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Sample records for acid-g-ethylene glycol prepared

  1. Preparation and Separation of Telechelic Carborane-Containing Poly(ethylene glycol)s

    Matějíček, P.; Uchman, M.; Lepšík, Martin; Srnec, Martin; Zedník, J.; Kozlík, P.; Kalíková, K.

    2013-01-01

    Roč. 78, č. 6 (2013), s. 528-535. ISSN 2192-6506 R&D Projects: GA AV ČR IAAX00320901 Grant ostatní: GA ČR(CZ) GPP208/12/P236 Institutional support: RVO:61388963 Keywords : carboranes * click chemistry * poly(ethylene glycol) * quantum chemistry * reaction mechanisms Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.242, year: 2013

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

    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. PMID:27603372

  3. Preparation and Thermo-Physical Properties of Fe2O3-Propylene Glycol Nanofluids.

    Shylaja, A; Manikandan, S; Suganthi, K S; Rajan, K S

    2015-02-01

    Iron oxide (Fe2O3) nanoparticles were prepared from ferric chloride and ferrous sulphate by precipitation reaction. Fe2O3-propylene glycol nanofluid was prepared by dispersing Fe2O3 nanoparticles in propylene glycol through stirred bead milling, shear homogenization and probe ultrasonication. The nanofluid was characterized through measurement of viscosity, particle size distribution and thermal conductivity. The interactions between Fe2O3 nanoparticles and propylene glycol on the nanoparticle surfaces lead to reduction in viscosity, the magnitude of which increases with nanoparticle concentration (0-2 vol%) at room temperature. The thermal conductivity enhancement for 2 vol% nanofluid was about 21% at room temperature, with liquid layering being the major contributor for thermal conductivity enhancement. PMID:26353708

  4. Preparation of Ethylene Glycol Monoethyl Ether Acetate Using a Tubular Reactor

    蔡振云; 卢祖国; 李小波

    2003-01-01

    Ethylene glycol monoethyl ether acetate (EGEA), an excellent solvent, is prepared with ethylene oxide (EO) and ethyl acetate (EA) in a tubular reactor under suitable reaction condition. The single circulation yield can reach 81%. This technology is not only safe but also makes it possible to continuously produce EGEA in industry,with low content of high boiling point by-products.

  5. Electrochemical preparation of ether ketones from (poly)propylene glycol monoethers

    This invention is a method for preparing an ether ketone comprising electrolyzing a solution containing a (poly)propylene glycol monoether, hydroxyl ions and optionally water in an electrolytic cell having an anode at least partially coated with nickel peroxide, silver peroxide, cobalt peroxide or copper peroxide

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

    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.

  7. Preparation and evaluation of cosmetic patches containing lactic and glycolic acids

    Mahdavi H.; Kermani Z; Faghihi G; Asilian A; Hamishehkar H; Jamshidi A.

    2006-01-01

    Background: Alpha-hydroxy acids such as glycolic acid (GA) and lactic acid (LA), are used in cosmetic patches. The important fact in cosmetic patches is its suitable adhesion and peel properties. Aim: The objective of this study was to prepare LA- and GA-containing cosmetic patches and evaluate in-vitro/in-vivo correlation of adhesion properties. Methods: Pressure-sensitive adhesives with different concentrations of GA and LA were cast on a polyethylene terephthalate film. The patches we...

  8. Solvent free microwave assisted preparation of new telechelic polymers based on poly(ethylene glycol

    2009-07-01

    Full Text Available Poly(ethylene glycol bis (methylimidazolium chloride (PEGBMIM with average molecular weights of 600 and 1000 g/mol and poly(ethylene glycol bis (2-oxazoline (PEGBOX with average molecular weight of 600 g/mol have been prepared using microwave irradiation under solvent-free condition. The method described herein is a very good, safe, clean, economical and environmentally friendly alternative to the classical procedures. The resulted products have been characterized by common spectroscopic methods, such as FT-IR (Fourier transform infrared spectroscopy, 1H NMR (Nuclear magnetic resonance of proton and elemental analysis. Also, the effects of power levels and irradiation time on the yield of reactions and solubility of products have been studied.

  9. Smart poly(oligo(propylene glycol) methacrylate) hydrogel prepared by gamma radiation

    Suljovrujic, E., E-mail: edin@vinca.rs; Micic, M.

    2015-01-01

    that the hydrogels with propylene glycol pendant chains can be easily prepared by gamma radiation and have potential for different applications as smart and biocompatible polymers.

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

    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.

  11. Hydrogenolysis of Glycerol to Propylene Glycol on Nanosized Cu-Zn-Al Catalysts Prepared Using Microwave Process.

    Kim, Dong Won; Ha, Sang Ho; Moon, Myung Jun; Lim, Kwon Taek; Ryu, Young Bok; Lee, Sun Do; Lee, Man Sig; Hong, Seong-Soo

    2015-01-01

    Cu-Zn-Al catalysts were prepared using microwave-assisted process and co-precipitation methods. The prepared catalysts were characterized by XRD, BET, XPS and TPD of ammonia and their catalytic activity for the hydrogenolysis of glycerol to propylene glycol was also examined. The XRD patterns of Cu/Zn/Al mixed catalysts show CuO and ZnO crystalline phase regardless of preparation method. The highest glycerol hydrogenolysis conversion is obtained with the catalyst having a Cu/Zn/Al ratio of 2:2:1. Hydrogen pre-reduction of catalysts significantly enhanced both glycerol conversions and selectivity to propylene glycol. The glycerol conversion increased with an increase of reaction temperature. However, the selectivity to propylene glycol increased with an increase of temperature, and then declined to 30.5% at 523 K. PMID:26328420

  12. Practical preparation procedures for docetaxel-loaded nanoparticles using polylactic acid-co-glycolic acid

    Keum CG

    2011-10-01

    Full Text Available Chang-Gu Keum1*, Young-Wook Noh1*, Jong-Suep Baek1, Ji-Ho Lim1, Chan-Ju Hwang1, Young-Guk Na1, Sang-Chul Shin2, Cheong-Weon Cho11College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Gungdong, Yuseonggu, Daejeon, South Korea; 2College of Pharmacy, Chonnam National University, Yongbongdong, Buggu, Gwangju, South Korea *These authors contributed equally to this work Background: Nanoparticles fabricated from the biodegradable and biocompatible polymer, polylactic-co-glycolic acid (PLGA, are the most intensively investigated polymers for drug delivery systems. The objective of this study was to explore fully the development of a PLGA nanoparticle drug delivery system for alternative preparation of a commercial formulation. In our nanoparticle fabrication, our purpose was to compare various preparation parameters. Methods: Docetaxel-loaded PLGA nanoparticles were prepared by a single emulsion technique and solvent evaporation. The nanoparticles were characterized by various techniques, including scanning electron microscopy for surface morphology, dynamic light scattering for size and zeta potential, x-ray photoelectron spectroscopy for surface chemistry, and high-performance liquid chromatography for in vitro drug release kinetics. To obtain a smaller particle, 0.2% polyvinyl alcohol, 0.03% D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS, 2% Poloxamer 188, a five-minute sonication time, 130 W sonication power, evaporation with magnetic stirring, and centrifugation at 8000 rpm were selected. To increase encapsulation efficiency in the nanoparticles, certain factors were varied, ie, 2–5 minutes of sonication time, 70–130 W sonication power, and 5–25 mg drug loading. Results: A five-minute sonication time, 130 W sonication power, and a 10 mg drug loading amount were selected. Under these conditions, the nanoparticles reached over 90% encapsulation efficiency. Release kinetics showed that 20

  13. Aqueous preparation of polyethylene glycol/sulfonated graphene phase change composite with enhanced thermal performance

    Highlights: • We report an aqueous preparation technique of PEG/graphene phase change composite. • Hydrophilic sulfonated graphene (SG) nanosheets were synthesized. • Large increase in thermal conductivity is attained at low SG loading. • High latent heat is retained due to the low filler loading. • Affinity between SG and PEG contributes to the enhanced thermal performance. - Abstract: A polyethylene glycol (PEG)/sulfonated graphene (SG) phase change composite with enhanced thermal performance was prepared by solution processing in aqueous medium. It is remarkable that the addition of only 4 wt.% of SG to PEG could lead to a four times higher increase in thermal conductivity and a slight decrease in the phase change enthalpy, which is attributed to the formation of efficient thermal conductive network within the PEG matrix relevant to the excellent thermal property and unique 2-dimensional morphology of graphene as well as strong interface affinity between PEG matrix and SG nanosheets. The aqueous preparation technique is expected to pioneer a new way to prepare environment friendly organic phase change materials, and the production of PEG/SG composites is potentially scalable due to the facile fabricating process

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

    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. Activated carbon fibers/poly(lactic-co-glycolic) acid composite scaffolds: Preparation and characterizations

    The present work is a first trial to introduce activated carbon fibers (ACF) with high adsorption capacity into poly(lactic-co-glycolic) acid (PLGA), resulting in a novel kind of scaffolds for tissue engineering applications. ACF, prepared via high-temperature processing of carbon fibers, are considered to possess bioactivity and biocompatibility. The ACF/PLGA composite scaffolds are prepared by solvent casting/particulate leaching method. Increments in both pore quantity and quality over the surface of ACF as well as a robust combination between ACF and PLGA matrix are observed via scanning electron microscopy (SEM). The high adsorption capacity of ACF is confirmed by methylene blue solution absorbency test. The surfaces of ACF are affiliated with many hydrophilic groups and characterized by Fourier transform infrared spectroscopy. Furthermore, the SEM images show that cells possess a favorable spreading morphology on the ACF/PLGA scaffolds. Besides, vivo experiments are also carried out to evaluate the histocompatibility of the composite scaffolds. The results show that ACF have the potential to become one of the most promising materials in biological fields. - Highlights: • ACF with strong adsorption capacity and porous structure for enhanced surface area • The incorporation of ACF promoting the porosity of composite scaffolds • The composite scaffolds having no side effect on cell adhesion and proliferation • The composite scaffolds presenting good biocompatibility in vivo

  16. Activated carbon fibers/poly(lactic-co-glycolic) acid composite scaffolds: Preparation and characterizations

    Shi, Yanni [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Han, Hao [College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Bayer Material Science China Co., Ltd, Shanghai 200120 (China); Quan, Haiyu; Zang, Yongju; Wang, Ning; Ren, Guizhi [College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Xing, Melcolm [Department of Mechanical Engineering, Faculty of Engineering and Department of Biochemistry and Genetics, Faculty of Medicine P.I., Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba (Canada); Wu, Qilin, E-mail: wql@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China)

    2014-10-01

    The present work is a first trial to introduce activated carbon fibers (ACF) with high adsorption capacity into poly(lactic-co-glycolic) acid (PLGA), resulting in a novel kind of scaffolds for tissue engineering applications. ACF, prepared via high-temperature processing of carbon fibers, are considered to possess bioactivity and biocompatibility. The ACF/PLGA composite scaffolds are prepared by solvent casting/particulate leaching method. Increments in both pore quantity and quality over the surface of ACF as well as a robust combination between ACF and PLGA matrix are observed via scanning electron microscopy (SEM). The high adsorption capacity of ACF is confirmed by methylene blue solution absorbency test. The surfaces of ACF are affiliated with many hydrophilic groups and characterized by Fourier transform infrared spectroscopy. Furthermore, the SEM images show that cells possess a favorable spreading morphology on the ACF/PLGA scaffolds. Besides, vivo experiments are also carried out to evaluate the histocompatibility of the composite scaffolds. The results show that ACF have the potential to become one of the most promising materials in biological fields. - Highlights: • ACF with strong adsorption capacity and porous structure for enhanced surface area • The incorporation of ACF promoting the porosity of composite scaffolds • The composite scaffolds having no side effect on cell adhesion and proliferation • The composite scaffolds presenting good biocompatibility in vivo.

  17. Preparation and performance of porous phase change polyethylene glycol/polyurethane membrane

    Based on the theory of clotty porous phase change materials, the porous membrane was prepared with the blend of polyurethane (PU) and two polyethylene glycol (PEG) systems. Studied by scanning electron microscope (SEM), Fourier transform infrared (FT-IR), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and thermo-gravimetric (TG) tests, the morphology structure, chemical composition, crystalline morphology, phase change behaviors and thermal stability of porous phase change membrane were investigated. The results showed that the PU/PEG membrane had obvious porous structural feature, suitable transition temperature and high transition enthalpy. It is a flexible membrane with good energy storage function. When it is between solid and liquid transfer state in microcosms, the membrane can still keep solid shape in macroscopic state at high temperature during phase transition processing. It means that porous membrane PCM can be regarded as functional polymer. This method solved the problem of low working materials content in phase change textile. It succeeded in introducing the porous technology into functional textile's formation, and developed a new way to improve the phase change enthalpy largely for adjustable textile.

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

    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

  19. Liraglutide-loaded poly(lactic-co-glycolic acid) microspheres: Preparation and in vivo evaluation.

    Wu, Junzi; Williams, Gareth R; Branford-White, Christopher; Li, Heyu; Li, Yan; Zhu, Li-Min

    2016-09-20

    In this work, we sought to generate sustained-release injectable microspheres loaded with the GLP-1 analogue liraglutide. Using water-in-oil-in-water double emulsion methods, poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with liraglutide were prepared. The microspheres gave sustained drug release over 30days, with cumulative release of up to 90% reached in vitro. The microspheres were further studied in a rat model of diabetes, and their performance compared with a group given daily liraglutide injections. Reduced blood sugar levels were seen in the microsphere treatment groups, with the results being similar to those obtained with conventional injections between 10 and 25days after the commencement of treatment. After 5 and 30days of treatment, the microspheres seem a little slower to act than the injections. The pathology of the rats' spleen, heart, kidney and lungs was probed after the 30-day treatment period, and the results indicated that the microspheres were safe and had beneficial effects on the liver, reducing the occurrence of fatty deposits seen in untreated diabetic rats. Moreover, in terms of liver, renal and cardiac functions, and blood lipid and antioxidant levels, the microspheres were as effective as the injections. The expression of several proteases linked to the metabolism of aliphatic acids and homocysteine was promoted by the microsphere formulations. Inflammatory markers in the microsphere treatment groups were somewhat higher than the injection group, however. The liraglutide/PLGA microspheres prepared in this work are overall shown to be efficacious in a rat model of diabetes, and we thus believe they have strong potential for clinical use. PMID:27343696

  20. Prospective randomized comparison of oral sodium phosphate and polyethylene glycol lavage for colonoscopy preparation

    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 (

  1. Polyethylene Glycol Electrolyte Lavage Solution versus Colonic Hydrotherapy for Bowel Preparation before Colonoscopy: A Single Center, Randomized, and Controlled Study

    Yan Cao; Kai-Yuan Zhang; Jiao Li; Hao Lu; Wan-Ling Xie; Sheng-Tao Liao; Dong-Feng Chen; Deng-Feng Zeng; Chun-Hui Lan

    2014-01-01

    This single center, randomized, and controlled study aimed to compare the effectiveness and safety of polyethylene glycol electrolyte lavage (PEG-EL) solution and colonic hydrotherapy (CHT) for bowel preparation before colonoscopy. A total of 196 eligible outpatients scheduled for diagnostic colonoscopy were randomly assigned to the PEG-EL (n = 102) or CHT (n = 94) groups. Primary outcome measures included colonic cleanliness and adverse effects. Secondary outcome measures were patient satisf...

  2. Preparation and evaluation of cosmetic patches containing lactic and glycolic acids

    Mahdavi H

    2006-01-01

    Full Text Available Background: Alpha-hydroxy acids such as glycolic acid (GA and lactic acid (LA, are used in cosmetic patches. The important fact in cosmetic patches is its suitable adhesion and peel properties. Aim: The objective of this study was to prepare LA- and GA-containing cosmetic patches and evaluate in-vitro/in-vivo correlation of adhesion properties. Methods: Pressure-sensitive adhesives with different concentrations of GA and LA were cast on a polyethylene terephthalate film. The patches were evaluated for peel adhesive strength. On the basis of in vitro adhesion properties the patches were selected for wear performance tests and skin irritation potential. Results: The adhesion properties (adhesion to steel plate and skin and cohesive strength tests indicated the substantial influence of GA and LA concentrations. Based on in vitro adhesion studies the patches containing 3% (w/w GA were selected for in vivo studies. In vivo studies show that a formulation containing 3% GA displays good adhesion on the skin, but it leaves little residues on the skin. Skin Irritation studies on healthy human volunteers showed negligible erythema at the site of application after 48h. Conclusion: The noninvasive patch test model was found useful for detecting irritant skin reactions to the cosmetic patch containing GA. Our results demonstrated a strong correlation between the adhesion to steel plate and adhesion to skin. But a weak correlation between the degree of adhesive residue on the skin in in vitro and in vivo tests was observed for the formulation containing 3% (w/w GA.

  3. Preparation of polystyrene-poly(ethylene glycol) diblock copolymer by "living" free radical polymerization

    Chen, Xianyi; Gao, Bo; Kops, Jørgen;

    1998-01-01

    Amphiphilic diblock copolymer containing segments of polystyrene and monomethoxypoly(ethylene glycol) (PS-b-PEG) was synthesised by a novel method. Initially, the adduct (BZ-TEMPO) obtained by reacting benzoyl peroxide, styrene, and 2,2,6,6-tetramethyl-piperidinyl-1-oxy (TEMPO) was isolated...

  4. Preparation of diesel emulsion using auxiliary emulsifier mono ethylene glycol and utilization in a turbocharged diesel engine

    Highlights: • Mono-ethylene glycol was used as an auxiliary emulsifier. • Using mono ethylene glycol prolonged precipitation duration of emulsions. • With using E5 and E10 fuels engine torque averagely increased by 0.35% and 1.73% respectively. • It was found that specific fuel consumption of emulsions is lower than diesel. • Using E10 fuel reduced CO, NOx and soot emissions 44%, 47% and 5% respectively. - Abstract: Diesel engines are used widely as they have lower fuel consumption and higher thermal efficiency in transportation sector. However, the emitted high NOx, CO and soot emissions have led researchers to search different alternative fuels. At this point, diesel fuels emulsions help to reduce exhaust emissions. In this study, the effects of diesel fuel emulsions containing 5% (E5) and 10% (E10) water on engine performance an exhaust emissions has been investigated. Mono ethylene glycol was used as an auxiliary emulsifier in the preparation of the emulsion. Use of the mono ethylene glycol reduced the subsidence rate of the E5 and E10 about 34.5% and 47.1% respectively. The experiments were conducted at full load condition and at 2500, 3250 and 4000 rpm engine speeds. Engine torque and power increased according to diesel fuel between 2400 and 3600 engine speed range when emulsified fuels were used. But significant reductions were observed after that engine speed range. It was observed that the nitrogenoxide (NOx) emission reduced 5.42% and 11.01% with using E5 and E10 fuel respectively according to diesel fuel at 2500 rpm. Also the soot emissions reduced 12.39% and 22.97% with using E5 and E10

  5. PREPARATION AND PROPERTIES OF POLY (LACTIC ACID-CO-GLYCOL TEREPHTHALIC ACID) COPOLYESTER

    GAO Cuili; JI Quan; KONG Qingshan; XIA Yanzhi

    2006-01-01

    To obtain a kind of biodegradable polymer material with satisfactory properties, a new biodegradable copolyester poly(lactic acid-co-glycol terephthalate) (PETA), was synthesized from three monomers of lactic acid, glycol and terephthalic acid. The resulting copolyesters, PETA, were characterized by FT-IR, 1H-NMR, DSC, TGA and by the ways of weight loss rate to characterize their biodegradability. The findings in this work indicated that, the TmS and TdS of copolyesters PETA increased with increasing contents of the terephthalic acid units. From the biodegradation tests in natural soil, boiling water, acid buffer solution and alkali buffer solution, it was shown that the biodegradability of copolyesters PETA decreased with increasing contents of the terephthalic acid units.

  6. Comparison of Two Laxative Agents for Precolonoscopy Bowel Preparation: Sennoside Versus Standard Polyethylene Glycol Solution

    NAD?R, I??lay; KAÇAR, Sabite; ÇAKAL, Ba?ak; AKDO?AN, Meral; ÖZ?N, Yasemin Özderin

    2009-01-01

    This study was undertaken to compare the efficacy of standard 4-liters polyethylene glycol solution (PEG) and sennoside for bowel cleansing. Eighty patients having colonoscopy indication for any reason were voluntarily admitted in to the study. Patients were randomized to two groups to receive either PEG (30 patients) or sennoside (50 patients) for colon cleansing. Colonic cleansing of the patients was evaluated by Aranchick scoring scale according to educational levels. The perfect c...

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

    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. PMID:20659509

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

    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.

  9. A new polyethylene glycol fiber prepared by coating porous zinc electrodeposited onto silver for solid-phase microextraction of styrene

    Sungkaew, Sakchaibordee; Thammakhet, Chongdee [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Thavarungkul, Panote [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Kanatharana, Proespichaya, E-mail: proespichaya.K@psu.ac.th [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand)

    2010-04-01

    A new polyethylene glycol fiber was developed for solid-phase microextraction (SPME) of styrene by electrodepositing porous Zn film on Ag wire substrate followed by coating with polyethylene glycol sol-gel (Ag/Zn/PEG sol-gel fiber). The scanning electron micrographs of fibers surface revealed a highly porous structure. The extraction property of the developed fiber-to-styrene residue from polystyrene packaged food was investigated by headspace solid-phase microextraction (HS-SPME) and analyzed with a gas chromatograph coupled with flame ionization detection (GC-FID). The new Ag/Zn/PEG sol-gel fiber is simple to prepare, low cost, robust, has high thermal stability and long lifetime, up to 359 extractions. Repeatability of one fiber (n = 6) was in the range of 4.7-7.5% and fiber-to-fiber reproducibility (n = 4) for five concentration values were in the range 3.4-10%. This Ag/Zn/PEG sol-gel fiber was compared to two commercial SPME fibers, 75 {mu}m carboxen/polydimethylsiloxane (CAR/PDMS) and 100 {mu}m polydimethylsiloxane (PDMS). Under their optimum conditions, Ag/Zn/PEG sol-gel fiber showed the highest sensitivity and the lowest detection limit at 0.28 {+-} 0.01 ng mL{sup -1}.

  10. A new polyethylene glycol fiber prepared by coating porous zinc electrodeposited onto silver for solid-phase microextraction of styrene

    A new polyethylene glycol fiber was developed for solid-phase microextraction (SPME) of styrene by electrodepositing porous Zn film on Ag wire substrate followed by coating with polyethylene glycol sol-gel (Ag/Zn/PEG sol-gel fiber). The scanning electron micrographs of fibers surface revealed a highly porous structure. The extraction property of the developed fiber-to-styrene residue from polystyrene packaged food was investigated by headspace solid-phase microextraction (HS-SPME) and analyzed with a gas chromatograph coupled with flame ionization detection (GC-FID). The new Ag/Zn/PEG sol-gel fiber is simple to prepare, low cost, robust, has high thermal stability and long lifetime, up to 359 extractions. Repeatability of one fiber (n = 6) was in the range of 4.7-7.5% and fiber-to-fiber reproducibility (n = 4) for five concentration values were in the range 3.4-10%. This Ag/Zn/PEG sol-gel fiber was compared to two commercial SPME fibers, 75 μm carboxen/polydimethylsiloxane (CAR/PDMS) and 100 μm polydimethylsiloxane (PDMS). Under their optimum conditions, Ag/Zn/PEG sol-gel fiber showed the highest sensitivity and the lowest detection limit at 0.28 ± 0.01 ng mL-1.

  11. Preparation and Characterization of Nimodipine-loaded Methoxy Poly (ethylene glycol)-poly (lactic acid) Diblock Copolymer Nanoparticles

    ZHA Liu-sheng; LI Lan; ZHAO Hui-peng

    2006-01-01

    Amphiphilic diblock copolymers, methoxy poly (ethylene glycol)-poly(lactic acid) (MePEG-PLA), were synthesized from monomers of DL-lactide and methoxy poly (ethylene glycol) by a ring opening bulk polymerization in the presence of stannous octoate. Their chemical structure and physical properties were investigated using FTIR, NMR, GPC, and fluorescence spectroscopy. To estimate the feasibility as colloidal drug carrier, nimodipine (ND) was loaded into MePEG-PLA block copolymer nanoparticles by phaseseparation/dialysis method. The mean diameter and drug loading efficiency of ND-loaded MePEG-PLA copolymer nanoparticles depended on PLA/MePEG block composition of the copolymer and drug/polymer feed ratio in preparation. NMR study confirmed that nimodipine was entrapped into the hydrophobic inner core of MePEG-PLA copolymer nanoparticles and hydrophilic PEG chains were located on the surface of the drug-loaded polymer nanoparticles. In vitro release experiments exhibited the sustained release behavior of nimodipine from MePEG-PLA copolymer nanoparticles, without any burst effect.

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

    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.

  13. Preparation of poly(polyethylene glycol methacrylate-co-acrylic acid) hydrogels by radiation and their physical properties

    The pH-responsive copolymer hydrogels were prepared with the monomers of polyethylene glycol methacrylate and acrylic acid based on γ-ray irradiation technique. The gel content of these copolymer hydrogels varied depending on both the composition of monomers and the radiation dose. Maximum gel percent and degree of crosslinking were obtained at the composition of equal amount of comonomers. These copolymer hydrogels did not show any noticeable change in swelling at lower pH range. However they showed an abrupt increase in swelling at higher pH range due to the ionization of carboxyl groups. This pH-responsive swelling behavior was applied for the insulin carrier via oral delivery. Insulin-loaded copolymer hydrogels released most of their insulin in the simulated intestinal fluid which had a pH of 6.8 but not in the simulated gastric fluid which had a pH of 1.2

  14. Preparation and characterization of diethylene glycol bis(2-aminophenyl) ether-modified glassy carbon electrode

    Diethylene glycol bis(2-aminophenyl) ether (DGAE) diazonium salt was covalently electrografted on a glassy carbon (GC) surface and behavior of this novel surface was investigated. Synthesis of DGAE diazonium salt (DGAE-DAS) and in situ modification of GC electrode were performed in aqueous media containing NaNO2, keeping the temperature below +4 deg. C. For the characterization of the modified electrode surface by cyclic voltammetry, dopamine (DA) was used to prove the attachment of the DGAE-DAS on the GC surface. Raman spectroscopy and electrochemical impedance spectroscopy (EIS) were used to observe the molecular bound properties of the adsorbates at the DGAE-modified GC surface (GC-DGAE). The EIS results were analyzed using the Randles equivalent circuit. The charge transfer resistance on bare GC and the modified surface were calculated using the model equivalent circuit for the ferrocene redox system. Surface coverage was found as 0.4 showing the presence of high pinhole and defects in the modified electrode. The rate constant of electron transfer through the monolayer was calculated for ferrocene. Working potential range and the stability of the DGAE-modified GC electrode was also determined

  15. Preparation of 5-Fluorouracii Loaded Polylactide-co-glycolide-co-methoxy Poly(ethylene glycol) (PLGA-mPEG) Nanoparticles via High Speed Shearing

    LIN Hang; REN Hui; WANG Xi-shan; TANG Qing-chao; TANG Jun; WANG Ce

    2008-01-01

    5-Fluorouracil(5-FU) loaded nanoparticles(NPs) were prepared by a high speed shearing double emulsion method with polylactide-co-glycolide-co-methoxy poly(ethylene glycol)(PLGA-mPEG) as loading material.The prepared NPs possess a negative zeta potential and their loading efficiency is about 15%(mass fraction).The result of in vitro release shows that the release behavior of 5-FU from NPs is coincident with Zero-level release from the second day.

  16. Bowel Preparation for Colonoscopy with Sodium Phosphate Solution versus Polyethylene Glycol-Based Lavage: A Multicenter Trial

    S. Schanz

    2008-01-01

    Full Text Available Background: Adequate bowel preparation is essential for accurate colonoscopy. Both oral sodium phosphate (NaP and polyethylene glycol-based lavage (PEG-ELS are used predominantly as bowel cleansing modalities. NaP has gained popularity due to low drinking volume and lower costs. The purpose of this randomized multicenter observer blinded study was to compare three groups of cleansing (NaP, NaP + sennosides, PEG-ELS + sennosides in reference to tolerability, acceptance, and cleanliness. Patient and Methods: 355 outpatients between 18 and 75 years were randomized into three groups (A, B, C receiving NaP = A, NaP, and sennosides = B or PEG-ELS and sennosides = C. Gastroenterologists performing colonoscopies were blinded to the type of preparation. All patients documented tolerance and adverse events. Vital signs, premedication, completeness, discomfort, and complications were recorded. A quality score (0–4 of cleanliness was generated. Results: The three groups were similar with regard to age, sex, BMI, indication for colonoscopy, and comorbidity. Drinking volumes (L (A = 4.33 + 1.2, B = 4.56 + 1.18, C = 4.93 + 1.71 were in favor of NaP (P = .005. Discomfort from ingested fluid was recorded in A = 39.8% (versus C: P = .015, B = 46.6% (versus C: P = .147, and C = 54.6%. Differences in tolerability and acceptance between the three groups were statistically not significant. No differences in adverse events and the cleanliness effects occurred in the three groups (P = .113. The cleanliness quality scores 0–2 were calculated in A: 77.7%, B: 86.7%, and C: 85.2%. Conclusions: These data fail to demonstrate significant differences in tolerability, acceptance, and preparation quality between the three types of bowel preparation for colonoscopy. Cleansing with NaP was not superior to PEG-ELS.

  17. Honeycomb-patterned films of polystyrene/poly(ethylene glycol):Preparation,surface aggregation and protein adsorption

    WAN LingShu; KE BeiBei; LI XiaoKai; MENG XiangLin; ZHANG LuYao; XU ZhiKang

    2009-01-01

    Highly ordered honeycomb-patterned polystyrene (PS)/poly(ethylene glycol) (PEG) films were prepared by a water-assisted method using an improved setup,which facilitated the formation of films with higher regularity,better reproducibility,and larger area of honeycomb structures.Surface aggregation of hydrophilic PEG and adsorption of bovine serum albumin (BSA) on the honeycomb-patterned films were investigated.Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used to observe the surface morphologies of the films before and after being rinsed with water.As confirmed by the FESEM images and the AFM phase images,PEG was enriched in the pores and could be gradually removed by water.The adsorption of fluorescence-labeled BSA on the films was studied in visual form using laser scanning confocal microscopy.Results clearly demonstrated that the protein-resistant PEG was selectively enriched in the pores.This water-assisted method may be a latent tool to prepare honeycomb-patterned biofunctional surfaces.

  18. Polyethylene Glycol Electrolyte Lavage Solution versus Colonic Hydrotherapy for Bowel Preparation before Colonoscopy: A Single Center, Randomized, and Controlled Study

    Yan Cao

    2014-01-01

    Full Text Available This single center, randomized, and controlled study aimed to compare the effectiveness and safety of polyethylene glycol electrolyte lavage (PEG-EL solution and colonic hydrotherapy (CHT for bowel preparation before colonoscopy. A total of 196 eligible outpatients scheduled for diagnostic colonoscopy were randomly assigned to the PEG-EL (n=102 or CHT (n=94 groups. Primary outcome measures included colonic cleanliness and adverse effects. Secondary outcome measures were patient satisfaction and preference, colonoscopic findings, ileocecal arrival rate, examiner satisfaction, and cecal intubation time. The results show that PEG-EL group was associated with significantly better colonic cleanliness than CHT group, fewer adverse effects, and increased examiner satisfaction. However, the CHT group had higher patient satisfaction and higher diverticulosis detection rates. Moreover, the results showed the same ileocecal arrival rate and patient preference between the two groups (P>0.05. These findings indicate that PEG-EL is the preferred option in patients who followed the preparation instructions completely.

  19. Preparation and Characterization of Copolymer Micelles Formed by Poly(ethylene glycol)-Polylactide Block Copolymers as Novel Drug Carriers

    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.

  20. Preparation and Properties of Polysulfone-poly(ethylene glycol) graft copolymer membrane.

    Woo, Seung-Moon; Kim, Deuk-Ju; Nam, Sang-Yong

    2014-10-01

    In this study, Graft copolymers composed of PSf backbones and PEG side chains were synthesized to prepare gas separation membranes with enhancing permeability and selectivity on carbon dioxide separation. PSf-g-PEG copolymers were synthesized by two steps, chloromethylation and graft reactions. Grafted PEG segment of PSf was controlled by molecular weight of PEG. Thermal properties of prepared mebrane were studied by TGA and DSC. T(g) of the copolymers was decreased with increasing of molecular weight of PEG. Hydrophilicity of PSf-g-PEG copolymer membrane was measured using contact angle method, and PEG grafted polymers showed lower contact angles due to higher hydrophilicity. Gas permeation properties of CO2 and N2 gases through the membranes were measured using time-lag method. The permeability of CO2 was enhanced with PEG moiety contents and increasing of number of PEG segment. The selectivity of CO2/N2 was increased with introducing of PEG due to higher solubility with CO2 gas. PMID:25942870

  1. Design, preparation and characterization of novel poly-lactic-co-glycolic acid-hyaluronic acid implants containing triptorelin acetate

    Nersi Jafary Omid

    2014-01-01

    Full Text Available Hormones and their derivatives are widely used to treat different types of diseases such as prostate cancer which is treated by agonists of gonadotropin-releasing hormone. Triptoreline salts are the first therapeutics of this group launched into the market in the form of microparticles (microspheres. Implants, as one of attractive injectable dosage forms, have many advantages over multi-particulate systems. Some of these advantages are dose adjustability, drug absorption improvement, constant release profile, etc. In this research, a new composite of poly-lactic-co-glycolic acid and hyaluronic acid was designed and prepared in the form of implants containing triptorelin acetate for administration as an injection under the skin (subcutaneously in arm or thigh area. The manufactured implants characterized by Fourier transform infrared spectroscopy, thermas gravimetric analysis, X-ray diffraction and scanning electron microscopy to assess different aspects of structure and morphology. The drug release profile was assessed by high performance liquid chromatography. These characterizations confirmed that the newly designed drug delivery has a good stability during manufacturing process. The release pattern of the implant was also studied and revealed that the release of the model drug follows a zero-order and erosion mechanism. The compatibility between the components of the newly designed implants and the release profile of the delivery system make it a promising device for drug delivery.

  2. Methotrexate Nanoparticles Prepared with Codendrimer from Polyamidoamine (PAMAM) and Oligoethylene Glycols (OEG) Dendrons: Antitumor Efficacy in Vitro and in Vivo.

    Zhao, Yanna; Guo, Yifei; Li, Ran; Wang, Ting; Han, Meihua; Zhu, Chunyan; Wang, Xiangtao

    2016-01-01

    The novel methotrexate-loaded nanoparticles (MTX/PGD NPs) prepared with amphiphilic codendrimer PGD from polyamidoamine and oligothylene glycol dendrons were obtained via antisolvent precipitation method augmented by ultrasonication. Based on the excellent hydrophility of PGD, the drug-loaded nanoparticles could be investigated easily with the high drug-loading content (~85.2%, w/w). The MTX/PGD NPs possessed spherical morphology, nanoscaled particle size (approximately 182.4 nm), and narrow particle size distribution. Release of MTX from MTX/PGD NPs showed a sustained release manner and completed within 48 h. Hemolytic evaluation indicated MTX/PGD NPs presented good blood compatibility, and the cytotoxicity of nanoparticles against breast cancer cells in vitro, biodistribution in tumor tissue, and antitumor efficacy in vivo were enhanced significantly compared to MTX injection. According to the higher drug-loading content, enhanced antitumor efficacy, and appropriate particle size, MTX/PGD NPs as the drug delivery systems could have potential application for cancer chemotherapy in clinic. PMID:27388443

  3. Methotrexate Nanoparticles Prepared with Codendrimer from Polyamidoamine (PAMAM) and Oligoethylene Glycols (OEG) Dendrons: Antitumor Efficacy in Vitro and in Vivo

    Zhao, Yanna; Guo, Yifei; Li, Ran; Wang, Ting; Han, Meihua; Zhu, Chunyan; Wang, Xiangtao

    2016-07-01

    The novel methotrexate-loaded nanoparticles (MTX/PGD NPs) prepared with amphiphilic codendrimer PGD from polyamidoamine and oligothylene glycol dendrons were obtained via antisolvent precipitation method augmented by ultrasonication. Based on the excellent hydrophility of PGD, the drug-loaded nanoparticles could be investigated easily with the high drug-loading content (~85.2%, w/w). The MTX/PGD NPs possessed spherical morphology, nanoscaled particle size (approximately 182.4 nm), and narrow particle size distribution. Release of MTX from MTX/PGD NPs showed a sustained release manner and completed within 48 h. Hemolytic evaluation indicated MTX/PGD NPs presented good blood compatibility, and the cytotoxicity of nanoparticles against breast cancer cells in vitro, biodistribution in tumor tissue, and antitumor efficacy in vivo were enhanced significantly compared to MTX injection. According to the higher drug-loading content, enhanced antitumor efficacy, and appropriate particle size, MTX/PGD NPs as the drug delivery systems could have potential application for cancer chemotherapy in clinic.

  4. Preparation of Cylinder-Shaped Porous Sponges of Poly(L-lactic acid), Poly(DL-lactic-co-glycolic acid), and Poly(ε-caprolactone)

    2014-01-01

    Design of mechanical skeletons of biodegradable synthetic polymers such as poly(L-lactic acid) (PLLA), poly(DL-lactic-co-glycolic acid) (PLGA), and poly( ε -caprolactone) (PCL) is important in the construction of the hybrid scaffolds of biodegradable synthetic polymers and naturally derived polymers such as collagen. In this study, cylinder-shaped PLLA, PLGA, and PCL sponges were prepared by the porogen leaching method using a cylinder model. The effects of polymer type, polymer fraction, cyl...

  5. Photoclick Hydrogels Prepared from Functionalized Cyclodextrin and Poly(ethylene glycol) for Drug Delivery and in Situ Cell Encapsulation.

    Shih, Han; Lin, Chien-Chi

    2015-07-13

    Polymers or hydrogels containing modified cyclodextrin (CD) are highly useful in drug delivery applications, as CD is a cytocompatible amphiphilic molecule that can complex with a variety of hydrophobic drugs. Here, we designed modular photoclick thiol-ene hydrogels from derivatives of βCD and poly(ethylene glycol) (PEG), including βCD-allylether (βCD-AE), βCD-thiol (βCD-SH), PEG-thiol (PEGSH), and PEG-norbornene (PEGNB). Two types of CD-PEG hybrid hydrogels were prepared using radical-mediated thiol-ene photoclick reactions. Specifically, thiol-allylether hydrogels were formed by reacting multiarm PEGSH and βCD-AE, and thiol-norbornene hydrogels were formed by cross-linking βCD-SH and multiarm PEGNB. We characterized the properties of these two types of thiol-ene hydrogels, including gelation kinetics, gel fractions, hydrolytic stability, and cytocompatibility. Compared with thiol-allylether hydrogels, thiol-norbornene photoclick reaction formed hydrogels with faster gelation kinetics at equivalent macromer contents. Using curcumin, an anti-inflammatory and anticancer hydrophobic molecule, we demonstrated that CD-cross-linked PEG-based hydrogels, when compared with pure PEG-based hydrogels, afforded higher drug loading efficiency and prolonged delivery in vitro. Cytocompatibility of these CD-cross-linked hydrogels were evaluated by in situ encapsulation of radical sensitive pancreatic MIN6 β-cells. All formulations and cross-linking conditions tested were cytocompatible for cell encapsulation. Furthermore, hydrogels cross-linked by βCD-SH showed enhanced cell proliferation and insulin secretion as compared to gels cross-linked by either dithiothreitol (DTT) or βCD-AE, suggesting the profound impact of both macromer compositions and gelation chemistry on cell fate in chemically cross-linked hydrogels. PMID:25996903

  6. Biocompatibility and drug release behavior of scaffolds prepared by coaxial electrospinning of poly(butylene succinate) and polyethylene glycol

    Llorens, E.; Ibañez, H. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Valle, L.J. del, E-mail: luis.javier.del.valle@upc.edu [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Center for Research in Nano-Engineering (CrNE), Universitat Politècnica de Catalunya, Edifici C, C/Pasqual i Vila s/n, Barcelona E-08028 (Spain)

    2015-04-01

    Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core–shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds. - Highlights: • Coaxial microfibers with different hydrophobicities were studied. • The surface morphology of the coaxial fiber shows the distribution of polymers. • Coaxial fiber microstructure favors the polymer molecular orientation. • These hybrid materials have greater advantages for loading and drug release. • PEG

  7. Biocompatibility and drug release behavior of scaffolds prepared by coaxial electrospinning of poly(butylene succinate) and polyethylene glycol

    Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core–shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds. - Highlights: • Coaxial microfibers with different hydrophobicities were studied. • The surface morphology of the coaxial fiber shows the distribution of polymers. • Coaxial fiber microstructure favors the polymer molecular orientation. • These hybrid materials have greater advantages for loading and drug release. • PEG

  8. Estudo comparativo entre manitol e polietilenoglicol no preparo intestinal para colonoscopia Manitol versus polyethylene glycol in bowel preparation for colonoscopy

    Marcelo Alexandre Pinto de Britto

    2009-06-01

    Full Text Available OBJETIVOS: O estudo visa comparar o preparo intestinal para colonoscopia com manitol a 10%, com o uso de polietilenoglicol (PEG. Levou-se em conta o custo de cada preparo, tolerabilidade, eficácia, e alterações bioquímicas causadas pela administração. MÉTODOS: Desenvolveu-se um ensaio clínico randomizado, duplo-cego, unicêntrico. Pacientes que já haviam feito o exame foram excluídos. Fez-se a dosagem de hematócrito, sódio, potássio e cloretos antes e depois do preparo. Escalas de sintomatologia e eficácia foram utilizadas. O custo foi calculado pelo volume médio necessário para obter-se evacuação com líquido claro sem resíduos. RESULTADOS: Foi necessário um litro a mais de solução de PEG para o preparo. Apesar disso, a tolerabilidade desta solução foi melhor. Na avaliação do colonoscopista sobre a qualidade do preparo, o manitol obteve vantagem. Não houveram alterações bioquímicas significativas, e o custo foi comparável. CONCLUSÃO: O manitol, apesar de parecer provocar mais sintomatologia nos pacientes, é mais eficaz na limpeza do cólon. Apesar de não ter seu uso endossado pelos últimos consensos internacionais, mostra-se seguro e eficaz. O PEG torna-se de custo vantajoso quando comprado pelo paciente, porém o manitol é mais barato em ambiente hospitalar.OBJECTIVES: The present study aims to analyze bowel preparation for colonoscopy with mannitol compared to polyethylene glycol (PEG. Variables were the cost of preparation, patient acceptance, efficacy, and biochemical imbalances due to the use. METHODS: A randomized, double-blind, unicentric clinical trial was designed. Patients already submitted to colonoscopies were excluded. Haematocrit, sodium, potassium, and chloride were evaluated before and after the administration. Symptom and efficacy scores were determined, and the cost was calculated by the average volume of solution necessary to produce a clear-liquid passage. RESULTS: It took one liter more

  9. Study of interaction of ethylene glycol/PVP phase on noble metal powders prepared by polyol process

    F Bonet; K Tekaia-Elhsissen; K Vijaya Sarathy

    2000-06-01

    Noble metal powders (Au, Ag, Pt, Pd and Ru) have been synthesized by the polyol process in both the nanometer and submicron scales (sans Pd, Pt and Ru). They have been characterized by both microscopic (TEM and SEM) as well as spectroscopic techniques (FT-IR and XPS). Infrared spectroscopy was employed to study the colloid particles in the presence of ethylene glycol and PVP and the results show that the interaction between the organic phase and the metal particles vary according to the particle size. The role of the solvent, ethylene glycol, during the reduction process was also investigated and we observe formation of >C=O vibration band after the reduction process implying that the solvent reduces the metal ions thereby getting oxidized. XPS measurements carried out on the colloidal sols have shown the presence of the organic phase adsorbed onto the metal particles.

  10. Preparation and properties of polyrotaxane from -cyclodextrin and poly(ethylene glycol) with poly(vinyl alcohol)

    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.

  11. Preparation of tissue engineering porous scaffold with poly(lactic acid) and polyethylene glycol solution blend by solvent-casting/particulate-leaching

    Polyethylene glycol/poly(lactic acid) solution blend is employed as the raw materials to prepare porous scaffold of potential usage in tissue engineering. The solution blend can be naturally introduced in the classical solvent casting/particular leaching technique in porous matrix preparation. The PEG presence is to modify the degradation behavior of scaffolds to fit particular requirements in tissue engineering. The porous matrix of PEG/PLA with various weight ratios are made with pores size ∼250 μm. The SEM characterizations have been done to investigate the porous morphology of products, the results indicate that though with the clear semi-miscibility feature of PEG/PLA blends, the macro-structure is not significantly affected by the PEG content percentage. The degradation results show an enhanced weight loss rate with the presence of PEG as expected. (paper)

  12. Preparation of poly(trimethyl-2-methacroyloxyethylammonium chloride-co-ethylene glycol dimethacrylate) monolith and its application in solid phase microextraction of brominated flame retardants.

    Yang, Ting-ting; Zhou, Lin-feng; Qiao, Jun-qin; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan

    2013-05-24

    A capillary poly(trimethyl-2-methacroyloxyethylammonium chloride-co-ethylene glycol dimethacrylate) monolith was in situ synthesized by thermally initiated free radical co-polymerization using trimethyl-2-methacroyloxyethylammonium chloride (MATE) and ethylene glycol dimethacrylate (EGDMA) as functional monomer and cross-linker, respectively. N,N-dimethylformamide and polyethylene glycol 6000 were used as solvent and porogen, respectively. The morphology and porous structure of the resulting monoliths were assessed by scanning electron microscope. In order to prepare practically useful poly(MATE-co-EGDMA) monoliths with low flow resistance and good mechanical strength, some parameters such as PEG-6000 to DMF ratio, total monomer to porogen ratio, and crosslinker to monomer ratio were optimized systematically. Moreover, the extraction mechanism was evaluated using two series of compounds, alkylbenzenes and weak acids, as model compounds on poly(MATE-co-EGDMA) monoliths as liquid chromatographic stationary phase. Finally, the monoliths were applied as the solid phase microextraction medium, and a simple off-line method for simultaneous determination of three brominated flame retardants, 2,4,6-tribromophenol (TBP), tetrabromobisphenol A (TBBPA) and 4,4'-dibrominated diphenyl ether (DBDPE), in environmental waters was developed by coupling the polymer monolith microextraction to HPLC with UV detection. The regression equations for these three brominated flame retardants showed good linearity from their limit of quantification to 5000ng/mL. The limits of detection were 0.20, 0.15 and 0.10ng/mL for TBP, TBBPA and DBDPE, respectively. The recovery of the proposed method was 78.7-106.1% with intra-day relative standard deviation of 1.3-4.4%. PMID:23602644

  13. Polyethylene glycol (PEG)-dendron phospholipids as innovative constructs for the preparation of super stealth liposomes for anticancer therapy.

    Pasut, Gianfranco; Paolino, Donatella; Celia, Christian; Mero, Anna; Joseph, Adrian Steve; Wolfram, Joy; Cosco, Donato; Schiavon, Oddone; Shen, Haifa; Fresta, Massimo

    2015-02-10

    Pegylation of nanoparticles has been widely implemented in the field of drug delivery to prevent macrophage clearance and increase drug accumulation at a target site. However, the shielding effect of polyethylene glycol (PEG) is usually incomplete and transient, due to loss of nanoparticle integrity upon systemic injection. Here, we have synthesized unique PEG-dendron-phospholipid constructs that form super stealth liposomes (SSLs). A β-glutamic acid dendron anchor was used to attach a PEG chain to several distearoyl phosphoethanolamine lipids, thereby differing from conventional stealth liposomes where a PEG chain is attached to a single phospholipid. This composition was shown to increase liposomal stability, prolong the circulation half-life, improve the biodistribution profile and enhance the anticancer potency of a drug payload (doxorubicin hydrochloride). PMID:25499917

  14. Preparation and Evaluation of Poly(Ethylene Glycol)-Poly(Lactide) Micelles as Nanocarriers for Oral Delivery of Cyclosporine A

    Zhang, Yanhui; Li, Xinru; Zhou, Yanxia; Wang, Xiaoning; Fan, Yating; Huang, Yanqing; Liu, Yan

    2010-06-01

    A series of monomethoxy poly(ethylene glycol)-poly(lactide) (mPEG-PLA) diblock copolymers were designed according to polymer-drug compatibility and synthesized, and mPEG-PLA micelle was fabricated and used as a nanocarrier for solubilization and oral delivery of Cyclosporine A (CyA). CyA was efficiently encapsulated into the micelles with nanoscaled diameter ranged from 60 to 96 nm with a narrow size distribution. The favorable stabilities of CyA-loaded polymeric micelles were observed in simulated gastric and intestinal fluids. The in vitro drug release investigation demonstrated that drug release was retarded by polymeric micelles. The enhanced intestinal absorption of CyA-loaded polymeric micelles, which was comparable to the commercial formulation of CyA (Sandimmun Neoral®), was found. These suggested that polymeric micelles might be an effective nanocarrier for solubilization of poorly soluble CyA and further improving oral absorption of the drug.

  15. Does Polyethylene Glycol (PEG) Plus Ascorbic Acid Induce More Mucosal Injuries than Split-Dose 4-L PEG during Bowel Preparation?

    Kim, Min Sung; Park, Jongha; Park, Jae hyun; Kim, Hyung Jun; Jang, Hyun Jeong; Joo, Hee Rin; Kim, Ji Yeon; Choi, Joon Hyuk; Heo, Nae Yun; Park, Seung Ha; Kim, Tae Oh; Yang, Sung Yeon

    2016-01-01

    Background/Aims The aims of this study were to compare the bowel-cleansing efficacy, patient affinity for the preparation solution, and mucosal injury between a split dose of poly-ethylene glycol (SD-PEG) and low-volume PEG plus ascorbic acid (LV-PEG+Asc) in outpatient scheduled colonoscopies. Methods Of the 319 patients, 160 were enrolled for SD-PEG, and 159 for LV-PEG+Asc. The bowel-cleansing efficacy was rated according to the Ottawa bowel preparation scale. Patient affinity for the preparation solution was assessed using a questionnaire. All mucosal injuries observed during colonoscopy were biopsied and histopathologically reviewed. Results There was no significant difference in bowel cleansing between the groups. The LV-PEG+Asc group reported better patient acceptance and preference. There were no significant differences in the incidence or characteristics of the mucosal injuries between the two groups. Conclusions Compared with SD-PEG, LV-PEG+Asc exhibited equivalent bowel-cleansing efficacy and resulted in improved patient acceptance and preference. There was no significant difference in mucosal injury between SD-PEG and LV-PEG+Asc. Thus, the LV-PEG+Asc preparation could be used more effectively and easily for routine colonoscopies without risking significant mucosal injury. PMID:26260754

  16. Preparation of poly(polyethylene glycol methacrylate-co-acrylic acid) hydrogels by radiation and their physical properties[Radiation; pH-responsive; Hydrogels; Insulin; Oral delivery

    Park, S.-E.; Nho, Y.-C. E-mail: ycnho@kaeri.re.kr; Kim, H.-I

    2004-02-01

    The pH-responsive copolymer hydrogels were prepared with the monomers of polyethylene glycol methacrylate and acrylic acid based on {gamma}-ray irradiation technique. The gel content of these copolymer hydrogels varied depending on both the composition of monomers and the radiation dose. Maximum gel percent and degree of crosslinking were obtained at the composition of equal amount of comonomers. These copolymer hydrogels did not show any noticeable change in swelling at lower pH range. However they showed an abrupt increase in swelling at higher pH range due to the ionization of carboxyl groups. This pH-responsive swelling behavior was applied for the insulin carrier via oral delivery. Insulin-loaded copolymer hydrogels released most of their insulin in the simulated intestinal fluid which had a pH of 6.8 but not in the simulated gastric fluid which had a pH of 1.2.

  17. Catalytic steam reforming of tar derived from steam gasification of sunflower stalk over ethylene glycol assisting prepared Ni/MCM-41

    Highlights: • Ni/MCM-41 was prepared by EG-assisted co-impregnation method. • EG-assisted co-impregnation method resulted in Ni particles well dispersed on MCM-41. • Ni/MCM-41-EG catalyst had high catalytic activity for tar reforming. • The highest H2 gas yield was obtained when using 20 wt.% Ni/MCM-41-EG. • The catalysts were reused up to 5 cycles without any serious deactivation. - Abstract: Ethylene glycol (EG) assisted impregnation of nickel catalyst on MCM-41 (Ni/MCM-41-EG) was performed and applied for steam reforming of tar derived from biomass. The catalyst was characterized by SEM–EDX, BET, XRD, and TPR. It is found that smaller nickel particles were well dispersed on MCM-41 and better catalytic activity was shown for the Ni/MCM-41-EG when compared with the catalyst of Ni/MCM-41 prepared by using the conventional impregnation method. H2 yield increased approximately 8% when using 20 wt.% Ni/MCM-41-EG instead of 20 wt.% Ni/MCM-41 for the steam reforming of tar derived from sunflower stalk. The catalyst reusability was also tested up to five cycles, and no obvious activity reduction was observed. It indicates that EG assisted impregnation method is a good way to prepare metal loaded porous catalyst with high catalytic activity, high loading amount and long-term stability for the tar reforming

  18. Preparation of silica-supported porous sorbent for heavy metal ions removal in wastewater treatment by organic-inorganic hybridization combined with sucrose and polyethylene glycol imprinting

    A new porous sorbent for wastewater treatment of metal ions was synthesized by covalent grafting of molecularly imprinted organic-inorganic hybrid on silica gel. With sucrose and polyethylene glycol 4000 (PEG 4000) being synergic imprinting molecules, covalent surface coating on silica gel was achieved by using polysaccharide-incorporated sol-gel process starting from the functional biopolymer, chitosan and an inorganic epoxy-precursor, gamma-glycidoxypropyltrimethoxysiloxane (GPTMS) at room temperature. The prepared porous sorbent was characterized by using simultaneous thermogravimetry and differential scanning calorimeter (TG/DSC), scanning electron microscopy (SEM), nitrogen adsorption porosimetry measurement and X-ray diffraction (XRD). Copper ion, Cu2+, was chosen as the model metal ion to evaluate the effectiveness of the new biosorbent in wastewater treatment. The influence of epoxy-siloxane dose, buffer pH and co-existed ions on Cu2+ adsorption was assessed through batch experiments. The imprinted composite sorbent offered a fast kinetics for the adsorption of Cu2+. The uptake capacity of the sorbent imprinted by two pore-building components was higher than those imprinted with only a single component. The dynamic adsorption in column underwent a good elimination of Cu2+ in treating electric plating wastewater. The prepared composite sorbent exhibited high reusability. Easy preparation of the described porous composite sorbent, absence of organic solvents, cost-effectiveness and high stability make this approach attractive in biosorption

  19. Preparation of complementary glycosylated hyperbranched polymer/poly(ethylene glycol) brushes and their selective interactions with hepatocytes.

    Liang, Su; Yu, Shan; Gao, Changyou

    2016-09-01

    Selective cell adhesion and migration, which mimics the natural biological events in vivo, is very important for the right repair of damaged tissues. In this study, glycosylated hyperbranched polymers (LA-HPMA) were synthesized, and were grafted on glass slide through dopamine deposition with different densities adjusted by co-grafting of poly(ethylene glycol) (PEG). The LA-HPMA and PEG molecular brushes were characterized by X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance with dissipation (QCM-d) and ellipsometry. The adhesion of human hepatoma (HepG2) cells was promoted on the surface of a higher LA-HPMA density, and the migration rate was accelerated from 6.4μm/h on PEG surface to 12.7μm/h on 75% LA-HPMA surface. By contrast, the density and spreading area of mouse embryonic fibroblast (NIH3T3) cells were not significantly influenced by the LA-HPMA density, and the migration rate did not change significantly on all types of surfaces either. Therefore, the specific interactions of carbohydrate-protein can be used to modulate cell behaviors in vitro, for example the selective adhesion and migration of HepG2 cells. PMID:27209383

  20. Platinum nanoparticles on carbon-nanotube support prepared by room-temperature reduction with H2 in ethylene glycol/water mixed solvent as catalysts for polymer electrolyte membrane fuel cells

    Zheng, Yuying; Dou, Zhengjie; Fang, Yanxiong; Li, Muwu; Wu, Xin; Zeng, Jianhuang; Hou, Zhaohui; Liao, Shijun

    2016-02-01

    Polyol approach is commonly used in synthesizing Pt nanoparticles in polymer electrolyte membrane fuel cells. However, the application of this process consumes a great deal of time and energy, as the reduction of precursors requires elevated temperatures and several hours. Moreover, the ethylene glycol and its oxidizing products bound to Pt are difficult to remove. In this work, we utilize the advantages of ethylene glycol and prepare Pt nanoparticles through a room-temperature hydrogen gas reduction in an ethylene glycol/water mixed solvent, which is followed by subsequent harvesting by carbon nanotubes as electrocatalysts. This method is simple, facile, and time-efficient, as the entire room-temperature reduction process is completed in a few minutes. As the solvent changes from water to an ethylene glycol/water mix, the size of Pt nanoparticles varies from 10 to 3 nm and their shape transitions from polyhedral to spherical. Pt nanoparticles prepared in a 1:1 volume ratio mixture of ethylene glycol/water are uniformly dispersed with an average size of ∼3 nm. The optimized carbon nanotube-supported Pt electrocatalyst exhibits excellent methanol oxidation and oxygen reduction activities. This work demonstrates the potential use of mixed solvents as an approach in materials synthesis.

  1. 用管式反应技术制备乙二醇乙醚乙酸酯%Preparation of Ethylene Glycol Monoethyl Ether Acetate Using a Tubular Reactor

    蔡振云; 卢祖国; 李小波

    2003-01-01

    Ethylene glycol monoethyl ether acetate (EGEA), an excellent solvent, is prepared with ethylene oxide(EO) and ethyl acetate (EA) in a tubular reactor under suitable reaction condition. The single circulation yield canreach 81%. This technology is not only safe but also makes it possible to continuously produce EGEA in industry,with low content of high boiling point by-products.

