ming Huang; Chien-Ming Chiu; Ger-Haur Hsu

    2005-01-01

    AIM: To compare the effectiveness, patient acceptability, and physical tolerability of two oral lavage solutions prior to colonoscopy in a Taiwanese population. METHODS: Eighty consecutive patients were randomized to receive either standard 4 L of polyethylene glycol (PEG) or 90 mL of sodium phosphate (NaP) in a split regimen of two 45 mL doses separated by 12 h, prior to colonoscopic evaluation. The primary endpoint was the percent of subjects who had completed the preparation. Secondary endpoints included colonic cleansing evaluated with an overall assessment and segmental evaluation, the tolerance and acceptability assessed by a selfadministered structured questionnaire, and a safety profile such as any unexpected adverse events, electrolyte tests, physical exams, vital signs, and body weights. RESULTS: A significantly higher completion rate was found in the NaP group compared to the PEG group(84.2% vs 27.5%, P<0.001). The amount of fluid suctioned was significantly less in patients taking NaP vs PEG (50.13±54.8 cc vs 121.13±115.4 cc, P<0.001),even after controlling for completion of the oral solution(P = 0.031). The two groups showed a comparable overall assessment of bowel preparation with a rate of "good" or "excellent" in 78.9% of patients in the NaPgroup and 82.5% in PEG group (P = 0.778). Patients taking NaP tended to have significantly better colonic segmental cleansing relative to stool amount observedin the descending (94.7% vs 70%, P = 0.007) andtransverse (94.6% vs 74.4%, P = 0.025) colon. Slightly more patients graded the taste of NaP as "good" or "very good" compared to the PEG patients (32.5% vs 12.5%;P = 0.059). Patients' willingness to take the same preparation in the future was 68.4% in the NaP compared to 75% in the PEG group (P = 0.617). There was a significant increase in serum sodium and a significant decrease in phosphate and chloride levels in NaP group on the day following the colonoscopy without any clinical sequelae. Prolonged (

  20. Encapsulation of pancreatic islets within nano-thin functional polyethylene glycol coatings for enhanced insulin secretion.

    Science.gov (United States)

    Kizilel, Seda; Scavone, Andrew; Liu, Xiang; Nothias, Jean-Manuel; Ostrega, Diane; Witkowski, Piotr; Millis, Michael

    2010-07-01

    Covalent attachment of polymers to cells and tissues could be used to solve a variety of problems associated with cellular therapies. Insulin-dependent diabetes mellitus is a disease resulting from the autoimmune destruction of the beta cells of the islets of Langerhans in the pancreas. Transplantation of islets into diabetic patients is an attractive form of treatment, provided that the islets could be protected from the host's immune system to prevent graft rejection, and smaller numbers of islets transplanted in smaller volumes could be sufficient to reverse diabetes. Therefore, a need exists to develop islet encapsulation strategies that minimize transplant volume. In this study, we demonstrate the formation of nano-thin, poly(ethylene glycol) (PEG)-rich functional conformal coatings on individual islets via layer-by-layer assembly technique. The surface of the islets is modified with biotin-PEG-N-hydroxysuccinimide (NHS), and the islets are further covered by streptavidin (SA) and biotin-PEG-peptide conjugates using the layer-by-layer method. An insulinotropic ligand, glucagon-like peptide-1 (GLP-1), is conjugated to biotin-PEG-NHS. The insulinotropic effect of GLP-1 is investigated through layer-by-layer encapsulation of islets using the biotin-PEG-GLP-1 conjugate. The effect of islet surface modification using the biotin-PEG-GLP-1 conjugate on insulin secretion in response to glucose challenge is compared via static incubation and dynamic perifusion assays. The results show that islets coated with the functional PEG conjugate are capable of secreting more insulin in response to high glucose levels compared to control islets. Finally, the presence of SA is confirmed by indirect fluorescent staining with SA-Cy3, and the presence of PEG-peptide on the surface of the islets after treatment with biotin-PEG-GLP-1 is confirmed by indirect fluorescent staining with biotin-PEG-fluorescein isothiocyanate (FITC) and separately with an anti-GLP-1 antibody. This work

  1. Physical properties and stability mechanisms of poly(ethylene glycol) conjugated liposome encapsulated hemoglobin dispersions.

    Science.gov (United States)

    Arifin, Dian R; Palmer, Andre F

    2005-01-01

    Liposomes encapsulating hemoglobin (LEHs) surface-conjugated with 2000 and 550 Da poly(ethylene glycol) (PEG) were produced via extrusion through 400, 200 and 100 nm pore diameter membranes in two types of phosphate buffer with different ionic strengths. The lipid bilayers were composed of dimyristoyl-phosphatidylcholine (DMPC), cholesterol, dimyristoyl-phosphoethanolamine-PEG (DMPE-PEG), dimyristoyl-phosphatidylglycerol (DMPG), and alpha-tocopherol (in a 43:40:10:5:2 mole ratio). N-acetyl-L-cysteine was coencapsulated in order to suppress hemoglobin (Hb) oxidation. Various physical properties of PEG-LEH dispersions were determined: size distribution, encapsulation efficiency, P50 (partial pressure of O2 where half of the oxygen binding sites are saturated with O2), cooperativity coefficient, and encapsulated methemoglobin (MetHb) level. In order to study the stabilization mechanism of these dispersions, the effective bending constant (KB) and the spontaneous radius of curvature (R0) of PEG-LEHs were extracted by fitting a mathematical model describing the size distribution of a liposome dispersion to the experimentally measured size distributions. We observed that liposome dispersions extruded in phosphate buffer (PB) were more monodisperse than liposomes extruded in phosphate buffered saline (PBS), and higher molecular weight PEG promoted the formation of narrower size distributions. Moreover, extrusion in PB and lipid conjugation with higher molecular weight PEG imparted higher bilayer rigidity (high KB), and stabilized the liposome dispersions by the spontaneous curvature mechanism, whereas the other liposome dispersions were stabilized by thermal undulations (low KB). The P50 and cooperativity coefficient of PEG-LEHs extruded in PBS and PB was comparable to that of human blood, and the encapsulated MetHb levels were less than 5%. The highest encapsulation efficiencies obtained were 27%-36% (82-109 mg Hb/mL) for LEH dispersions extruded in PBS and grafted with

  2. Pectinases partitioning in aqueous two-phase systems: an integration of the systems poly(ethylene glycol/crude dextran and poly(ethylene glycol/ammonium sulphate

    Directory of Open Access Journals (Sweden)

    STANA N. PEJIN

    2004-04-01

    Full Text Available The partitioning of pectinases in the poly(ethylene glucol4000/ammonium sulpohate system was studied and also its application for enzymes extraction from the top phase of the poly(ethylene glucol4000/crude dextran system. Almost complete one-sided partition of endo-pectinase and exo-pectinase to the bottom phase of the polymer/salt system was achieved at a tie-line length of 37.16 %. The concentration factors were 1.73 and 3.25, respectively. The highest total endo- and exo-pectinase yields (72.41 % and 69.46 %, respectively were obtained by integration of the polymer/polymer system at a tie-line of 8.61 % and a high phase volume ratio and the polymer/salt system at a tie-line of 30.23 % and a low phase volume ratio. Integration of the partitioning at a high tie-line length in the polymer/polimer and a low tie-line length in the polymer/salt system resulted in a total concentration factor of 1.5 and a purification of 1.66 fold for exo-pectinase. The addition of phosphate to this integrated system improved the total concentration factor and purification fold of the activity to 1.73 and 2.14, respectively.

  3. Formulation of polylactide-co-glycolic acid nanospheres for encapsulation and sustained release of poly(ethylene imine-poly(ethylene glycol copolymers complexed to oligonucleotides

    Directory of Open Access Journals (Sweden)

    Wheatley Margaret A

    2009-04-01

    Full Text Available Abstract Antisense oligonucleotides (AOs have been shown to induce dystrophin expression in muscles cells of patients with Duchenne Muscular Dystrophy (DMD and in the mdx mouse, the murine model of DMD. However, ineffective delivery of AOs limits their therapeutic potential. Copolymers of cationic poly(ethylene imine (PEI and non-ionic poly(ethylene glycol (PEG form stable nanoparticles when complexed with AOs, but the positive surface charge on the resultant PEG-PEI-AO nanoparticles limits their biodistribution. We adapted a modified double emulsion procedure for encapsulating PEG-PEI-AO polyplexes into degradable polylactide-co-glycolic acid (PLGA nanospheres. Formulation parameters were varied including PLGA molecular weight, ester end-capping, and sonication energy/volume. Our results showed successful encapsulation of PEG-PEI-AO within PLGA nanospheres with average diameters ranging from 215 to 240 nm. Encapsulation efficiency ranged from 60 to 100%, and zeta potential measurements confirmed shielding of the PEG-PEI-AO cationic charge. Kinetic measurements of 17 kDa PLGA showed a rapid burst release of about 20% of the PEG-PEI-AO, followed by sustained release of up to 65% over three weeks. To evaluate functionality, PEG-PEI-AO polyplexes were loaded into PLGA nanospheres using an AO that is known to induce dystrophin expression in dystrophic mdx mice. Intramuscular injections of this compound into mdx mice resulted in over 300 dystrophin-positive muscle fibers distributed throughout the muscle cross-sections, approximately 3.4 times greater than for injections of AO alone. We conclude that PLGA nanospheres are effective compounds for the sustained release of PEG-PEI-AO polyplexes in skeletal muscle and concomitant expression of dystrophin, and may have translational potential in treating DMD.

  4. Ocular permeability of pirenzepine hydrochloride enhanced by methoxy poly(ethylene glycol)-poly(D, L-lactide) block copolymer.

    Science.gov (United States)

    Tu, Jiasheng; Pang, Hui; Yan, Zhen; Li, Pengmei

    2007-10-01

    Methoxy poly(ethylene glycol)-poly(D, L-lactide) block copolymer was tested as an ocular permeation enhancer for pirenzepine hydrochloride. The block copolymers with the methoxy poly(ethylene glycol) to poly(D, L-lactide) weight ratio of 80/20, 50/50, 40/60 were synthesized by a ring-opening polymerization procedure. In vitro transcorneal experiments demonstrated that the block copolymer 80/20 significantly enhanced the transcorneal permeation of pirenzepine at the mass ratio of 1/1.4 (pirenzepine hydrochloride/copolymer). Interaction between pirenzepine and copolymer was identified by infrared spectroscopy analysis and dialysis experiments. Ocular pharmacokinetics of pirenzepine/copolymer preparation by in vivo instillation experiments confirmed that block copolymer could enhance the ocular penetration of pirenzepine. Ocular chronic toxicity experiments of block copolymer and pirenzepine/copolymer preparation were studied on rabbits, and no significant toxicity in both groups was observed within 9 months. It could conclude that pirenzepine/copolymer preparation is effective and safe in ocular delivery of pirenzepine.

  5. Dispersive Surface Energy and Acid-Base Parameters of Tosylate Functionalized Poly(ethylene glycol via Inverse Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Feyza Sesigur

    2014-01-01

    Full Text Available An inverse gas chromatographic (IGC study of the sorption properties of poly(ethylene glycol modified with tosylate (PEG-TOS was presented. PEG-TOS was synthesized via the tosylation of the corresponding poly(ethylene glycol (PEG with p-toluenesulfonyl chloride in the basic medium. The synthesized PEG-Tos was characterized by FTIR-ATR and 1HNMR techniques. The retention diagrams of n-hexane, n-heptane, n-octane, n-nonane, n-decane, dichloromethane, chloroform, acetone, tetrahydrofuran, ethyl acetate, and ethanol on the PEG and PEG-Tos were plotted at temperatures in K between 303 and 373 by inverse gas chromatography technique. The dispersive component of the surface-free energy, γSD, of studied adsorbent surface was estimated using retention times of different nonpolar organics in the infinite dilution region. Thermodynamic parameters of adsorption (free energy, ΔGAS, enthalpy, ΔHAS, and entropy, ΔSAS, dispersive components of the surface energies, γSD, and the acid, KA, and base, KD, constants for the PEG and PEG-Tos were calculated and the results were discussed.

  6. Synthesis of bridged β-cyclodextrin–polyethylene glycol and evaluation of its inhibition performance in oilfield wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Changjun, E-mail: changjunzou@126.com; Liu, Yuan; Yan, Xueling; Qin, Yibie; Wang, Meng; Zhou, Lu

    2014-10-15

    The bridged β-cyclodextrin–polyethylene glycol (β-CD–PEG) is synthesized through reaction of β-CD with PEG, which has been characterized by Fourier transform infrared spectroscope. The inhibition efficiency of bridged β-CD–PEG on corrosion of Q235 carbon steel in 0.5 M HCl solution has been investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. The results show that β-CD–PEG acted as a mixed-type inhibitor and performed excellent inhibiting effect for the corrosion of the Q235 carbon steel. The steel surface morphologies are analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) and then an adsorption mechanism model is proposed. The high inhibitory efficiency of β-CD–PEG is related with the adsorption of polymer molecules at the steel surface and a protective film formation. Finally, these results present a novel corrosion inhibitor works in oil-gas field. - Highlights: • The bridged β-CD–PEG is synthesized by polyethylene glycol and cyclodextrin. • The bridged β-CD–PEG acts as an inhibitor for carbon steel in oilfield wastewater. • The high inhibitory efficiency is related with a protective film formation. • The adsorption of β-CD–PEG is well described by the Langmuir adsorption isotherm.

  7. In situ forming poly(ethylene glycol)-based hydrogels via thiol-maleimide Michael-type addition.

    Science.gov (United States)

    Fu, Yao; Kao, Weiyuan John

    2011-08-01

    The incorporation of cells and sensitive compounds can be better facilitated without the presence of UV or other energy sources that are common in the formation of biomedical hydrogels such as poly(ethylene glycol) hydrogels. The formation of hydrogels by the step-growth polymerization of maleimide- and thiol-terminated poly(ethylene glycol) macromers via Michael-type addition is described. The effects of macromer concentration, pH, temperature, and the presence of biomolecule gelatin on gel formation were investigated. Reaction kinetics between maleimide and thiol functional groups were found to be rapid. Molecular weight increase over time was characterized via gel permeation chromatography during step-growth polymerization. Swelling and degradation results showed incorporating gelatin enhanced swelling and accelerated degradation. Increasing gelatin content resulted in the decreased storage modulus (G'). The in vitro release kinetics of fluorescein isothiocyanate (FITC)-labeled dextran from the resulting matrices demonstrated the potential in the development of novel in situ gel-forming drug delivery systems. Moreover, the resulting networks were minimally adhesive to primary human monocytes, fibroblasts, and keratinocytes thus providing an ideal platform for further biofunctionalizations to direct specific biological response.

  8. The effect of two different polyethylene glycol (PEG) derivatives on the immunological response of PEG grafted pancreatic islets.

    Science.gov (United States)

    Aghajani-Lazarjani, Hamideh; Vasheghani-Farahani, Ebrahim; Shojaosadati, Seyed Abbas; Hashemi-Najafabadi, Sameereh; Zahediasl, Saleh; Tiraihi, Taki; Atyabi, Fatemeh

    2010-12-01

    Islet transplantation is one of the promising ways to treat diabetes. To reduce the immune system response, several methods have been developed, a novel one being the grafting of methoxy polyethylene glycol (mPEG) derivatives onto collagen capsules of islets. In this study, the effects of the first and second generations of activated mPEG on the immunological response of polyethylene glycol (PEG) grafted pancreatic islets were studied. mPEG-Succinimidyl carbonate (mPEG-SC) and mPEG-succinimidyl propionic acid (mPEG-SPA) (with nominal molecular weight 5 kDa), typical of the first and second generations of activated mPEG, were selected, respectively. Both activated mPEGs did not affect the morphology, viability, or functionality of PEGylated islets compared to free islets (naked islets). The amount of IL-2 secreted from lymphocytes co-cultured with mPEG-SPA grafted islets (131.83 ± 15.28 pg/ml) was not significantly different from that with mPEG-SC grafted islets (156.09 ± 27.94 pg/ml). These results indicated that both mPEG-SC and mPEG-SPA had the same effect for camouflaging Langerhans islets, but the former is more suitable due to its easier synthesis process.

  9. Preliminary evaluation of local drug delivery of amphotericin B and in vivo degradation of chitosan and polyethylene glycol blended sponges.

    Science.gov (United States)

    Parker, Ashley Cox; Rhodes, Cheyenne; Jennings, Jessica Amber; Hittle, Lauren; Shirtliff, Mark; Bumgardner, Joel D; Haggard, Warren O

    2016-01-01

    This research investigated the combination of polyethylene glycol with chitosan in point-of-care loaded sponges made by one or two lyophilizations for adjunctive local antifungal delivery in musculoskeletal wounds. Blended and control chitosan sponges were evaluated in vitro for antifungal release and activity, degradation, cytocompatibility, and characterized for spectroscopic, crystallinity, thermal, and morphologic material properties. In vivo biocompatibility and degradation of sponges were also evaluated in a rat intramuscular pouch model 4 and 10 days after implantation. Blended sponges released amphotericin B active against Candida albicans (>0.25 µg/mL) over 72 h and did not elicit cytotoxicity response of fibroblasts. Blended sponges exhibited decreases in surface roughness, decreased thermal decomposition temperatures, as well as small Fourier transform infrared spectroscopy and crystallinity differences, compared with chitosan-only sponges. Three of the four blended sponge formulations exhibited 31%-94% increases in in vitro degradation from the chitosan sponges after 10 days, but did not demonstrate the same increase in in vivo degradation. Low inflammatory in vivo tissue response to blended and chitosan-only sponges was similar over 10 days. These results demonstrated that adding polyethylene glycol to chitosan sponges does improve local antifungal release, cytocompatibility, and in vitro degradation, but does not increase in vivo degradation.

  10. Influence of polyethylene glycol coating on biodistribution and toxicity of nanoscale graphene oxide in mice after intravenous injection

    Directory of Open Access Journals (Sweden)

    Li B

    2014-10-01

    Full Text Available Bo Li,1,2 Xiao-Yong Zhang,1 Jian-Zhong Yang,1 Yu-Jie Zhang,1 Wen-Xin Li,1 Chun-Hai Fan,1 Qing Huang1 1Laboratory of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 2Department of Human Anatomy, College of Basic Medical Sciences, Jilin University, Changchun, People’s Republic of China Abstract: In this study, we assessed the in vivo behavior and toxicology of nanoscale graphene oxide (NGO in mice after intravenous injection. The influence of a polyethylene glycol (PEG coating on the distribution and toxicity of the NGO was also investigated. The results show that NGO is mainly retained in the liver, lung, and spleen. Retention in the lung is partially due to NGO aggregation. The PEG coating reduces the retention of NGO in the liver, lung, and spleen and promotes the clearance of NGO from these organs, but NGO and NGO-PEG are still present after 3 months. The PEG coating effectively reduces the early weight loss caused by NGO and alleviates NGO-induced acute tissue injuries, which can include damage to the liver, lung, and kidney, and chronic hepatic and lung fibrosis. Keywords: graphene oxide, biodistribution, toxicity, polyethylene glycol

  11. Poly(ethylene glycol)-block-poly(glycidyl methacrylate) with oligoamine side chains as efficient gene vectors.

    Science.gov (United States)

    Ma, Ming; Li, Feng; Chen, Fu-jie; Cheng, Si-xue; Zhuo, Ren-xi

    2010-02-11

    Well-defined diblock copolymers, poly(ethylene glycol)-block-poly(glycidyl methacrylate)s (PEG-b-PGMAs), with different poly(glycidyl methacrylate) (PGMA) chains, were prepared via atom transfer radical polymerization (ATRP) from the same macromolecular initiator 2-bromoisobutyryl-terminated poly(ethylene glycol) (PEG). Ethyldiamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), and polyethyleneimine (PEI) with an M(W) of 400 (PEI(400)) were used to decorate PEG-b-PGMAs to get the cationic polymers PEG-b-PGMA- oligoamines. These cationic polymers possessed high buffer capability and could condense plasmid DNA (pDNA) into nanoscaled complexes of 125-530 nm. These complexes showed the positive zeta potential of 20-35 mV at N/P ratios of 10-50. Most of them exhibited very low cytotoxicity and good transfection efficiency in 293T cells. The presence of the serum medium did not decrease the transfection efficiency due to the steric stabilization of the PEG chains.

