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Sample records for aqueous polyethylene glycol

  1. Water potential of aqueous polyethylene glycol.

    Science.gov (United States)

    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

  2. Polyethylene Glycol as Support and Phase Transfer Catalyst in Aqueous Palladium-catalyzed Liquid-phase Synthesis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Excellent yields and purity were obtained in the aqueous medium Suzuki, Sonogashira, Stille and Heck reactions using palladium (Ⅱ) as catalyst in liquid phase synthesis. Polyethylene glycol (PEG) acted as soluble polymeric support and phase transfer catalyst as well.

  3. Protein partitioning in poly(ethylene glycol)/sodium polyacrylate aqueous two-phase systems.

    Science.gov (United States)

    Johansson, Hans-Olof; Magaldi, Flavio Musa; Feitosa, Eloi; Pessoa, Adalberto

    2008-01-18

    The partition of hemoglobin, lysozyme and glucose-6-phosphate dehydrogenase (G6PDH) in a novel inexpensive aqueous two-phase system (ATPS) composed by poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA) has been studied. The effect of NaCl and Na(2)SO(4), pH and PEG molecular size on the partitioning has been studied. At high pH (above 9), hemoglobin partitions strongly to the PEG-phase. Although some precipitation of hemoglobin occurs, high recovery values are obtained particularly for lysozyme and G6PDH. The partitioning forces are dominated by the hydrophobic and electrochemical (salt) effects, since the positively charged lysozyme and negatively charged G6PDH partitions to the non-charged PEG and the strongly negatively charged polyacrylate enriched phase, respectively. PMID:18078945

  4. Formation of globules and aggregates of DNA chains in DNA/polyethylene glycol/monovalent salt aqueous solutions

    OpenAIRE

    Kawakita, H.; Uneyama, T.; Kojima, M; Morishima, K.; Masubuchi, Y.; Watanabe, H.(Max-Planck-Institut für Kernphysik, 69117, Heidelberg, Germany)

    2009-01-01

    It has been known that giant DNA shows structural transitions in aqueous solutions under the existence of counterions and other polymers. However, the mechanism of these transitions has not been fully understood. In this study, we directly observed structures of probed (dye-labeled), dilute DNA chains in unprobed DNA/polyethylene glycol (PEG)/monovalent salt (NaCl) aqueous solutions with fluorescent microscopy to examine this mechanism. Specifically, we varied the PEG molecular weight and sal...

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

    Science.gov (United States)

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

    2015-10-01

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

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

    Science.gov (United States)

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

    2016-04-22

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

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

    Science.gov (United States)

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

    2016-04-22

    Partition behavior of adenosine and guanine mononucleotides was examined in aqueous dextran-polyethylene glycol (PEG) and PEG-sodium sulfate two-phase systems. The partition coefficients for each series of mononucleotides were analyzed as a functions of the number of phosphate groups and found to be dependent on the nature of nucleic base and on the type of ATPS utilized. It was concluded that an average contribution of a phosphate group into logarithm of partition coefficient of a mononucleotide cannot be used to estimate the difference between the electrostatic properties of the coexisting phases of ATPS. The data obtained in this study were considered together with those for other organic compounds and proteins reported previously, and the linear interrelationship between logarithms of partition coefficients in dextran-PEG, PEG-Na2SO4 and PEG-Na2SO4-0.215M NaCl (all in 0.01M Na- or K/Na-phosphate buffer, pH 7.4 or 6.8) was established. Similar relationship was found for the previously reported data for proteins in Dex-PEG, PEG-600-Na2SO4, and PEG-8000-Na2SO4 ATPS. It is suggested that the linear relationships of the kind established in ATPS may be observed for biological properties of compounds as well. PMID:27016118

  8. Two-step recrystallization of water in concentrated aqueous solution of poly(ethylene glycol).

    Science.gov (United States)

    Gemmei-Ide, Makoto; Motonaga, Tetsuya; Kasai, Ryosuke; Kitano, Hiromi

    2013-02-21

    Crystallization behavior of water in a concentrated aqueous solution of poly(ethylene glycol) (PEG) with a water content of 37.5 wt % was investigated by temperature variable mid-infrared (mid-IR) spectroscopy in a temperature range of 298-170 K. The mid-IR spectrum of water at 298 K showed that a large water cluster was not formed and that most of the water molecules were associated with the PEG chain. Ice formation, however, occurred as found in previous studies by differential scanning calorimetory. Ice formations were grouped into three types: crystallization at 231 K during cooling, that at 198 K during heating, and that at 210 K during heating. The latter two were just recrystallization. These ice formations were the direct transition from hydration species to ice without condensation regardless of crystallization or recrystallization. This means that the recrystallized water in the present system was not generated from low-density amorphous solid water. At a low cooling rate, nearly complete crystallization at 231 K during cooling and no recrystallization were observed. At a high cooling rate, no crystallization and two-step recrystallization at 198 and 210 K were observed. The former and latter recrystallizations were found to be generated from water associated with the PEG chains with ttg (the sequence -O-CH(2)-CH(2)-O- having a trans (t) conformation about the -C-O- bond and a gauche (g) conformation about the -C-C- bond) and random conformations, respectively. These results indicate that recrystallizable water does not have a single specific water structure.