  2. Preparation of (Bi,Pb)2Sr2Ca2Cu3Ox precursor powders by a modified polyethylene glycol based sol-gel process

    Grivel, Jean-Claude; Andersen, N.H.

    2002-01-01

    A modified sol-gel process based on polyethylene glycol has been developed for preparing (Bi,Pb)(2)Sr2Ca2Cu3Ox precursor powders in view of Ag-sheeted tape manufacture. A careful control of the pH and concentration temperature yields an amorphous gel, which can be converted to a fine and extremely...

  3. Ethylene glycol assisted preparation of Ti(4+)-modified polydopamine coated magnetic particles with rough surface for capture of phosphorylated proteins.

    Ma, Xiangdong; Ding, Chun; Yao, Xin; Jia, Li

    2016-07-27

    The reversible protein phosphorylation is very important in regulating almost all aspects of cell life, while the enrichment of phosphorylated proteins still remains a technical challenge. In this work, polydopamine (PDA) modified magnetic particles with rough surface (rPDA@Fe3O4) were synthesized by introduction of ethylene glycol in aqueous solution. The PDA coating possessing a wealth of catechol hydroxyl groups could serve as an active medium to immobilize titanium ions through the metal-catechol chelation, which makes the fabrication of titanium ions modified rPDA@Fe3O4 particles (Ti(4+)-rPDA@Fe3O4) simple and very convenient. The spherical Ti(4+)-rPDA@Fe3O4 particles have a surface area of 37.7 m(2) g(-1) and superparamagnetism with a saturation magnetization value of 38.4 emu g(-1). The amount of Ti element in the particle was measured to be 3.93%. And the particles demonstrated good water dispersibility. The particles were used as adsorbents for capture of phosphorylated proteins and they demonstrated affinity and specificity for phosphorylated proteins due to the specific binding sites (Ti(4+)). Factors affecting the adsorption of phosphorylated proteins on Ti(4+)-rPDA@Fe3O4 particles were investigated. The adsorption capacity of Ti(4+)-rPDA@Fe3O4 particles for κ-casein was 1105.6 mg g(-1). Furthermore, the particles were successfully applied to isolate phosphorylated proteins in milk samples, which demonstrated that Ti(4+)-rPDA@Fe3O4 particles had potential application in selective separation of phosphorylated proteins. PMID:27251945

  4. Preparation, characterization, and in vivo study of rhein-loaded poly(lactic-co-glycolic acid nanoparticles for oral delivery

    Yuan Z

    2015-04-01

    Full Text Available Zheng Yuan, Xinhua GuDepartment of Gastrointestinal Surgery, Suzhou Municipal Hospital, Suzhou, People’s Republic of ChinaAbstract: A novel rhein formulation based on poly(lactic-co-glycolic acid (PLGA nanoparticles (NPs suitable for oral administration was developed in this study. The designed nanosystems were obtained by a modified spontaneous emulsification solvent diffusion method. The morphology of rhein-loaded PLGA NPs showed a spherical shape with a smooth surface, without any particle aggregation. Mean size of the NPs was 140.5±4.3 nm, and the zeta potential was -16.9±3.1 mV. The average drug loading was 3.9%±0.7%, and encapsulation efficiency was 84.5%±6.2%. Meanwhile, NPs are characterized by the slower release (only about 70% of rhein is released within 5 hours, and the model that fitted best for rhein released from the NPs was Higuchi kinetic model with correlation coefficient r=0.9993, revealing that rhein could be controlled released from the NPs. In vivo, NPs altered the distribution of rhein, and the half-life after oral administration was prolonged remarkably more than those of suspensions (22.6 hours vs 4.3 hours. The pharmacokinetic results indicated that the NPs had sustained-release efficacy. The area under the curve0–∞ of the NPs formulation was 3.07-fold higher than that of suspensions, suggesting that the encapsulated rhein had almost been absorbed in rats over the period of 12 hours. Although rhein-loaded PLGA NP formulations are hopefully used as a chemotherapeutic or adjuvant agent for human gastric cancer (SGC-7901, their in vivo antitumor effect and mechanisms at the molecular level still need further study.Keywords: rhein, PLGA, nanoparticles, release, pharmacokinetics, SGC-7901

  5. Preparation of a novel sorptive stir bar based on vinylpyrrolidone-ethylene glycol dimethacrylate monolithic polymer for the simultaneous extraction of diazepam and nordazepam from human plasma.

    Torabizadeh, Mahsa; Talebpour, Zahra; Adib, Nuoshin; Aboul-Enein, Hassan Y

    2016-04-01

    A new monolithic coating based on vinylpyrrolidone-ethylene glycol dimethacrylate polymer was introduced for stir bar sorptive extraction. The polymerization step was performed using different contents of monomer, cross-linker and porogenic solvent, and the best formulation was selected. The quality of the prepared vinylpyrrolidone-ethylene glycol dimethacrylate stir bars was satisfactory, demonstrating good repeatability within batch (relative standard deviation ultrasound-assisted liquid desorption, followed by high-performance liquid chromatography with ultraviolet detection for the simultaneous determination of diazepam and nordazepam in human plasma samples. To optimize the extraction step, a three-level, four-factor, three-block Box-Behnken design was applied. Under the optimum conditions, the analytical performance of the proposed method displayed excellent linear dynamic ranges for diazepam (36-1200 ng/mL) and nordazepam (25-1200 ng/mL), with correlation coefficients of 0.9986 and 0.9968 and detection limits of 12 and 10 ng/mL, respectively. The intra- and interday recovery ranged from 93 to 106%, and the relative standard deviations were less than 6%. Finally, the proposed method was successfully applied to the analysis of diazepam and nordazepam at their therapeutic levels in human plasma. The novelty of this study is the improved polarity of the stir bar coating and its application for the simultaneous extraction of diazepam and its active metabolite, nordazepam in human plasma sample. The method was more rapid than previously reported stir bar sorptive extraction techniques based on monolithic coatings, and exhibited lower detection limits in comparison with similar methods for the determination of diazepam and nordazepam in biological fluids. PMID:26840622

  6. Novel 4-Arm Poly(Ethylene Glycol-Block-Poly(Anhydride-Esters Amphiphilic Copolymer Micelles Loading Curcumin: Preparation, Characterization, and In Vitro Evaluation

    Li Lv

    2013-01-01

    Full Text Available A novel 4-arm poly(ethylene glycol-block-poly(anhydride-esters amphiphilic copolymer (4-arm PEG-b-PAE was synthesized by esterization of 4-arm poly(ethylene glycol and poly(anhydride-esters which was obtained by melt polycondensation of α-, ω-acetic anhydride terminated poly(L-lactic acid. The obtained 4-arm PEG-b-PAE was characterized by 1H-NMR and gel permeation chromatography. The critical micelle concentration of 4-arm PEG-b-PAE was 2.38 μg/mL. The curcumin-loaded 4-arm PEG-b-PAE micelles were prepared by a solid dispersion method and the drug loading content and encapsulation efficiency of the micelles were 7.0% and 85.2%, respectively. The curcumin-loaded micelles were spherical with a hydrodynamic diameter of 151.9 nm. Curcumin was encapsulated within 4-arm PEG-b-PAE micelles amorphously and released from the micelles, faster in pH 5.0 than pH 7.4, presenting one biphasic drug release pattern with rapid release at the initial stage and slow release later. The hemolysis rate of the curcumin-loaded 4-arm PEG-b-PAE micelles was 3.18%, which was below 5%. The IC50 value of the curcumin-loaded micelles against Hela cells was 10.21 μg/mL, lower than the one of free curcumin (25.90 μg/mL. The cellular uptake of the curcumin-loaded micelles in Hela cell increased in a time-dependent manner. The curcumin-loaded micelles could induce G2/M phase cell cycle arrest and apoptosis of Hela cells.

  7. Preparation and Bioactivity Properties of a Novel Composite Membrane of Fructose Mediated β-Tricalcium Pyrophosphate/(Polyethylene Glycol/Chitosan for Guided Tissue Regeneration

    Jian-Wen Wang

    2015-01-01

    Full Text Available A novel composite membrane of β-tricalcium pyrophosphate (β-TCP and fructose- (F- mediated chitosan/poly(ethylene glycol (CS/PEG was prepared by thermally induced phase separation technique. The prepared composite membranes were characterized using scanning electron microscopy (SEM and X-ray diffraction (XRD. The mechanical property, swelling, degradation, and cytotoxicity of the composite membranes were evaluated in vitro with respect to its potential for use as biodegradable guided tissue regeneration (GTR membrane. In vitro degradation tests showed the composite membrane with a controllable degradation rate when changing the β-TCP content. The incorporation of β-TCP granules also caused a significant enhancement of tensile strength. When β-TCP content is controlled to 50 wt%, homogeneous composite membranes with well mechanical property and enzymatic degradation rate can be obtained. Cytotoxicity assay demonstrates that the composite membranes were nontoxic and had very good cell compatibility. Most importantly, the release of calcium ions and glucosamine from the composite membranes was proved to increase the cell proliferation of NIH3T3. The results of this study have indicated that this novel F-β-TCP/CS/PEG composite can be a suitable material for GTR applications.

  8. In-situ preparation, characterization and anticorrosion property of polypropylene glycol/silver nanoparticles composite for mild steel corrosion in acid solution.

    Solomon, Moses M; Umoren, Saviour A

    2016-01-15

    A novel polypropylene glycol/silver nanoparticles (PPG/AgNPs) composite was prepared in-situ using natural honey as the reducing and capping agent. Characterization of the composite was done by UV-Vis spectroscopy, FTIR, TEM, XRD, and EDS. The TEM results reveal that the nanoparticles are spherical in shape. XRD and EDS results confirm the presence of elemental silver in the polymer matrix. The influence of the prepared composite on the corrosion inhibition of mild steel in 0.5M H2SO4 solution was studied by weight loss, electrochemical, SEM, EDS, and water contact angle measurements. Results show that PPG/AgNPs is effective inhibitor for mild steel in 0.5M H2SO4 solution and adsorbs onto the metal surface via chemisorption mechanism. Maximum inhibition efficiency of 94% is afforded by the highest studied concentration of PPG/AgNPs at 333K from weight loss measurements. Potentiodynamic polarization results reveal that the composite acts as a mixed-type corrosion inhibitor. Adsorption of PPG/AgNPs composite onto the mild steel surface follows Temkin adsorption isotherm. The SEM, EDS, and water contact angle images confirm the formation of PPG/AgNPs protective film on the mild steel surface. PMID:26433475

  9. Non-covalent nano-adducts of co-poly(ester amide) and poly(ethylene glycol): preparation, characterization and model drug-release studies.

    Legashvili, Irakli; Nepharidze, Nino; Katsarava, Ramaz; Sannigrahi, Biswajit; Khan, Ishrat M

    2007-01-01

    Biodegradable, biocompatible poly(ester amide)s (co-PEAs), composed of amino acids, fatty diols and carboxylic acids, have been synthesized. To improve the performance of co-PEAs in Federal Drug Administration-approved solvents such as water and ethanol, these polymers were complexed with poly(ethylene glycol) (PEG) of 10 kDa molecular mass have been prepared by solution blending. The non-covalent adducts were purified by precipitation into hexanes. Co-PEAs are soluble in organic solvents but are insoluble in water and ethanol; however, the co-PEA/PEG (0.8:1, w/w) adducts are soluble in ethanol and slightly soluble in water. 2D-NOESY NMR spectroscopy suggests that the non-covalent adducts are held together by multiple non-covalent interactions between the -CH2- groups of the two polymers (co-PEA and PEG). Differential scanning calorimetry studies indicate that the two polymers are interacting in the non-covalent adducts; the thermal properties of the adducts are different from those of the pure polymers. The solid-state adduct structures have been determined by atomic force microscopy (AFM). By one sample preparation method, nanoscale pancake-like structures were observed with an average diameter of 260 nm and an average height of 16 nm. Films of co-PEAs and (co-PEA)/PEG adducts containing Rhodamine B Base (RhBB), a model hydrophobic drug, were prepared. From the adduct/RhBB film containing 3% RhBB, 20% of the total RhBB was released within the first 2 h. Film and adduct composition may be varied to obtain different release profiles. The studies reported here demonstrate that non-covalent conjugation is a relatively easy and effective approach in developing new materials for application as biomaterials. PMID:17623550

  10. Polyethylene Glycol 3350

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

  11. Preparation of Hemocompatible Poly(lactic-co-glycolic acid)-F127 Nanospheres and Their Application to Biosensor for Analysis of Whole Blood.

    Sun, Chong; Niu, Yanlian; Yang, Xujie; Liu, Min; Yang, Xiaodi; Huang, Xiaohua; Zhao, Wenbo

    2015-01-01

    In this paper, the novel poly(lactic-co-glycolic acid)-F127 nanospheres (PLGA-F127 NSs) were synthesized and used to establish an amperometric glucose biosensor that can be applied in whole blood directly. This property of glucose biosensor was based on the antibiofouling property of PLGA-F127 NSs. More details of preparing PLGA-F127 NSs and immobilizing glucose oxidase (GOx) on (PLGA-F127)/glass carbon electrode (GCE) were presented. Then, the electrochemical behaviors of the biosensor in whole blood were studied. The cyclic voltammetric results indicated that GOx immobilized on PLGA-F127 NSs exhibited direct electron transfer reaction, which led to stable amperometric biosensing for glucose with a detection limit of 5.57 x 10(-6) M (S/N = 3). The glucose biosensor did not respond to ascorbic acid (AA) and uric.acid (UA) at their concentration normally encountered in blood. The development of materials science will bring significant input to high-performance biosensors relevant to diagnostics and therapy of interest for human health. PMID:26328311

  12. Preparation of polyethylene glycol acrylate as phase change material%丙烯酸聚乙二醇酯相变大单体的制备

    张鸿; 王倩倩; 相恒学; 王晓磊

    2011-01-01

    The polyethylene glycol acrylate(PEGA) as phase change material was synthesized via esterification with polyethylene glycol(PEG) 4000 and acryloyl chloride as raw material. The structure and properties of the PEGA were studied by means of infrared spectroscope (IR), polarized light microscope (PLM), differential scanning calorimetry (DSC) and thermogravimetry(TG). The optimum synthesis process of the PEGA was determined by orthogonal experiment. The characteristic absorption peaks of ester bond and ethylenic bond appear in the IR spectra of the PEGA. The PLM images indicate that there is obvious extinction cross section in the PEGA crystal but the crystal radius significantly decreases compared to pure PEG4000. The phase transition temperature of the PEGA is 46.53 X, and the crystallization enthalpy is 163.21 J/g according to the DSC analysis. The TG results demonstrate that the PEGA degrades at 230 t, showing its good heat resistance. A novel crosslinking network solid-solid phase change material can be prepared through curing of the PEGA.%以聚乙二醇(PEG)4000及丙烯酰氯为原料,采用酯化法合成了丙烯酸聚乙二醇酯(PEGA)相变大单体.利用红外光谱(IR)、偏光显微镜( PLM)、差示扫描量热(DSC)、热重(TG)分析等研究了PEGA相变大单体的结构与性能,通过正交实验获得PEGA的最佳合成工艺.IR显示PEGA中出现酯键及C=C的特征峰;PLM显示PEGA晶体仍有明显的结晶消光截面,但相对纯PEG4000而言,其晶体半径明显减小;DSC分析表明PEGA在46.53℃出现结晶峰,结晶焓为163.21 J/g;TG分析表明PEGA在230℃开始降解,耐热性较好.PEGA交联固化后可制得新型交联网络型固-固相变材料.

  13. Preparation and characterization of polylactide/poly(ε-caprolactone-poly(ethylene glycol-poly(ε-caprolactone hybrid fibers for potential application in bone tissue engineering

    Wang YL

    2014-04-01

    Full Text Available YueLong Wang,1,2,* Gang Guo,1,* HaiFeng Chen,2 Xiang Gao,1 RangRang Fan,1 DongMei Zhang,1 LiangXue Zhou2 1State Key Laboratory of Biotherapy and Cancer Center, 2Department of Neurosurgery, West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of China *These authors contributed equally to this paper Abstract: The aim of this study was to develop a kind of osteogenic biodegradable composite graft consisting of human placenta-derived mesenchymal stem cell (hPMSC material for site-specific repair of bone defects and attenuation of clinical symptoms. The novel nano- to micro-structured biodegradable hybrid fibers were prepared by electrospinning. The characteristics of the hybrid membranes were investigated by a range of methods, including Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry. Morphological study with scanning electron microscopy showed that the average fiber diameter and the number of nanoscale pores on each individual fiber surface decreased with increasing concentration of poly(ε-caprolactone-poly(ethylene glycol-poly(ε-caprolactone (PCEC. The prepared polylactide (PLA/PCEC fibrous membranes favored hPMSC attachment and proliferation by providing an interconnected, porous, three-dimensional mimicked extracellular environment. What is more, hPMSCs cultured on the electrospun hybrid PLA/PCEC fibrous scaffolds could be effectively differentiated into bone-associated cells by positive alizarin red staining. Given the good cellular response and excellent osteogenic potential in vitro, the electrospun PLA/PCEC fibrous scaffolds could be one of the most promising candidates for bone tissue engineering. Keywords: electrospinning, PLA, PCEC, hPMSCs, bone tissue engineering

  14. Preparation and characterization of chitosan-Polyethylene glycol-polyvinylpyrrolidone-coated superparamagnetic iron oxide nanoparticles as carrier system: Drug loading and in vitro drug release study.

    Prabha, G; Raj, V

    2016-05-01

    In the present research work, the anticancer drug "curcumin" is loaded with Chitosan (CS)-polyethylene glycol (PEG)-polyvinylpyrrolidone (PVP) (CS-PEG-PVP) polymer nanocomposites coated with superparamagnetic iron oxide (Fe3 O4 ) nanoparticles. The system can be used for targeted and controlled drug delivery of anticancer drugs with reduced side effects and greater efficiency. The prepared nanoparticles were characterized by Fourier transmission infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Curcumin drug-loaded Fe3 O4 -CS, Fe3 O4 -CS- PEG and Fe3 O4 -CS-PEG-PVP nanoparticles exhibited the mean particle size in the range of 183 - 390 nm with a zeta potential value of 26 mV-41 mV as measured using Malvern Zetasizer. The encapsulation efficiency, loading capacity and in-vitro drug release behaviour of curcumin drug-loaded Fe3 O4 -CS, Fe3 O4 -CS-PEG, and Fe3 O4 -CS-PEG-PVP nanoparticles were studied using UV spectrophotometer. Besides, the cytotoxicity of the prepared nanoparticles using MTT assay was also studied. The curcumin drug release was examined at different pH medium (4.5 and 7.4) and temperature (37°C and 45°C), and it was proved that the drug release depends upon the pH medium and temperature in addition to the nature of matrix. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 808-816, 2016. PMID:26996397

  15. Preparation and characterization of paclitaxel-loaded poly lactic acid-co-glycolic acid coating tracheal stent

    Kong Yingying; Zhang Jie; Wang Ting; Qiu Xiaojian; Wang Yuling

    2014-01-01

    Background In-stent restenosis caused by airway granulation poses a challenge due to the high incidence of recurrence after treatment.Weekly applications of anti-proliferative drugs have potential value in delaying the recurrence of airway obstruction.However,it is not practical to subject patients to repeated bronchoscopy and topical drug applications.We fabricated novel pacilitaxel-eluting tracheal stents with sustained and slow pacilitaxel release,which could inhibit the formation of granulation tissue.And we assessed the quality and drug release behaviors of drug-eluting stents (DESs) in vitro.Methods Stents were dipped vertically into a coating solution prepared by dissolving 0.5 g (2% w/v) of poly lactic acid-coglycolic acid (PLGA) and 0.025 g (0.1% w/v) of pacilitaxel in 25 ml of dichloromethane.DES morphology was examined by scanning electron microscopy (SEM).Pacilitaxel release kinetics from these DESs was investigated in vitro by shaking in PBS buffer followed by high performance liquid chromatography (HPLC).Results Using an orthogonal experimental design,we fabricated numerous pacilitaxel/PLGA eluting tracheal stents to assess optimum coating proportions.The optimum coating proportion was 0.1% (w/v) pacilitaxel and 2% (w/v) PLGA,which resulted in total pacilitaxel loading of (16.380 6±0.002 1) mg/stent.By SEM the coating was very smooth and uniform.Pacilitaxel released from DES was at (0.376 3±0.003 8) mg/d,which is a therapeutic level.There was a prolonged,sustained release of pacilitaxel of >40 days.Conclusions Paclitaxel-loaded PLGA coating tracheal stents were successfully developed and evaluated.Quality assessments demonstrated favorable surface morphology as well as sustained and effective drug release behavior,which provides an experimental reference for clinical practitioners.

  16. Preparation, characterization, and in vitro drug release behavior of glutathione-sensitive long-circulation micelles based on polyethylene glycol prodrug.

    Shi, Liyan; Ding, Kaikai; Sun, Xin; Zhang, Ling; Zeng, Tian; Yin, Yihua; Zheng, Hua

    2016-04-01

    In this paper, a kind of glutathione-sensitive polymeric micelles was prepared through assembling in aqueous solution of an amphiphilic polymeric prodrug which was synthesized by linkage of 6-mercaptopurine (6-MP) and polyethylene glycol monomethyl ether using propiolic acid as a connecting arm. The glutathione (GSH)-sensitive strategy is based on a Michael addition-elimination reaction, that is the amphiphilic polymeric prodrug which contains α, β-unsaturated carbonyl group acts as a Michael acceptor to receive the attack of nucleophile - glutathione, and undergoes elimination reaction to release the original drug. Transmission electron microscope observation showed that the polymeric micelles (PMs) had a spherical-like morphology with a mean diameter of 28 ± 3.2 nm. The dynamic light scattering investigation data exhibited that the size and distribution changes of PMs are negligible after being placed for 15 days. In vitro drug release study indicated that only less than 13% of 6-MP was released from the micelles under GSH stimulation at micromolar level, while 34.5, 53.7, and 77.8% accumulative release rates were achieved under GSH stimulation at millimolar level (1, 2 and 10 mM), respectively. The cell inhibition rate of PM solution against HL-60 cells carried out by MTT method reached 85%. The cellular uptake and the intracellular drug release of PMs in HL-60 cells were observed through determining the intracellular 6-MP content by UV-vis spectrophotometer. In vitro macrophage uptake study showed a low phagocytosis rate, indicating the long-circulation ability of the PMs. PMID:26764973

  17. Cardiovascular effects of intravenous administration of propylene glycol and of oxytetracycline in propylene glycol in calves.

    Gross, D R; Kitzman, J V; Adams, H R

    1979-06-01

    Comparisons were made of the acute cardiovascular effects of oxytetracycline, oxytetracycline in propylene glycol, and propylene glycol alone given to conscious dairy calves. The calves were chronically instrumented with intravascular catheters and electromagnetic flowmeter transducers in and on the pulmonary and renal arteries. Injection (IV) of aqueous preparations of oxytetracycline produced no statistically significant (P greater than 0.05) cardiocirculatory changes in these calves. Oxytetracycline in propylene glycol and propylene glycol alone both produced transient (1 to 4 minute) periods of cardiovascular depression characterized by cardiac asystole, systemic hypotension, and decreased pulmonary and renal arterial blood flow. The two preparations, in equivalent doses and volumes, produced statistically similar hemodynamic changes in the calves. The data from this study support the conclusion that the monitored cardiovascular effects of the commercially available oxytetracycline in propylene glycol in the intact, awake calves were due to the solvent propylene glycol. This conclusion is consistent with reports of other injectable products containing the same solvent. PMID:475130

  18. Novel 4-Arm Poly(Ethylene Glycol)-Block-Poly(Anhydride-Esters) Amphiphilic Copolymer Micelles Loading Curcumin: Preparation, Characterization, and In Vitro Evaluation

    Li Lv; Yuanyuan Shen; Min Li; Xiaofen Xu; Mingna Li; Shengrong Guo; Shengtang Huang

    2013-01-01

    A novel 4-arm poly(ethylene glycol)-block-poly(anhydride-esters) amphiphilic copolymer (4-arm PEG-b-PAE) was synthesized by esterization of 4-arm poly(ethylene glycol) and poly(anhydride-esters) which was obtained by melt polycondensation of α -, ω -acetic anhydride terminated poly(L-lactic acid). The obtained 4-arm PEG-b-PAE was characterized by 1H-NMR and gel permeation chromatography. The critical micelle concentration of 4-arm PEG-b-PAE was 2.38  μ g/mL. The curcumin-loaded 4-arm PEG-b-PA...

  19. Polymeric Micelles for Delivery of Poorly Soluble Drugs: Preparation and Anticancer Activity In Vitro of Paclitaxel Incorporated into Mixed Micelles Based on Poly(ethylene Glycol)-Lipid Conjugate and Positively Charged Lipids

    Wang, Junping; MONGAYT, DIMITRY; Torchilin, Vladimir P.

    2005-01-01

    Paclitaxel-loaded mixed polymeric micelles consisting of poly(ethylene glycol)-distearoyl phosphoethanolamine conjugates (PEG-PE), solid triglycerides (ST), and cationic Lipofectin® lipids (LL) have been prepared. Micelles with the optimized composition (PEG-PE/ST/LL/paclitaxel = 12/12/2/1 by weight) had an average micelle size of about 100 nm, and zeta-potential of about 26 mV. Micelles were stable and did not release paclitaxel when stored at 4°C in the darkness (just 2.9% of paclitaxel hav...

  20. Preparation of an antitumor and antivirus agent: chemical modification of α-MMC and MAP30 from Momordica Charantia L. with covalent conjugation of polyethyelene glycol

    Meng Y

    2012-06-01

    Full Text Available Yao Meng,1,2 Shuangfeng Liu,1 Juan Li,3 Yanfa Meng,3 Xiaojun Zhao2,41School of Medical Laboratory Science, Chengdu Medical College, Chengdu, China; 2West China Hospital Laboratory of Nanomedicine and Institute for Nanobiomedical Technology and Membrane Biology, Sichuan University, Chengdu, China; 3Key Laboratory of Bio-resources and Eco-environment Ministry of Education/Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, China; 4Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USABackground: Alpha-momorcharin (α-MMC and momordica anti-HIV protein (MAP30 derived from Momordica charantia L. have been confirmed to possess antitumor and antivirus activities due to their RNA-N-glycosidase activity. However, strong immunogenicity and short plasma half-life limit their clinical application. To solve this problem, the two proteins were modified with (mPEG2-Lys-NHS (20 kDa.Methodology/principal findings: In this article, a novel purification strategy for the two main type I ribosome-inactivating proteins (RIPs, α-MMC and MAP30, was successfully developed for laboratory-scale preparation. Using this dramatic method, 200 mg of α-MMC and about 120 mg of MAP30 was obtained in only one purification process from 200 g of Momordica charantia seeds. The homogeneity and some other properties of the two proteins were assessed by gradient SDS-PAGE, electrospray ionization quadruple mass spectrometry, and N-terminal sequence analysis as well as Western blot. Two polyethylene glycol (PEGylated proteins were synthesized and purified. Homogeneous mono-, di-, or tri-PEGylated proteins were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry. The analysis of antitumor and antivirus activities indicated that the serial PEGylated RIPs preserved moderate activities on JAR choriocarcinoma cells and herpes simplex

  1. Effect of Water Content in Ethylene Glycol Solvent on the Size of ZnO Nanoparticles Prepared Using Microwave Solvothermal Synthesis

    Jacek Wojnarowicz

    2016-01-01

    Full Text Available Zinc oxide nanoparticles (ZnO NPs were obtained by the microwave solvothermal synthesis (MSS method. The precursor of the MSS reaction was a solution of hydrated zinc acetate in ethylene glycol with water addition. It was proved that by controlling the water concentration in the precursor it was possible to control the size of ZnO NPs in a programmed manner. The less the water content in the precursor, the smaller the size of ZnO NPs obtained. The obtained NPs with the average particle size ranging from 25 nm to 50 nm were characterised by homogeneous morphology and a narrow distribution of particle sizes. The following parameters of the obtained ZnO NPs were determined: pycnometric density, specific surface area, phase purity, chemical composition, lattice parameters, average particle size, and particle size distribution. The average size of ZnO NPs was determined using Scherrer’s formula, Nanopowder XRD Processor Demo web application, by converting the results of the specific surface area, and TEM tests using the dark field technique. ZnO morphology and structure were determined using scanning electron microscopy (SEM and transmission electron microscopy (TEM. The test performed by the X-ray powder diffraction (XRD confirmed that crystalline ZnO, pure in terms of phase, had been obtained.

  2. Polyethylene glycol-grafted polystyrene particles

    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

  3. Improved streptococcal grouping antisera containing polyethylene glycol.

    George, J R; Ashworth, H; Facklam, R R; Harrell, W K; Palmer, D F

    1981-01-01

    Antisera to streptococcal groups A through G containing 4% polyethylene glycol 6000 were prepared and evaluated. Seventy strains of homologous and heterologous beta- and non-beta-hemolytic streptococci were included in the evaluation. Homologous reactions were determined against extracts prepared by four extraction methods: hot hydrochloric acid (Lancefield) extraction, autoclave extraction, hot formamide extraction, and nitrous acid extraction. Enhancement of the precipitin reaction in the p...

  4. Polyethylene glycolated PAMAM dendrimers-Efavirenz conjugates

    Pyreddy, Suneela; Kumar, Pandurangan Dinesh; KUMAR, PALANIRAJAN VIJAYARAJ

    2014-01-01

    Aim: The preparation of novel PEGylated PAMAM (poly-amidoamine) dendrimers for delivery of anti-HIV drug Efavirenz is reported. Method and Materials: About 5.0 G PAMAM dendrimers are prepared by ethylene diamine core via Michael addition by divergent method. PEGylation is done by polyethylene glycol 600 using epichlorhydrin as linker. PEGylated 5.0 G PAMAM dendrimers loaded with Efavirenz (EFV) are evaluated for FTIR, DSC, SEM, drug release, and stability studies. Results and Conclusion: From...

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

    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

  6. Preparation of methoxyl poly(ethylene glycol) (MPEG)-coated carbonyl iron particles (CIPs) and their application in potassium dihydrogen phosphate (KDP) magnetorheological finishing (MRF)

    Ji, Fang; Xu, Min; Wang, Baorui; Wang, Chao; Li, Xiaoyuan; Zhang, Yunfei; Zhou, Ming; Huang, Wen; Wei, Qilong; Tang, Guangping; He, Jianguo

    2015-10-01

    KDP is a common type of optics that is extremely difficult to polish by the conventional route. MRF is a local polishing technology based on material removal via shearing with minimal normal load and sub-surface damage. In contrast to traditional emendation on an abrasive, the MPEG soft coating is designed and prepared to modify the CIP surface to achieve a hardness matched with that of KDP because CIP inevitably takes part in the material removal during finishing. Morphology and infrared spectra are explored to prove the existence of homogeneous coating, and the improvement of MPEG for the polishing quality is validated by the analysis of roughness, turning grooves, and stress. The synthesized MPEG-coated CIP (MPEG-CIP) is chemically and physically compatible with KDP, which can be removed after cleaning. Our research exhibits the promising prospects of MPEG-CIP in KDP MRF.

  7. An X-band Co2+ EPR study of Zn1-xCoxO (x=0.005-0.1) nanoparticles prepared by chemical hydrolysis methods using diethylene glycol and denaturated alcohol at 5 K

    Misra, Sushil K.; Andronenko, S. I.; Srinivasa Rao, S.; Chess, Jordan; Punnoose, A.

    2015-11-01

    EPR investigations on two types of dilute magnetic semiconductor (DMS) ZnO nanoparticles doped with 0.5-10% Co2+ ions, prepared by two chemical hydrolysis methods, using: (i) diethylene glycol ((CH2CH2OH)2O) (NC-rod-like samples), and (ii) denatured ethanol (CH3CH2OH) solutions (QC-spherical samples), were carried out at X-band (9.5 GHz) at 5 K. The analysis of EPR data for NC samples revealed the presence of several types of EPR lines: (i) two types, intense and weak, of high-spin Co2+ ions in the samples with Co concentration >0.5%; (ii) surface oxygen vacancies, and (iii) a ferromagnetic resonance (FMR) line. QC samples exhibit an intense FMR line and an EPR line due to high-spin Co2+ ions. FMR line is more intense, than the corresponding line exhibited by NC samples. These EPR spectra varied for sample with different doping concentrations. The magnetic states of these samples as revealed by EPR spectra, as well as the origin of ferromagnetism DMS samples are discussed.

  8. Preparation and characterization of PbO2 electrodes doped with polyethylene glycol%聚乙二醇改性不锈钢基PbO2电极的制备及性能研究

    李佳莹; 范莹莹; 陈阵; 余强; 曾丽娟

    2013-01-01

    为了获得电催化性能优良的阳极材料,采用电沉积法制备了不锈钢基聚乙二醇(PEG)改性PbO2电极,通过SEM比较了电极改性前后的形貌变化,通过析氧曲线、Tafel曲线和循环伏安曲线的测量考察了电极材料的催化活性、耐蚀性能.结果表明:经PEG改性的PbO2电极表面平整致密,有较好的电化学性能,有利于难降解苯酚溶液的电催化氧化降解.%In order to obtain anode material with good electrocatalytic activities,PbO2 electrode modified by polyethylene glycol (PEG) was prepared on stainless steel substrate by electrodeposition.The modified variations on surface morphology of the electrodes were examined by Scanning Electron Microscopy (SEM).The properties of the electrodes,such as electrocatalytic activities,corrosion resistance were investigated by oxygen evolution curve,Tafel curve and cyclic voltammetry curves.The results show that modified PbO2 electrode is smooth and compact,and have good electrochemical properties.it will beneficial to degradation of phenol solution.

  9. Preparation and characterization of ibuprofen-loaded microspheres consisting of poly(3-hydroxybutyrate) and methoxy poly (ethylene glycol)-b-poly (D,L-lactide) blends or poly(3-hydroxybutyrate) and gelatin composites for controlled drug release

    Bidone, Juliana; Melo, Ana Paula P. [Laboratorio de Farmacotecnica, Departamento de Ciencias Farmaceuticas, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Bazzo, Giovana C. [Grupo de Estudos em Materiais Polimericos (POLIMAT), Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Carmignan, Francoise [Laboratorio de Farmacotecnica, Departamento de Ciencias Farmaceuticas, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Soldi, Marli S.; Pires, Alfredo T.N. [Grupo de Estudos em Materiais Polimericos (POLIMAT), Departamento de Quimica, Universidade Federal de Santa Catarina, Florianopolis (Brazil); Lemos-Senna, Elenara [Laboratorio de Farmacotecnica, Departamento de Ciencias Farmaceuticas, Universidade Federal de Santa Catarina, Florianopolis (Brazil)], E-mail: lemos@ccs.ufsc.br

    2009-03-01

    Poly-(3-hydroxybutyrate) (P(3HB)) is a biodegradable and biocompatible polymer that has been used to obtain polymer-based drug carriers. However, due to the high crystallinity degree of this polymer, drug release from P(3HB) microspheres frequently occurs at excessive rates. In this study, two strategies for prolonging ibuprofen release from P(3HB)-based microspheres were tested: blending with poly(D,L-lactide)-b-polyethylene glycol (mPEG-PLA); and obtaining composite particles with gelatin (GEL). SEM micrographs showed particles that were spherical and had a rough surface. A slight decrease of the crystallinity degree of P(3HB) was observed only in the DSC thermogram obtained from unloaded-microspheres prepared from 1:1 P(3HB):mPEG-PLA blend. For IBF-loaded microspheres, a reduction of around 10 deg. C in the melting temperature of P(3HB) was observed, indicating that the crystalline structure of the polymer was affected in the presence of the drug. DSC studies also yielded evidence of the presence of a molecular dispersion coexisting with a crystalline dispersion in the drug in the matrix. Similar results were obtained from X-ray diffractograms. In spite of 1:1 mPEG-PLA:P(3HB) blends having contributed to the reduction of the burst effect, a more controlled drug release was provided by the use of the 3:1 P(3HB):mPEGPLA blend. This result indicated that particle hydration played an important role in the drug release. On the other hand, the preparation of P(3HB):GEL composite microspheres did not allow control of the IBF release.

  10. The preparation and characterization of a novel biodiesel named curcas oil diethylene glycol ether ester%一种含醚新型生物柴油的制备与表征

    蒋大勇

    2012-01-01

    以精制麻风树油、甲醇和二乙二醇甲醚为反应物,以KOH为催化剂,制备出一种高含氧量的新型生物柴油——麻风树油二乙二醇甲醚酯.通过正交试验,确定了其最佳合成条件是醇油物质的量比为6∶1,催化剂用量为原料油质量的1.2%,反应温度为65℃,反应时间为30 min.通过FT-IR和1H-NMR分析并验证了产物的分子结构,测试了该生物柴油及其与0#柴油混合的燃料理化性质,包括油溶性、烟点、运动粘度、凝点、闭杯闪点;在相同测试条件下,比较其与伊柴油、麻风树油甲酯的碳烟排放情况.结果表明,麻风树油二乙二醇甲醚酯具有较高的含氧量,其理化性能和排放性能良好,既可以作为柴油添加剂,也可以代替柴油单独进行使用,具有一定的推广应用价值.%In this paper, a novel biodiesel named curcas oil diethylene glycol ether esters (GDGEE) with higher oxygen content was prepared by refined curcas oil, methanol and ethylene glycol monomethyl ether as the reaction and KOH as catalyst., The optimum synthesis conditions were determined by orthogonal test. The molar ratio of methanol to oil was 6:1, catalyst amount was 1.2% of feedstock quality, reaction temperature was 65 ℃, reaction time was 30 minutes. FT-IR and IH-NMR were used to analysis and validate the molecular structure of curcas oil diethylene glycol ether esters. The physical and chemical properties of GDGEE and its blends with 0# diesel oil were tested by the national standard method. The physical and chemical properties include oil soluble, smoke point, kinematic viscosity, freezing point and closed flash point. At last, smoke emission were test among GDGEE, curcas oil methyl and 0# diesel in the same diesel engine. The results confirm that GDGEE owns the higher oxygen content, good physochemical and emission properties, which can be used as diesel fuel additives or also be used instead of diesel fuel alone. A certain application

  11. Synthetic heat carrier oil compositions based on polyalkylene glycols

    The results of syntheses of heat carrier oils based on polyalkylene glycols (PAGs) using suitable additives have been reported. Polyalkylene glycols have been prepared by heating diethylene glycol, propylene oxide, glycols, adipic acid and 2-ethyhexanol in the presence of KOH and stannyl octoate as catalyst in the molar ratio to give proper physical properties and viscosity-temperature index. The prepared PAGs have been taken as basic components for heat carrier oil compositions. In order to improve the thermal stability and viscosity indices, as well as other specifications, anti-oxidant and anti-foaming additives were added to the base material to reach optimum compositions. Thermal stability, mass loss on vaporization at 250 oC, 350 oC and changing the specifications after heating at 300 oC for 10 h have also been investigated. The obtained heat carrier oils showed comparable improved properties in comparison with commercially available heat carriers

  12. Preparation of new ion-selective cross-linked poly(vinylimidazole-co-ethylene glycol dimethacrylate) using a double-imprinting process for the preconcentration of Pb²⁺ ions.

    Tarley, César Ricardo Teixeira; Corazza, Marcela Zanetti; Somera, Bruna Fabrin; Segatelli, Mariana Gava

    2015-07-15

    A new ion-selective cross-linked poly(vinylimidazole-co-ethylene glycol dimethacrylate) prepared via a double-imprinting process was developed for the recognition and preconcentration of Pb(2+) from water samples. The sorbent was characterized by FT-IR, SEM, TGA and textural data. The maximum dynamic sorption capacity of Pb(2+) was 42.04 mg Pb(2+) g(-1) of the double-imprinted polymer. The sorption kinetics data were described by a pseudo-second-order model. The double-imprinted polymer exhibited a higher sorption efficiency of Pb(2+) than the blank polymer (non-imprinted polymer). The preconcentration procedure involved the loading of a Pb(2+) solution at pH 7.25 through 40.0 mg of the double-imprinted polymer packed in a mini-column at 5.0 mL min(-1). The selective efficiency of proposed method for the Pb(2+) preconcentration was assured by competitive sorption using different proportions of Pb(2+)/cations and Pb(2+)/anions. An analytical curve was obtained in the range 0.0-300.0 μg L(-1) (r=0.999) and a limit of detection of 2.46 μg L(-1) was obtained. The preconcentration factor was found to be 21, the consumptive index 0.95 mL and the concentration efficiency 5.25 min(-1). The preconcentration method was successfully applied to the Pb(2+) ions determination in different kinds of water samples with high recovery values (91.3-108.9%). PMID:25823729

  13. Simulated Waste Testing Of Glycolate Impacts On The 2H-Evaporator System

    Martino, C. J.

    2013-08-13

    Glycolic acid is being studied as a total or partial replacement for formic acid in the Defense Waste Processing Facility (DWPF) feed preparation process. After implementation, the recycle stream from DWPF back to the high-level waste tank farm will contain soluble sodium glycolate. Most of the potential impacts of glycolate in the tank farm were addressed via a literature review, but several outstanding issues remained. This report documents the non-radioactive simulant tests impacts of glycolate on storage and evaporation of Savannah River Site high-level waste. The testing for which non-radioactive simulants could be used involved the following: the partitioning of glycolate into the evaporator condensate, the impacts of glycolate on metal solubility, and the impacts of glycolate on the formation and dissolution of sodium aluminosilicate scale within the evaporator. The following are among the conclusions from this work: Evaporator condensate did not contain appreciable amounts of glycolate anion. Of all tests, the highest glycolate concentration in the evaporator condensate was 0.38 mg/L. A significant portion of the tests had glycolate concentration in the condensate at less than the limit of quantification (0.1 mg/L). At ambient conditions, evaporator testing did not show significant effects of glycolate on the soluble components in the evaporator concentrates. Testing with sodalite solids and silicon containing solutions did not show significant effects of glycolate on sodium aluminosilicate formation or dissolution.

  14. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    2010-04-01

    ... milk or preparations intended for addition to milk, as follows: (1) As a coating, binder, plasticizing... dispersing vitamin and/or mineral preparations. (4) As a coating on sodium nitrite to inhibit hygroscopic... glycol in milk....

  15. Preparation, in vitro and in vivo evaluation of polymeric nanoparticles based on hyaluronic acid-poly(butyl cyanoacrylate and D-alpha-tocopheryl polyethylene glycol 1000 succinate for tumor-targeted delivery of morin hydrate

    Abbad S

    2015-01-01

    Full Text Available Sarra Abbad,1,2 Cheng Wang,1 Ayman Yahia Waddad,1 Huixia Lv,1 Jianping Zhou11Department of Pharmaceutics, China Pharmaceutical University, Nanjing, People’s Republic of China; 2Department of Pharmacy, Abou Bekr Belkaid University, Tlemcen, AlgeriaAbstract: Herein, we describe the preparation of a targeted cellular delivery system for morin hydrate (MH, based on a low-molecular-weight hyaluronic acid-poly(butyl cyanoacrylate (HA-PBCA block copolymer. In order to enhance the therapeutic effect of MH, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS was mixed with HA-PBCA during the preparation process. The MH-loaded HA-PBCA “plain” nanoparticle (MH-PNs and HA-PBCA/TPGS “mixed” nanoparticles (MH-MNs were concomitantly characterized in terms of loading efficiency, particle size, zeta potential, critical aggregation concentration, and morphology. The obtained MH-PNs and MH-MNs exhibited a spherical morphology with a negative zeta potential and a particle size less than 200 nm, favorable for drug targeting. Remarkably, the addition of TPGS resulted in about 1.6-fold increase in drug-loading. The in vitro cell viability experiment revealed that MH-MNs enhanced the cytotoxicity of MH in A549 cells compared with MH solution and MH-PNs. Furthermore, blank MNs containing TPGS exhibited selective cytotoxic effects against cancer cells without diminishing the viability of normal cells. In addition, the cellular uptake study indicated that MNs resulted in 2.28-fold higher cellular uptake than that of PNs, in A549 cells. The CD44 receptor competitive inhibition and the internalization pathway studies suggested that the internalization mechanism of the nanoparticles was mediated mainly by the CD44 receptors through a clathrin-dependent endocytic pathway. More importantly, MH-MNs exhibited a higher in vivo antitumor potency and induced more tumor cell apoptosis than did MH-PNs, following intravenous administration to S180 tumor-bearing mice

  16. Polyaniline prepared in ethylene glycol or glycerol

    Konyushenko, Elena; Reynaud, S.; Pellerin, V.; Trchová, Miroslava; Stejskal, Jaroslav; Sapurina, I.

    2011-01-01

    Roč. 52, č. 9 (2011), s. 1900-1907. ISSN 0032-3861 R&D Projects: GA AV ČR IAA400500905; GA ČR GA203/08/0686 Institutional research plan: CEZ:AV0Z40500505 Keywords : conducting polymer * polyaniline * nanotubes Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.438, year: 2011

  17. Glycolic Acid Physical Properties, Impurities, And Radiation Effects Assessment

    The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H2 and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O2 when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be hindered. A series

  18. Degradation and compatibility behaviors of poly(glycolic acid) grafted chitosan

    The films of poly(glycolic acid) grafted chitosan were prepared without using a catalyst to improve the degradable property of chitosan. The films were characterized by Fourier transform-infrared spectroscopy and X-ray photoelectron spectroscopy (XPS). The degradation of the poly(glycolic acid) grafted chitosan films were investigated in the lysozyme solution. In vitro degradation tests revealed that the degradation rate of poly(glycolic acid) grafted chitosan films increased dramatically compared with chitosan. The degradation rate of poly(glycolic acid) grafted chitosan films gradually increased with the increasing of the molar ratio of glycolic acid to chitosan. Additionally, the poly(glycolic acid) grafted chitosan films have good biocompatibility, as demonstrated by in vitro cytotoxicity of the extraction fluids. The biocompatible and biodegradable poly(glycolic acid) grafted chitosan would be an effective material with controllable degradation rate to meet the diverse needs in biomedical fields. - Highlights: ► Chitosan-g-poly(glycolic acid) copolymer was prepared without using a catalyst. ► Degradation rate of copolymer increased dramatically compared with that of chitosan. ► Degradation rate was controlled by the molar ratio of glycolic acid to chitosan. ► In vitro cytotoxicity tests revealed that the copolymer has good biocompatibility. ► The copolymer has a great potential to meet diverse needs in biomedical fields

  19. Brisk Demand of Neopentyl Glycol

    2007-01-01

    @@ Neopentyl glycol (NPG) is an important chemical raw material. It is mainly used to produce saturated polyester resin for powder coatings,unsaturated polyester resin, polyester polyols, esters for synthetic lubricants, plasticizers and alkyd resins.

  20. SYNTHESIS OF NiO NANOPARTICLES IN ETHYLENE GLYCOL

    Desheng Ai; Xiaming Dai; Qingfeng Li; Changsheng Deng; Shinhoo Kang

    2004-01-01

    NiO nanoparticles with well-dispersed property were prepared via a wet chemical method in ethylene glycol (EG) without soluble polymer as a protective agent. The mechanism of chemical process was proposed based on color change during the experiment. The dispersion function of EG was discussed.

  1. Photorespiratory glycolate-glyoxylate metabolism.

    Dellero, Younès; Jossier, Mathieu; Schmitz, Jessica; Maurino, Veronica G; Hodges, Michael

    2016-05-01

    Photorespiration is one of the major carbon metabolism pathways in oxygen-producing photosynthetic organisms. This pathway recycles 2-phosphoglycolate (2-PG), a toxic metabolite, to 3-phosphoglycerate when ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) uses oxygen instead of carbon dioxide. The photorespiratory cycle is in competition with photosynthetic CO2 fixation and it is accompanied by carbon, nitrogen and energy losses. Thus, photorespiration has become a target to improve crop yields. Moreover, during the photorespiratory cycle intermediate metabolites that are toxic to Calvin-Benson cycle and RuBisCO activities, such as 2-PG, glycolate and glyoxylate, are produced. Thus, the presence of an efficient 2-PG/glycolate/glyoxylate 'detoxification' pathway is required to ensure normal development of photosynthetic organisms. Here we review our current knowledge concerning the enzymes that carry out the glycolate-glyoxylate metabolic steps of photorespiration from glycolate production in the chloroplasts to the synthesis of glycine in the peroxisomes. We describe the properties of the proteins involved in glycolate-glyoxylate metabolism in Archaeplastida and the phenotypes observed when knocking down/out these specific photorespiratory players. Advances in our understanding of the regulation of glycolate-glyoxylate metabolism are highlighted. PMID:26994478

  2. Stability of glycol nanofluids -- the consensus between theory and measurement

    Palabiyik, Ibrahim; Witharana, Sanjeeva; Musina, Zenfira; Ding, Yulong

    2012-01-01

    Formulation of stable nanofluids containing ZnO, Al2O3 and TiO2 nanoparticles in propylene glycol (PG), ethylene glycol (EG) and 50wt% mixtures of PG and EG in water (WPG, WEG) were investigated, with and without the presence of surfactants. Nanofluid samples of particle concentrations 1-9wt% were prepared by dispersive method. Surfactant presence was in the range of 0-1wt%/wt% of nanoparticles. Visual observation, particle size measurement and zeta potential analysis were performed to evalua...

  3. GLYCOLIC-FORMIC ACID FLOWSHEET FINAL REPORT FOR DOWNSELECTION DECISION

    Lambert, D.; Pickenheim, B.; Stone, M.; Newell, J.; Best, D.

    2011-03-10

    Flowsheet testing was performed to develop the nitric-glycolic-formic acid flowsheet (referred to as the glycolic-formic flowsheet throughout the rest of the report) as an alternative to the nitric/formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be removed in the Sludge Receipt and Adjustment Tank (SRAT) with minimal hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Forty-six runs were performed in total, including the baseline run and the melter feed preparation runs. Significant results are summarized. The baseline nitric/formic flowsheet run, using the SB6 simulant produced by Harrell was extremely difficult to process successfully under existing DWPF acceptance criteria with this simulant at the HM levels of noble metals. While nitrite was destroyed and mercury was removed to near the DWPF limit, the rheology of the SRAT and SME products were well above design basis and hydrogen generation far exceeded the DWPF SRAT limit. In addition, mixing during the SME cycle was very poor. In this sense, the nitric/glycolic/formic acid flowsheet represents a significant upgrade over the current flowsheet. Mercury was successfully removed with almost no hydrogen generation and the SRAT and SME products yield stresses were within process limits or previously processed ranges. The glycolic-formic flowsheet has a very wide processing window. Testing was completed from 100% to 200% of acid stoichiometry and using a glycolic-formic mixture from 40% to 100% glycolic acid. The testing met all processing requirements throughout these processing windows. This should allow processing at an acid stoichiometry of 100% and a glycolic-formic mixture of 80% glycolic acid with minimal hydrogen generation. It should also allow processing endpoints in the SRAT and SME at significantly higher

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

    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. PMID:23877930

  5. Mixed Micelles made of Poly(ethylene glycol)-Phosphatidylethanolamine Conjugate and D-α-tocopheryl Polyethylene Glycol 1000 Succinate as Pharmaceutical Nanocarriers for Camptothecin

    Mu, L; Elbayoumi, T.A.; Torchilin, V.P.

    2005-01-01

    Micelles from the mixture of poly(ethylene glycol)-phosphatidyl ethanolamine conjugate (PEG-PE) and D-α-tocopheryl polyetheyene glycol 1000 succinate (TPGS) were prepared loaded with the poorly soluble anticancer drug camptothecin (CPT). The solubilization of CPT by the mixed micelles was more efficient than with earlier described micelles made of PEG-PE alone. CPT-loaded mixed micelles were stable upon storage and dilution and firmly retained the incorporated drug. The cytotoxicity of the CP...

  6. Evaluation of the Effect of Low Dose Polyethylene Glycol Electrolyte Powder Combined With Sodium Phosphate in the Preparation of the Intestine%低剂量聚乙二醇电解质散联合磷酸钠用于肠道准备的效果评价

    姜媛媛; 张琰; 李慧华; 李福青

    2015-01-01

    Objective Polyethylene Glycol Electrolytes Powder is safe and effective in endoscopy preparation, but it requires a substantial amount of oral liquid. The purpose of this study is to observe the efficacy of low-dose polyethylene glycol electrolyte powder combined with sodium phosphate fluid compared with standard dose of polyethylene glycol electrolyte powder in endoscopy preparation. We hope that the article can offer some useful help and reference with this kind of research to reduce the amount of oral drugs. Methods Patients were randomly divided into two groups from March 2012 to May 2014. Group A received low-dose polyethylene glycol combined with sodium phosphate before colonoscopy, while group B recieved standard dose of polyethylene glycol electrolyte powder. Compare the effect, adverse reaction safety and compliance of the two groups. Results The quality of the bowel preparation was based on the Boston scale, which shows no significant differences in the two groups. In group A, 203 of 214 patients (95%) can drink 80% of the drugs or more, while in group B 205 of 221 patients (93%) can do that. There was no significant difference between the patients' compliance of the two groups. Based on questionnaire survey about abdominal symptoms in the process of bowel preparation, the incidence of nausea, perianal stimulation, insomnia, abdominal distension was no significance difference between the two groups. The heart rate (HB) and blood pressure (BP) of every patient were monitored before and after the preparation laboratory examinations including hematocrit, serum phosphorous, serum calcium, blood urea nitrogen, and serum creatinine were performed. In group A, after preparation the serum phosphorous and serum sodium of patients was increased and serum calcium and serum potassium was decreased. However, they were within normal limits. There was no significant difference in terms of patients’ serum phosphorous, serum sodium, serum calcium and serum potassium

  7. Glycolate transporter of the pea chloroplast envelope

    The discovery of a glycolate transporter in the pea (Pisum sativum) chloroplast envelope is described. Several novel silicone oil centrifugation methods were developed to resolve the initial rate kinetics of [14C]glycolate transport by isolated, intact pea chloroplasts. Chloroplast glycolate transport was found to be carrier mediated. Transport rates saturated with increasing glycolate concentration. N-Ethylmaleimide (NEM) pretreatment of chloroplasts inhibited transport, an inhibition prevented by glycolate. Glycolate distributed across the envelope in a way which equalized stromal and medium glycolic acid concentrations, limiting possible transport mechanisms to facilitated glycolic acid diffusion, proton symport or hydroxyl antiport. The effects of stomal and medium pH's on the K/sub m/ and V/sub max/ fit the predictions of mobile carrier kinetic models of hydroxyl antiport or proton symport (H+ binds first). The carrier mediated transport was fast enough to be consistent with in vivo rates of photorespiration. The 2-hydroxymonocarboxylates, glycerate, lactate and glyoxylate are competitive inhibitors of chloroplast glycolate uptake. Glyoxylate, D-lactate and D-glycerate cause glycolate counterflow, indicating that they are also substrates of the glycolate carrier. This finding was confirmed for D-glycerate by studies on glycolate effects on [1-14C]D-glycerate transport

  8. Preparation and quality control of compound epirubicin hydrochloride-loaded polymeric nanoparticles of L-lactic-co-glycolic acid%复方盐酸表柔比星聚乳酸-羟基乙酸共聚物纳米粒的制备及含量测定

    纪建松; 傅红兴; 宋晶晶; 李慧; 朱雁林

    2011-01-01

    目的 制备复方盐酸表柔比星聚乳酸-羟基乙酸共聚物( PLGA)纳米粒,并对其含量进行测定.方法 采用乳化-溶剂挥发法制备复方盐酸表柔比星纳米粒,添加适量乳糖后采用冷冻干燥法制备得到复方盐酸表柔比星纳米粒冻干粉,通过反相高效液相法测定盐酸表柔比星和钆喷酸双葡甲胺的含量和释放度.结果 制备得到复方盐酸表柔比星PLGA纳米粒,初步建立了可同时测定两种药物成分的高效液相含量测定方法,复方制剂中盐酸表柔比星和钆喷酸双葡甲胺的含量分别为100.6%±1.6%、99.1%±1.9%,且两种成分均能在9d内释放完全.结论 本方法制备复方盐酸表柔比星PLGA纳米粒简便可行,所拟定的含量测定方法可行.%Objective To prepare compound epirubicin hydrochloride-loaded polymeric nanoparticles of L-lactic-co-glycolic acid and establish their quality control.Methods The emulsion-solvent evaporation method was employed to prepare and freeze-dry the compound epirubicin hydrochloride-loaded polymeric nanoparticles of L-lactic-co-glycolic acid after the addition of lactose.The contents and cumulative release of epirubicin hydrochloride and dimeglumine gadopentetate were detected simultaneously by RPHPLC (reverse phase-high performance liquid chromatography).Results The above nanoparticles were prepared and the quality standards for simultaneously determining the contents of epirubicin hydrochloride and dimeglumine gadopentetate established primarily.The contents of epirubicin hydrochloride and dimeglumine gadopentetate in compound preparation were 100.6% ± 1.6% and 99.1% ± 1.9%respectively.And two compositions could be completely released within 9 days.Conclusion The preparation method of nanoparticles is simple and their quality control feasible.

  9. Study of Synthesis of Copoly (lactic acid/glycolic acid) by Direct Melt Polycondensation

    LAN Ping; GAO Qin-wei; SHAO Hui-li; HU Xue-chao

    2005-01-01

    A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/ptoluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.

  10. Drying poly(ethylene glycol)

    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 ...

  11. Upstream petroleum industry glycol dehydrator benzene emissions status report

    The population of dehydrators referred to are located in the Western Sedimentary Basin in northeast British Columbia, Alberta and Saskatchewan, and includes units installed at wellsites, compressor stations, gas plants, central crude oil treating facilities, and reservoir or salt cavern gas storage facilities. Benzene emissions from the still column vent on glycol dehydrators occur as a result of glycol's strong affinity for aromatic hydrocarbons, including benzene. A study was carried out to: 1) develop a list of oil and gas companies operating in Canada, 2) develop an equipment and benzene emissions inventory of glycol dehydrators, 3) develop a database in Microsoft Access format to gather and maintain inventory and emission data, 4) evaluate and validate at least 10% of the reported data, 5) develop a list of companies that manufacture dehydrators and incinerators to determine how many new dehydrators were sold for use in Canada in 1998, and 6) prepare a report summarizing findings and recommendations. The companies included in the survey were the oil and gas companies identified by the Nickels' Oil and Gas Index and others provided by CAPP, CGA, and SEPAC. The project was carried out to gather glycol dehydrator equipment and still column vent benzene emissions information. 8 refs

  12. Characterization of gliclazide-polyethylene glycol solid dispersion and its effect on dissolution

    Moreshwar Pandharinath Patil; Naresh Janardan Gaikwad

    2011-01-01

    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...