  12. Enhanced antifouling behaviours of polyvinylidene fluoride membrane modified through blending with nano-TiO{sub 2}/polyethylene glycol mixture

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Wang, Zhiwei, E-mail: zwwang@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Zhang, Xingran [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Zheng, Xiang, E-mail: zhengxiang7825@163.com [School of Environment and Natural Resources, Renmin University of China, Beijing, 100872 (China); Wu, Zhichao [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China)

    2015-08-01

    Graphical abstract: - Highlights: • Nano-TiO{sub 2}/polyethylene glycol (PEG) mixture was used to modify PVDF membranes. • The steric hindrance effects of PEG enabled the dispersion of nanoparticles. • The energy barrier between SMP and modified membranes was increased. • The modification by nano-TiO{sub 2}/PEG well improved the anti-fouling ability. - Abstract: Titanium dioxide (TiO{sub 2}) nanoparticles/polyethylene glycol (PEG) mixture was used to modify polyvinylidene fluoride (PVDF) membranes aiming to improve their antifouling ability. The use of PEG could improve the dispersion of nanoparticles thanks to steric hindrance effects. Test results showed that compared to the original PVDF membrane, the modified membranes had higher hydrophilicity and lower negative Zeta potential, facilitating membrane fouling control. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) analysis indicated that the addition of TiO{sub 2} nanoparticles improved their electron donor monopolarity, i.e., enhanced electron-donating ability. The interaction energy barrier between soluble microbial products (SMP) and membrane surfaces was also improved, indicating that anti-fouling ability of the modified membrane was elevated. The optimal dosage of nano-TiO{sub 2} was found to be 0.15%, and further increase of dosage resulted in the aggregation of nanoparticles which consequently impaired the modification efficiency. Quartz crystal microbalance with dissipation (QCM-D) monitoring and SMP filtration tests confirmed the antifouling ability of the modified membrane.

  13. Phase Behavior and Dynamics of the ABA Triblock Copolymer Poly(Ethylene Glycol) Distearate Doped with Lithium Perchlorate

    Science.gov (United States)

    Giotto, Marcus V.; Sangiorge, Clausymara L.; Harris, Douglas J.; de Oliveira, Armando L.; Schmidt-Rohr, Klaus; Bonagamba, Tito J.

    2002-03-01

    Poly(ethylene glycol) distearate (PEGD) complexed with lithium perchlorate has been studied by NMR, SAXS, DSC, and Polarized-Light Optical Microscopy (PLOM). Unlike other polymer electrolytes, highly Lithium-doped PEGD samples exhibit sharp Li-7 NMR quadrupolar powder patterns even at temperatures well above the melting point, indicating that this copolymer is microphase separated and the dynamics in the poly(ethylene glycol) (PEG) phase are anisotropic. Measurements of the Li-7 central transition linewidth in highly doped samples show three distinct line narrowings, due to the PEG glass transition ( 20°C), the stearate melting point of the polymer ( 35°C), and an order-disorder transition ( 72°C). SAXS, DSC, and PLOM confirm the presence of a microphase-separated state up to 72 °C. C-13 and H-1 NMR show that the segmental mobility in the ordered state is reduced compared to the isotropic melt. The results confirm the previously proposed order-disorder model to explain the dependence of the ionic conductivity on the lithium concentration for Lithium-doped PEGD samples.

  14. Dual-Functional Polyethylene Glycol-b-polyhexanide Surface Coating with in Vitro and in Vivo Antimicrobial and Antifouling Activities.

    Science.gov (United States)

    Zhi, Zelun; Su, Yajuan; Xi, Yuewei; Tian, Liang; Xu, Miao; Wang, Qianqian; Padidan, Sara; Li, Peng; Huang, Wei

    2017-03-29

    In recent years, microbial colonization on the surface of biomedical implants/devices has become a severe threat to human health. Herein, surface-immobilized guanidine derivative block copolymers create an antimicrobial and antifouling dual-functional coating. We report the preparation of an antimicrobial and antifouling block copolymer by the conjugation of polyhexanide (PHMB) with either allyl glycidyl ether or allyloxy polyethylene glycol (APEG; MW 1200 and 2400). The allyl glycidyl ether modified PHMB (A-PHMB) and allyloxy polyethylene glycol1200/2400 modified PHMB (APEG1200/2400-PHMB) copolymers were grafted onto a silicone rubber surface as a bottlebrush-like coating, respectively, using a plasma-UV-assisted surface-initiated polymerization. Both A-PHMB and APEG1200/2400-PHMB coatings exhibited excellent broad-spectrum antimicrobial properties against Gram-negative/positive bacteria and fungi. The APEG2400-PHMB coating displayed an improved antibiofilm as well as antifouling properties and a long reusable cycle, compared with two other coatings, due to its abundant PEG blocks among those copolymers. Also, the APEG2400-PHMB-coated silicone coupons were biocompatible toward mammalian cells, as revealed by in vitro hemocompatibile and cytotoxic assays. An in vivo study showed a significant decline of Escherichia coli colonies with a 5-log reduction, indicating the APEG2400-PHMB coating surface worked effectively in the rodent subcutaneous infection model. This PHMB-based block copolymer coating is believed to be an effective strategy to prevent biomaterial-associated infections.

  15. Poly(ethylene glycol) on the liposome surface: on the mechanism of polymer-coated liposome longevity.

    Science.gov (United States)

    Torchilin, V P; Omelyanenko, V G; Papisov, M I; Bogdanov, A A; Trubetskoy, V S; Herron, J N; Gentry, C A

    1994-10-12

    The hypothetical model is built explaining the molecular mechanism of protective action of poly(ethylene glycol) on liposomes in vivo. The protective layer of the polymer on the liposome surface is considered as a statistical 'cloud' of polymer possible conformations in solution. Computer simulation was used to demonstrate that relatively a small number of liposome-grafted molecules of hydrophilic and flexible polymer can create a dense protective conformational cloud over the liposome surface preventing opsonizing protein molecules from contacting liposome. A more rigid polymer fails to form this dense protective cloud, even when hydrophilic. Computer simulation was also used to reveal possible heterogeneity of reactive sites on a polymer-coated liposome surface, and to estimate the optimal polymer-to-lipid ratio for efficient liposome protection. Experiments have been performed with the quenching of liposome-associated fluorescent label (nitrobenzoxadiazole or fluorescein) with protein (rhodamine-ovalbumin or anti-fluorescein antibody) from solution. It was shown that poly(ethylene glycol) grafting to liposomes hinders protein interaction with the liposome surface, whereas liposome-grafted dextran (more rigid polymer) in similar quantities does not affect protein-liposome interaction. Highly-reactive and low-reactive populations of chemically identical reactive sites have been found on polymer-coated liposomes. Experimental data satisfactory confirm the suggested mechanism for the longevity of polymer-modified liposome.

  16. Poly(ethylene glycol)-poly(lactic-co-glycolic acid) core-shell microspheres with enhanced controllability of drug encapsulation and release rate.

    Science.gov (United States)

    Cha, Chaenyung; Jeong, Jae Hyun; Kong, Hyunjoon

    2015-01-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres have been widely used as drug carriers for minimally invasive, local, and sustained drug delivery. However, their use is often plagued by limited controllability of encapsulation efficiency, initial burst, and release rate of drug molecules, which cause unsatisfactory outcomes and several side effects including inflammation. This study presents a new strategy of tuning the encapsulation efficiency and the release rate of protein drugs from a PLGA microsphere by filling the hollow core of the microsphere with poly(ethylene glycol) (PEG) hydrogels of varying cross-linking density. The PEG gel cores were prepared by inducing in situ cross-linking reactions of PEG monoacrylate solution within the PLGA microspheres. The resulting PEG-PLGA core-shell microspheres exhibited (1) increased encapsulation efficiency, (2) decreased initial burst, and (3) a more sustained release of protein drugs, as the cross-linking density of the PEG gel core was increased. In addition, implantation of PEG-PLGA core-shell microspheres encapsulated with vascular endothelial growth factor (VEGF) onto a chicken chorioallantoic membrane resulted in a significant increase in the number of new blood vessels at an implantation site, while minimizing inflammation. Overall, this strategy of introducing PEG gel into PLGA microspheres will be highly useful in tuning release rates and ultimately in improving the therapeutic efficacy of a wide array of protein drugs.

  17. Degradative properties and cytocompatibility of a mixed-mode hydrogel containing oligo[poly(ethylene glycol)fumarate] and poly(ethylene glycol)dithiol.

    Science.gov (United States)

    Brink, Kelly S; Yang, Peter J; Temenoff, Johnna S

    2009-02-01

    Our laboratory is currently exploring synthetic oligo(poly(ethylene glycol)fumarate) (OPF)-based biomaterials as a means to deliver fibroblasts to promote regeneration of central/partial defects in tendons and ligaments. In order to further modulate the swelling and degradative characteristics of OPF-based hydrogels, OPF crosslinking via a radically initiated, mixed-mode reaction involving poly(ethylene glycol) (PEG)-diacrylate and PEG-dithiol was investigated. Results demonstrate that mixed-mode hydrogels containing OPF can be formed and that the presence of 20 wt.% PEG-dithiol increases swelling and decreases degradation time vs. 10 wt.% PEG-dithiol and non-thiol-containing hydrogels (20% thiol fold swelling 28.7+/-0.8; 10% thiol fold swelling 11.6+/-1.4; non-thiol 8.7+/-0.2; 20% thiol-containing hydrogels degrade within 15 days in vitro). After encapsulation, tendon/ligament fibroblasts remained largely viable over 8 days of static culture. While the presence of PEG-dithiol did not significantly affect cellularity or collagen production within the constructs over this time period, image analysis revealed that the 20% PEG-dithiol gels did appear to promote cell clustering, with greater values for aggregate area observed by day 8. These experiments suggest that mixed-mode OPF-based hydrogels may provide an interesting alternative as a cell carrier for engineering a variety of soft orthopedic tissues, particularly for applications when it is important to encourage cell-cell contact.

  18. Biocompatibility Assessment of Polyethylene Glycol-Poly L-Lysine-Poly Lactic-Co-Glycolic Acid Nanoparticles In Vitro and In Vivo.

    Science.gov (United States)

    Guo, Liting; Chen, Baoan; Liu, Ran; Xia, Guohua; Wang, Yonglu; Li, Xueming; Wei, Chen; Wang, Xuemei; Jiang, Hulin

    2015-05-01

    The present study was designed to evaluate the biocompatibility of nanoparticles polyethylene glycol (PEG)-poly L-lysine (PLL)-poly lactic-co-glycolic acid copolymer (PLGA) (PEG-PLL-PLGA) before clinical application. We applied some tests to assess the safety of PEG-PLL-PLGA nanoparticles (NPs). There was low cytotoxicity of PEG-PLL-PLGA NPs in vitro as detected by MTT assay. Cell apoptosis and intracellular accumulation of PEG-PLL-PLGA were determined by FCM assay. The apoptotic rate induced by nanoparticles and the fluorescence intensity of intracellular daunorubicin (DNR) demonstrated that DNR-PEG-PLL-PLGA could be taken up by the mouse fibroblast cells (L929 cells). Hemolysis test and micronucleus (MN) assay demonstrated that the nanoparticles have no obviously blood toxicity and genotoxicity. DNR-PEG-PLL-PLGA NPs were injected into mice through tail vein to calculate the median lethal dose (LD50), the results showed that they had a wide safe scale. Blood was taken by removing the eyeball of mice to study the influence of DNR-PEG-PLL-PLGA in hepatic and renal functions. The results revealed that there was no significant difference as compared with the control group. Interestingly, the pathologic changes of heart, liver, spleen, lung and kidney were observed in nanoparticles treated mice. Thus, this study demonstrates that PEG-PLL-PLGA NPs appear to be highly biocompatible and safe nanoparticles that can be suitable for further application in the treatment of tumor.

  19. Biodegradable Poly (Lactic-co-Glycolic Acid)-Polyethylene Glycol Nanocapsules: An Efficient Carrier for Improved Solubility, Bioavailability, and Anticancer Property of Lutein.

    Science.gov (United States)

    Arunkumar, Ranganathan; Prashanth, Keelara Veerappa Harish; Manabe, Yuki; Hirata, Takashi; Sugawara, Tatsuya; Dharmesh, Shylaja Mallaiah; Baskaran, Vallikannan

    2015-06-01

    Lutein bioavailability is limited because of its poor aqueous solubility. In this study, lutein-poly (lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG) nanocapsules were prepared to improve the solubility, bioavailability, and anticancer property of lutein. The scanning electron microscopy and dynamic light scattering examination revealed that the nanocapsules are smooth and spherical with size ranging from 80 to 500 nm (mean = 200 nm). In vitro lutein release profile from nanocapsules showed controlled sustainable release (66%) up to 72 h. Aqueous solubility of lutein nanocapsules was much higher by 735-fold than the lutein. Fourier transform infrared spectroscopy analyses showed no chemical interaction among PLGA, PEG, and lutein, indicating possible weak intermolecular forces like hydrogen bonds. X-ray diffraction revealed lutein is distributed in a disordered amorphous state in nanocapsules. Postprandial plasma kinetics (area under the curve) of an oral dose of lutein from nanocapsules was higher by 5.4-fold compared with that of micellar lutein (control). The antiproliferative effect of lutein from nanocapsules (IC50 value, 10.9 μM) was higher (43.6%) than the lutein (IC50 value, 25 μM). Results suggest that PLGA-PEG nanocapsule is an efficient carrier for enhancing hydrophilicity, bioavailability, and anticancer property of lipophilic molecules such as lutein.

  20. Liver-targeting Resibufogenin-loaded poly(lactic-co-glycolic acid)-d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles for liver cancer therapy

    Science.gov (United States)

    Chu, Qiuchen; Xu, Hong; Gao, Meng; Guan, Xin; Liu, Hongyan; Deng, Sa; Huo, Xiaokui; Liu, Kexin; Tian, Yan; Ma, Xiaochi

    2016-01-01

    Liver cancer remains a major problem around the world. Resibufogenin (RBG) is a major bioactive compound that was isolated from Chansu (also called toad venom or toad poison), which is a popular traditional Chinese medicine that is obtained from the skin secretions of giant toads. RBG has strong antitumor effects, but its poor aqueous solubility and its cardiotoxicity have limited its clinical use. The aim of this study was to formulate RBG-loaded poly(lactic-co-glycolic acid) (PLGA)-d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RPTN) to enhance the treatment of liver cancer. RPTN, RBG-loaded PLGA nanoparticle (RPN), and RBG/coumarin-6-loaded PLGA-d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RCPTN) were prepared. The cellular uptake of RCPTN by HepG2 and HCa-F cells was analyzed using confocal laser scanning microscopy. Apoptosis was induced in HepG2 cells by RPTN, RBG solution (RS), and 5-fluorouracil solution (used as the negative controls), as assayed using flow cytometry. LD50 (median lethal dose) values were determined for RS and RPTN, and the liver-targeting properties were determined for RCPTN in intravenously injected mice. A pharmacokinetic study was conducted in rats, and the in vivo therapeutic effects of RPTN, RPN, and RS were examined in a mouse tumor model. The results showed that RCPTN simultaneously delivered both coumarin-6 and RBG into HepG2 and HCa-F cells. The ratio of apoptotic cells was increased in the RPTN group. The LD50 for RPTN was 2.02-fold higher than the value for RS. Compared to RS, RPTN and RPN both showed a significant difference in vivo not only in the pharmacodynamic study but also in anticancer efficacy, and RPTN performed much better than RPN. The detection indexes for drug concentration and fluorescence inversion microscopy images both demonstrated that RCPTN was much better at targeting the liver than RS. The liver-targeting RPTN, which displayed enhanced pharmacological effects and

  1. Liver-targeting Resibufogenin-loaded poly(lactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles for liver cancer therapy

    Directory of Open Access Journals (Sweden)

    Chu QC

    2016-01-01

    Full Text Available Qiuchen Chu,1,* Hong Xu,2,* Meng Gao,1 Xin Guan,1 Hongyan Liu,1 Sa Deng,1 Xiaokui Huo,1 Kexin Liu,1 Yan Tian,1 Xiaochi Ma1 1College of Pharmacy, 2College of Basic Medical Sciences, Dalian Medical University, Dalian, People’s Republic of China *These authors contributed equally to this work Abstract: Liver cancer remains a major problem around the world. Resibufogenin (RBG is a major bioactive compound that was isolated from Chansu (also called toad venom or toad poison, which is a popular traditional Chinese medicine that is obtained from the skin secretions of giant toads. RBG has strong antitumor effects, but its poor aqueous solubility and its cardiotoxicity have limited its clinical use. The aim of this study was to formulate RBG-loaded poly(lactic-co-glycolic acid (PLGA-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RPTN to enhance the treatment of liver cancer. RPTN, RBG-loaded PLGA nanoparticle (RPN, and RBG/coumarin-6-loaded PLGA-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RCPTN were prepared. The cellular uptake of RCPTN by HepG2 and HCa-F cells was analyzed using confocal laser scanning microscopy. Apoptosis was induced in HepG2 cells by RPTN, RBG solution (RS, and 5-fluorouracil solution (used as the negative controls, as assayed using flow cytometry. LD50 (median lethal dose values were determined for RS and RPTN, and the liver-targeting properties were determined for RCPTN in intravenously injected mice. A pharmacokinetic study was conducted in rats, and the in vivo therapeutic effects of RPTN, RPN, and RS were examined in a mouse tumor model. The results showed that RCPTN simultaneously delivered both coumarin-6 and RBG into HepG2 and HCa-F cells. The ratio of apoptotic cells was increased in the RPTN group. The LD50 for RPTN was 2.02-fold higher than the value for RS. Compared to RS, RPTN and RPN both showed a significant difference in vivo not only in the pharmacodynamic study but also in

  2. Tribological characteristics of polyethylene glycol (PEG) as a lubricant for wear resistance of ultra-high-molecular-weight polyethylene (UHMWPE ) in artificial knee join.

    Science.gov (United States)

    Kobayashi, Masanori; Koide, Takayuki; Hyon, Suong-Hyu

    2014-10-01

    For the longevity of total knee joint prostheses, we have developed an artificial lubricant using polyethylene glycol (PEG) for the prevention of wear of ultra-high-molecular-weight polyethylene (UHMWPE). In the present study, the lubricative function of this PEG lubricant was evaluated by a wear test using Co-Cr alloy and UHMWPE counter surface samples. As a result, human synovial fluid including the PEG lubricant showed good result regarding the wear volume and a worn surface of UHMWPE. Considering its lubrication mechanism, it is suspected that interaction between the PEG molecules and the proteins in synovial fluid was involved. Since PE molecules are also organic compounds having a hydroxyl group at one or both ends, the albumin and PEG molecule complex would have bound more strongly to the metal oxide surface and UHMWPE surfaces might enhance and stabilize the lubricating film between the contact surfaces under the boundary lubrication. This study suggests that PEG lubricant as an intra-articular viscous supplement has the potential to prevent wear of UHMWPE by mixing with synovial fluid and to contribute to the longevity of knee joint prostheses.

  3. Fabrication and anti-fouling properties of photochemically and thermally immobilized poly(ethylene oxide) and low molecular weight poly(ethylene glycol) thin films.

    Science.gov (United States)

    Wang, Hui; Ren, Jin; Hlaing, Aye; Yan, Mingdi

    2011-02-01

    Poly(ethylene oxide) (PEO) and low molecular weight poly(ethylene glycol) (PEG) were covalently immobilized on silicon wafers and gold films by way of the CH insertion reaction of perfluorophenyl azides (PFPAs) by either photolysis or thermolysis. The immobilization does not require chemical derivatization of PEO or PEG, and polymers of different molecular weights were successfully attached to the substrate to give uniform films. Microarrays were also generated by printing polymer solutions on PFPA-functionalized wafer or Au slides followed by light activation. For low molecular weight PEG, the immobilization was highly dependent on the quality of the film deposited on the substrate. While the spin-coated and printed PEG showed poor immobilization efficiency, thermal treatment of the PEG melt on PFPA-functionalized surfaces resulted in excellent film quality, giving, for example, a grafting density of 9.2×10(-4)Å(-2) and an average distance between grafted chains of 33Å for PEG 20,000. The anti-fouling property of the films was evaluated by fluorescence microscopy and surface plasmon resonance imaging (SPRi). Low protein adsorption was observed on thermally-immobilized PEG whereas the photoimmobilized PEG showed increased protein adsorption. In addition, protein arrays were created using polystyrene (PS) and PEG based on the differential protein adsorption of the two polymers.