  9. Thermodynamic modelling of phase equilibrium for water + poly(Ethylene glycol + salt aqueous two-phase systems

    Directory of Open Access Journals (Sweden)

    R.A.G. Sé

    2002-04-01

    Full Text Available The NRTL (nonrandom, two-liquid model, expressed in mass fraction instead of mole fraction, was used to correlate liquid-liquid equilibria for aqueous two-phase polymer-salt solutions. New interaction energy parameters for this model were determined using reported data on the water + poly(ethylene glycol + salt systems, with different molecular masses for PEG and the salts potassium phosphate, sodium sulfate, sodium carbonate and magnesium sulfate. The correlation of liquid-liquid equilibrium is quite satisfactory.

  10. Phase Diagrams of the Aqueous Two-Phase Systems of Poly(ethylene glycol)/Sodium Polyacrylate/Salts

    OpenAIRE

    Adalberto Pessoa Junior; Hans-Olof Johansson; Eloi Feitosa

    2011-01-01

    Aqueous two-phase systems consisting of polyethylene glycol (PEG), sodium polyacrylate (NaPAA), and a salt have been studied. The effects of the polymer size, salt type (NaCl, Na2SO4, sodium adipate and sodium azelate) and salt concentrations on the position of the binodal curve were investigated. The investigated PEG molecules had a molar mass of 2,000 to 8,000 g/mol, while that of NaPAA was 8,000 g/mol. Experimental phase diagrams, and tie lines and calculated phase diagrams, based on Flory...

  11. Phase Diagrams of the Aqueous Two-Phase Systems of Poly(ethylene glycol/Sodium Polyacrylate/Salts

    Directory of Open Access Journals (Sweden)

    Adalberto Pessoa Junior

    2011-03-01

    Full Text Available Aqueous two-phase systems consisting of polyethylene glycol (PEG, sodium polyacrylate (NaPAA, and a salt have been studied. The effects of the polymer size, salt type (NaCl, Na2SO4, sodium adipate and sodium azelate and salt concentrations on the position of the binodal curve were investigated. The investigated PEG molecules had a molar mass of 2,000 to 8,000 g/mol, while that of NaPAA was 8,000 g/mol. Experimental phase diagrams, and tie lines and calculated phase diagrams, based on Flory-Huggins theory of polymer solutions are presented. Due to strong enthalpic and entropic balancing forces, the hydrophobicity of the added salt has a strong influence on the position of the binodal, which could be reproduced by model calculations.

  12. Thermal properties and physicochemical behavior in aqueous solution of pyrene-labeled poly(ethylene glycol-polylactide conjugate

    Directory of Open Access Journals (Sweden)

    Chen WL

    2015-04-01

    Full Text Available Wei-Lin Chen,1,2 Yun-Fen Peng,1,3 Sheng-Kuo Chiang,1 Ming-Hsi Huang1–3 1National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan; 2Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan; 3PhD Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, Taichung, Taiwan Abstract: A fluorescence-labeled bioresorbable polymer was prepared by a coupling reaction of poly(ethylene glycol-polylactide (PEG-PLA with carboxyl pyrene, using N,N’-diisopropylcarbodiimide/1-hydroxy-7-azabenzotriazole (DIC/HOAt as a coupling agent and 4-dimethylaminopyridine (DMAP as a catalyst. The obtained copolymer, termed PEG-PLA-pyrene, was characterized using various analytical techniques, such as gel permeation chromatography (GPC, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS, proton nuclear magnetic resonance (1H-NMR, infrared spectroscopy (IR, differential scanning calorimetry (DSC, and thermogravimetric analysis (TGA, to identify the molecular structure and to monitor the thermal property changes before and after the reaction. The presence of a pyrene moiety at the end of polylactide (PLA did not alter the crystallization ability of the poly(ethylene glycol (PEG blocks, indicating that the conjugate preserved the inherent thermal properties of PEG-PLA. However, the presence of PEG-PLA blocks strongly reduced the melting of pyrene, indicating that the thermal characteristics were sensitive to PEG-PLA incorporation. Regarding the physicochemical behavior in aqueous solution, a higher concentration of PEG-PLA-pyrene resulted in a higher ultraviolet-visible (UV-vis absorbance and fluorescence emission intensity. This is of great interest for the use of this conjugate as a fluorescence probe to study the in vivo distribution as well as the internalization and intracellular localization of polymeric micelles

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  14. Salt effect on the (polyethylene glycol 8000 + sodium sulfate) aqueous two-phase system: Relative hydrophobicity of the equilibrium phases

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Luisa A., E-mail: laferreira@deb.uminho.pt [IBB - Institute for Biotechnology and Bioengineering, Centre for Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Teixeira, Jose A. [IBB - Institute for Biotechnology and Bioengineering, Centre for Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2011-08-15