  13. The world of DNA in glycol solution.

    Lindahl, Tomas

    2016-05-23

    The properties of high-molecular-weight DNA are usually investigated in neutral aqueous solutions. Strong acids and strong alkaline solutions are obviously unsuitable, as are corrosive solvents, and DNA is insoluble in most organic solvents; precipitation of DNA from aqueous solution with ethanol or isopropanol is therefore frequently used as a purification step. An exception is the organic solvent glycol (ethylene glycol, 1,2-ethanediol, dihydroxyethane, HOCH2CH2OH) and the similar solvent glycerol. Double-stranded DNA remains soluble in salt-containing glycol, although it precipitates in polyethylene glycol. (DNA also remains soluble in formamide, but the double-helical structure of DNA is much less stable in this solvent than in glycol.) However, DNA in glycol has been little investigated during the last half-century. PMID:27211487

  14. Ethylene glycol, hazardous substance in the household.

    Patocka, Jirí; Hon, Zdenek

    2010-01-01

    Ethylene glycol is a colorless, odorless, sweet-tasting but poisonous type of alcohol found in many household products. The major use of ethylene glycol is as an antifreeze in, for example, automobiles, in air conditioning systems, in de-icing fluid for windshields, and else. People sometimes drink ethylene glycol mistakenly or on purpose as a substitute for alcohol. Ethylene glycol is toxic, and its drinking should be considered a medical emergency. The major danger from ethylene glycol is following ingestion. Due to its sweet taste, peoples and occasionally animals will sometimes consume large quantities of it if given access to antifreeze. While ethylene glycol itself has a relatively low degree of toxicity, its metabolites are responsible for extensive cellular damage to various tissues, especially the kidneys. This injury is caused by the metabolites, glycolic and oxalic acid and their respective salts, through crystal formation and possibly other mechanisms. Toxic metabolites of ethylene glycol can damage the brain, liver, kidneys, and lungs. The poisoning causes disturbances in the metabolism pathways, including metabolic acidosis. The disturbances may be severe enough to cause profound shock, organ failure, and death. Ethylene glycol is a common poisoning requiring antidotal treatment. PMID:20608228

  15. Review of glycol ether and glycol ether ester solvents used in the coating industry.

    Smith, R.L.

    1984-01-01

    Ethylene oxide-based glycol ether and glycol ether ester solvents have been used in the coatings industry for the past fifty years. Because of their excellent performance properties (evaporation rate, blush resistance, flow-out and leveling properties, solubility for coating resins, solvent activity, mild odor, good coupling ability, good solvent release) a complete line of ethylene oxide-based solvents of various molecular weights has been developed. These glycol ether and glycol ether ester...

  16. Sorbitol hydrogenolysis to glycols by supported ruthenium catalysts

    Inmaculada Murillo Leo; Manuel Lopez Granados; Jose Luis Garcia Fierro; Rafael Mariscal

    2014-01-01

    Supported Ru catalysts were prepared by wet impregnation to evaluate the role of different oxide supports (Al2O3, SiO2, TiO2, ZrO2) in sorbitol hydrogenolysis to glycols. X-ray diffraction, transmis-sion electron microscopy, hydrogen chemisorption, X-ray photoelectron spectroscopy, and NH3 temperature-programmed desorption were used to characterize the catalysts, which were active in the hydrogenolysis of sorbitol. The support affected both the physicochemical properties and cata-lytic behavior of the supported Ru particles. The characterization results revealed that the Ru/Al2O3 catalyst has a high surface acidity, partially oxidized Ru species on the surface, and a higher surface Ru/Al atomic ratio, which gave it the highest selectivity and yield to glycols.

  17. LITERATURE REVIEW ON IMPACT OF GLYCOLATE ON THE 2H EVAPORATOR AND THE EFFLUENT TREATMENT FACILITY

    Adu-Wusu, K.

    2012-05-10

    Glycolic acid (GA) is being studied as an alternate reductant in the Defense Waste Processing Facility (DWPF) feed preparation process. It will either be a total or partial replacement for the formic acid that is currently used. A literature review has been conducted on the impact of glycolate on two post-DWPF downstream systems - the 2H Evaporator system and the Effluent Treatment Facility (ETF). The DWPF recycle stream serves as a portion of the feed to the 2H Evaporator. Glycolate enters the evaporator system from the glycolate in the recycle stream. The overhead (i.e., condensed phase) from the 2H Evaporator serves as a portion of the feed to the ETF. The literature search revealed that virtually no impact is anticipated for the 2H Evaporator. Glycolate may help reduce scale formation in the evaporator due to its high complexing ability. The drawback of the solubilizing ability is the potential impact on the criticality analysis of the 2H Evaporator system. It is recommended that at least a theoretical evaluation to confirm the finding that no self-propagating violent reactions with nitrate/nitrites will occur should be performed. Similarly, identification of sources of ignition relevant to glycolate and/or update of the composite flammability analysis to reflect the effects from the glycolate additions for the 2H Evaporator system are in order. An evaluation of the 2H Evaporator criticality analysis is also needed. A determination of the amount or fraction of the glycolate in the evaporator overhead is critical to more accurately assess its impact on the ETF. Hence, use of predictive models like OLI Environmental Simulation Package Software (OLI/ESP) and/or testing are recommended for the determination of the glycolate concentration in the overhead. The impact on the ETF depends on the concentration of glycolate in the ETF feed. The impact is classified as minor for feed glycolate concentrations {le} 33 mg/L or 0.44 mM. The ETF unit operations that will have

  18. Ethylene glycol aluminum as a novel catalyst for the synthesis of poly(ethylene terephthalate)

    Bin Xiao; Li Ping Wang; Ren Hao Mei; Gong Ying Wang

    2011-01-01

    Ethylene glycol aluminum was prepared efficiently and characterized by FT-IR and NMR. It exhibited higher catalytic activity and had profitable effect than titanium glycolate and ethylene glycol antimony for the synthesis of poly(ethylene terephthalate) (PET). It was only used as polycondensation catalyst because it was sensitive to water. For this catalyst, the degree of esterification of the theoretical amount of water was produced up to 95% at 260 ℃, while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PET polyester, polymerized at 280℃, 70 Pa for 39 min, was 0.87 dL/g and 23.0 μmol/g, respectively. Ethylene glycol aluminum was a promising catalyst for the synthesis of PET polyester.

  19. Influence of Ethylene Glycol on the Formation of Calcium Phosphate Nanocrystals

    Yi ZUO; Yubao LI; Jie WEI; Yonggang YAN

    2003-01-01

    A synthesis route of using calcium hydroxide Ca(OH)2 with ethylene glycol solvent and orthophosphoric acid (H3PO4)as reagents is described. Three ratios of ethylene glycol to distilled water 1:0, 1:1 and 0:1 are used as diluting media for Ca(OH)2. Crystals of different morphology and composition are formed under weak alkaline circumstance at pH 7.0~8.0. Acicular calcium phosphate nanocrystals are prepared in pure ethylene glycol while rod-like calcium phosphate nanocrystals form in pure distilled water. The nanograde size of the former is smaller than that of the latter. Calcium-deficient apatite (CDAP) is obtained with a Ca/P molar ratio of 1.66. Therefore, it was deduced that the usage of ethylene glycol solvent could influence the formation of calcium phosphate crystal lattice.

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

    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. PMID:26703197

  1. PLGA纳米可降解尿道支架的制备及力学性能%Preparation and mechanical properties of co-polymer poly (lactic-co-glycolic acid) degradable tubular urethral scaffold

    王晓庆; 王春喜; 侯宇川; 陈岐辉; 张海峰; 姜凤鸣

    2012-01-01

    Objective To discuss the feasibility of the fabrication of co-polymer poly (lactic-co-glycolic acid) (PLGA) 80 : 20 tubular urethral scaffold by electrospinning and evaluate its mechanical properties. Methods PLGA (80 : 20) was dissolved in chloroform to form solutions with concentrations varying from 3% to 6%. The electrospinning technique was used to fabricate the tubular urethral scaffolds. The morphology was investigated by scanning electron microscope. Fiber diameters, aperture, porosity and mechanical properties were compared between various concentrations of PLGA. Results PLGA urethral stents with concentrations of 3% , A% and 5% were successfully fabricated, and the concentration of 6% failed for high concentration. The scaffold was 4 cm long and with an inner diameter of 3. 0 mm and an outside diameter of 4. 0 mm. The fiber diameter was thicken with the increasing of the concentrations, the difference was significant between various groups (P 0.05). Conclusion The properties of 5% PLGA (80 : 20) urethral scaffold which fabricated by electrospinriing technique can fully satisfied the demand for structure and mechanical properties of a degradable urethral scaffold.%目的:探讨电纺丝法制备聚乳酸-羟基乙酸共聚物(PLGA)(摩尔比80:20)可降解尿道支架的可行性,并评价支架管的力学性能.方法:PLGA (80:20)用三氯甲烷溶解并配成3%、4%、5%和6%的溶液,采用电纺丝技术制备纳米尿道支架,采用扫描电镜观察各种浓度PLGA制备的纳米尿道支架的微观结构,比较各种浓度PLGA支架的纤维直径、孔径、孔隙率及力学性能的差异.结果:浓度为3%、4%和5%的PLGA尿道支架制备成功,浓度为6%的PLGA因浓度过高制管失败.支架呈白色,长度4 cm,内径约3.0 mm,外径约4.0 mm.电镜扫描见3种浓度的PLGA支架纤维平均直径随浓度的增高而增粗,组间比较差异有统计学意义(P<0.05).3种浓度PLGA支架的平均孔径分别为(7±4

  2. Triethylene glycol bis(2-ethylhexanoate) - a new contact allergen identified in a spectacle frame

    Andersen, Klaus Ejner; Vestergaard, M. E.; Christensen, Lars Porskjær

    2014-01-01

    patient's spectacle frame. Materials and methods. An extract from the temple arms was analysed by gas chromatography mass spectrometry (GC-MS), and a major low molecular weight compound was detected. This compound was isolated by semi-preparative high-performance liquid chromatography and identified by GC-MS...... and nuclear magnetic resonance spectroscopy. The purified compound was diluted in ethanol, and a dilution series was prepared for patch testing. Results. Triethylene glycol bis(2-ethylhexanoate) was identified as the major compound in the extract. Patch testing of the patient proved that triethylene...... glycol bis(2-ethylhexanoate) was the causative allergen in the spectacle frame. Ten consecutive eczema patients tested as controls were negative. Conclusion. Triethylene glycol bis(2-ethylhexanoate) is a new, hitherto unreported contact allergen....

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

    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. PMID:23048065

  4. Effect of polyethylene glycol on characteristics of chitosan membranes

    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.

  5. Ethylene glycol causes acyl chain disordering in liquid-crystalline, unsaturated phospholipid model membranes, as measured by 2H NMR

    NICOLAY K; Smaal, E B; de Kruijff, B.

    1986-01-01

    2H NMR has been used to probe the effects of ethylene glycol at the level of the acyl chains in liposomes prepared from dioleoylphosphatidic acid or dioleoylphosphatidylcholine, labeled with 2H at the 11-position of both oleic acid chains. Increasing concentrations of ethylene glycol lead to a proportional and substantial decrease in the quadrupolar splittings, measured from the 2H NMR spectra of both liposomal systems, indicative of acyl chain disordering.

  6. Ethylene glycol causes acyl chain disordering in liquid-crystalline, unsaturated phospholipid model membranes, as measured by 2H NMR

    2H NMR has been used to probe the effects of ethylene glycol at the level of the acyl chains in liposomes prepared from dioleoylphosphatidic acid or dioleoylphosphatidylcholine, labeled with 2H at the 11-position of both oleic acid chains. Increasing concentrations of ethylene glycol lead to a proportional and substantial decrease in the quadrupolar splittings, measured from the 2H NMR spectra of both liposomal system, indicative of acyl chain disordering. (Auth.)

  7. Experimental investigation in thermal conductivity of CuO and ethylene glycol nanofluid in serpentine shaped microchannel

    Mr. A. Sivakumar; Dr.N. Alagumurthi; Dr.T.Senthilvelan

    2014-01-01

    This research work investigates the thermal conductivity and viscosity of copper oxide nanoparticles in ethylene glycol. The copper oxide was dispersed in ethylene glycol using a sonicator. The nanofluid suspension were prepared for different concentration upto 0.3%. The heat transfer principle states that maximum heat transfer is achieved in microchannels with minimum pressure drop across it. The increase in viscosity was about four times of that predicted by the Einstein law of viscosity. I...

  8. Maximizing adhesion of auxin solutions to stem cuttings using sodium cellulose glycolate

    Auxin solutions prepared with sodium cellulose glycolate (SCG; a thickening agent, also known as sodium carboxymethylcellulose) and applied to stem cuttings using a basal quick-dip extend the duration of exposure of cuttings to the auxin and have previously been shown to increase root number and/or ...

  9. Glycol methacrylate embedding for light microscopy : Basic principles and trouble-shooting

    Gerrits, PO; Horobin, RW

    1996-01-01

    Acrylic resin mixtures are now widely used as embedding media for the preparation of tissue sections. Most of these mixtures are based on 2-hydroxyethyl methacrylate (glycol methacrylate, GMA). Resin embedding preserves tissue components far better than paraffin, celloidin or frozen sections. The pr

  10. An X-band Co{sup 2+} EPR study of Zn{sub 1−x}Co{sub x}O (x=0.005–0.1) nanoparticles prepared by chemical hydrolysis methods using diethylene glycol and denaturated alcohol at 5 K

    Misra, Sushil K., E-mail: skmisra@alcor.concordia.ca [Physics Department, Concordia University, Montreal, QC, Canada H3G 1M8 (Canada); Andronenko, S.I. [Physics Institute, Kazan Federal University, Kazan 420008 (Russian Federation); Srinivasa Rao, S.; Chess, Jordan; Punnoose, A. [Department of Physics, Boise State University, Boise, ID 83725-1570 (United States)

    2015-11-15

    EPR investigations on two types of dilute magnetic semiconductor (DMS) ZnO nanoparticles doped with 0.5–10% Co{sup 2+} ions, prepared by two chemical hydrolysis methods, using: (i) diethylene glycol ((CH{sub 2}CH{sub 2}OH){sub 2}O) (NC-rod-like samples), and (ii) denatured ethanol (CH{sub 3}CH{sub 2}OH) solutions (QC-spherical samples), were carried out at X-band (9.5 GHz) at 5 K. The analysis of EPR data for NC samples revealed the presence of several types of EPR lines: (i) two types, intense and weak, of high-spin Co{sup 2+} ions in the samples with Co concentration >0.5%; (ii) surface oxygen vacancies, and (iii) a ferromagnetic resonance (FMR) line. QC samples exhibit an intense FMR line and an EPR line due to high-spin Co{sup 2+} ions. FMR line is more intense, than the corresponding line exhibited by NC samples. These EPR spectra varied for sample with different doping concentrations. The magnetic states of these samples as revealed by EPR spectra, as well as the origin of ferromagnetism DMS samples are discussed. - Highlights: • 5 K X band Co{sup 2+} EPR investigations on QC and NC ZnO dilute magnetic semiconductor nanoparticles. • NC and QC samples exhibited high-spin Co{sup 2+} EPR lines and ferromagnetic resonance line. • NC sample also exhibit line due surface oxygen vacancies. • FMR line is more intense in QC than that in NC samples. • Magnetic states and the origin of ferromagnetism are discussed.

  11. Preparation of Glycol-Fosfomycin Modified Zirconia Chromatography Stationary Phases and Its Application to the Separation of Proteins%乙二醇-磷霉素改性氧化锆色谱固定相的制备及其在蛋白质分离中的应用

    张淑琼; 邹凤平; 李烃

    2009-01-01

    A novel glycol-fosfomycin modified zirconia (G-F-ZrO_2) stationary phase was prepared and characterized by elemental analysis, FT-IR and N_2 adsorption. Its chromatographic performance was evaluated using four standard proteins including lysozyme (Lys), ribonuclease-A (Rnase-A), α-chymotrypsin (α-Chy) and Cytochrome C (Cyt-C) as probes, and the effects of salt concentration, pH, salt type in eluents and temperature on retention behavior of proteins were investigated. The results indicate that the stationary phase behaves mainly as a hydrophobic interaction chromatographic packing with salt concentration in the mobile phase above 1.0 moh·L~(-1). At the same time, the retention mechanism between protein and G-F-ZrO_2 stationary phase was also discussed.%合成了分离蛋白质的乙二醇-磷霉素钠改性氧化锆高效液相色谱固定相,通过漫反射红外光谱、元素分析等分析方法对该固定相进行了表征.以溶菌酶、核糖核酸酶A、细胞色素C和糜蛋白酶四种标准碱性蛋白质为探针,系统地考察了固定相的疏水相互作用色谱性能.结果表明,乙二醇-磷霉素改性氧化锆固定相对蛋白质有一定的保留,表现出较高的分离选择性.

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

    Yukio Nagasaki

    2010-01-01

    A poly(ethylene glycol)-b-poly[2-(N,N-dimethylamino)ethyl 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 ha...

  13. Viscoelasticity of repaired sciatic nerve by poly(lactic-co-glycolic acid) tubes

    Chengdong Piao; Peng Li; Guangyao Liu; Kun Yang

    2013-01-01

    Medical-grade synthetic poly(lactic-co-glycolic acid) polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly(lactic-co-glycolic acid) tubes. Ten sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly(lactic-co-glycolic acid) tubes. Stress relaxation and creep testing showed that at 7 200 seconds, the sciatic nerve anastomosed by poly(lactic-co-glycolic acid) tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly(lactic-co-glycolic acid) exhibits good viscoelasticity to meet the biomechanical require-ments for a biomaterial used to repair sciatic nerve injury.

  14. Ultrasonic studies of liquid mixtures of either water or dimethylsulfoxide with ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propylene glycol and 1,4-butylene glycol at 298.15 K

    Tsierkezos, Nikos; Palaiologou, M. M.

    2009-01-01

    Roč. 47, č. 4 (2009), s. 447-459. ISSN 0031-9104 Institutional research plan: CEZ:AV0Z40550506 Keywords : binary mixtures * glycols * thermochemical properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.580, year: 2009

  15. Safety assessment of propylene glycol, tripropylene glycol, and PPGs as used in cosmetics.

    Fiume, Monice M; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2012-01-01

    Propylene glycol is an aliphatic alcohol that functions as a skin conditioning agent, viscosity decreasing agent, solvent, and fragrance ingredient in cosmetics. Tripropylene glycol functions as a humectant, antioxidant, and emulsion stabilizer. Polypropylene glycols (PPGs), including PPG-3, PPG-7, PPG-9, PPG-12, PPG-13, PPG-15, PPG-16, PPG-17, PPG-20, PPG-26, PPG-30, PPG-33, PPG-34, PPG-51, PPG-52, and PPG-69, function primarily as skin conditioning agents, with some solvent use. The majority of the safety and toxicity information presented is for propylene glycol (PG). Propylene glycol is generally nontoxic and is noncarcinogenic. Clinical studies demonstrated an absence of dermal sensitization at use concentrations, although concerns about irritation remained. The CIR Expert Panel determined that the available information support the safety of tripropylene glycol as well as all the PPGs. The Expert Panel concluded that PG, tripropylene glycol, and PPGs ≥3 are safe as used in cosmetic formulations when formulated to be nonirritating. PMID:23064775

  16. Transport and metabolism of glycolic acid by Chlamydomonas reinhardtii

    In order to understand the excretion of glycolate from Chlamydomonas reinhardtii, the conditions affecting glycolate synthesis and metabolism were investigated. Although glycolate is synthesized only in the light, the metabolism occurs in the light and dark with greater metabolism in the light due to refixation of photorespiratory CO2. The amount of internal glycolate will affect the metabolism of externally added glycolate. When glycolate synthesis exceeds the metabolic capacity, glycolate is excreted from the cell. The transport of glycolate into the cells occurs very rapidly. Equilibrium is achieved at 40C within the time cells are pelleted by the silicone oil centrifugation technique through a layer of [14C] glycolate. Glycolate uptake does not show the same time, temperature and pH dependencies as diffusion of benzoate. Uptake can be inhibited by treatment of cells with N-ethylmaleimide and stimulated in the presence of valino-mycin/KCl. Acetate and lactate are taken up as quickly as glycolate. The hypothesis was made that glycolate is transported by a protein carrier that transports monocarboxylic acids. The equilibrium concentration of glycolate is dependent on the cell density, implying that there may be a large number of transporter sites and that uptake is limited by substrate availability

  17. Stability of glycol nanofluids -- the consensus between theory and measurement

    Palabiyik, Ibrahim; Musina, Zenfira; Ding, Yulong

    2012-01-01

    Formulation of stable nanofluids containing ZnO, Al2O3 and TiO2 nanoparticles in propylene glycol (PG), ethylene glycol (EG) and 50wt% mixtures of PG and EG in water (WPG, WEG) were investigated, with and without the presence of surfactants. Nanofluid samples of particle concentrations 1-9wt% were prepared by dispersive method. Surfactant presence was in the range of 0-1wt%/wt% of nanoparticles. Visual observation, particle size measurement and zeta potential analysis were performed to evaluate the dispersion stability. In overall the PG-based samples were found to be the most stable suspensions. The effect of base fluid on particle size and the effect of day light on nanofluid stability were also examined as a function of time. TiO2-PG samples showed a colour change when exposed to sunlight. Sunlight also caused the PG based TiO2 and Al2O3 nanofluid to increase their particle sizes by up to 45% in the course of 3 days. As for stability, the sedimentation velocity was observed to be a key parameter. Finally b...

  18. Synthesis and properties of copper nanoparticles stabilized by polyethylene glycol

    The composite nanoparticles containing metallic copper and copper (I) oxide were synthesized by reduction of copper sulfate with sodium borohydride in the presence of polyethylene glycol. The effect of reactant ratio and reaction time on the morphology and phase composition of the obtained nanoparticles was investigated by transmission electron microscopy and X-ray phase analysis. It was shown that the factor which most greatly influences the particle size is the content of polyethylene glycol (PEG) in the reaction mixture – with increasing PEG content average particle size determined by transmission electron microscopy, reduced from 22,0 to 14,0 nm. The reaction time and the ratio of copper sulfate and sodium borohydride have small effect on the average size and coherent scattering dimensions of nanoparticles formed. In accordance with the results of X-ray phase analysis in all cases the biphasic particles containing metallic copper and copper oxide (I) formed regardless of reaction condition. The relative content of Cu2O in samples varies from 11,5 to 44,1 wt. %. Among the samples obtained and researched the sample prepared at an equimolar ratio of copper sulfate and sodium borohydride has a special place. It is characterized by a high content of copper oxide (I), a bimodal distribution of particle size and the largest average particle size. (authors)

  19. Oral insulin delivery using P(MAA-g-EG) hydrogels: effects of network morphology on insulin delivery characteristics.

    Nakamura, Koji; Murray, Robert J; Joseph, Jeffrey I; Peppas, Nicholas A; Morishita, Mariko; Lowman, Anthony M

    2004-03-24

    Hydrogels of poly(methacrylic acid-g-ethylene glycol) were prepared using different reaction water contents in order to vary the network mesh size, swelling behavior and insulin loading/release kinetics. Gels prepared with greater reaction solvent contents swelled to a greater degree and had a larger network mesh size. All of the hydrogels were able to incorporate insulin and protected it from release in acidic media. At higher pH (7.4), the release rates increased with reaction solvent content. Using a closed loop animal model, all of the insulin loaded formulations produced significant insulin absorption in the upper small intestine combined with hypoglycemic effects. In these studies, bioavailabilities ranged from 4.6% to 7.2% and were dependent on reaction solvent content. PMID:15023469

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

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

  1. 21 CFR 582.1666 - Propylene glycol.

    2010-04-01

    ... is generally recognized as safe (except in cat food) when used in accordance with good manufacturing... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol. 582.1666 Section 582.1666 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  2. Stabilization of Polyethylene Glycol in Archaeological Wood

    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 f...

  3. Anaerobic treatment of glycol contaminated wastewater for methane production

    Agbalakwe, Ekene

    2011-01-01

    Glycols are usually used in the offshore gas industry as hydrate inhibitor in gas pipelines laid deep under the sea. Glycols, in its use, are contaminated by dissolved salts from formation water together with scaling and corrosion products from the pipeline. This results to generation of wastewater containing glycols. Anaerobic treatment may represent an alternative to the aerobic treatment of glycol wastewater. Laboratory-scale studies were carried out to investigate the treatability of glyc...

  4. Effect observation of taking polyethylene glycol-electrolyte solution at different time on bowel preparation in elderly for colonscopy%老年患者不同时间服用复方聚乙二醇电解质散肠道准备的效果

    董云; 郭光艳; 林海

    2015-01-01

    Objective To compare the efficacy and side effects of split-dose Polyethylene glycol-electrolyte solution ( PEG ) with full-dose preparation in the elderly for colonoscopy, and to summary the experience of nursing care. Methods A total of 220 elderly undergoing colonoscopy were randomly divided into experimental group ( group A) and control group ( group B) , 110 cases in each group. Group A took half the dose of PEG (1. 5 L) at 5 PM on the day before colonoscopy and the remaining half (1. 5 L) were instructed to drink at 6 AM on the day of colonoscopy. Group B took all the PEG (3 L) at 6 AM on the day of colonoscopy. The quality of bowel cleansing was assessed according to the Boston bowel preparation scale ( BBPS) , and side effects ( nausea, vomiting, abdominal pain, fatigue and hunger ) and complication were also observed. In addition, the polyps and tumors of colon detection were compared within the two groups. Results The level of bowel preparation in group A was superior to group B [(6. 65 ± 1. 67) vs (6. 14 ± 1. 91, t =2. 097, P <0. 05)], however, the incidence of side effects such as nausea and vomiting, abdominal pain and bloating in group A were 14 cases, 34 cases and 22 cases less than those of group B (χ2 =4. 400,4. 111,4. 002,respectively;P<0. 05). The detection rate of colonic polyps and tumors in group A (37. 3%) were also higher than that of group B (24. 5%) (χ2 =4. 172, P<0. 05). Conclusions The use of a split-dose PEG for bowel preparation before colonoscopy significantly improved bowel preparation. Split-dose preparation is associated with a lower incidence of side effects, and higher detection rate of colonic polyps and tumors in the elderly.%目的:比较老年患者分次剂量与单次全剂量服用复方聚乙二醇电解质溶液进行肠道准备的效果及不良反应,总结肠道准备的护理经验。方法将220例行结肠镜检查的老年患者根据计算机生成的随机数字表分为试验组和对照组,每组110例

  5. Sources of Propylene Glycol and Glycol Ethers in Air at Home

    Hyunok Choi; Norbert Schmidbauer; John Spengler; Carl-Gustaf Bornehag

    2010-01-01

    Propylene glycol and glycol ether (PGE) in indoor air have recently been associated with asthma and allergies as well as sensitization in children. In this follow-up report, sources of the PGEs in indoor air were investigated in 390 homes of pre-school age children in Sweden. Professional building inspectors examined each home for water damages, mold odour, building’s structural characteristics, indoor temperature, absolute humidity and air exchange rate. They also collected air and dust samp...

  6. 40 CFR 721.3550 - Dipropylene glycol dimethyl ether.

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Dipropylene glycol dimethyl ether. 721... Substances § 721.3550 Dipropylene glycol dimethyl ether. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as dipropylene glycol dimethyl ether (PMN...

  7. 40 CFR 799.4440 - Triethylene glycol monomethyl ether.

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Triethylene glycol monomethyl ether... REQUIREMENTS Specific Chemical Test Rules § 799.4440 Triethylene glycol monomethyl ether. (a) Identification of test substance. (1) Triethylene glycol monomethyl ether (TGME, CAS No. 112-35-6) shall be tested...

  8. Isothermal Crystallization Kinetics of Microencapsulated Polyethylene Glycol Particles

    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.

  9. The effect of polyethylene glycol on shellac stability

    Khairuddin; Pramono, Edi; Budi Utomo, Suryadi; Wulandari, Viki; A'an Zahrotul, W.; Clegg, Francis

    2016-02-01

    The effect of polyethylene glycol (PEG) having amolecular weight of 1000 and 2000 on shellac stability has been investigated in this research. The shellac was shellac wax free, and the solvent was ethanol 96%. Shellac films were prepared by solventevaporationmethod. The stability of shellac was investigated using insoluble solid test, Fourier Transform Infra Red (FTIR), Thermogravimetry Analyzer (TGA), and Water Vapour Transmission Rate (WVTR). The results showed that stability of shellac decreased after heating at 125oC for 10,30,90,and 180 minutes, and storing for 1 month at 27 oC and 85 relative humidity (RH). PEG improved the stability, and the most stable effect was achieved through PEG1000.

  10. Poly(ethylene glycol) grafted chitosan as new copolymer material for oral delivery of insulin

    Ho, Thanh Ha; Thanh Le, Thi Nu; Nguyen, Tuan Anh; Chien Dang, Mau

    2015-09-01

    A new scheme of grafting poly (ethylene glycol) onto chitosan was proposed in this study to give new material for delivery of insulin over oral pathway. First, methoxy poly(ethylene glycol) amine (mPEGa MW 2000) were grafted onto chitosan (CS) through multiples steps to synthesize the grafting copolymer PEG-g-CS. After each synthesis step, chitosan and its derivatives were characterized by FTIR, 1H NMR Then, insulin loaded PEG-g-CS nanoparticles were prepared by cross-linking of CS with sodium tripolyphosphate (TPP). Same insulin loaded nanoparticles using unmodified chitosan were also prepared in order to compare with the modified ones. Results showed better protecting capacity of the synthesized copolymer over original CS. CS nanoparticles (10 nm of size) were gel like and high sensible to temperature as well as acidic environment while PEG-g-CS nanoparticles (200 nm of size) were rigid and more thermo and pH stable.

  11. Degradation and miscibility of poly(DL-lactic acid)/poly(glycolic acid) composite films: Effect of poly(DL-lactic-co-glycolic acid)

    Zhigang Ma; Na Zhao; Chengdong Xiong

    2012-08-01

    The in vitro degradation behaviour of poly(glycolic acid) (PGA) and its composite films containing poly(DL-lactic acid) (PDLLA) and poly(DL-lactic-co-glycolic acid) (PDLGA) were investigated via mass loss, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). All the films were prepared by solution casting, using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. Since the degradation rate of PDLLA is lower than that of PGA, those of the PDLLA/PGA composite films decreased. As a compatibilizer, PDLGA improved the compatibility and hydrolytic stability of PDLLA/PGA composite films. Changes in the composite films indicate that this kind of PGA-based composite biomaterial may be applicable to device design for clinical application in the future.

  12. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    2010-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene......

  13. GLYCOLIC-FORMIC ACID FLOWSHEET SLUDGE MATRIX STUDY

    Lambert, D.; Koopman, D.

    2011-06-30

    Testing was completed to demonstrate the viability of the newly developed glycolic acid/formic acid flowsheet on processing in the Defense Waste Processing Facility's (DWPF) Chemical Process Cell (CPC). The Savannah River National Laboratory (SRNL) initiated a sludge matrix study to evaluate the impact of changing insoluble solid composition on the processing characteristics of slurries in DWPF. Four sludge simulants were prepared to cover two compositional ranges in the waste. The first was high iron/low aluminum versus low iron/high aluminum (referred to as HiFe or LoFe in this report). The second was high calcium-manganese/low nickel, chromium, and magnesium versus low calcium-manganese/high nickel, chromium, and magnesium (referred to as HiMn or LoMn in this report). These two options can be combined to form four distinct sludge compositions. The sludge matrix study called for testing each of these four simulants near the minimum acid required for nitrite destruction (100% acid stoichiometry) and at a second acid level that produced significant hydrogen by noble metal catalyzed decomposition of formic acid (150% acid stoichiometry). Four simulants were prepared based on the four possible combinations of the Al/Fe and Mn-Ca/Mg-Ni-Cr options. Preliminary simulant preparation work has already been documented. The four simulants were used for high and low acid testing. Eight planned experiments (GF26 to GF33) were completed to demonstrate the viability of the glycolic-formic flowsheet. Composition and physical property measurements were made on the SRAT product. Composition measurements were made on the condensate from the Mercury Water Wash Tank (MWWT), Formic Acid Vent Condenser (FAVC), ammonia scrubber and on SRAT samples pulled throughout the SRAT cycle. Updated values for formate loss and nitrite-tonitrate conversion were found that can be used in the acid calculations for future sludge matrix process simulations with the glycolic acid/formic acid

  14. Metabolism of glycolate in mitochondria of Euglena gracilis

    Difference spectra taken at -1960C were given to confirm that glycolate oxidation by Euglena mitochondria is linked to the electron transport system with the production of ATP. In feeding experiments with 1-14C-glycolate on E. gracilis cells having glycolate dehydrogenase only in mitochondria, greater parts of the taken-up radioactivity were excreted as 14CO2 and greater parts of the remaining were distributed to the amino acid and protein fractions, mainly as glycine and serine. Presence of ammonium decreased 14CO2 evolution and augmented incorporation and distribution to protein of label. Exhaustion of nitrogen source stopped glycolate uptake. Deficiency of nitrogen source repressed glycolate hydrogenase most extensively among the enzymes involved in the glycolate pathway. The mechanism of regulation of the glycolate metabolism by nitrogen source is discussed. (auth.)

  15. 聚乙二醇电解质溶液分次与单次口服肠道准备方案的清洁效果和耐受性比较%Cleanliness and Tolerance of Fractionated Dose and Single Dose Polyethylene Glycol Electrolyte Solution Bowel Preparation Regimens for Colonoscopy:A Comparative Study

    蒋淼; 田培营; 李欢庆; 卜淑蕊; 樊晓明

    2014-01-01

    Colonoscopy has been accepted as the standard method for evaluation of colon and rectum,its success rate depends on the quality of bowel preparation. Aims:To evaluate the cleanliness and tolerance of fractionated dose versus single dose polyethylene glycol electrolyte solution( PEG-ES) bowel preparation regimens for colonoscopy. Methods:A total of 427 consecutive asymptomatic individuals undergoing colorectal cancer screening were enrolled and randomly assigned into 2 groups. Subjects in group A drank 1. 5 L PEG-ES on the eve and 4 hours before colonoscopy, respectively;subjects in group B received a single dose of 3 L PEG-ES 5 hours before colonoscopy. Score and degree of Boston bowel preparation scale(BBPS)and PEG-ES related adverse effects of the two groups were assessed and compared. Results:There were no significant differences in gender,age and cecal insertion rate between group A and group B(P ﹥ 0. 05). Score of BBPS was significantly higher in group A than in group B(P ﹤0. 01). Both regimens met the requirement of conventional colonoscopy,however,the cleanliness of colon was graded as excellent in more subjects of group A( P ﹤ 0. 01),and less subjects of group A complained PEG-ES related nausea(P ﹤0. 05). Logistic regression analysis revealed that the PEG-ES drinking pattern was associated with cleanliness of colon and occurrence of nausea( P ﹤ 0. 05). Conclusions:Fractionated dose PEG-ES regimen provides a better colonic cleansing quality and tolerance for bowel preparation of colonoscopy,which is superior to that of single dose regimen.%背景:结肠镜检查是公认的结直肠检查的金标准,而良好的肠道准备是检查成功的前提条件。目的:评价聚乙二醇电解质溶液( PEG-ES)分次与单次口服作为结肠镜检查肠道准备方案的清洁效果和耐受性。方法:连续纳入427例进行结直肠癌筛查的无症状个体,随机分为A组和B组。A组于检查前夜和检查前4 h分别口服1

  16. Biocompatibility Evaluation of a New Hydrogel Dressing Based on Polyvinylpyrrolidone/Polyethylene Glycol

    Esmaeil Biazar; Ziba Roveimiab; Gholamreza Shahhosseini; Mohammadreza Khataminezhad; Mandana Zafari; Ali Majdi

    2012-01-01

    The composition of the dressings is based on polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), and agar. The electron beam irradiation technique has been used to prepare hydrogel wound dressings. The in vitro biocompatibility of the hydrogel was investigated by check samples (hydrocolloid Comfeel), antibacterial test (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia Coli k12), anti fungal test (Candida Albicans) and cytotoxicity test (Fibroblast L929...

  17. Quantum dot/glycol chitosan fluorescent nanoconjugates

    Mansur, Alexandra AP; Mansur, Herman S.

    2015-04-01

    In this study, novel carbohydrate-based nanoconjugates combining chemically modified chitosan with semiconductor quantum dots (QDs) were designed and synthesised via single-step aqueous route at room temperature. Glycol chitosan (G-CHI) was used as the capping ligand aiming to improve the water solubility of the nanoconjugates to produce stable and biocompatible colloidal systems. UV-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy were used to characterise the synthesis and the relative stability of biopolymer-capped semiconductor nanocrystals. The results clearly demonstrated that the glycol chitosan derivative was remarkably effective at nucleating and stabilising semiconductor CdS quantum dots in aqueous suspensions under acidic, neutral, and alkaline media with an average size of approximately 2.5 nm and a fluorescent activity in the visible range of the spectra.

  18. 复方聚乙二醇电解质散在小儿结肠造口关闭手术前肠道准备中的应用%Application of polyethylene glycol electrolyte powder compound for pediatric bowel preparation before colostomy closure

    邝云莎; 刘艳青; 刘秋菊

    2015-01-01

    Objective:To observe the effect of peros polyethylene glycol electrolyte powder compound for pediatric bowel preparation before colostomy clo-sure. Methods:60 cases before colostomy closure were randomly divided into control group and experimental group. The experimental group drunk the solu-tion 6 hours before the operation,while the control group got two times of intestinal lavage (12 hours and 1 hour before the operation) from the near - end of the colostomy mouth. Compared the cleanliness of the near - end of the colostomy mouth, obedience and untoward effect. Results:The experimental group got much better cleanliness (P < 0. 05) and further obedience (P < 0. 05) than control group. The experimental group came out 4 cases of oral difficulty, control group. With 11 cases of acute crying and action,among 11 cases,there were 3 cases of mucosal injury,1 case of operation delaying,1 case of emesis. Conclusion:The effect and obedience of drinking the solution before colostomy closure is satisfactory. However,minority got untoward effect such as oral diffi-culty,emesis. It is still need futher study.%目的::探讨复方聚乙二醇电解质散在小儿结肠造口关闭手术前肠道准备中的应用效果。方法:将60例结肠造口术后拟行造口关闭手术的患儿随机等分为试验组和对照组,试验组采用术晨(术前6 h)口服复方聚乙二醇电解质散溶液的方法进行肠道准备,对照组采用术前晚(术前12 h)、术晨(术前1~2 h)自结肠造口近端各回流洗肠1次的方法进行肠道准备,比较两组患儿造口近端肠道清洁度、依从性及不良反应发生情况。结果:试验组造口近端肠道清洁度明显优于对照组(P <0.05),依从性高于对照组(P <0.05)。试验组出现口服困难4例,其中2例出现恶心、呕吐;对照组出现剧烈哭闹、活动11例,其中因剧烈哭闹导致造口近端黏膜损伤出血3例,延期手术1例(大量

  19. Characterization of tetraethylene glycol passivated iron nanoparticles

    Nunes, Eloiza da Silva; Viali, Wesley Renato [Laboratório de Materiais Magnéticos e Coloides, Departamento de Físico-química, Instituto de Química, Universidade Estadual Paulista, Araraquara, SP 14801-970 (Brazil); Silva, Sebastião William da; Coaquira, José Antonio Huamaní; Garg, Vijayendra Kumar; Oliveira, Aderbal Carlos de [Instituto de Física, Núcleo de Física Aplicada, Universidade de Brasília, Brasília, DF 70910-900 (Brazil); Morais, Paulo César [Instituto de Física, Núcleo de Física Aplicada, Universidade de Brasília, Brasília, DF 70910-900 (Brazil); School of Automation, Huazhong University of Science and Technology, Wuhan 430074 (China); Jafelicci Júnior, Miguel, E-mail: jafeli@iq.unesp.br [Laboratório de Materiais Magnéticos e Coloides, Departamento de Físico-química, Instituto de Química, Universidade Estadual Paulista, Araraquara, SP 14801-970 (Brazil)

    2014-10-01

    Graphical abstract: - Highlights: • Metallic iron nanoparticles were passivated in tetraethylene glycol media. • Passivated nanoparticles presented pomegranate-like core@shell structure. • Passivation of metallic iron correlates with the tetraethylene glycol degradation. • Boron enriched metallic iron phase was more susceptible to oxidation. • The iron oxide shell was identified as Fe{sub 3}O{sub 4} with a mass fraction of 43:53 related to αFe. - Abstract: The present study describes the synthesis and characterization of iron@iron oxide nanoparticles produced by passivation of metallic iron in tetraethylene glycol media. Structural and chemical characterizations were performed using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Mössbauer spectroscopy. Pomegranate-like core@shell nanoparticulate material in the size range of 90–120 nm was obtained. According to quantitative phase analysis using Rietveld structure refinement the synthesized iron oxide was identified as magnetite (Fe{sub 3}O{sub 4}) whereas the iron to magnetite mass fractions was found to be 47:53. These findings are in good agreement with the data obtained from Mössbauer and thermal gravimetric analysis (TGA). The XPS data revealed the presence of a surface organic layer with higher hydrocarbon content, possibly due to the tetraethylene glycol thermal degradation correlated with iron oxidation. The room-temperature (300 K) saturation magnetization measured for the as-synthesized iron and for the iron–iron oxide were 145 emu g{sup −1} and 131 emu g{sup −1}, respectively. The measured saturation magnetizations are in good agreement with data obtained from TEM, XRD and Mössbauer spectroscopy.

  20. Characterization of tetraethylene glycol passivated iron nanoparticles

    Graphical abstract: - Highlights: • Metallic iron nanoparticles were passivated in tetraethylene glycol media. • Passivated nanoparticles presented pomegranate-like core@shell structure. • Passivation of metallic iron correlates with the tetraethylene glycol degradation. • Boron enriched metallic iron phase was more susceptible to oxidation. • The iron oxide shell was identified as Fe3O4 with a mass fraction of 43:53 related to αFe. - Abstract: The present study describes the synthesis and characterization of iron@iron oxide nanoparticles produced by passivation of metallic iron in tetraethylene glycol media. Structural and chemical characterizations were performed using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Mössbauer spectroscopy. Pomegranate-like core@shell nanoparticulate material in the size range of 90–120 nm was obtained. According to quantitative phase analysis using Rietveld structure refinement the synthesized iron oxide was identified as magnetite (Fe3O4) whereas the iron to magnetite mass fractions was found to be 47:53. These findings are in good agreement with the data obtained from Mössbauer and thermal gravimetric analysis (TGA). The XPS data revealed the presence of a surface organic layer with higher hydrocarbon content, possibly due to the tetraethylene glycol thermal degradation correlated with iron oxidation. The room-temperature (300 K) saturation magnetization measured for the as-synthesized iron and for the iron–iron oxide were 145 emu g−1 and 131 emu g−1, respectively. The measured saturation magnetizations are in good agreement with data obtained from TEM, XRD and Mössbauer spectroscopy

  1. Quantum dot/glycol chitosan fluorescent nanoconjugates

    Mansur, Alexandra AP; Mansur, Herman S.

    2015-01-01

    In this study, novel carbohydrate-based nanoconjugates combining chemically modified chitosan with semiconductor quantum dots (QDs) were designed and synthesised via single-step aqueous route at room temperature. Glycol chitosan (G-CHI) was used as the capping ligand aiming to improve the water solubility of the nanoconjugates to produce stable and biocompatible colloidal systems. UV-visible (UV–vis) spectroscopy, photoluminescence (PL) spectroscopy, and Fourier transform infrared (FTIR) spec...

  2. Poly(ethylene glycol) interactions with proteins

    Hašek, Jindřich

    2006-01-01

    Roč. 2, č. 23 (2006), s. 613-618. ISSN 0044-2968. [European Powder Diffraction Conference /9./. Prague, 02.09.2004-05.09.2004] R&D Projects: GA ČR(CZ) GA204/02/0843 Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(ethylene glycol) * PEO * protein-polymer interaction Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.897, year: 2006

  3. Hydration of polyethylene glycol-grafted liposomes.

    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...

  4. Transport Selectivity of a Diethylene Glycol Dimethacrylate-Based Thymine-imprinted Polymeric Membrane over a Cellulose Support for Nucleic Acid Bases

    QU Xiang-Jin; CHEN Chang-Bao; ZHOU Jie; WU Chun-Hui

    2007-01-01

    The binding mechanism between 9-vinyladenine and pyrimidine base thymine in methanol was studied with UV-visible spectrophotometric method. Based on this study, using thymine as a template molecule, 9-vinyladenine as a novel functional monomer and diethylene glycol dimethacrylate as a new cross-linker, a specific diethylene glycol dimethacrylate-based molecularly imprinted polymeric membrane was prepared over a cellulose support.Then, the resultantly polymeric membrane morphologies were visualized with scanning electron microscopy and its permselectivity was examined using thymine, uracil, cytosine, adenine and guanine as substrates. This result showed that the imprinting polymeric membrane prepared with diethylene glycol dimethacrylate exhibited higher transport capacity for the template molecule thymine and its optimal analog uracil than other nucleic acid bases. The membrane also took on higher permselectivity than the imprinted membrane made with ethylene glycol dimethacrylate as a cross-linker. When a mixture including five nucleic acid bases thymine, uracil, cytosine, adenine and guanine passed through the diethylene glycol dimethacrylate-based thymine-imprinted polymeric membrane,recognition of the membrane for the template molecule thymine and its optimal analog uracil was demonstrated. It was predicted that the molecularly imprinted membrane prepared with diethylene glycol dimethacrylate as cross-linker might be applicable to thymine assay of absolute hydrolysates of DNA or uracil assay of absolute hydrolysates of RNA in biological samples because of its high selectivity for the template molecule thymine and its optimal analog uracil.

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

    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.

  6. Thermodynamics of solvation in propylene glycol and methyl cellosolve

    Highlights: • Experimental values of limiting activity coefficients in propylene glycol and methyl cellosolve are reported. • Gibbs free energy versus enthalpy of solvation plots show the presence of the solvophobic effects in studied solutions. • The solvophobic effect in propylene glycol is as strong as in methanol. • The solvophobic effect in methyl cellosolve is rather weak and can be compared to that in butanol. - Abstract: Limiting activity coefficients of low-polar substances: aliphatic and aromatic hydrocarbons, including alkanes, cycloalkanes, alkylbenzenes, and halobenzenes in two solvents, propylene glycol and methyl cellosolve, were measured at temperature T = 298.15 K using gas chromatographic headspace analysis technique. The Gibbs free energies of solvation were calculated from these data and analyzed together with the enthalpies of solvation for the same systems. It was shown that the Gibbs free energies of solvation in propylene glycol are significantly lower than in its homologue ethylene glycol, and in methyl cellosolve they are lower than in propylene glycol. This difference is mainly due to the solvophobic effect, which strength is decreasing in the same order: ethylene glycol > propylene glycol > methyl cellosolve. The contribution of the solvophobic effect into the Gibbs free energies of solvation can be determined using a Gibbs free energy versus enthalpy of solvation plot. This contribution is shown to grow up linearly with the molecular volume of a solute in propylene glycol and methyl cellosolve, as well as in ethylene glycol and in monohydric alcohols

  7. Thermal transport properties of ethylene glycol/N-methylformamide binary mixture based CuO nanofluid

    Gopalakrishnan, M.; Kiruba, R.; Jeevaraj, A. Kingson Solomon

    2015-06-01

    In this present investigation, we have synthesized copper oxide nanoparticles by solvothermal method and analyzed their rheological behavior and thermal conductivity properties in binary base fluids (Ethylene Glycol+N-Methylformamide) and CuO binary nanofluid at different temperature. The crystalline nature and morphological properties of prepared CuO nanoparticles were characterized using XRD and SEM analysis respectively. The influence of CuO nanoparticles increases the thermal conductivity of binary base fluids. The results suggested that prepared binary nanofluids can be applicable in heat transfer.

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

    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.

  9. Absorption of some glycol ethers through human skin in vitro.

    Dugard, P H; M. Walker; Mawdsley, S J; Scott, R.C.

    1984-01-01

    To assist evaluation of the hazards of skin contact with selected undiluted glycol ethers, their absorption across isolated human abdominal epidermis was measured in vitro. Epidermal membranes were set up in glass diffusion cells and, following an initial determination of permeability to tritiated water, excess undiluted glycol ether was applied to the outer surface for 8 hr. The appearance of glycol ether in an aqueous "receptor" phase bathing the underside of the epidermis was quantified by...

  10. Polyethylene glycols (PEG) and related structures

    Wenande, Emily; Kroigaard, Mogens; Mosbech, Holger; Garvey, Lene H

    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....

  11. Stabilization of Polyethylene Glycol in Archaeological Wood

    Mortensen, Martin Nordvig; Hvilsted, Søren

    2009-01-01

    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 skibsvragene. Kun i overfladen fandtes PEG med molekylvægte 4000, og det blev fastslået, at en såkaldt tailing (forårsaget af lave PEG molekylvægte (

  12. Lauroyl/palmitoyl glycol chitosan gels enhance skin delivery of magnesium ascorbyl phosphate.

    Wang, Po-Chun; Huang, Yan-Ling; Hou, Sheng-Shu; Chou, Chen-Hsi; Tsai, Jui-Chen

    2013-01-01

    Palmitoyl glycol chitosan (GCP) hydrogel has been reported as erodible controlled-release systems for the delivery of both hydrophilic and hydrophobic molecules. In this study we prepared lauroyl/palmitoyl glycol chitosan (GCL/GCP) in gel form and evaluated their application for skin delivery of the hydrophilic compound, magnesium ascorbyl phosphate (MAP), which is widely used in cosmetic formulations. Release of MAP from the polymer gels was significantly decreased with increasing concentration of GCL/GCP in the formulations in comparison with glycol chitosan (GC). In both aqueous and 10% ethanol vehicles, MAP flux was increased 1.58- to 3.96-fold of 1% GC from 1% GCL/GCP. Increase in MAP flux was correlated to the increase in GCL/GCP concentration prepared in 10% ethanol vehicle. GCL/GCP, in either water or 10% ethanol vehicles, increased the skin penetration and skin deposition of MAP in comparison with GC, hydroxypropylmethylcellulose, and carbopol, while sustaining its release from the polymer gels. Both the enhancement in skin penetration/deposition and sustained release of MAP were depended on polymer concentration. Also, with increase in polymer concentration, epidermal to dermal drug deposition ratio tended to increase, which will be beneficial to its activity in the epidermis, such as inhibition of tyrosinase and protection from UV damage. These data suggested both GCL and GCP can be applied as delivery vehicles to improve percutaneous absorption of MAP. PMID:23931090

  13. Transport properties of nano manganese ferrite-propylene glycol dispersion (nanofluids): new observations and discussion

    Aishwarya, V.; Suganthi, K. S.; Rajan, K. S., E-mail: ksrajan@chem.sastra.edu [SASTRA University, Centre for Nanotechnology and Advanced Biomaterials (CeNTAB), School of Chemical and Biotechnology (India)

    2013-07-15

    Experiments were conducted on the preparation of manganese ferrite nanoparticles and their surface modification for dispersion in propylene glycol. The appropriate concentrations of ferrous sulphate and manganese sulphate (precursors) for synthesis of uniform Mn{sub 0.43}Fe{sub 2.57}O{sub 4} nanoparticles (size range {approx}20-25 nm) were found to be 0.05 and 0.025 M, respectively. These nanoparticles were coated with citric acid and dispersed in propylene glycol for the preparation of nanofluids. The effects of temperature and nanoparticle concentration on nanofluid viscosity and thermal conductivity have been studied. Our study on the influence of nanoparticle concentration on viscosity reveals the existence of a viscosity minimum for 0.25 vol% of citric acid-modified Mn{sub 0.43}Fe{sub 2.57}O{sub 4}-propylene glycol nanofluid. A thermal conductivity enhancement of 68 % was observed for 2 vol% nanofluid. Correlating viscosity and thermal conductivity measurements, particle clustering seems to be the major factor responsible for thermal conductivity enhancement.

  14. Thermal performance of ethylene glycol based nanofluids in an electronic heat sink.

    Selvakumar, P; Suresh, S

    2014-03-01

    Heat transfer in electronic devices such as micro processors and power converters is much essential to keep these devices cool for the better functioning of the systems. Air cooled heat sinks are not able to remove the high heat flux produced by the today's electronic components. Liquids work better than air in removing heat. Thermal conductivity which is the most essential property of any heat transfer fluid can be enhanced by adding nano scale solid particles which possess higher thermal conductivity than the liquids. In this work the convective heat transfer and pressure drop characteristics of the water/ethylene glycol mixture based nanofluids consisting of Al2O3, CuO nanoparticles with a volume concentration of 0.1% are studied experimentally in a rectangular channel heat sink. The nano particles are characterized using Scanning Electron Microscope and the nannofluids are prepared by using an ultrasonic vibrator and Sodium Lauryl Salt surfactant. The experimental results showed that nanofluids of 0.1% volume concentration give higher convective heat transfer coefficient values than the plain water/ethylene glycol mixture which is prepared in the volume ratio of 70:30. There is no much penalty in the pressure drop values due to the inclusion of nano particles in the water/ethylene glycol mixture. PMID:24745228

  15. Surface modification of polydimethylsiloxane with photo-grafted poly(ethylene glycol) for micropatterned protein adsorption and cell adhesion.

    Sugiura, Shinji; Edahiro, Jun-ichi; Sumaru, Kimio; Kanamori, Toshiyuki

    2008-06-01

    In this study, we applied photo-induced graft polymerization to micropatterned surface modification of polydimethylsiloxane (PDMS) with poly(ethylene glycol). Two types of monomers, polyethylene glycol monoacrylate (PEGMA) and polyethylene glycol diacrylate (PEGDA), were tested for surface modification of PDMS. Changes in the surface hydrophilicity and surface element composition were characterized by contact angle measurement and electron spectroscopy for chemical analysis. The PEGMA-grafted PDMS surfaces gradually lost their hydrophilicity within two weeks. In contrast, the PEGDA-grafted PDMS surface maintained stable hydrophilic characteristics for more than two months. Micropatterned protein adsorption and micropatterned cell adhesion were successfully demonstrated using PEGDA-micropatterned PDMS surfaces, which were prepared by photo-induced graft polymerization using photomasks. The PEGDA-grafted PDMS exhibited useful characteristics for microfluidic devices (e.g. hydrophilicity, low protein adsorption, and low cell attachment). The technique presented in this study will be useful for surface modification of various research tools and devices. PMID:18242961

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

    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.

  17. Experimental investigation in thermal conductivity of CuO and ethylene glycol nanofluid in serpentine shaped microchannel

    Mr. A. Sivakumar

    2014-07-01

    Full Text Available This research work investigates the thermal conductivity and viscosity of copper oxide nanoparticles in ethylene glycol. The copper oxide was dispersed in ethylene glycol using a sonicator. The nanofluid suspension were prepared for different concentration upto 0.3%. The heat transfer principle states that maximum heat transfer is achieved in microchannels with minimum pressure drop across it. The increase in viscosity was about four times of that predicted by the Einstein law of viscosity. In this research work the experimental and numerical investigation for the improved heat transfer characteristics of serpentine shaped microchannel heat sink using CuO/ ethylene glycol nanofluid is done. The fluid flow characteristics is also analyzed for the serpentine shaped micrchannel. The experimental results of the heat transfer using CuO/ ethylene glycol nanofluid is compared with the numerical values. The results in this work suggest that the best heat transfer enhancement can be obtained compared with base fluid by using a system with an CuO – ethylene glycol nanofluid-cooled micro channel with serpentine shaped fluid flow.

  18. Glycol-Substitute for High Power RF Water Loads

    Ebert, Michael

    2005-01-01

    In water loads for high power rf applications, power is dissipated directly into the coolant. Loads for frequencies below approx. 1GHz are ordinarily using an ethylene glycol-water mixture as coolant. The rf systems at DESY utilize about 100 glycol water loads with powers ranging up to 600kW. Due to the increased ecological awareness, the use of glycol is now considered to be problematic. In EU it is forbidden to discharge glycol into the waste water system. In case of cooling system leakages one has to make sure that no glycol is lost. Since it is nearly impossible to avoid any glycol loss in large rf systems, a glycol-substitute was searched for and found. The found sodium-molybdate based substitute is actually a additive for corrosion protection in water systems. Sodium-molybdate is ecologically harmless; for instance, it is also used as fertilizer in agriculture. A homoeopathic dose of 0.4% mixed into deionised water gives better rf absorption characteristics than a 30% glycol mixture. The rf coolant feat...

  19. Application of simplified PC-SAFT to glycol ethers

    Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2012-01-01

    The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2...