  4. Star poly(ethylene glycol) as a tunable scaffold for neural tissue engineering

    Science.gov (United States)

    Zustiak, Silviya Petrova

    The primary focus of this work was to develop a novel synthetic hydrogel scaffold as an in vitro model to enable future detailed studies of how neurons grow in environments with controllable diffusion profiles of soluble cues and tunable neuronmatrix interactions. The development of in vitro models that enable elucidation of the mechanisms of system performance is a recently emerging goal of tissue engineering. The design of three-dimensional (3D) scaffolds in particular, is motivated by the need to develop model systems that better mimic native tissue as compared to conventional two-dimensional (2D) cell culture substrates. An ideal scaffold is degradable, porous, biocompatible, with mechanical properties to match those of the tissues of interest and with a suitable surface chemistry for cell attachment, proliferation, and differentiation. Although naturally derived materials are more versatile in providing complex biological cues, synthetic polymers are preferable for the design of in vitro models as they provide wider range of properties, controllable degradation rates, and easier processing. Most importantly, their mechanical properties can be decoupled from their biological properties, a crucial issue in interpreting cell responses. The synthetic material provides the structural backbone of the scaffold while biochemical function is added via incorporation of ligands or proteins aimed at triggering specific cell behaviors. As presented in this dissertation, we have developed and characterized a new synthetic 3D hydrogel scaffold from cross-linked poly(ethylene glycol) (PEG). PEG was selected because it is hydrophilic, non-toxic, biocompatible, and inert to protein adhesion. The chosen cross-linking chemistry was a highly specific reaction that occurred under physiological conditions so that cells could be embedded within the gel prior to cross-linking. Controllable degradability was imparted via series of hydrolytically degradable PEG cross-linkers. Thorough

  5. Preparation and Characterizations of RSPP050-Loaded Polymeric Micelles Using Poly(ethylene glycol)-b-Poly(ε-caprolactone) and Poly(ethylene glycol)-b-Poly(D,L-lactide).

    Science.gov (United States)

    Eawsakul, Komgrit; Chinavinijkul, Panarin; Saeeng, Rungnapha; Chairoungdua, Arthit; Tuchinda, Patoomratana; Nasongkla, Norased

    2017-01-01

    RSPP050 (AG50) is one of the semi-synthetic andrographolide that is isolated from Andrographis paniculata NEES (Acanthaceae). The anti-proliferation effects of AG50 against cholangiocarcinoma (HuCCT1) were displayed high cytotoxicity. Unfortunately, poor water solubility of AG50 limited its clinical applications. This study aimed to increase the concentration of AG50 in water and drug loading and release study in phosphate-buffered saline (PBS) in the absence/presence of pig liver esterase enzyme. Cytotoxicity of AG50-loaded polymeric micelles was evaluated against HuCCT1. AG50 loaded micelles were prepared by film sonication and encapsulated by polymers including poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-b-PCL) or poly(ethylene glycol)-b-poly(D,L-lactide) (PEG-b-PLA). Micelle properties were characterized such as solubility, drug loading, drug release and in vitro cytotoxicity against HuCTT1. AG50 was successfully loaded into both types of polymeric micelles. The best drug-polymer (D/P) ratio was 1 : 9. AG50/PCL and AG50/PLA-micelles had small particle size (36.4±5.1, 49.0±2.7 nm, respectively) and high yield (58.2±1.8, 58.8±2.9, respectively). AG50/PLA-micelles (IC50=2.42 µg/mL) showed higher cytotoxicity against HuCCT1 than AG50/PCL-micelles (IC50=4.40 µg/mL) due to the higher amount of AG50 released. Nanoencapsulation of AG50 could provide a promising development in clinical use for cholangiocarcinoma treatment.

  6. Strategies for creating antifouling surfaces using selfassembled poly(ethylene glycol) thiol molecules

    DEFF Research Database (Denmark)

    Lokanathan, Arcot R.

    2011-01-01

    conditions for the reversible, initial attachment of microbial cells. This effect can be obtained by grafting hydrophilic polymeric chains onto surfaces and thereby provide a steric barrier between the substrate surface and the microbial cell. Poly (ethylene glycol) (PEG) is one of the most widely used....... The work focuses on novel strategies to self assemble PEG thiol monolayers with high graft density. One of the strategies investigated involved backfilling a self assembled layer of 2000 Da PEG thiol with shorter oligo (ethylene glycol) (OEG) thiol molecules to form a mixed monolayer. Detailed quantitative...

  7. Pectin-zinc-chitosan-polyethylene glycol colloidal nano-suspension as a food grade carrier for colon targeted delivery of resveratrol

    DEFF Research Database (Denmark)

    Andishmand, Hashem; Mahnaz Tabibiazar; Mohammadifar, Mohammad Amin

    2017-01-01

    The aim of the present study was to develop chitosan-zinc-pectinate-polyethylene glycol (PEG) nanoparticles (NPs) for colon-targeted delivery of resveratrol. The effects of pectin:ZnCl2:chitosan (PZnC) % w/v, pH and ionic strength of media, and addition of PEG on the colloidal stability and release...

  8. In vitro and in vivo comparisons of staphylococcal biofilm formation on a cross-linked poly(ethylene glycol)-based polymer coating.

    NARCIS (Netherlands)

    Saldarriaga Fernandez, I.C.; Mei, H.C. van der; Metzger, S.; Grainger, D.W.; Engelsman, A.F.; Nejadnik, M.R.; Busscher, H.J.

    2010-01-01

    Poly(ethylene glycol) (PEG) coatings are known to reduce microbial adhesion in terms of numbers and binding strength. However, bacterial adhesion remains of the order of 10(4)cm(-2). It is unknown whether this density of bacteria will eventually grow into a biofilm. This study investigates the kinet

  9. Laxation of critically ill patients with lactulose or polyethylene glycol : a two-center randomized, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    van der Spoel, Johan I; Oudemans-van Straaten, Heleen M; Kuiper, Michael A; van Roon, Eric N; Zandstra, Durk F; van der Voort, Peter H J

    2007-01-01

    OBJECTIVE: To study whether lactulose or polyethylene glycol is effective to promote defecation in critically ill patients, whether either of the two is superior, and whether the use of enteral laxatives is related to clinical outcome. DESIGN: Double-blind, placebo-controlled, randomized study.

  10. Application of porcine gastric mucin-conjugated magnetic beads and polyethylene glycol goncentration and detection of human noroviruses from green onion and grape

    Science.gov (United States)

    Objective: To set up detection methods for norovirus in fruits and vegetables by using porcine gastric mucin-conjugated magnetic beads (PGM-MB) and polyethylene glycol 8000 (PEG8000) concentrating and detecting the norovirus in green onion and grape. Methods: The highest virus dilution given a posit...

  11. Methylation of the phosphate oxygen moiety of phospholipid-methoxy(polyethylene glycol) conjugate prevents PEGylated liposome-mediated complement activation and anaphylatoxin production

    DEFF Research Database (Denmark)

    Moghimi, S.M.; Hamad, I.; Andresen, Thomas Lars;

    2006-01-01

    Methoxy(polyethylene glycol), mPEG, -grafted liposomes are known to exhibit prolonged circulation time in the blood, but their infusion into a substantial percentage of human subjects triggers immediate non-IgE-mediated hypersensitivity reactions. These reactions are strongly believed to arise from...

  12. Effects of one-seed juniper and polyethylene glycol on intake, rumen fermentation, and plasma amino acids in sheep and goats fed supplemental protein and tannins.

    Science.gov (United States)

    We tested the effect of polyethylene glycol (PEG) on juniper and total intake, rumen fermentation, and plasma amino acids (AA) of 12 does and 12 ewes fed sudangrass and basal diets containing 10% quebracho tannins with no protein supplement (Control; 5% CP) or high rumen degradable (RDP 15% CP) or u...

  13. Analysis of partitioning of organic compounds and proteins in aqueous polyethylene glycol-sodium sulfate aqueous two-phase systems in terms of solute-solvent interactions.

    Science.gov (United States)

    da Silva, Nuno R; Ferreira, Luisa A; Madeira, Pedro P; Teixeira, José A; Uversky, Vladimir N; Zaslavsky, Boris Y

    2015-10-09

    Partition behavior of nine small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.5M osmolyte (sorbitol, sucrose, trehalose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. It was found out that the partition coefficient of all compounds examined (including proteins) may be described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system differ from those in polyethylene glycol-dextran system.

  14. Laxation of critically ill patients with lactulose or polyethylene glycol : a two-center randomized, double-blind, placebo-controlled trial

    NARCIS (Netherlands)

    van der Spoel, Johan I; Oudemans-van Straaten, Heleen M; Kuiper, Michael A; van Roon, Eric N; Zandstra, Durk F; van der Voort, Peter H J

    2007-01-01

    OBJECTIVE: To study whether lactulose or polyethylene glycol is effective to promote defecation in critically ill patients, whether either of the two is superior, and whether the use of enteral laxatives is related to clinical outcome. DESIGN: Double-blind, placebo-controlled, randomized study. SETT

  15. Conjugation of cell-penetrating peptides with poly(lactic-co-glycolic acid)-polyethylene glycol nanoparticles improves ocular drug delivery

    Science.gov (United States)

    Vasconcelos, Aimee; Vega, Estefania; Pérez, Yolanda; Gómara, María J; García, María Luisa; Haro, Isabel

    2015-01-01

    In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)–polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavailability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG-peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confirmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flurbiprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory efficacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment efficiency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective prevention of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen’s egg test–chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery. PMID:25670897

  16. The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavadi, Ali, E-mail: purjavad@sharif.edu; Tehrani, Zahra Mazaheri; Mahmoudi, Negar [Sharif University of Technology, Polymer Research Laboratory, Department of Chemistry (Iran, Islamic Republic of)

    2015-04-15

    In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating of PEG reduced the wrapping of the protein corona around the nanoparticles. This phenomenon caused increase in Dox release.

  17. Modification of gold surface by grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion.

    Science.gov (United States)

    Zhang, F; Kang, E T; Neoh, K G; Huang, W

    2001-01-01

    Gold surfaces were first treated in an alkanethiol solution to form self-assembled monolayers (SAMs). The thiolated Au surface was then subjected to Ar plasma pretreatment, followed by air exposure and UV-induced graft polymerization of poly(ethylene glycol) methacrylate (PEGMA) macromonomer. In comparison with the 3-mercaptopropionic acid-2-ethylhexyl ester (MPAEE) SAM, the (3-mercaptoproply)trimethoxysilane (MPTMS) SAM on Au exhibited higher stability under the conditions of Ar plasma pretreatment. The graft concentration of the PEGMA polymer on SAM-modified Au surface increased with increasing PEGMA macromonomer concentration and UV-graft polymerization time. The modified-Au surfaces were characterized by X-ray spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle measurement. The Au surface with a high concentration of grafted PEGMA polymer could completely repel protein adsorption and platelet adhesion.

  18. Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles

    Science.gov (United States)

    Shen, Zhiqiang; Loe, David T.; Awino, Joseph K.; Kröger, Martin; Rouge, Jessica L.; Li, Ying

    2016-08-01

    Herein a new multifunctional formulation, referred to as a core-polyethylene glycol-lipid shell (CPLS) nanoparticle, has been proposed and studied in silico via large scale coarse-grained molecular dynamics simulations. A PEGylated core with surface tethered polyethylene glycol (PEG) chains is used as the starting configuration, where the free ends of the PEG chains are covalently bonded with lipid molecules (lipid heads). A complete lipid bilayer is formed at the surface of the PEGylated particle core upon addition of free lipids, driven by the hydrophobic properties of the lipid tails, leading to the formation of a CPLS nanoparticle. The self-assembly process is found to be sensitive to the grafting density and molecular weight of the tethered PEG chains, as well as the amount of free lipids added. At low grafting densities the assembly of CPLS nanoparticles cannot be accomplished. As demonstrated by simulations, a lipid bud/vesicle can be formed on the surface when an excess amount of free lipids is added at high grafting density. Therefore, the CPLS nanoparticles can only be formed under appropriate conditions of both PEG and free lipids. The CPLS nanoparticle has been recognized to be able to store a large quantity of water molecules, particularly with high molecular weight of PEG chains, indicating its capacity for carrying hydrophilic molecules such as therapeutic biomolecules or imaging agents. Under identical size and surface chemistry conditions of a liposome, it has been observed that the CPLS particle can be more efficiently wrapped by the lipid membrane, indicating its potential for a greater efficiency in delivering its hydrophilic cargo. As a proof-of-concept, the experimental realization of CPLS nanoparticles is explicitly demonstrated in this study. To test the capacity of the CPLS to store small molecule cargo a hydrophilic dye was successfully encapsulated in the particles' water soluble layer. The results of this study show the power and

  19. Prediction of liquid-liquid equilibria for polyethylene glycol based aqueous two-phase system by ASOG and UNIFAC method

    Directory of Open Access Journals (Sweden)

    M. Perumalsamy

    2009-03-01

    Full Text Available Liquid-Liquid equilibrium data were obtained for the polyethylene glycol2000(PEG2000-sodium citrate-water system at 298.15, 308.15 and 318.15 K. The effect of temperature on binodal and tie line data was studied and published in a previous article (Murugesan and Perumalsamy, 2005. The interaction parameters of ASOG and UNIFAC models were estimated using the LLE data of PEG2000-sodium citrate-water system and are used to predict the LLE data for PEG6000-sodium citrate-water system at 298.15, 308.15 and 318.15 K (literature data. The predicted LLE data by both ASOG and UNIFAC models showed good agreement with the experimental and literature data.

  20. Influence of Organo-Modified Laponite on the Percolation Behavior of the Systems Based on Polyethylene Glycol and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    E.A. Lysenkov

    2016-11-01

    Full Text Available The electric properties of the systems based on polyethylene glycol (PEG, carbon nanotubes (CNT and laponite is studied using methods of impedance spectroscopy and optical microscopy. It is rotined that at introduction to the system of organo-modified laponite (OLP leads to the shift of the percolation threshold to the area of lower concentrations of CNT. The modeling of impedance spectrums by the method of equivalent circuits is conducted for the systems based on PEG. It is set that the introduction of OLP more than 0,4 % in the system results in the considerable decrease of electrical conductivity. This effect is explained that the platelets of OLP hinder the formation of direct contacts between nanotubes.

  1. Graphene oxide functionalized with silver@silica-polyethylene glycol hybrid nanoparticles for direct electrochemical detection of quercetin.

    Science.gov (United States)

    Veerapandian, Murugan; Seo, Yeong-Tai; Yun, Kyusik; Lee, Min-Ho

    2014-08-15

    A direct electrochemical detection of quercetin based on functionalized graphene oxide modified on gold-printed circuit board chip was demonstrated in this study. Functionalized graphene oxide materials are prepared by the covalent reaction of graphene oxide with silver@silica-polyethylene glycol nanoparticles (~12.35nm). Functionalized graphene oxide electrode shows a well-defined voltammetric response in phosphate buffered saline and catalyzes the oxidation of quercetin to quinone without the need of an enzyme. Significantly, the functionalized graphene oxide modified electrode exhibited a higher sensitivity than pristine gold-printed circuit board and graphene oxide electrodes, a wide concentration range of 7.5 to 1040nM and detection limit of 3.57nM. Developed biosensor platform is selective toward quercetin in the presence of an interferent molecule.

  2. Effect of polyethylene glycol on in vitro gas production kinetics of Prosopis cineraria leaves at different growth stages

    Directory of Open Access Journals (Sweden)

    Mostafa Yousef Elahi

    2014-05-01

    Full Text Available The aim of this experiment was to determine the effect of polyethylene glycol (PEG on in vitro gas production (GP kinetics of Prosopis cineraria leaves at different growth stages. The contents of total phenol (TPH, total tannin (TT and condensed tannin (CT were determined. Effects on in vitro organic matter digestibility (OMD, metabolisable energy (ME and effective dry matter digestibility were assessed by PEG tannin bioassay. No significant differences (P>0.05 were observed for TPH content; however, the stage of flowering had the highest (P0.05 were observed between the growth stage and PEG addition for in vitro GP and its parameters. Addition of PEG increased (P<0.05 GP, OMD and ME in all stages. In conclusion, adding PEG to P. cineraria leaves can improve their nutritive value and could be considered as a potential feed for ruminants.

  3. Preparation of polyethylene glycol macromer grafted membranes by UV irradiation method and their bovine serum albumin permeation characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.; Shim, J.K.; Lee, Y.M. [Hanyang University, Seoul (Korea)

    1999-05-01

    An anti-protein stained ultrafiltration membrane was prepared by grafting monoacrylate polyethylene glycol (PEG) macromer onto apolypropylene (PP) membrane with UV-irradiation methods. PEF-grafted membranes can decrease the fouling resulting from the protein filtration. Monoacrylate PEG is prepared by inducing the acrylate functional groups to the end of PEG chain. Degree of grafting increased with the monomer concentration and UV-irradiation time. The surface modified PP membrane prevented the protein from staining the membrane. The permeation flux of a non-modified PP membrane decreased, while those of other modified PP membranes did not decrease as such. Also, the permeation flux of bovine serum albumin (BSA) solution showed minimum values near the isoelectric point of pH 5.0 and increase apart from pH 5.0. 17 refs., 10 figs., 3 tabs.

  4. Synthesis of an end-group functionalized polyethylene glycol-lipid conjugate for preparation of polymer-grafted liposomes.

    Science.gov (United States)

    Zalipsky, S

    1993-01-01

    Synthesis of a distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG) conjugate, bearing a hydrazide group at the unattached end of the polymer chain, was achieved using a new heterobifunctional polymeric reagent. The heterobifunctional PEG derivative carrying on one end a reactive succinimidyl carbonate (SC) group and at the other terminal a tert-butyloxycarbonyl (Boc) protected hydrazide group was prepared by an efficient four step process from readily available PEG-2000. The SC-end group of the polymer reacted readily with the amino group of DSPE forming a stable urethane attachment between lipid and PEG. Acidolytic removal of the Boc group yielded a hydrazide-PEG-lipid conjugate suitable for preparation of polymer-grafted liposomes. Taking advantage of the well-documented chemical versatility of hydrazide groups, various biologically relevant ligands can be linked to this type of functionalized liposomes.

  5. Dewetting of polystyrene thin films on poly(ethylene glycol)-modified surfaces as a simple approach for patterning proteins.

    Science.gov (United States)

    Cai, Yangjun; Newby, Bi-min Zhang

    2008-05-20

    A simple technique for patterning proteins utilizing dewetted polystyrene (PS) droplets is demonstrated. A polystyrene thin film was spin coated on a poly(ethylene glycol) (PEG) silane-modified surface. As the PS film dewets from the surface, upon annealing, to form droplets, the PEG-silane-modified surface is exposed, which retains its capability to resist protein adsorption, and the PS droplets allow the selective adsorption of proteins. In contrast to the undewetted flat PS film, the droplet surface had a greater amount of adsorbed proteins. Atomic force microscopy scans reveal that the roughness of the droplet surface is higher, and a multilayer of proteins results on the droplet surface. Moreover, micro- and nanoscale droplet patterns can easily be achieved by tuning the thickness of PS thin films. Because dewetting approaches for generating ordered dewetting droplets have been successfully generated by others, those approaches could be easily combined with this technique to fabricate ordered protein patterns.

  6. Influence of polyethylene glycol coating on biodistribution and toxicity of nanoscale graphene oxide in mice after intravenous injection.