    Highlights: > Gibbs free energy of transfer of a methylene group on PEG 8000 - Na{sub 2}SO{sub 4} ATPS. > Influence of salt additive on the hydrophobic character of the coexisting phases. > Partitioning behavior of a series of five sodium salts of DNP-amino acids. > A relationship between {Delta}G(CH{sub 2}), TLL and I of the salt additive was established. - Abstract: The relative hydrophobicity of the phases of several {l_brace}polyethylene glycol (PEG) 8000 + sodium sulfate (Na{sub 2}SO{sub 4}){r_brace} aqueous two-phase systems (ATPSs), all containing 0.01 mol . L{sup -1} sodium phosphate buffer (NaPB, pH 7.4) and increasing concentration of a salt additive, NaCl or KCl, up to 1.0 mol . L{sup -1}, was measured by the free energy of transfer of a methylene group between the phases, {Delta}G(CH{sub 2}). The {Delta}G(CH{sub 2}) of the systems was determined by partitioning of a homologous series of five sodium salts of dinitrophenylated (DNP) - amino acids with aliphatic side chains in three different tie-lines of each biphasic system. The relative hydrophobicity of the phases ranged from -0.125 to -0.183 kcal . mol{sup -1}, being the NaCl salt the one to provide the more effective changes. The results show that, within each system, there is a linear relationship between the {Delta}G(CH{sub 2}) and the tie-line length (TLL), and biphasic systems with high salt additive concentration present the most negative {Delta}G(CH{sub 2}) values. Therefore, the feasibility of establishing a relationship between the relative hydrophobicity of the phases in a given TLL and the ionic strength of the salt additive was investigated and a satisfactory correlation was found for each salt.

  15. Pectinases partitioning in aqueous two-phase systems: an integration of the systems poly(ethylene glycol/crude dextran and poly(ethylene glycol/ammonium sulphate

    Directory of Open Access Journals (Sweden)

    STANA N. PEJIN

    2004-04-01

    Full Text Available The partitioning of pectinases in the poly(ethylene glucol4000/ammonium sulpohate system was studied and also its application for enzymes extraction from the top phase of the poly(ethylene glucol4000/crude dextran system. Almost complete one-sided partition of endo-pectinase and exo-pectinase to the bottom phase of the polymer/salt system was achieved at a tie-line length of 37.16 %. The concentration factors were 1.73 and 3.25, respectively. The highest total endo- and exo-pectinase yields (72.41 % and 69.46 %, respectively were obtained by integration of the polymer/polymer system at a tie-line of 8.61 % and a high phase volume ratio and the polymer/salt system at a tie-line of 30.23 % and a low phase volume ratio. Integration of the partitioning at a high tie-line length in the polymer/polimer and a low tie-line length in the polymer/salt system resulted in a total concentration factor of 1.5 and a purification of 1.66 fold for exo-pectinase. The addition of phosphate to this integrated system improved the total concentration factor and purification fold of the activity to 1.73 and 2.14, respectively.

  16. Theoretical and experimental studies on freezing point depression and vapor pressure deficit as methods to measure osmotic pressure of aqueous polyethylene glycol and bovine serum albumin solutions.

    Science.gov (United States)

    Kiyosawa, Keitaro

    2003-05-01

    For survival in adverse environments where there is drought, high salt concentration or low temperature, some plants seem to be able to synthesize biochemical compounds, including proteins, in response to changes in water activity or osmotic pressure. Measurement of the water activity or osmotic pressure of simple aqueous solutions has been based on freezing point depression or vapor pressure deficit. Measurement of the osmotic pressure of plants under water stress has been mainly based on vapor pressure deficit. However, differences have been noted for osmotic pressure values of aqueous polyethylene glycol (PEG) solutions measured by freezing point depression and vapor pressure deficit. For this paper, the physicochemical basis of freezing point depression and vapor pressure deficit were first examined theoretically and then, the osmotic pressure of aqueous ethylene glycol and of PEG solutions were measured by both freezing point depression and vapor pressure deficit in comparison with other aqueous solutions such as NaCl, KCl, CaCl(2), glucose, sucrose, raffinose, and bovine serum albumin (BSA) solutions. The results showed that: (1) freezing point depression and vapor pressure deficit share theoretically the same physicochemical basis; (2) theoretically, they are proportional to the molal concentration of the aqueous solutions to be measured; (3) in practice, the osmotic pressure levels of aqueous NaCl, KCl, CaCl(2), glucose, sucrose, and raffinose solutions increase in proportion to their molal concentrations and there is little inconsistency between those measured by freezing point depression and vapor pressure deficit; (4) the osmotic pressure levels of aqueous ethylene glycol and PEG solutions measured by freezing point depression differed from the values measured by vapor pressure deficit; (5) the osmotic pressure of aqueous BSA solution measured by freezing point depression differed slightly from that measured by vapor pressure deficit.

  17. Prediction of liquid-liquid equilibria for polyethylene glycol based aqueous two-phase system by ASOG and UNIFAC method

    Directory of Open Access Journals (Sweden)

    M. Perumalsamy

    2009-03-01

    Full Text Available Liquid-Liquid equilibrium data were obtained for the polyethylene glycol2000(PEG2000-sodium citrate-water system at 298.15, 308.15 and 318.15 K. The effect of temperature on binodal and tie line data was studied and published in a previous article (Murugesan and Perumalsamy, 2005. The interaction parameters of ASOG and UNIFAC models were estimated using the LLE data of PEG2000-sodium citrate-water system and are used to predict the LLE data for PEG6000-sodium citrate-water system at 298.15, 308.15 and 318.15 K (literature data. The predicted LLE data by both ASOG and UNIFAC models showed good agreement with the experimental and literature data.