  20. Congenital malformations and maternal occupational exposure to glycol ethers

    Cordier, S; Bergeret, A; Goujard, J; Ha, MC; Ayme, S; Calzolari, E; DeWalle, HEK; KnillJones, R; Candela, S; Dale, [No Value; Dananche, B; deVigan, C; Fevotte, J; Kiel, G; Mandereau, L

    1997-01-01

    Glycol ethers are found in a wide range of domestic and industrial products, many of which are used in women's work environments. Motivated by concern about their potential reproductive toxicity, we have evaluated the risk of congenital malformations related to glycol ether exposure during preg nanc

  1. Glycolic acid synthesis during dark glucose U14C metabolism, in French Bean and Maize leaves

    Serine, glycerate and glycolate are among the first radioactive compounds when French Bean and Maize leaves are fed with glucose U14C. Failing to detect radioactive glycine suggests that glycolate so synthesized is unavailable for the photorespiration glycolate pool

  2. Poly(ethylene glycol)/carbon quantum dot composite solid films exhibiting intense and tunable blue–red emission

    Highlights: • Poly(ethylene glycol)/carbon quantum dots (PEG/CQDs) composite solid films exhibiting strong and tunable blue–red emission were prepared. Successful preparation of tunable emitting CQDs solid films can extend the application of carbon quantum dots in photoelectric devices. • The mechanism of the tunable emission from the PEG/CQDs composite solid films was discussed. • On the basis of the characteristics of the PL from solid films in this work, the complex PL origins of CQDs were further defined. The PL mechanism provides insights into the fluorescence mechanism of CQDs and may promotes their applications. • Poly(ethylene glycol); carbon quantum dots; Strong and tunable blue-red emission; The fluorescent quantum yield of 12.6%. - Abstract: Although carbon quantum dots (CQDs) possess excellent luminescence properties, it is a challenge to apply water-soluble CQDs to tunable luminescent devices. Herein, quaternary CQDs are incorporated into poly(ethylene glycol) to produce poly(ethylene glycol)/CQD composite solid films which exhibit strong and tunable blue–red emission. The fluorescent quantum yield reaches 12.6% which is comparable to that of many liquid CQDs and the photoluminescence characteristics are determined to elucidate the fluorescence mechanism. The CQD solid films with tunable optical properties bode well for photoelectric devices especially displays

  3. Millimetre wave rotational spectrum of glycolic acid

    Kisiel, Zbigniew; Pszczółkowski, Lech; Białkowska-Jaworska, Ewa; Charnley, Steven B.

    2016-03-01

    The pure rotational spectrum of glycolic acid, CH2OHCOOH, was studied in the region 115-318 GHz. For the most stable SSC conformer, transitions in all vibrational states up to 400 cm-1 have been measured and their analysis is reported. The data sets for the ground state, v21 = 1 , and v21 = 2 have been considerably extended. Immediately higher in vibrational energy are two triads of interacting vibrational states and their rotational transitions have been assigned and successfully fitted with coupled Hamiltonians accounting for Fermi and Coriolis resonances. The derived energy level spacings establish that the vibrational frequency of the ν21 mode is close to 100 cm-1. The existence of the less stable AAT conformer in the near 50 °C sample used in our experiment was also confirmed and additional transitions have been measured.

  4. Water potential of aqueous polyethylene glycol.

    Steuter, A A

    1981-01-01

    Water potential (Psiomega) values were determined for aqueous colloids of four molecular sizes of polyethylene glycol (PEG) using freezing-point depression and vapor-pressure deficit methods. A significant third-order interaction exists between the method used to determine Psiomega, PEG molecular size, and concentration. At low PEG concentrations, freezing-point depression measurements result in higher (less negative) values for Psiomega than do vapor-pressure deficit measurements. The reverse is true at high concentrations. PEG in water does not behave according to van't Hoff's law. Psiomega is related to molality for a given PEG but not linearly. Moreover, Psiomega varies with the molecular size of the PEG. It is suggested that the Psiomega of PEG in water may be controlled primarily by the matric forces of ethylene oxide subunits of the PEG polymer. The term matricum is proposed for PEG in soil-plant-water relation studies. PMID:16661635

  5. Ethylene glycol reduced graphene oxide/polypyrrole composite for supercapacitor

    Highlights: ► A novel EG-RGO/PPy composite for supercapacitor application is well constructed. ► The well-soluble GO was dispersed in aqueous polymerisable aniline monomer solution to form stable GO/PPy structure. ► The EG reduced RGO/PPy can retain the PPy conductive conjugative frameworks. ► The EG-RGO/PPy electrode exhibits superior electrochemical capability as supercapacitor electrode. -- Abstract: A promising supercapacitor material based on graphene/polypyrrole (PPy) has been successfully synthesized via in situ oxidation polymerization of pyrrole monomers in aqueous graphene oxide (GO) solutions, followed by chemical reduction using ethylene glycol (EG). Unlike the commonly employed hydrazine reduction, the moderate EG reductant does not destruct the PPy conjugative structures, thus facilitating utilization of the electroactive conductive polymer. The morphologies and the structures of the as-prepared materials are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra, and Fourier transform infrared spectroscopy (FTIR). And the electrochemical performance of the fabricated electrodes was evaluated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The EG-RGO/PPy electrode shows large specific capacitance, high rate performance, and good charge–discharge stability as well. The excellent electrochemical capability is mainly accounted for the sound composite construction that improves the effective utilization of electroactive PPy component, accelerates shuttling the charged carriers, and alleviates the swelling/shrinkage of polymer chains

  6. Validation of an analytical methodology for the determination of diethylene glycol and ethylene glycol as impurities in glycerin and propylene glycol

    A methodology for the quantification of diethylene glycol (DEG) and the ethylene glycol (EG) impurities by gas Chromatography with flame ionization detector in glycerol and propylene glycol samples was developed and validated. It was selected dimethyl sulphoxide as internal standard. It was used hydrogen as carrier and auxiliary gas. The temperature program was 100°C holding one minute, then ramp to rate of 7.5°C/ min up to 200 °C. A Restek 624 column was used, with a flow in column of 4.20 ml/ min. Temperatures of the injector and detector were set at 220°C and 250 °C, respectively. The linearity was determined at 25-75 ?μg/ml as interval of concentrations for both impurities with correlation coefficients larger than 0.999. Detection Limits were settled down in 0.0350 μ?g/ml to the diethylene glycol, and 0.0572 μg/ml to ethylene glycol, while the quantitation limits were 0.1160 μ?g/ml to DEG and 0.1897 μg/ml to the EG. The recoveries were 99.98 % and 100.00 %, respectively; with RSD % 1.18 % to DEG, and 0.60 % to the EG. The obtained results demonstrated that the methodology was linear, accurate, robustness, sensitive and selective to be used in the determination of both impurities in the quality control of the glycerol and propylene glycol as raw materials

  7. Hydrolytically and reductively degradable high-molecular-weight poly(ethylene glycol)s

    Braunová, Alena; Pechar, Michal; Laga, Richard; Ulbrich, Karel

    2007-01-01

    Roč. 208, č. 24 (2007), s. 2642-2653. ISSN 1022-1352 R&D Projects: GA AV ČR KAN200200651; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable * drug delivery systems * gene delivery vectors * poly(ethylene glycol) Subject RIV: CE - Biochemistry Impact factor: 2.046, year: 2007

  8. The localization of glycollate-pathway enzymes in Euglena.

    Collins, N; Merrett, M J

    1975-05-01

    Isolation of organelles from broken-cell suspensions of phototrophically grown Euglena gracilis Klebs was achieved by isopycnic centrifugation on sucrose gradients. 2. Equilibrium densities of 1.23g/cm3 for peroxisome-like particles, 1.22g/cm3 for mitochondria and 1.17g/cm3 for chloroplasts were recorded. 3. The enzymes glycollate dehydrogenase, glutamate-glyoxylate aminotransferase, serineglyoxylate aminotransferase, aspartate-alpha-oxoglutarate aminotransferase, hydroxy pyruvate reductase and malate dehydrogenase were present in peroxisome-like particles. 4. Unlike higher plants glycollate dehydrogenase and glutamate-glyoxylate aminotransferase were present in the mitochondria of Euglena. 5. Rates of glycollate and D-lactate oxidation were additive in the mitochondria, and, although glycollate dehydrogenase was inhibited by cyanide, D-lactate dehydrogenase activity was unaffected. 6. Glycollate oxidation was linked to O2 uptake in mitochondria but not in peroxisome-like particles. This glycollate-dependent O2 uptake was inhibited by antimycin A or cyanide. 7. The physiological significance of glycollate metabolism in Euglena mitochondria is discussed, with special reference to its role in photorespiration in algae. PMID:1156408

  9. Alternating polyesteramides based on 1,4-butylene terephthalamide: 4. Alternating polyetheresteramides based on glycols (4NTglycol)

    Serrano, P.J.M.; Gaymans, R.J.

    1998-01-01

    Polyetheresteramides (PEEAs) have been synthesised in the melt from 1,4-butylene terephthalamide and ethylene or propylene glycols. The ethylene glycols were ethylenediol, diethylene glycol, triethylene glycol and tetraethylene glycol. The propylene glycols were 1,3-propanediol and the mixtures of 1

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

    A poly(ethylene glycol)-b-poly[2-(N,N-dimethylamino)ethyl 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. (topical review)

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

    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.

  12. Assessment of a method for measuring serum thyroxine by radioimmunoassay, with use of polyethylene glycol precipitation

    We assessed the efficacy of a new thyroxine radioimmunoassay kit (Abbott) in which polyethylene glycol is used to separate bound from free hormone. Mean serum thyroxine was 88 +- 15 (+-SD) μg/liter for 96 normal persons. Results for hypothyroid and hyperthyroid persons were clearly separated from those for normal individuals. Women taking oral contraceptive preparations showed variable increases in their serum thyroxine values. The coefficient of variation ranged from 1 to 3% within assay and from 5.4 to 11% among different assays. Excellent parallelism was demonstrated between thyroxine values estimated by this method and those obtained either by competitive protein binding or by a separate radioimmunoassay for the hormone

  13. Preparation and characterization of mesoporous tetragonal sulfated zirconia

    Chun Xia He; Bin Yue; Ji Fang Cheng; Wei Ming Hua; Ying Hong Yue; He Yong He

    2009-01-01

    Mesoporous tetragonal sulfated zirconia with high surface area and narrow pore-size distribution was prepared using Zr(O-nPr)4 as zirconium precursor, sulfuric acid as sulfur source and triblock copolymer poly(ethylene glycol)-poly(propylene glycol)poly(ethylene glycol) (P123) as the template. The samples were characterized by X-ray diffraction, N2 sorption, TEM, and NH3TPD. A phase transformation from monoclinic sulfated zirconia to tetragonal sulfated zirconia is observed. The product shows strong acidity.

  14. Paclitaxel-incorporated nanoparticles using block copolymers composed of poly(ethylene glycol)/poly(3-hydroxyoctanoate)

    Kim, Hyun Yul; Ryu, Je Ho; Chu, Chong Woo; Son, Gyung Mo; Jeong, Young-IL; Kwak, Tae-Won; Kim, Do Hyung; Chung, Chung-Wook; Rhee, Young Ha; Kang, Dae Hwan; Kim, Hyung Wook

    2014-01-01

    Block copolymers composed of poly(3-hydroxyoctanoate) (PHO) and methoxy poly(ethylene glycol) (PEG) were synthesized to prepare paclitaxel-incorporated nanoparticle for antitumor drug delivery. In a 1H-NMR study, chemical structures of PHO/PEG block copolymers were confirmed and their molecular weight (M.W.) was analyzed with gel permeation chromatography (GPC). Paclitaxel as a model anticancer drug was incorporated into the nanoparticles of PHO/PEG block copolymer. They have spherical shapes...

  15. In Vitro and In Vivo Study of Poly(ethylene glycol) Conjugated Ibuprofen to Extend the Duration of Action

    Nayak, Anjali; Jain, Anurekha

    2011-01-01

    Ibuprofen–polyethylene glycol (PEG) conjugates (PEG-Ibu) were prepared and their potential as a prolonged release system was investigated. Two PEG-Ibu conjugates were synthesized from Ibuprofen and PEG with two different molecular weights by esterification in the presence of DCC and DMAP. The PEG-Ibu conjugates were characterized by FT-IR, 1H NMR, Mass spectroscopy and DSC analysis. The solubility study in aqueous system showed an increase in solubility of conjugates. The dissolution / hydrol...

  16. Synthesis and characterization of CdSe/ZnS quantum dots conjugated with poly (ethylene glycol) diamine

    Bharti, Shivani; Tripathi, S. K., E-mail: surya@pu.ac.in [Department of Physics, Centre of Advanced Study in Physics Panjab University, Chandigarh-160014 (India); Kaur, Gurvir [Sant Longowal Institute of Engineering & Technology, Longowal, Sangrur (India); Gupta, Shikha [Goswami Ganesh Dutta Sanatan Dharma College, Chandigarh (India)

    2015-08-28

    Bio-functionalization or surface modification is an important technique to obtain biocompatibility in semiconductor nanoparticles for biomedical applications. In this study semiconductor core/shell quantum dots of CdSe/ZnS have been prepared by chemical reduction method and then further PEGylated using Poly(ethylene glycol) diamine of M{sub w} 2000. They were characterized by UV-vis spectroscopy & Fourier transform infrared spectroscopy. The results reveals the successful PEGylation of CdSe/ZnS quantum dots.

  17. Synthesis and characterization of CdSe/ZnS quantum dots conjugated with poly (ethylene glycol) diamine

    Bio-functionalization or surface modification is an important technique to obtain biocompatibility in semiconductor nanoparticles for biomedical applications. In this study semiconductor core/shell quantum dots of CdSe/ZnS have been prepared by chemical reduction method and then further PEGylated using Poly(ethylene glycol) diamine of Mw 2000. They were characterized by UV-vis spectroscopy & Fourier transform infrared spectroscopy. The results reveals the successful PEGylation of CdSe/ZnS quantum dots

  18. Magnetic fluids stabilized by polypropylene glycol

    Lebedev, A.V., E-mail: lav@icmm.r [Institute of Continuous Media Mechanics, UB RAS, Academic Korolev Str. 1, Perm 614013 (Russian Federation); Lysenko, S.N. [Institute of Technical Chemistry, UB RAS, Academic Korolev Str. 3, Perm 614013 (Russian Federation)

    2011-05-15

    A series of samples of magnetic fluids stabilized with low-molecular weight polypropylene glycol (PPG) of different molecular masses were synthesized. The use of PPG allowed the maximum extension of the carrier fluid range to include ethyl- and butyl-acetate, ethanol, butanol, acetone, carbon tetrachloride, toluene, kerosene and PPG itself. Magnetic and rheological properties of the samples were investigated. Based on the results of investigation it has been concluded that magnetic nanoparticles are covered by a monolayer of surfactant molecules. At low temperatures the propanol-based sample preserves fluidity up to -115 {sup o}C. Measurement of critical temperatures of other base fluids showed that alcohols are the best carrier medium. Coagulation stability of the ethanol-based ferrocolloid with respect to water and kerosene was explored. It has been found that kerosene, whose fraction by weight exceeds 22.5%, does not mix with the colloid. This effect can be used to produce magneto-controllable extractors of ethyl alcohol. Under the action of water the colloid coagulates, which allows one to substitute the carrier fluid and to separate the colloid into fractions. - Research highlights: PPG stabilizes the magnetic particles in the polar and non-polar media. The minimum operating temperature reaches -115 {sup o}C. Alcohols are the best environment for PPG-stabilized particles. PPG magnetic fluids can be used as magnetic extractors of alcohol. PPG MF can be divided into fractions by partial coagulation with water.

  19. Measurement of diffusion coefficient of propylene glycol in skin tissue

    Genin, Vadim D.; Bashkatov, Alexey N.; Genina, Elina A.; Tuchin, Valery V.

    2015-03-01

    Optical clearing of the rat skin under the action of propylene glycol was studied ex vivo. It was found that collimated transmittance of skin samples increased, whereas weight and thickness of the samples decreased during propylene glycol penetration in skin tissue. A mechanism of the optical clearing under the action of propylene glycol is discussed. Diffusion coefficient of propylene glycol in skin tissue ex vivo has been estimated as (1.35±0.95)×10-7 cm2/s with the taking into account of kinetics of both weight and thickness of skin samples. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  20. Selected polyethylene glycols as DOP substitutes. Addendum 1

    The recommendation is made that Polyethylene glycol (PEG) 400 be considered as a substitute for DOP in aerosol generators producing a polydisperse distribution for testing the integrity of filters and for testing respirator fit. Further, the recommendation is made that pentaethylene glycol (PTAEG) and possibly hexaethylene glycol be considered as a substitute for DOP in aerosol generators thermally producing monodisperse aerosol for quality acceptance tests according tu US federal specifications and standards. The toxicology data base available on the polyethylene glycol family of chemical compounds is discussed and the conclusion is drawn that the probability of approval and acceptance as a non-hazardous substance in the filter and filter media test role is high. Data and analysis supporting PTAEG performance equivalent to DOP in the filter and filter media test role are given or referenced. Cost and availability of the substitute materials is discussed. Conclusions based on the present data and information are given and recommendations for further work are made

  1. Molar heat capacities of some aqueous (2-amino-2-hydroxymethyl-1,3-propanediol + glycol) systems

    Highlights: ► The molar heat capacities for several aqueous (2-amino-2-hydroxymethyl-1,3-propanediol + glycol) systems were measured. ► The glycols considered were ethylene glycols and propylene glycols. ► The temperature studied was (30 to 70) °C. ► The measured data were reported as functions of temperature and composition. ► The measured data were represented satisfactorily by the applied correlations. - Abstract: A new set of molar heat capacity data for aqueous {2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) + glycol} at (30 to 80) °C and different concentrations (4% to 16% by weight TRIS or 56% to 44% by weight water, in a fixed amount of glycol – 40% by weight) were gathered via reliable measurement method and are presented in this report. The glycols considered were diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (T4EG), propylene glycol (PG), dipropylene glycol (DPG), and tripropylene glycol (TPG). The 198 data points gathered fit the equation, Cp = Cp,a + B1m + B2m2 + B3m3, where Cp and Cp,a are the molar heat capacities of the (TRIS + glycol + water) and (water + glycol) systems, respectively, Bi the temperature-dependent parameters, and m the mole TRIS per kilogram (glycol + water). The overall average absolute deviation (AAD) of the experimental data from the corresponding values calculated from the correlation equation was 0.07%.

  2. Effect of monobutylether ethylene glycol on Mg/Al layered double hydroxide: a physicochemical and conductivity study

    Paulo, Maria Joao [Materiaux et Telecommunications, Institut National de la Rechercher Scientifique - Energie (Canada); Matos, Bruno Ribeiro de [Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP (Brazil); Ntais, Spyridon [Materiaux et Telecommunications, Institut National de la Rechercher Scientifique - Energie (Canada); Coral Fonseca, Fabio [Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP (Brazil); Tavares, Ana C., E-mail: tavares@emt.inrs.ca [Materiaux et Telecommunications, Institut National de la Rechercher Scientifique - Energie (Canada)

    2013-02-15

    Mg-Al hydrotalcite-like compounds with OH{sup -} ions intercalated in the gallery and modified with monobutylether ethylene glycol (mbeeg) were prepared from Mg{sub 6}Al{sub 2}(CO{sub 3})(OH){sub 16}{center_dot}4H{sub 2}O by the reconstruction method. The effect of the ethylene glycol, a moderate surfactant, on the textural properties and on the vapor water sorption of the layered double hydroxides was investigated by transmission electron microscopy and nitrogen and water sorption techniques. The ion conductivity of the samples was measured at 98 % RH up to 180 Degree-Sign C. The compounds are formed by nanoplatelets with a lateral size inferior to 20 nm. The addition of the ethylene glycol was found to increase the specific surface area, total pore volume, and water sorption capacity of the Mg-Al layered double hydroxide. However, it also decreased the average pore diameter, and the ion conductivity of the ethylene glycol modified layered double hydroxide was lower than expected based on the samples' specific surface area and water content.

  3. Glycolic acid peel therapy – a current review

    Sharad, Jaishree

    2013-01-01

    Jaishree Sharad Skinfiniti Aesthetic Skin and Laser Clinic, Mumbai, India Abstract: Chemical peels have been time-tested and are here to stay. Alpha-hydroxy peels are highly popular in the dermatologist's arsenal of procedures. Glycolic acid peel is the most common alpha-hydroxy acid peel, also known as fruit peel. It is simple, inexpensive, and has no downtime. This review talks about various studies of glycolic acid peels for various indications, such as acne, acne scars, melasma, ...

  4. Glycolic acid peel therapy – a current review

    Sharad J

    2013-01-01

    Jaishree Sharad Skinfiniti Aesthetic Skin and Laser Clinic, Mumbai, India Abstract: Chemical peels have been time-tested and are here to stay. Alpha-hydroxy peels are highly popular in the dermatologist's arsenal of procedures. Glycolic acid peel is the most common alpha-hydroxy acid peel, also known as fruit peel. It is simple, inexpensive, and has no downtime. This review talks about various studies of glycolic acid peels for various indications, such as acne, acne scars, melasma, posti...

  5. Material compatibility evaluation for DWPF nitric-glycolic acid-literature review

    Mickalonis, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Skidmore, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2013-06-01

    Glycolic acid is being evaluated as an alternative for formic and nitric acid in the DWPF flowsheet. Demonstration testing and modeling for this new flowsheet has shown that glycolic acid and glycolate has a potential to remain in certain streams generated during the production of the nuclear waste glass. A literature review was conducted to assess the impact of glycolic acid on the corrosion of the materials of construction for the DWPF facility as well as facilities downstream which may have residual glycolic acid and glycolates present. The literature data was limited to solutions containing principally glycolic acid.

  6. An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures

    Lee, Jason S.; Ray, Richard I.; Lowe, Kristine L.; Jones-Meehan, Joanne; Little, Brenda J.

    2003-01-01

    Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures.

  7. Mitochondrial glycolate oxidation contributes to photorespiration in higher plants.

    Niessen, Markus; Thiruveedhi, Krishnaveni; Rosenkranz, Ruben; Kebeish, Rashad; Hirsch, Heinz-Josef; Kreuzaler, Fritz; Peterhänsel, Christoph

    2007-01-01

    The oxidation of glycolate to glyoxylate is an important reaction step in photorespiration. Land plants and charophycean green algae oxidize glycolate in the peroxisome using oxygen as a co-factor, whereas chlorophycean green algae use a mitochondrial glycolate dehydrogenase (GDH) with organic co-factors. Previous analyses revealed the existence of a GDH in the mitochondria of Arabidopsis thaliana (AtGDH). In this study, the contribution of AtGDH to photorespiration was characterized. Both RNA abundance and mitochondrial GDH activity were up-regulated under photorespiratory growth conditions. Labelling experiments indicated that glycolate oxidation in mitochondrial extracts is coupled to CO(2) release. This effect could be enhanced by adding co-factors for aminotransferases, but is inhibited by the addition of glycine. T-DNA insertion lines for AtGDH show a drastic reduction in mitochondrial GDH activity and CO(2) release from glycolate. Furthermore, photorespiration is reduced in these mutant lines compared with the wild type, as revealed by determination of the post-illumination CO(2) burst and the glycine/serine ratio under photorespiratory growth conditions. The data show that mitochondrial glycolate oxidation contributes to photorespiration in higher plants. This indicates the conservation of chlorophycean photorespiration in streptophytes despite the evolution of leaf-type peroxisomes. PMID:17595195

  8. A glycolate dehydrogenase in the mitochondria of Arabidopsis thaliana.

    Bari, Rafijul; Kebeish, Rashad; Kalamajka, Rainer; Rademacher, Thomas; Peterhänsel, Christoph

    2004-03-01

    The fixation of molecular O2 by the oxygenase activity of Rubisco leads to the formation of phosphoglycolate in the chloroplast that is further metabolized in the process of photorespiration. The initial step of this pathway is the oxidation of glycolate to glyoxylate. Whereas in higher plants this reaction takes place in peroxisomes and is dependent on oxygen as a co-factor, most algae oxidize glycolate in the mitochondria using organic co-factors. The identification and characterization of a novel glycolate dehydrogenase in Arabidopsis thaliana is reported here. The enzyme is dependent on organic co-factors and resembles algal glycolate dehydrogenases in its enzymatic properties. Mutants of E. coli incapable of glycolate oxidation can be complemented by overexpression of the Arabidopsis open reading frame. The corresponding RNA accumulates preferentially in illuminated leaves, but was also found in other tissues investigated. A fusion of the N-terminal part of the Arabidopsis glycolate dehydrogenase to red fluorescent protein accumulates in mitochondria when overexpressed in the homologous system. Based on these results it is proposed that the basic photorespiratory system of algae is conserved in higher plants. PMID:14966218

  9. Ethylene- and diethylene glycol metabolism, toxicity and treatment

    Each year numerous men and domestic animals suffer from ethylene glycol (EG) poisoning. The present approach to treating EG poisoning by administering ethanol is aimed at preventing the oxidation of EG to glycolate, the toxic mediator. When treatment is delayed or the amount of EG consumed is large, successful treatment is rarely obtained, since the concentration of glycolate becomes excessive. In an effort to develop a better approach to treating EG poisoning, studies were conducted to determine the feasibility of using pig liver glycolic acid oxidase (GAO) as a means of enzyme therapy in male rats receiving EG. Pig liver GAO was active in vitro in rat blood, oxidizing glycolate to glyoxylate. When injected intravenously into male rats, GAO had an approximate half-life of twenty five minutes and its elimination followed first order kinetics. Despite activity in vitro, native pig liver GAO did not display detectable activity in vivo. Diethylene glycol (DEG) when ingested also results in toxicity. The metabolism and toxicity of DEG was investigated in male Wistar rats using [14C]-DEG synthesized from [U-14C]-EG and ethylene oxide and purified by high performance liquid chromatography. (2-Hydroxyethoxy)acetic acid (HEAA) was identified as the major product of DEG oxidation. These results suggest that the treatment of DEG poisoning should follow the same regimen as treatment for EG poisoning

  10. Preparation of NiMgAI Layered Double Hydroxides and Hydrogen Production from Aqueous-Phase Reforming of Ethylene Glycol%镍镁铝水滑石制备及乙二醇水相重整制氢性能

    潘国祥; 曹枫; 倪哲明; 李小年; 陈海锋; 唐培松; 徐敏虹

    2011-01-01

    The NiMgAI layered double hydroxides (LDHs) with different n(Ni2+)/n(Mg2+)/n(Al3+) (mole ratios) were synthesized by a coprecipitatiun method. The phase composition and catalytic performance of Ni-Mg-AI LDHs were characterized by powder X-ray diffraction, H2-TPR (temperature programmed reduction) and probe reaction of aqueous-phase reforming of ethylene glycol. The results show that the synthesized materials with unitary hydrotaicite phase can be obtained when (n(Ni2+)+n(Mg2+))/n(Al3+) is 1.25-6.50. NiMgA1-LDHs derived catalyst (after reaction) was composed of Ni, MgAI-LDHs and AIO(OH) phases. The reduction process for active content Ni of NiMgAI-LDHs involved two stages. The H2 production rate from aqueous-phase reforming of ethylene glycol (EG) increased with increasing in the reaction temperature and the feeding rate of EG, and decreased with increasing in the reaction pressure. The selectivity of H2 production could be improved when Mg modified to Ni/A1 hydrotalcite, which was related to the basic of supporters. The H2 selectivity decreased and the alkanes selectivity increased with increasing the Ni contents. Considering the selectivity and the activity of Ni based catalysts, we found that the catalytic performance of NiMgAI-LDHs derived catalyst could be superior.%采用共沉淀法成功合成了不同n(Ni2+)/n(Mg2+)/n(Al3+)(摩尔比)的镍镁铝水滑石,用粉末X射线衍射和氢气程序升温还原、乙二醇水相重整制氢探针反应对镍镁铝水滑石的物相、组成、还原过程和催化性能进行表征.结果表明:所形成的纯相水滑石的[n(Ni2+)n(Mg2+)]/n(Al3+)为1.25~6.50.NiMgAl水滑石衍生催化剂(反应后)的物相由Ni、MgAl水滑石和AlO(OH)相组成.催化剂前躯体还原过程包括层板镍还原和复合氧化物中镍还原两步.随着反应温度和给料速率增加、反应压力降低,乙二醇水相重整制氢产率依次增加.随着Mg含量增加,其氢气选择性呈增加趋势;增加Ni含量,

  11. Kinetics and Mechanism of Oxidation of Triethylene Glycol and Tetraethylene Glycol by Ditelluratoargentate (III in Alkaline Medium

    Jinhuan Shan

    2013-01-01

    Full Text Available The kinetics of oxidation of triethylene glycol and tetraethylene glycol by ditelluratoargentate (III (DTA in alkaline liquids has been studied spectrophotometrically in the temperature range of 293.2 K–313.2 K. The reaction rate showed first-order dependence in DTA and fractional order with respect to triethylene glycol or tetraethylene glycol. It was found that the pseudo-first-order rate constant (kobs increased with an increase in concentration of OH− and a decrease in concentration of H4TeO6 2−. There was a negative salt effect and no free radicals were detected. A plausible mechanism involving a two-electron transfer was proposed, and the rate equations derived from the mechanism explained all the experimental results and observations. The activation parameters along with the rate constants of the rate-determining step were calculated.

  12. [Determination of ethylene glycol in biological fluids--propylene glycol interferences].

    Gomółka, Ewa; Cudzich-Czop, Sylwia; Sulka, Adrianna

    2013-01-01

    Many laboratories in Poland do not use gas chromatography (GC) method for determination of ethylene glycol (EG) and methanol in blood of poisoned patients, they use non specific spectrophotometry methods. One of the interfering substances is propylene glycol (PG)--compound present in many medical and cosmetic products: drops, air freshens, disinfectants, electronic cigarettes and others. In Laboratory of Analytical Toxicology and Drug Monitoring in Krakow determination of EG is made by GC method. The method enables to distinguish and make resolution of (EG) and (PG) in biological samples. In the years 2011-2012 in several serum samples from diagnosed patients PG was present in concentration from several to higher than 100 mg/dL. The aim of the study was to estimate PG interferences of serum EG determination by spectrophotometry method. Serum samples containing PG and EG were used in the study. The samples were analyzed by two methods: GC and spectrophotometry. Results of serum samples spiked with PG with no EG analysed by spectrophotometry method were improper ("false positive"). The results were correlated to PG concentration in samples. Calculated cross-reactivity of PG in the method was 42%. Positive results of EG measured by spectrophotometry method must be confirmed by reference GC method. Spectrophotometry method shouldn't be used for diagnostics and monitoring of patients poisoned by EG. PMID:24466683

  13. Sources of propylene glycol and glycol ethers in air at home.

    Choi, Hyunok; Schmidbauer, Norbert; Spengler, John; Bornehag, Carl-Gustaf

    2010-12-01

    Propylene glycol and glycol ether (PGE) in indoor air have recently been associated with asthma and allergies as well as sensitization in children. In this follow-up report, sources of the PGEs in indoor air were investigated in 390 homes of pre-school age children in Sweden. Professional building inspectors examined each home for water damages, mold odour, building's structural characteristics, indoor temperature, absolute humidity and air exchange rate. They also collected air and dust samples. The samples were analyzed for four groups of volatile organic compounds (VOCs) and semi-VOCs (SVOCs), including summed concentrations of 16 PGEs, 8 terpene hydrocarbons, 2 Texanols, and the phthalates n-butyl benzyl phthalate (BBzP), and di(2-ethylhexyl)phthalate (DEHP). Home cleaning with water and mop ≥ once/month, repainting ≥ one room prior to or following the child's birth, and "newest" surface material in the child's bedroom explained largest portion of total variability in PGE concentrations. High excess indoor humidity (g/m³) additionally contributed to a sustained PGE levels in indoor air far beyond several months following the paint application. No behavioral or building structural factors, except for water-based cleaning, predicted an elevated terpene level in air. No significant predictor of Texanols emerged from our analysis. Overall disparate sources and low correlations among the PGEs, terpenes, Texanols, and the phthalates further confirm the lack of confounding in the analysis reporting the associations of the PGE and the diagnoses of asthma, rhinitis, and eczema, respectively. PMID:21318004

  14. Hydroxynortriptyline of Empty Fruit Bunches Fibre using Polyethylene glycol (PEG)

    The aim of this study was to investigate the reaction of oil palm empty fruit bunches fibre (EFBF) via chemical modification and hydroxynortriptyline method using polyethylene glycol (PEG). The first stage was the modification of EFB fibre using NaOH and isopropanol. The next stage was the preparation of hydroxypropylated-empty fruit bunches fibre (HP-EFBF), using different molecular weight of PEG (6,000, 8,000 and 10,000). The characterisation involved in this study were conducted by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), determination of kinetic activation energy (Ea), X-ray diffraction (XRD), cellulose crystallinity index (CrI) and weight increment of the HP-EFB fibre. SEM results showed the surface of HP-EFBF swelled and craters formed along the surface of the fibre. IR spectrum also showed OH stretching band in EFB without treatment is 3402 cm-1, but after hydroxynortriptyline process, the OH stretching band in HP-EFBF (10000, 8000 and 6000) slightly shifted to 3392, 3384 and 3370 cm-1, respectively. TGA showed the thermal stability of HP-EFBF 6,000 was lower than HP-EFBF 8,000 and 10,000. After chemical modification, the activation energy, Ea increased from 32.4 to 51.9 kJ/ mol more than EFB without treatment, 12.5 kJ/ mol. XRD showed that diffraction peak (002) shifted to the smaller 2θ angle and the peaks (101, 10I) disappeared after hydroxynortriptyline process. Crystallinity index, of EFB without treatment decreased from 27 % to 25 % after chemical modification. The higher the molecular weight of the PEG, the greater the weight increment of the HP-EFBF. (author)

  15. Polypropylene Glycol-Silver Nanoparticle Composites: A Novel Anticorrosion Material for Aluminum in Acid Medium

    Solomon, Moses M.; Umoren, Saviour A.; Israel, Aniekemeabasi U.; Ebenso, Eno E.

    2015-11-01

    Admixture of polypropylene glycol and 1 mM AgNO3 together with natural honey as reducing and stabilizing agent was employed to prepare in situ polypropylene glycol/silver nanoparticle (PPG/AgNPs) composite. The prepared PPG/AgNPs composite was characterized by UV-Vis spectroscopy, FTIR, XRD, and EDS, while the morphology of the Ag nanoparticles in the composite was obtained by TEM. TEM results revealed that the Ag nanoparticles were spherical in shape. The anticorrosion property of PPG/AgNPs composite was examined by electrochemical, weight loss, SEM, EDS, and water contact angle measurements. Results obtained show that PPG/AgNPs are effective in retarding the dissolution of Al in an acid-induced corrosive environment. Inhibition efficiency increased with the increasing composite concentration but decreased with the increasing temperature. Potentiodynamic polarization results revealed that PPG/AgNPs functions as a mixed-type corrosion inhibitor. The adsorption of the composite onto Al surface was found to follow El-Awady et al. adsorption isotherm model. SEM, EDS, and water contact angle results confirmed the adsorption of PPG/AgNPs films onto Al surface.

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

    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.

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

    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

  18. Determination of glycols in air: development of sampling and analytical methodology and application to theatrical smokes.

    Pendergrass, S M

    1999-01-01

    Glycol-based fluids are used in the production of theatrical smokes in theaters, concerts, and other stage productions. The fluids are heated and dispersed in aerosol form to create the effect of a smoke, mist, or fog. There have been reports of adverse health effects such as respiratory irritation, chest tightness, shortness of breath, asthma, and skin rashes. Previous attempts to collect and quantify the aerosolized glycols used in fogging agents have been plagued by inconsistent results, both in the efficiency of collection and in the chromatographic analysis of the glycol components. The development of improved sampling and analytical methodology for aerosolized glycols was required to assess workplace exposures more effectively. An Occupational Safety and Health Administration versatile sampler tube was selected for the collection of ethylene glycol, propylene glycol, 1,3-butylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol aerosols. Analytical methodology for the separation, identification, and quantitation of the six glycols using gas chromatography/flame ionization detection is described. Limits of detection of the glycol analytes ranged from 7 to 16 micrograms/sample. Desorption efficiencies for all glycol compounds were determined over the range of study and averaged greater than 90%. Storage stability results were acceptable after 28 days for all analytes except ethylene glycol, which was stable at ambient temperature for 14 days. Based on the results of this study, the new glycol method was published in the NIOSH Manual of Analytical Methods. PMID:10462779

  19. Effect of ethylene glycol dimethacrylate on swelling and on metformin hydrochloride release behavior of chemically crosslinked pH–sensitive acrylic acid–polyvinyl alcohol hydrogel

    Akhtar, Muhammad Faheem; Ranjha, Nazar Muhammad; Hanif, Muhammad

    2015-01-01

    Background The present work objective was to prepare and to observe the effect of ethylene glycol dimethacrylate on swelling and on drug release behavior of pH-sensitive acrylic acid–polyvinyl alcohol hydrogel. Methods In the present work, pH sensitive acrylic acid–polyvinyl alcohol hydrogels have been prepared by free radical polymerization technique in the presence of benzoyl peroxide as an initiator. Different crosslinker contents were used to observe its effect on swelling and on drug rel...

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

    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

  1. GLYCOLIC-NITRIC ACID FLOWSHEET DEMONSTRATION OF THE DWPF CHEMICAL PROCESS CELL WITH SLUDGE AND SUPERNATE SIMULANTS

    Lambert, D.; Stone, M.; Newell, J.; Best, D.; Zamecnik, J.

    2012-08-28

    Savannah River Remediation (SRR) is evaluating changes to its current Defense Waste Processing Facility (DWPF) flowsheet to improve processing cycle times. This will enable the facility to support higher canister production while maximizing waste loading. Higher throughput is needed in the Chemical Process Cell (CPC) since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the DWPF gas chromatographs (GC) and the potential for production of flammable quantities of hydrogen, reducing or eliminating the amount of formic acid used in the CPC is being developed. Earlier work at Savannah River National Laboratory has shown that replacing formic acid with an 80:20 molar blend of glycolic and formic acids has the potential to remove mercury in the SRAT without any significant catalytic hydrogen generation. This report summarizes the research completed to determine the feasibility of processing without formic acid. In earlier development of the glycolic-formic acid flowsheet, one run (GF8) was completed without formic acid. It is of particular interest that mercury was successfully removed in GF8, no formic acid at 125% stoichiometry. Glycolic acid did not show the ability to reduce mercury to elemental mercury in initial screening studies, which is why previous testing focused on using the formic/glycolic blend. The objective of the testing detailed in this document is to determine the viability of the nitric-glycolic acid flowsheet in processing sludge over a wide compositional range as requested by DWPF. This work was performed under the guidance of Task Technical and Quality Assurance Plan (TT&QAP). The details regarding the simulant preparation and analysis have been documented previously.

  2. GLYCOLIC-NITRIC ACID FLOWSHEET DEMONSTRATION OF THE DWPF CHEMICAL PROCESSING CELL WITH MATRIX SIMULANTS AND SUPERNATE

    Lambert, D.; Stone, M.; Newell, J.; Best, D.

    2012-05-07

    Savannah River Remediation (SRR) is evaluating changes to its current DWPF flowsheet to improve processing cycle times. This will enable the facility to support higher canister production while maximizing waste loading. Higher throughput is needed in the CPC since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the DWPF gas chromatographs (GC) and the potential for production of flammable quantities of hydrogen, reducing or eliminating the amount of formic acid used in the CPC is being developed. Earlier work at Savannah River National Laboratory has shown that replacing formic acid with an 80:20 molar blend of glycolic and formic acids has the potential to remove mercury in the SRAT without any significant catalytic hydrogen generation. This report summarizes the research completed to determine the feasibility of processing without formic acid. In earlier development of the glycolic-formic acid flowsheet, one run (GF8) was completed without formic acid. It is of particular interest that mercury was successfully removed in GF8, no formic acid at 125% stoichiometry. Glycolic acid did not show the ability to reduce mercury to elemental mercury in initial screening studies, which is why previous testing focused on using the formic/glycolic blend. The objective of the testing detailed in this document is to determine the viability of the nitric-glycolic acid flowsheet in processing sludge over a wide compositional range as requested by DWPF. This work was performed under the guidance of Task Technical and Quality Assurance Plan (TT and QAP). The details regarding the simulant preparation and analysis have been documented previously.

  3. A new formulation of curcumin using poly (lactic-co-glycolic acid)—polyethylene glycol diblock copolymer as carrier material

    Phuong Tuyen Dao, Thi; Hoai Nguyen, To; To, Van Vinh; Ho, Thanh Ha; Nguyen, Tuan Anh; Chien Dang, Mau

    2014-09-01

    The aim of this study is to fabricate a nanoparticle formulation of curcumin using a relatively new vehicle as the matrix polymer: poly(lactic-co-glycolic acid) (PLGA)- polyethylene glycol (PEG) diblock copolymer, and to investigate the effects of the various processing parameters on the characteristics of nanoparticles (NPs). We successfully synthesized the matrix polymer of PLGA-PEG by conjugation of PLGA copolymer with a carboxylate end group to a heterobifunctional amine-PEG-methoxy using N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide as conjugation crosslinkers. The composition of the formed product (PLGA-PEG) was characterized with 500 MHz 1H nuclear magnetic resonance (NMR). The conjugation of PLGA-PEG was confirmed using Fourier transform infrared (FTIR) spectrum study. This diblock copolymer was then used to prepare the curcumin-loaded NPs through nanoprecipitation technique. With this method, we found that the size distribution depends on the type of solvent, the concentration of polymer and the concentration of surfactant. The particle size and size distribution were measured by dynamic light scattering (DLS). Transmission electron microscope (TEM) and scanning electron microscope (SEM) were used to confirm the size, structure and morphology of the successfully prepared NPs. All of our results showed that they are spherical and quite homologous with mean diameter around of 100-300 nm. Further, we evaluated encapsulation efficiency and some characteristics of NPs through high performance liquid chromatography (HPLC) analyses, zeta-potential measurements and x-ray diffraction studies. The HPLC analyses were performed to determine the amount of curcumin entrapped in NPs. The zeta-potential measurements confirmed the stability of NPs and the successful encapsulation of curcumin within NPs and the x-ray diffraction patterns showed the disordered-crystalline phase of curcumin inside the polymeric matrix.

  4. A new formulation of curcumin using poly (lactic-co-glycolic acid)—polyethylene glycol diblock copolymer as carrier material

    The aim of this study is to fabricate a nanoparticle formulation of curcumin using a relatively new vehicle as the matrix polymer: poly(lactic-co-glycolic acid) (PLGA)- polyethylene glycol (PEG) diblock copolymer, and to investigate the effects of the various processing parameters on the characteristics of nanoparticles (NPs). We successfully synthesized the matrix polymer of PLGA-PEG by conjugation of PLGA copolymer with a carboxylate end group to a heterobifunctional amine-PEG-methoxy using N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide as conjugation crosslinkers. The composition of the formed product (PLGA-PEG) was characterized with 500 MHz 1H nuclear magnetic resonance (NMR). The conjugation of PLGA-PEG was confirmed using Fourier transform infrared (FTIR) spectrum study. This diblock copolymer was then used to prepare the curcumin-loaded NPs through nanoprecipitation technique. With this method, we found that the size distribution depends on the type of solvent, the concentration of polymer and the concentration of surfactant. The particle size and size distribution were measured by dynamic light scattering (DLS). Transmission electron microscope (TEM) and scanning electron microscope (SEM) were used to confirm the size, structure and morphology of the successfully prepared NPs. All of our results showed that they are spherical and quite homologous with mean diameter around of 100–300 nm. Further, we evaluated encapsulation efficiency and some characteristics of NPs through high performance liquid chromatography (HPLC) analyses, zeta-potential measurements and x-ray diffraction studies. The HPLC analyses were performed to determine the amount of curcumin entrapped in NPs. The zeta-potential measurements confirmed the stability of NPs and the successful encapsulation of curcumin within NPs and the x-ray diffraction patterns showed the disordered-crystalline phase of curcumin inside the polymeric matrix. (paper)

  5. Ethylene glycol and propylene glycol ethers – Reproductive and developmental toxicity

    Beata Starek-Świechowicz

    2015-10-01

    Full Text Available Both ethylene and propylene glycol alkyl ethers (EGAEs and PGAEs, respectively are widely used, mainly as solvents, in industrial and household products. Some EGAEs demonstrate gonadotoxic, embriotoxic, fetotoxic and teratogenic effects in both humans and experimental animals. Due to the noxious impact of these ethers on reproduction and development of organisms EGAEs are replaced for considerably less toxic PGAEs. The data on the mechanisms of testicular, embriotoxic, fetotoxic and teratogenic effects of EGAEs are presented in this paper. Our particular attention was focused on the metabolism of some EGAEs and their organ-specific toxicities, apoptosis of spermatocytes associated with changes in the expression of various genes that code for oxidative stress factors, protein kinases and nuclear hormone receptors. Med Pr 2015;66(5:725–737

  6. [Secondary hyperoxaluria and nephrocalcinosis due to ethylene glycol poisoning].

    Monet, C; Richard, E; Missonnier, S; Rebouissoux, L; Llanas, B; Harambat, J

    2013-08-01

    We report the case of a 3-year-old boy admitted to the pediatric emergency department for ethylene glycol poisoning. During hospitalization, he presented dysuria associated with crystalluria. Blood tests showed metabolic acidosis with an elevated anion gap. A renal ultrasound performed a few weeks later revealed bilateral medullary hyperechogenicity. Urine microscopic analysis showed the presence of weddellite crystals. Secondary nephrocalcinosis due to ethylene glycol intoxication was diagnosed. Hyperhydration and crystallization inhibition by magnesium citrate were initiated. Despite this treatment, persistent weddellite crystals and nephrocalcinosis were seen more than 2years after the intoxication. Ethylene glycol is metabolized in the liver by successive oxidations leading to its final metabolite, oxalic acid. Therefore, metabolic acidosis with an elevated anion gap is usually found following ethylene glycol intoxication. Calcium oxalate crystal deposition may occur in several organs, including the kidneys. The precipitation of calcium oxalate in renal tubules can lead to nephrocalcinosis and acute kidney injury. The long-term renal prognosis is related to chronic tubulointerstitial injury caused by nephrocalcinosis. Treatment of ethylene glycol intoxication is based on specific inhibitors of alcohol dehydrogenase and hemodialysis in the most severe forms, and should be started promptly. PMID:23827374

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

    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.

  8. Sources of Propylene Glycol and Glycol Ethers in Air at Home

    Hyunok Choi

    2010-12-01

    Full Text Available Propylene glycol and glycol ether (PGE in indoor air have recently been associated with asthma and allergies as well as sensitization in children. In this follow-up report, sources of the PGEs in indoor air were investigated in 390 homes of pre-school age children in Sweden. Professional building inspectors examined each home for water damages, mold odour, building’s structural characteristics, indoor temperature, absolute humidity and air exchange rate. They also collected air and dust samples. The samples were analyzed for four groups of volatile organic compounds (VOCs and semi-VOCs (SVOCs, including summed concentrations of 16 PGEs, 8 terpene hydrocarbons, 2 Texanols, and the phthalates n-butyl benzyl phthalate (BBzP, and di(2-ethylhexylphthalate (DEHP. Home cleaning with water and mop ≥ once/month, repainting ≥ one room prior to or following the child’s birth, and “newest” surface material in the child’s bedroom explained largest portion of total variability in PGE concentrations. High excess indoor humidity (g/m3 additionally contributed to a sustained PGE levels in indoor air far beyond several months following the paint application. No behavioral or building structural factors, except for water-based cleaning, predicted an elevated terpene level in air. No significant predictor of Texanols emerged from our analysis. Overall disparate sources and low correlations among the PGEs, terpenes, Texanols, and the phthalates further confirm the lack of confounding in the analysis reporting the associations of the PGE and the diagnoses of asthma, rhinitis, and eczema, respectively.

  9. Pt Ru/C electrocatalysts prepared using electron beam irradiation

    Pt Ru/C electrocatalysts (carbon-supported Pt Ru nanoparticles) were prepared submitting water/ethylene glycol solutions containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The water/ethylene glycol ratio (v/v) was evaluated as synthesis parameters. The Pt Ru/C electrocatalysts were prepared with a nominal Pt:Ru atomic ratio of 50:50 and were characterized by energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) and tested for methanol electro-oxidation using cyclic voltammetry and chronoamperometry. The obtained Pt Ru/C electrocatalysts showed the typical fcc structure of platinum-ruthenium alloys and the electrocatalytic activity depends on the water/ethylene glycol ratio used in the preparation

  10. Nitric-glycolic flowsheet testing for maximum hydrogen generation rate

    Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site is developing for implementation a flowsheet with a new reductant to replace formic acid. Glycolic acid has been tested over the past several years and found to effectively replace the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the chemical generation of hydrogen and ammonia, allows purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective adjustment of the SRAT/SME rheology, and is favorable with respect to melter flammability. The objective of this work was to perform DWPF Chemical Process Cell (CPC) testing at conditions that would bound the catalytic hydrogen production for the nitric-glycolic flowsheet.

  11. Preparation and characterization of ethosomes for topical delivery of aceclofenac

    Barupal A; Gupta Vandana; Ramteke Suman

    2010-01-01

    The aim of present study was to prepare and characterized ethosomes of aceclofenac which may deliver the drug to targeted site more efficiently than marketed gel preparation and also overcome the problems related with oral administration of drug. The formulations were prepared with varying the quantity of ethanol 10-50% (v/v), lecithin 1-4% (w/v), propylene glycol 5-20% (v/v) and evaluated for their vesicle size, shape and surface morphology, entrapment efficiency and in ...

  12. Liver-targeting Resibufogenin-loaded poly(lactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles for liver cancer therapy

    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

  13. Enzymatic remediated biodegradation of propylene glycol 1,2-dinitrate

    Meng, M.; Geelhaar, L.; Speedie, M.K. [Univ. of Maryland, Baltimore, MD (United States)

    1995-12-31

    Two bacterial species, Enterobacter agglomerans and Bacillus thuringiensis/cereus, which were selected from nitroglycerin (GTN) contaminated soil, have previously been shown to have denitrating ability on nitroglycerin. This abstract presents the investigation of the cell free extracts from both microorganisms for the degradation of another nitrate ester contaminant; propylene glycol 1,2-dinitrate (PGDN). This compound has been previously considered resistant to the biodegradation. In order to probe the pathway, the whole process was monitored by using [1-{sup 14}C]-PGDN as substrate and the intermediates were identified by HPLC and TLC chromatography. Long term biodegradation experiments have shown that the enzymes in the cytoplasm fraction of Bacillus thuringiensis/cereus and the membrane fraction of Enterobacter agglomerans convert PGDN successively into propylene glycol 1-mononitrate (1-PGMN) and propylene glycol 2-mononitrate (2-PGMN), and finally, propylene glycol. The capacity to achieve sequential and complete degradation of PGDN implies that it follows a similar mechanism to that observed in the GTN degradation. Cofactor requirements for PGDN breakdown have been studied, it was found that no dissociable, dialyzable cofactors are required.

  14. A radioimmunoprecipitation polyethylene glycol assay for circulating Entamoeba histolytica antigens

    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. (Auth.)

  15. Radioimmunoprecipitation polyethylene glycol assay for circulating Entamoeba histolytica antigens

    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.

  16. A rapid analysis of plasma/serum ethylene and propylene glycol by headspace gas chromatography.

    Ehlers, Alexandra; Morris, Cory; Krasowski, Matthew D

    2013-12-01

    A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using 1,3-propanediol as the internal standard. The method employed a single-step derivitization using phenylboronic acid, was linear to 200 mg/dL and had a lower limit of quantitation of 1 mg/dL suitable for clinical analyses. The analytical method described allows for laboratories with HS-GC instrumentation to analyze ethanol, methanol, isopropanol, ethylene glycol, and propylene glycol on a single instrument with rapid switch-over from alcohols to glycols analysis. In addition to the novel HS-GC method, a retrospective analysis of patient specimens containing ethylene glycol and propylene glycol was also described. A total of 36 patients ingested ethylene glycol, including 3 patients who presented with two separate admissions for ethylene glycol toxicity. Laboratory studies on presentation to hospital for these patients showed both osmolal and anion gap in 13 patients, osmolal but not anion gap in 13 patients, anion but not osmolal gap in 8 patients, and 1 patient with neither an osmolal nor anion gap. Acidosis on arterial blood gas was present in 13 cases. Only one fatality was seen; this was a patient with initial serum ethylene glycol concentration of 1282 mg/dL who died on third day of hospitalization. Propylene glycol was common in patients being managed for toxic ingestions, and was often attributed to iatrogenic administration of propylene glycol-containing medications such as activated charcoal and intravenous lorazepam. In six patients, propylene glycol contributed to an abnormally high osmolal gap. The common presence of propylene glycol in hospitalized patients emphasizes the importance of being able to identify both ethylene glycol and propylene glycol by chromatographic methods. PMID:23741644

  17. Processes and systems for the production of propylene glycol from glycerol

    Frye, John G; Oberg, Aaron A; Zacher, Alan H

    2015-01-20

    Processes and systems for converting glycerol to propylene glycol are disclosed. The glycerol feed is diluted with propylene glycol as the primary solvent, rather than water which is typically used. The diluted glycerol feed is sent to a reactor where the glycerol is converted to propylene glycol (as well as other byproducts) in the presence of a catalyst. The propylene glycol-containing product from the reactor is recycled as a solvent for the glycerol feed.

  18. Impact of scaling on the nitric-glycolic acid flowsheet

    Lambert, D. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-02-01

    Savannah River Remediation (SRR) is considering using glycolic acid as a replacement for formic acid in Sludge Receipt and Adjustment Tank (SRAT) processing in the Defense Waste Processing Facility (DWPF). Catalytic decomposition of formic acid is responsible for the generation of hydrogen, a potentially flammable gas, during processing. To prevent the formation of a flammable mixture in the offgas, an air purge is used to dilute the hydrogen concentration below the 60% of the Composite Lower Flammability Limit (CLFL). The offgas is continuously monitored for hydrogen using Gas Chromatographs (GCs). Since formic acid is much more volatile and toxic than glycolic acid, a formic acid spill would lead to the release of much larger quantities to the environment. Switching from formic acid to glycolic acid is expected to eliminate the hydrogen flammability hazard leading to lower air purges, thus downgrading of Safety Significant GCs to Process Support GCs, and minimizing the consequence of a glycolic acid tank leak in DWPF. Overall this leads to a reduction in process operation costs and an increase in safety margin. Experiments were completed at three different scales to demonstrate that the nitric-glycolic acid flowsheet scales from the 4-L lab scale to the 22-L bench scale and 220-L engineering scale. Ten process demonstrations of the sludge-only flowsheet for SRAT and Slurry Mix Evaporator (SME) cycles were performed using Sludge Batch 8 (SB8)-Tank 40 simulant. No Actinide Removal Process (ARP) product or strip effluent was added during the runs. Six experiments were completed at the 4-L scale, two experiments were completed at the 22-L scale, and two experiments were completed at the 220-L scale. Experiments completed at the 4-L scale (100 and 110% acid stoichiometry) were repeated at the 22-L and 220-L scale for scale comparisons.

  19. Impact of scaling on the nitric-glycolic acid flowsheet

    Savannah River Remediation (SRR) is considering using glycolic acid as a replacement for formic acid in Sludge Receipt and Adjustment Tank (SRAT) processing in the Defense Waste Processing Facility (DWPF). Catalytic decomposition of formic acid is responsible for the generation of hydrogen, a potentially flammable gas, during processing. To prevent the formation of a flammable mixture in the offgas, an air purge is used to dilute the hydrogen concentration below the 60% of the Composite Lower Flammability Limit (CLFL). The offgas is continuously monitored for hydrogen using Gas Chromatographs (GCs). Since formic acid is much more volatile and toxic than glycolic acid, a formic acid spill would lead to the release of much larger quantities to the environment. Switching from formic acid to glycolic acid is expected to eliminate the hydrogen flammability hazard leading to lower air purges, thus downgrading of Safety Significant GCs to Process Support GCs, and minimizing the consequence of a glycolic acid tank leak in DWPF. Overall this leads to a reduction in process operation costs and an increase in safety margin. Experiments were completed at three different scales to demonstrate that the nitric-glycolic acid flowsheet scales from the 4-L lab scale to the 22-L bench scale and 220-L engineering scale. Ten process demonstrations of the sludge-only flowsheet for SRAT and Slurry Mix Evaporator (SME) cycles were performed using Sludge Batch 8 (SB8)-Tank 40 simulant. No Actinide Removal Process (ARP) product or strip effluent was added during the runs. Six experiments were completed at the 4-L scale, two experiments were completed at the 22-L scale, and two experiments were completed at the 220-L scale. Experiments completed at the 4-L scale (100 and 110% acid stoichiometry) were repeated at the 22-L and 220-L scale for scale comparisons.

  20. Tetraethylene glycol thermooxidation and the influence of certain compounds relevant to conserved archaeological wood

    Mortensen, Martin Nordvig; Egsgaard, Helge; Hvilsted, Søren; Shashoua, Yvonne; Glastrup, Jens

    2012-01-01

    The degradation of tetraethylene glycol (TEG) was studied at 70 °C under dry air and nitrogen. Degradation products were detected using gas chromatography-mass spectrometry (GC–MS). They were mono-, di- and tri-ethylene glycol, mono- and di-formates of mono-, di-, tri- and tetra-ethylene glycol and...

  1. 21 CFR 500.50 - Propylene glycol in or on cat food.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol in or on cat food. 500.50 Section... Propylene glycol in or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat food is not generally recognized as safe and is a food additive subject to section 409...

  2. Thermo-Responsive Hydrogels Based on Branched Poly(L-lactide)-poly(ethylene glycol) Copolymers

    Velthoen, Ingrid W.; Tijsma, Edze J.; Dijkstra, Pieter J.; Feijen, Jan

    2008-01-01

    Branched poly(L-lactide)-poly(ethylene glycol) (PLLA-PEG) block copolymers were synthesized from trifunctional PLLA and amine functionalized methoxy poly(ethylene glycol)s. The copolymers in water formed hydrogels that showed thermo-responsive behavior. The hydrogels underwent a gel to sol transitio

  3. 21 CFR 172.765 - Succistearin (stearoyl propylene glycol hydrogen succinate).

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Succistearin (stearoyl propylene glycol hydrogen succinate). 172.765 Section 172.765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... propylene glycol hydrogen succinate). The food additive succistearin (stearoyl propylene glycol...

  4. Liquid-liquid equilibria for glycols plus hydrocarbons: Data and correlation

    Derawi, Samer; Kontogeorgis, Georgios; Stenby, Erling Halfdan;

    2002-01-01

    Liquid-liquid equilibrium data for seven binary glycol-hydrocarbon systems have been measured in the temperature range 32 degreesC to 80 degreesC and at the pressure 1 bar. The measured systems are monoethylene glycol (MEG) + heptane, methyleyclohexane (MCH) + hexane, propylene glycol (PG...

  5. Transactivating-transduction protein-polyethylene glycol modified liposomes traverse the blood-spinal cord and blood-brain barriers

    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.

  6. Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds

    Nor Monica Ahmad

    2016-06-01

    Full Text Available 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.