    Science.gov (United States)

    Li, Bo; Zhang, Xiao-Yong; Yang, Jian-Zhong; Zhang, Yu-Jie; Li, Wen-Xin; Fan, Chun-Hai; Huang, Qing

    2014-01-01

    In this study, we assessed the in vivo behavior and toxicology of nanoscale graphene oxide (NGO) in mice after intravenous injection. The influence of a polyethylene glycol (PEG) coating on the distribution and toxicity of the NGO was also investigated. The results show that NGO is mainly retained in the liver, lung, and spleen. Retention in the lung is partially due to NGO aggregation. The PEG coating reduces the retention of NGO in the liver, lung, and spleen and promotes the clearance of NGO from these organs, but NGO and NGO-PEG are still present after 3 months. The PEG coating effectively reduces the early weight loss caused by NGO and alleviates NGO-induced acute tissue injuries, which can include damage to the liver, lung, and kidney, and chronic hepatic and lung fibrosis.

  7. The influence of pH, polyethylene glycol and polyacrylic acid on the stability of stem bromelain

    Directory of Open Access Journals (Sweden)

    Letícia Celia de Lencastre Novaes

    2014-04-01

    Full Text Available Enzyme stability is critical in biotechnology, pharmaceutical and cosmetic industries. Investigations on this subject have drawn attention because of its practical application. Bromelain is a thiol-endopeptidase, obtained from pineapple (Ananas comosus, known for its clinical and therapeutic applications, particularly to selective burn debridement and improvement of antibiotic action and anti-inflammatory activities. To date, the use of bromelain in pharmacological or industrial applications is limited, due to commercial availability, costs, and sensitivity to pH and temperature. Therefore, a better understanding of enzyme stability would be of great interest. The aim of this study was to evaluate bromelain activity and stability in several pH (2.0 to 8.0 and in polyethylene glycol and polyacrylic acid solutions. We observed that bromelain was able to maintain its stability at pH 5.0 for the temperatures studied. PEG solutions increased bromelain stability, but PAA solutions had the opposite effect.

  8. Multifunctional copolymer coating of polyethylene glycol, glycidyl methacrylate, and REDV to enhance the selectivity of endothelial cells.

    Science.gov (United States)

    Wei, Yu; Zhang, Jingxun; Li, Haolie; Zhang, Li; Bi, Hong

    2015-01-01

    Multifunctional polymer coatings have potential applications in biomaterials. These coatings possess reactive functional groups for the immobilization of specific biological factors that can influence cellular behavior. These coatings also display low nonspecific protein adsorption. In this study, we prepared a multifunctional polymer coating through the deposition of random copolymers of poly(ethylene glycol) methacrylate (PEGMA) and glycidyl methacrylate (GMA) to prevent nonspecific attachment and enable the covalence of Arg-Glu-Asp-Val (REDV) peptide with endothelial cells (ECs) selectivity. Coatings were characterized by X-ray photoelectron spectroscopy (XPS). The adhesion and proliferation of ECs and smooth muscle cells (SMCs) onto the REDV-modified surface were investigated to understand the synergistic action of antifouling PEG and EC selective REDV peptide conjugated GMA. The copolymers containing GMA and PEG groups are very useful as a multifunctional coating material with anti-fouling and ECs specific adhesion for implant materials surface modification.

  9. The effect of spin-coated polyethylene glycol on the electrical and optical properties of graphene film

    Energy Technology Data Exchange (ETDEWEB)

    Ali Umar, Marjoni Imamora, E-mail: marjoniimamora@gmail.com [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi Selangor (Malaysia); Department of Physics Education, Faculty of Tarbiyah, Sekolah Tinggi Agama Islam Negeri (STAIN) 27213 Batusangkar, West Sumatera (Indonesia); Yap, Chi Chin, E-mail: ccyap@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi Selangor (Malaysia); Awang, Rozidawati, E-mail: rozida@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi Selangor (Malaysia); Mat Salleh, Muhamad, E-mail: mms@ukm.edu.my [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM, Bangi Selangor (Malaysia); Yahaya, Muhammad, E-mail: myahya@ukm.edu.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi Selangor (Malaysia)

    2014-09-15

    Highlights: • The PEG was spin coated on the graphene oxide film prior to thermal reduction. • The sheet resistance of graphene film decreased by PEG modification. • The role of PEG modification was revealed. - Abstract: This paper reports the modification of electrical and optical properties of graphene film by spin coating polyethylene glycol (PEG) solution onto the graphene oxide film followed by thermal reduction process. The PEG solution was deposited onto the graphene oxide film at different spin coating speeds (1000, 1500, 2000, 2500 and 3000 rpm). The introduction of PEG at appropriate spin coating speed results in lower sheet resistance and optical transmittance, probably due to better alignment and stacking of the graphene sheets. It is interesting to find that the dye sensitized solar cell with PEG-modified graphene film as counter electrode showed 4 times increase in power conversion efficiency as compared to that with unmodified graphene film.

  10. A Novel Synthesis Method of Porous Calcium Silicate Hydrate Based on the Calcium Oxide/Polyethylene Glycol Composites

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2013-01-01

    Full Text Available This paper proposed a novel method to prepare porous calcium silicate hydrate (CSH based on the calcium oxide/polyethylene glycol (CaO/PEG2000 composites as the calcium materials. The porosity formation mechanism was revealed via X-ray diffraction (XRD, field-emission scanning electron microscopy (FESEM, Brunauer-Emmett-Teller (BET, and Fourier transformed infrared spectroscopy (FT-IR. The reactivity of silica materials (SiO2 enhanced by increasing pH value. Ca2+ could not sustain release from CaO/PEG2000 and reacted with caused by silica to form CSH until the hydrothermal temperature reached to 170°C, avoiding the hardly dissolved intermediates formation efficiently. The as-prepared CSH, due to the large specific surface areas, exhibited excellent release capability of Ca2+ and OH−. This porous CSH has potential application in reducing the negative environmental effects of continual natural phosphate resource depletion.

  11. Semi-interpenetrating polymer networks composed of silk fibroin and poly(ethylene glycol) for wound dressing.

    Science.gov (United States)

    Kweon, Haeyong; Yeo, Joo-hong; Lee, Kwang-gill; Lee, Hyun Chul; Na, Hee Sam; Won, Young Ho; Cho, Chong Su

    2008-09-01

    Semi-interpenetrating polymer networks (SIPNs) composed of silk fibroin (SF) and poly(ethylene glycol) (PEG) were prepared by photopolymerization of a PEG macromer in the presence of SF to improve the mechanical properties of SF sponge as wound dressing. The morphological structure of the SF/PEG SIPNs was observed to be composed of an interconnected microporous surface and a cross-sectional area. SF/PEG SIPNs showed non-cytotoxicity evaluated by a cell proliferation method using L929 fibroblasts. Wound contraction treated with SF/PEG SIPNs sponges was faster than that of Vaseline gauze as a control. Histological observation confirmed that the deposition of collagen in the dermis was organized by covering the wound area with SF/PEG SIPNs. The above results indicated that SF/PEG SIPNs could be used as wound dressing.

  12. Long-Term Controlled Protein Release from Poly(Ethylene Glycol) Hydrogels by Modulating Mesh Size and Degradation.

    Science.gov (United States)

    Tong, Xinming; Lee, Soah; Bararpour, Layla; Yang, Fan

    2015-12-01

    Poly(ethylene glycol) (PEG)-based hydrogels are popular biomaterials for protein delivery to guide desirable cellular fates and tissue repair. However, long-term protein release from PEG-based hydrogels remains challenging. Here, we report a PEG-based hydrogel platform for long term protein release, which allows efficient loading of proteins via physical entrapment. Tuning hydrogel degradation led to increase in hydrogel mesh size and gradual release of protein over 60 days of with retained bioactivity. Importantly, this platform does not require the chemical modification of loaded proteins, and may serve as a versatile tool for long-term delivery of a wide range of proteins for drug-delivery and tissue-engineering applications.

  13. Designed biodegradable hydrogel structures prepared by stereolithography using poly(ethylene glycol)/poly(D,L-lactide)-based resins.

    Science.gov (United States)

    Seck, Tetsu M; Melchels, Ferry P W; Feijen, Jan; Grijpma, Dirk W

    2010-11-20

    Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibitor in DMSO/water was used to build the structures. Porous and non-porous hydrogels with well-defined architectures and good mechanical properties were prepared. Porous hydrogel structures with a gyroid pore network architecture showed narrow pore size distributions, excellent pore interconnectivity and good mechanical properties. The structures showed good cell seeding characteristics, and human mesenchymal stem cells adhered and proliferated well on these materials.

  14. Dynamic interfacial properties of poly(ethylene glycol)-modified ferritin at the solid/liquid interface.

    Science.gov (United States)

    Kumashiro, Yoshikazu; Ikezoe, Yasuhiro; Tamada, Kaoru; Hara, Masahiko

    2008-07-17

    Poly(ethylene glycol)-modified ferritins (PEG-ferritins) with various molecular weights were synthesized by the grafting method, and their dynamic interfacial properties at the solid/liquid interface were investigated. The number of PEG grafted to ferritins was controlled by the amount of 1,1'-carbonyldiimidazole-modified PEG adding to the reaction solution. The adsorption kinetics and energy dissipation of PEG-ferritins onto bare Si substrate and amino-modified Si substrate were investigated with a quartz crystal microbalance (QCM) in 10 mM bis-Tris/HCl buffer (pH 5.8), while their morphologies were characterized by scanning electron microscopy (SEM). The adsorption dynamics of PEG-ferritins onto amino-modified Si substrate were quite different from those of unmodified ferritin, which can be reasonably interpreted by the desorption capability of PEG-ferritins on the surface attributed to amphiphilicity and the high-chain mobility of PEG chains.

  15. Phase Diagrams of the Aqueous Two-Phase Systems of Poly(ethylene glycol/Sodium Polyacrylate/Salts

    Directory of Open Access Journals (Sweden)

    Adalberto Pessoa Junior

    2011-03-01

    Full Text Available Aqueous two-phase systems consisting of polyethylene glycol (PEG, sodium polyacrylate (NaPAA, and a salt have been studied. The effects of the polymer size, salt type (NaCl, Na2SO4, sodium adipate and sodium azelate and salt concentrations on the position of the binodal curve were investigated. The investigated PEG molecules had a molar mass of 2,000 to 8,000 g/mol, while that of NaPAA was 8,000 g/mol. Experimental phase diagrams, and tie lines and calculated phase diagrams, based on Flory-Huggins theory of polymer solutions are presented. Due to strong enthalpic and entropic balancing forces, the hydrophobicity of the added salt has a strong influence on the position of the binodal, which could be reproduced by model calculations.

  16. Synthesis of polyacrylate/polyethylene glycol interpenetrating network hydrogel and its sorption of heavy-metal ions

    Directory of Open Access Journals (Sweden)

    Qunwei Tang, Xiaoming Sun, Qinghua Li, Jihuai Wu and Jianming Lin

    2009-01-01

    Full Text Available A simple two-step aqueous polymerization method was introduced to synthesize a polyacrylate/polyethylene glycol (PAC/PEG interpenetrating network (IPN hydrogel. On the basis of the effects of the ratio of PAC to PEG, neutralization degree, heavy-metal ion concentration, and temperature on the adsorption behavior of PAC/PEG IPN hydrogel toward Ni2 +, Cr3 + and Cd2 +, the preparation conditions were optimized. In our system, the greatest amount of Ni2 +, Cr3 + and Cd2 + adsorbed were 102.34, 49.38 and 33.41 mg g- 1, respectively. The adsorption abilities of a dried PAC/PEG composite and a swollen PAC/PEG IPN hydrogel were compared. It was found that the efficiency of removing metal ions using the swollen hydrogel was greater than that using the dried composite. The adsorption mechanism and model are also discussed.

  17. Synthesis of polyacrylate/polyethylene glycol interpenetrating network hydrogel and its sorption of heavy-metal ions.

    Science.gov (United States)

    Tang, Qunwei; Sun, Xiaoming; Li, Qinghua; Wu, Jihuai; Lin, Jianming

    2009-02-01

    A simple two-step aqueous polymerization method was introduced to synthesize a polyacrylate/polyethylene glycol (PAC/PEG) interpenetrating network (IPN) hydrogel. On the basis of the effects of the ratio of PAC to PEG, neutralization degree, heavy-metal ion concentration, and temperature on the adsorption behavior of PAC/PEG IPN hydrogel toward Ni(2 +), Cr(3 +) and Cd(2 +), the preparation conditions were optimized. In our system, the greatest amount of Ni(2 +), Cr(3 +) and Cd(2 +) adsorbed were 102.34, 49.38 and 33.41 mg g(- 1), respectively. The adsorption abilities of a dried PAC/PEG composite and a swollen PAC/PEG IPN hydrogel were compared. It was found that the efficiency of removing metal ions using the swollen hydrogel was greater than that using the dried composite. The adsorption mechanism and model are also discussed.

  18. Semi-interpenetrating polymer networks composed of silk fibroin and poly(ethylene glycol) for wound dressing

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, HaeYong; Yeo, Joo-hong; Lee, Kwang-gill [Applied Sericulture and Apiculture Division, National Institute of Agricultural Science and Technology, Suwon 441100 (Korea, Republic of); Lee, Hyun Chul; Na, Hee Sam [Department of Microbiology and Research Institute of Medical Sciences, Chonnam National University Medical School, Kwangju (Korea, Republic of); Won, Young Ho [Department of Dermatology, Chonnam National University Medical School, Kwangju (Korea, Republic of); Cho, Chong Su [School of Agricultural Biotechnology, Seoul National University, Seoul 151742 (Korea, Republic of)], E-mail: chocs@plaza.snu.ac.kr

    2008-09-01

    Semi-interpenetrating polymer networks (SIPNs) composed of silk fibroin (SF) and poly(ethylene glycol) (PEG) were prepared by photopolymerization of a PEG macromer in the presence of SF to improve the mechanical properties of SF sponge as wound dressing. The morphological structure of the SF/PEG SIPNs was observed to be composed of an interconnected microporous surface and a cross-sectional area. SF/PEG SIPNs showed non-cytotoxicity evaluated by a cell proliferation method using L929 fibroblasts. Wound contraction treated with SF/PEG SIPNs sponges was faster than that of Vaseline gauze as a control. Histological observation confirmed that the deposition of collagen in the dermis was organized by covering the wound area with SF/PEG SIPNs. The above results indicated that SF/PEG SIPNs could be used as wound dressing.

  19. Poly(ethylene glycol)-graft-poly(vinyl acetate) single-chain nanoparticles for the encapsulation of small molecules.

    Science.gov (United States)

    Bartolini, Arianna; Tempesti, Paolo; Resta, Claudio; Berti, Debora; Smets, Johan; Aouad, Yousef G; Baglioni, Piero

    2017-02-08

    Amphiphilic poly(ethylene glycol)-graft-poly(vinyl acetate) copolymers with a low degree of grafting undergo self-folding in water driven by hydrophobic interactions, resulting in single-chain nanoparticles (SCNPs) possessing a hydrodynamic radius of about 10 nm. A temperature scan revealed a lower critical solution temperature (LCST)-type phase behavior. In addition, SAXS data collected close to the LCST showed that these SCNPs aggregate into one-dimensional elongated objects, preferentially. With respect to the typical linear complex-structured polymer chains, this material is ideally suited for industrial and/or biomedical applications because of its simple molecular architecture and persistence of SCNPs up to 100 mg mL(-1). The so-obtained single-chain globular particles are able to swell upon loading with small hydrophobic molecules therefore promoting solubilization of flavors or drugs, which could be of interest in the food and pharmaceutical industry.

  20. In situ extraction of polar product of whole cell microbial transformation with polyethylene glycol-induced cloud point system.

    Science.gov (United States)

    Wang, Zhilong; Xu, Jian-He; Zhang, Wenzhi; Zhuang, Baohua; Qi, Hanshi

    2008-01-01

    A novel polyethylene glycol-induced cloud point system (PEG-CPS) was developed for in situ extraction of moderate polar product by setting a microbial transformation of benzaldehyde into L-phenylacetylcarbinol (L-PAC) with Saccharomyces cerevisiae (baker's yeast) as a model reaction. The biocompatibility of the microorganism in PEG-CPS was comparatively studied with a series of water-organic solvent two-phase partitioning systems. The tolerance of microorganism to the toxic substrate benzaldehyde was increased and the moderate polar product L-PAC was extracted into the surfactant-rich phase in the PEG-CPS. The novel PEG-CPS fills the gap of in situ extraction of polar product in microbial transformation left by water-organic solvent two-phase partitioning system. At the same time, the application of PEG-CPS in a microbial transformation also avoids expensive solvent when compared with that of aqueous two-phase system or CPS.

  1. Photodynamic therapy of tumors with pyropheophorbide-a-loaded polyethylene glycol–poly(lactic-co-glycolic acid) nanoparticles

    Science.gov (United States)

    Liu, Hui; Zhao, Mei; Wang, Jin; Pang, Mingpei; Wu, Zhenzhou; Zhao, Liqing; Yin, Zhinan; Hong, Zhangyong

    2016-01-01

    Photodynamic therapy (PDT) has many advantages in treating cancers, but the lack of ideal photosensitizers continues to be a major limitation restricting the clinical utility of PDT. This study aimed to overcome this obstacle by generating pyropheophorbide-a-loaded polyethylene glycol–poly(lactic-co-glycolic acid) nanoparticles (NPs) for efficient tumor-targeted PDT. The fabricated NPs were efficiently internalized in the mitochondrion by cancer cells, and they efficiently killed cancer cells in a dose-dependent manner when activated with light. Systemically delivered NPs were highly enriched in tumor sites, and completely ablated the tumors in a xenograft KB tumor mouse model when illuminated with 680 nm light (156 mW/cm2, 10 minutes). The results suggested that this tumor-specific NP-delivery system for pyropheophorbide-a has the potential to be used in tumor-targeted PDT. PMID:27729788

  2. Polyethylene glycol-coupled IGF1 delays motor function defects in a mouse model of spinal muscular atrophy with respiratory distress type 1.

    Science.gov (United States)

    Krieger, Frank; Elflein, Nicole; Saenger, Stefanie; Wirthgen, Elisa; Rak, Kristen; Frantz, Stefan; Hoeflich, Andreas; Toyka, Klaus V; Metzger, Friedrich; Jablonka, Sibylle

    2014-05-01

    Spinal muscular atrophy with respiratory distress type 1 is a neuromuscular disorder characterized by progressive weakness and atrophy of the diaphragm and skeletal muscles, leading to death in childhood. No effective treatment is available. The neuromuscular degeneration (Nmd(2J)) mouse shares a crucial mutation in the immunoglobulin mu-binding protein 2 gene (Ighmbp2) with spinal muscular atrophy with respiratory distress type 1 patients and also displays some basic features of the human disease. This model serves as a promising tool in understanding the complex mechanisms of the disease and in exploring novel treatment modalities such as insulin-like growth factor 1 (IGF1) which supports myogenic and neurogenic survival and stimulates differentiation during development. Here we investigated the treatment effects with polyethylene glycol-coupled IGF1 and its mechanisms of action in neurons and muscles. Polyethylene glycol-coupled IGF1 was applied subcutaneously every second day from post-natal Day 14 to post-natal Day 42 and the outcome was assessed by morphology, electromyography, and molecular studies. We found reduced IGF1 serum levels in Nmd(2J) mice 2 weeks after birth, which was normalized by polyethylene glycol-coupled IGF1 treatment. Nmd(2J) mice showed marked neurogenic muscle fibre atrophy in the gastrocnemius muscle and polyethylene glycol-coupled IGF1 treatment resulted in muscle fibre hypertrophy and slowed fibre degeneration along with significantly higher numbers of functionally active axonal sprouts. In the diaphragm with predominant myogenic changes a profound protection from muscle fibre degeneration was observed under treatment. No effects of polyethylene glycol-coupled IGF1 were monitored at the level of motor neuron survival. The beneficial effects of polyethylene glycol-coupled IGF1 corresponded to a marked activation of the IGF1 receptor, resulting in enhanced phosphorylation of Akt (protein kinase B) and the ribosomal protein S6 kinase in

  3. BULK SYNTHESIS OF SILVER NANORODS IN POLY(ETHYLENE GLYCOL) USING MICROWAVE IRRADIATION

    Science.gov (United States)

    Microwave-assisted (MW), surfactantless, greener approach to bulk synthesis of silver nanorods employing poly (ethylene glycol) (PEG) is described. An aqueous solution of silver nitrate (AgNO-3,- 0.1 M, 4 mL) and 4 mL of PEG (molecular weight 300) were mixed at room temperature t...