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

    Science.gov (United States)

    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.

  19. Aqueous polyethylene oxide solutions

    International Nuclear Information System (INIS)

    A number of aspects concerning the reorientation of polymer, water and ion hydration complexes have been studied in aqueous solution of polyethylene oxide (PEO). The polymer dynamics are investigated by 1H-PEO and 13C-PEO nuclear relaxation experiments. 162 refs.; 30 figs.; 19 tabs

  20. Statistical analysis of the effects of polyethylene glycol concentration and molecular weight on the sedimentation and resuspendability behavior of model aqueous dispersions.

    Science.gov (United States)

    Zhu, Wuxin; Vermeir, Lien; Govoreanu, Ruxandra; Verbruggen, Katrien; Ariën, Tina; Van der Meeren, Paul

    2013-09-10

    This work investigates the flocculation effect of polyethylene glycol (PEG) on typical aqueous dispersions, such as O/W emulsions and solid/liquid suspensions. Hereby, sunflower oil and flubendazole were selected as model ingredients, whereas microfluidization at variable driving air pressure was used to enable particle size distribution variations for both systems. The molecular weight of PEG varied from 2000 to 12,000g/mol while its concentration ranged from 50 to 100mg/ml. Statistical analysis revealed that both PEG concentration and molecular weight showed a flocculation enhancing effect. Hereby the inhibiting effect of particle size toward the formation of voluminous and easily resuspendable sediment could at least partially be overcome by selecting appropriate PEG characteristics.

  1. Optimization of Serine Protease Purification from Mango (Mangifera indica cv. Chokanan Peel in Polyethylene Glycol/Dextran Aqueous Two Phase System

    Directory of Open Access Journals (Sweden)

    Abdul Manap Mohd Yazid

    2012-03-01

    Full Text Available Mango peel is a good source of protease but remains an industrial waste. This study focuses on the optimization of polyethylene glycol (PEG/dextran-based aqueous two-phase system (ATPS to purify serine protease from mango peel. The activity of serine protease in different phase systems was studied and then the possible relationship between the purification variables, namely polyethylene glycol molecular weight (PEG, 4000–12,000 g·mol−1, tie line length (−3.42–35.27%, NaCl (−2.5–11.5% and pH (4.5–10.5 on the enzymatic properties of purified enzyme was investigated. The most significant effect of PEG was on the efficiency of serine protease purification. Also, there was a significant increase in the partition coefficient with the addition of 4.5% of NaCl to the system. This could be due to the high hydrophobicity of serine protease compared to protein contaminates. The optimum conditions to achieve high partition coefficient (84.2 purification factor (14.37 and yield (97.3% of serine protease were obtained in the presence of 8000 g·mol−1 of PEG, 17.2% of tie line length and 4.5% of NaCl at pH 7.5. The enzymatic properties of purified serine protease using PEG/dextran ATPS showed that the enzyme could be purified at a high purification factor and yield with easy scale-up and fast processing.

  2. Partition of proteins in aqueous two-phase systems based on Cashew-nut tree gum and poly(ethylene glycol

    Directory of Open Access Journals (Sweden)

    Leonie Asfora Sarubbo

    2004-09-01

    Full Text Available The partitioning of two proteins, bovine serum albumin (BSA and trypsin was studied in an aqueous poly(ethylene glycol(PEG- Cashew-nut tree gum system. The phase diagram was provided for Cashew-nut tree gum and PEG molecular weight of 1500 at two different temperatures. The influence of several parameters including concentrations of polymers, pH, salt addition and temperature on the partitioning of these proteins were investigated.. The results of this research demonstrated the importance of the protein characteristics for partitioning in aqueous biphasic system.A partição de duas proteínas, albumina de soro bovino (BSA e tripsina foi estudada no sistema bifásico aquoso Polietileno glicol(PEG - Goma do cajueiro. O diagrama de fases foi estabelecido para a Goma do Cajueiro e para PEG de peso molecular 1500 em duas diferentes temperaturas. A influência de vários parâmetros na partição destas proteínas, incluindo concentração dos polímeros, pH, adição de sal e temperatura foi investigada. Os resultados desta pesquisa demonstraram a importância das características da proteína na partição em sistemas bifásicos aquosos.

  3. Extraction protease expressed by Penicillium fellutanum from the Brazilian savanna using poly(ethylene glycol)/sodium polyacrylate/NaCl aqueous two-phase system.

    Science.gov (United States)

    Barros, Kleber V G; Souza, Paula M; Cardoso, Samuel L; Borges, Leonardo L; Filho, Edivaldo X F; Junior, Adalberto P; Magalhães, Pérola O

    2015-01-01

    The partitioning of protease expressed by Penicillium fellutanum from the Brazilian savanna in a novel inexpensive and stable aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and sodium polyacrylate (NaPA) was studied in this work using factorial design. The ATPS is formed by mixing both polymers with a salt (NaCl) and fermented broth of P. fellutanum. The effects of molar mass (2,000, 4,000, and 6,000 g ⋅ mol(-1)) and concentration (6, 8, and 10 wt%) of PEG and that of NaPA concentration (6, 8, and 10 wt%) on protease partitioning (K) at 25 °C were studied. A two-level factorial design (2(3)) was implemented. The effect of Na2 SO4 concentration (5, 10, and 15 wt%) on the reextraction of the enzyme was also analyzed. The partition coefficient K ranged from 77.51 to 1.21, indicating the versatility of the method. The reextraction was achieved with the addition of 5% Na2 SO4 , allowing the partitioning of the protease to the upper phase, whereas total proteins were directed to the bottom phase. The results of partitioning using the PEG/NaPA/NaCl system and that of the subsequent reextraction with Na2 SO4 suggest that this method can be used to purify proteases from fermented broth of P. fellutanum. PMID:25546578