  7. Biocompatible and bioadhesive hydrogels based on 2-hydroxyethyl methacrylate, monofunctional poly(alkylene glycols and itaconic acid

    Mićić Maja M.

    2007-01-01

    Full Text Available New types of hydrogels were prepared by the radical copolymerization of 2-hydroxyethyl methacrylate, itaconic acid and four different poly(alkylene glycol (methacrylate components (Bisomers in a water/ethanol mixture as solvent. The polymers swell in water at 25°C to yield homogeneous transparent hydrogels. All the hydrogels displayed pH sensitive behavior in buffers of the pH range from 2.20 to 7.40, under conditions similar to those of biological fluids. The presence of these two comonomers, which were added to HEMA, increased the swelling degree of the hydrogels and gave gels with better elasticity. The hydrogels were thermally stable in the vicinity of the physiological temperature (37°C. The copolymer containing pure poly(ethylene glycol acrylate units generally had the best properties. The tests performed on the hydrogels confirmed that they were neither hemolytic nor cytotoxic. The copolymer samples showed better cell viability and less hemolytic activity than the PHEMA sample, confirming the assumption that poly(alkylene glycols improve the biocompatibility of hydrogels. Due to their swelling and mechanical characteristics, as well as the very good biocompatibility and bioadhesive properties, poly(Bisomer/HEMA/IA hydrogels are promising for utilization in the field of biomedicals, especially for the controlled release of drugs.

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

    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.

  9. Fabrication of poly hydroxybutyrate-polyethylene glycol-folic acid nanoparticles loaded by paclitaxel.

    Rezaei, Fatemeh; Rafienia, Mohammad; Keshvari, Hamid; Sattary, Mansooreh; Naeimi, Mitra; Keyvani, Hossein

    2016-01-01

    In this study drug (paclitaxel)-loaded nanoparticles of poly hydroxybutyrate-polyethylene glycol-folic acid (PHB-PEG-FOL) were prepared by using an oil-in-water (O/W) emulsion-solvent evaporation method. The functionalization and conjugation steps in the chemical synthesis were confirmed using Fourier transform infrared (FTIR) and nuclear magnetic resonance tests ((1)H NMR). Morphology of nanoparticles was evaluated by scanning electron microscopy (SEM). Nanoparticles were characterized by particle size analyzer. Between two samples containing drug, the lower doses showed more homogeneous distribution, and the lowest aggregation. The drug release profiles showed a two-phase release including initial rapid release and a continuous release. MG63 cells were used to evaluate cytotoxicity. The cytotoxicity of PHB-PEG-FOL nanoparticles with drug against cancer cells was much higher and longer than free drug sample. These nanoparticles were successfully synthesized as a novel system for targeted drug delivery against cancer cells. PMID:26234551

  10. Synthesis of carbon nanofibres from a liquid solution containing both catalyst and polyethylene glycol

    Carbon nanofibres (CNFs) exhibiting bamboo-like, hollow fibril morphology were prepared from a mixture of polyethylene glycol (PEG) and iron-based compounds such as Fe2(SO4)3·nH2O, Fe(NO3)·9H2O or FeO(OH) by a thermal process. These materials were well mixed in distilled water prior to thermal treatment in an air/nitrogen atmosphere. With increasing temperature, the mixture underwent solvent removal, dehydrogenation, thermal decomposition, carbonization and catalytic graphitization to form CNFs. Results show that CNFs can be formed with different PEG/catalyst ratios (100/1-1000/1 by weight) at 750 deg. C. The catalyst effect is discussed for the formation of bamboo-like CNFs. The diameter of the CNFs was about 30-50 nm while the length was a few micrometres

  11. Maltose neopentyl glycol-3 (MNG-3) analogues for membrane protein study

    Cho, Kyung Ho; Husri, Mohd; Amin, Anowarul; Gotfryd, Kamil; Lee, Ho Jin; Go, Juyeon; Kim, Jin Woong; Loland, Claus J; Guan, Lan; Byrne, Bernadette; Chae, Pil Seok

    2015-01-01

    Detergents are typically used to both extract membrane proteins (MPs) from the lipid bilayers and maintain them in solution. However, MPs encapsulated in detergent micelles are often prone to denaturation and aggregation. Thus, the development of novel agents with enhanced stabilization...... characteristics is necessary to advance MP research. Maltose neopentyl glycol-3 (MNG-3) has contributed to >10 crystal structures including G-protein coupled receptors. Here, we prepared MNG-3 analogues and characterised their properties using selected MPs. Most MNGs were superior to a conventional detergent, n......-dodecyl-β-d-maltopyranoside (DDM), in terms of membrane protein stabilization efficacy. Interestingly, optimal stabilization was achieved with different MNG-3 analogues depending on the target MP. The origin for such detergent specificity could be explained by a novel concept: compatibility between detergent hydrophobicity and MP...

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

    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.

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

    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.

  14. Efficient utilization of pentoses for bioproduction of the renewable two-carbon compounds ethylene glycol and glycolate.

    Pereira, Brian; Li, Zheng-Jun; De Mey, Marjan; Lim, Chin Giaw; Zhang, Haoran; Hoeltgen, Claude; Stephanopoulos, Gregory

    2016-03-01

    The development of lignocellulose as a sustainable resource for the production of fuels and chemicals will rely on technology capable of converting the raw materials into useful compounds; some such transformations can be achieved by biological processes employing engineered microorganisms. Towards the goal of valorizing the hemicellulose fraction of lignocellulose, we designed and validated a set of pathways that enable efficient utilization of pentoses for the biosynthesis of notable two-carbon products. These pathways were incorporated into Escherichia coli, and engineered strains produced ethylene glycol from various pentoses, including simultaneously from D-xylose and L-arabinose; one strain achieved the greatest reported titer of ethylene glycol, 40g/L, from D-xylose at a yield of 0.35g/g. The strategy was then extended to another compound, glycolate. Using D-xylose as the substrate, an engineered strain produced 40g/L glycolate at a yield of 0.63g/g, which is the greatest reported yield to date. PMID:26711083

  15. Preparation of mesoporous silica films SBA-15 over different substrates

    Mesoporous materials have been target of frequent interest due to its wide application possibilities, for example development of gas sensors, catalysis, molecules transportation, pharmaceuticals release, synthesis of auto-organized nanostructures, among others. The possibilities of application are enhanced when such materials are disposed in the form of thin and ultrathin films. In this work the preparation of mesoporous SBA-15 silica films is explored by means of the dipcoating technique of a sol-gel on different substrates (glass slides, stainless steel, copper), using the surfactant poly(ethylene glycol)-block-poly(propylene glycol)- block-poly(ethylene glycol), known as P123, a block copolymer. Synthesis parameters surfactant concentration, aging time and temperature were investigated. In this work we present the morphological and structural characterization of the prepared films, which were obtained using atomic force microscopy and x-ray fluorescence and diffraction. (author)

  16. Complexation hydrogels for intestinal delivery of interferon β and calcitonin

    Kamei, Noriyasu; Morishita, Mariko; Chiba, Hitomi; Kavimandan, Nikhil J.; Peppas, NicholasA.; Takayama, Kozo

    2008-01-01

    Recent studies have suggested that complexation hydrogels poly(methacrylic acid-g-ethylene glycol) (henceforth designated as P(MAA-g-EG)) exhibit high insulin incorporation efficiency, rapid insulin release in the intestine based on their pH-dependent complexation properties, enzyme-inhibiting effects and mucoadhesive characteristics. Therefore, they are promising carriers for insulin delivery via an oral route. As we designed these hydrogels as carriers suitable for oral administration of va...

  17. Heteromerous interactions among glycolytic enzymes and of glycolytic enzymes with F-actin: effects of poly(ethylene glycol).

    Walsh, J L; Knull, H R

    1988-01-01

    Interactions of glucose-6-phosphate isomerase (D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9), aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate lyase, EC 4.1.2.13), glyceraldehyde-3-phosphate dehydrogenase (D-glyceraldehyde-3-phosphate:NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12), triose-phosphate isomerase (D-glyceraldehyde-3-phosphate ketol-isomerase, EC 5.3.1.1), phosphoglycerate mutase (D-phosphoglycerate 2,3-phosphomutase, EC 5.4.2.1), phosphoglycerate kinase (ATP:3-phospho-D-glycerate 1-phosphotransferase, EC 2.7.3), enolase (2-phospho-D-glycerate hydro-lyase, EC 4.2.1.11), pyruvate kinase (ATP:Pyruvate O2-phosphotransferase, EC 2.7.1.40) and lactate dehydrogenase [S)-lactate:NAD+ oxidoreductase, EC 1.1.1.27) with F-actin, among the glycolytic enzymes listed above, and with phosphofructokinase (ATP:D-fructose-6-phosphate 1-phosphotransferase, EC 2.7.1.11) were studied in the presence of poly(ethylene glycol). Both purified rabbit muscle enzymes and rabbit muscle myogen, a high-speed supernatant fraction containing the glycolytic enzymes, were used to study enzyme-F-actin interactions. Following ultracentrifugation, F-actin and poly(ethylene glycol) tended to increase and KCl to decrease the pelleting of enzymes. In general, the greater part of the pelleting occurred in the presence of both F-actin and poly(ethylene glycol) and the absence of KCl. Enzymes that pelleted more in myogen preparations than as individual purified enzymes in the presence of poly(ethylene glycol) and the absence of F-actin were tested for specific enzyme-enzyme associations, several of which were observed. Such interactions support the view that the internal cell structure is composed of proteins that interact with one another to form the microtrabecular lattice. PMID:3334856

  18. Modification of dense TiO2 particles using polyethylene glycol template: Synthesis, characterization, and photocatalytic activity

    Dostanić, J.; Lončarević, D.; Radosavljević-Mihajlović, A.; Jovanović, D. M.

    2015-12-01

    In this study, an effort has been made to prepare TiO2 materials by sol-gel technique using polyethylene glycol (PEG) as pore directing agent. Different PEG amounts were used during samples preparation in order to investigate the change in intrinsic material properties. The photocatalytic activity of prepared catalysts was estimated by measuring the decomposition of arylazo pyridone dye. The optimum template amount was determined, resulting in catalyst with enhanced textural properties, optimal anatase/rutile ratio and hence improved photocatalytic properties. Specific surface area and anatase/rutile ratio were found to be the main contributing factors to the catalyst activity. A synergistic effect between anatase and rutile TiO2 has been observed, since the presence of relatively inactive rutile phase enhanced the photoactivity of mixed TiO2.

  19. Recyclable nickel catalysed Suzuki-Miyaura reaction in the presence of polyethyleneimine under phosphine-free conditions in ethylene glycol

    Nooredin Goudarzian; Mohammad Gholinejad; Parisa Ghahramani

    2011-07-01

    In this report, Suzuki-Miyaura coupling reaction was performed in the presence of polyethyleneimine (PEI) as ligand, NiCl2·6H2O and K2CO3 in ethylene glycol at 80-100°C under phosphinefree conditions. By this method, structurally different aryl bromides and iodides were reacted with phenylboronic acid and potassium phenyltrifluoroborate. Under these simple reaction conditions a different biaryl derivatives have been prepared in high to excellent yields. Recycling experiments showed that catalyst can be used as recyclable catalyst in the Suzuki-Miyaura cross-coupling reactions.

  20. Synthesis of polyacrylate/polyethylene glycol interpenetrating network hydrogel and its sorption of heavy-metal ions

    Qunwei Tang, Xiaoming Sun, Qinghua Li, Jihuai Wu and Jianming Lin

    2009-01-01

    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 Ni2 +, Cr3 + and Cd2 +, the preparation conditions were optimized. In our system, the greatest amount of Ni2 +, Cr3 + and Cd2 + adsorbed were 102.34, ...

  1. Novel thermogelling poly(ε-caprolactone-co-lactide)-poly(ethylene glycol)-poly(ε-caprolactone-co-lactide) aqueous solutions

    Zhi Qiang Jiang; Xian Mo Deng; Jian Yuan Hao

    2007-01-01

    The aqueous solutions of poly(ε-caprolactone-co-lactide)-poly(ethylene glycol)poly(ε-caprolactone-co-lactide) undergoing sol-gel transition as the temperature increases from 20 to 50℃ were successfully prepared.The thermogelling triblock copolymers were synthesized by subtle tuning of the chemical composition and the hydrophilicity/hydrophobicity balance.The sol-gel transition was studied focusing on structure-property relationship.The amphiphilic copolymer formed micelles in aqueous solutions.It is believed to have potential applications in drug delivery and tissue engineering.

  2. A Novel Synthesis Method of Porous Calcium Silicate Hydrate Based on the Calcium Oxide/Polyethylene Glycol Composites

    Wei Guan; Fangying Ji; Yong Cheng; Zhuoyao Fang; Dexin Fang; Peng Yan; Qingkong Chen

    2013-01-01

    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 rele...

  3. Modification of Carboxymethyl Chitosan Film by Blending with Poly(benzyl L-glutamate)-block-poly(ethylene glycol) Copolymer

    A series of water-soluble carboxymethyl chitosan (CMCS)/poly(benzyl L-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) blend films with various CMCS/PBLG-b-PEG mol ratios were prepared by pervaporation method. Morphologies of CMCS/PBLG-b-PEG blend films were researched by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of CMCS/PBLG-b-PEG blend films were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests, and contact angle tests. It was revealed that the introduction of PBLG-b-PEG segments could greatly affect the morphology and the properties of CMCS films. (author)

  4. Properties study of poly(l-lactic acid) film modified by blending with flexible poly(tetramethylene glycol)

    A series of poly(L-lactic acid)/poly(tetramethylene glycol) (PLLA/PTMG) blend films were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLLA/PTMG blend films were investigated by scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PLLA/PTMG blend films were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile tests, and surface contact angle tests. It was revealed that the introduction of flexible PTMG could markedly modify the properties of the PLLA films. (author)

  5. Anomalously increased effective thermal conductivities of ethylene glycol-based nanofluids containing copper nanoparticles

    It is shown that a ''nanofluid'' consisting of copper nanometer-sized particles dispersed in ethylene glycol has a much higher effective thermal conductivity than either pure ethylene glycol or ethylene glycol containing the same volume fraction of dispersed oxide nanoparticles. The effective thermal conductivity of ethylene glycol is shown to be increased by up to 40% for a nanofluid consisting of ethylene glycol containing approximately 0.3 vol% Cu nanoparticles of mean diameter <10 nm. The results are anomalous based on previous theoretical calculations that had predicted a strong effect of particle shape on effective nanofluid thermal conductivity, but no effect of either particle size or particle thermal conductivity

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

    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.

  7. Synthesis and application of glycolic esters in methanol-gasoline as bifunctional additives

    To explore new and multifunctional additives for methanol-gasoline, glycolic esters were synthesized and screened as phase stabilizer and saturation vapor pressure depressor. The effect of the esters structure on the efficiency was discussed. It was found that the stability of the blends depend on the length of the glycolic esters' alkoxy group, and hexyl glycolic and octyl glycolic were found to be the most effective in various gasoline-methanol blends. Additionally, the glycolic esters can depress the saturation vapor pressure of methanol-gasoline effectively as well, and decyl glycolic is the most effective one. With these data, it can be concluded that the glycolic esters have the great potential to be used as bifunctional gasoline-methanol additives. (author)

  8. Cytocompatible Poly(ethylene glycol)-co-polycarbonate Hydrogels Crosslinked by Copper-free, Strain-promoted “Click” Chemistry

    Xu, Jianwen; Filion, Tera M.; Prifti, Fioleda; Song, Jie

    2011-01-01

    Strategies to encapsulate cells in cytocompatible 3-dimensional hydrogels with tunable mechanical properties and degradability without harmful gelling conditions are highly desired for regenerative medicine applications. Here we reported a method for preparing poly(ethylene glycol)-co-polycarbonate hydrogels through copper-free, strain-promoted azide-alkyne cycloaddition (SPAAC) “Click” chemistry. Hydrogels with varying mechanical properties were formed by “clicking” azido-functionalized poly...

  9. Conjugation of cell-penetrating peptides with poly(lactic-co-glycolic acid-polyethylene glycol nanoparticles improves ocular drug delivery

    Vasconcelos A

    2015-01-01

    Full Text Available Aimee Vasconcelos,1 Estefania Vega,2 Yolanda Pérez,3 María J Gómara,1 María Luisa García,2 Isabel Haro1 1Unit of Synthesis and Biomedical Applications of Peptides, Department of Biomedical Chemistry, Institute for Advanced Chemistry of Catalonia, Consejo Superior de Investigaciones Científicas (IQAC-CSIC, 2Department of Physical Chemistry, Institute of Nanoscience and Nanotechnology, Faculty of Pharmacy, University of Barcelona, 3Nuclear Magnetic Resonance Unit, IQAC-CSIC, Barcelona, Spain Abstract: 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

  10. Vapor Pressure of Aqueous Solutions of Ethylene Glycol

    Fujita, Toshihiko; Kikuchi, Sakae

    Vapor pressures of aqueous solutions of ethylene glycol are measured in the range of temperature from -10 to 60°C and concentration from 20 to 50wt%. In a low concentration range, the measured values of vapor pressure decrease according to the Raoult's law independent of temperature, while in a high concentration range, they show a trend to decrease towards the estimated values of freezing point with decreasing temperature. The following correlation equation is obtained for practical calculations on heating towers and the like. log(p/P0) = 5.351 - 6.4×10-4y + (1817 + 0.008y(y + 10))/(t + 240) where p, vapor perssure of aqueous solutions of ethylene glycol [kPa] ; P0, atmospheric pressure [=101.325kPa] ; y, concentration [wt%] ; t, temperature [°C].

  11. Thermal stability of collagen fibers in ethylene glycol.

    Miles, C A; Burjanadze, T V

    2001-03-01

    The mechanism that renders collagen molecules more stable when precipitated as fibers than the same molecules in solution is controversial. According to the polymer-melting mechanism the presence of a solvent depresses the melting point of the polymer due to a thermodynamic mechanism resembling the depression of the freezing point of a solvent due to the presence of a solute. On the other hand, according to the polymer-in-a-box mechanism, the change in configurational entropy of the collagen molecule on denaturation is reduced by its confinement by surrounding molecules in the fiber. Both mechanisms predict an approximately linear increase in the reciprocal of the denaturation temperature with the volume fraction (epsilon) of solvent, but the polymer-melting mechanism predicts that the slope is inversely proportional to the molecular mass of the solvent (M), whereas the polymer-in-a-box mechanism predicts a slope that is independent of M. Differential scanning calorimetry was used to measure the denaturation temperature of collagen in different concentrations of ethylene glycol (M = 62) and the slope found to be (7.29 +/- 0.37) x 10(-4) K(-1), compared with (7.31 +/- 0.42) x 10(-4) K(-1) for water (M = 18). This behavior was consistent with the polymer-in-a-box mechanism but conflicts with the polymer-melting mechanism. Calorimetry showed that the enthalpy of denaturation of collagen fibers in ethylene glycol was high, varied only slowly within the glycol volume fraction range 0.2 to 1, and fell rapidly at low epsilon. That this was caused by the disruption of a network of hydrogen-bonded glycol molecules surrounding the collagen is the most likely explanation. PMID:11222308

  12. The therapeutic value of glycolic acid peels in dermatology

    Grover C; Reddu B

    2003-01-01

    Chemical peeling or chemexfoliation has become increasingly popular in recent years for treatment of a number of cosmetic skin problems. Topical glycolic acid in the concentration of 10-30% for 3-5 minutes at fortnightly intervals was investigated as a therapeutic peeling agent in 41 patients having acne (39%), melasma (36.5%), post inflammatory hyperpigmentation (12%) and superficial scarring of varied etiology (12%). A final evaluation done at 16 weeks rev...

  13. Micropallet arrays with poly(ethylene glycol) walls†‡

    Wang, Yuli; Salazar, Georgina To'a; Pai, Jeng-Hao; Shadpour, Hamed; Sims, Christopher E.; Allbritton, Nancy L.

    2008-01-01

    Arrays of releasable micropallets with surrounding walls of poly(ethylene glycol) (PEG) were fabricated for the patterning and sorting of adherent cells. PEG walls were fabricated between the SU-8 pallets using a simple, mask-free strategy. By utilizing the difference in UV-transmittance of glass and SU-8, PEG monomer was selectively photopolymerized in the space surrounding the pallets. Since the PEG walls are composed of a cross-linked structure, the stability of the walls is independent of...

  14. Clickable Poly(ethylene glycol)-Microsphere-Based Cell Scaffolds

    Nguyen, Peter K.; Snyder, Christopher G.; Shields, Jason D.; Smith, Amanda W.; Elbert, Donald L.

    2013-01-01

    Clickable poly(ethylene glycol) (PEG) derivatives are used with two sequential aqueous two-phase systems to produce microsphere-based scaffolds for cell encapsulation. In the first step, sodium sulfate causes phase separation of the clickable PEG precursors and is followed by rapid geleation to form microspheres in the absence of organic solvent or surfactant. The microspheres are washed and then deswollen in dextran solutions in the presence of cells, producing tightly packed scaffolds that ...

  15. Multimeric, Multifunctional Derivatives of Poly(ethylene glycol

    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.

  16. Multimeric, Multifunctional Derivatives of Poly(ethylene glycol)

    Gian Maria Bonora; Francesca Cateni; Marina Zacchigna; Sara Drioli

    2011-01-01

    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.

  17. Polyethylene glycol-assisted transfection of Streptomyces protoplasts.

    Suarez, J E; Chater, K F

    1980-01-01

    In the presence of polyethylene glycol (concentration optimum 20%), protoplasts of appropriate Streptomyces strains could be transfected by deoxyribonucleic acid (DNA) of five temperate phages (phi C31, VP5, R4, phi 448, and S14) belonging to four different immunity groups. Quantitation of transfection was made possible by plating the transfection mixture with excess uninfected protoplasts in soft agar overlays on protoplast regeneration medium so that plaques were easily detected. Optimum fr...

  18. In vivo imaging of glycol chitosan-based nanogel biodistribution

    Pereira, Paula; Correia, Alexandra; Gama, F. M.

    2016-01-01

    The preclinical development of nanomedicines raises several challenges and requires a comprehensive characterization. Among them is the evaluation of the biodistribution following systemic administration. In previous work, the biocompatibility and in vitro targeting ability of a glycol chitosan (GC) based nanogel have been validated. In the present study, its biodistribution in the mice is assessed, using near-infrared (NIR) fluorescence imaging as a tool to track the nanogel over time, after...

  19. Preparation, Characterization and Performances of Powdered Polycarboxylate Superplasticizer with Bulk Polymerization

    Xiao Liu; Ziming Wang; Yunsheng Zheng; Suping Cui; Mingzhang Lan; Huiqun Li; Jie Zhu; Xu Liang

    2014-01-01

    A polycarboxylate superplasticizer (PCE) was synthesized in a non-solvent system with bulk polymerization and then was pulverized into powdered form to achieve a rapid transportation and convenient preparation. PCE synthesized by using isopentenyl polyethylene glycol (TPEG) or isobutenyl polyethylene glycol (IPEG) as a macromonomer exhibited the best fluidities and retaining properties at 80 °C and 75 °C, respectively. Besides, azobisisobutyronitrile (AIBN) was suitable as an initiator, and ...

  20. Instrument for benzene and toluene emission measurements of glycol regenerators

    We introduce an in-field and in-explosive atmosphere useable instrument, which can measure the benzene and toluene concentration in two gas and two glycol samples produced by natural gas dehydration units. It is a two-phase, on-line gas chromatograph with a photoacoustic spectroscopy based detector. The time resolution is 10 min per cycle and the minimum detectable concentrations are 2 mg m−3 for benzene, 3 mg m−3 for toluene in natural gas, and 5 g m−3 for benzene and 6 g m−3 for toluene in glycol. Test measurements were carried out at a dehydration plant belonging to MOL Hungarian Oil and Gas Company. Benzene and toluene emissions of gas dehydration unit are calculated from the measured values based on mass balance of a glycol regenerator. The relationship between the outdoor temperature and the measured concentration was observed which is caused by temperature-dependent operation of the whole dehydration unit. Emission decreases with increase of outdoor temperature. (paper)

  1. Glycolic acid peel therapy – a current review

    Sharad J

    2013-11-01

    Full Text Available Jaishree Sharad Skinfiniti Aesthetic Skin and Laser Clinic, Mumbai, India Abstract: Chemical peels have been time-tested and are here to stay. Alpha-hydroxy peels are highly popular in the dermatologist's arsenal of procedures. Glycolic acid peel is the most common alpha-hydroxy acid peel, also known as fruit peel. It is simple, inexpensive, and has no downtime. This review talks about various studies of glycolic acid peels for various indications, such as acne, acne scars, melasma, postinflammatory hyperpigmentation, photoaging, and seborrhea. Combination therapies and treatment procedure are also discussed. Careful review of medical history, examination of the skin, and pre-peel priming of skin are important before every peel. Proper patient selection, peel timing, and neutralization on-time will ensure good results, with no side effects. Depth of the glycolic acid peel depends on the concentration of the acid used, the number of coats applied, and the time for which it is applied. Hence, it can be used as a very superficial peel, or even a medium depth peel. It has been found to be very safe with Fitzpatrick skin types I–IV. All in all, it is a peel that is here to stay. Keywords: acne scar, melasma, photoaging, chemical peel, alpha-hydroxy peel

  2. 微波催化合成乙二醇单硬脂酸酯%Synthesis of glycol monostearate under Microwave Irradiation

    樊友

    2011-01-01

    Glycol monostearate was rapidly prepared by esterification of glycol with stearic acid in the presence of catalyst p - amino - benzenesulfonic acid under microwave irradiation. Effects of dosage of the catalyst, irradiation time, microwave power and molar ratio of glycol to stearic acid on the esterification was investigated. The optimum reaction conditions were glycol to stearic acid 1.1 : 1 ( moL/mol), dosage of catalyst 0.3 % ( wt), microwave power 800W, irradiation time 16 min.%在微波辐射条件下,以对氨基苯磺酸为催化剂,乙二醇和硬脂酸为原料合成了乙二醇单硬脂酸酯。考察了催化剂用量、微波辐射时间、微波功率和醇酸比对反应的影响。得出较佳反应条件为:乙二醇:硬脂酸为1.1:1(mol/mol)、催化剂用量0.3%(质量分数)、微波功率800W、反应时间16min。

  3. Biodegradable mucus-penetrating nanoparticles composed of diblock copolymers of polyethylene glycol and poly(lactic-co-glycolic acid)

    Yu, Tao; Wang, Ying-Ying; Yang, Ming; Schneider, Craig; Zhong, Weixi; Pulicare, Sarah; Choi, Woo-Jin; Mert, Olcay; Fu, Jie; Lai, Samuel K.; Hanes, Justin

    2012-01-01

    Mucus secretions coating entry points to the human body that are not covered by skin efficiently trap and clear conventional drug carriers, limiting controlled drug delivery at mucosal surfaces. To overcome this challenge, we recently engineered nanoparticles that readily penetrate a variety of human mucus secretions, which we termed mucus-penetrating particles (MPP). Here, we report a new biodegradable MPP formulation based on diblock copolymers of poly(lactic-co-glycolic acid) and poly(ethy...

  4. Polyethylene glycol coated CoFe2O4 nanoparticles: A potential spinel ferrite for biomedical applications

    The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe2O4) nanoparticles have been reported in the present study. CoFe2O4 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 CoFe2O4 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 CoFe2O4 nanoparticles were calculated by using XRD data. The presence of PEG on CoFe2O4 nanoparticles and reduced agglomeration in the CoFe2O4 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

  5. Polyethylene glycol coated CoFe{sub 2}O{sub 4} nanoparticles: A potential spinel ferrite for biomedical applications

    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.

  6. Hepatocyte-targeting gene transfer mediated by galactosylated poly(ethylene glycol)-graft-polyethylenimine derivative.

    Wang, Yuqiang; Su, Jing; Cai, Wenwei; Lu, Ping; Yuan, Lifen; Jin, Tuo; Chen, Shuyan; Sheng, Jing

    2013-01-01

    Biscarbamate cross-linked polyethylenimine derivative (PEI-Et) has been reported as a novel nonviral vector for efficient and safe gene transfer in our previous work. However, it had no cell-specificity. To achieve specific delivery of genes to hepatocytes, galactosylated poly(ethylene glycol)-graft-polyethylenimine derivative (GPE) was prepared through modification of PEI-Et with poly(ethylene glycol) and lactobionic acid, bearing a galactose group as a hepatocyte-targeting moiety. The composition of GPE was characterized by proton nuclear magnetic resonance. The weight-average molecular weight of GPE measured with a gel permeation chromatography instrument was 9489 Da, with a polydispersity of 1.44. GPE could effectively condense plasmid DNA (pDNA) into nanoparticles. Gel retardation assay showed that GPE/pDNA complexes were completely formed at weigh ratios (w/w) over 3. The particle size of GPE/pDNA complexes was 79-100 nm and zeta potential was 6-15 mV, values which were appropriate for cellular uptake. The morphology of GPE/pDNA complexes under atomic force microscopy appeared spherical and uniform in size, with diameters of 53-65 nm. GPE displayed much higher transfection efficiency than commercially available PEI 25 kDa in BRL-3A cell lines. Importantly, GPE showed good hepatocyte specificity. Also, the polymer exhibited significantly lower cytotoxicity compared to PEI 25 kDa at the same concentration or weight ratio in BRL-3A cell lines. To sum up, our results indicated that GPE might carry great potential in safe and efficient hepatocyte-targeting gene delivery. PMID:23576866

  7. Tumor targetability and antitumor effect of docetaxel-loaded hydrophobically modified glycol chitosan nanoparticles.

    Hwang, Ho-Young; Kim, In-San; Kwon, Ick Chan; Kim, Yong-Hee

    2008-05-22

    Hydrophobically modified glycol chitosan (HGC) nanoparticles, a new nano-sized drug carrier, were prepared by introducing a hydrophobic molecule, cholanic acid, to water soluble glycol chitosan. The HGC nanoparticles were easily loaded with the anticancer drug docetaxel (DTX) using a dialysis method, and the resulting docetaxel-loaded HGC (DTX-HGC) nanoparticles formed spontaneously self-assembled aggregates with a mean diameter of 350 nm in aqueous condition. The DTX-HGC nanoparticles were well dispersed and stable for 2 weeks under physiological conditions (pH 7.4 and 37 degrees C) and a sustained drug release profile, in vitro. In addition, the DTX-HGC nanoparticles were reasonably stable in the presence of excess bovine serum albumin, which suggested that the DTX-HGC nanoparticles might also be stable in the blood stream. The DTX-HGC nanoparticles exhibited a distinctive deformability in aqueous conditions, in that they could easily pass through a filter membrane with 200 nm pores despite their mean diameter of 350 nm. We also evaluated the time-dependent excretion profile, in vivo biodistribution, prolonged circulation time, and tumor targeting ability of DTX-HGC nanoparticles by using a non-invasive live animal imaging technology. Finally, under optimal conditions for cancer therapy, the DTX-HGC nanoparticles showed higher antitumor efficacy such as reduced tumor volume and increased survival rate in A549 lung cancer cells-bearing mice and strongly reduced the anticancer drug toxicity compared to that of free DTX in tumor-bearing mice. Together our results showed that the anticancer loaded nano-sized drug carriers are a promising nano-sized drug formulation for cancer therapy. PMID:18374444

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

    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

  9. A Novel Synthesis Method of Porous Calcium Silicate Hydrate Based on the Calcium Oxide/Polyethylene Glycol Composites

    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.

  10. Studies of miscibility and specific interactions of antitumor-active anhydride copolymer and poly(ethylene glycol) blends.

    Can, Hatice Kaplan; Parvizikhosroshahi, Shahed; Uluışık, Erdem C

    2016-01-01

    The blending of polymers is of great interest, since the modification gives rise to diverse physical properties with the functionality of a polymer, without synthesis. Water-soluble antitumor-active poly(maleic anhydride-alt-acrylic acid) poly(MA-alt-AA) and poly(ethylene glycol) (PEG) blends were prepared by casting, and compatible properties were investigated by dilute solution viscometry. Viscosity measurements were made on ternary systems of polymer (1)/polymer (2)/solvent (H2O) and p-dioxane, at different concentrations of PEG and poly(MA-alt-AA). The interaction parameters Δβ, μ, Δk, Δb, β and α, which have been proposed, have been obtained using the viscosity data, to probe the miscibility of the polymer blends. The solid blends prepared were characterized with ATR-FTIR, (1)H-NMR, DTA and TGA. PMID:25406735

  11. The influence of nanotexturing of poly(lactic-co-glycolic acid) films upon human ovarian cancer cell attachment

    Yaşayan, Gökçen; Xue, Xuan; Collier, Pamela; Clarke, Philip; Alexander, Morgan R.; Marlow, Maria

    2016-06-01

    In this study, we have produced nanotextured poly(lactic-co-glycolic acid) (PLGA) films by using polystyrene (PS) particles as a template to make a polydimethylsiloxane mould against which PLGA is solvent cast. Biocompatible, biodegradable and nanotextured PLGA films were prepared with PS particles of diameter of 57, 99, 210, and 280 nm that produced domes of the same dimension in the PLGA surface. The effect of the particulate monolayer templating method was investigated to enable preparation of the films with uniformly ordered surface nanodomes. Cell attachment of a human ovarian cancer cell line (OVCAR3) alone and co-cultured with mesenchymal stem cells (MSCs) was evaluated on flat and topographically nano-patterned surfaces. Cell numbers were observed to increase on the nanotextured surfaces compared to non-textured surfaces both with OVCAR3 cultures and OVCAR3-MSC co-cultures at 24 and 48 h time points.

  12. Cholesteryl n-monomethoxypoly(ethylene glycol)-succinate-l-phenylalanine:synthesis and effect on liposomes

    Yang, Won Young; Lee, Youn Sik [Chonbuk National Univ., Chonju (Korea, Republic of); Lee, Sang Hee [Kunsan National Univ., Kunsan (Korea, Republic of); Lee, Eun Ok; Chung, Guk Hoon [Bio-Chem BG. Biotech., Yongin (Korea, Republic of)

    2002-01-01

    Poly(ethylene glycol)-phosphatidylethanolamine conjugate (PEG-PE) has been used in preparing long-circulating liposomes. As a substitute for PEG-PE which can also be used in the long-circulating liposome formualtions, but can be prepared more readily with a lower cost, PEG-Phe-Chol was synthesized from PEG, phenylalanine, and cholesterol. The addition of the PEG derivative to distearoylphosphatidylcholine (DSPC) led to the formation of mixed micelles as well as liposomes when the derivative content was 10 mol % or greater. On the other hand, the addition of just 5 mol % PEG-Phe-Chol to dioleoylphosphatidylethanolamine(DOPE) generated mixed micelles as well as liposomes, but the formation of mixed micelles was completely inhibited by the addition of cholesterol. The leakage of entrapped calcein out of DOPE/cholesterol (7/3) liposomes containing 5 mol % PEG-Phe-Chol was about 45 % during the incubation time for 24 h in 50 % rabbit plasma, which was similar to that of the same liposomes containing 5 mol % PEG-dipalmitoylphosphatidyl-ethanolamine (DPPE) under the identical conditions.

  13. Nanostructured medical device coatings based on self-assembled poly(lactic-co-glycolic acid) nanoparticles

    Here we present a new method for providing nanostructured drug-loaded polymer films which enable control of film surface morphology and delivery of therapeutic agents. Silicon wafers were employed as models for implanted biomaterials and poly(lactic-co-glycolic acid) (PLGA) nanoparticles were assembled onto the silicon surface by electrostatic interaction. Monolayers of the PLGA particles were deposited onto the silicon surface upon incubation in an aqueous particle suspension. Particle density and surface coverage of the silicon wafers were varied by altering particle concentration, incubation time in nanoparticle suspension and ionic strength of the suspension. Dye loaded nanoparticles were prepared and assembled to silicon surface to form nanoparticle films. Fluorescence intensity measurements showed diffusion-controlled release of the dye over two weeks and atomic force microscopy (AFM) analysis revealed that these particles remained attached to the surface during the incubation time. This work suggests that coating implants with PLGA nanoparticles is a versatile technique which allows drug release from the implant surface and modulation of surface morphology. - Highlights: • Mono-layer PLGA nanoparticle coatings were fabricated on silicon wafers by electrostatic interactions. • Surface coverage with the particles (coating morphology) was varied by changing preparation parameters. • The coatings were loaded with fluorescence dye and this was released in PBS. • The coatings have the potential to alter surface morphology in nanorange and release biomolecules

  14. Bioactive Nanocomposite Poly (Ethylene Glycol) Hydrogels Crosslinked by Multifunctional Layered Double Hydroxides Nanocrosslinkers.

    Huang, Heqin; Xu, Jianbin; Wei, Kongchang; Xu, Yang J; Choi, Chun Kit K; Zhu, Meiling; Bian, Liming

    2016-07-01

    Poly (ethylene glycol) (PEG) based hydrogels have been widely used in many biomedical applications such as regenerative medicine due to their good biocompatibility and negligible immunogenicity. However, bioactivation of PEG hydrogels, such as conjugation of bioactive biomolecules, is usually necessary for cell-related applications. Such biofunctionalization of PEG hydrogels generally involves complicated and time-consuming bioconjugation procedures. Herein, we describe the facile preparation of bioactive nanocomposite PEG hydrogel crosslinked by the novel multifunctional nanocrosslinkers, namely polydopamine-coated layered double hydroxides (PD-LDHs). The catechol-rich PD-LDH nanosheets not only act as effective nanocrosslinkers reinforcing the mechanical strength of the hydrogel, but also afford the hydrogels with robust bioactivity and bioadhesion via the cortical-mediated couplings. The obtained nanocomposite PEG hydrogels with the multifunctional PD-LDH crosslinking domains show tunable mechanical properties, self-healing ability, and bioadhesion to biological tissues. Furthermore, these hydrogels also promote the sequestration of proteins and support the osteogenic differentiation of human mesenchymal stem cells without any further bio-functionalization. Such facile preparation of bioactive and bioadhesive PEG hydrogels have rarely been achieved and may open up a new avenue for the design of nanocomposite PEG hydrogels for biomedical applications. PMID:27061462

  15. Preparation and characterization of injectable calcium phosphate cement paste modified by polyethylene glycol-6000

    Chen Fangping, E-mail: chenfangping06@yahoo.com.cn [The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Liu Changsheng, E-mail: liucs@ecust.edu.cn [The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Wei Jie [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen Xiao; Zhao Zhen; Gao Yanli [Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

    2011-02-15

    An ICPC with high structure recoverability and paste stability was successfully developed directly incorporating PEG-6000 into the liquid phase of CPC. The rheological behavior of ICPC was investigated with rheometric scientific ARES902-30004 controlled strain rheometer. Novel approaches of flow rate, shear thinning index (SI), shear stress slowdown ({Delta}{tau}) and thixotropy loop area have been applied to assess the injectability and structure recoverability of the ICPC paste. The addition of PEG-6000 to ICPC resulted in a thixotrophic structure with shortened setting time, slightly increased viscosity, larger thixotropic hysteresis loop area and lower {Delta}{tau}, with the improvement largely dependent on the PEG-6000 content. With acceptable injectability and shortened setting time, ICPC (1%) showed the lowest {Delta}{tau} and the highest SI, endowing the paste good structure recoverability and paste stability. The ICPC (1%) was bioactive and facilitated cell attachment and proliferation. The optimized ICPC (1%) paste with a relatively good structure stability and paste stability may serve as a good candidate for tooth root-canal fillings and percutaneous vertebroplasty in microinvasive surgery.

  16. Preparation and characterization of injectable calcium phosphate cement paste modified by polyethylene glycol-6000

    An ICPC with high structure recoverability and paste stability was successfully developed directly incorporating PEG-6000 into the liquid phase of CPC. The rheological behavior of ICPC was investigated with rheometric scientific ARES902-30004 controlled strain rheometer. Novel approaches of flow rate, shear thinning index (SI), shear stress slowdown (Δτ) and thixotropy loop area have been applied to assess the injectability and structure recoverability of the ICPC paste. The addition of PEG-6000 to ICPC resulted in a thixotrophic structure with shortened setting time, slightly increased viscosity, larger thixotropic hysteresis loop area and lower Δτ, with the improvement largely dependent on the PEG-6000 content. With acceptable injectability and shortened setting time, ICPC (1%) showed the lowest Δτ and the highest SI, endowing the paste good structure recoverability and paste stability. The ICPC (1%) was bioactive and facilitated cell attachment and proliferation. The optimized ICPC (1%) paste with a relatively good structure stability and paste stability may serve as a good candidate for tooth root-canal fillings and percutaneous vertebroplasty in microinvasive surgery.

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

    Wöhl-Bruhn, Stefanie; Bertz, Andreas; Kuntsche, Judith; Menzel, Henning; Bunjes, Heike

    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...

  18. Density and vapour pressure of mixed-solvent desiccant systems (propylene glycol or dipropylene glycol or tripropylene glycol + magnesium chloride + water)

    In this present work, new experimental data for density and vapour pressure of the mixed-solvent desiccant systems containing {40 wt% glycol (propylene or dipropylene or tripropylene) + (4 or 9 or 16 wt%) magnesium chloride salt + water} were reported for temperatures up to 343.15 K at normal atmospheric condition. The density and vapour pressure data obtained are presented as a function of temperature and composition. An empirical equation was used to correlate the temperature and compositional dependence of the density values. A model based on the mean spherical approximation for aqueous electrolyte solutions incorporating the pseudo-solvent approach was used to represent the vapour pressure as a function of temperature and composition. Satisfactory results were obtained for both density and vapour pressure calculations

  19. Alpha-tocopheryl polyethylene glycol succinate-emulsified poly(lactic-co-glycolic acid) nanoparticles for reversal of multidrug resistance in vitro

    Wang, Ying; Guo, Miao; Lu, Yu; Ding, Li-Ying; Ron, Wen-Ting; Liu, Ya-Qing; Song, Fei-Fei; Yu, Shu-Qin

    2012-12-01

    Multidrug resistance (MDR) is one of the factors in the failure of anticancer chemotherapy. In order to enhance the anticancer effect of P-glycoprotein (P-gp) substrates, inhibition of the P-gp efflux pump on MDR cells is a good tactic. We designed novel multifunctional drug-loaded alpha-tocopheryl polyethylene glycol succinate (TPGS)/poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TPGS/PLGA/SN-38 NPs; SN-38 is 7-ethyl-10-hydroxy-camptothecin), with TPGS-emulsified PLGA NPs as the carrier and modulator of the P-gp efflux pump and SN-38 as the model drug. TPGS/PLGA/SN-38 NPs were prepared using a modified solvent extraction/evaporation method. Physicochemical characterizations of TPGS/PLGA/SN-38 NPs were in conformity with the principle of nano-drug delivery systems (nDDSs), including a diameter of about 200 nm, excellent spherical particles with a smooth surface, narrow size distribution, appropriate surface charge, and successful drug-loading into the NPs. The cytotoxicity of TPGS/PLGA/SN-38 NPs to MDR cells was increased by 3.56 times compared with that of free SN-38. Based on an intracellular accumulation study relative to the time-dependent uptake and efflux inhibition, we suggest novel mechanisms of MDR reversal of TPGS/PLGA NPs. Firstly, TPGS/PLGA/SN-38 NPs improved the uptake of the loaded drug by clathrin-mediated endocytosis in the form of unbroken NPs. Simultaneously, intracellular NPs escaped the recognition of P-gp by MDR cells. After SN-38 was released from TPGS/PLGA/SN-38 NPs in MDR cells, TPGS or/and PLGA may modulate the efflux microenvironment of the P-gp pump, such as mitochondria and the P-gp domain with an ATP-binding site. Finally, the controlled-release drug entered the nucleus of the MDR cell to induce cytotoxicity. The present study showed that TPGS-emulsified PLGA NPs could be functional carriers in nDDS for anticancer drugs that are also P-gp substrates. More importantly, to enhance the therapeutic effect of P-gp substrates, this work

  20. Alpha-tocopheryl polyethylene glycol succinate-emulsified poly(lactic-co-glycolic acid) nanoparticles for reversal of multidrug resistance in vitro

    Multidrug resistance (MDR) is one of the factors in the failure of anticancer chemotherapy. In order to enhance the anticancer effect of P-glycoprotein (P-gp) substrates, inhibition of the P-gp efflux pump on MDR cells is a good tactic. We designed novel multifunctional drug-loaded alpha-tocopheryl polyethylene glycol succinate (TPGS)/poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TPGS/PLGA/SN-38 NPs; SN-38 is 7-ethyl-10-hydroxy-camptothecin), with TPGS-emulsified PLGA NPs as the carrier and modulator of the P-gp efflux pump and SN-38 as the model drug. TPGS/PLGA/SN-38 NPs were prepared using a modified solvent extraction/evaporation method. Physicochemical characterizations of TPGS/PLGA/SN-38 NPs were in conformity with the principle of nano-drug delivery systems (nDDSs), including a diameter of about 200 nm, excellent spherical particles with a smooth surface, narrow size distribution, appropriate surface charge, and successful drug-loading into the NPs. The cytotoxicity of TPGS/PLGA/SN-38 NPs to MDR cells was increased by 3.56 times compared with that of free SN-38. Based on an intracellular accumulation study relative to the time-dependent uptake and efflux inhibition, we suggest novel mechanisms of MDR reversal of TPGS/PLGA NPs. Firstly, TPGS/PLGA/SN-38 NPs improved the uptake of the loaded drug by clathrin-mediated endocytosis in the form of unbroken NPs. Simultaneously, intracellular NPs escaped the recognition of P-gp by MDR cells. After SN-38 was released from TPGS/PLGA/SN-38 NPs in MDR cells, TPGS or/and PLGA may modulate the efflux microenvironment of the P-gp pump, such as mitochondria and the P-gp domain with an ATP-binding site. Finally, the controlled-release drug entered the nucleus of the MDR cell to induce cytotoxicity. The present study showed that TPGS-emulsified PLGA NPs could be functional carriers in nDDS for anticancer drugs that are also P-gp substrates. More importantly, to enhance the therapeutic effect of P-gp substrates, this work

  1. Structure and thermal performance of poly(ethylene glycol) alkyl ether (Brij)/porous silica (MCM-41) composites as shape-stabilized phase change materials

    Graphical abstract: The maximum 50 wt% Brij58 is loaded into the porous MCM-41 networks, and a new peak at 18.8° in XRD patterns confirmed the changes of crystallization behavior of Brij58 against the bulk one. - Highlights: • Poly(ethylene glycol) hexadecyl ether and poly(ethylene glycol) octadecyl ether have the good thermal storage ability. • New peak at 18.8° proved the coexisted confined crystallization and nucleation-induced crystallization. • Poly(ethylene glycol) alkyl ether/MCM-41 PCMs exhibits the good thermal stability. - Abstract: A series of shape-stabilized phase change materials (PCMs), composed of poly(ethylene glycol) hexadecyl ether (Brij58) or poly(ethylene glycol) octadecyl ether (Brij76) and porous silica (MCM-41), were prepared by the physical mixing method. The structure, thermal stability, energy storage ability and crystallization behavior of these composites are deeply investigated and characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and thermogravimetric analysis (TGA). Obvious phase transition behavior and energy storage capability are observed for these Brij/MCM-41 composites, and the heat storage efficiency increased with the weight of Brij component. New peak at 18.8° demonstrated that the pore size and the surface adsorption ability of MCM-41 affect the crystallization behavior of Brij molecule. The crystalline structure and energy storage ability of these Brij/MCM-41 composites are discussed based on the crystallization process

  2. Structure and thermal performance of poly(ethylene glycol) alkyl ether (Brij)/porous silica (MCM-41) composites as shape-stabilized phase change materials

    Zhang, Lingjian; Shi, Haifeng, E-mail: haifeng.shi@gmail.com; Li, Weiwei; Han, Xu; Zhang, Xingxiang, E-mail: zhangpolyu@gmail.com

    2013-10-20

    Graphical abstract: The maximum 50 wt% Brij58 is loaded into the porous MCM-41 networks, and a new peak at 18.8° in XRD patterns confirmed the changes of crystallization behavior of Brij58 against the bulk one. - Highlights: • Poly(ethylene glycol) hexadecyl ether and poly(ethylene glycol) octadecyl ether have the good thermal storage ability. • New peak at 18.8° proved the coexisted confined crystallization and nucleation-induced crystallization. • Poly(ethylene glycol) alkyl ether/MCM-41 PCMs exhibits the good thermal stability. - Abstract: A series of shape-stabilized phase change materials (PCMs), composed of poly(ethylene glycol) hexadecyl ether (Brij58) or poly(ethylene glycol) octadecyl ether (Brij76) and porous silica (MCM-41), were prepared by the physical mixing method. The structure, thermal stability, energy storage ability and crystallization behavior of these composites are deeply investigated and characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and thermogravimetric analysis (TGA). Obvious phase transition behavior and energy storage capability are observed for these Brij/MCM-41 composites, and the heat storage efficiency increased with the weight of Brij component. New peak at 18.8° demonstrated that the pore size and the surface adsorption ability of MCM-41 affect the crystallization behavior of Brij molecule. The crystalline structure and energy storage ability of these Brij/MCM-41 composites are discussed based on the crystallization process.

  3. Anaerobic Biodegradation of Ethylene Glycol within Hydraulic Fracturing Fluid

    Heyob, K. M.; Mouser, P. J.

    2014-12-01

    Ethylene glycol (EG) is a commonly used organic additive in hydraulic fracturing fluids used for shale gas recovery. Under aerobic conditions, this compound readily biodegrades to acetate and CO2 or is oxidized through the glycerate pathway. In the absence of oxygen, organisms within genera Desulfovibrio, Acetobacterium, and others can transform EG to acetaldehyde, a flammable and suspected carcinogenic compound. Acetaldehyde can then be enzymatically degraded to ethanol or acetate and CO2. However, little is known on how EG degrades in the presence of other organic additives, particularly under anaerobic conditions representative of deep groundwater aquifers. To better understand the fate and attenuation of glycols within hydraulic fracturing fluids we are assessing their biodegradation potential and pathways in batch anaerobic microcosm treatments. Crushed Berea sandstone was inoculated with groundwater and incubated with either EG or a synthetic fracturing fluid (SFF) containing EG formulations. We tracked changes in dissolved organic carbon (DOC), EG, and its transformation products over several months. Approximately 41% of bulk DOC in SFF is degraded within 21 days, with 58% DOC still remaining after 63 days. By comparison, this same SFF degrades by 70% within 25 days when inoculated with sediment-groundwater microbial communities, suggesting that bulk DOC degradation occurs at a slower rate and to a lesser extent with bedrock. Aerobic biodegradation of EG occurs rapidly (3-7 days); however anaerobic degradation of EG is much slower, requiring several weeks for substantial DOC loss to be observed. Ongoing experiments are tracking the degradation pathways of EG alone and in the presence of SFF, with preliminary data showing incomplete glycol transformation within the complex hydraulic fracturing fluid mixture. This research will help to elucidate rates, processes, and pathways for EG biodegradation and identify key microbial taxa involved in its degradation.

  4. Evaluation of an Industrial Byproduct Glycol Mixture as a Carbon Source for Denitrification

    Liang, Wei

    2013-01-01

    In order to meet increasingly stringent total nitrogen limits, supplemental carbon must be added to improve the performance of the biological nutrient removal process. An industrial by-product that contained ethylene glycol and propylene glycol was used as a substitute carbon source for methanol in this study. The objectives of this study were to investigate the efficiency of using the glycol mixture as carbon source, including the calculation of denitrification rate and yield at two differen...

  5. The Soret effect of mono-, di- and tri-glycols in ethanol

    Klein, M.; Wiegand, S.

    2011-01-01

    We employed thermal diffusion forced Rayleigh scattering (TDFRS) to investigate the chain length dependence of the thermal diffusion behavior of short glycols in ethanol. We studied three glycols, monoethylenglycol (MEG), diethylenglycol (DEG) and triethylenglycol (TEG), in an ethanol solution. In contrast to the polymer polyethylenglycol, the shorter glycols used within the framework of this study are completely soluble in ethanol, at least for low molar fractions. In order to guarantee a go...

  6. Glycol methacrylate in light microscopy: nucleic acid cytochemistry.

    Cole, M B; Ellinger, J

    1981-07-01

    Techniques utilizing Feulgen, azure B bromide, methyl green-pyronin, gallocyanin chromalum and cresyl violet stains have been modified and adapted for visualizing nucleic acids in 0.5-2.0 micrometer sections of tissues embedded in glycol methacrylate (GMA). Methods for evaluating the stain specificity for DNA and RNA using deoxyribonuclease and ribonuclease digestions, aldehyde blocking, and acid extractions are also described. The specificity of the stains in GMA embedded tissues is comparable to that reported for paraffin-embedded tissues. PMID:6167720

  7. Capture and utilization of carbon dioxide with polyethylene glycol

    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

  8. The therapeutic value of glycolic acid peels in dermatology

    Grover C

    2003-03-01

    Full Text Available Chemical peeling or chemexfoliation has become increasingly popular in recent years for treatment of a number of cosmetic skin problems. Topical glycolic acid in the concentration of 10-30% for 3-5 minutes at fortnightly intervals was investigated as a therapeutic peeling agent in 41 patients having acne (39%, melasma (36.5%, post inflammatory hyperpigmentation (12% and superficial scarring of varied etiology (12%. A final evaluation done at 16 weeks revealed that this modality is useful especially in superficial scarring and melasma, moderately successful in acne patients with no response in dermal pigmentation. No significant untoward effects were seen.

  9. Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid

    The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

  10. Direct analysis in real time-mass spectrometry (DART-MS) for rapid qualitative screening of toxic glycols in glycerin-containing products.

    Self, Randy L

    2013-06-01

    In 2007, the United States Food and Drug Administration released guidance recommending testing of glycerin used in regulated consumer products, such as cough syrup preparations, toothpaste, and other pharmaceutical and food products, for the toxic compounds ethylene glycol and diethylene glycol. Regulatory laboratories routinely test glycerin, and products containing glycerin or related compounds for these toxic glycols, using an official gas chromatographic method, to ensure the safety of these products. The current work describes a companion technique to compliment this GC-FID method utilizing Orbitrap mass spectrometry with direct analysis in real time ionization to rapidly screen these samples qualitatively, with results in as little as five seconds, with no sample preparation required. This allows the more time and resource intensive method to be reserved for those rare cases when these compounds are detected, potentially greatly improving laboratory efficiency. The technique was evaluated for qualitative sensitivity and repeatability, and compared against the GC-FID method. The method appears to perform well against these metrics. PMID:23584076

  11. Mode of Action: Oxalate Crystal-Induced Renal Tubule Degeneration and Glycolic Acid-Induced Dysmorphogenesis—Renal and Developmental Effects of Ethylene Glycol

    Corley, Rick A.; Meek, M E.; Carney, E W.

    2005-10-01

    Ethylene glycol can cause both renal and developmental toxicity, with metabolism playing a key role in the mode of action (MOA) for each form of toxicity. Renal toxicity is ascribed to the terminal metabolite oxalic acid, which precipitates in the kidney in the form of calcium oxalate crystals and is believed to cause physical damage to the renal tubules. The human relevance of the renal toxicity of ethylene glycol is indicated by the similarity between animals and humans of metabolic pathways, the observation of renal oxalate crystals in toxicity studies in experimental animals and human poisonings, and cases of human kidney and bladder stones related to dietary oxalates and oxalate precursors. High-dose gavage exposures to ethylene glycol also cause axial skeletal defects in rodents (but not rabbits), with the intermediary metabolite, glycolic acid, identified as the causative agent. However, the mechanism by which glycolic acid perturbs development has not been investigated sufficiently to develop a plausible hypothesis of mode of action, nor have any cases of ethylene glycol-induced developmental effects been reported in humans. Given this, and the variations in sensitivity between animal species in response, the relevance to humans of ethylene glycol-induced developmental toxicity in animals is unknown at this time.

  12. Design and formulation of nanoemulsions using 2-(poly(hexafluoropropylene oxide)) perfluoropropyl benzene in combination with linear perfluoro(polyethylene glycol dimethyl ether).

    Mountain, Gregory A; Jelier, Benson J; Bagia, Christina; Friesen, Chadron M; Janjic, Jelena M

    2014-06-01

    This is the first report where PFPAE aromatic conjugates and perfluoro(polyethylene glycol dimethyl ether) are combined and formulated as nanoemulsions with droplet size below 100 nm. A perfluoropolyalkylether (PFPAE) aromatic conjugate, 2-(poly(hexafluoropropylene oxide)) perfluoropropyl benzene, was used as fluorophilic-hydrophilic diblock (FLD) aimed at stabilizing perfluoro(polyethylene glycol dimethyl ether) nanoemulsions. Its effects on colloidal behaviors in triphasic (organic/fluorous/aqueous) nanoemulsions were studied. The addition of FLD construct to fluorous phase led to decrease in PFPAE nanoemulsion droplet size to as low as 85 nm. Prepared nanoemulsions showed high colloidal stability. Our results suggest that these materials represent viable novel approach to fluorous colloid systems design with potential for biomedical and synthetic applications. PMID:24976645

  13. Backfilling-Free Strategy for Biopatterning on Intrinsically Dual-Functionalized Poly[2-Aminoethyl Methacrylate-co-Oligo(Ethylene Glycol) Methacrylate] Films.

    Lee, Bong Soo; Lee, Juno; Han, Gyeongyeop; Ha, EunRae; Choi, Insung S; Lee, Jungkyu K

    2016-07-20

    We demonstrated protein and cellular patterning with a soft lithography technique using poly[2-aminoethyl methacrylate-co-oligo(ethylene glycol) methacrylate] films on gold surfaces without employing a backfilling process. The backfilling process plays an important role in successfully generating biopatterns; however, it has potential disadvantages in several interesting research and technical applications. To overcome the issue, a copolymer system having highly reactive functional groups and bioinert properties was introduced through a surface-initiated controlled radical polymerization with 2-aminoethyl methacrylate hydrochloride (AMA) and oligo(ethylene glycol) methacrylate (OEGMA). The prepared poly(AMA-co-OEGMA) film was fully characterized, and among the films having different thicknesses, the 35 nm-thick biotinylated, poly(AMA-co-OEGMA) film exhibited an optimum performance, such as the lowest nonspecific adsorption and the highest specific binding capability toward proteins. PMID:27252120

  14. Effect of addition of poly(ethylene glycol) on electrical conductivity of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)hybrid

    WANG Tiejun; QI Yingqun; XU Jingkun; HU Xiujie; CHEN Ping

    2003-01-01

    By mixing various concentrations of poly (ethylene glycol), a series of poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate) composite thin films were prepared. The electrical conductivity of the PEDOT-PSS/PEG thin films was measured by the four-probe method. Experimental results showed that the inclusion of poly(ethylene glycol) influenced the electrical conductivity of PEDOT-PSS film significantly. With the increase of PEG concentrations, the electrical conductivity sharply increased to reach a maximum and then slowly decreased down. Furthermore, the PEG molecular weight and environment temperature also played important roles on the electrical conductivity of PEDOT-PSS/PEG thin films. A good linear relationship was found between ln -DC and T -1/2 within the entire temperature range detected.