  4. Biomass Yield and Steviol Glycoside Production in Callus and Suspension Culture of Stevia rebaudiana Treated with Proline and Polyethylene Glycol.

    Science.gov (United States)

    Gupta, Pratibha; Sharma, Satyawati; Saxena, Sanjay

    2015-06-01

    Enhanced production of steviol glycosides (SGs) was observed in callus and suspension culture of Stevia rebaudiana treated with proline and polyethylene glycol (PEG). To study their effect, yellow-green and compact calli obtained from in vitro raised Stevia leaves were sub-cultured on MS medium supplemented with 2.0 mg l(-1) NAA and different concentrations of proline (2.5-10 mM) and PEG (2.5-10 %) for 2 weeks, and incubated at 24 ± 1 °C and 22.4 μmol m(-2) s(-1) light intensity provided by white fluorescent tubes for 16 h. Callus and suspension culture biomass (i.e. both fresh and dry weight content) was increased with 5 mM proline and 5 % PEG, while at further higher concentrations, they got reduced. Further, quantification of SGs content in callus (collected at 15th day) and suspension culture (collected at 10th and 15th day) treated with and without elicitors was analysed by HPLC. It was observed that chemical stress enhanced the production of SGs significantly. In callus, the content of SGs increased from 0.27 (control) to 1.09 and 1.83 % with 7.5 mM proline and 5 % PEG, respectively, which was about 4.0 and 7.0 times higher than control. However, in the case of suspension culture, the same concentrations of proline and polyethylene glycol enhanced the SG content from 1.36 (control) to 5.03 and 6.38 %, respectively, on 10th day which were 3.7 times and 4.7 times higher than control.

  5. 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.

  6. Mechanical and swelling characterization of poly(N-isopropyl acrylamide -co- methoxy poly(ethylene glycol) methacrylate) sol-gels.

    Science.gov (United States)

    Pollock, Jacob F; Healy, Kevin E

    2010-04-01

    The dimensional stability and rheological properties of a series of comb-like copolymers of N-isopropyl acrylamide (NIPAAm) and methoxy poly(ethylene glycol) methacrylate (mPEGMA), poly(NIPAAm-co-mPEGMA), with varying poly(ethylene glycol) (PEG) graft densities and molecular weights were studied. The thermoresponsive character of the copolymer solutions was investigated by kinetic and equilibrium swelling, as well as by static and dynamic mechanical analysis. Surface response mapping was employed to target particular compositions and concentrations with excellent dimensional stability and a relatively large change in dynamic mechanical properties upon thermoreversible gelation. The mechanical characteristics of the gels depended strongly upon concentration of total polymer and less so upon copolymer ratio. Increased PEG graft density was shown to slow the deswelling rate and increase the equilibrium water content of the gels. Upon gelation at sol concentrations of 1-20 wt.% the materials underwent no deswelling or syneresis and maintained stable gels with a large elastic regime and high yield strain (i.e. elastic and soft but tough), even within the Pascal range of complex shear moduli. These materials are unique in that they maintained a physiologically useful lower critical solution temperature (approximately 33 degrees C), despite having a high PEG content. Copolymers with a high PEG content and low polymer fraction were conveniently transparent in the gel phase, allowing visualization of cellular activity without disrupting the microenvironment. Mesenchymal stem cells showed good viability and proliferation in three-dimensional culture within the gels, despite the lack of ligand incorporation to promote cellular interaction. Multi-component matrices can be created through simple mixing of copolymer solutions and peptide-conjugated linear polymers and proteins to produce combinatorial microenvironments with the potential for use in cell biology, tissue

  7. Self-assembled core-polyethylene glycol-lipid shell nanoparticles demonstrate high stability in shear flow.

    Science.gov (United States)

    Shen, Zhiqiang; Ye, Huilin; Kröger, Martin; Li, Ying

    2017-05-24

    A core-polyethylene glycol-lipid shell (CPLS) nanoparticle consists of an inorganic core coated with polyethylene glycol (PEG) polymers, surrounded by a lipid bilayer shell. It can be self-assembled from a PEGylated core with surface-tethered PEG chains, where all the distal ends are covalently bonded to lipid molecules. Upon adding free lipids, a complete lipid bilayer shell can be formed on the surface driven by the hydrophobic nature of lipid tails, leading to the formation of a CPLS nanoparticle. The stability of CPLS nanoparticles in shear flow has been systematically studied through large scale dissipative particle dynamics simulations. CPLS nanoparticles demonstrate higher stability and less deformation in shear flow, compared with lipid vesicles. Burst leakage of drug molecules inside lipid vesicles and CPLS NPs can be induced by the large pores at their tips. These pores are initiated by the maximum stress in the waist region. It further grows along with the tank-treading motion of vesicles or CPLS NPs in shear flow. However, due to the constraints applied by PEG polymers, CPLS NPs are less deformed than vesicles with comparable size under the same flow conditions. Thus, the less deformed CPLS NPs express a smaller maximum stress at waists, demonstrating higher stability. Pore formation at waists, evolving into large pores on vesicles, leads to the burst leakage of drug molecules and complete rupture of vesicles. In contrast, although similar drug leakage in CPLS nanoparticles can occur at high shear rates, pores initiated at moderate shear rates tend to be short-lived and close due to the constraints mediated by PEG polymers. This kind of 'self-healing' capability can be observed over a wide range of shear rates for CPLS nanoparticles. Our results suggest self-assembled CPLS nanoparticles to exhibit high stability during blood circulation without rapid drug leakage. These features make CPLS nanoparticles candidates for a promising drug delivery platform.

  8. Calibration and validation of the {sup 14}C-labelled polyethylene glycol-binding assay for tannins in tropical browse

    Energy Technology Data Exchange (ETDEWEB)

    Mlambo, V. [Animal Production Unit, FAO/IAEA Agriculture and Biotechnology Laboratory, Seibersdorf (Austria)]. E-mail: vmlambo@agric.uniswa.sz; Makkar, H.P.S. [Animal Production and Health Section, Joint FAO/IAEA Division of Nuclear Techniques in Agriculture and Food, International Atomic Energy Agency, Vienna (Austria)

    2005-08-19

    This study evaluates the radiolabelled polyethylene glycol (PEG)-binding procedure [Silanikove, N., Shinder, D., Gilboa, N., Eyal, M., Nitsan, Z., 1996. Polyethylene glycol-binding to plant samples as an assay for the biological effects of tannins: predicting the negative effects of tannins in Mediterranean browse on rumen degradation. J. Agric. Food Chem. 44, 3230-3234] for tannin analysis, using 27 tropical browse plants. In this method, the amount of PEG bound to a plant sample is assumed to be a reflection of its tannin content. The method was modified to exclude the use of non-tanniniferous substrate for estimating non-specific binding (NSB) in tannin-containing substrates. Non-specific binding values varied widely (0.4-2.8 mg PEG/100 mg DM tannin-free substrate) when the tannin-free substrate was changed from wheat straw to either rye grass or maize shoots. We therefore propose a modified radiolabelled PEG-binding method to estimate the level of PEG-binding (PEGb) to tannin-containing foliage without using tannin-free substrate to correct for non-specific binding. In this approach, incremental levels of each tanniniferous substrate were used to generate PEGb values. The resultant linear response was analysed and tannin activity was expressed as the slope of the response curve (PEGbSlope) observed for each substrate. The slope takes into account the non-specific binding in each substrate, thus PEGbSlope does not require correction for NSB using tannin-free samples. This approach improved the correlation between PEGb and the {sup 125}I-labelled bovine serum albumin precipitation assay. Relationships between the modified PEG-binding assay and radiolabelled bovine serum albumin assay, in vitro tannin bioassay and colorimetric assays are presented. (author)

  9. Bioactive poly(ethylene glycol) hydrogels to recapitulate the HSC niche and facilitate HSC expansion in culture.

    Science.gov (United States)

    Cuchiara, Maude L; Coşkun, Süleyman; Banda, Omar A; Horter, Kelsey L; Hirschi, Karen K; West, Jennifer L

    2016-04-01

    Hematopoietic stem cells (HSCs) have been used therapeutically for decades, yet their widespread clinical use is hampered by the inability to expand HSCs successfully in vitro. In culture, HSCs rapidly differentiate and lose their ability to self-renew. We hypothesize that by mimicking aspects of the bone marrow microenvironment in vitro we can better control the expansion and differentiation of these cells. In this work, derivatives of poly(ethylene glycol) diacrylate hydrogels were used as a culture substrate for hematopoietic stem and progenitor cell (HSPC) populations. Key HSC cytokines, stem cell factor (SCF) and interferon-γ (IFNγ), as well as the cell adhesion ligands RGDS and connecting segment 1 were covalently immobilized onto the surface of the hydrogels. With the use of SCF and IFNγ, we observed significant expansion of HSPCs, ∼97 and ∼104 fold respectively, while maintaining c-kit(+) lin(-) and c-kit(+) Sca1(+) lin(-) (KSL) populations and the ability to form multilineage colonies after 14 days. HSPCs were also encapsulated within degradable poly(ethylene glycol) hydrogels for three-dimensional culture. After expansion in hydrogels, ∼60% of cells were c-kit(+), demonstrating no loss in the proportion of these cells over the 14 day culture period, and ∼50% of colonies formed were multilineage, indicating that the cells retained their differentiation potential. The ability to tailor and use this system to support HSC growth could have implications on the future use of HSCs and other blood cell types in a clinical setting. © 2015 Wiley Periodicals, Inc.

  10. In vitro and in vivo effects of polyethylene glycol (PEG-modified lipid in DOTAP/cholesterol-mediated gene transfection

    Directory of Open Access Journals (Sweden)

    Torben Gjetting

    2010-05-01

    Full Text Available Torben Gjetting1, Nicolai Skovbjerg Arildsen1, Camilla Laulund Christensen1, Thomas Tuxen Poulsen1, Jack A Roth3, Vagn Neerup Handlos2, Hans Skovgaard Poulsen11Department of Radiation Biology, Finsen Center, 2RH Pharmacy, Copenhagen University Hospital, Copenhagen, Denmark; 3Thoracic Medical Oncology, MD Anderson Cancer Centre, Houston, TX, USABackground: 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 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.Method: A direct comparison of properties in vitro and in vivo of 4 different DOTAP/cholesterol-based lipoplexes containing 0%, 2%, 4%, and 10% PEG was performed using reporter gene activity and radioactive tracer lipid markers to monitor biodistribution.Results: We found that 10% PEGylation of lipoplexes caused reduced retention in lung and heart tissues of nude mice compared to nonPEGylated lipoplexes, however no significant delivery to xenograft flank tumors was observed. Although PEGylated and nonPEGylated lipoplexes were delivered to cells the ability to mediate successful transfection is hampered upon PEGylation, presumably due to a changed uptake mechanism and intracellular processing.Conclusion: The eminent in vivo transfection potency of DOTAP/cholesterol-based lipoplexes is well established for expression in lung tumors, but it is unsuitable for expression in non first pass organs such as xenograft flank tumors in mice even after addition of a PEG-lipid in the formulation.Keywords: gene delivery, DOTAP, polyethylene glycol (PEG, biodistribution, lung cancer, xenograft tumor model

  11. Covalently immobilized platelet-derived growth factor-BB promotes angiogenesis in biomimetic poly(ethylene glycol) hydrogels

    Science.gov (United States)

    Saik, Jennifer E.; Gould, Daniel J.; Watkins, Emily M.; Dickinson, Mary E.; West, Jennifer L.

    2011-01-01

    The field of tissue engineering is severely limited by a lack of microvascularization in tissue engineered constructs. Biomimetic poly(ethylene glycol) hydrogels containing covalently immobilized platelet-derived growth factor BB (PDGF-BB) were developed to promote angiogenesis. Poly(ethylene glycol) hydrogels resist protein absorption and subsequent non-specific cell adhesion, thus providing a “blank slate”, which can be modified through the incorporation of cell adhesive ligands and growth factors. PDGF-BB is a key angiogenic protein able to support neovessel stabilization by inducing functional anastomoses and recruiting pericytes. Due to the widespread effects of PDGF in the body and a half-life of only 30 min in circulating blood, immobilization of PDGF-BB may be necessary. In this work bioactive, covalently immobilized PDGF-BB was shown to induce tubulogenesis on two-dimensional modified surfaces, migration in three-dimensional (3D) degradable hydrogels and angiogenesis in a mouse cornea micro-pocket angiogenesis assay. Covalently immobilized PDGF-BB was also used in combination with covalently immobilized fibroblast growth factor-2, which led to significantly increased endothelial cell migration in 3D degradable hydrogels compared with the presentation of each factor alone. When a co-culture of endothelial cells and mouse pericyte precursor 10T1/2 cells was seeded onto modified surfaces tubule formation was independent of surface modifications with covalently immobilized growth factors. Furthermore, the combination of soluble PDGF-BB and immobilized PDGF-BB induced a more robust vascular response compared with soluble PDGF-BB alone when implanted into an in vivo mouse cornea micropocket angiogenesis assay. Based on these results, we believe bioactive hydrogels can be tailored to improve the formation of functional microvasculature for tissue engineering. PMID:20801242

  12. Self-assembled poly(ethylene glycol)-co-acrylic acid microgels to inhibit bacterial colonization of synthetic surfaces.

    Science.gov (United States)

    Wang, Qichen; Uzunoglu, Emel; Wu, Yong; Libera, Matthew

    2012-05-01

    We explored the use of self-assembled microgels to inhibit the bacterial colonization of synthetic surfaces both by modulating surface cell adhesiveness at length scales comparable to bacterial dimensions (∼1 μm) and by locally storing/releasing an antimicrobial. Poly(ethylene glycol) [PEG] and poly(ethylene glycol)-co-acrylic acid [PEG-AA] microgels were synthesized by suspension photopolymerization. Consistent with macroscopic gels, a pH dependence of both zeta potential and hydrodynamic diameter was observed in AA-containing microgels but not in pure PEG microgels. The microgels were electrostatically deposited onto poly(l-lysine) (PLL) primed silicon to form submonolayer surface coatings. The microgel surface density could be controlled via the deposition time and the microgel concentration in the parent suspension. In addition to their intrinsic antifouling properties, after deposition, the microgels could be loaded with a cationic antimicrobial peptide (L5) because of favorable electrostatic interactions. Loading was significantly higher in PEG-AA microgels than in pure PEG microgels. The modification of PLL-primed Si by unloaded PEG-AA microgels reduced the short-term (6 h) S. epidermidis surface colonization by a factor of 2, and the degree of inhibition increased when the average spacing between microgels was reduced. Postdeposition L5 peptide loading into microgels further reduced bacterial colonization to the extent that, after 10 h of S. epidermidis culture in tryptic soy broth, the colonization of L5-loaded PEG-AA microgel-modified Si was comparable to the very small level of colonization observed on macroscopic PEG gel controls. The fact that these microgels can be deposited by a nonline-of-sight self-assembly process and hinder bacterial colonization opens the possibility of modifying the surfaces of topographically complex biomedical devices and reduces the rate of biomaterial-associated infection.

  13. Oxidation-Responsive and "Clickable" Poly(ethylene glycol) via Copolymerization of 2-(Methylthio)ethyl Glycidyl Ether.

    Science.gov (United States)

    Herzberger, Jana; Fischer, Karl; Leibig, Daniel; Bros, Matthias; Thiermann, Raphael; Frey, Holger

    2016-07-27

    Poly(ethylene glycol) (PEG) is a widely used biocompatible polymer. We describe a novel epoxide monomer with methyl-thioether moiety, 2-(methylthio)ethyl glycidyl ether (MTEGE), which enables the synthesis of well-defined thioether-functional poly(ethylene glycol). Random and block mPEG-b-PMTEGE copolymers (Mw/Mn = 1.05-1.17) were obtained via anionic ring opening polymerization (AROP) with molecular weights ranging from 5 600 to 12 000 g·mol(-1). The statistical copolymerization of MTEGE with ethylene oxide results in a random microstructure (rEO = 0.92 ± 0.02 and rMTEG E = 1.06 ± 0.02), which was confirmed by in situ (1)H NMR kinetic studies. The random copolymers are thermoresponsive in aqueous solution, with a wide range of tunable transition temperatures of 88 to 28 °C. In contrast, mPEG-b-PMTEGE block copolymers formed well-defined micelles (Rh ≈ 9-15 nm) in water, studied by detailed light scattering (DLS and SLS). Intriguingly, the thioether moieties of MTEGE can be selectively oxidized into sulfoxide units, leading to full disassembly of the micelles, as confirmed by detection of pure unimers (DLS and SLS). Oxidation-responsive release of encapsulated Nile Red demonstrates the potential of these micelles as redox-responsive nanocarriers. MTT assays showed only minor effects of the thioethers and their oxidized derivatives on the cellular metabolism of WEHI-164 and HEK-293T cell lines (1-1000 μg·mL(-1)). Further, sulfonium PEG polyelectrolytes can be obtained via alkylation or alkoxylation of MTEGE, providing access to a large variety of functional groups at the charged sulfur atom.

  14. in vivo degradation of polyurethane foam with 55 wt % polyethylene glycol

    NARCIS (Netherlands)

    Broekema, Ferdinand I.; van Leeuwen, M. Barbara M.; Van Minnen, Baucke; Bos, Rudolf R. M.

    2015-01-01

    Most topical hemostatic agents are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission while adjustments in the production process of these materials are limited. A synthetic hemostatic agent based on polyurethane (PU) and polyethylene g

  15. in vivo degradation of polyurethane foam with 55 wt % polyethylene glycol

    NARCIS (Netherlands)

    Broekema, Ferdinand I.; van Leeuwen, M. Barbara M.; Van Minnen, Baucke; Bos, Rudolf R. M.

    2015-01-01

    Most topical hemostatic agents are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission while adjustments in the production process of these materials are limited. A synthetic hemostatic agent based on polyurethane (PU) and polyethylene g

  16. Poly(ethylene glycol) (PEG) in a Polyethylene (PE) Framework: A Simple Model for Simulation Studies of a Soluble Polymer in an Open Framework.

    Science.gov (United States)

    Xie, Liangxu; Chan, Kwong-Yu; Quirke, Nick

    2017-08-16

    Canonical molecular dynamics simulations are performed to investigate the behavior of single-chain and multiple-chain poly(ethylene glycol) (PEG) contained within a cubic framework spanned by polyethylene (PE) chains. This simple model is the first of its kind to study the chemical physics of polymer-threaded organic frameworks, which are materials with potential applications in catalysis and separation processes. For a single-chain 9-mer, 14-mer, and 18-mer in a small framework, the PEG will interact strongly with the framework and assume a more linear geometry chain with an increased radius of gyration Rg compared to that of a large framework. The interaction between PEG and the framework decreases with increasing mesh size in both vacuum and water. In the limit of a framework with an infinitely large cavity (infinitely long linkers), PEG behavior approaches simulation results without a framework. The solvation of PEG is simulated by adding explicit TIP3P water molecules to a 6-chain PEG 14-mer aggregate confined in a framework. The 14-mer chains are readily solvated and leach out of a large 2.6 nm mesh framework. There are fewer water-PEG interactions in a small 1.0 nm mesh framework, as indicated by a smaller number of hydrogen bonds. The PEG aggregate, however, still partially dissolves but is retained within the 1.0 nm framework. The preliminary results illustrate the effectiveness of the simple model in studying polymer-threaded framework materials and in optimizing polymer or framework parameters for high performance.