  4. Partition of Chiral pharmaceutical intermediate R(-)-Mandelic Acid in Aqueous Two-Phase System of Poly(ethylene glycol)-Ammonium Sulfate

    Institute of Scientific and Technical Information of China (English)

    Xu Xiaoping; Li Zhongqin; Chen Jiebo; Huang Xinghua

    2004-01-01

    An aqueous two-phase system of poly (ethylene glycol)-ammonium sulfate was employed to separate R (-)-mandelic acid.The result showed that R (-)-mandelic acid has priority to partition in PEG-rich top phase. This indicated that aqueous two-phase is a very suitable system for separation of R(-)-mandelic acid.

  5. Polyethylene glycol-grafted polystyrene particles

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    OpenAIRE

    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 ...

  7. Condensation of Self-Assembled Lyotropic Chromonic Liquid Crystal Sunset Yellow in Aqueous Solutions Crowded with Polyethylene Glycol and Doped with Salt

    Energy Technology Data Exchange (ETDEWEB)

    Park, Heung-Shik; Kang, Shin-Woong; Tortora, Luana; Kumar, Satyendra; Lavrentovich, Oleg D. (Chonbuk); (Kent)

    2012-10-10

    We use optical and fluorescence microscopy, densitometry, cryo-transmission electron microscopy (cryo-TEM), spectroscopy, and synchrotron X-ray scattering to study the phase behavior of the reversible self-assembled chromonic aggregates of an anionic dye Sunset Yellow (SSY) in aqueous solutions crowded with an electrically neutral polymer polyethylene glycol (PEG) and doped with the salt NaCl. PEG causes the isotropic SSY solutions to condense into a liquid-crystalline region with a high concentration of SSY aggregates, coexisting with a PEG-rich isotropic (I) region. PEG added to the homogeneous nematic (N) phase causes separation into the coexisting N and I domains; the SSY concentration in the N domains is higher than the original concentration of PEG-free N phase. Finally, addition of PEG to the highly concentrated homogeneous N phase causes separation into the coexisting columnar hexagonal (C) phase and I phase. This behavior can be qualitatively explained by the depletion (excluded volume) effects that act at two different levels: at the level of aggregate assembly from monomers and short aggregates and at the level of interaggregate packing. We also show a strong effect of a monovalent salt NaCl on phase diagrams that is different for high and low concentrations of SSY. Upon the addition of salt, dilute I solutions of SSY show appearance of the condensed N domains, but the highly concentrated C phase transforms into a coexisting I and N domains. We suggest that the salt-induced screening of electric charges at the surface of chromonic aggregates leads to two different effects: (a) increase of the scission energy and the contour length of aggregates and (b) decrease of the persistence length of SSY aggregates.

  8. Study on aqueous two-phase extraction of L-phenylalanine by polyethylene glycol/salt system%聚乙二醇/盐双水相萃取L-苯丙氨酸的研究

    Institute of Scientific and Technical Information of China (English)

    孙晨; 刘文举; 刘宁宁

    2012-01-01

    研究了聚乙二醇/盐双水相体系的成相行为及L-苯丙氨酸在双水相中的分配规律,其中包括聚乙二醇的分子量、聚乙二醇质量分数、盐的种类及加入量、L-苯丙氨酸初始浓度和pH对萃取分离的影响。当聚乙二醇1000的质量分数为27%,磷酸氢二钾的质量浓度为O.15g/mL,L-苯丙氨酸的质量浓度为10g/L,体系的pH为8.5时,L-苯丙氨酸的萃取率最高为99.5%,分配系数最大为186.5。%An aqueous two- phase system of polyethylene glycol (PEG)/salt with the behavior of forming aqueous two-phase and the distribution rules of L-phenylalanine in the aqueous two-phase system were studied.Effects of the molecular weight of polyethylene glycol ,the mass fraction of polyethylene glycol ,the types and concentrations of salts,the initial concentration of L-phenylalanine and pH value were investigated.When the mass fraction of PEG1000 was 27% ,the mass concentration of K2HPO4was 0.]5g/mL,the initial concentration of L-phenylalanine was 10g/L and pH value was about 8.5,the highest extraction yield of L-phenylalanine could reach 99.5 %, partition coefficient of L-phenylalanine could reach 186.5.