  15. Ethylene glycol-mediated synthesis of nanoporous anatase TiO{sub 2} rods and rutile TiO{sub 2} self-assembly chrysanthemums

    Li Quanjun [State Key Laboratory of Superhard Materials, Jilin University, Qianwei Road, Changchun 130012 (China); Liu Bingbing [State Key Laboratory of Superhard Materials, Jilin University, Qianwei Road, Changchun 130012 (China)], E-mail: liubb@jlu.edu.cn; Li Yingai; Liu Ran; Li Xianglin; Li Dongmei; Yu Shidan; Liu Dedi; Wang Peng; Li Bing; Zou Bo; Cui Tian; Zou Guangtian [State Key Laboratory of Superhard Materials, Jilin University, Qianwei Road, Changchun 130012 (China)

    2009-03-05

    Nanoporous anatase TiO{sub 2} rods and rutile TiO{sub 2} chrysanthemums were successfully synthesized via a simple ethylene glycol-mediated synthesis route. Their morphologies, phase compositions and components were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman and IR, respectively. The results show that a self-assembly growth takes place in the calcination under vacuum, which makes the titanium glycolate rods transform into rutile TiO{sub 2}/C chrysanthemums rather than anatase TiO{sub 2} rods. It also indicates that the carbon plays an important role in the phase transition process which promotes the phase transition to rutile TiO{sub 2} at a lower temperature (400 deg. C). It provides a new approach to prepare nanoporous rutile TiO{sub 2} nanomaterials under low temperature.

  16. Ethylene glycol-mediated synthesis of nanoporous anatase TiO2 rods and rutile TiO2 self-assembly chrysanthemums

    Nanoporous anatase TiO2 rods and rutile TiO2 chrysanthemums were successfully synthesized via a simple ethylene glycol-mediated synthesis route. Their morphologies, phase compositions and components were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman and IR, respectively. The results show that a self-assembly growth takes place in the calcination under vacuum, which makes the titanium glycolate rods transform into rutile TiO2/C chrysanthemums rather than anatase TiO2 rods. It also indicates that the carbon plays an important role in the phase transition process which promotes the phase transition to rutile TiO2 at a lower temperature (400 deg. C). It provides a new approach to prepare nanoporous rutile TiO2 nanomaterials under low temperature

  17. Crystal structure and thermal property of polyethylene glycol octadecyl ether

    Highlights: ► The crystal structure of C18En for n ≥ 20 is a monoclinic system. ► Polyethylene glycol octadecyl ether crystallizes perfectly. ► The number of repeat units has significant effect on the melting, crystallizing temperature and enthalpy. ► The thermal stable temperature increases rapidly with increasing the number of repeat unit. - Abstract: The crystal structure, phase change property and thermal stable temperature (Td) of polyethylene glycol octadecyl ether [HO(CH2CH2O)nC18H37, C18En] with various numbers of repeat units (n = 2, 10, 20 and 100) as phase change materials (PCMs) were investigated using temperature variable Fourier transformed infrared spectroscopy (FTIR), wide-angle X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). C18En crystallizes perfectly at 0 °C; and the crystal structure for n ≥ 20 is a monoclinic system. The number of repeat units has great effect on the phase change properties of C18En. The thermal stable temperature increases rapidly with increasing the number of repeat units. They approach to that of PEG-2000 as the number of repeat units is more than 10. Td increases rapidly with increasing the number of repeat units. C18En are a series of promising polymeric PCMs

  18. Crystal structure and thermal property of polyethylene glycol octadecyl ether

    Meng, Jie-yun; Tang, Xiao-fen; Li, Wei; Shi, Hai-feng [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, School of Material Science and Engineering, Tianjin Polytechnic University, Tianjin 300387 (China); Zhang, Xing-xiang, E-mail: zhangpolyu@yahoo.com.cn [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, School of Material Science and Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

    2013-04-20

    Highlights: ► The crystal structure of C18En for n ≥ 20 is a monoclinic system. ► Polyethylene glycol octadecyl ether crystallizes perfectly. ► The number of repeat units has significant effect on the melting, crystallizing temperature and enthalpy. ► The thermal stable temperature increases rapidly with increasing the number of repeat unit. - Abstract: The crystal structure, phase change property and thermal stable temperature (T{sub d}) of polyethylene glycol octadecyl ether [HO(CH{sub 2}CH{sub 2}O){sub n}C{sub 18}H{sub 37}, C18En] with various numbers of repeat units (n = 2, 10, 20 and 100) as phase change materials (PCMs) were investigated using temperature variable Fourier transformed infrared spectroscopy (FTIR), wide-angle X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). C18En crystallizes perfectly at 0 °C; and the crystal structure for n ≥ 20 is a monoclinic system. The number of repeat units has great effect on the phase change properties of C18En. The thermal stable temperature increases rapidly with increasing the number of repeat units. They approach to that of PEG-2000 as the number of repeat units is more than 10. T{sub d} increases rapidly with increasing the number of repeat units. C18En are a series of promising polymeric PCMs.

  19. Thermophysical properties of ethylene glycol mixture based CNT nanofluids

    Camarano, D. M.; Mansur, F. A.; Araújo, T. L. C. F.; Salles, G. C.; Santos, A. P.

    2016-07-01

    Nanofluids are produced by dispersing nanometer-scale solid particles into base liquids such as water, ethylene glycol, etc. The thermal quadrupole method is utilized to determine the thermophysical properties of materials. By this technique, the thermal diffusivity and conductivity of different nanofluids containing the surfactants humic acid, sodium salt of humic acid and sodium carboxymethyl cellulose and multi-wall carbon nanotubes were evaluated at room temperature and at 75 oC. Values of thermal diffusivity varying in the range from 9.60x10-8 m2s-1 to 1.46x10-7 m2s-1 and thermal conductivity from 0.26 Wm-1K-1 to 41 Wm-1K-1 were obtained. As main conclusions, it was noted that nanofluids exhibit superior heat transfer characteristics than the conventional heat transfer fluid and the thermal conductivity is enhanced by 50% for the nanofluid containing 0.0275 mg/mL of sodium salt of humic acid + ethylene glycol, at the temperature of 25 oC.

  20. Effect of poly(ethylene glycol) surfactant on carbon-doped MoO3 nanocomposite materials and its photocatalytic activity

    M E Navgire; M K Lande; A B Gambhire; S B Rathod; D V Aware; S R Bhitre

    2011-06-01

    Carbon-doped MoO3 samples were prepared by impregnation method. The effect of addition of polyethylene glycol-400 (PEG-400) and carbon (0, 1, 2 and 3 wt. %) as substrates, were investigated systematically to get the desired phase of carbon-doped MoO3 material. The carbon used was prepared from the natural sources such as Acacia arabika plant wood. The resulting samples were calcined at 500°C. The effect of PEG-400 and carbon composite on the structure, particle size and morphology of MoO3 was investigated. The samples thus prepared gave better control of particle size and porosity. The prepared samples were characterized using XRD, SEM–EDS and FT–IR techniques. Photocatalytic activities of the samples were studied with degradation of methylene blue. The 3 wt.% carbon-doped MoO3 modified by PEG-400 (CMP3) sample showed enhanced photocatalytic activity in comparison with the undoped samples.

  1. Contribution to the study of some monoethers of ethylene glycol and diethylene glycol: thermal degradation, effect on sodium, application to the destruction of contaminated sodium

    A study was made of the thermal behavior in an inert atmosphere, then in air, of a family of products very much used in industry. These are methyl, ethyl and n-butyl monoethers of ethylene glycol on the one hand and diethylene glycol on the other. Additionally, these compounds were used for studying the destruction of contaminated sodium waste. The study of the destruction of contaminated sodium waste was not restricted to the alcohol-sodium reaction alone, a controllable and non-polluting process was used, permitting the recycling of the organic product used. This study includes a first chapter in which are described the results relating to the pyrolysis and combustion in air of the ethylene glycol and diethylene glycol monoethers quoted and a second chapter in which the various stages of a contaminated metal sodium waste destruction loop are described

  2. New Perspective in the Formulation and Characterization of Didodecyldimethylammonium Bromide (DMAB Stabilized Poly(Lactic-co-Glycolic Acid (PLGA Nanoparticles.

    Rebecca Gossmann

    Full Text Available Over the last few decades the establishment of nanoparticles as suitable drug carriers with the transport of drugs across biological barriers such as the gastrointestinal barrier moved into the focus of many research groups. Besides drug transport such carrier systems are well suited for the protection of drugs against enzymatic and chemical degradation. The preparation of biocompatible and biodegradable nanoparticles based on poly(lactic-co-glycolic acid (PLGA is intensively described in literature, while especially nanoparticles with cationic properties show a promising increased cellular uptake. This is due to the electrostatic interaction between the cationic surface and the negatively charged lipid membrane of the cells. Even though several studies achieved the successful preparation of nanoparticles stabilized with the cationic surfactants such as didodecyldimethylammonium bromide (DMAB, in most cases insufficient attention was paid to a precise analytical characterization of the nanoparticle system. The aim of the present work was to overcome this deficit by presenting a new perspective in the formulation and characterization of DMAB-stabilized PLGA nanoparticles. Therefore these nanoparticles were carefully examined with regard to particle diameter, zeta potential, the effect of variation in stabilizer concentration, residual DMAB content, and electrolyte stability. Without any steric stabilization, the DMAB-modified nanoparticles were sensitive to typical electrolyte concentrations of biological environments due to compression of the electrical double layer in conjunction with a decrease in zeta potential. To handle this problem, the present study proposed two modifications to enable electrolyte stability. Both polyvinyl alcohol (PVA and polyethylene glycol (PEG modified DMAB-PLGA-nanoparticles were stable during electrolyte addition. Furthermore, in contrast to unmodified DMAB-PLGA-nanoparticles and free DMAB, such modifications led to

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

    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.

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

    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. PMID:24144918

  5. Activity coefficients at infinite dilution of organic solutes in diethylene glycol and triethylene glycol from gas–liquid chromatography

    Highlights: • γ13∞ values reported for 25 organic solutes in the solvents DEG and TEG. • Measurements undertaken using the glc technique at T = (333.2, 348.2, and 363.2) K. • Measurements at elevated temperature possible by pre-saturation of carrier gas. • Comparison of DEG and TEG performance with a number of solvents. -- Abstract: The infinite dilution activity coefficients for 25 hydrocarbon solutes in diethylene glycol (DEG) and triethylene glycol (TEG) were measured using the gas–liquid chromatography technique with pre-saturation of the carrier gas. The hydrocarbon solutes included n-alkanes, alk-1-enes, alk-1-ynes, cycloalkanes, alkylbenzenes and alkanols. At the temperatures at which measurements were conducted, the solvents were volatile, and pre-saturation was considered necessary. The measurements were made at T = (333.2, 348.2 and 363.2) K. Values of the selectivity and capacity relating to DEG and TEG, for two sets of mixtures, which are usually difficult to separate by distillation or solvent extraction, were calculated from the experimental results. The two sets of mixtures were: cyclohexane and benzene; and benzene and methanol. The results obtained in this work were then compared to values for other solvents, at similar temperatures, which were obtained or calculated from literature data

  6. Preparation of the high-temperature superconductor YBa2Cu3O(7-x)

    Interrante, Leonard V.; Jiang, Zhiping; Larkin, David J.

    This paper describes the preparation of YBa2Cu3O(7-x) superconducting powders by using polyesters derived from the interaction of citric acid (CA) or ethylenediaminetetraacetic acid (EDTA) with ethylene glycol. Mixtures of the nitrate, carbonate, and/or acetate salts of the Y, Ba, and Cu are heated to obtain homogeneous solids containing the desired 1:2:3 ratios of these ions. Films of the superconductor are prepared by dropping ethylene glycol solutions of these precursors onto zirconia and alumina substrates, followed by pyrolysis to 950 C in O2. The results of studies on the structure and pyrolysis chemistry of the precursors are presented.

  7. 21 CFR 589.1001 - Propylene glycol in or on cat food.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Propylene glycol in or on cat food. 589.1001... or on cat food. The Food and Drug Administration has determined that propylene glycol in or on cat... on cat food causes the feed to be adulterated and in violation of the Federal Food, Drug,...

  8. Prehospital diagnosis of massive ethylene glycol poisoning and use of an early antidote.

    Amathieu, Roland; Merouani, Medhi; Borron, Stephen W; Lapostolle, Frédéric; Smail, Nadia; Adnet, Frédéric

    2006-08-01

    We report the case of a patient suspected of voluntary massive poisoning by ethylene glycol. Prehospital diagnosis was established by portable blood analyser and an early antidote with 4 MP treatment initiated in out-of-hospital setting. Use of portable blood analyser in prehospital care should be considered in case of suspected massive poisoning by ethylene glycol. PMID:16808995

  9. AN EVALUATION OF THE HUMAN CARCINOGENIC POTENTIAL OF ETHYLENE GLYCOL BUTYL ETHER: INTERIM FINAL POSITION PAPER

    In order to determine the merit of a petition to remove ethylene glycol ether (EGBE) from the Agency's Hazardous Air Pollutant (HAP) list, EPA has developed an interim final position paper, An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether, t...

  10. 40 CFR 721.6180 - Polyalkylene glycol polyamide ester phosphate (generic).

    2010-07-01

    ... phosphate (generic). 721.6180 Section 721.6180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.6180 Polyalkylene glycol polyamide ester phosphate (generic). (a... generically as polyalkylene glycol polyamide ester phosphate (PMN P-98-0903) is subject to reporting...

  11. Uptake of Semivolatile Secondary Organic Aerosol Formed from α-Pinene into Nonvolatile Polyethylene Glycol Probe Particles.

    Ye, Penglin; Ding, Xiang; Ye, Qing; Robinson, Ellis S; Donahue, Neil M

    2016-03-10

    Semivolatile organic compounds (SVOCs) play an essential role in secondary organic aerosol (SOA) formation, chemical aging, and mixing of organic aerosol (OA) from different sources. Polyethylene glycol (PEG400) particles are liquid, polar, and nearly nonvolatile; they provide a new vehicle to study the interaction between SVOCs with OA. With a unique fragment ion C4H9O2(+) (m/z 89), PEG400 can be easily separated from α-pinene SOA in aerosol mass spectra. By injecting separately prepared PEG probe particles into a chamber containing SOA coated on ammonium sulfate seeds, we show that a substantial pool of SVOCs exists in equilibrium with the original SOA particles. Quantitative findings are based on bulk mass spectra, size-dependent composition, and the evolution of individual particle mass spectra, which we use to separate the two particle populations. We observed a larger fraction of SVOC vapors with increased amounts of reacted α-pinene. For the same amount of reacted α-pinene, the SOA formed from α-pinene oxidized by OH radicals had a higher fraction of SOA vapors than SOA formed by α-pinene ozonolysis. Compared to the PEG400 probe particles, we observed a lower mass fraction of SVOCs in poly(ethylene glycol) dimethyl ether (MePEG500) probe particles under otherwise identical conditions; this may be due to the lower polarity of the MePEG500 or caused by esterification reactions between the PEG400 and organic acids in the SOA. PMID:26689768

  12. Polyethylene glycol-conjugated chondroitin sulfate A derivative nanoparticles for tumor-targeted delivery of anticancer drugs.

    Lee, Jae-Young; Park, Ju-Hwan; Lee, Jeong-Jun; Lee, Song Yi; Chung, Suk-Jae; Cho, Hyun-Jong; Kim, Dae-Duk

    2016-10-20

    Polyethylene glycol (PEG)-decorated chondroitin sulfate A-deoxycholic acid (CSD) nanoparticles (NPs) were fabricated for the selective delivery of doxorubicin (DOX) to ovarian cancer. CSD-PEG was synthesized via amide bond formation between the NH2 group of methoxypolyethylene glycol amine and the COOH group of CSD. CSD-PEG/DOX NPs with a 247nm mean diameter, negative zeta potential, and >90% drug encapsulation efficiency were prepared. Sustained and pH-dependent DOX release profiles from CSD-PEG NPs were observed in dissolution tests. Endocytosis of NPs by SKOV-3 cells (CD44 receptor-positive human ovarian cancer cells), based on the CSA-CD44 receptor interaction, was determined by flow cytometry and confocal laser scanning microscopy (CLSM) studies. PEGylation of NPs also resulted in reduced drug clearance (CL) in vivo and improved relative bioavailability, compared to non-PEGylated NPs, as determined by the pharmacokinetic study performed after intravenous administration in rats. Developed CSD-PEG NPs can be a promising delivery vehicle for the therapy of CD44 receptor-expressing ovarian cancers. PMID:27474544

  13. Nanoparticles of Poly(Lactide-Co-Glycolide)-d-a-Tocopheryl Polyethylene Glycol 1000 Succinate Random Copolymer for Cancer Treatment

    Ma, Yuandong; Zheng, Yi; Liu, Kexin; Tian, Ge; Tian, Yan; Xu, Lei; Yan, Fei; Huang, Laiqiang; Mei, Lin

    2010-07-01

    Cancer is the leading cause of death worldwide. Nanomaterials and nanotechnologies could provide potential solutions. In this research, a novel biodegradable poly(lactide-co-glycolide)-d-a-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) random copolymer was synthesized from lactide, glycolide and d-a-tocopheryl polyethylene glycol 1000 succinate (TPGS) by ring-opening polymerization using stannous octoate as catalyst. The obtained random copolymers were characterized by 1H NMR, FTIR, GPC and TGA. The docetaxel-loaded nanoparticles made of PLGA-TPGS copolymer were prepared by a modified solvent extraction/evaporation method. The nanoparticles were then characterized by various state-of-the-art techniques. The results revealed that the size of PLGA-TPGS nanoparticles was around 250 nm. The docetaxel-loaded PLGA-TPGS nanoparticles could achieve much faster drug release in comparison with PLGA nanoparticles. In vitro cellular uptakes of such nanoparticles were investigated by CLSM, demonstrating the fluorescence PLGA-TPGS nanoparticles could be internalized by human cervix carcinoma cells (HeLa). The results also indicated that PLGA-TPGS-based nanoparticles were biocompatible, and the docetaxel-loaded PLGA-TPGS nanoparticles had significant cytotoxicity against Hela cells. The cytotoxicity against HeLa cells for PLGA-TPGS nanoparticles was in time- and concentration-dependent manner. In conclusion, PLGA-TPGS random copolymer could be acted as a novel and promising biocompatible polymeric matrix material applicable to nanoparticle-based drug delivery system for cancer chemotherapy.

  14. Oxidative phosphorylation during glycollate metabolism in mitochondria from phototrophic Euglena gracilis.

    Collins, N; Brown, R H; Merrett, M J

    1975-09-01

    Mitochondria were isolated by gradient centrifugation on linear sucrose gradients from broken cell suspensions of phototrophically grown Euglena gracilis. An antimycin A-sensitive but rotenone-insensitive glycollate-dependent oxygen uptake was demonstrated in isolated mitochondria. The partial reactions of glycollate-cytochrome c oxidoreductase and cytochrome c oxidase were demonstrated by using Euglena cytochrome c as exogenous electron acceptor/donor. Isolated mitochondria contain glycollate dehydrogenase and glyoxylate-glutamate aminotransferase and oxidize exogenous glycine. A P:O ratio of 1.7 was obtained for glycollate oxidation, consistent with glycollate electrons entering the Euglena respiratory chain at the flavoprotein level. The significance of these results is discussed in relation to photorespiration in algae. PMID:813630

  15. PHARMACOLOGICAL SCREENING OF MUSA PARADISICA LINN AGAINST ETHYLENE GLYCOL INDUCED RENAL CALCULI

    Jha U

    2011-03-01

    Full Text Available The effect of ethanol extract of dried roots of Musa paradisica Linn against ethylene glycol induced renal calculi in albino wistar rats are studied in this research. A renal calculus was induced in rats by ingesting 0.75% ethylene glycol in drinking water for 28 days and was manifested by high urinary calcium, oxalate, and low urinary magnesium contents. Simultaneous administration of 1ml (1 in 10 Musa paradisica Linn orally for 28 days along with ethylene glycol (0.75% v/v reduced urinary calcium, oxalate and elevated urinary magnesium level. It also increased urinary volume thereby reducing the tendency for crystallization. The histopathological studies confirmed the induction as degenerated glomeruli, necrotic tubule and inflammatory cells was observed in section of kidney from animals treated with ethylene glycol. This was reduced; however after treatment with Musa paradisica Linn. These observations enable to conclude that Musa paradisica Linn is effective against ethylene glycol induced renal calculi.

  16. Detection and quantitative determination of diethylene glycol in ethyl alcohol using gamma- ray spectroscopy.

    Udagani, Chikkappa; Ramesh, Thimmasandra Narayan

    2015-08-01

    Determination of the toxic diethylene glycol contamination in ethyl alcohol demands a rapid, accurate and reliable method. Diethylene glycol (DEG) ingestion, accidental or intentional, can lead to death. Clinical and analytical methods used to detect diethylene glycol in alcohol require several hours to days due to tedious instrument handling and measurements. Enzymatic assays face difficulty due to analytic problems. As an alternative method of data analysis, we have used γ-ray spectroscopic method to estimate the diethylene glycol contamination in alcohol by monitoring the variation in the linear and mass attenuation coefficients. This method is simple, robust, portable and can provide reliable and quantitative information about the ethyl alcohol adulterated with diethylene glycol which is of broader interest to society. PMID:26243958

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

    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.

  18. Chemical peeling - Glycolic acid versus trichloroacetic acid in melasma

    Kalla G

    2001-01-01

    Full Text Available Melasma continues to be a therapeutic challenge. 100 patients of melasma not responding to conventional depigmenting agents were divided into 2 groups, one treated with 55 - 75% glycolic acid (68 patients and the other with 10-15% trichloroacetic acid (32 patients. Applications were made after every 15 days and response assessed clinically along with relapse or hyperpigmentation after 3 month follow up period. More than 75% improvement was seen in 30%, and 50-75% improvement in 24% patients. Response with TCA was more rapid as compared to GA. Chronic pigmentation responded more favourably to TCA. Relapse and hyperpigmentation was more-25% in TCA as compared to 5.9% GA. Sun exposure was the most important precipitating factor followed by pregnancy and drugs.

  19. Polyethylene glycol diffusion in ex vivo skin tissue

    Genin, V. D.; Tuchina, D. K.; Bashkatov, A. N.; Genina, E. A.; Tuchin, V. V.

    2015-11-01

    Optical clearing of the rat skin under the action of polyethylene glycol (PEG) with molecular weight 300 and 400 Dalton was studied ex vivo. The collimated transmittance was measured at the wavelength range 500-900 nm. It was found that collimated transmittance of skin samples increased, whereas weight, thickness and area of the samples decreased during PEG penetration in skin tissue. A mechanism of the optical clearing under the action of PEG is discussed. Taking into account the kinetics of volume and thickness of the skin samples, diffusion coefficient of PEGs in skin tissue has been estimated as (1.83±2.22)×10-6 cm2/s and (1.70±1.47)×10-6 cm2/s for PEG-300 and PEG-400, respectively. The presented results can be useful for enhancement of many methods of laser therapy and optical diagnostics of skin diseases and localization of subcutaneous neoplasms.

  20. Poly(lactic-co-glycolic) Acid-Chitosan Dual Loaded Nanoparticles for Antiretroviral Nanoformulations.

    Makita-Chingombe, Faithful; Kutscher, Hilliard L; DiTursi, Sara L; Morse, Gene D; Maponga, Charles C

    2016-01-01

    Poly(lactic-co-glycolic acid) (PLGA) chitosan (CS) coated nanoparticles (NPs) were loaded with two antiretrovirals (ARVs) either lamivudine (LMV) which is hydrophilic or nevirapine (NVP) which is hydrophobic or both LMV and NVP. These ARVs are of importance in resource-limited settings, where they are commonly used in human immunodeficiency virus (HIV-1) treatment due to affordability and accessibility. NPs prepared by a water-oil-water emulsion and reduced pressure solvent evaporation technique were determined to have a positive zeta potential, a capsule-like morphology, and an average hydrodynamic diameter of 240 nm. Entrapment of NVP as a single ARV had a notable increase in NP size compared to LMV alone or in combination with LMV. NPs stored at room temperature in distilled water maintained size, polydispersity (PDI), and zeta potential for one year. No changes in size, PDI, and zeta potential were observed for NPs in 10% sucrose in lyophilized or nonlyophilized states stored at 4°C and -20°C, respectively. Freezing NPs in the absence of sucrose increased NP size. Drug loading, encapsulation efficiency, and kinetic release profiles were quantified by high performance liquid chromatography (HPLC). Our novel nanoformulations have the potential to improve patient outcomes and expand drug access in resource-limited countries for the treatment of HIV-1. PMID:27190651

  1. Prevention of surgical adhesions using barriers of carboxymethyl cellulose and polyethylene glycol hydrogels synthesized by irradiation

    Biocompatible and biodegradable hydrogels based on carboxymethyl cellulose (CMC) and polyethylene glycol (PEG) were prepared for physical barriers for preventing surgical adhesions. These interpolymeric hydrogels were synthesized by a gamma irradiation crosslinking technique. The 1.5cm x 1.5cm of cecal serosa and adjacent abdominal wall were abraded with bone burr until the serosal surface was disrupted and hemorrhagic but not perforated, and the serosa of the cecum was sutured to the abdominal wall in 5 mm apart from the injured site. The denuded cecum was covered with either CMC/PEG hydrogels or solution from CMC/PEG hydrogel. Control rat serosa was not covered. Two weeks later, the rats were sacrificed and adhesion was scored on a 0-5 scale. No treatment showed the significantly higher incidence of adhesions than either CMC/PEG hydrogels or solution from CMC/PEG hydrogel. In conclusion, these studies demonstrate that CMC/PEG hydrogels have a function of prevention of intra abdominal adhesion in a rat model. (author)

  2. Anticoagulant and antithrombotic activities of low-molecular-weight propylene glycol alginate sodium sulfate (PSS).

    Xin, Meng; Ren, Li; Sun, Yang; Li, Hai-hua; Guan, Hua-Shi; He, Xiao-Xi; Li, Chun-Xia

    2016-05-23

    Propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide derivative, has been used as a heparinoid drug to prevent and treat hyperlipidemia and ischemic cardio-cerebrovascular diseases in China for nearly 30 years. To extend the applications of PSS, a series of low-molecular-weight PSSs (named FPs) were prepared by oxidative-reductive depolymerization, and the antithrombotic activities were investigated thoroughly in vitro and in vivo. The bioactivity evaluation demonstrated a positive correlation between the molecular weight and the anticoagulant and antithrombotic activities of FPs. FPs could prolong the APTT and clotting time and reduce platelet aggregation significantly. FPs could also effectively inhibit factor IIa in the presence of AT-III and HC-II. FPs decreased the wet weights and lengths of the thrombus and increased occlusion times in vivo. FP-6k, a PSS fragment with a molecular weight of 6 kDa, is an optimal antithrombotic candidate for further study and showed little chance for hemorrhagic action. PMID:26974373

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

    Díaz, A; Del Valle, L; Franco, L; Sarasua, J R; Estrany, F; Puiggalí, J

    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. PMID:25063149

  4. Synthesis and characterization of ZnO nanoparticles using polyethylene glycol (PEG)

    ZnO nanoparticles and ZnO encapsulated with polyethylene glycol (PEG) was synthesized using zinc acetate as a precursor at low temperature and characterized by different techniques. The influence of the types of solvent, synthesis parameters, and PEG encapsulation on the crystallization, the surface morphology, and the luminescent properties of ZnO nanoparticles prepared by the sol–gel process were investigated. The influence of different addition molar masses of the PEG during the synthesis on the ZnO emission peaks was systematically monitored. The crystallinity, the surface morphology, and the photoluminescence (PL) properties of ZnO depended highly on the synthesis process and PEG encapsulation. X-ray diffraction (XRD) spectra of ZnO nanoparticles show that all the peaks corresponding to the various planes of wurtzite ZnO indicate the formation of a single phase. The absorption edges of these ZnO nanoparticles are shifted by additions of the PEG polymer. The photoluminescence (PL) characterization of the ZnO nanostructures exhibited a broad emission in the visible range with maximum peak at 450 and/or 560 nm.

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

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

    2015-12-01

    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. PMID:26658212

  6. Poly(ethylene glycol) conjugated nano-graphene oxide for photodynamic therapy

    Pilger; FRANK

    2010-01-01

    A novel methoxy-poly(ethylene glycol) modified nano-graphene oxide(NGO-mPEG) was designed and synthesized as a photosensitizer(PS) carrier for photodynamic therapy of cancer.NGO with a size below 200 nm was prepared using a modified Hummers’ method.NGO was observed by AFM to exhibit a structure with single-layer graphene oxide sheets down to a few nanometers in height.Hydrophilic mPEG conjugation of NGO(NGO-mPEG) was found to enhance solubility in cell culture media.No apparent cytotoxicity of the NGO-mPEG was observed towards MCF-7 carcinoma cell line.Zinc phthalocyanine(ZnPc),a photosensitizer for photodynamic therapy,was loaded in the NGO-PEG through π-π stacking and hydrophobic interactions,with the drug loading efficiency up to 14 wt%.Hydrophobic ZnPc was internalized in MCF-7 cells,exhibiting a pronounced phototoxicity in the cells under Xe light irradiation.The results indicate a great potential of NGO-mPEG for photodynamic therapy of cancer.

  7. Electro-oxidation of ethylene glycol on nanoporous Ti-Cu amorphous alloy

    Chen Cuijie [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Zhu Shengli, E-mail: slzhu@tju.edu.cn [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Yang Xianjin [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China); Pi Lele; Cui Zhenduo [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2011-11-30

    Highlights: > Nanoporous Ti-Cu amorphous alloy exhibits apparent EG electrocatalytic ability EG electro-oxidation occurs more easily in alkaline medium than in acid medium. > In acid medium, heat treatment plays an enhancing role towards EG oxidation. > In alkaline medium, heat treatment has opposite effect below and above 0.1 V. - Abstract: This work describes ethylene glycol (EG) electro-oxidation over nanoporous structure catalyst prepared by dealloying Ti-Cu amorphous alloy. Scanning electron microscopy (SEM) was used to characterize nanoporous catalysts. Electrocatalytic performances in acid and alkaline mediums were measured by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The results showed that nanoporous Ti-Cu amorphous alloy exhibited apparent electrocatalytic ability in terms of higher oxidation current in CV and CA curves comparing to raw Ti-Cu amorphous alloy. Electro-oxidation of EG took place more easily in alkaline medium than that in acid medium. In acid medium, heat treatment improved the electrocatalytic activity of nanoporous catalyst. In alkaline medium, heat treatment played an enhancing role below 0.1 V and a depressing role above 0.1 V. Possible electro-oxidation mechanism of EG was also discussed.

  8. Experimental investigation of thermal conductivity and viscosity of ethylene glycol based ZnO nanofluids

    In this work, well dispersed ethylene glycol (EG) based nanofluids containing ZnO nanoparticles with different mass fractions between 1.75% and 10.5% were prepared by a typical two-step method. Structural properties of the dry ZnO nanoparticles were measured with X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Thermal transport properties including thermal conductivity and viscosity were experimentally measured for the nanofluids. The experimental results show that thermal conductivity increases slightly with increasing the temperature from 15 to 55 °C. It depends strongly on particle concentration and increases nonlinearly with the concentration within the range studied. The enhanced value is higher than the value predicted by the Hamilton and Crosser (H–C) model. Moreover, viscosity increases with concentration as usual for ZnO nanoparticles and decreases with temperature. For an analysis of the rheological behaviors, it shows that ZnO-EG nanofluids with mass fraction wt.% ≤ 10.5 demonstrate Newtonian behaviors

  9. Ethylene glycol assisted low-temperature synthesis of boron carbide powder from borate citrate precursors

    Rafi-ud-din

    2014-09-01

    Full Text Available B4C powders were synthesized by carbothermal reduction of ethylene glycol (EG added borate citrate precursors, and effects of EG additions (0–50 mol% based on citric acid on the morphologies and yields of synthesized B4C powders were investigated. The conditions most suitable for the preparation of precursor were optimized and optimum temperature for precursor formation was 650 °C. EG additions facilitated low-temperature synthesis of B4C at 1350 °C, which was around 100–300 °C lower temperature compared to that without EG additions. The lowering of synthesis temperature was ascribed to the enlargement of interfacial area caused by superior homogeneity and dispersibility of precursors enabling the diffusion of reacting species facile. The 20% EG addition was optimal with free residual carbon lowered to 4%. For smaller EG additions, the polyhedral and rod-like particles of synthesized product co-existed. With higher EG additions, the morphology of synthesized product was transformed into needle and blade-like structure.

  10. Poly(ethylene glycol) enhances the surface activity of a pulmonary surfactant.

    Yu, Laura M Y; Lu, James J; Chiu, Idy W Y; Leung, Kin Shun; Chan, Yawen W; Zhang, Ling; Policova, Zdenka; Hair, Michael L; Neumann, A Wilhelm

    2004-08-01

    The primary role of lung surfactant is to reduce surface tension at the air-liquid interface of alveoli during respiration. Axisymmetric drop shape analysis (ADSA) was used to study the effect of poly(ethylene glycol) (PEG) on the rate of surface film formation of a bovine lipid extract surfactant (BLES), a therapeutic lung surfactant preparation. PEG of molecular weights 3,350; 8,000; 10,000; 35,000; and 300,000 in combination with a BLES mixture of 0.5 mg/mL was studied. The adsorption rate of BLES alone at 0.5 mg/mL was much slower than that of a natural lung surfactant at the same concentration; more than 200 s are required to reach the equilibrium surface tension of 25 mJ/m(2). PEG, while not surface active itself, enhances the adsorption of BLES to an extent depending on its concentration and molecular weight. These findings suggest that depletion attraction induced by higher molecular weight PEG (in the range of 8,000 to 35,000) may be responsible for increasing the adsorption rate of BLES at low concentration. The results provide a basis for using PEG as an additive to BLES to reduce its required concentration in clinical treatment, thus reducing the cost for surfactant replacement therapy. PMID:15276633

  11. ExtraPEG: A Polyethylene Glycol-Based Method for Enrichment of Extracellular Vesicles

    Rider, Mark A.; Hurwitz, Stephanie N.; Meckes, David G.

    2016-01-01

    Initially thought to be a means for cells to eliminate waste, secreted extracellular vesicles, known as exosomes, are now understood to mediate numerous healthy and pathological processes. Though abundant in biological fluids, purifying exosomes has been challenging because their biophysical properties overlap with other secreted cell products. Easy-to-use commercial kits for harvesting exosomes are now widely used, but the relative low-purity and high-cost of the preparations restricts their utility. Here we describe a method for purifying exosomes and other extracellular vesicles by adapting methods for isolating viruses using polyethylene glycol. This technique, called ExtraPEG, enriches exosomes from large volumes of media rapidly and inexpensively using low-speed centrifugation, followed by a single small-volume ultracentrifugation purification step. Total protein and RNA harvested from vesicles is sufficient in quantity and quality for proteomics and sequencing analyses, demonstrating the utility of this method for biomarker discovery and diagnostics. Additionally, confocal microscopy studies suggest that the biological activity of vesicles is not impaired. The ExtraPEG method can be easily adapted to enrich for different vesicle populations, or as an efficient precursor to subsequent purification techniques, providing a means to harvest exosomes from many different biological fluids and for a wide variety of purposes. PMID:27068479

  12. Nanospheres and nanocapsules of amphiphilic copolymers constituted by methoxypolyethylene glycol cyanoacrylate and hexadecyl cyanoacrylate units

    J. Puiggali

    2013-01-01

    Full Text Available Nanospheres and nanocapsules of an amphiphilic copolymer having methylated polyethylene glycol and hexadecyl lateral groups were prepared by the solvent displacement method and using confined impinging jet mixers. Degradation, thermal properties and crystalline structure were investigated. Interestingly, pegylated chains hydrolyzed through ester bond cleavage, whereas the more hydrophobic hexadecyl ester groups were resistant to degradation in aqueous media. The copolymer crystallized from the melt, giving rise to spherulites with a negative birefringence and domains corresponding to crystallization of the different lateral groups. Size distribution and morphology of nanoparticles were mainly evaluated by electron microscopy. Nanocapsules were characterized by a stable membrane with a thickness close to 5 nm that allowed efficient encapsulation of a triglyceride oil. Triclosan was selected as an example of a hydrophobic drug to be loaded in both nanospheres and nanocapsules. The release behavior of these dosage forms was clearly different. Thus, the Burst effect was practically suppressed when using nanocapsules; in addition, these showed a sustained, controlled release over a greater time period. Antimicrobial activity of triclosan loaded nanospheres and nanocapsules was evaluated using Gram-negative and Gram-positive bacteria. The former were highly sensitive to the released triclosan whereas the latter strongly depended on the number of particles in the culture medium.

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

    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. - Highlights: • H2 and O2 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

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

    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.

  15. Formulation of porous poly(lactic-co-glycolic acid) microparticles by electrospray deposition method for controlled drug release

    In the present study, the electrospray deposition was successfully applied to prepare the porous poly(lactic-co-glycolic acid) (PLGA) microparticles by one-step processing. Metronidazole was selected as the model drug. The porous PLGA microparticles had high drug loading and low density, and the porous structure can be observed by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The production time has been shortened considerably compared with that of the traditional multi-emulsion method. In addition, no chemical reaction occurred between the drug and polymer in the preparation of porous microparticles, and the crystal structure of drug did not change after entrapment into the porous microparticles. The porous microparticles showed a sustained release in the simulated gastric fluid, and the release followed non-Fickian or case II transport. Furthermore, porous microparticles showed a slight cytotoxicity in vitro. The results indicated that electrospray deposition is a good technique for preparation of porous microparticles, and the low-density porous PLGA microparticles has a potential for the development of gastroretentive systems or for pulmonary drug delivery. - Highlights: • The porous PLGA microparticles were successfully prepared by the electrospray deposition method at one step. • The porous microparticles had high loading capacity and low density. • The microparticle showed a sustained release in the simulated gastric liquid. • The microparticles showed a slight cytotoxicity in vitro

  16. Formulation of porous poly(lactic-co-glycolic acid) microparticles by electrospray deposition method for controlled drug release

    Hao, Shilei; Wang, Yazhou; Wang, Bochu, E-mail: wangbc2000@126.com; Deng, Jia; Zhu, Liancai; Cao, Yang

    2014-06-01

    In the present study, the electrospray deposition was successfully applied to prepare the porous poly(lactic-co-glycolic acid) (PLGA) microparticles by one-step processing. Metronidazole was selected as the model drug. The porous PLGA microparticles had high drug loading and low density, and the porous structure can be observed by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The production time has been shortened considerably compared with that of the traditional multi-emulsion method. In addition, no chemical reaction occurred between the drug and polymer in the preparation of porous microparticles, and the crystal structure of drug did not change after entrapment into the porous microparticles. The porous microparticles showed a sustained release in the simulated gastric fluid, and the release followed non-Fickian or case II transport. Furthermore, porous microparticles showed a slight cytotoxicity in vitro. The results indicated that electrospray deposition is a good technique for preparation of porous microparticles, and the low-density porous PLGA microparticles has a potential for the development of gastroretentive systems or for pulmonary drug delivery. - Highlights: • The porous PLGA microparticles were successfully prepared by the electrospray deposition method at one step. • The porous microparticles had high loading capacity and low density. • The microparticle showed a sustained release in the simulated gastric liquid. • The microparticles showed a slight cytotoxicity in vitro.

  17. Preparation and Characterization of Ethosomes for Topical delivery of Aceclofenac

    Barupal, A. K.; Gupta, Vandana; Ramteke, Suman

    2010-01-01

    The aim of present study was to prepare and characterized ethosomes of aceclofenac which may deliver the drug to targeted site more efficiently than marketed gel preparation and also overcome the problems related with oral administration of drug. The formulations were prepared with varying the quantity of ethanol 10-50% (v/v), lecithin 1-4% (w/v), propylene glycol 5-20% (v/v) and evaluated for their vesicle size, shape and surface morphology, entrapment efficiency and in vitro drug permeation...

  18. Determination of the Impact of Glycolate on ARP and MCU Operations

    Taylor-Pashow, K. M.L.; Peters, T. B.; Fondeur, F. F.; Shehee, T. C.; Washington, A. L.

    2012-12-13

    Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal, phase separation, or coalescer performance at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similar to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The

  19. 40 CFR 721.6980 - Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols...

    2010-07-01

    ... glycol, bisphenol A-diglycidyl ether, and alky-lenepolyols polyglycidyl ethers (generic name). 721.6980... Substances § 721.6980 Dimer acids, polymer with polyalkylene glycol, bisphenol A-diglycidyl ether, and alky... reporting. (1) The chemical substance dimer acids, polymer with polyalkylene glycol, bisphenol...

  20. Thermodynamics of Triethylene Glycol and Tetraethylene Glycol Containing Systems Described by the Cubic-Plus-Association Equation of State

    Breil, Martin Peter; Kontogeorgis, Georgios

    2009-01-01

    lone pairs of oxygen. The new association scheme also takes these sites into account. The new parameters of TEG are based on the vapor pressure data, liquid density data, and liquid-liquid equilibria (LLE) data (n-heptane), and they are tested for binary systems (methane, n-octane, n-nonane, n......-decane, benzene, toluene, ethylbenzene, and water) and different types of phase equilibria (vapor-liquid equilibria (VLE) and LLE) and thermodynamic properties (heat of mixing, activity coefficients). A less extensive investigation has also been performed on tetraethylene glycol (TeEG) containing systems....... Similarly, a new seven-site association scheme for the TeEG molecule has been investigated. The new parameters of TeEG are based on vapor pressure data, liquid density data, and LLE data (n-heptane). The performance is similar to that the 4C scheme....

  1. Formation of Underbrushes on thiolated Poly (ethylene glycol) PEG monolayers by Oligoethylene glycol (OEG) terminated Alkane Thiols on Gold

    Lokanathan, Arcot R.

    2011-01-01

    Adding underbrushes of oligoethylene glycol (OEG) to monolayers of long chain PEG molecules on a surface is one of the strategies [1] in designing a suitable platform for antifouling purpose, where it is possible to have high graft density and molecular conformational freedom[4] simultaneously......, there by maximal retention of activity of covalently immobilised antifouling enzyme [2] on PEG surfaces along with resistance to protein adsorption[3]. Here we present some our studies on the addition of OEG thiol molecules over a self assembled monolayer of PEG thiol on gold. The kinetics of addition...... of OEG thiol to monolayers of PEG thiol was followed using X- ray photoelectron spectroscopy (XPS), which indicated the time point of maximum graft density and beyond this time point there was predominant desorption of OEG thiol as indicated by the C/O ratio. The initial increase in graft density was...

  2. Liquid-liquid equilibria for reservoir fluids plus monoethylene glycol and reservoir fluids plus monoethylene glycol plus water

    Frost, Michael; Kontogeorgis, Georgios; Stenby, Erling Halfdan;

    2013-01-01

    The complex phase equilibrium between reservoir fluids and associating compounds like water and glycols has become more and more important as the increasing global energy demand pushes the oil industry to use advanced methods to increase oil recovery, such as increasing the use of various chemicals...... to ensure a constant and safe production. The CPA equation of state has been successfully applied in the past to well defined systems and gas condensates, containing associating compounds. It has also been extended to reservoir fluids in presence of water and polar chemicals using modified...... correlations for critical temperature, pressure and acentric factor. This work presents new phase equilibrium data for binary MEG/reservoir fluid and ternary MEG/water/reservoir fluid systems, where two reservoir fluids from Statoil operated fields are used. The solubility data are reported over a range of...

  3. Hepatocyte-targeting gene transfer mediated by galactosylated poly(ethylene glycol- graft-polyethylenimine derivative

    Wang YQ

    2013-03-01

    Full Text Available Yuqiang Wang,1,* Jing Su,2,* Wenwei Cai,3 Ping Lu,3 Lifen Yuan,3 Tuo Jin,2 Shuyan Chen,1 Jing Sheng3 1Department of Geriatrics, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China; 3Department of Geriatrics, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China *Both authors contributed equally to this work Abstract: Biscarbamate cross-linked polyethylenimine derivative (PEI-Et has been reported as a novel nonviral vector for efficient and safe gene transfer in our previous work. However, it had no cell-specificity. To achieve specific delivery of genes to hepatocytes, galactosylated poly(ethylene glycol-graft-polyethylenimine derivative (GPE was prepared through modification of PEI-Et with poly(ethylene glycol and lactobionic acid, bearing a galactose group as a hepatocyte-targeting moiety. The composition of GPE was characterized by proton nuclear magnetic resonance. The weight-average molecular weight of GPE measured with a gel permeation chromatography instrument was 9489 Da, with a polydispersity of 1.44. GPE could effectively condense plasmid DNA (pDNA into nanoparticles. Gel retardation assay showed that GPE/pDNA complexes were completely formed at weigh ratios (w/w over 3. The particle size of GPE/pDNA complexes was 79–100 nm and zeta potential was 6–15 mV, values which were appropriate for cellular uptake. The morphology of GPE/pDNA complexes under atomic force microscopy appeared spherical and uniform in size, with diameters of 53–65 nm. GPE displayed much higher transfection efficiency than commercially available PEI 25 kDa in BRL-3A cell lines. Importantly, GPE showed good hepatocyte specificity. Also, the polymer exhibited significantly lower cytotoxicity compared to PEI 25 kDa at the

  4. Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) beads for heavy metal removal

    Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel (average diameter 150-200 μm) was prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). The copolymer hydrogel bead composition was characterized by elemental analysis and found to contain 5 EGDMA monomer units each VIM monomer unit. Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m2/g. Poly(EGDMA-VIM) beads were characterized by swelling studies and scanning electron microscopy (SEM). These poly(EGDMA-VIM) beads with a swelling ratio of 78% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Cd(II), Hg(II) and Pb(II) were investigated in aqueous media containing different amounts of these ions (10-750 mg/l) and at different pH values (3.0-7.0). Chelation rate was very fast. The maximum chelation capacities of the poly(EGDMA-VIM) beads were 69.4 mg/g for Cd(II), 114.8 mg/g for Pb(II) and 163.5 mg/g for Hg(II). The affinity order on molar basis was observed as follows: Hg(II)>Cd(II)>Pb(II). Chelation behavior of heavy metal ions could be modelled using both the Langmuir and Freundlich isotherms. pH significantly affected the chelation capacity of VIM incorporated beads. Chelation of heavy metal ions from synthetic wastewater was also studied. The chelation capacities are 45.6 mg/g for Cd(II), 74.2 mg/g for Hg(II) and 92.5 mg/g for Pb(II) at 0.5 mmol/l initial metal concentration. Regeneration of the chelating-beads was easily performed with 0.1 M HNO3. These features make poly(EGDMA-VIM) beads potential candidate adsorbent for heavy metal removal

  5. Semi-interpenetrating polymer networks composed of silk fibroin and poly(ethylene glycol) for wound dressing

    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

  6. Synthesis of polyacrylate/polyethylene glycol interpenetrating network hydrogel and its sorption of heavy-metal ions

    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.

  7. Synthesis of polyacrylate/polyethylene glycol interpenetrating network hydrogel and its sorption of heavy-metal ions

    Tang Qunwei; Sun Xiaoming; Li Qinghua; Wu Jihuai; Lin Jianming [Key Laboratory for Functional Materials of Fujian Higher Education, Institute of Material Physical Chemistry, Huaqiao University, Quanzhou 362021 (China)], E-mail: jhwu@hqu.edu.cn

    2009-01-15

    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{sup 2+}, Cr{sup 3+} and Cd{sup 2+}, the preparation conditions were optimized. In our system, the greatest amount of Ni{sup 2 +}, Cr{sup 3 +} and Cd{sup 2 +} adsorbed were 102.34, 49.38 and 33.41 mg g{sup - 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.

  8. Semi-interpenetrating polymer networks composed of silk fibroin and poly(ethylene glycol) for wound dressing

    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.

  9. Cell separation by immunoaffinity partitioning with polyethylene glycol-modified Protein A in aqueous polymer two-phase systems

    Karr, Laurel J.; Van Alstine, James M.; Snyder, Robert S.; Shafer, Steven G.; Harris, J. Milton

    1988-01-01

    Previous work has shown that polyethylene glycol (PEG)-bound antibodies can be used as affinity ligands in PEG-dextran two-phase systems to provide selective partitioning of cells to the PEG-rich phase. In the present work it is shown that immunoaffinity partitioning can be simplified by use of PEG-modified Protein A which complexes with unmodified antibody and cells and shifts their partitioning into the PEG-rich phase, thus eliminating the need to prepare a PEG-modified antibody for each cell type. In addition, the paper provides a more rigorous test of the original technique with PEG-bound antibodies by showing that it is effective at shifting the partitioning of either cell type of a mixture of two cell populations.

  10. Stability of ZnO quantum dots tuned by controlled addition of ethylene glycol during their growth

    Zimmermann, Lizandra M.; Baldissera, Paulo V.; Bechtold, Ivan H.

    2016-07-01

    ZnO quantum dots were prepared via a sol–gel route from zinc acetate and sodium hydroxide. The influence of ethylene glycol addition during the first stages of reaction (1–5 min) as a stabilizer, as well as the influence of its concentration in 2-propanol were investigated. The optimization led to particles with enough stability and homogeneity around 3.7 nm of diameter to allow for quantum confinement effect. Spectroscopic UV–vis absorption measurements allowed to explore the underlying mechanism of nucleation and growth and to have the control of it. The emission of the ZnO nanoparticles was explored under experimental perturbations with addition of small amounts of water to investigate the interplay between surface defects and the excitonic effect. The results suggest that the water interferes directly on the defects first and later on the excitonic recombination. Their morphology was determined with transmission electron microscopy.

  11. Radiation-induced graft copolymerization of poly(ethylene glycol) monomethacrylate onto deoxycholate-chitosan nanoparticles as a drug carrier

    Poly(ethylene glycol) monomethacrylate-grafted-deoxycholate chitosan nanoparticles (PEGMA-g-DCCSNPs) were successfully prepared by radiation-induced graft copolymerization. The hydrophilic poly(ethylene glycol) monomethacrylate was grafted onto deoxycholate-chitosan in an aqueous system. The radiation-absorbed dose is an important parameter on degree of grafting, shell thickness and particle size of PEGMA-g-DCCSNPs. Owing to their amphiphilic architecture, PEGMA-g-DCCSNPs self-assembled into spherical core–shell nanoparticles in aqueous media. The particle size of PEGMA-g-DCCSNPs measured by TEM varied in the range of 70–130 nm depending on the degree of grafting as well as the irradiation dose. Berberine (BBR) as a model drug was encapsulated into the PEGMA-g-DCCSNPs. Drug release study revealed that the BBR drug was slowly released from PEGMA-g-DCCSNPs at a mostly constant rate of 10–20% in PBS buffer (pH 7.4) at 37 °C over a period of 23 days. - Highlights: • PEGMA was successfully grafted onto DCCS via radiation-induced graft copolymerization (RIGC). • γ-Ray dose control PEGMA shell thickness (10–30 nm) and particle size (70–130 nm). • The dose of 2 kGy is sufficient for preparing core–shell PEGMA-g-DCCSNPs (80 nm). • PEGMA-g-DCCSNPs show capacity in drug encapsulation and control release. • RIGC serves as a simple, potential and green for synthesizing drug carrier

  12. EXPOSURE TO ETHYLENE GLYCOL MONOBUTYL ETHER AND RELATED WORKERS HABITS IN AN INK FACTORY

    W. C. Lin, H. Y. Chang, F. H. Chang

    2008-01-01

    Full Text Available Forty six workers from an ink factory were included in this study, in which, passive badge sampler and questionnaire interview were used to assess the concentrations of airborne exposure to ethylene glycol monobutyl ether during work shifts and to understand the subjects' working habits. The geometric mean value (95% confidence interval of the airborne ethylene glycol monobutyl ether concentrations was 0.12(0.08-0.19ppm, with a range of <0.02-1.82ppm. The exposure group was exposed to statistically significantly higher ethylene glycol monobutyl ether concentrations than the control group (geometric mean value: 0.14vs. 0.03ppm; P=0.017. Some chromatograms showed that subjects were co-exposed to m-xylene, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether acetate. According to the completed questionnaires, subjects might also be exposed to 1,2,4,5-tetramethylbenzene, propylene glycol ethers, ethanol, 1,2,4-trimethylbenzene, methanol and diisononyl phthalate. This study also suggests that, the Taiwan occupational time-weighted average level of ethylene glycol monobutyl ether be reconsidered with a view to being lowered.

  13. Evaluation of ElectrochemicalTreatment in Degradation of Wastewater Contaminated by Propylene Glycol

    M.R Talaiekhozani

    2010-02-01

    Full Text Available "n "nBackgrounds and Objectives:Propylene glycol is applied in many industries as raw material and can be released to the environment through wastewater of such industries. The biological treatment of solutions containing high concentration of propylene glycol is difficult and some problems can be observed during this process. The main objective of this study was the investigation of electrochemical degradation of propylene glycol and the parameters influencing on improving removal efficiency."nMaterials and Methods: In this study the degradation of propylene glycol was made by passing an electrical current though the synthetic wastewater containing propylene glycol. In order to investigate this process several types of electrode with applied voltage ranging between 5 to 50 V was used. Due to the effect of NaCl concentration on removal efficiency which was mentioned in the literature, the experiment was performed for different NaCl concentrations."nResults: In optimum condition, the maximum removal efficiency of propylene glycol (based onCOD was obtained equal to 90%. The results showed that rising applied voltage, NaCl concentrationand retention time increase the removal efficiency. The optimum retention time was obtained equalto 50 min. The maximum removal was obtained when aluminum electrode was used. It can beattributed to the production of coagulant material such as Al+3 during this process."nConclusion: The results revealed that this process can be useful for treating the industrial wastewatercontaining propylene glycol.

  14. The influence of water mixtures on the dermal absorption of glycol ethers

    Glycol ethers are solvents widely used alone and as mixtures in industrial and household products. Some glycol ethers have been shown to have a range of toxic effects in humans following absorption and metabolism to their aldehyde and acid metabolites. This study assessed the influence of water mixtures on the dermal absorption of butoxyethanol and ethoxyethanol in vitro through human skin. Butoxyethanol penetrated human skin up to sixfold more rapidly from aqueous solution (50%, 450 mg/ml) than from the neat solvent. Similarly penetration of ethoxyethanol was increased threefold in the presence of water (50%, 697 mg/ml). There was a corresponding increase in apparent permeability coefficient as the glycol ether concentration in water decreased. The maximum penetration rate of water also increased in the presence of both glycol ethers. Absorption through a synthetic membrane obeyed Fick's Law and absorption through rat skin showed a similar profile to human skin but with a lesser effect. The mechanisms for this phenomenon involves disruption of the stratum corneum lipid bilayer by desiccation by neat glycol ether micelles, hydration with water mixtures and the physicochemical properties of the glycol ether-water mixtures. Full elucidation of the profile of absorption of glycol ethers from mixtures is required for risk assessment of dermal exposure. This work supports the view that risk assessments for dermal contact scenarios should ideally be based on absorption data obtained for the relevant formulation or mixture and exposure scenario and that absorption derived from permeability coefficients may be inappropriate for water-miscible solvents

  15. Vapour pressures and densities of the mixed-solvent desiccants (glycols + water + salts)

    The vapour pressures and densities of the mixed-solvent desiccants have been studied for temperatures ranging from (303.15 to 343.15) K. The mixed-solvent desiccants investigated were aqueous-organic systems with salt. The studied organic solvents were diethylene glycol, tetraethylene glycol, and dipropylene glycol. The chosen salts were lithium chloride and lithium bromide. Six ternaries (glycol/water/salt) were selected for this study. For each ternary system, four systems of which (4-25) mass% salt mixed with various glycols (50-80) mass% were investigated. Incorporated with the pseudo-solvent approach, a vapour pressure model based on the mean spherical approximation for aqueous electrolyte solutions was used to represent the measured vapour pressure of glycol/water/salt systems. A simplified density equation was applied to model the measured density of glycol/water/salt systems. Satisfactory results were obtained for vapour pressure and density calculations. The vapour pressures of the aqueous-organic systems with salt yield smaller values of vapour pressures compared to the conventionally used liquid desiccants. The properties obtained and presented in this study are, in general, of sufficient accuracy for most engineering-design calculations, such as the design of dehumidifier process using mixed-solvent desiccants as absorbents.

  16. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve A mechanical analysis*

    Tao Yu; Changfu Zhao; Peng Li; Guangyao Liu; Min Luo

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study col ected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, fol owing which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transplanted. Scanning electron microscopy revealed that the axon and myelin sheath were torn, and the vessels of basilar membrane were obstructed in the poly(lactic-co-glycolic acid) con-duit-repaired sciatic nerve fol owing tensile testing. There were no significant differences in tensile tests with autogenous nerve graft-repaired sciatic nerve. Fol owing poly(lactic-co-glycolic acid) conduit transplantation for sciatic nerve repair, tensile test results suggest that maximum tensile load, maximum stress, elastic limit load and elastic limit stress increased compared with autogen-ous nerve grafts, but elastic limit strain and maximum strain decreased. Moreover, the tendencies of stress-strain curves of sciatic nerves were similar after transplantation of poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts. Results showed that after transplantation in vitro for sciatic nerve injury, poly(lactic-co-glycolic acid) conduits exhibited good intensity, elasticity and plasticity, indicating that poly(lactic-co-glycolic acid) conduits are suitable for sciatic nerve injury repair.