  17. Modification of hydrophobic acrylic intraocular lens with poly(ethylene glycol) by atmospheric pressure glow discharge: A facile approach

    Energy Technology Data Exchange (ETDEWEB)

    Lin Lin; Wang Yao; Huang Xiaodan [Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China); Xu Zhikang [Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Yao Ke, E-mail: xlren@zju.edu.cn [Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China)

    2010-10-01

    To improve the anterior surface biocompatibility of hydrophobic acrylic intraocular lens (IOL) in a convenient and continuous way, poly(ethylene glycol)s (PEGs) were immobilized by atmospheric pressure glow discharge (APGD) treatment using argon as the discharge gas. The hydrophilicity and chemical changes on the IOL surface were characterized by static water contact angle and X-ray photoelectron spectroscopy to confirm the covalent binding of PEG. The morphology of the IOL surface was observed under field emission scanning electron microscopy and atomic force microscopy. The surface biocompatibility was evaluated by adhesion experiments with platelets, macrophages, and lens epithelial cells (LECs) in vitro. The results revealed that the anterior surface of the PEG-grafted IOL displayed significantly and permanently improved hydrophilicity. Cell repellency was observed, especially in the PEG-modified IOL group, which resisted the attachment of platelets, macrophages and LECs. Moreover, the spread and growth of cells were suppressed, which may be attributed to the steric stabilization force and chain mobility effect of the modified PEG. All of these results indicated that hydrophobic acrylic IOLs can be hydrophilic modified by PEG through APGD treatment in a convenient and continuous manner which will provide advantages for further industrial applications.

  18. Polyethylene glycol coated CoFe{sub 2}O{sub 4} nanoparticles: A potential spinel ferrite for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Humbe, Ashok V.; Birajdar, Shankar D.; Jadhav, K. M., E-mail: drjadhavkm@gmail.com [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, (M. S.) (India); Bhandari, J. M. [Department of Physics, Gandhi College, Kada, Ashti, Beed, (M. S.) (India); Waghule, N. N. [Department of Physics, Bhagwan Mahavidyalay, Ashti, Beed, (M. S.) (India); Bhagwat, V. R. [Institute of Shipbuilding Technology, Bogda-Vasco, Goa (India)

    2015-06-24

    The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe{sub 2}O{sub 4}) nanoparticles have been reported in the present study. CoFe{sub 2}O{sub 4} nanoparticles were prepared by sol-gel auto-combustion method using citric acid + ethylene glycol as a fuel. The prepared powder of cobalt ferrite nanoparticles was annealed at 600°C for 6h and used for further study. The structural characterization of CoFe{sub 2}O{sub 4} nanoparticles were carried out by X-ray diffraction technique. The X-ray analysis confirmed the formation of single phase cubic spinel structure. The crystallite size, Lattice constant and X-ray density of the PEG coated CoFe{sub 2}O{sub 4} nanoparticles were calculated by using XRD data. The presence of PEG on CoFe{sub 2}O{sub 4} nanoparticles and reduced agglomeration in the CoFe{sub 2}O{sub 4} nanoparticles were revealed by SEM studies. The magnetic properties were studied by pulse field hysteresis loop tracer technique at a room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, coercivity etc have been obtained. These magnetic parameters were get decreased by PEG coating.

  19. Improving amphiphilic polypropylenes by grafting poly(vinylpyrrolidone) and poly(ethylene glycol) methacrylate segments on a polypropylene microporous membrane

    Science.gov (United States)

    Chen, Huirong; Ma, Wenzhong; Xia, Yanping; Gu, Yi; Cao, Zheng; Liu, Chunlin; Yang, Haicun; Tao, Shengxi; Geng, Haoran; Tao, Guoliang; Matsuyama, Hideto

    2017-10-01

    An amphiphilic polypropylene-g-poly[vinylpyrrolidone-co-poly(ethylene glycol) methacrylate] (PP-g-(NVP-co-PEGMA)) modifier was prepared by melt grafting polymerization using N-vinyl pyrrolidone (NVP) as the grafting monomer and poly(ethylene glycol) (PEGMA) as the comonomer. Fourier transform infrared (FTIR) spectroscopy and elemental analysis showed that the hydrophilic branched chains (NVP-g-PEGMA) were successfully grafted to polypropylene (PP) macromolecular chains. The largest NVP grafting degree for PP-g-(NVP-co-PEGMA) (up to 20.4%) was obtained when the mass ratio of PP/NVP/PEGMA was 100/30/15. Hydrophilic PP microporous membranes were prepared by stretching cast films of PP/PP-g-(NVP-co-PEGMA) blends. The membrane thermostability (including the modifier) was better than that of the pure PP membrane with a similar surface pore structure. The porosity of the modified membranes was only slightly lower than that of the pure PP membranes. Contact angle measurements were used to examine the hydrophilicity of the membranes. The water contact angle of the membranes decreased when PP-g-(NVP-co-PEGMA) was added, and the minimum contact angle was 64.5°. Therefore, this work provides a good application for stretched hydrophilic PP membrane fabrication.

  20. Enhancing the in vivo transdermal delivery of gold nanoparticles using poly(ethylene glycol and its oleylamine conjugate

    Directory of Open Access Journals (Sweden)

    Hsiao PF

    2016-05-01

    Full Text Available Pa Fan Hsiao,1–3 Sydney Peng,4 Ting-Cheng Tang,4 Shuian-Yin Lin,5 Hsieh-Chih Tsai4 1Department of Dermatology, Mackay Memorial Hospital, 2Mackay Medicine, Nursing and Management College, 3Mackay Medical College, New Taipei City, 4Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 5National Applied Research Laboratories, Instrument Technology Research Center, Hsinchu, Taiwan Abstract: In this study, we investigated the effect of (ethylene glycol (PEG and PEG–oleylamine (OAm functionalization on the skin permeation property of gold nanoparticles (GNS in vivo. Chemisorption of polymers onto GNS was verified by a red shift in the ultraviolet–visible spectrum as well as by a change in the nanoparticle surface charge. The physicochemical properties of pristine and functionalized nanoparticles were analyzed by ultraviolet–visible spectroscopy, zeta potential analyzer, and transmission electron microscopy. Transmission electron microscopy revealed that the interparticle distance between nanoparticles increased after GNS functionalization. Comparing the skin permeation profile of pristine and functionalized GNS, the follicular deposition of GNS increased twofold after PEG–OAm functionalization. Moreover, PEG- and PEG–OAm-functionalized nanoparticles were able to overcome the skin barrier and deposit in the deeper subcutaneous adipose tissue. These findings demonstrate the potential of PEG- and PEG–OAm-functionalized GNS in serving a multitude of applications in transdermal pharmaceuticals. Keywords: skin penetration, amphiphilic copolymer, gold nanoparticle, oleylamine, poly(ethylene glycol

  1. Strategies for creating antifouling surfaces using selfassembled poly(ethylene glycol) thiol molecules

    DEFF Research Database (Denmark)

    Lokanathan, Arcot R.

    2011-01-01

    conditions for the reversible, initial attachment of microbial cells. This effect can be obtained by grafting hydrophilic polymeric chains onto surfaces and thereby provide a steric barrier between the substrate surface and the microbial cell. Poly (ethylene glycol) (PEG) is one of the most widely used....... The work focuses on novel strategies to self assemble PEG thiol monolayers with high graft density. One of the strategies investigated involved backfilling a self assembled layer of 2000 Da PEG thiol with shorter oligo (ethylene glycol) (OEG) thiol molecules to form a mixed monolayer. Detailed quantitative......Microorganisms are one of the most important parts of our ecosystem influencing the sustenance of human society. The beneficial microbes are of high relevance to food industry, development of antibiotics and processing of many raw materials. Mankind has indeed benefitted a lot from large number...

  2. IMMOBILIZATION OF POTENTIALLY BIOACTIVE MOIETIES ONTO POLYETHER WITH POLY(ETHYLENE GLYCOL)-SULFONATE SPACER

    Institute of Scientific and Technical Information of China (English)

    JI Jian; FENG Linxian; QIU Yongxin; YU Xiaojie; YANG Shilin

    1997-01-01

    A new reactive graft copolymer, poly(tetramethylene glycol)-graft-ω-propyl sodium sulfonate-poly(ethylene glycol) (PTMG-g-PEG-CH2CH2CH2SO-3Na+), was synthesized by the cationic polymerization of α-ω-bifunctional PEG macromonomer ((o)CH2-PEG--CH2CH2CH2SO3Na ) and THF. The obtained copolymer exhibits the expected structure as indicated by the result of characterization. Two amino acids (L-arginine, L-tyrosine) were covalently attached to the copolymer after converting the sulfonate group to sulfonyl chloride. So the new reactive graft copolymer (PTMG-g-PEG-CH2CH2CH2SO-3Na+) is expected to be very useful in attachment of potentially bioactive moieties to polymer via a hydrophilic PEG spacer.

  3. Thermal properties and physicochemical behavior in aqueous solution of pyrene-labeled poly(ethylene glycol-polylactide conjugate

    Directory of Open Access Journals (Sweden)

    Chen WL

    2015-04-01

    Full Text Available Wei-Lin Chen,1,2 Yun-Fen Peng,1,3 Sheng-Kuo Chiang,1 Ming-Hsi Huang1–3 1National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan; 2Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan; 3PhD Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, Taichung, Taiwan Abstract: A fluorescence-labeled bioresorbable polymer was prepared by a coupling reaction of poly(ethylene glycol-polylactide (PEG-PLA with carboxyl pyrene, using N,N’-diisopropylcarbodiimide/1-hydroxy-7-azabenzotriazole (DIC/HOAt as a coupling agent and 4-dimethylaminopyridine (DMAP as a catalyst. The obtained copolymer, termed PEG-PLA-pyrene, was characterized using various analytical techniques, such as gel permeation chromatography (GPC, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS, proton nuclear magnetic resonance (1H-NMR, infrared spectroscopy (IR, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA, to identify the molecular structure and to monitor the thermal property changes before and after the reaction. The presence of a pyrene moiety at the end of polylactide (PLA did not alter the crystallization ability of the poly(ethylene glycol (PEG blocks, indicating that the conjugate preserved the inherent thermal properties of PEG-PLA. However, the presence of PEG-PLA blocks strongly reduced the melting of pyrene, indicating that the thermal characteristics were sensitive to PEG-PLA incorporation. Regarding the physicochemical behavior in aqueous solution, a higher concentration of PEG-PLA-pyrene resulted in a higher ultraviolet-visible (UV-vis absorbance and fluorescence emission intensity. This is of great interest for the use of this conjugate as a fluorescence probe to study the in vivo distribution as well as the internalization and intracellular localization of polymeric micelles

  4. Mechanical and In Vitro Biocompatibility of Brushite Cement Modified by Polyethylene Glycol

    OpenAIRE

    2012-01-01

    Brushite (dicalcium phosphate dihydrate, DCPD) cement, owing to its high solubility in physiological condition and ability to guide new bone formation, is widely used to treat bone defects. In the present study, we have evaluated the effects of poly ethylene glycol (PEG) addition on the setting time, compressive strength and in vitro biocompatibility of brushite cement. The brushite cements were prepared by mixing β-tricalcium phosphate [β-TCP, Ca3(PO4)2] and monocalcium phosphate monohydrate...

  5. Experimental study of the density and viscosity of polyethylene glycols and their mixtures at temperatures from 293 K to 473 K and at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sagdeev, D.I.; Fomina, M.G.; Mukhamedzyanov, G.Kh. [Kazan State Technological University, Kazan (Russian Federation); Abdulagatov, I.M., E-mail: ilmutdin@boulder.nist.gov [Geothermal Research Institute of the Dagestan Scientific Center of the Russian Academy of Sciences, Makhachkala, Dagestan (Russian Federation)

    2011-12-15

    Highlights: > Viscosity and density of polyethylene glycols. > Combined experimental apparatus for density and viscosity measurements. > Vogel-Tamman-Fulcher model for viscosity. - Abstract: A new apparatus to measure simultaneously the density and viscosity of liquids has been designed and constructed based on the hydrostatic weighing and falling-body principles. The density and viscosity of monoethylene glycol (MEG), diethylene glycol (DEG), and triethylene glycol (TEG) and their binary, (50%MEG + 50%DEG), (50%MEG + 50%TEG), (50%DEG + 50%TEG), and ternary (33.33%MEG + 33.33%DEG + 33.34%TEG) mixtures have been measured over the temperature range from 293 K to 473 K and at atmospheric pressure. The expanded uncertainty of the density, pressure, temperature, and viscosity measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.15% to 0.30%, 0.05%, 0.06 K, and 1.5% to 2.0% (depending on temperature and pressure ranges), respectively. The theoretically based Arrhenius-Andrade and Vogel-Tamman-Fulcher type equations were used to describe the temperature dependence of measured viscosities for pure polyethylene glycols and their mixtures.

  6. Fragment-based solid-phase assembly of oligonucleotide conjugates with peptide and polyethylene glycol ligands.

    Science.gov (United States)

    Dirin, Mehrdad; Urban, Ernst; Noe, Christian R; Winkler, Johannes

    2016-10-04

    Ligand conjugation to oligonucleotides is an attractive strategy for enhancing the therapeutic potential of antisense and siRNA agents by inferring properties such as improved cellular uptake or better pharmacokinetic properties. Disulfide linkages enable dissociation of ligands and oligonucleotides in reducing environments found in endosomal compartments after cellular uptake. Solution-phase fragment coupling procedures for producing oligonucleotide conjugates are often tedious, produce moderate yields and reaction byproducts are frequently difficult to remove. We have developed an improved method for solid-phase coupling of ligands to oligonucleotides via disulfides directly after solid-phase synthesis. A 2'-thiol introduced using a modified nucleotide building block was orthogonally deprotected on the controlled pore glass solid support with N-butylphosphine. Oligolysine peptides and a short monodisperse ethylene glycol chain were successfully coupled to the deprotected thiol. Cleavage from the resin and full removal of oligonucleotide protection groups were achieved using methanolic ammonia. After standard desalting, and without further purification, homogenous conjugates were obtained as demonstrated by HPLC, gel electrophoresis, and mass spectrometry. The attachment of both amphiphilic and cationic ligands proves the versatility of the conjugation procedure. An antisense oligonucleotide conjugate with hexalysine showed pronounced gene silencing in a cell culture tumor model in the absence of a transfection reagent and the corresponding ethylene glycol conjugate resulted in down regulation of the target gene to nearly 50% after naked application. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. In vitro evaluation of the genotoxicity of a family of novel MeO-PEG-poly(D,L-lactic-co-glycolic acid)-PEG-OMe triblock copolymer and PLGA nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    He Lili; Yang Likai; Zhang Zhirong; Gong Tao; Deng Li; Sun Xun [Key Laboratory of Drug Targeting and Novel Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Gu Zhongwei, E-mail: xunsun22@gmail.co [National Engineering Research Center for Biomaterials, Engineering Research Center of Biomaterials, Sichuan University, Chengdu 610064 (China)

    2009-11-11

    Despite the booming development of nanoparticle materials for pharmaceutical applications, studies on their genotoxicity are few. In our previous efforts to develop an intravenous nanoparticle material, a family of novel monomethoxy(polyethylene glycol)-poly(D,L-lactic-co-glycolic acid)-monomethoxy (PELGE) polymers was synthesized. The cytotoxicity and genotoxicity of nine kinds of selected blank PELGE and PLGA (poly(D,L-lactic and glycolic acid)) nanoparticles were evaluated using methyl thiazolyl tetrazolium (MTT), micronucleus (MN) and sister chromatid exchange (SCE) assays with or without the addition of a metabolic activation system (S9 mix), using Chinese hamster ovary (CHO) cells. The cytotoxicity of nanoparticles exhibited a dose-dependent response, with a concentration of 5 mg ml{sup -1} being the turning point. The frequencies of MN observed in samples treated with various nanoparticles were not statistically different from those seen in the negative controls in the presence or absence of the S9 mix. Also, no cell cycle delay was observed. The numbers of SCE per cell observed in samples treated with five kinds of PELGE nanoparticles were significantly greater than those found in the negative controls with or without the S9 mix. The discrepancies found in the two assays suggest that the five kinds of nanoparticles may produce only a weakly clastogenic response.

  8. D-α-tocopherol polyethylene glycol succinate-based derivative nanoparticles as a novel carrier for paclitaxel delivery

    Directory of Open Access Journals (Sweden)

    Wu YP

    2015-08-01

    Full Text Available Yupei Wu,1,* Qian Chu,2,* Songwei Tan,1 Xiangting Zhuang,1 Yuling Bao,1 Tingting Wu,1 Zhiping Zhang1,3,41Tongji School of Pharmacy, 2Department of Oncology, Tongji Hospital, Tongji Medical School, 3Hubei Engineering Research Center for NDDS, 4National Engineering Research Center for Nanomedicine, Huazhong University of Science and Technology, Wuhan, People’s Republic of China*These authors contributed equally to this workAbstract: Paclitaxel (PTX is one of the most effective antineoplastic drugs. Its current clinical administration Taxol® is formulated in Cremophor EL, which causes serious side effects. Nanoparticles (NP with lower systemic toxicity and enhanced therapeutic efficiency may be an alternative formulation of the Cremophor EL-based vehicle for PTX delivery. In this study, novel amphipathic 4-arm-PEG-TPGS derivatives, the conjugation of D-α-tocopherol polyethylene glycol succinate (TPGS and 4-arm-polyethylene glycol (4-arm-PEG with different molecular weights, have been successfully synthesized and used as carriers for the delivery of PTX. These 4-arm-PEG-TPGS derivatives were able to self-assemble to form uniform NP with PTX encapsulation. Among them, 4-arm-PEG5K-TPGS NP exhibited the smallest particle size, highest drug-loading efficiency, negligible hemolysis rate, and high physiologic stability. Therefore, it was chosen for further in vitro and in vivo investigations. Facilitated by the effective uptake of the NP, the PTX-loaded 4-arm-PEG5K-TPGS NP showed greater cytotoxicity compared with free PTX against human ovarian cancer (A2780, non-small cell lung cancer (A549, and breast adenocarcinoma cancer (MCF-7 cells, as well as a higher apoptotic rate and a more significant cell cycle arrest effect at the G2/M phase in A2780 cells. More importantly, PTX-loaded 4-arm-PEG5K-TPGS NP resulted in a significantly improved tumor growth inhibitory effect in comparison to Taxol® in S180 sarcoma-bearing mice models. This study suggested

  9. Synthesis, Characterization and renal toxicity of ZnO and polyethylene glycol Coated ZnO nanoparticles

    Directory of Open Access Journals (Sweden)

    Banafsheh Raisi Dehkourdi

    2017-01-01

    Full Text Available Objective(s: The wide scale use of Zinc oxide nanoparticles (ZnO NPs in the consumer market world makes human beings more prone to the exposure to ZnO nanoparticles and its adverse effects. Therefore, the aim of the present study is to assess renal toxicity potential of ZnO and Polyethylene glycol Coated ZnO Nanoparticles in rat.Materials and Methods: Co-precipitation chemical method was used in order to synthesize ZnO nanoparticles. The synthesized nanoparticles were coated with PEG (Polyethylene glycol and the coating interactions were investigated by FTIR (Fourier Transform Infrared Spectroscopy. Structural properties of ZnO NPs were evaluated by TEM (Transmission Electron Microscope and XRD (X Ray Diffraction. Toxicity assessment of ZnO and PEG coated ZnO nanoparticles were studied in rat by intra peritoneal injections during a one-month. Renal factors (Creatinine, Uric acid and Blood Urea Nitrogen were measured 15 and 30 days post injection.Results: The synthesized nanoparticles were single phase and have spinel structure. Their size distribution was around 18 nm. Some kidney factors were changed due to the injection of both uncoated and coated nanoparticles (especially in groups received concentrations of more than 100 mg per kg of body weight. Renal factors changes were more considerable in groups received ZnO NPs in comparison with those received PEG coated ZnO NPs. Chemical toxicity studies showed that there was no irreversible effect in the groups received  concentrations less than 200 mg/kg (mg per kg of body weight.Conclusion: The results indicated that renal factors were changed during 15 days post injection, especially in groups received high doses (200 mg/kg. The results of measurements 30 days post injection showed less change in comparison with the control and this indicates that there was no irreversible effect on kidney. Moreover, PEG coated nanoparticles were less toxic in comparison with Uncoated ZnO NPs.

  10. Synthesis and characterization of polyethylene glycol (PEG) coated Fe3O4 nanoparticles by chemical co-precipitation method for biomedical applications.