  9. A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat, E-mail: rsadeghi@uok.ac.ir [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of); Shahabi, Somayyeh [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2011-09-15

    Graphical abstract: Apparent molar volume against molality: o, {center_dot}, and {Delta}, respectively in water, (1 and 4) wt% PEG solution at 293.15 K; x, {Delta}, and lozenge, respectively in water, (1 and 4) wt% PEG solution at 313.15 K. Research Highlights: > C{sub 12}H{sub 25}SO{sub 3}Na(SDSn) was seen to interact with PEG more weakly than C{sub 12}H{sub 25}SO{sub 4}Na(SDS). > The constraints on molecular mobility of SDS micelles are larger than those of SDSn. > Entropy change on micellization for SDSn is larger than those for SDS. > Micelle formation of SDS is less endothermic and more spontaneous than that of SDSn. > Micelles of SDS have smaller aggregation number than that of SDSn. - Abstract: The density, sound velocity, and conductivity measurements were performed on aqueous solutions of sodium dodecyl sulfate (C{sub 12}H{sub 25}SO{sub 4}Na) or sodium dodecyl sulfonate (C{sub 12}H{sub 25}SO{sub 3}Na) in the absence and presence of poly(ethylene glycol) (PEG) at different temperatures. Changes in the apparent molar volumes and isentropic compressibilities upon micellization were derived using a pseudophase-transition approach and the infinite dilution apparent molar properties of the monomer and micellar form of C{sub 12}H{sub 25}SO{sub 4}Na and C{sub 12}H{sub 25}SO{sub 3}Na were determined. Variations of the critical micelle concentrations (CMCs) of both surfactants in the solutions investigated with temperature were obtained from which thermodynamic parameters of micellization were estimated. It was found that at low temperature the micelle formation process is endothermic and therefore, this process must be entropically driven. However, upon increasing the temperature, the enthalpic factor becomes more significant and, at temperatures higher than 303.15 K the micellization is enthalpy driven. The interactions between C{sub 12}H{sub 25}SO{sub 4}Na/C{sub 12}H{sub 25}SO{sub 3}Na and PEG were studied and it was found that sodium alkyl sulfonates were seen

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

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    Hydrogel microspheres, e.g. for the use as protein carriers, can be prepared without the use of organic solvents via an emulsified aqueous two phase system (ATPS) that is based on two immiscible polymer solutions. The type and concentration of the polymers can affect the ATPS and finally the dist......Hydrogel microspheres, e.g. for the use as protein carriers, can be prepared without the use of organic solvents via an emulsified aqueous two phase system (ATPS) that is based on two immiscible polymer solutions. The type and concentration of the polymers can affect the ATPS and finally...... the distribution of incorporated drugs between the aqueous phases. For the preparation of hydrogel microspheres based on hydroxyethyl starch-hydroxyethyl methacrylate (HES-HEMA), hydroxyethyl starch-methacrylate (HES-MA), and hydroxyethyl starch-polyethylene glycol methacrylate (HES-P(EG)6MA), polyethylene glycol...... of hydrogel microspheres by an aqueous-two-phase preparation process....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-15

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

  14. Poly(ethylene glycol)-poly(L -lactide) star block copolymer hydrogels crosslinked by metal-ligand coordination

    NARCIS (Netherlands)

    Buwalda, S.J.; Dijkstra, P.J.; Feijen, J.

    2012-01-01

    The aqueous solution behavior and thermoreversible gelation properties of pyridine-end-functionalized poly(ethylene glycol)–poly(L-lactide) (PEG–(PLLA)8–py) star block copolymers in the presence of coordinating transition metal ions were studied. In aqueous solutions, the macromonomers self-assemble

  15. Selected polyethylene glycols as DOP substitutes. Addendum 1

    International Nuclear Information System (INIS)

    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

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  17. Phase Separation Behavior and System Properties of Aqueous Two-Phase Systems with Polyethylene Glycol and Different Salts: Experiment and Correlation

    OpenAIRE

    Haihua Yuan; Yang Liu; Wanqian Wei; Yongjie Zhao

    2015-01-01

    The phase separation behaviors of PEG1000/sodium citrate, PEG4000/sodium citrate, PEG1000/ammonium sulfate, and PEG4000/ammonium sulfate aqueous two-phase systems were investigated, respectively. There are two distinct situations for the phase separation rate in the investigated aqueous two-phase systems: one state is top-continuous phase with slow phase separation rate and strong bottom-continuous phase with fast phase separation rate and weak volume ratio dependence. The system properties s...

  18. Stabilization of Polyethylene Glycol in Archaeological Wood

    DEFF Research Database (Denmark)

    Mortensen, Martin Nordvig

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

  19. Radioimmunoprecipitation polyethylene glycol assay for circulating Entamoeba histolytica antigens

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-12-17

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

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

    Institute of Scientific and Technical Information of China (English)

    Jie Wen; Ren-xi Zhuo; Lu Wang

    1999-01-01

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

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

    OpenAIRE

    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...

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  4. Capture and utilization of carbon dioxide with polyethylene glycol

    CERN Document Server

    Yang, Zhen-Zhen; He, Liang-Nian

    2012-01-01

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

  5. Effective Antisense Gene Regulation via Noncationic, Polyethylene Glycol Brushes.

    Science.gov (United States)

    Lu, Xueguang; Jia, Fei; Tan, Xuyu; Wang, Dali; Cao, Xueyan; Zheng, Jiamin; Zhang, Ke

    2016-07-27

    Negatively charged nucleic acids are often complexed with polycationic transfection agents before delivery. Herein, we demonstrate that a noncationic, biocompatible polymer, polyethylene glycol, can be used as a transfection vector by forming a brush polymer-DNA conjugate. The brush architecture provides embedded DNA strands with enhanced nuclease stability and improved cell uptake. Because of the biologically benign nature of the polymer component, no cytotoxicity was observed. This approach has the potential to address several long-lasting challenges in oligonucleotide therapeutics. PMID:27420413

  6. Effect of polyethylene glycol on characteristics of chitosan membranes

    Directory of Open Access Journals (Sweden)

    Puthai, W.