  17. Thermal conductivity of dry anatase and rutile nano-powders and ethylene and propylene glycol-based TiO2 nanofluids

    Highlights: • Stable ethylene and propylene glycol based TiO2 nanofluids were prepared. • A device for measuring the thermal conductivity of dry nanopowders is presented. • Nanofluid thermal conductivity enhancements reach values up to 15.4%. • Nanofluids involving anatase nanocrystalline present slightly superior enhancements. • A parallel model using nanopowder measures gives good conductivity predictions for TiO2-nanofluid. - Abstract: Thermal conductivity behaviour was studied for two TiO2 nano-powders with different nanocrystalline structures, viz. anatase and rutile, as well as nanofluids formulated as dispersions of these two oxides up to volume concentrations of 8.5% in two different glycols, viz. ethylene and propylene glycol. Because it is known that titanium dioxide can exhibit three different crystalline structures, the dry nano-powders were analysed using X-ray Diffraction to determine the nanocrystalline structure of the powders. Two different techniques were employed in the thermal conductivity study of the materials. Dry nano-powders, with and without compaction, were analysed at room temperature by using a device based on the guarded heat flow meter method. Nanofluids and base fluids were studied with a transient hot wire technique over the temperature range from (283.15 to 343.15) K. The base fluid propylene glycol was measured by using both techniques in order to verify the good agreement between both sets of results. The experimental measurements presented in this work were compared with other literature data for TiO2 nanofluids in order to understand the thermal conductivity enhancement as a function of nanoparticle concentration. Different theoretical or semi-theoretical approaches such as Maxwell, Peñas et al., Yu-Choi were evaluated comparing with our experimental values. A parallel model was used to predict thermal conductivities employing experimental values for dry nanopowder

  18. Effects of ethanol on the in situ synthesized Cu/SiC》2 catalyst: Texture, structure, and the catalytic performance in hydrogenation dimethyl oxalate to ethylene glycol

    Shu Rong Wang; Ling Jun Zhu; Ying Ying Zhu; Xiao Lan Ge; Xin Bao Li

    2011-01-01

    The Cu/SiO2 catalysts were in situ synthesized by the hydrolysis of tetraethyl orthosilicate (TEOS) in one phase solution using ethanol as co-solvent or TEOS/H2O two phases solution, followed by the precipitation of copper on SiO2 by ammonia evaporation. In the hydrogenation of dimethyl oxalate, the catalyst prepared by one phase hydrolysis exhibited higher activity and ethylene glycol (EG) selectivity at lower temperature than that of two phases due to its larger BET surface area and multimodal pore distribution. At 488-503 K, the catalyst prepared in one phase solution with water/ethanol (W/E) volume ratio of 3:1 exhibited 90-95% EG selectivity, while catalyst prepared by two phase hydrolysis reached 90% EG selectivity only at 498-503 K.

  19. Effect of Copper Nanoparticles Dispersion on Catalytic Performance of Cu/SiO2 Catalyst for Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

    Cu/SiO2 catalysts, for the synthesis of ethylene glycol (EG) from hydrogenation of dimethyl oxalate (DMO), were prepared by ammonia-evaporation and sol-gel methods, respectively. The structure, size of copper nanoparticles, copper dispersion, and the surface chemical states were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) and N2 adsorption. It is found the structures and catalytic performances of the catalysts were highly affected by the preparation method. The catalyst prepared by sol-gel method had smaller average size of copper nanoparticles (about 3-4 nm), better copper dispersion, higher Cu+/C0 ratio and larger BET surface area, and higher DMO conversion and EG selectivity under the optimized reaction conditions.

  20. Effect of Copper Nanoparticles Dispersion on Catalytic Performance of Cu/SiO2 Catalyst for Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

    Yajing Zhang

    2013-01-01

    Full Text Available Cu/SiO2 catalysts, for the synthesis of ethylene glycol (EG from hydrogenation of dimethyl oxalate (DMO, were prepared by ammonia-evaporation and sol-gel methods, respectively. The structure, size of copper nanoparticles, copper dispersion, and the surface chemical states were investigated by X-ray diffraction (XRD, transmission electron microscopy (TEM, temperature-programmed reduction (TPR, and X-ray photoelectron spectroscopy (XPS and N2 adsorption. It is found the structures and catalytic performances of the catalysts were highly affected by the preparation method. The catalyst prepared by sol-gel method had smaller average size of copper nanoparticles (about 3-4 nm, better copper dispersion, higher Cu+/C0 ratio and larger BET surface area, and higher DMO conversion and EG selectivity under the optimized reaction conditions.

  1. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  2. Update: An efficient synthesis of poly(ethylene glycol)-supported iron(II) porphyrin using a click reaction and its application for the catalytic olefination of aldehydes

    Chinnusamy, Tamilselvi R.

    2012-05-09

    The facile synthesis of polyethylene glycol (PEG)-immobilized iron(II) porphyrin using a copper-catalyzed azide-alkyne [3+2] cycloaddition "click" reaction is reported. The prepared complex 5 (PEG-C 51H 39FeN 7O) was found to be an efficient catalyst for the selective olefination of aldehydes with ethyl diazoacetate in the presence of triphenylphosphine, and afforded excellent olefin yields with high (E) selectivities. The PEG-supported catalyst 5 was readily recovered by precipitation and filtration, and was recycled through ten runs without significant activity loss. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. An HPLC Method for Microanalysis and Pharmacokinetics of Marine Sulfated Polysaccharide PSS-Loaded Poly Lactic-co-Glycolic Acid (PLGA) Nanoparticles in Rat Plasma

    Hua-Shi Guan; Guang-Li Yu; Xiao-Xi He; Hong-Bing Liu; Hai-Hua Li; Yi-Ting Xue; Chun-Xia Li; Peng-Li Li

    2013-01-01

    This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS) in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with d-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of...

  4. A Case of Chronic Ethylene Glycol Intoxication Presenting without Classic Metabolic Derangements

    Stephanie M. Toth-Manikowski

    2014-01-01

    Full Text Available Acute ethylene glycol ingestion classically presents with high anion gap acidosis, elevated osmolar gap, altered mental status, and acute renal failure. However, chronic ingestion of ethylene glycol is a challenging diagnosis that can present as acute kidney injury with subtle physical findings and without the classic metabolic derangements. We present a case of chronic ethylene glycol ingestion in a patient who presented with acute kidney injury and repeated denials of an exposure history. Kidney biopsy was critical to the elucidation of the cause of his worsening renal function.

  5. Allergic contact dermatitis to propyl gallate and pentylene glycol in an emollient cream.

    Foti, Caterina; Bonamonte, Domenico; Cassano, Nicoletta; Conserva, Anna; Vena, Gino A

    2010-05-01

    A 62-year-old man, with a 20-year history of seborrhoeic dermatitis, presented with a worsening of his dermatitis. He had previously been demonstrated to be allergic to various topical corticosteroids, so he had been using an emollient cream (Sebclair), containing piroctone olamine and various anti-inflammatory substances, for 6 months, with good effect. Patch testing to the cream and its ingredients revealed positive reactions to both propyl gallate and pentylene glycol. A positive reaction to propylene glycol was also detected, whereas patch testing to butylene glycol was negative. Complete remission followed avoidance of the offending substances. PMID:20546226

  6. Preparation and characterization of crosslinked chitosan-based nanofibers

    Ying Shan Zhou; Dong Zhi Yang; Jun Nie

    2007-01-01

    Crosslinked chitosan-based nanofibers were successfully prepared via electrospinning technique with heat mediated chemical crosslinking followed. The structure, morphology and mechanical property of nanofibers were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), Instron machine, respectively. The results showed that, nanofibers exhibited a smooth surface and regular morphology, and tensile strength of nanofibers improved with increasing of triethylene glycol dimethacrylate (TEGDMA) content.

  7. PtRu/C electrocatalysts prepared using electron beam irradiation

    Dionísio Furtunato da Silva; Almir Oliveira Neto; Eddy Segura Pino; Michele Brandalise; Marcelo Linardi; Estevam Vitorio Spinacé

    2007-01-01

    PtRu/C electrocatalysts (carbon-supported PtRu nanoparticles) were prepared submitting water/ethylene glycol mixtures containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The electrocatalysts were characterized by energy dispersive X ray analysis (EDX), X ray diffraction (XRD) and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts showed superior performance for methanol electro-oxi...

  8. Preparation of Polyvinylidene Fluoride (PVDF) Hollow Fiber Hemodialysis Membranes

    Qinglei Zhang; Xiaolong Lu; Lihua Zhao

    2014-01-01

    In this study, the polyvinylidene fluoride (PVDF) hollow fiber hemodialysis membranes were prepared by non-solvent induced phase separation (NIPS). The influences of PVDF membrane thickness and polyethylene glycol (PEG) content on membrane morphologies, pore size, mechanical and permeable performance were investigated. It was found that membrane thickness and PEG content affected both the structure and performance of hollow fiber membranes. The tensile strength and rejection of bovine serum a...

  9. Facile spectrophotometric assay of molar equivalents of N-hydroxysuccinimide esters of monomethoxyl poly-(ethylene glycol derivatives

    Gao Ang

    2012-11-01

    Full Text Available Abstract Background A new method is developed to quantify molar equivalents of N-hydroxysuccinimide (NHS esters of derivatives of monomethoxyl poly-(ethylene glycol (mPEG in their preparations with NHS acetate ester as the reference. Results NHS ester of succinic monoester or carbonate of mPEG of 5,000 Da was synthesized and reacted with excessive ethanolamine in dimethylformamide at 25°C for 15 min. Residual ethanolamine was subsequently quantified by absorbance at 420 nm after reaction with 2,4,6-trinitrobenzenesulfonic acid (TNBS at pH 9.2 for 15 min at 55°C followed by cooling with tap water. Reaction products of ethanolamine and NHS esters of mPEG caused no interference with TNBS assay of residual ethanolamine. Reaction between ethanolamine and NHS acetate ester follows 1:1 stoichiometry. By the new method, molar equivalents of NHS esters of carbonate and succinic monoester of mPEG in their preparations were about 90% and 60% of their theoretical values, respectively. During storage at 37°C in humid air, the new method detected spontaneous hydrolyses of the two NHS esters of mPEG more sensitively than the classical spectrophotometric method based on absorbance at 260 nm of NHS released by reaction with ammonia in aqueous solution. Conclusion The new method is favorable to quantify molar equivalents of NHS esters of mPEG derivatives and thus control quality of their preparations.

  10. Improved cellular infiltration into nanofibrous electrospun cross-linked gelatin scaffolds templated with micrometer-sized polyethylene glycol fibers

    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 μm, as estimated with mercury intrusion porosimetry. Non-templated gelatin-based nanofibrous matrices had an average pore size of 1 μm. 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 μm, 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 μm 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.

  11. Improved cellular infiltration into nanofibrous electrospun cross-linked gelatin scaffolds templated with micrometer-sized polyethylene glycol fibers

    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.

  12. DETERMINATION OF THE IMPACT OF GLYCOLATE ON ARP AND MCU OPERATIONS

    Taylor-Pashow, K.; Peters, T.; Shehee, T.

    2012-06-04

    Savannah River Remediation (SRR) is evaluating an alternate flowsheet for the Defense Waste Processing Facility (DWPF) using glycolic acid as a reductant. An important aspect of the development of the glycolic acid flowsheet is determining if glycolate has any detrimental downstream impacts. Testing was performed to determine if there is any impact to the strontium and actinide sorption by monosodium titanate (MST) and modified monosodium titanate (mMST) or if there is an impact to the cesium removal at the Modular Caustic-Side Solvent Extraction Processing Unit (MCU). Sorption testing was performed using both MST and modified MST (mMST) in the presence of 5,000 and 10,000 ppm (mass basis) glycolate. 10,000 ppm is the estimated bounding concentration expected in the DWPF recycle stream based on DWPF melter flammable gas model results. The presence of glycolate was found to slow the removal of Sr and Pu by MST, while increasing the removal rate of Np. Results indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. There was no measurable effect on U removal at either glycolate concentration. The slower removal rates for Sr and Pu at 5,000 and 10,000 ppm glycolate could result in lower DF values for these sorbates in ARP based on the current (12 hours) and proposed (8 hours) contact times. For the highest glycolate concentration used in this study, the percentage of Sr removed at 6 hours of contact decreased by 1% and the percentage of Pu removed decreased by nearly 7%. The impact may prove insignificant if the concentration of glycolate that is returned to the tank farm is well below the concentrations tested in this study. The presence of glycolate also decreased the removal rates for all three sorbates (Sr, Pu, and Np) by mMST. Similarly to MST, the results for mMST indicate that the impact is a kinetic effect, and the overall capacity of the material is not affected. The presence of glycolate did not change the lack

  13. Photochemical Synthesis and Versatile Functionalization Method of a Robust Porous Poly(ethylene glycol methacrylate-co-allyl methacrylate) Monolith Dedicated to Radiochemical Separation in a Centrifugal Microfluidic Platform

    Marion Losno; Ivan Ferrante; René Brennetot; Jérôme Varlet; Cécile Blanc; Bernard Grenut; Etienne Amblard; Stéphanie Descroix; Clarisse Mariet

    2016-01-01

    The use of a centrifugal microfluidic platform is an alternative to classical chromatographic procedures for radiochemistry. An ion-exchange support with respect to the in situ light-addressable process of elaboration is specifically designed to be incorporated as a radiochemical sample preparation module in centrifugal microsystem devices. This paper presents a systematic study of the synthesis of the polymeric porous monolith poly(ethylene glycol methacrylate-co-allyl methacrylate) used as ...

  14. Solution preparation

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results

  15. Preparation of zinc sulfide nanocrystallites from single-molecule precursors

    Palve, Anil M.; Garje, Shivram S.

    2011-07-01

    Zinc sulfide nanocrystallites were prepared using Zinc(II) thiosemicarbazone complexes of the types Zn(L) 2 and ZnCl 2(LH) 2 (where, LH=thiosemicarbazones of cinnamaldehyde, 4-chlorobenzaldehyde, indol-3-carboxaldehyde and thiophene-2-carboxaldehyde) as single source precursors by solvothermal decomposition in ethylene glycol and ethylene diamine in few cases. The materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction, energy dispersive X-ray analysis and UV-vis and IR spectroscopy. Solvothermal decomposition in ethylene glycol resulted in the formation of hexagonal ZnS (JCPDS: 36-1450) as evident from the XRD patterns. However, XRD shows formation of hybrid material, ZnS 0.5EN in case of solvothermal decomposition in ethylenediamine. Infrared spectra authenticate the capping of ethylene glycol and ethylenediamine on ZnS and ZnS 0.5EN, respectively. TEM images showed formation of spherical nanoparticles for the materials obtained from ethylene glycol, whereas plate-like morphology is observed in case of materials obtained from ethylene diamine. The blue shift of absorption bands compared to bands of bulk materials in the UV-vis spectra supports the formation of smaller particles.

  16. Immediate-type hypersensitivity to polyethylene glycols: a review.

    Wenande, E; Garvey, L H

    2016-07-01

    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 and structurally related derivatives is likely underestimated. Most healthcare professionals have no knowledge of PEG and thus do not suspect PEG's as culprit agents in hypersensitivity reactions. In consequence, patients are at risk of misdiagnosis and commonly present with a history of repeated, severe reactions 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 for allergists and other healthcare professionals by describing the clinical picture of 37 reported cases of PEG hypersensitivity since 1977, summarizing instances where PEG hypersensitivity should be considered and proposing an algorithm for diagnostic management. PMID:27196817

  17. Biocompatible and target specific hydrophobically modified glycol chitosan nanoparticles.

    Yin, Wei; Li, Weiyi; Rubenstein, David A; Meng, Yizhi

    2016-01-01

    Cardiovascular disease is the leading cause of death in the United States. Atherosclerosis is a major cause for cardiovascular diseases. Drugs that treat atherosclerosis usually act nonspecifically. To enhance drug delivery specificity, the authors developed a hydrophobically modified glycol chitosan (HGC) nanoparticle that can specifically target activated endothelial cells. The biocompatibility of these nanoparticles toward red blood cells and platelets was evaluated through hemolysis, platelet activation, platelet thrombogenicity, and platelet aggregation assays. The biocompatibility of these nanoparticles toward vascular endothelial cells was evaluated by their effects on endothelial cell growth, metabolic activity, and activation. The results demonstrated that HGC nanoparticles did not cause hemolysis, or affect platelet activation, thrombogenicity, and aggregation capability in vitro. The nanoparticles did not impair vascular endothelial cell growth or metabolic activities in vitro, and did not cause cell activation either. When conjugated with intercellular adhesion molecular 1 antibodies, HGC nanoparticles showed a significantly increased targeting specificity toward activated endothelial cells. These results suggested that HGC nanoparticles are likely compatible toward red blood cells, platelets, and endothelial cells, and they can be potentially used to identify activated endothelial cells at atherosclerotic lesion areas within the vasculature, and deliver therapeutic drugs. PMID:27126597

  18. Solubility of sulphur dioxide in mixed polyethylene glycol dimethyl ethers

    The purpose of this study is to discuss the harmful effects of increased sulphur dioxide in the atmosphere, to select an appropriate solvent for the regenerable removal of sulphur dioxide from tail gas streams, to collect solubility data over a wide range of temperatures and pressures, and to correlate the results for use in the design of these facilities. Excess enthalpy and the partial molar enthalpies of solution/absorption and mixing were also calculated from the solubility data and were examined in the context of solubility enhancement and solvent-solute interactions. The effect of water on the solubility of sulphur dioxide was also investigated with a 6.04 mass per cent water solution. Overall results showed that the best solvents for sulphur dioxide have been those with a good donor ability. DMEPEG, a mixture of dimethyl ether polyethylene glycol has been recommended because it satisfies the criteria for a good sulphur dioxide removal solvent and because of the many other advantageous properties it has for regenerable sulphur dioxide removal. It was concluded that the solubility data, the correlated results and the calculated enthalpies of solution and mixing can be used in evaluating and designing a potential sulphur dioxide removal facility with DMEPEG. 77 refs., 10 tabs., 9 figs., 1 appendix

  19. Air dehumidification by triethylene glycol desiccant in a packed column

    The performance of an air dehumidifier using triethylene glycol (TEG) as desiccant under hot and humid conditions was investigated. The performance of the dehumidifier was evaluated and expressed in terms of the moisture removal rate and the dehumidifier effectiveness. A packed bed column (dehumidifier) was employed, with low packing density (77 m2/m3), to provide direct contact between the air and the TEG. Two different structured packings were used, wood and aluminum. The experiments covered a wide range of parameter space that included the air and TEG flow rates, air and TEG inlet temperatures, inlet air humidity and inlet TEG concentration. The liquid flow rate investigated is much less than that covered in previous studies (2 s). The trend of the dehumidifier performance was similar to that reported in the literature using high density and random packing. The results were compared to the Chung and Luo correlation, which over predicted the effectiveness. The Martin and Goswami correlation failed to predict the effectiveness under the conditions of this study. In the present study, it was found that the moisture removal rate increased with increasing inlet TEG concentration, TEG flow rate and air flow rate. This was seen for both the wood and the aluminum packings. In addition, the moisture removal rate is increased with increasing the inlet air temperature for the aluminum packing only. The effectiveness of the column was increased by increasing the TEG flow rate and inlet TEG temperature for the two packings

  20. Air dehumidification by triethylene glycol desiccant in a packed column

    Zurigat, Y.H.; Abu-Arabi, M.K.; Abdul-Wahab, S.A. E-mail: sabah1@squ.edu.om

    2004-01-01

    The performance of an air dehumidifier using triethylene glycol (TEG) as desiccant under hot and humid conditions was investigated. The performance of the dehumidifier was evaluated and expressed in terms of the moisture removal rate and the dehumidifier effectiveness. A packed bed column (dehumidifier) was employed, with low packing density (77 m{sup 2}/m{sup 3}), to provide direct contact between the air and the TEG. Two different structured packings were used, wood and aluminum. The experiments covered a wide range of parameter space that included the air and TEG flow rates, air and TEG inlet temperatures, inlet air humidity and inlet TEG concentration. The liquid flow rate investigated is much less than that covered in previous studies (<1 kg/m{sup 2} s). The trend of the dehumidifier performance was similar to that reported in the literature using high density and random packing. The results were compared to the Chung and Luo correlation, which over predicted the effectiveness. The Martin and Goswami correlation failed to predict the effectiveness under the conditions of this study. In the present study, it was found that the moisture removal rate increased with increasing inlet TEG concentration, TEG flow rate and air flow rate. This was seen for both the wood and the aluminum packings. In addition, the moisture removal rate is increased with increasing the inlet air temperature for the aluminum packing only. The effectiveness of the column was increased by increasing the TEG flow rate and inlet TEG temperature for the two packings.

  1. On the Structure of Holographic Polymer-dispersed Polyethylene Glycol

    Birnkrant,M.; McWilliams, H.; Li, C.; Natarajan, L.; Tondiglia, V.; Sutherland, R.; Lloyd, P.; Bunning, T.

    2006-01-01

    Holographic polymerization (H-P) has been used to fabricate polymer-dispersed liquid crystals and pattern inert nanoparticles. In this article, one-dimensional grating structures of Norland resin and polyethylene glycol (PEG) were achieved using the H-P technique. Both reflection and transmission grating structures were fabricated. The optical properties of the reflection grating structures (also known as Bragg reflectors, BRs) are thermosensitive, which is attributed to the formation and crystallization of PEG crystals. The thermal switching temperature of the BR can be tuned by using different molecular weight PEG samples. The hierarchical structure and morphology of the BR were studied using synchrotron X-ray, polarized light microscopy and transmission electron microscopy. PEG crystals were found to be confined in {approx}60 nm thick layers in the BR. Upon crystallization, the PEG lamellae were parallel to the BR surfaces and PEG chains were parallel to the BR normal, resembling the confined crystallization behavior of polyethylene oxide (PEO) in PEO-block-polystyrene (PEO-b-PS) block copolymers. This observation suggests that the tethering effect in the block copolymer systems does not play a major role in PEG chain orientation in the confined nanoenvironment.

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

    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.

  3. Capture and utilization of carbon dioxide with polyethylene glycol

    Yang, Zhen-Zhen; He, Liang-Nian; Song, Qing-Wen [Nankai Univ., Tianjin (China). State Key Lab. of Elemento-Organic Chemistry

    2012-11-01

    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-functionalized catalysts for efficient transformation of CO2 and PEG-functionalized absorbents for efficient CO2 capture. Furthermore, they describe carbon capture and utilization strategy as an alternative approach to address the energy penalty problem in carbon capture and storage. Interestingly, the authors also discuss PEG radical chemistry in dense CO2 as rather creative and unusual use of PEG, presumably serves as a reaction medium and a radical initiator for radical chemistry.

  4. Prediction of scale potential in ethylene glycol containing solutions

    Sandengen, Kristian; Oestvold, Terje

    2006-03-15

    This work presents a method for scale prediction in MEG (Mono Ethylene Glycol / 1,2-ethane-diol) containing solutions. It is based on an existing PVT scale model using a Pitzer ion interaction model for the aqueous phase. The model is well suited for scale prediction in saline solutions, where the PVT part is necessary for calculating CO{sub 2} phase equilibria being critical for carbonate scale. MEG influences the equilibria contained in the model, and its effect has been added empirically. Thus the accuracy of the model is limited by the amount of available experimental data. The model is applicable in the range 0-99wt% MEG and includes a wide variety of salts. In addition to the aspects of scale modelling in MEG+water solutions, this work presents new experimental data on CaSO4 solubility (0-95wt% MEG and 22-80 deg.C). CaSO4 solubility is greatly reduced by MEG to an extent that ''Salting-out'' is possible. (author) (tk)

  5. Optical clearing of skin tissue ex vivo with polyethylene glycol

    Tuchina, D. K.; Genin, V. D.; Bashkatov, A. N.; Genina, E. A.; Tuchin, V. V.

    2016-01-01

    Alterations of the optical and structural (weight, thickness, and square) parameters of skin caused by polyethylene glycol (PEG) with molecular weights of 300 and 400 Da were studied experimentally. The objects of the study were ex vivo skin samples of albino laboratory rats. Collimated transmittance of the skin was measured in the wavelength range 500-900 nm. As a result of exposure to the agents, an increase in the collimated transmittance and a decrease in weight, thickness, and square of skin samples were observed. Analysis of the kinetics of parameters alterations allowed us to measure the diffusion coefficient of the agents in the skin as (1.83 ± 2.22) × 10-6 and (1.70 ± 1.47) × 10-6 cm2/s for PEG-300 and PEG-400, respectively, and the rate of alterations of the structural parameters. The results obtained in this study can be used for the improvement of existing and development of new methods of noninvasive diagnostics and therapy of subcutaneous diseases.

  6. Preparation and evaluation of monolithic molecularly imprinted stationary phase for S-naproxen

    De-Miao Chen; Qiang Fu; Wei Du; Si-Juan Sun; Ping Huang; Chun Chang

    2011-01-01

    An S-naproxen(S-NAP)molecularly imprinted monolithic stationary phase(MIMSP)with specific recognition for S-NAP and naproxen(NAP)was prepared by in situ technique,utilizing 4-vinylpridine(4-VP)as a function monomer,ethylene glycol dimethacrylate(EDMA)as a

  7. Preparation and Haemocompatibility of Regular Array Microporous PLGA Films on Stainless Steel Surface

    2005-01-01

    Regular array microporous films from poly ( L-lactic-co-glycolic acid) ( PLGA ) were prepared on stainless steel substrates utilizing the condensation of water droplets on polymer solutions. The size of the pores and regularity can be controlled by atmospheric humidity and concentration of polymer solution. The microporons films have strong hydrophobicity and good haemocompatibility.

  8. Rate-controlled rectal drug delivery in man with a hydrogel preparation

    Leede, de L.G.J.; Boer, de A.G.; Pörtzgen, E.; Feijen, J.; Breimer, D.D.

    1986-01-01

    Cylindrical hydrogels of hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent were prepared by radical polymerization at 70°C. After washing they were soaked in an aqueous drug solution of antipyrine or theophylline. The in vitro drug release experiments

  9. Antimicrobial effect and enzymatic activity of extract of Zingiber officinale Roscoe and stability in topical preparations

    Gisele Mara Silva Gonçalves; Gustavo Henrique da Silva; Pedro Paulo Barros; Silvana Mariana Srebernich; Fernanda Rocha Tonon; Daniella Souza Fiore

    2014-01-01

    The rhizomes of common ginger (Zingiber officinale Roscoe) contain substances with antimicrobial activity and proteolytic enzymes and thus may have various pharmaceutical applications. The aim of the present study was to prepare Zingiber officinale Roscoe rhizome extracts for pharmaceutical use, preserving the proteolytic enzyme activity and testing the antimicrobial activity, in order to develop topical formulations. Two extracts were obtained - aqueous and glycolic ...

  10. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (External Review Draft)

    EPA has conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of ethylene glycol monobutyl ether that will appear on the Integrated Risk Information System (IRIS) database.

  11. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (EGBE) (Interagency Science Discussion Draft)

    EPA is releasing the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessme...

  12. Material compatibility evaluataion for DWPF nitric-glycolic acid - literature review

    Glycolic acid is being evaluated as an alternative for formic and nitric acid in the DWPF flowsheet. Demonstration testing and modeling for this new flowsheet has shown that glycolic acid and glycolate has a potential to remain in certain streams generated during the production of the nuclear waste glass. A literature review was conducted to assess the impact of glycolic acid on the corrosion of the materials of construction for the DWPF facility as well as facilities downstream which may have residual glycolic acid and glycolates present. The literature data was limited to solutions containing principally glycolic acid. The reported corrosion rates and degradation characteristics have shown the following for the materials of construction: For C276 alloy, the primary material of construction for the CPC vessels, corrosion rates of either 2 or 20 mpy were reported up to a temperature of 93 deg C; For the austenitic stainless steels, 304L and 316L, variable rates were reported over a range of temperatures, varying from 2 mpy up to 200 mpy (at 100 deg C); For 690, G30, Allcorr, Ultimet and Stellite alloys no data were available; and, For relevant polymers where data are available, the data suggests that exposure to glycolic acid is not detrimental. The literature data had limited application to the DWPF process since only the storage and feed vessels, pumps and piping used to handle the glycolic acid are directly covered by the available data. These components are either 304L or 316L alloys for which the literature data is inconsistent (See Bullet 2 above). Corrosion rates in pure glycolic acid solutions also are not representative of the DWPF process streams. This stream is complex and contains aggressive species, i.e. chlorides, sulfates, mercury, as well as antifoaming agents which cumulatively have an unknown effect on the corrosion rates of the materials of construction. Therefore, testing is recommended to investigate any synergistic effects of the aggressive

  13. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    Randel, L.A.; King, C.J.

    1991-07-01

    This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.

  14. Molecular interactions and structures in ethylene glycol-ethanol and ethylene glycol-water solutions at 303 K on densities, viscosities, and refractive indices data

    Deosarkar, S. D.; Ghatbandhe, A. S.

    2014-01-01

    Molecular interactions and structural fittings in binary ethylene glycol + ethanol (EGE, x EG = 0.4111-0.0418) and ethylene glycol + water (EGW, x EG = 0.1771-0.0133) mixtures were studied through the measurement of densities (ρ), viscosities (η), and refractive indices ( n D ) at 303.15 K. Excess viscosities (η E ), molar volumes ( V m ), excess molar volumes ( V {/m E }), and molar retractions ( R M ) of the both binary systems were computed from measured properties. The measured and computed properties have been used to understand the molecular interactions in unlike solvents and structural fittings in these binary mixtures.

  15. Nanosized Mesoporous Bioactive Glass/Poly(lactic-co-glycolic Acid Composite-Coated CaSiO3 Scaffolds with Multifunctional Properties for Bone Tissue Engineering

    Mengchao Shi

    2014-01-01

    Full Text Available It is of great importance to prepare multifunctional scaffolds combining good mechanical strength, bioactivity, and drug delivery ability for bone tissue engineering. In this study, nanosized mesoporous bioglass/poly(lactic-co-glycolic acid composite-coated calcium silicate scaffolds, named NMBG-PLGA/CS, were successfully prepared. The morphology and structure of the prepared scaffolds were characterized by scanning electron microscopy and X-ray diffraction. The effects of NMBG on the apatite mineralization activity and mechanical strength of the scaffolds and the attachment, proliferation, and alkaline phosphatase activity of MC3T3 cells as well as drug ibuprofen delivery properties were systematically studied. Compared to pure CS scaffolds and PLGA/CS scaffolds, the prepared NMBG-PLGA/CS scaffolds had greatly improved apatite mineralization activity in simulated body fluids, much higher mechanical property, and supported the attachment of MC3T3 cells and enhanced the cell proliferation and ALP activity. Furthermore, the prepared NMBG-PLGA/CS scaffolds could be used for delivering ibuprofen with a sustained release profile. Our study suggests that the prepared NMBG-PLGA/CS scaffolds have improved physicochemical, biological, and drug-delivery property as compared to conventional CS scaffolds, indicating that the multifunctional property of the prepared scaffolds for the potential application of bone tissue engineering.

  16. EXPOSURE TO ETHYLENE GLYCOL MONOBUTYL ETHER AND RELATED WORKERS HABITS IN AN INK FACTORY

    W. C. Lin, H. Y. Chang, F. H. Chang

    2008-01-01

    Forty six workers from an ink factory were included in this study, in which, passive badge sampler and questionnaire interview were used to assess the concentrations of airborne exposure to ethylene glycol monobutyl ether during work shifts and to understand the subjects' working habits. The geometric mean value (95% confidence interval) of the airborne ethylene glycol monobutyl ether concentrations was 0.12(0.08-0.19)ppm, with a range of

  17. A retrospective analysis of glycol and toxic alcohol ingestion: utility of anion and osmolal gaps

    Krasowski Matthew D; Wilcoxon Rebecca M; Miron Joel

    2012-01-01

    Abstract Background Patients ingesting ethylene glycol, isopropanol, methanol, and propylene glycol ('toxic alcohols') often present with non-specific signs and symptoms. Definitive diagnosis of toxic alcohols has traditionally been by gas chromatography (GC), a technique not commonly performed on-site in hospital clinical laboratories. The objectives of this retrospective study were: 1) to assess the diagnostic accuracy of the osmolal gap in screening for toxic alcohol ingestion and 2) to de...

  18. Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice

    Niessen, M; K. Krause; Horst, I.; Staebler, N.; Klaus, S; Gaertner, S.; Kebeish, R.; Araujo, W.; Fernie, A.; Peterhansel, C.

    2012-01-01

    The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that li...

  19. Comparative study of 15% TCA peel versus 35% glycolic acid peel for the treatment of melasma

    Neerja Puri

    2012-01-01

    Background: Chemical peels are the mainstay of a cosmetic practitioner′s armamentarium because they can be used to treat some skin disorders and can provide aesthetic benefit. Objectives: To compare 15% TCA peel and 35% glycolic acid peel for the treatment of melasma. Material and Methods: We selected 30 participants of melasma aged between 20 and 50 years from the dermatology outpatient department and treated equal numbers with 15% TCA and 35% glycolic acid. Results: Subjective response as g...

  20. Comparative study of 15% TCA peel versus 35% glycolic acid peel for the treatment of melasma

    Puri, Neerja

    2012-01-01

    Background: Chemical peels are the mainstay of a cosmetic practitioner's armamentarium because they can be used to treat some skin disorders and can provide aesthetic benefit. Objectives: To compare 15% TCA peel and 35% glycolic acid peel for the treatment of melasma. Material and Methods: We selected 30 participants of melasma aged between 20 and 50 years from the dermatology outpatient department and treated equal numbers with 15% TCA and 35% glycolic acid. Results: Subjective response as g...

  1. Gas Chromatography/Electron Ionization Mass Spectrometric Analysis of Oligomeric Polyethylene Glycol Mono Alkyl Ethers

    Adebayo O. Onigbinde; Burnaby Munson; Bamidele M.W. Amos-tautua

    2013-01-01

    Polyethylene Glycol Monoalkyl Ethers, CxH2x+1 (OC2H4)n OH, (PEGMAE), are polar compounds like Polyethylene Glycols (PEG) and they undergo microbial degradation which produces toxic substances that are potentially dangerous to the environment. Therefore, the purpose of this study is to carry out proper identification and characterization of these compounds. The Electron Ionization (EI) and Chemical Ionization (CI) spectra of various PEGMAE were obtained by Gas Chromatography/Mass Spectrometry ...

  2. A simple and robust method for pre-wetting poly (lactic-co-glycolic) acid microspheres

    Wright, B; Parmar, N.; Bozec, L.; Aguayo, S. D.; Day, R. M.

    2015-01-01

    Poly (lactic-co-glycolic) acid microspheres are amenable to a number of biomedical procedures that support delivery of cells, drugs, peptides or genes. Hydrophilisation or wetting of poly (lactic-co-glycolic) acid are an important pre-requisites for attachment of cells and can be achieved via exposure to plasma oxygen or nitrogen, surface hydrolysis with NaOH or chloric acid, immersion in ethanol and water, or prolonged incubation in phosphate buffered saline or cell culture medium. The aim o...

  3. Poly(lactic-co-glycolic acid) conduit for repair of injured sciatic nerve: A mechanical analysis

    Yu, Tao; ZHAO, CHANGFU; Li, Peng; Liu, Guangyao; Luo, Min

    2013-01-01

    Tensile stress and tensile strain directly affect the quality of nerve regeneration after bridging nerve defects by poly(lactic-co-glycolic acid) conduit transplantation and autogenous nerve grafting for sciatic nerve injury. This study collected the sciatic nerve from the gluteus maximus muscle from fresh human cadaver, and established 10-mm-long sciatic nerve injury models by removing the ischium, following which poly(lactic-co-glycolic acid) conduits or autogenous nerve grafts were transpl...

  4. Evaluating the possibility of desalinization of a saline aqueous solution of diethylene glycol

    Gurbanyazov, O.A.; Khudayberenov, S.; Mamedov, M.

    1982-01-01

    A device is proposed for desalinating a saline aqueous solution of diethylene glycol based on a change in solubility of NaCl. The possibility is evaluated of desalinating the saline aqueous solution of diethylene glycol with the help of this device. Introduction into production of the device will yield a perceptible economic effect. If solar energy is used as the energy source in combination with secondary energy resource of gas production, then the effect will rise.

  5. 21 CFR 172.712 - 1,3-Butylene glycol.

    2010-04-01

    ...: (a) It is prepared by the aldol condensation of acetaldehyde followed by catalytic hydrogenation. (b... reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the Office...

  6. Two alanine aminotranferases link mitochondrial glycolate oxidation to the major photorespiratory pathway in Arabidopsis and rice.

    Niessen, Markus; Krause, Katrin; Horst, Ina; Staebler, Norma; Klaus, Stephanie; Gaertner, Stefanie; Kebeish, Rashad; Araujo, Wagner L; Fernie, Alisdair R; Peterhansel, Christoph

    2012-04-01

    The major photorespiratory pathway in higher plants is distributed over chloroplasts, mitochondria, and peroxisomes. In this pathway, glycolate oxidation takes place in peroxisomes. It was previously suggested that a mitochondrial glycolate dehydrogenase (GlcDH) that was conserved from green algae lacking leaf-type peroxisomes contributes to photorespiration in Arabidopsis thaliana. Here, the identification of two Arabidopsis mitochondrial alanine:glyoxylate aminotransferases (ALAATs) that link glycolate oxidation to glycine formation are described. By this reaction, the mitochondrial side pathway produces glycine from glyoxylate that can be used in the glycine decarboxylase (GCD) reaction of the major pathway. RNA interference (RNAi) suppression of mitochondrial ALAAT did not result in major changes in metabolite pools under standard conditions or enhanced photorespiratroy flux, respectively. However, RNAi lines showed reduced photorespiratory CO(2) release and a lower CO(2) compensation point. Mitochondria isolated from RNAi lines are incapable of converting glycolate to CO(2), whereas simultaneous overexpression of GlcDH and ALAATs in transiently transformed tobacco leaves enhances glycolate conversion. Furthermore, analyses of rice mitochondria suggest that the side pathway for glycolate oxidation and glycine formation is conserved in monocotyledoneous plants. It is concluded that the photorespiratory pathway from green algae has been functionally conserved in higher plants. PMID:22268146

  7. Effect of glycol-based coolants on the suppression and recovery of platinum fuel cell electrocatalysts

    Garsany, Yannick; Dutta, Sreya; Swider-Lyons, Karen E.

    2012-10-01

    We use cyclic and rotating disk electrode voltammetry to study glycol-based coolant formulations to show that individual constituents have either negligible or significant poisoning effects on the nanoscale Pt/carbon catalysts used in proton exchange membrane fuel cells. The base fluid in all these coolants is glycol (1, 3 propanediol), commercially available in a BioGlycol coolant formulation with an ethoxylated nonylphenol surfactant, and azole- and polyol-based non-ionic corrosion inhibitors. Exposure of a Pt/Vulcan carbon electrode to glycol-water or glycol-water-surfactant mixtures causes the loss of Pt electrochemical surface area (ECSA), but the Pt ECSA is fully recovered in clean electrolyte. Only mixtures with the azole corrosion inhibitor cause irreversible losses to the Pt ECSA and oxygen reduction reaction (ORR) activity. The Pt ECSA and ORR activity can only be recovered to within 70% of its initial values after aggressive voltammetric cycling to 1.50 V after azole poisoning. When poisoned with a glycol mixture containing the polyol corrosion inhibitor instead, the Pt ECSA and ORR activity is completely recovered by exposure to a clean electrolyte. The results suggest that prior to incorporation in a fuel cell, voltammetric evaluation of the constituents of coolant formulations is worthwhile.

  8. Reducing the corrosion rate of magnesium alloys using ethylene glycol for advanced electrochemical imaging

    Highlights: • Corrosion of AM50 was slowed in ethylene glycol solution compared with aqueous. • Water additions to ethylene glycol accelerated corrosion, enabling access to water as an oxidant. • Ethylene glycol exposure lowers corrosion activity at alloy surface enabling application of SECM. • Ferrocenemethanol (a redox active species) was successful in mapping areas of high anodic activity. - Abstract: The corrosion of an AM50 Mg alloy was studied in ethylene glycol using electrochemical and electron microscopy techniques. Switching from H2O to ethylene glycol, it was shown that the corrosion of the AM50 alloy was significantly suppressed thereby slowing H2 evolution. The corrosion of the AM50 alloy was mapped using scanning electrochemical microscopy in the feedback mode. Ferrocenemethanol can be used to expose the reactive anodic areas on the Mg alloy. These studies confirmed that studies in ethylene glycol can be used to elucidate reaction features obscured by rapid corrosion in H2O without significantly altering the mechanism and damage morphology

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

    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. PMID:27102303

  10. Characterization of gliclazide-polyethylene glycol solid dispersion and its effect on dissolution

    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

  11. AS1411 Aptamer-Decorated Biodegradable Polyethylene Glycol-Poly(lactic-co-glycolic acid) Nanopolymersomes for the Targeted Delivery of Gemcitabine to Non-Small Cell Lung Cancer In Vitro.

    Alibolandi, Mona; Ramezani, Mohammad; Abnous, Khalil; Hadizadeh, Farzin

    2016-05-01

    Molecularly targeted drug delivery systems represent a novel therapeutic strategy in the treatment of different cancers. In the present study, we have developed gemcitabine (GEM)-loaded AS1411 aptamer surface-decorated polyethylene glycol-poly(lactic-co-glycolic acid) nanopolymersome (Apt-GEM-NP) to target nucleolin-overexpressing non-small cell lung cancer (NSCLC; A549). The prepared Apt-GEM-NP showed average particle size of 128 ± 5.23 nm and spherical morphology with encapsulation efficiency and loading content of 95.32 ± 2.37% and 8.61 ± 0.27%, respectively. Apt-GEM-NP exhibited a controlled release pattern. A sustained release of drug in physiological conditions will greatly improve the chemotherapeutic efficiency of a system. Enhanced cellular uptake and the cytotoxicity of aptamer-conjugated nanoparticles (NPs) in A549 cancer cells obviously verified nucleolin-mediated receptor-based active targeting. Nucleolin-mediated internalization of the targeted polymeric NP was further confirmed by flow cytometry and fluorescence microscopy. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay clearly showed the enhanced cell proliferation inhibitory effect of AS1411-conjugated NP on account of the selective delivery of GEM to the nucleolin-overexpressing cancer cells. Our results showed that AS1411 aptamer conjugation on the surface of NP could be a potential treatment strategy for A549 as a nucleolin-overexpressing cell line. This suggests that AS1411-GEM-NPs could be potentially used for the treatment of NSCLC. PMID:27039356

  12. Preparation and characterization of PEG-albumin-curcumin nanoparticles intended to treat breast cancer

    R Thadakapally

    2016-01-01

    Full Text Available The aim of present research was to prepare novel serum stable long circulating polymeric nanoparticles for curcumin with a modification to the well known and novel nanoparticle albumin bound technology. polyethylene glycol-albumin-curcumin nanoparticles were prepared using serum albumin and poly ethylene glycol using desolvation technique. Nanoparticles were characterized for encapsulation efficiency, particle size and surface morphology. Drug excipient compatibility was determined using fourier transform infrared spectroscopy. Physical state of the drug in the formulations was known by differential scanning colorimetry. In vitrorelease and solubility of the drug from nanoparticles were determined. In vivo Drug release, tissue uptake and kupffer cell uptake was determined with optimized nanoformulation in rats after intravenous administration. Cell viability assay was determined using breast cancer cell line MD-MB-231. Entrapment efficiency for prepared nanoparticle was above 95%. The polyethylene glycol-albumin-curcumin nanoparticles exhibited an interesting release profile with small initial burst followed by slower and controlled release. Solubility of the drug from the formulation was increased. A sustained release of drug from nanoparticles was observed for 35 days in both in vitro and in vivo studies with the optimized formulation. Polyethylene glycol-albumin-curcumin nanoparticles showed lesser liver and kupffer cell uptake as compared to that of curcumin-albumin nanoparticles suggesting the bestowment of stealthness to nanoparticles with pegylation. Also, the antiproliferative activity of polyethylene glycol-albumin-curcumin nanoparticle formulation was more as compared to native curcumin. Polyethylene glycol-albumin-curcumin nanoparticles thus developed can be conveniently used in breast cancer with improved efficacy compared to conventional therapies and as an alternate to nanoparticle albumin bound technology which is used in

  13. Mechanical property and in vitro biocompatibility of brushite cement modified by polyethylene glycol

    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 [MCPM, Ca(H2PO4)2 ⋅ H2O]. PEG was introduced at 2.0 and 5.0 wt% with the liquid. Introduction of PEG resulted in marginal increase in both initial and final setting time, however, significantly affected the compressive strength. Effects of PEG incorporation on in vitro biocompatibility of brushite cements were studied by using human fetal osteoblast cells (hFOB) cells. Field emission scanning electron microscope (FESEM) images and immunohistochemical analysis indicated that pure and PEG incorporated brushite cement facilitates cell adhesion, proliferation and differentiation. Fewer cells expressed vinculin protein with increased PEG content in the cement. Cell proliferation was found to decrease with increased PEG concentration while the cell differentiation increased with PEG content. Our results provide a better understanding of in vitro biocompatibility of PEG added brushite cements that can be used to customize the cement compositions based on application need. - Highlights: ► Setting time was not altered for brushite cement with PEG addition. ► hFOB cell proliferation was found to decrease with increased PEG concentration in brushite cement. ► Enhanced ALP activity was noticed with addition of PEG in brushite cements.

  14. Mucoadhesive plasticized system of branched poly(lactic-co-glycolic acid) with aciclovir.

    Snejdrova, Eva; Drastik, Martin; Dittrich, Milan; Kastner, Petr; Nguyenova, Jana

    2016-10-01

    Commercially available antibacterial semisolid preparations intended for topical application provide only short-term drug release. A sustained kinetics is possible by exploitation of a biodegradable polymer carrier. The purpose of this work is to formulate a mucoadhesive system with aciclovir (ACV) based on a solid molecular dispersion of this drug in poly(lactic-co-glycolic acid) branched on tripenterythritol (PLGA/T). The ACV incorporation into PLGA/T was carried out either by solvent method, or melting method, or plasticization method using various plasticizers. The drug-polymer miscibility, plasticizer efficiency and content of residual solvent were found out employing DSC. Viscosity was measured at the shear rate range from 0.10 to 10.00 s(-1) at three temperatures and data were analyzed by Newtonian model. The mucoadhesive properties were ascertained in the tensile test on a mucin substrate. The amount of ACV released was carried out in a wash-off dissolution test. The DSC results indicate a transformation of crystalline form of ACV into an amorphous dissolved in branched polyester carrier, and absence of methyl formate residuals in formulation. All the tested plasticizers are efficient at Tg depression and viscosity decrease. The non-conventional ethyl pyruvate possessing supportive anti-inflammatory activity was evaluated as the most suitable plasticizer. The ACV release was strongly dependent on the ethyl pyruvate concentration and lasted from 1 to 10 days. The formulated PLGA/T system with ACV exhibits increased adhesion to mucosal hydrophilic surfaces and prolonged ACV release controllable by degradation process and viscosity parameters. PMID:26925606

  15. Intercalation behavior of poly(ethylene glycol) in organically modified montmorillonite

    Zhu, Shipeng; Peng, Hongmei; Chen, Jinyao; Li, Huilin; Cao, Ya; Yang, Yunhua; Feng, Zhihai

    2013-07-01

    In this paper, two kinds of organically modified montmorillonite (OMMT) were prepared using alkylammonium surfactants with different alkyl chain numbers. XRD results showed the interlayer spacing of OMMT increased with low concentration surfactants. With further increasing the surfactants concentration, the interlayer spacing of OMMT was unchanged. Meanwhile, FTIR was used to characterize the local environments of surfactants in the interlayer space of OMMT. The results suggested that the double chain surfactant D-18 preferred to adopt highly ordered conformation compared with single chain surfactant S-18 in interlayer space of OMMT. It indicated that the surface property of the OMMT is affected by the concentration and configuration of the intercalated surfactants. Moreover, the effect of the OMMT type, or more particularly the chemical nature of the organic modifier in the interlayer spacing and the poly(ethylene glycol) (PEG) concentration onintercalation behavior of PEG chains in OMMT were investigated with XRD and DSC.The results indicated that PEG chains could not intercalate into Na-MMT when the surfactants were saturated in interlayer space of Na-MMT. PEG chains could intercalate into the interlayer space of SM when the S-18 concentration was lower than 2.00CEC, implying that the low surfactant concentration modified SM provided a better environment (presumably through the balanced hydrophobic and hydrophilic surfaces) for the PEG intercalation as well. However, PEG did not intercalate into the interlayer space of DM when the D-18 concentration was higher than 1.00CEC. It could be attributed to the hydrophobic double alkyl chains of DM increased with D-18. The increased hydrophobic properties in the interlayer space of 1.50DM hybrids can prevent the intercalation of hydrophilic PEG.

  16. Characterization of nephritogenic IgA immune complexes separated by polyethylene glycol

    Imai, H.; Rifai, A.

    1986-03-05

    The size of IgA immune complexes (IgA-IC) plays an important role in the pathogenesis of experimental IgA nephropathy. The ability of different concentrations (3.5%, 5% and 7% w/v) of polyethylene glycol (PEG) to selectively precipitate IgA-IC with defined size, was examined using convalently cross-linked /sup 125/I-radiolabelled IgA-IC. These complexes were prepared with purified IgA anti-dinitrophenyl (DNP) antibodies and bis-DNP-pimelic acid ester. Size analysis of IgA-IC by gradient polyacrylamide gel electrophoresis (GPAGE) revealed a composition of 33% large-size (> 2 x 10/sup 6/ mw), 39% intermediate-size (4-20 x 10/sup 5/ mw), and 28% mixture of dimer and monomer IgA. The standard 3.5% PEG precipitated less than 7% of large- and intermediate-size IgA-IC. In contrast, 5% and 7% PEG precipitated 40% and 100% of large-size complexes, respectively. The 7% PEG was also effective in precipitating (40%) of the intermediate-size complexes. The correlation between PEG concentration and size of the precipitated IgA-IC was further confirmed by GPAGE and quantitative autoradiography of resolubilized PEG precipitates of discrete size IgA-IC obtained by gel filtration. They conclude the standard 3.5% PEG is inappropriate for precipitation of IgA-IC and recommend the use of 7% PEG for the detection of intermediate- and large-size IgA-IC.

  17. Feasibility of poly(ethylene glycol) derivatives as diagnostic drug carriers for tumor imaging.

    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. PMID:26869546

  18. Online Aerosol Mass Spectrometry of Single Micrometer-Sized Particles Containing Poly(ethylene glycol)

    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.

  19. Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)/clay composites

    Highlights: → We synthesized macroporous composites of poly(GMA-co-EGDMA) and either raw or acid modified clay. → Morphological, textural and thermal properties of the composite with acid modified clay were significantly changed with retained macroporosity. → Composite with raw clay has enhanced thermal stability. - Abstract: In this study, macroporous composites of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) i.e. poly(GMA-co-EGDMA) and clay were prepared by radical suspension copolymerization. The composites with either raw (S0) or acid-modified clay (SA) were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric (TG) and textural analysis. The morphological, textural and thermal properties of the composite with raw clay (CP-S0) differed slightly from those of the copolymer (CP), with exception of the thermal stability expressed in the shifting of the initial degradation temperature from 125 deg. C for CP to 210 deg. C for CP-S0. On the other hand, composite with modified clay (CP-SA) was a material with significantly changed morphology, porous structure parameters and a qualitatively different thermal behavior in comparison to CP and CP-S0. CP-SA had mass residue, after heating at 600 deg. C, three times higher than the amount of SA introduced into the reaction system. This indicates a different manner of incorporation of SA, compared to S0, into the composite. Both the obtained composites retained their macroporosity and might be used in all applications that involve macroporous copolymers and, due to the altered thermal properties, their application may be extended.

  20. Poly-lactic-glycolic-acid surface nanotopographies selectively decrease breast adenocarcinoma cell functions

    The ability of poly(lactic-co-glycolic acid) (PLGA, 50:50 PLG/PGA, wt%) nanotopographies to decrease lung epithelial carcinoma cell functions (including adhesion, proliferation, apoptosis and vascular endothelial growth factor (VEGF) secretion) has been previously reported. Specifically, results demonstrated decreased lung epithelial carcinoma cell VEGF synthesis on 23 nm surface-featured PLGA compared to traditional nanosmooth PLGA. However, clearly, different cell lines could have different behaviors on similar biomaterials. Thus, to investigate the universality of nanopatterned PLGA substrates to inhibit numerous cancer cell functions, here, breast epithelial adenocarcinoma cell (MCF-7) adhesion, proliferation, apoptosis and VEGF secretion were determined on different PLGA nanometer surface topographies. To isolate surface nanotopographical effects from all other surface properties, PLGA surfaces with various nanotopographies but similar chemistry and hydrophobicity were fabricated here. Atomic force microscopy (AFM) verified the varied nanotopographies on the PLGA surfaces prepared in this study. Importantly, results demonstrated for the first time significantly decreased breast adenocarcinoma cell functions (including decreased proliferation rate, increased apoptosis and decreased VEGF synthesis) on 23 nm featured PLGA surfaces compared to all other PLGA surface topographies fabricated (specifically, nanosmooth, 300 and 400 nm surface-featured PLGA surfaces). In contrast, healthy breast epithelial cells proliferated more (24%) on the 23 nm featured PLGA surfaces compared to all other PLGA samples. In summary, these results provided further insights into understanding the role PLGA surface nanotopographies can have on cancer cell functions and, more importantly, open the possibility of using polymer nanotopographies for a wide range of anticancer regenerative medicine applications (without resorting to the use of chemotherapeutics). (paper)

  1. Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

    K.L. Bessa

    2011-08-01

    Full Text Available This study was designed to evaluate the effect of drag reducer polymers (DRP on arteries from normotensive (Wistar and spontaneously hypertensive rats (SHR. Polyethylene glycol (PEG 4000 at 5000 ppm was perfused in the tail arterial bed with (E+ and without endothelium (E- from male, adult Wistar (N = 14 and SHR (N = 13 animals under basal conditions (constant flow at 2.5 mL/min. In these preparations, flow-pressure curves (1.5 to 10 mL/min were constructed before and 1 h after PEG 4000 perfusion. Afterwards, the tail arterial bed was fixed and the internal diameters of the arteries were then measured by microscopy and drag reduction was assessed based on the values of wall shear stress (WSS by computational simulation. In Wistar and SHR groups, perfusion of PEG 4000 significantly reduced pulsatile pressure (Wistar/E+: 17.5 ± 2.8; SHR/E+: 16.3 ± 2.7%, WSS (Wistar/E+: 36; SHR/E+: 40% and the flow-pressure response. The E- reduced the effects of PEG 4000 on arteries from both groups, suggesting that endothelial damage decreased the effect of PEG 4000 as a DRP. Moreover, the effects of PEG 4000 were more pronounced in the tail arterial bed from SHR compared to Wistar rats. In conclusion, these data demonstrated for the first time that PEG 4000 was more effective in reducing the pressure-flow response as well as WSS in the tail arterial bed of hypertensive than of normotensive rats and these effects were amplified by, but not dependent on, endothelial integrity. Thus, these results show an additional mechanism of action of this polymer besides its mechanical effect through the release and/or bioavailability of endothelial factors.

  2. Thermal properties and physicochemical behavior in aqueous solution of pyrene-labeled poly(ethylene glycol-polylactide conjugate

    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

  3. Myocardial matrix–polyethylene glycol hybrid hydrogels for tissue engineering

    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. (paper)

  4. Effects of Grafting Density and Film Thickness on the Adhesion of Staphylococcus epidermidis to Poly(2-hydroxy ethyl methacrylate) and Poly(poly(ethylene glycol)methacrylate) Brushes.

    Ibanescu, Sorin-Alexandru; Nowakowska, Justyna; Khanna, Nina; Landmann, Regine; Klok, Harm-Anton

    2016-05-01

    Thin polymer films that prevent the adhesion of bacteria are of interest as coatings for the development of infection-resistant biomaterials. This study investigates the influence of grafting density and film thickness on the adhesion of Staphylococcus epidermidis to poly(poly(ethylene glycol)methacrylate) (PPEGMA) and poly(2-hydroxyethyl methacrylate) (PHEMA) brushes prepared via surface-initiated atom transfer radical polymerization (SI-ATRP). These brushes are compared with poly(ethylene glycol) (PEG) brushes, which are obtained by grafting PEG onto an epoxide-modified substrate. Except for very low grafting densities (ρ = 1%), crystal violet staining experiments show that the PHEMA and PPEGMA brushes are equally effective as the PEG-modified surfaces in preventing S. epidermis adhesion and do not reveal any significant variations as a function of film thickness or grafting density. These results indicate that brushes generated by SI-ATRP are an attractive alternative to grafted-onto PEG films for the preparation of surface coatings that resist bacterial adhesion. PMID:26757483

  5. Chemical and enzymatic stability of amino acid prodrugs containing methoxy, ethoxy and propylene glycol linkers.

    Gupta, Deepak; Gupta, Sheeba Varghese; Lee, Kyung-Dall; Amidon, Gordon L

    2009-01-01

    We evaluated the chemical and enzymatic stabilities of prodrugs containing methoxy, ethoxy and propylene glycol linkers in order to find a suitable linker for prodrugs of carboxylic acids with amino acids. l-Valine and l-phenylalanine prodrugs of model compounds (benzoic acid and phenyl acetic acid) containing methoxy, ethoxy and propylene glycol linkers were synthesized. The hydrolysis rate profile of each compound was studied at physiologically relevant pHs (1.2, 4, 6 and 7.4). Enzymatic hydrolysis of propylene glycol containing compounds was studied using Caco-2 homogenate as well as purified enzyme valacyclovirase. It was observed that the stability of the prodrugs increases with the linker length (propyl > ethyl > methyl). The model prodrugs were stable at acidic pH as compared to basic pH. It was observed that the prodrug with the aliphatic amino acid promoiety was more stable compared to its aromatic counterpart. The comparison between benzyl and the phenyl model compounds revealed that the amino acid side chain is significant in determining the stability of the prodrug whereas the benzyl or phenyl carboxylic acid had little or no effect on the stability. The enzymatic activation studies of propylene glycol linker prodrug in the presence of valacyclovirase and cell homogenate showed faster generation of the parent drug at pH 7.4. The half-life of prodrugs at pH 7.4 was more than 12 h, whereas in the presence of cell homogenate the half-lives were less than 1 h. Hydrolysis by Caco-2 homogenate generated the parent compound in two steps, where the prodrug was first converted to the intermediate, propylene glycol benzoate, which was then converted to the parent compound (benzoic acid). Enzymatic hydrolysis of propylene glycol containing prodrugs by valacyclovirase showed hydrolysis of the amino acid ester part to generate the propylene glycol ester of model compound (propylene glycol benzoate) as the major product. The amino acid prodrugs containing methoxy

  6. Effects of PVP on the preparation and growth mechanism of monodispersed Ni nanoparticles

    2008-01-01

    Monodispersed Ni nanoparticles were successfully prepared by chemical reduction with hydrazine hydrate in ethylene glycol.The effect of the amount of polyvinylpyrrolidone (PVP-K30) on the preparation of Ni nanoparticles was investigated.X-ray diffraction (XRD),transmission electron microscopy (TEM),and high resolution transmission electron microscopy (HRTEM) were employed to characterize the nickel particles are spherical in shape and are not agglomerated.A possible extensive mechanism of nickel nanoparticle formation has been suggested.