    Science.gov (United States)

    Anbarasu, M; Anandan, M; Chinnasamy, E; Gopinath, V; Balamurugan, K

    2015-01-25

    Polyethylene glycol (PEG) coated Fe3O4 nanoparticles were synthesized by chemical co-precipitation method. With polyethylene glycol (PEG) as a stabilizer and dispersant. The X-ray diffraction and selected area electron diffraction (SAED) results show that the cubic inverse spinel structure of pure phase polycrystalline Fe3O4 was obtained. The scanning electron microscopy (SEM) and field emission transmission electron microscopy (FE-TEM) results exhibited that the resulted Fe3O4 nanoparticles were roughly spherical in shape with narrow size distribution and homogenous shape. Fourier transform infrared spectroscopy (FT-IR) results suggested that PEG indicated with Fe3O4 via its carbonyl groups. Results of vibrating sample magnetometer (VSM) indicated that the prepared Fe3O4 nanoparticles exhibit superparamagnetic behavior and high saturation magnetization at room temperature. Such Fe3O4 nanoparticles with favorable size and tunable magnetic properties are promising biomedical applications.

  11. Preparation and in vitro characterization of dexamethasone-loaded poly(D,L-lactic acid) microspheres embedded in poly(ethylene glycol)-poly({varepsilon}-caprolactone)-poly(ethylene glycol) hydrogel for orthopedic tissue engineering.

    Science.gov (United States)

    Fan, Min; Guo, QingFa; Luo, JingCong; Luo, Feng; Xie, Ping; Tang, XiaoHai; Qian, ZhiYong

    2013-08-01

    The corium is decreased to about half of its thickness in skin defects and wrinkles due to gravity and environment. In this study, dexamethasone/poly(d,l-lactic acid) (Mn = 160,000) microspheres were incorporated into poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (Mn = 3300) hydrogel to prepare an injectable hydrogel composite. The composite was designed to increase the thickness of the corium. Dexamethasone/poly(d,l-lactic acid) microspheres were prepared by oil-in-water emulsion/solvent evaporation technique. The properties of microspheres were investigated by size distribution measurement, scanning electron microscope and x-ray diffraction. Drug loading, encapsulation efficiency, and drug delivery behavior of microspheres were also studied in detail. Cell adhesion of microspheres was investigated by NIH3T3 cell in vitro. The properties of hydrogel composite were investigated by scanning electron microscope, rheological measurements and methyl thiazolyl tetrazolium assay. Drug release from composite was determined by HPLC-UV analysis. These results suggested that poly(d,l-lactic acid) microspheres encapsulating dexamethasone embedded in poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) hydrogel might have prospective application in orthopedic tissue engineering field.

  12. RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells

    OpenAIRE

    Nazli C; Ergenc TI; Yar Y; Acar HY; Kizilel S

    2012-01-01

    © 2012 Nazli et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited. International Journal of Nanomedicine 2012:7 1903–1920 International Journal of Nanomedicine RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells Caner Nazli1 Tugba Ipek Ergenc2 Yasemin Ya...

  13. Controllable biosynthesis of high-purity lead-sulfide (PbS) nanocrystals by regulating the concentration of polyethylene glycol in microbial system.

    Science.gov (United States)

    Yue, Lei; Wang, Jia; Zhang, Yongtao; Qi, Shiyue; Xin, Baoping

    2016-12-01

    We demonstrated a simple biological method to explore the controllable synthesize of high-purity PbS nanocrystals by regulating the concentration of polyethylene glycol in microbial system. The biogenic H2S produced via the reduction of sulfate precipitated Pb(2+) ions as sulfide extracellularly, and the optimal removal rate of Pb(2+) ions is up to 96.7 % in 2 weeks. The characterization results showed that PbS nanocuboids with a particle size 50 × 50 × 100 nm obtained from Case A with 4 mM polyethylene glycol as a dispersant, and can completely degrade methylene blue from solution within 20 h; PbS nanosheets with a thickness size ca. 10 nm attained from Case B with 12 mM polyethylene glycol, and it can degrade 61.6 % dye within 24 h; PbS nanoparticles with a uniform diameter of ca. 60 nm formed from Case C with 20 mM polyethylene glycol, only degrade 14.1 % dye within 24 h. It is interesting that the factor affecting their catalytic activities is not the specific surface area, but the number of [200] crystal plane. This work not only displayed a simple synthetic method to control the morphology of PbS nanocrystals in microbial system, but also provided an economic and environmentally friendly approach for resourceful treatment and efficient bioremediation of wastewater-containing heavy metal.

  14. A peptide functionalized poly(ethylene glycol) (PEG) hydrogel for investigating the influence of biochemical and biophysical matrix properties on tumor cell migration

    OpenAIRE

    Singh, Samir P.; Schwartz, Michael P.; Lee, Justin Y.; Fairbanks, Benjamin D.; Kristi S Anseth

    2014-01-01

    To address the challenges associated with defined control over matrix properties in 3D cell culture systems, we employed a peptide functionalized poly(ethylene glycol) (PEG) hydrogel matrix in which mechanical modulus and adhesive properties were tuned. An HT-1080 human fibrosarcoma cell line was chosen as a model for probing matrix influences on tumor cell migration using the PEG hydrogel platform. HT-1080 speed varied with a complex dependence on both matrix modulus and Cys-Arg-Gly-Asp-Ser ...

  15. To immobilize polyethylene glycol-borate ester/lithium fluoride in graphene oxide/poly(vinyl alcohol) for synthesizing new polymer electrolyte membrane of lithium-ion batteries

    OpenAIRE

    Huang, Y.F.; Zhang, M. Q.; M. Z. Rong; W. H. Ruan

    2017-01-01

    Polymer electrolyte membranes (PEMs) are potentially applicable in lithium-ion batteries with high safety, low cost and good performance. Here, to take advantages of ionic conductivity and selectivity of borate ester-functionalized small molecules as well as structural properties of polymer nanocomposite, a strategy of immobilizing as-synthesized polyethylene glycol-borate ester/lithium fluoride (B-PEG/LiF) in graphene oxide/poly(vinyl alcohol) (GO/PVA) to prepare a PEM is put forward. Chemic...

  16. A 3D Poly(ethylene glycol)-based Tumor Angiogenesis Model to Study the Influence of Vascular Cells on Lung Tumor Cell Behavior

    OpenAIRE

    Laila C. Roudsari; Jeffs, Sydney E.; Witt, Amber S.; Gill, Bartley J.; West, Jennifer L.

    2016-01-01

    Tumor angiogenesis is critical to tumor growth and metastasis, yet much is unknown about the role vascular cells play in the tumor microenvironment. In vitro models that mimic in vivo tumor neovascularization facilitate exploration of this role. Here we investigated lung adenocarcinoma cancer cells (344SQ) and endothelial and pericyte vascular cells encapsulated in cell-adhesive, proteolytically-degradable poly(ethylene) glycol-based hydrogels. 344SQ in hydrogels formed spheroids and secreted...

  17. Thermodynamics of the sorption of organic compounds on polyethylene glycol 400-permethylated β-cyclodextrin stationary phase and its enantioselectivity in gas chromatography

    Science.gov (United States)

    Kuraeva, Yu. G.; Onuchak, L. A.; Evdokimova, M. A.

    2016-08-01

    The thermodynamic characteristics of sorption of 24 organic compounds of various classes from the gas phase on the binary stationary phase based on polyethylene glycol 400 and permethylated β-cyclodextrin were determined. The influence of geometrical structure and optical activity of organic compounds on the possibility of forming sorbate-macrocycle complexes was examined. It was found that the studied stationary phase shows the enantioselectivity towards low-polar terpenes under the conditions of gas chromatography.

  18. (Vapor + liquid) equilibria for the {l_brace}water + poly(ethylene glycol diacetyl ether) (PEGDAE) and methanol + PEGDAE{r_brace} systems

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Doo-hwan [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, SAN 56-1, Shilim-Dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Lee, Joonwoo [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, SAN 56-1, Shilim-Dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Im, Jihoon [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, SAN 56-1, Shilim-Dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Hwayong [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, SAN 56-1, Shilim-Dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of)]. E-mail: hwayongk@snu.ac.kr

    2007-03-15

    We measured binary (vapor + liquid) equilibrium data for the {l_brace}water + poly(ethylene glycol diacetyl ether) (PEGDAE) and methanol + PEGDAE{r_brace} systems at pressures up to 400 kPa and temperatures from 333 K to 393 K. A static apparatus was used in this study. The measured data were correlated by the Peng-Robinson equation of state using the Wong-Sandler mixing rules with NRTL as the excess Gibbs free energy model.

  19. Polyethylene glycol(PEG-400): An efficient and recyclable reaction medium for the synthesis of novel 1,5-benzodiazepines and their antimicrobial activity

    Institute of Scientific and Technical Information of China (English)

    Shankaraiah G. Konda; Baseer M. Shaikh; Sanjay A. Chavan; Bhaskar S. Dawane

    2011-01-01

    A new series of imidazole-containing 1,5-benzodiazepines have been synthesized by the condensation of chalcones with ophenylenediamine using piperidine in polyethylene glycol(PEG-400)as an efficient and green reaction solvent.The advantages of this protocol are environmental friendliness,easy work-up,high yields,mild reaction condition and avoidance of expensive catalyst.Furthermore,newly synthesized compounds were evaluated for their antimicrobial activity.

  20. 异端基遥爪聚乙二醇的合成%Synthesis of hetero telechelic poly(ethylene glycol)

    Institute of Scientific and Technical Information of China (English)

    杨钊; 郝建原

    2012-01-01

    采用3种新式引发剂,即2-(苄氧基)乙醇钾、2-(四氢-2H-吡喃-2-氧基)乙醇钾、单丙烯基乙二醇钾引发环氧乙烷阴离子开环聚合,反应条件为25℃、48 h、醇与萘钾摩尔比例1∶1,得到3种异端基遥爪聚乙二醇。以2-(苄氧基)乙醇钾引发聚合所得产物为起始物,经一系列反应,得到两种两端均为活性基团的异端基遥爪聚乙二醇,这种方法具有普适性。通过1HNMR及GPC手段,表征了产物的结构、分子量及分子量分布。结果表明可以得到高产率、分子量可控且分布窄的异端基遥爪聚乙二醇。%Three hetero telechelic poly(ethylene glycol)s were obtained via anionic ring-opening polymerization of ethylene oxide using three new initiators :2-(benzyloxy)ethanol potassium、 2-(tetrahydro-2H-pyran-2-yloxy)ethanol potassium,2-allyloxyethanol potassium.The polymerization conditions were as follows:25 ℃,48 h,with equal ethanol and potassium naphthalene feeds.Using the polymerized product from 2-(benzyloxy)ethanol potassium as the start substance,two hetero telechelic poly(ethylene glycol)s with two functional end groups were synthesized through a series of reactions,the method was widely applicable to synthesizing hetero telechelic poly(ethylene glycol)s.The chemical structure,weight average molecular weight and distribution of the resultant products were characterized by 1H-NMR and GPC.The hetero telechelic poly(ethylene glycol)s that have high yields and controlled molecular weights and molecular weight distributions were obtained.

  1. Physicochemical characterisation, drug polymer dissolution and in vitro evaluation of phenacetin and phenylbutazone solid dispersions with polyethylene glycol 8000.

    Science.gov (United States)

    Khan, Sheraz; Batchelor, Hannah; Hanson, Peter; Perrie, Yvonne; Mohammed, Afzal R

    2011-10-01

    Poor water solubility leads to low dissolution rate and consequently, it can limit bioavailability. Solid dispersions, where the drug is dispersed into an inert, hydrophilic polymer matrix can enhance drug dissolution. Solid dispersions were prepared using phenacetin and phenylbutazone as model drugs with polyethylene glycol (PEG) 8000 (carrier), by melt fusion method. Phenacetin and phenylbutazone displayed an increase in the dissolution rate when formulated as solid dispersions as compared with their physical mixture and drug alone counterparts. Characterisation of the solid dispersions was performed using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). DSC studies revealed that drugs were present in the amorphous form within the solid dispersions. FTIR spectra for the solid dispersions of drugs suggested that there was a lack of interaction between PEG 8000 and the drug. However, the physical mixture of phenacetin with PEG 8000 indicated the formation of hydrogen bond between phenacetin and the carrier. Permeability of phenacetin and phenylbutazone was higher for solid dispersions as compared with that of drug alone across Caco-2 cell monolayers. Permeability studies have shown that both phenacetin and phenylbutazone, and their solid dispersions can be categorised as well-absorbed compounds.

  2. A highly sensitive biosensor for tumor maker alpha fetoprotein based on poly(ethylene glycol) doped conducting polymer PEDOT.

    Science.gov (United States)

    Cui, Min; Song, Zhiling; Wu, Yumin; Guo, Bing; Fan, Xiaojian; Luo, Xiliang

    2016-05-15

    Biocompatible polymers, such as poly(ethylene glycol) (PEG), are of great significance in the development of bio-interfaces and biosensors, as they possess excellent biocompatibility and are easy for modification. A novel highly biocompatible polymer composite was synthesized herein through electrochemical polymerization of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and a PEG derivative, 4-arm PEG terminated with thiol groups. The electrodeposited conducting polymer composite of PEG doped PEDOT (PEDOT/PEG) exhibited flake-like nanostructure, large surface area and outstanding stability. In order to further immobilize antibodies, gold nanoparticles (AuNPs) were introduced to the PEDOT/PEG composite surface through their unique interaction with the thiol groups. AuNPs modified PEDOT/PEG provided a desirable support for the immobilization of various biomolecules such as antibodies for alpha fetoprotein (AFP), a vital tumor biomarker for liver cancer. The fabricated AFP biosensor demonstrated favorable selectivity, high sensitivity, and ultralow detection limit. Furthermore, owing to the presence of PEG polymers that are highly hydrophilic, such AuNPs/PEDOT/PEG based AFP biosensor also exhibited good anti-fouling ability, and it was capable of assaying target AFP in 10% (V/V) human serum samples, indicating highly feasible potential for clinical diagnosis.

  3. Length-scale mediated adhesion and directed growth of neural cells by surface-patterned poly(ethylene glycol) hydrogels.

    Science.gov (United States)

    Krsko, Peter; McCann, Thomas E; Thach, Thu-Trang; Laabs, Tracy L; Geller, Herbert M; Libera, Matthew R

    2009-02-01

    We engineered surfaces that permit the adhesion and directed growth of neuronal cell processes but that prevent the adhesion of astrocytes. This effect was achieved based on the spatial distribution of sub-micron-sized cell-repulsive poly(ethylene glycol) [PEG] hydrogels patterned on an otherwise cell-adhesive substrate. Patterns were identified that promoted cellular responses ranging from complete non-attachment, selective attachment, and directed growth at both cellular and subcellular length scales. At the highest patterning density where the individual hydrogels almost overlapped, there was no cellular adhesion. As the spacing between individual hydrogels was increased, patterns were identified where neurites could grow on the adhesive surface between hydrogels while astrocytes were unable to adhere. Patterns such as lines or arrays were identified that could direct the growth of these subcellular neuronal processes. At higher hydrogel spacings, both neurons and astrocytes adhered and grew in a manner approaching that of unpatterned control surfaces. Patterned lines could once again direct growth at cellular length scales. Significantly, we have demonstrated that the patterning of sub-micron/nano scale cell-repulsive features at microscale lengths on an otherwise cell-adhesive surface can differently control the adhesion and growth of cells and cell processes based on the difference in their characteristic sizes. This concept could potentially be applied to an implantable nerve-guidance device that would selectively enable regrowing axons to bridge a spinal-cord injury without interference from the glial scar.

  4. Structural, optical and magnetic properties of Cr doped SnO{sub 2} nanoparticles stabilized with polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Subramanyam, K.; Sreelekha, N. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Murali, G. [Department of BIN Fusion Technology and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, Jeonbuk (Korea, Republic of); Reddy, D. Amaranatha [Department of Chemistry and Chemical Institute for Functional Materials, Pusan National University, Busan 609-735 (Korea, Republic of); Vijayalakshmi, R.P., E-mail: vijayaraguru@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India)

    2014-12-01

    Pure and Cr (1, 3, 5 and 7 at%) doped SnO{sub 2} nanoparticles were synthesized in aqueous solution by a simple chemical co-precipitation method using polyethylene glycol (PEG) as a stabilizing agent. The effect of Cr doping on the structural, optical and magnetic properties of SnO{sub 2} nanoparticles was investigated. EDAX spectra confirmed the presence of Sn, O and Cr in near stoichiometry. XRD patterns revealed that particles of all samples were crystallized in single phase rutile type tetragonal crystal structure (P4{sub 2}/mnm) of SnO{sub 2}. The peak positions with Cr concentration shifted to higher 2θ values. Lattice parameters were also decreased with increasing Cr concentration. TEM studies indicated that the particle size is in the range of 8–10 nm. The optical absorption studies indicated that the absorption edge shifted towards lower wavelengths with inclusion of Cr content. FTIR spectrum displays various bands that are due to fundamental overtones of PEG and O–Sn–O entities. Further it revealed that the undoped and as well as Cr doped SnO{sub 2} nanoparticles were capped by PEG. Magnetization measurements at room temperature revealed that all the doped samples were ferromagnetic in nature. Well defined strong room temperature ferromagnetic hysteresis loop was observed for 1% Cr doped SnO{sub 2} nanoparticles.

  5. Solution and film properties of sodium caseinate/glycerol and sodium caseinate/polyethylene glycol edible coating systems.

    Science.gov (United States)

    Siew, D C; Heilmann, C; Easteal, A J; Cooney, R P

    1999-08-01

    The aim of this study is to determine the effects of plasticizer hydrogen bonding capability and chain length on the molecular structure of sodium caseinate (NaCAS), in NaCAS/glycerol and NaCAS/polyethylene glycol 400 (PEG) systems. Both solution and film phases were investigated. Glycerol and PEG reduced the viscosity of aqueous NaCAS, with the latter having a greater effect. This was explained in terms of protein/plasticizer aggregate size and changes to the conformation of the caseinate chain. In the film phase, glycerol caused more pronounced changes to the film tensile strength compared with PEG. However, the effect of glycerol on film water vapor permeability was smaller. These observations are attributed to the differences in plasticizer size and hydrogen bonding strength that controls the protein-plasticizer and protein-protein interactions in the films. Glass transition calculations from the tensile strength data indicate that the distribution of bonding interactions is more homogeneous in NaCAS/PEG films than in NaCAS/glycerol films.

  6. Surface modification of stainless steel by grafting of poly(ethylene glycol) for reduction in protein adsorption.

    Science.gov (United States)

    Zhang, F; Kang, E T; Neoh, K G; Wang, P; Tan, K L

    2001-06-01

    The surface of stainless steel was first modified by the silane coupling agent (SCA), (3-mercaptopropyl)trimethoxysilane. The silanized stainless-steel surface (SCA-SS surface) was subsequently activated by argon plasma and then subjected to UV-induced graft polymerization of poly(ethylene glycol)methacrylate (PEGMA). The chemical structures and composition of the pristine, silane-treated, plasma-treated and PEGMA graft-polymerized stainless-steel coupon surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The graft polymerization of PEGMA onto the plasma-pretreated SCA-SS surface was studied with different argon plasma pretreatment time, macromonomer concentration, and UV graft polymerization time. In general, a brief plasma pretreatment, high PEGMA concentration, and long UV graft polymerization time readily resulted in a high graft concentration. The PEGMA graft-polymerized stainless-steel coupon (PEGMA-g-SCA-SS) with a high graft concentration, and thus a high PEG content, was found to be very effective in preventing bovine serum albumin and gamma-globulin adsorption.