    2005-07-01

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

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

    Science.gov (United States)

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

    2016-09-01

    The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function. PMID:27603372

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

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  9. Polyethylene glycol diffusion in ex vivo skin tissue

    Science.gov (United States)

    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.

  10. Isothermal Crystallization Kinetics of Microencapsulated Polyethylene Glycol Particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Wen Zhong

    2010-10-01

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

  12. On the Structure of Holographic Polymer-dispersed Polyethylene Glycol

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    Yukio Nagasaki

    2010-01-01

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

  14. Characterization of indomethacin release from polyethylene glycol tablet fabricated with mold technique

    Directory of Open Access Journals (Sweden)

    Mesnukul A

    2010-01-01

    Full Text Available The purpose of this study was to use polyethylene glycol as a carrier to improve the solubility of an aqueous insoluble drug by melting and molding method. The release of dissolved drug was designed to be subsequently sustained with an addition of xanthan gum. The release of indomethacin from the developed system into phosphate buffer pH 6.2 was conducted using the dissolution apparatus. This carrier system could effectively enhance the solubility of indomethacin and an addition of xanthan gum could sustain the drug release. Eudragit L100 film coating could protect the carrier not to be disturbed with HCl buffer pH 1.2 and could dissolve in phosphate buffer pH 6.2, therefore, the drug release from coated tablet was initially very low but subsequently gradually released and prolonged in phosphate buffer pH 6.2. Differential scanning calorimetry study indicated the amorphous state of drug in polyethylene glycol carrier. Scanning electron microscopy photomicrograph indicated the drug diffusion outward through the porous network of matrix tablets into the dissolution fluid and curve fitting signified that the drug release kinetic was Fickian diffusion.

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

    Science.gov (United States)

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

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

  16. Immediate-type hypersensitivity to polyethylene glycols: a review.

    Science.gov (United States)

    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. Capture and utilization of carbon dioxide with polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    Wang Li-Li

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Yadollah Abdollahi

    2012-05-01

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

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

    OpenAIRE

    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...

  1. Non-Covalent Functionalization of Carbon Nanotubes by Fluorescein-Polyethylene Glycol: Supramolecular Conjugates with pH Dependent Absorbance and Fluorescence

    OpenAIRE

    Nakayama-Ratchford, Nozomi; Bangsaruntip, Sarunya; Sun, Xiaoming; Welsher, Kevin; Dai, Hongjie

    2007-01-01

    We report the use of fluorescein-polyethylene glycol (Fluor-PEG) to non-covalently functionalize single-walled carbon nanotubes (SWNTs) for obtaining aqueous-soluble nanotube conjugates (Fluor-PEG/SWNT) and simultaneously affording fluorescence labels to nanotubes. We find serendipitously that fluorescein, a widely used fluorophore, can strongly adsorb onto the sidewall of the SWNTs likely via π-stacking, and the hydrophilic PEG chain imparts high aqueous solubility. Interaction between fluor...

  2. Synthesis and photophysicochemical studies of poly(ethylene glycol) conjugated symmetrical and asymmetrical zinc phthalocyanines

    Science.gov (United States)

    Dinçer, Hatice; Mert, Humeyra; Çalışkan, Emel; Atmaca, Göknur Yaşa; Erdoğmuş, Ali

    2015-12-01

    Synthesis and characterization of poly(ethylene glycol) conjugated symmetrical and asymmetrical zinc phthalocyanines (ZnPcs) is described. Copper (I) catalyzed azide-alkyne cycloaddition (CuAAC) click reaction between azide functional methoxypoly(ethylene glycol) (mPEG-N3) and tetra terminal alkynyl substituted ZnPc yields star polymer with ZnPc core. Furthermore, CuAAC click reaction between asymmetrically terminal alkynyl substituted zinc phthalocyanine (aZnPc) and mPEG-N3 yields aZnPc end functionalized PEG. Spectral, photophysical (fluorescence quantum yield), photochemical (singlet oxygen (ΦΔ), and photodegradation quantum yield (Φd) properties of the symmetrically, and asymmetrically PEGylated ZnPcs are investigated to be used as sensitizers in photodynamic therapy (PDT). The quantum yield values of fluorescence (ΦF) and singlet oxygen generation (ΦΔ) for water soluble symmetrically PEGylated ZnPc in aqueous solution are calculated as 0.01 and 0.14 respectively, suggesting its potential as photosensitizer in PDT treatment.