  7. Preparation of two-component polyurethane coatings from bleached liquefied wood

    Pori, Pavel; Tavzes, Črtomir; Hrastnik, David; Budija, Franc; Pavlič, Matjaž; Petrič, Marko; Cheumani-Yona, Arnaud Maxime

    2016-01-01

    Liquefied wood-based polyurethane wood coatings of an aesthetically acceptable light colour were prepared and characterised. Liquefied black poplar wood was obtained by solvolysis in a polyethylene glycol/glycerol mixture, and it was bleached with hydrogen peroxide. The bleaching treatment converted liquefied wood from a dark brown to a yellowish product. Polyurethane films were prepared by the curing of liquefied wood with polymeric diphenylmethane diisocyanate or trimethylolpropane toluene ...

  8. Glycol-assisted construction of three-dimensionally ordered macroporous ZnO-Cu2O-TiO2 with enhanced photocatalytic properties

    Yang, Renchun; Lu, Xiaojia; Zhang, Huan; Tao, Tingxian; Ren, Yiming; Li, Fang; Zhu, Lingting

    2016-01-01

    The Zn and Cu bi-components co-modified ZnO-Cu2O-TiO2 composites with 3DOM structure were constructed via a facile glycol-assisted sol-gel method. The morphology, composition and structure of the prepared samples with five different Cu/Zn mass ratios were characterized by XRD, SEM, XPS, UV-VIS DRS and N2 adsorption-desorption. The results indicate that the oxygen vacancies contents of the as-prepared catalysts are heavily dependent on the Cu/Zn mass ratios. Among the five catalysts, the Zn0.06-Cu0.14 sample shows the highest oxygen vacancies content. These findings reveal that the introduction of a certain proportional ZnO and Cu2O can promote the capturing efficiency of visible light and the charge carrier separation, ultimately resulting in an enhanced photodecoloration performance of MB.

  9. Glycol ethers--validation procedures for tube/pump and dosimeter monitoring methods.

    Langhorst, M L

    1984-06-01

    Methods were developed and validated for personal monitoring of exposures to airborne glycol ethers, both short-term and long-term time-weighted-averages. Either a 600 mg charcoal tube or a 780 mg silica gel tube is recommended for monitoring nine glycol ethers, depending upon the humidity and other organic compounds to be monitored. The charcoal tube allows maximum sensitivity and is unaffected by high humidity conditions. Two-phase solvent desorption with CS2 and water allows aqueous phase recoveries of DOWANOL EM, PM, EE, DM, DPM, and TM glycol ethers. DOWANOL EB, DB and TPM glycol ethers are partitioned between the two layers, necessitating chromatographic analysis of both layers. The silica gel tube method can be used to monitor all nine glycol ethers tested, but is affected by high humidity conditions, resulting in significant breakthrough of the more volatile glycol ethers. The 3M organic vapor monitor can accurately and conveniently determine exposure concentrations for DOWANOL EM, EE, and PM glycol ethers, but sensitivities may be inadequate for sampling periods less than one hour. These methods were validated at levels down to 0.1 times the Dow internal exposure guidelines for those substances with Dow exposure guidelines and well above the current ACGIH and OSHA guidelines. This paper also illustrates validation procedures for tube/pump and dosimeter methods, allowing good definition of method accuracy and precision. Some screening experiments are described for diffusional dosimeters to check the most important parameters in a minimum of time. This methodology will allow assessment of human airborne exposures relative to the new toxicology data available on animals. PMID:6331145

  10. Effect of osteoblastic culture conditions on the structure of poly(DL-lactic-co-glycolic acid) foam scaffolds

    Goldstein, A. S.; Zhu, G.; Morris, G. E.; Meszlenyi, R. K.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    Poly(DL-lactic-co-glycolic acid) (PLGA) foams are an osteoconductive support that holds promise for the development of bone tissue in vitro and implantation into orthopedic defects. Because it is desirable that foams maintain their shape and size, we examined a variety of foams cultured in vitro with osteoblastic cells. Foams were prepared with different porosities and pore sizes by the method of solvent casting/porogen leaching using 80, 85, and 90 wt% NaCl sieved with particle sizes of 150-300 and 300-500 microm and characterized by mercury intrusion porosimetry. Foams seeded with cells were found to have volumes after 7 days in static culture that decreased with increasing porosity: the least porous exhibited no change in volume while the most porous foams decreased by 39 +/- 10%. In addition, a correlation was observed between decreasing foam volume after 7 days in culture and decreasing internal surface area of the foams prior to seeding. Furthermore, foams prepared with the 300-500 microm porogen had lower porosities, greater mean wall thicknesses between adjacent pores, and larger volumes after 7 days in culture than those prepared with the smaller porogen. Two culture conditions for maintaining cells, static and agitated (in a rotary vessel), were found to have similar influences on foam size, cell density, and osteoblastic function for 7 and 14 days in culture. Finally, we examined unseeded foams in aqueous solutions of pH 3.0, 5.0, and 7.4 and found no significant decrease in foam size with degradation. This study demonstrates that adherent osteoblastic cells may collapse very porous PLGA foams prepared by solvent casting/particulate leaching: a potentially undesirable property for repair of orthopedic defects.

  11. Controlled release of drug and better bioavailability using poly(lactic acid-co-glycolic acid) nanoparticles.

    Pandey, Sanjeev K; Patel, Dinesh K; Maurya, Akhilendra K; Thakur, Ravi; Mishra, Durga P; Vinayak, Manjula; Haldar, Chandana; Maiti, Pralay

    2016-08-01

    Tamoxifen (Tmx) embedded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (PLGA-Tmx) is prepared to evaluate its better DNA cleavage potential, cytotoxicity using Dalton's lymphoma ascite (DLA) cells and MDA-MB231 breast cancer cells. PLGA-Tmx nanoparticles are prepared through emulsified nanoprecipitation technique with varying dimension of 17-30nm by changing the concentrations of polymer, emulsifier and drug. Nanoparticles dimension are measured through electron and atomic force microscopy. Interactions between tamoxifen and PLGA are verified through spectroscopic and calorimetric methods. PLGA-Tmx shows excellent DNA cleavage potential as compared to pure Tmx raising better bioavailability. In vitro cytotoxicity studies indicate that PLGA-Tmx reduces DLA cells viability up to ∼38% against ∼15% in pure Tmx. Hoechst stain is used to detect apoptotic DLA cells through fluorescence imaging of nuclear fragmentation and condensation exhibiting significant increase of apoptosis (70%) in PLGA-Tmx vis-à-vis pure drug (58%). Enhanced DNA cleavage potential, nuclear fragmentation and condensation in apoptotic cells confirm greater bioavailability of PLGA-Tmx as compared to pure Tmx in terms of receptor mediated endocytosis. Hence, the sustained release kinetics of PLGA-Tmx nanoparticles shows much better anticancer efficacy through enhanced DNA cleavage potential and nuclear fragmentation and, thereby, reveal a novel vehicle for the treatment of cancer. PMID:27112980

  12. Vitamin C and Poly(ethylene glycol) Protect Concentrated Poly(vinyl alcohol) Solutions against Radiation Cross-linking

    There is a need for an injectable material to augment damaged cartilage. We propose to make such self-associating poly(vinyl alcohol) (PVA) hydrogels. Physical associations can be formed in PVA using a gellant such as polyethylene glycol (PEG). The injectability of PVA solutions is compromised when sterilized due to chemical cross-linking. We hypothesized that an anticross-linking agent could prevent cross-linking of irradiated PVA solutions. PVA (17.5 wt/v %, MW= 115,000 g/mol) was prepared in water at 90 degree. PEG (MW=400 g/mol) was added at a ratio of PEG unit to PVA unit of 17, 86, 290, and 639 mol/mol. PVA solutions (17.5 wt/v %, MW= 16,000, 61,000, 81,000 and 115,000 g/mol) were also prepared. Vitamin C was added at a molar ratio of vitamin C to PVA unit of 0.75-10.4. Solutions were poured into syringes and γ-irradiated. The viscosity of injectable solutions was determined by using the bubble tube. Gel content of cross-linked samples was measured by boiling gels in water for 6 hours, drying at 90 degree and calculating the ratio of dry weight to 'as is' weight

  13. Ti/TiO2 nanotube array electrode as a new sensor to photoelectrocatalytic determination of ethylene glycol

    Reza Ojani; Akbar Khanmohammadi; Jahan-Bakhsh Raoof

    2016-02-01

    The photoelectrocatalytic oxidation behaviour of ethylene glycol (EG) was studied in the present work using the TiO2-modified Ti foil (Ti/TiO2) electrode. The Ti/TiO2 nanotube array (Ti-NTA) electrode was prepared by anodizing of the Ti foil in the HF aqueous solution (0.2% v/v). The anodization was conducted in the constant 30 Vfor 2 h, and then the as-prepared Ti-NTA electrode was calcinated at 50°C for 2 h. The surface morphology of Ti-NTA electrode was studied using scanning electron microscopy images. For EG determination, the photocurrent of EG (EG oxidation current in the UV irradiation) was assessed using the hydrodynamic photoamperometric method in the phosphate buffers. Ultimately, the optimum conditions of EG determination were studied in various pH values andapplied bias potentials, and the pH=3.0 and =1.0 V (vs. reference electrode) were determined as the optimum conditions. It was found that the photocurrent of EG was linearly dependent on the concentration of EG in the range of 3.0 × 10−5 to 0.88 mol l−1, and the detection limit of EG determination was found to be 7.2 × 10−6 mol l−1 (3).

  14. Protective effect of recombinant staphylococcal enterotoxin A entrapped in polylactic-co-glycolic acid microspheres against Staphylococcus aureus infection

    Chen Liben

    2012-03-01

    Full Text Available Abstract Staphylococcus aureus is an important cause of nosocomial and community-acquired infections in humans and animals, as well as the cause of mastitis in dairy cattle. Vaccines aimed at preventing S. aureus infection in bovine mastitis have been studied for many years, but have so far been unsuccessful due to the complexity of the bacteria, and the lack of suitable vaccine delivery vehicles. The current study developed an Escherichia coli protein expression system that produced a recombinant staphylococcal enterotoxin A (rSEA encapsulated into biodegradable microparticles generated by polylactic-co-glycolic acid (PLGA dissolved in methylene chloride and stabilized with polyvinyl acetate. Antigen loading and surface properties of the microparticles were investigated to optimize particle preparation protocols. The prepared PLGA-rSEA microspheres had a diameter of approximately 5 μm with a smooth and regular surface. The immunogenicity of the PLGA-rSEA vaccine was assessed using mice as an animal model and showed that the vaccine induced a strong humoral immune response and increased the percent survival of challenged mice and bacterial clearance. Histological analysis showed moderate impairment caused by the pathogen upon challenge afforded by immunization with PLGA-rSEA microspheres. Antibody titer in the sera of mice immunized with PLGA-rSEA microparticles was higher than in vaccinated mice with rSEA. In conclusion, the PLGA-rSEA microparticle vaccine developed here could potentially be used as a vaccine against enterotoxigenic S. aureus.

  15. Effects of Propylene Glycol Alginate and Sucrose Esters on the Physicochemical Properties of Modified Starch-Stabilized Beverage Emulsions

    Kok Whye Cheong

    2014-06-01

    Full Text Available This study was conducted to investigate the effect of main emulsion components namely, modified starch, propylene glycol alginate (PGA, sucrose laurate and sucrose stearate on creaming index, cloudiness, average droplet size and conductivity of soursop beverage emulsions. Generally, the use of different emulsifiers or a mixture of emulsifiers has a significant (p < 0.05 effect on the response variables studied. The addition of PGA had a significant (p < 0.05 effect on the creaming index at 55 °C, while PGA-stabilized (PGA1 emulsions showed low creaming stability at both 25 °C and 55 °C. Conversely, the utilization of PGA either as a mixture or sole emulsifier, showed significantly (p < 0.05 higher cloudiness, as larger average droplet size will affect the refractive index of the oil and aqueous phases. Additionally, the cloudiness was directly proportional to the mean droplet size of the dispersed phase. The inclusion of PGA into the formulation could have disrupted the properties of the interfacial film, thus resulting in larger droplet size. While unadsorbed ionized PGA could have contributed to higher conductivity of emulsions prepared at low pH. Generally, emulsions prepared using sucrose monoesters or as a mixture with modified starch emulsions have significantly (p < 0.05 lower creaming index and conductivity values, but higher cloudiness and average droplet size.

  16. A novel strategy for the preparation of porous microspheres and its application in peptide drug loading.

    Wei, Yi; Wang, Yuxia; Zhang, Huixia; Zhou, Weiqing; Ma, Guanghui

    2016-09-15

    A new strategy is developed to prepare porous microspheres with narrow size distribution for peptides controlled release, involving a fabrication of porous microspheres without any porogens followed by a pore closing process. Amphiphilic polymers with different hydrophobic segments (poly(monomethoxypolyethylene glycol-co-d,l-lactide) (mPEG-PLA), poly(monomethoxypolyethylene glycol-co-d,l-lactic-co-glycolic acid) (mPEG-PLGA)) are employed as microspheres matrix to prepare porous microspheres based on a double emulsion-premix membrane emulsification technique combined with a solvent evaporation method. Both microspheres possess narrow size distribution and porous surface, which are mainly caused by (a) hydrophilic polyethylene glycol (PEG) segments absorbing water molecules followed by a water evaporation process and (b) local explosion of microspheres due to fast evaporation of dichloromethane (MC). Importantly, mPEG-PLGA microspheres have a honeycomb like structure while mPEG-PLA microspheres have a solid structure internally, illustrating that the different hydrophobic segments could modulate the affinity between solvent and matrix polymer and influence the phase separation rate of microspheres matrix. Long term release patterns are demonstrated with pore-closed microspheres, which are prepared from mPEG-PLGA microspheres loading salmon calcitonin (SCT). These results suggest that it is potential to construct porous microspheres for drug sustained release using permanent geometric templates as new porogens. PMID:27285778

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

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

  18. Construction and molecular analysis of genetically modified C 3 plants expressing a glycolate oxidizing pathway inside the chloroplast

    Kebeish, Rashad Mohamed Ahmed

    2006-01-01

    Metabolism of glycolate via the photorespiratory pathway in C3 plants consumes not only ATP and reducing equivalents but results also in approximately 25% loss of the carbon from glycolate. In the present study, a novel biochemical pathway for the metabolism of glycolate was established in the chloroplast of Arabidopsis thaliana plants. The new pathway aims to increase the CO2 concentration in the vicinity of Rubisco thereby suppressing photorespiration in C3 plants. The pathway is derived fr...

  19. Engineering Poly(ethylene glycol) Materials to Promote Cardiogenesis

    Smith, Amanda Walker

    Heart failure is one of the leading causes of death worldwide, and the current costs of treatment put a significant economic burden on our societies. After an infarction, fibrotic tissue begins to form as part of the heart failure cascade. Current options to slow this process include a wide range of pharmaceutical agents, and ultimately the patient may require a heart transplant. Innovative treatment approaches are needed to bring down costs and improve quality of life. The possibility of regenerating or replacing damaged tissue with healthy cardiomyocytes is generating considerable excitement, but there are still many obstacles to overcome. First, while cell injections into the myocardium have demonstrated slight improvements in cardiac function, the actual engraftment of transplanted cells is very low. It is anticipated that improving engraftment will boost outcomes. Second, cellular differentiation and reprogramming protocols have not yet produced cells that are identical to adult cardiomyocytes, and immunogenicity continues to be a problem despite the advent of autologously derived induced pluripotent stem cells. This dissertation will explore biomaterials approaches to addressing these two obstacles. Tissue engineering scaffolds may improve cell engraftment by providing bioactive factors, preventing cell anoikis, and reducing cell washout by blood flow. Poly(ethylene glycol) (PEG) is often used as a coating to reduce implant rejection because it is highly resistant to protein adsorption. Because fibrosis of a material in contact with the myocardium could cause arrhythmias, PEG materials are highly relevant for cardiac tissue engineering applications. In Chapter 2, we describe a novel method for crosslinking PEG microspheres around cells to form a scaffold for tissue engineering. We then demonstrate that HL-1 cardiomyocyte viability and phenotype are retained throughout the fabrication process and during the first 7 weeks of culture. In the third chapter of the

  20. Comparison between properties of polyurethane nano composites prepared by two different methods

    In this work, a thermoplastic polyurethane elastomer model based on polytetramethylene glycol. toluene diisocyanate and 1,4-butanediol was selected and synthesized. According to this model two types of polyurethane nano composites were prepared by in situ polymerization and melt intercalation procedures. The organo-modified nano clay was used in nano composites samples in 0.4 weight percent level. The prepared nano composites were studied by WAXD, tensile and thermal analysis. Thermal properties of the nano composites were higher than those of pure polyurethane elastomers. Nano composites prepared via melt intercalation method showed a lower tensile strength and hardness than those prepared through in situ polymerization method

  1. Comparative Evaluation Of Topical Preparations In Treatment of Melasma

    Pandhi Roma

    2002-01-01

    Full Text Available Fifty patients of melasma were randomly taken up for the study and were divided into five treatment groups of 10 patients each. Patients of these groups received clobetasol propionate 0.05% (group I, tretinoin 0.025% (group II, hydroquinone 2% (group III, bebzoyl peroxide 5% (group IV and glycolic acid 10% (group V. Pretreatment evolution was done with MASI (melasma area severity index scoring and photographic records. Patients were treated for 3 months and the preparations were found to be equally compatible to our patients. However, effectiveness on an average was higher for clobetasol (80% and tretinoin (62%, though hydroquinone (48%, benzoyal peroxide (41% and glycolic acid (30% also showed fairly good results. Our study broadens the therapeutic spectrum of melasm by using agents with different mechanisms of action.

  2. Congenital malformation and maternal occupational exposure to glycol ethers. Occupational Exposure and Congenital Malformations Working Group.

    Cordier, S; Bergeret, A; Goujard, J; Ha, M C; Aymé, S; Bianchi, F; Calzolari, E; De Walle, H E; Knill-Jones, R; Candela, S; Dale, I; Dananché, B; de Vigan, C; Fevotte, J; Kiel, G; Mandereau, L

    1997-07-01

    Glycol ethers are found in a wide range of domestic and industrial products, many of which are used in women's work environments. Motivated by concern about their potential reproductive toxicity, we have evaluated the risk of congenital malformations related to glycol ether exposure during pregnancy as part of a multicenter case-control study, conducted in six regions in Europe. The study comprised 984 cases of major congenital malformations and 1,134 controls matched for place and date of birth. Interviews of the mothers provided information about occupation during pregnancy, sociodemographic variables, and other potential risk factors (medical history, tobacco, alcohol, drugs). A chemist specializing in glycol ethers evaluated exposure during pregnancy, using the job description given by the mother, without knowledge of case or control status. We classified malformations into 22 subgroups. The overall odds ratio (OR) of congenital malformation associated with glycol ether exposure was 1.44 [95% confidence interval (CI) = 1.10-1.90], after adjustment for several potential confounders. The association with exposure to glycol ethers appeared particularly strong in three subgroups: neural tube defects (OR = 1.94; 95% CI = 1.16-3.24), multiple anomalies (OR = 2.00; 95% CI = 1.24-3.23), and cleft lip (OR = 2.03; 95% CI = 1.11-3.73). In this last subgroup, risk, especially of an isolated defect, tended to increase with level of exposure. PMID:9209847

  3. Indirect detection of ethylene glycol oligomers using a contactless conductivity detector in capillary liquid chromatography.

    Takeuchi, Toyohide; Sedyohutomo, Anang; Lim, Lee Wah

    2009-07-01

    Ethylene glycol oligomers were visualized by indirect conductimetric detection based on dilution of the mobile phase due to the analytes. A high electrical conductivity background was maintained by the addition of 5 mM sodium nitrate in the mobile phase, and the analytes were visualized by decreases in the background when they eluted. A capacitively coupled contactless conductivity detector was convenient to monitor effluents from the microcolumn with minimum extra-column band broadening. The signals as negative peaks were linear to the concentration of the analytes, and a concentration detection limit of 0.025% was achieved for tetraethylene glycol at S/N=3, corresponding to the mass detection limit of 38 ng for 0.15 microl injection. The logarithm of the retention factor of ethylene glycol oligomers was linear to the degree of polymerization (DP) as well as to the acetonitrile composition in the mobile phase. These situations allowed us to estimate the DP of eluted ethylene glycol oligomers by using a few oligomers with known DP. The dynamic reserve, defined as the ratio of the background to its noise level achieved under the present conditions, was 2.3 x 10(5) which was much larger than that achieved by UV absorption detection. The present method was applied to profile ethylene glycol oligomers contained in commercially available PEG reagents. PMID:19609021

  4. First report of suspected ethylene glycol poisoning in 2 dogs in South Africa : clinical communication

    N. Keller

    2005-06-01

    Full Text Available Ethylene glycol (anti-freeze toxicity is a serious emergency in both veterinary and human medicine. Ethylene glycol (E/G is the active anti-freeze principle in radiator water additives. It is odourless, colourless and has a sweet taste. As little as 5 mℓ or 20 mℓ is sufficient to kill a cat or a dog, respectively. Ethylene glycol is rapidly absorbed and metabolised in the liver to oxalate, which is deposited as calcium oxalate in the kidneys causing irreversible damage. This report describes 2 dogs that were suspected to have ingested ethylene glycol. The report contains a description of the 3 stages of ethylene glycol toxicity as well as a short discussion of the treatment. Public awareness about the dangers of anti-freeze will help in limiting exposure of pets and humans to this potentially fatal toxin. Veterinarians need to be aware of anti-freeze toxicity as delayed recognition and treatment will lead to the death of the patient.

  5. Electrochemical corrosion behavior of AZ91D alloy in ethylene glycol

    Fekry, A.M. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)], E-mail: hham4@hotmail.com; Fatayerji, M.Z. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

    2009-11-01

    The effect of concentration on the corrosion behavior of Mg-based alloy AZ91D was investigated in ethylene glycol-water solutions using electrochemical techniques i.e. potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface examination via scanning electron microscope (SEM) technique. This can provide a basis for developing new coolants for magnesium alloy engine blocks. Corrosion behavior of AZ91D alloy by coolant is important in the automotive industry. It was found that the corrosion rate of AZ91D alloy decreased with increasing concentration of ethylene glycol. For AZ91D alloy in chloride >0.05 M or fluoride <0.05 M containing 30% ethylene glycol solution, they are more corrosive than the blank (30% ethylene glycol-70% water). However, at concentrations <0.05 for chloride or >0.05 M for fluoride containing ethylene glycol solution, some inhibition effect has been observed. The corrosion of AZ91D alloy in the blank can be effectively inhibited by addition of 0.05 mM paracetamol that reacts with AZ91D alloy and forms a protective film on the surface at this concentration as confirmed by surface examination.

  6. Synthesis, characterization, and evaluation of paclitaxel loaded in six-arm star-shaped poly(lactic-co-glycolic acid

    Chen Y

    2013-11-01

    Full Text Available Yongxia Chen,1,3,* Ziying Yang,1,* Chao Liu,1 Cuiwei Wang,1 Shunxin Zhao,2 Jing Yang,1 Hongfan Sun,1 Zhengpu Zhang,2 Deling Kong,1 Cunxian Song1 1Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Science and Peking Union Medical College, 2Institute of Polymer Chemistry, Nankai University, 3Center for Medical Device Evaluation of Tianjin, Tianjin, People's Republic of China  *These authors contributed equally to this work Background: Star-shaped polymers provide more terminal groups, and are promising for application in drug-delivery systems. Methods: A new series of six-arm star-shaped poly(lactic-co-glycolic acid (6-s-PLGA was synthesized by ring-opening polymerization. The structure and properties of the 6-s-PLGA were characterized by carbon-13 nuclear magnetic resonance spectroscopy, infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry. Then, paclitaxel-loaded six-arm star-shaped poly(lactic-co-glycolic acid nanoparticles (6-s-PLGA-PTX-NPs were prepared under the conditions optimized by the orthogonal testing. High-performance liquid chromatography was used to analyze the nanoparticles' encapsulation efficiency and drug-loading capacity, dynamic light scattering was used to determine their size and size distribution, and transmission electron microscopy was used to evaluate their morphology. The release performance of the 6-s-PLGA-PTX-NPs in vitro and the cytostatic effect of 6-s-PLGA-PTX-NPs were investigated in comparison with paclitaxel-loaded linear poly(lactic-co-glycolic acid nanoparticles (L-PLGA-PTX-NPs. Results: The results of carbon-13 nuclear magnetic resonance spectroscopy and infrared spectroscopy suggest that the polymerization was successfully initiated by inositol and confirm the structure of 6-s-PLGA. The molecular weights of a series of 6-s-PLGAs had a ratio corresponding to the molar ratio of raw materials to initiator

  7. Synthesis and crystal structures of new complexes of Np(V) glycolate with 2,2'-bipyridine, [NpO2(C10H8N2)(OOC2H2OH)].1.5H2O and [NpO2(C10H8N2)(OOC2H2OH)].2.5H2O

    Single crystals were prepared, and the structures of two complexes of Np(V) glycolate with 2,2'-bipyridine of the compositions [NpO2(C10H8N2)(OOC2H2OH)].1.5H2O (I) and [NpO2(C10H8N2)(OOC2H2OH)]2.5H2O (II) were studied. The structures of the compounds are based on neptunyl-glycolate chains in which the glycolate anion manifests its complexation ability in different manner. In structure I, the bidentate-bridging anion links the adjacent NpO2- cations through the oxygen atoms of the carboxylate group. The neptunyl-glycolate chains of I exhibits the mutual coordination of the NpO2- cations acting toward each other simultaneously as ligands and coordinating centers. In compound II, the glycolate anion is bidentately coordinated to one neptunium atom to form a planar five-membered metallocycle [NpOCCO]. The O atom external with respect to the metallocycle is in the coordination environment of the adjacent neptunyl. The nitrogen-containing molecular ligand Bipy is included into the coordination environment of Np. The coordination polyhedron of the Np atoms in both structures is a pentagonal bipyramid in which the average Np-N bond length is 2.666 Aa (I) and 2.596 Aa (II). (orig.)

  8. Characterizations of Cuprous Oxide Thin Films Prepared by Sol-Gel Spin Coating Technique with Different Additives for the Photoelectrochemical Solar Cell

    D. S. C. Halin

    2014-01-01

    Full Text Available Cuprous oxide (Cu2O thin films were deposited onto indium tin oxide (ITO coated glass substrate by sol-gel spin coating technique using different additives, namely, polyethylene glycol and ethylene glycol. It was found that the organic additives added had a significant influence on the formation of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD, field emission scanning electron microscopy (FESEM, and ultraviolet-visible spectroscopy (UV-Vis. Based on the FESEM micrographs, the grain size of film prepared using polyethylene glycol additive has smaller grains of about 83 nm with irregular shapes. The highest optical absorbance film was obtained by the addition of polyethylene glycol. The Cu2O thin films were used as a working electrode in the application of photoelectrochemical solar cell (PESC.

  9. Preparation of poly (alkylcyanoacrylate) nanoparticles by polymerization of water-free microemulsions

    Krauel, Karen; Graf, Anja; Hook, Sarah M;

    2006-01-01

    designated as droplet, bicontinuous or solution type microemulsions using conductivity, viscosity and self-diffusion NMR. Nanoparticles were prepared by polymerization of selected microemulsions with ethyl-2-cyanoacrylate and the morphology of the particles was investigated. Addition of monomer to all types...... considering that polymerization is expected to occur at a water-oil interface by base-catalysed polymerization. It would appear that propylene glycol is sufficiently nucleophilic to initiate the polymerization. The use of water-free microemulsions as templates for the preparation of poly (alkylcyanoacrylate......Phase diagrams of the pseudoternary systems ethyloleate, polyoxyethylene 20 sorbitan mono-oleate/sorbitan monolaurate and propylene glycol with and without butanol as a co-surfactant were prepared. Areas containing optically isotropic, one-phase systems were identified and samples therein...

  10. Radioprotective preparation

    The invention is intended for radiation injuries prophylaxis in mammals. It has an well expressed radioprotective effect against acute gamma irradiation on cellular level as well as a prolonged action when applied up to 48 hours before the acute irradiation. The preparation is a coprecipitate of the natural tripeptide glutathione (reduced form) and polyvinyl pyrrolidone (pvp) in ratio 30-60/70-40. It is obtained by incubation method with subsequent lyophilization from water solution of the initial components. The molecular mass of the pvp is 20 till 360.103. 2 claims

  11. Analyzing solubility of acid gas and light alkanes in triethylene glycol

    Alireza Bahadori; Had B.Vuthaluru; Saeid Mokhatab

    2008-01-01

    Physical solvents such as ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) are commonly used in wet gas dehydration processes with TEG being the most popular due to ease of regeneration and low solvent losses. Unfortunately, TEG absorbs significantly more hydrocarbons and acid gases than EG or DEG. Quantifying this amount of absorption is therefore critical in order to minimize hydrocarbon losses or to optimize hydrocarbon recovery depending on the objective of the process. In this article, a new correlation that fully covers the operating ranges of TEG dehydration units is developed in order to determine the solubility of light alkanes and acid gases in TEG solvent. The influence of several parameters on hydrocarbon and acid gas solubility including temperature, pressure, and solvent content is also examined.

  12. Metabolism and disposition of dipropylene glycol monomethyl ether (DPGME) in male rats

    Male Fischer 344 rats were given a single oral dose of approximately 1289 mg/kg (8.7 mmol/kg) of [14C]DPGME. After dosing, expired air, excreta, and tissues were analyzed for 14C activity, and metabolites in urine were isolated and identified. Approximately 60% of the administered 14C activity was excreted in urine, while 27% was eliminated as 14CO2 within 48 hr after dosing. DPGME, PGME, dipropylene glycol, propylene glycol, as well as sulfate and glucuronide conjugates of DPGME were identified in urine of animals given [14C]DPGME. Results of the study indicate that DPGME is metabolized via the same routes to the same general types of metabolites as previously identified for propylene glycol monomethyl ether (PGME)

  13. DWPF nitric-glycolic flowsheet chemical process cell chemistry. Part 1

    Zamecnik, J. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-02-01

    The conversions of nitrite to nitrate, the destruction of glycolate, and the conversion of glycolate to formate and oxalate were modeled for the Nitric-Glycolic flowsheet using data from Chemical Process Cell (CPC) simulant runs conducted by SRNL from 2011 to 2015. The goal of this work was to develop empirical correlations for these variables versus measureable variables from the chemical process so that these quantities could be predicted a-priori from the sludge composition and measurable processing variables. The need for these predictions arises from the need to predict the REDuction/OXidation (REDOX) state of the glass from the Defense Waste Processing Facility (DWPF) melter. This report summarizes the initial work on these correlations based on the aforementioned data. Further refinement of the models as additional data is collected is recommended.

  14. Direct conversion of cellulose to glycolic acid with a phosphomolybdic acid catalyst in a water medium

    Zhang, Jizhe

    2012-08-03

    Direct conversion of cellulose to fine chemicals has rarely been achieved. We describe here an eco-benign route for directly converting various cellulose-based biomasses to glycolic acid in a water medium and oxygen atmosphere in which heteromolybdic acids act as multifunctional catalysts to catalyze the hydrolysis of cellulose, the fragmentation of monosaccharides, and the selective oxidation of fragmentation products. With commercial α-cellulose powder as the substrate, the yield of glycolic acid reaches 49.3%. This catalytic system is also effective with raw cellulosic biomass, such as bagasse or hay, as the starting materials, giving rise to remarkable glycolic acid yields of ∼30%. Our heteropoly acid-based catalyst can be recovered in solid form after reaction by distilling out the products and solvent for reuse, and it exhibits consistently high performance in multiple reaction runs. © 2012 American Chemical Society.

  15. Laser processing of polyethylene glycol derivative and block copolymer thin films

    Cristescu, R. [National Institute for Laser, Plasma and Radiation Physics, MG-36, RO-77125, Bucharest (Romania)], E-mail: rodica.cristescu@inflpr.ro; Popescu, C.; Popescu, A.C.; Grigorescu, S.; Duta, L.; Mihailescu, I.N. [National Institute for Laser, Plasma and Radiation Physics, MG-36, RO-77125, Bucharest (Romania); Andronie, A.; Stamatin, I. [University of Bucharest, 3Nano-SAE Research Center, P.O. Box MG-11, Bucharest-Magurele (Romania); Ionescu, O.S.; Mihaiescu, D. [University of Agriculture Sciences and Veterinary Medicine, 59 Marasti, Bucharest (Romania); Buruiana, T. [Petru Poni Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda, 41A, Iasi (Romania); Chrisey, D.B. [Rensselaer Polytechnic Institute, Department of Material Science, 110 8th Street, Troy, NY 12180-3590 (United States)

    2009-03-01

    We report the deposition by MAPLE of: (i) a novel polyethylene glycol derivative with carboxyl functional groups and (ii) a block copolymer: poly(ethylene glycol)methyl ether-block-poly(caprolactone)-block-poly(ethylene glycol)methyl ether. We used a KrF* excimer laser source ({lambda} = 248 nm, {tau} = 25 ns, {nu} = 5 Hz). The laser fluence was set within the 200-700 mJ/cm{sup 2} range. The deposited thin films have been investigated by FTIR and AFM. We have concluded that the main functional groups of starting materials are present in the transferred film. We also examined the influence of laser fluence on both thin film structure and morphology.

  16. A DNA glycosylase from human lymphoblasts that releases cis-thymine glycol from oxidized DNA

    An endonuclease (termed the UVX endonuclease) partially purified from cultured human leukemic lymphoblasts (CEM-CCRF line) was previously shown to act specifically on DNA irradiated by ionizing radiation, UV light, or treated with osmium tetroxide. This activity is tightly associated with an endonuclease specific for apurinic /apyrimidinic (AP) sites in DNA, suggesting that the initial attack on the radiation or oxidation induced lesions is by a DNA glycosylase that generates such AP sites. Thymine glycol has been shown to be a product common to γ-irradiated and oxidized DNA and in the present studies the authors have shown that the UVX endonuclease releases free cis-thymine glycol from osmium tetroxide treated DNA. HPLC analysis of the reaction products failed to detect any cis-thymidine glycol or nucleotide material indicating that the activity responsible is truly a DNA glycosylase. This enzyme thus resembles Endonuclease III of E. coli which contains both AP endonuclease and thymine glucol-DNA glycosylase activities

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

    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.

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

    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.

  19. Comparative study of 15% TCA peel versus 35% glycolic acid peel for the treatment of melasma

    Neerja Puri

    2012-01-01

    Full Text Available Background: Chemical peels are the mainstay of a cosmetic practitioner′s armamentarium because they can be used to treat some skin disorders and can provide aesthetic benefit. Objectives: To compare 15% TCA peel and 35% glycolic acid peel for the treatment of melasma. Material and Methods: We selected 30 participants of melasma aged between 20 and 50 years from the dermatology outpatient department and treated equal numbers with 15% TCA and 35% glycolic acid. Results: Subjective response as graded by the patient showed good or very good response in 70% participants in the glycolic acid group and 64% in the TCA group. Conclusions: There was statistically insignificant difference in the efficacy between the two groups for the treatment of melasma.

  20. Laser processing of polyethylene glycol derivative and block copolymer thin films

    We report the deposition by MAPLE of: (i) a novel polyethylene glycol derivative with carboxyl functional groups and (ii) a block copolymer: poly(ethylene glycol)methyl ether-block-poly(caprolactone)-block-poly(ethylene glycol)methyl ether. We used a KrF* excimer laser source (λ = 248 nm, τ = 25 ns, ν = 5 Hz). The laser fluence was set within the 200-700 mJ/cm2 range. The deposited thin films have been investigated by FTIR and AFM. We have concluded that the main functional groups of starting materials are present in the transferred film. We also examined the influence of laser fluence on both thin film structure and morphology

  1. Effects of ethylene glycol ethers on diesel fuel properties and emissions in a diesel engine

    Gomez-Cuenca, F.; Gomez-Marin, M. [Compania Logistica de Hidrocarburos (CLH), Central Laboratory, Mendez Alvaro 44, 28045 Madrid (Spain); Folgueras-Diaz, M.B., E-mail: belenfd@uniovi.es [Department of Energy, University of Oviedo, Independencia 13, 33004 Oviedo (Spain)

    2011-08-15

    Highlights: {yields} Effect of ethylene glycol ethers on diesel fuel properties. {yields} Effect of ethylene glycol ethers on diesel engine specific consumption and emissions. {yields} Blends with {<=}4 wt.% of oxygen do not change substantially diesel fuel quality. {yields} Blends with 1 and 2.5 wt.% of oxygen reduce CO and HC emissions, but not smoke. - Abstract: The effect of ethylene glycol ethers on both the diesel fuel characteristics and the exhaust emissions (CO, NO{sub x}, smoke and hydrocarbons) from a diesel engine was studied. The ethers used were monoethylene glycol ethyl ether (EGEE), monoethylene glycol butyl ether (EGBE), diethylene glycol ethyl ether (DEGEE). The above effect was studied in two forms: first by determining the modification of base diesel fuel properties by using blends with oxygen concentration around 4 wt.%, and second by determining the emission reductions for blends with low oxygen content (1 wt.%) and with 2.5 wt.% of oxygen content. The addition of DEGEE enhances base diesel fuel cetane number, but EGEE and EGBE decrease it. For concentrations of {>=}4 wt.% of oxygen, EGEE and diesel fuel can show immiscibility problems at low temperatures ({<=}0 {sup o}C). Also, every oxygenated compound, according to its boiling point, modifies the distillation curve at low temperatures and the distillate percentage increases. These compounds have a positive effect on diesel fuel lubricity, and slightly decrease its viscosity. Blends with 1 and 2.5 wt.% oxygen concentrations were used in order to determine their influence on emissions at both full and medium loads and different engine speeds. Generally, all compounds help to reduce CO, and hydrocarbon emissions, but not smoke. The best results were obtained for blends with 2.5 wt.% of oxygen. At this concentration, the additive efficiency in decreasing order was EGEE > DEGEE > EGBE for CO emissions and DGEE > EGEE > EGBE for hydrocarbon emissions. For NO{sub x}, both its behaviour and the

  2. Effects of ethylene glycol ethers on diesel fuel properties and emissions in a diesel engine

    Highlights: → Effect of ethylene glycol ethers on diesel fuel properties. → Effect of ethylene glycol ethers on diesel engine specific consumption and emissions. → Blends with ≤4 wt.% of oxygen do not change substantially diesel fuel quality. → Blends with 1 and 2.5 wt.% of oxygen reduce CO and HC emissions, but not smoke. - Abstract: The effect of ethylene glycol ethers on both the diesel fuel characteristics and the exhaust emissions (CO, NOx, smoke and hydrocarbons) from a diesel engine was studied. The ethers used were monoethylene glycol ethyl ether (EGEE), monoethylene glycol butyl ether (EGBE), diethylene glycol ethyl ether (DEGEE). The above effect was studied in two forms: first by determining the modification of base diesel fuel properties by using blends with oxygen concentration around 4 wt.%, and second by determining the emission reductions for blends with low oxygen content (1 wt.%) and with 2.5 wt.% of oxygen content. The addition of DEGEE enhances base diesel fuel cetane number, but EGEE and EGBE decrease it. For concentrations of ≥4 wt.% of oxygen, EGEE and diesel fuel can show immiscibility problems at low temperatures (≤0 oC). Also, every oxygenated compound, according to its boiling point, modifies the distillation curve at low temperatures and the distillate percentage increases. These compounds have a positive effect on diesel fuel lubricity, and slightly decrease its viscosity. Blends with 1 and 2.5 wt.% oxygen concentrations were used in order to determine their influence on emissions at both full and medium loads and different engine speeds. Generally, all compounds help to reduce CO, and hydrocarbon emissions, but not smoke. The best results were obtained for blends with 2.5 wt.% of oxygen. At this concentration, the additive efficiency in decreasing order was EGEE > DEGEE > EGBE for CO emissions and DGEE > EGEE > EGBE for hydrocarbon emissions. For NOx, both its behaviour and the sequence are opposite to that of CO.

  3. Effects of reaction conditions on the grafting percentage of poly(ethylene glycol)-block-poly(?-benzyl L-glutamate)-graft-poly(ethylene glycol) copolymer

    In the present work, poly(ethylene glycol)-block-poly(?-benzyl L-glutamate)-graft-poly(ethylene glycol) (PEG-b-PBLG-g-PEG) copolymer was synthesized by the ester exchange reaction of PEG-block-PBLG copolymer with PEG chain. Structure and properties of PEG-b-PBLG-g-PEG copolymer were investigated by fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and differential scanning calorimeter (DSC). The effects of reaction temperature, reaction time, and the chain length of PBLG segments on the grafting percentage of PEG-b-PBLG-g-PEG copolymer were studied. Experimental results demonstrated that the grafting percentage of PEG-b-PBLG-g-PEG copolymer increased with the increase of both reaction temperature and reaction time, while the increase of the chain length of PBLG segments in block copolymer decreased the grafting percentage. (author)

  4. A rapid analysis of plasma/serum ethylene and propylene glycol by headspace gas chromatography

    Ehlers, Alexandra; Morris, Cory; Krasowski, Matthew D

    2013-01-01

    A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using 1,3-propanediol as the internal standard. The method employed a single-step derivitization using phenylboronic acid, was linear to 200 mg/dL and had a lower limit of quantitation of 1 mg/dL suitable for clinical analyses. The analytical method described allows for laboratories with HS-GC instrumentation to analyze ethanol, methanol, iso...

  5. Self-assembled nanoparticles of glycol chitosan – Ergocalciferol succinate conjugate, for controlled release

    Quinones, Javier Perez; Gothelf, Kurt Vesterager; Kjems, Jørgen;

    2012-01-01

    Glycol chitosan was linked to vitamin D2 hemisuccinate (ergocalciferol hemisuccinate) for controlled release through water-soluble carbodiimide activation. The resulting conjugate formed self-assembled nanoparticles in aqueous solution with particle size of 279 nm and ergocalciferol hemisuccinate...... content of 8.4% (w/w). Almost spherical 50–90 nm nanoparticles were observed by scanning and transmission electron microscopy upon drying. Drug linking to glycol chitosan was confirmed by FTIR spectroscopy and proton NMR. Particles were also characterized by differential scanning calorimetry and wide...

  6. Extraction of cesium and barium by dicarbollide and polyethylene glycol in the presence of alkylammonium cations

    The extraction of cesium and barium cations into nitrobenzene and 60 % (vol.%) nitrobenzene + 40 % CCl4 mixture in the presence of dicarbollide (+Slovafol 909), and primary alkylammonium cations has been studied. Extraction constants determined for three methylammonium cations correlate well with their hydration enthalpies. Reverse order of the hydrophobicity of methylammonium cations (competition with bare Cs+ ion) and for their tendency to enter the polyethylene glycol complex (competition with polyethylene glycol complexed Cs+ and Ba2+ ions) is recorded. The possibility of the regeneration of the organic phase after stripping of Cs+ and Ba2+ ions with methylammonium cations has been investigated. (author) 18 refs.; 7 figs.; 3 tabs

  7. Mineral induced phosphorylation of glycolate ion--a metaphor in chemical evolution

    Kolb, V.; Zhang, S.; Xu, Y.; Arrhenius, G.

    1997-01-01

    Bilateral surface-active minerals with excess positive charge concentrate glycolate and trimetaphosphate ion from l0(-3) m aqueous solution to half-saturation of the internal surface sites, and induce phosphorylation of glycolate ion in the mineral with trimetaphosphate, sorbed from l0(-2) m solution. By utilizing reactants from dilute solution at near-neutral pH, and eliminating the need for participating organic nitrogen compounds, the reaction comprises several elements considered necessary for geochemical realism in models for molecular evolution.

  8. Microgels of polyaspartamide and poly(ethylene glycol) derivatives obtained by γ-irradiation

    The copolymer PHG based on α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) functionalized with glycidyl methacrylate has been exposed in aqueous solution to a γ-ray source at different irradiation doses (2, 2.5 and 3.5 kGy), alone or in combination with poly(ethylene glycol)dimethacrylate (PEGDMA) or poly(ethylene glycol)diacrylate (PEGDA). The irradiation produces microgel systems that have been characterized by viscosity measurements. Lyophilization of microgels gives rise to samples able to swell instantaneously in water whereas their treatment with acetone produces swellable microparticles that have been characterized

  9. Hydrolysis of Carbonyl Sulfide in Binary Mixture of Diethylene Glycol Diethyl Ether and Water

    李新学; 刘迎新; 魏雄辉

    2005-01-01

    The solubility and hydrolysis of carbonyl sulfide in binary mixture of diethylene glycol diethyl ether and water are studied as a function of composition. The use of an aqueous solution of diethylene glycol diethyl ether enhances the solubility and hydrolysis rate of carbonyl sulfide compared with that in pure water. The composition of the mixture with maximum hydrolysis rate varies with temperature. The thermophysical properties including density, viscosity, and surface tension as a function of composition at 20℃ under atmospheric pressure as well as liquid-liquid equilibrium (LLE) data over the temperature range from 28℃ to 90℃ are also measured for the binary mixture.

  10. Thermodynamic study of the solubility of triclocarban in ethanol + propylene glycol mixtures

    Andres R. Holguín

    2012-01-01

    Full Text Available By using the van't Hoff and Gibbs equations the apparent thermodynamic functions Gibbs energy, enthalpy, and entropy of solution for triclocarban in ethanol + propylene glycol mixtures were evaluated from solubility data determined at temperatures from (293.15 to 313.15 K. The drug solubility was greatest in the mixture with 0.60 in mass fraction of ethanol and lowest in neat propylene glycol at almost all the temperatures studied. Non-linear enthalpy-entropy compensation is found indicating apparently different mechanisms of the solution process according to the mixtures composition.

  11. Thermodynamic study of the solubility of triclocarban in ethanol + propylene glycol mixtures

    Andres R. Holguín; Daniel R. Delgado; Fleming Martínez

    2012-01-01

    By using the van't Hoff and Gibbs equations the apparent thermodynamic functions Gibbs energy, enthalpy, and entropy of solution for triclocarban in ethanol + propylene glycol mixtures were evaluated from solubility data determined at temperatures from (293.15 to 313.15) K. The drug solubility was greatest in the mixture with 0.60 in mass fraction of ethanol and lowest in neat propylene glycol at almost all the temperatures studied. Non-linear enthalpy-entropy compensation is found indicating...

  12. The characteristics of nano-sized Gd-doped CeO2 particles prepared by spray pyrolysis

    Gd-doped ceria particles with nanometer size were prepared by spray pyrolysis from spray solution containing ethylene glycol. The effect of ethylene glycol and gadolinium dopant on the morphology of the ceria particles prepared by spray pyrolysis was investigated. The Gd-doped ceria particles prepared from pure aqueous solution had submicron size, spherical shape and dense structure after post-treatment. The Gd-doped ceria particles prepared from solution containing ethylene glycol had loosely aggregated structure of the primary particles with nanometer size after post-treatment at 900 and 1050 deg. C. The Gd-doped ceria particles had more loosely aggregated and regular morphology than the pure ceria particles at the post-treatment temperature of 900 deg. C. The gadolinium component used as dopant suppressed grain growth in ceria particles prepared by spray pyrolysis. Nanometer size Gd-doped ceria particles were prepared by a ball milling process of the particles obtained by spray pyrolysis. The mean size of the Gd-doped ceria particles was 46 nm after a post-treatment at 1050 deg. C. The ionic conductivity of the Gd-doped ceria particles prepared by spray pyrolysis was compared with that of the commercial yttria-stabilized zirconia (YSZ)

  13. Application of solid-phase heterogeneous catalytic hydrogenation for preparation of ethanolamine labelled by tritium and ethanolamides of aroachidonic, eicosanepentaenic, docosahexaenic acids labelled by tritium partially

    Ethanolamine labelled with tritium with 35-40 Ci/mmol molar radioactivity is produced from glycolic acid nitrile by means of solid-phase heterogeneous catalytic hydrogenation on 5% Rh/C. Preparational quantities of labelled ethanolamine are produced with 10-20% yield with the use of 5% of pd?C and 70% of glycolic acid aqueous nitrile, the molar activity of the preparation required is 4-6 Ci/mmol. Ethanolamides of arachidonic, eicosapentaenoic, docosahexaenoic acids are synthesized from the labelled ethanolamine. The compound produced are tested by chromatographic and fermentative methods

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

    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 a...

  15. 76 FR 36349 - Diethylene Glycol MonoEthyl Ether (DEGEE); Exemption From the Requirement of a Tolerance

    2011-06-22

    ... AGENCY 40 CFR Part 180 Diethylene Glycol MonoEthyl Ether (DEGEE); Exemption From the Requirement of a... establishes an exemption from the requirement of a tolerance for residues of Diethylene Glycol MonoEthyl Ether...) 305-5805. II. Petition for Exemption In the Federal Register of July 9, 2008 (73 FR 39291)...

  16. Generation of acetyl free radicals by radiolysis: comparison of free radicals generated from acetaldehyde and ethylene-glycol

    The optical absorption spectra of the intermediates obtained by pulse radiolysis of N2O-saturated solutions of acetaldehyde or ethylene-glycol and the kinetics of their decays have been investigated. Results suggest that the OH· radical reactions with acetaldehyde or ethylene-glycol produce acetyl and formylmethyl radicals. Besides, these radicals are shown to reduce ferricytochrome c

  17. Bioactivity, physical and chemical properties of MTA mixed with propylene glycol

    Vaishali Prakash NATU

    2015-08-01

    Full Text Available AbstractObjective To investigate the physical (setting time, hardness, flowability, microstructure and chemical (pH change, calcium release, crystallinity properties and the biological outcomes (cell survival and differentiation of mineral trioxide aggregate (MTA mixed using different proportions of propylene glycol (PG and water.Material and Methods White MTA was mixed with different water/PG ratios (100/0, 80/20 and 50/50. Composition (XRD, microstructure (SEM, setting time (ASTM C266-13, flowability (ANSI/ADA 57-2000, Knoop hardness (100 g/10 s and chemical characteristics (pH change and Ca2+ release for 7 days were evaluated. Cell proliferation, osteo/odontoblastic gene expression and mineralization induced by MTA mixed with PG were evaluated. MTA discs (5 mm in diameter, 2 mm thick were prepared and soaked in culture medium for 7 days. Next, the discs were removed and the medium used to culture dental pulp stem cells (DPSC for 28 days. Cells survival was evaluated using MTS assay (24, 72 and 120 h and differentiation with RT-PCR (ALP, OCN, Runx2, DSPP and MEPE and alizarin red staining (7 and 14 days. Data were analysed using one-way ANOVA and Tukey’s post-hoc analysis (a=0.05.Results The addition of PG significantly increased setting time, flowability and Ca2+ release, but it compromised the hardness of the material. SEM showed that 50/50 group resulted porous material after setting due to the incomplete setting reaction, as shown by XRD analysis. The addition of PG (80/20 and 50/50 was not capable to improve cell proliferation or to enhance gene expression, and mineralized deposition of DPSC after 7 and 14 days as compared to the 100/0.Conclusion Except for flowability, the addition of PG did not promote further improvements on the chemical and physical properties evaluated, and it was not capable of enhancing the bioactivity of the MTA.

  18. Photocurable surgical tissue adhesive glues composed of photoreactive gelatin and poly(ethylene glycol) diacrylate.

    Nakayama, Y; Matsuda, T

    1999-01-01

    This article presents a novel photochemically driven surgical tissue adhesive technology using photoreactive gelatins and a water-soluble difunctional macromer (poly(ethylene glycol) diacrylate: PEGDA).The gelatins were partially derivatized with photoreactive groups, such as ultraviolet light (UV)-reactive benzophenone and visible light-reactive xanthene dye (e.g., fluorescein sodium salt, eosin Y, and rose bengal). A series of the prepared photocurable tissue adhesive glues, consisting of the photoreactive gelatin, PEGDA, and a saline solution with or without ascorbic acid as a reducing agent, were viscous solutions under warming, and their effectiveness was evaluated as hemostasis- and anastomosis-aid in cardiovascular surgery. Regardless of the type of photoreactive groups, the irradiation of the photocurable tissue adhesive glues by UV or visible light within 1 min produced water-swollen gels, which had a high adhesive strength to wet collagen film. These were due to the synergistic action of photoreactive group-initiated photo-cross-linking and photograft polymerization. An increase in the irradiation time resulted in increased gel yield and reduced water swellability. A decrease in the molecular weight of PEGDA and an increase in concentration of both gelatin and PEGDA resulted in reduced water swellability and increased tensile and burst strengths of the resultant gels. In rats whose livers were injured with a trephine in laparotomy, the bleeding spots were coated with the photocurable adhesive glue and irradiated through an optical fiber. The coated solution was immediately converted to a swollen gel. The gel was tightly adhered to the liver tissue presumably by interpenetration, and concomitantly hemostasis was completed. The anastomosis treatment with the photocurable glue in the canine abdominal or thoracic aortas incised with a knife resulted in little bleeding under pulsatile flow after declamping. Histological examination showed that the glues

  19. Metabolic fate of poly-(lactic-co-glycolic acid-based curcumin nanoparticles following oral administration

    Harigae T

    2016-06-01

    Full Text Available Takahiro Harigae,1 Kiyotaka Nakagawa,1 Taiki Miyazawa,2 Nao Inoue,3 Fumiko Kimura,1 Ikuo Ikeda,3 Teruo Miyazawa4,5 1Food and Biodynamic Chemistry Laboratory, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan; 2Vascular Biology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA; 3Laboratory of Food and Biomolecular Science, Graduate School of Agricultural Science, 4Food and Biotechnology Innovation Project, New Industry Creation Hatchery Center, 5Food and Health Science Research Unit, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan Purpose: Curcumin (CUR, the main polyphenol in turmeric, is poorly absorbed and rapidly metabolized following oral administration, which severely curtails its bioavailability. Poly-(lactic-co-glycolic acid-based CUR nanoparticles (CUR-NP have recently been suggested to improve CUR bioavailability, but this has not been fully verified. Specifically, no data are available about curcumin glucuronide (CURG, the major metabolite of CUR found in the plasma following oral administration of CUR-NP. Herein, we investigated the absorption and metabolism of CUR-NP and evaluated whether CUR-NP improves CUR bioavailability.Methods: Following oral administration of CUR-NP in rats, we analyzed the plasma and organ distribution of CUR and its metabolites using high-performance liquid chromatography-tandem mass spectrometry. To elucidate the mechanism of increased intestinal absorption of CUR-NP, we prepared mixed micelles comprised of phosphatidylcholine and bile salts and examined the micellar solubility of CUR-NP. Additionally, we investigated the cellular incorporation of the resultant micelles into differentiated Caco-2 human intestinal cells.Results: Following in vivo administration of CUR-NP, CUR was effectively absorbed and present mainly as CURG in the plasma which contained significant amounts of the metabolite compared with

  20. Metabolic fate of poly-(lactic-co-glycolic acid)-based curcumin nanoparticles following oral administration

    Harigae, Takahiro; Nakagawa, Kiyotaka; Miyazawa, Taiki; Inoue, Nao; Kimura, Fumiko; Ikeda, Ikuo; Miyazawa, Teruo

    2016-01-01

    Purpose Curcumin (CUR), the main polyphenol in turmeric, is poorly absorbed and rapidly metabolized following oral administration, which severely curtails its bioavailability. Poly-(lactic-co-glycolic acid)-based CUR nanoparticles (CUR-NP) have recently been suggested to improve CUR bioavailability, but this has not been fully verified. Specifically, no data are available about curcumin glucuronide (CURG), the major metabolite of CUR found in the plasma following oral administration of CUR-NP. Herein, we investigated the absorption and metabolism of CUR-NP and evaluated whether CUR-NP improves CUR bioavailability. Methods Following oral administration of CUR-NP in rats, we analyzed the plasma and organ distribution of CUR and its metabolites using high-performance liquid chromatography-tandem mass spectrometry. To elucidate the mechanism of increased intestinal absorption of CUR-NP, we prepared mixed micelles comprised of phosphatidylcholine and bile salts and examined the micellar solubility of CUR-NP. Additionally, we investigated the cellular incorporation of the resultant micelles into differentiated Caco-2 human intestinal cells. Results Following in vivo administration of CUR-NP, CUR was effectively absorbed and present mainly as CURG in the plasma which contained significant amounts of the metabolite compared with other organs. Thus, CUR-NP increased intestinal absorption of CUR rather than decreasing metabolic degradation and conversion to other metabolites. In vitro, CUR encapsulated in CUR-NP was solubilized in mixed micelles; however, whether the micelles contained CUR or CUR-NP had little influence on cellular uptake efficiency. Therefore, we suggest that the high solubilization capacity of CUR-NP in mixed micelles, rather than cellular uptake efficiency, explains the high intestinal absorption of CUR-NP in vivo. Conclusion These findings provide a better understanding of the bioavailability of CUR and CUR-NP following oral administration. To improve