  7. Improved cellular infiltration into nanofibrous electrospun cross-linked gelatin scaffolds templated with micrometer-sized polyethylene glycol fibers

    Energy Technology Data Exchange (ETDEWEB)

    Skotak, Maciej [Biomechanics, Biomaterials and Biomedicine Instrumentation Facility, College of Engineering, University of Nebraska-Lincoln, NE 68588-0642 (United States); Ragusa, Jorge; Gonzalez, Daniela; Subramanian, Anuradha, E-mail: asubramanian2@unl.edu [Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE 68588-0643 (United States)

    2011-10-15

    Gelatin-based nanofibrous scaffolds with a mean fiber diameter of 300 nm were prepared with and without micrometer-sized polyethylene glycol (PEG) fibers that served as sacrificial templates. Upon fabrication of the scaffolds via electrospinning, the gelatin fibers were crosslinked with glutaraldehyde, and the PEG templates were removed using tert-butanol to yield nanofibrous scaffolds with pore diameters ranging from 10 to 100 {mu}m, as estimated with mercury intrusion porosimetry. Non-templated gelatin-based nanofibrous matrices had an average pore size of 1 {mu}m. Fibroblasts were seeded onto both types of the gelatin-based nanofibrous surfaces and cultured for 14 days. For comparative purposes, chitosan-based and polyurethane-based macroporous scaffolds with pore sizes of 100 and 170 {mu}m, respectively, were also included. The number of cells as a function of the depth into the scaffold was judged and quantitatively assessed using nuclei staining. Cell penetration up to a depth of 250 and 90 {mu}m was noted in gelatin scaffolds prepared with sacrificial templates and gelatin-only nanofibrous scaffolds. Noticeably, scaffold preparation protocol presented here allowed the structural integrity to be maintained even with high template content (95%) and can easily be extended toward other classes of electrospun polymer matrices for tissue engineering.

  8. Preparation and Characterization of Copolymer Micelles Formed by Poly(ethylene glycol)-Polylactide Block Copolymers as Novel Drug Carriers

    Institute of Scientific and Technical Information of China (English)

    姜维; 王运东; 甘泉; 张建铮; 赵秀文; 费维扬; 贝建中; 王身国

    2006-01-01

    Diblock copolymer poly(ethylene glycol) methyl ether-polylactide (MePEG-PLA) micelles were prepared by dialysis against water. Indomethacin (IMC) as a model drug was entrapped into the micelles by dialysis method. The critical micelle concentration (CMC) of the prepared micelles in distilled water investigated by fluorescence spectroscopy was 0.0051mg/mL which is lower than that of common low molecular weight surfactants. The diameters of MePEG-PLA micelles and IMC loaded MePEG-PLA micelles in a number-averaged scale measured by dynamic light scattering were 52.4 and 53.7 nm respectively. The observation with transmission electron microscope and scanning electron microscope showed that the appearance of MePEG-PLA micelles was in a spherical shape. The content of IMC incorporated in the core portion of the micelles was 18% (ω). The effects of the synthesis method of the copolymer on the polydispersity of the micelles and the yield of the micelles formation were discussed.

  9. Overcoming the polyethylene glycol dilemma via pathological environment-sensitive change of the surface property of nanoparticles for cellular entry.

    Science.gov (United States)

    Hama, Susumu; Itakura, Shoko; Nakai, Mayumi; Nakayama, Kayoko; Morimoto, Satoshi; Suzuki, Satoko; Kogure, Kentaro

    2015-05-28

    Modification with polyethylene glycol (PEG) is currently considered an important strategy for anti-cancer drug delivery, because PEGylated-nanoparticles would be effectively delivered to tumor tissue by enhanced permeation and retention effects. However, PEGylation suppresses the cellular uptake of nanoparticles (NPs) to target cells (known as the PEG dilemma). Here, we propose a novel strategy, namely conferring a pathological environment-sensitive property of nanoparticles for overcoming the PEG dilemma. Specifically, although nanoparticles have an overall negative surface charge to avoid interactions with biogenic substances in blood circulation, inversion of surface charge (to positive) at the pH of the tumor microenvironment may allow the nanoparticles to be taken up by cancer cells. To prove this concept, charge-invertible nanoparticles modified with novel slightly acidic pH-sensitive peptide (SAPSP-NPs) were developed. The negatively-charged SAPSP-NPs were delivered to tumor tissue, and were successfully taken up by cancer cells upon inversion of the surface charge to positive at intratumoral pH. SAPSP-NPs may serve as an alternative carrier to the PEGylated NP for anti-cancer drug delivery. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Isolation and characterization of a gene encoding a polyethylene glycol-induced cysteine protease in common wheat

    Indian Academy of Sciences (India)

    Qing-Wei Zang; Cai-Xiang Wang; Xu-Yan Li; Zhi-Ai Guo; Rui-Lian Jing; Jun Zhao; Xiao-Ping Chang

    2010-09-01

    Plant cysteine protease (CP) genes are induced by abiotic stresses such as drought, yet their functions remain largely unknown. We isolated the full-length cDNA encoding a Triticum aestivum CP gene, designated TaCP, from wheat by the rapid amplification of cDNA ends (RACE) method. Sequence analysis revealed that TaCP contains an open reading frame encoding a protein of 362 amino acids, which is 96% identical to barley cysteine protease HvSF42. The TaCP transcript level in wheat seedlings was upregulated during polyethylene glycol (PEG) stress, with a peak appearing around 12 h after treatment. TaCP expression level increased rapidly with NaCl treatment at 48 h. TaCP responded strongly to low temperature (4°C) treatment from 1 h post-treatment and reached a peak of about 40-fold at 72 h. However, it showed only a very slight response to abscisic acid (ABA). More than one copy of TaCP was present in each of the three genomes of hexaploid wheat and its diploid donors. TaCP fused with green fluorescent protein (GFP) was located in the plasma membrane of onion epidermis cells. Transgenic Arabidopsis plants overexpressing TaCP showed stronger drought tolerance and higher CP activity under water-stressed conditions than wild-type Arabidopsis plants. The results suggest that TaCP plays a role in tolerance to water deficit.

  11. FTIR and Raman Characterization of TiO2 Nanoparticles Coated with Polyethylene Glycol as Carrier for 2-Methoxyestradiol

    Directory of Open Access Journals (Sweden)

    Andrea León

    2017-01-01

    Full Text Available The aim of this study was to prepare a novel targeting drug delivery system for 2-Methoxyestradiol (2ME in order to improve the clinical application of this antitumor drug. It is based in nanoparticles (NPs of titanium dioxide (TiO2 coated with polyethylene glycol (PEG and loaded with 2ME. A complete IR and Raman characterization have been made to confirm the formation of TiO2–PEG–2ME composite. Vibrational modes have been assigned for TiO2, PEG, and 2ME and functionalized TiO2–PEG and TiO2–PEG–2ME. The observed variation in peak position of FTIR and Raman of each for these composites has been elucidated in terms of intermolecular interactions between PEG–2ME and TiO2, obtaining step-by-step the modification processes that were attributed to the conjugation of PEG and 2ME to TiO2 NPs. Modifying TiO2 NPs with PEG loaded with the 2ME drug revealed that the titanium dioxide nanocarrier possesses an effective adsorption capability, and we discuss their potential application as a system of drug delivery.

  12. Enhancing anticoagulation and endothelial cell proliferation of titanium surface by sequential immobilization of poly(ethylene glycol) and collagen

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chang-Jiang, E-mail: swjtupcj@163.com; Hou, Yan-Hua; Ding, Hong-Yan; Dong, Yun-Xiao

    2013-12-15

    In the present study, poly(ethylene glycol) (PEG) and collagen I were sequentially immobilized on the titanium surface to simultaneously improve the anticoagulation and endothelial cell proliferation. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy analysis confirmed that PEG and collagen I were successfully immobilized on the titanium surface. Water contact angle results suggested the excellent hydrophilic surface after the immobilization. The anticoagulation experiments demonstrated that the immobilized PEG and collagen I on the titanium surface could not only obviously prevent platelet adhesion and aggregation but also prolong activated partial thromboplastin time (APTT), leading to the improved blood compatibility. Furthermore, immobilization of collagen to the end of PEG chain did not abate the anticoagulation. As compared to those on the pristine and PEG-modified titanium surfaces, endothelial cells exhibited improved proliferative profiles on the surface modified by the sequential immobilization of PEG and collagen in terms of CCK-8 assay, implying that the modified titanium may promote endothelialization without abating the blood compatibility. Our method may be used to modify the surface of blood-contacting biomaterials such as titanium to promote endothelialization and improve the anticoagulation, it may be helpful for development of the biomedical devices such as coronary stents, where endothelializaton and excellent anticoagulation are required.

  13. Enhancing anticoagulation and endothelial cell proliferation of titanium surface by sequential immobilization of poly(ethylene glycol) and collagen

    Science.gov (United States)

    Pan, Chang-Jiang; Hou, Yan-Hua; Ding, Hong-Yan; Dong, Yun-Xiao

    2013-12-01

    In the present study, poly(ethylene glycol) (PEG) and collagen I were sequentially immobilized on the titanium surface to simultaneously improve the anticoagulation and endothelial cell proliferation. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy analysis confirmed that PEG and collagen I were successfully immobilized on the titanium surface. Water contact angle results suggested the excellent hydrophilic surface after the immobilization. The anticoagulation experiments demonstrated that the immobilized PEG and collagen I on the titanium surface could not only obviously prevent platelet adhesion and aggregation but also prolong activated partial thromboplastin time (APTT), leading to the improved blood compatibility. Furthermore, immobilization of collagen to the end of PEG chain did not abate the anticoagulation. As compared to those on the pristine and PEG-modified titanium surfaces, endothelial cells exhibited improved proliferative profiles on the surface modified by the sequential immobilization of PEG and collagen in terms of CCK-8 assay, implying that the modified titanium may promote endothelialization without abating the blood compatibility. Our method may be used to modify the surface of blood-contacting biomaterials such as titanium to promote endothelialization and improve the anticoagulation, it may be helpful for development of the biomedical devices such as coronary stents, where endothelializaton and excellent anticoagulation are required.

  14. Gold nanoparticles and polyethylene glycols functionalized conducting polyaniline nanowires for ultrasensitive and low fouling immunosensing of alpha-fetoprotein.

    Science.gov (United States)

    Hui, Ni; Sun, Xiaotian; Song, Zhiling; Niu, Shuyan; Luo, Xiliang

    2016-12-15

    An ultrasensitive biosensor for alpha-fetoprotein was developed based on electrochemically synthesized polyaniline (PANI) nanowires, which were functionalized with gold nanoparticles (AuNPs) and polyethylene glycols (PEG). The prepared PEG/AuNPs/PANI composite, combining the electrical conductivity of the AuNPs/PANI with the robust antifouling ability of PEG, offered an ideal substrate for the development of low fouling electrochemical biosensors. Alpha-fetoprotein (AFP), a well-known hepatocellular carcinoma biomarker, was used as a model analyte, and its antibody was immobilized on the PEG/AuNPs/PANI for the construction of the AFP immunosensor. Using the redox current of PANI as the sensing signal, in addition to the good biocompatibility of PEG/AuNPs and the anti-biofouling property of PEG, the developed immunosensor showed improved biosensing performances, such as wide linear range and ultralow detection limit (0.007pgmL(-1)). More importantly, it is label-free, reagentless and low fouling, making it capable of assaying AFP in real serum samples without suffering from significant interference or biofouling. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Immobilization of Quantum Dots in the Photo-Cross-Linked Poly(ethylene glycol)-Based Hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Gattas-Asfura, Kerim M.(Miami University); Zheng, Yujun (Miami University); Micic, Miodrag (BATTELLE (PACIFIC NW LAB)); Snedaker, Michael J.(Miami University); Ji, Xiaojun (Miami University); Sui, Guodong (Miami University); Orbulescu, Jhony (Miami University); Andreopoulos, Fotios M.(Miami University); Pham, Si M.(Miami University); Wang, Chong M.(BATTELLE (PACIFIC NW LAB))

    2003-09-25

    An inorganic/organic composite hybrid nano-system has been successfully synthesized in which nanocrystalline quantum dots (QDs) were effectively immobilized within a photo-cross-linked poly(ethylene glycol) hydrogel. Organometallic synthesis of CdTe and CdSe QDs was accomplished with a trioctylphosphine oxide (TOPO) cap. Replacing the TOPO cap with mercaptoacetic acid groups further yielded modified water-soluble nanocrystals. The immobilization of these functionalized CdTe and CdSe QDs within PEG hydrogel network has been shown to be effective through utilization of physical trapping. The CdTe and CdSe QDs had a particle diameter of 4.5 and 2.5-6.0 nm, respectively. The most efficiently trapped QDs had a size of 4.5 nm or larger. Particle size determination was derived from spectroscopic (absorption and photoluminescence) and high-resolution transmission electron microscopic techniques. These QD-immobilized gel systems demonstrated photoluminescence characteristics unique to semiconductor QD nanocrystals. The authors have envisioned the utilization of the unique photophysical properties of this material as a convenient signal transducer for in vivo biosensing. The most promising application of the described QD/PEG-NC hybrid system is in the fields of in vivo fluorescence microscopy and as a monitoring system for drug delivery and wound healing.

  16. Antibacterial and cell-adhesive polypeptide and poly(ethylene glycol) hydrogel as a potential scaffold for wound healing.

    Science.gov (United States)

    Song, Airong; Rane, Aboli A; Christman, Karen L

    2012-01-01

    The ideal wound-healing scaffold should provide the appropriate physical and mechanical properties to prevent secondary infection, as well as an excellent physiological environment to facilitate cell adhesion, proliferation and/or differentiation. Therefore, we developed a synthetic cell-adhesive polypeptide hydrogel with inherent antibacterial activity. A series of polypeptides, poly(Lys)(x)(Ala)(y) (x+y=100), with varied hydrophobicity via metal-free ring-opening polymerization of NCA-Lys(Boc) and NCA-Ala monomers (NCA=N-carboxylic anhydride) mediated by hexamethyldisilazane (HMDS) were synthesized. These polypeptides were cross-linked with 6-arm polyethylene glycol (PEG)-amide succinimidyl glutarate (ASG) (M(w)=10K) to form hydrogels with a gelation time of five minutes and a storage modulus (G') of 1400-3000 Pa as characterized by rheometry. The hydrogel formed by cross-linking of poly(Lys)(60)(Ala)(40) (5 wt.%) and 6-arm PEG-ASG (16 wt.%) (Gel-III) exhibited cell adhesion and cell proliferation activities superior to other polypeptide hydrogels. In addition, Gel-III displays significant antibacterial activity against Escherichia coli JM109 and Staphylococcus aureus ATCC25923. Thus, we have developed a novel, cell-adhesive hydrogel with inherent antibacterial activity as a potential scaffold for cutaneous wound healing.

  17. Kinetics of the esterification of active pharmaceutical ingredients containing carboxylic acid functionality in polyethylene glycol: formulation implications.

    Science.gov (United States)

    Schou-Pedersen, Anne Marie V; Hansen, Steen Honoré; Moesgaard, Birthe; Østergaard, Jesper

    2014-08-01

    Polyethylene glycols (PEGs) are attractive as excipients in the manufacture of drug products because they are water soluble and poorly immunogenic. They are used in various pharmaceutical preparations. However, because of their terminal hydroxyl groups, PEGs can participate in esterification reactions. In this study, kinetics of two active pharmaceutical ingredients, cetirizine and indomethacin possessing carboxylic acid functionality, has been studied in PEG 400 and PEG 1000 at 50 °C, 60 °C, 70 °C, and 80 °C. HPLC-UV was applied for the determination of concentrations in the kinetic studies, whereas HPLC-MS was used to identify reaction products. The esterification reactions were observed to be reversible. A second-order reversible kinetic model was applied and rate constants were determined. The rate constants demonstrated that cetirizine was esterified about 240 times faster than indomethacin at 80 °C. The shelf-life for cetirizine in a PEG 400 formulation at 25 °C expressed as t(95%) was predicted to be only 30 h. Further, rate constants for esterification of cetirizine in PEG 1000 in relation to PEG 400 decreased by a factor of 10, probably related to increased viscosity. However, it is important to be aware of this drug-excipient interaction, as it can reduce the shelf-life of a low-average molecular weight PEG formulation considerably.

  18. Surface chemistry and size influence the release of model therapeutic nanoparticles from poly(ethylene glycol) hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Hume, Stephanie L.; Jeerage, Kavita M., E-mail: jeerage@boulder.nist.gov [National Institute of Standards and Technology (NIST), Applied Chemicals and Materials Division, Material Measurement Laboratory (United States)

    2013-05-15

    Nanoparticles have emerged as promising therapeutic and diagnostic tools, due to their unique physicochemical properties. The specific core and surface chemistries, as well as nanoparticle size, play critical roles in particle transport and interaction with biological tissue. Localized delivery of therapeutics from hydrogels is well established, but these systems generally release molecules with hydrodynamic radii less than {approx}5 nm. Here, model nanoparticles with biologically relevant surface chemistries and diameters between 10 and 35 nm are analyzed for their release from well-characterized hydrogels. Functionalized gold nanoparticles or quantum dots were encapsulated in three-dimensional poly(ethylene glycol) hydrogels with varying mesh size. Nanoparticle size, surface chemistry, and hydrogel mesh size all influenced the release of particles from the hydrogel matrix. Size influenced nanoparticle release as expected, with larger particles releasing at a slower rate. However, citrate-stabilized gold nanoparticles were not released from hydrogels. Negatively charged carboxyl or positively charged amine-functionalized quantum dots were released from hydrogels at slower rates than neutrally charged PEGylated nanoparticles of similar size. Transmission electron microscopy images of gold nanoparticles embedded within hydrogel sections demonstrated uniform particle distribution and negligible aggregation, independent of surface chemistry. The nanoparticle-hydrogel interactions observed in this work will aid in the development of localized nanoparticle delivery systems.

  19. Ion-induced nucleation of dibutyl phthalate vapors on spherical and nonspherical singly and multiply charged polyethylene glycol ions.

    Science.gov (United States)

    Nasibulin, Albert G; de la Mora, Juan Fernandez; Kauppinen, Esko I

    2008-02-14

    Dibutyl phthalate vapor nucleation induced by positive polyethylene glycol (PEG) ions with controlled sizes and charges was experimentally studied. The ions were produced by electrospray ionization, classified in a high-resolution differential mobility analyzer, and studied in a nano condensation nucleus counter of the mixing type. Ionic radii of PEG varied from 0.52 to 1.56 nm, including from singly to quadruply charged ions. Some of these ions are fully stretched chains, other are spherical, and others have intermediate forms, all of them having been previously characterized by mobility and mass spectrometry studies. Activation of PEG1080(+2) requires a supersaturation almost as high as that required for small singly charged ions and higher than for PEG1080(+). This anomaly is explained by the Coulombic stretching of the ion into a long chain, where the two charged centers appear to be relatively decoupled from each other. The critical supersaturation for singly charged spherical ions falls below Thomson's (capillary) theory and even below the already low values seen previously for tetraheptyl ammonium bromide clusters. Spherical PEG4120(+2) falls close to the Thomson curve. The trends observed for slightly nonspherical PEG4120(+3) and highly nonspherical (but not quite linear) PEG4120(+4) are intermediate between those of multiply charged spheres and small singly charged ions.

  20. Effect of Polyethylene Glycol Modification of TiO2 Nanoparticles on Cytotoxicity and Gene Expressions in Human Cell Lines

    Directory of Open Access Journals (Sweden)

    Shuji Sonezaki

    2012-03-01

    Full Text Available Nanoparticles (NPs are tiny materials used in a wide range of industrial and medical applications. Titanium dioxide (TiO2 is a type of nanoparticle that is widely used in paints, pigments, and cosmetics; however, little is known about the impact of TiO2 on human health and the environment. Therefore, considerable research has focused on characterizing the potential toxicity of nanoparticles such as TiO2 and on understanding the mechanism of TiO2 NP-induced nanotoxicity through the evaluation of biomarkers. Uncoated TiO2 NPs tend to aggregate in aqueous media, and these aggregates decrease cell viability and induce expression of stress-related genes, such as those encoding interleukin-6 (IL-6 and heat shock protein 70B’ (HSP70B’, indicating that TiO2 NPs induce inflammatory and heat shock responses. In order to reduce their toxicity, we conjugated TiO2 NPs with polyethylene glycol (PEG to eliminate aggregation. Our findings indicate that modifying TiO2 NPs with PEG reduces their cytotoxicity and reduces the induction of stress-related genes. Our results also suggest that TiO2 NP-induced effects on cytotoxicity and gene expression vary depending upon the cell type and surface modification.