  3. Clinical usefulness of TSAb assay with high polyethylene glycol concentrations.

    Science.gov (United States)

    Ochi, Y; Inui, T; Kouki, T; Yamashiro, K; Takasu, N; Kajita, Y; Sato, Y; Nagata, A

    1999-01-01

    We previously demonstrated the stimulatory effect of polyethylene glycol (PEG) on thyroid-stimulating antibody (TSAb)-IgG-stimulated cAMP production (thyroid stimulating (TS) index) in porcine thyroid cell (PTC) assay. In the present study the clinical usefulness of the practical method using high PEG concentrations was examined. TS activity using PEG 22.5% precipitated fraction (PF) was significantly higher compared to standard TSAb activity using 12.5% PF from TSAb-positive serum, but the maximum TS activity was observed with PEG 12.5% PF + 4% PEG or PEG 22.5% PF + 2% PEG. In all cases of untreated Graves' patients, TSAb activity determined by PEG 22.5% PF was higher compared to standard TSAb activity using PEG 12. 5% PF from test serum, but the highest TSAb activity was observed by PEG 12.5% PF + 4% PEG without increased cAMP production to normal serum. TSAb was positive in 85% (40/47), 98% (46/47) and 100% (47/47) of untreated Graves' patients by the method of PEG 12.5% PF, PEG 22.5% PF and PEG 12.5% + 4% PEG, respectively. Increased TSAb activity by PEG 12.5% PF + 4% PEG method was also observed even if the standard TSAb activity using PEG 12.5% PF method was negative in the euthyroid states of Graves' patients during antithyroid drug therapy. The stimulatory effect of PEG on TS activity was not found in other thyroidal diseases [thyroiditis chronica (with high serum TSH), thyroid stimulation-blocking antibody (TSBAb)-positive sera (with low serum TSH), adenomatous goiter, subacute thyroiditis, and thyroid cancer]. The stimulatory effect of 5% PEG on TS activity produced directly by small amounts of Graves' serum (50 microl) was also found, although the sensitivity was lower than with PEG-precipitated IgG from 0.2 ml serum. The clinical usefulness of the sensitive TSAb assay using PEG-precipitated IgG or direct serum assay in the presence of high PEG concentrations was demonstrated. PMID:10461020

  4. Engineering Poly(ethylene glycol) Materials to Promote Cardiogenesis

    Science.gov (United States)

    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

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

    OpenAIRE

    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, ...

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

    Science.gov (United States)

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

    2015-07-01

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

  7. Marangoni effects in aqueous polypropylene glycol foams.

    Science.gov (United States)

    Tan, Su Nee; Fornasiero, Daniel; Sedev, Rossen; Ralston, John

    2005-06-15

    The foam behavior of three polypropylene glycols covering the molecular weight range between 192 and 725 g/mol has been examined. Static and dynamic surface tension data, as well as bubble size distribution and retention time in the foam, were incorporated into a simple model of foam stability. The latter clearly indicates that surface tension differences between the plateau border and lamellar region adjacent to the bubble surface are the dominant factor in controlling foamability, causing liquid flow in the direction opposite to liquid drainage, a process termed the Marangoni effect.

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Aoife O'Connor

    2014-10-01

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

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

    Science.gov (United States)

    Fu, Guopeng; Dempsey, Janel; Kyu, Thein

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

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

    OpenAIRE

    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...

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

    Science.gov (United States)

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

    2013-09-01

    Halo-ester-functionalized poly(ethylene glycol)s (PEGs) are successfully prepared by the transesterification of alkyl halo-esters with PEGs using Candida antarctica lipase B (CALB) as a biocatalyst under the solventless conditions. Transesterifications of chlorine, bromine, and iodine esters with tetraethylene glycol monobenzyl ether (BzTEG) are quantitative in less than 2.5 h. The transesterification of halo-esters with PEGs are complete in 4 h. (1) H and (13) C NMR spectroscopy with MALDI-ToF and ESI mass spectrometry confirm the structure and purity of the products. This method provides a convenient and "green" process to effectively produce halo-ester PEGs. PMID:23877930

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

    DEFF Research Database (Denmark)

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

    1985-01-01

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

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

    Science.gov (United States)

    Pasanphan, Wanvimol; Rattanawongwiboon, Thitirat; Rimdusit, Pakjira; Piroonpan, Thananchai

    2014-01-01

    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.

  15. Cationic cellulose hydrogels cross-linked by poly(ethylene glycol): Preparation, molecular dynamics, and adsorption of anionic dyes.

    Science.gov (United States)

    Kono, Hiroyuki; Ogasawara, Kota; Kusumoto, Ryo; Oshima, Kazuhiro; Hashimoto, Hisaho; Shimizu, Yuuichi

    2016-11-01

    Cationic cellulose hydrogels (CCGs) were prepared from quaternized celluloses with degrees of substitution (DS) of 0.56, 0.84, and 1.33, by the cross-linking reaction with poly(ethylene glycol) diglycidyl ether as a cross-linker. The CCGs exhibited swelling behavior in aqueous solutions, which was not affected by pH and temperature of the solution because of the presence of quaternary ammonium groups in their structures. The CCGs showed adsorption ability toward anionic dyes in aqueous solution, which increased with increasing DS. The dye adsorption was found to follow the pseudo-second order kinetic model and the equilibrium isotherm data can be described by the Langmuir adsorption model. In addition, the CCGs could be regenerated and proved to be recyclable adsorbents for wastewater treatment. PMID:27516262

  16. Poly(ethylene glycol)-containing hydrogel surfaces for antifouling applications in marine and freshwater environments

    NARCIS (Netherlands)

    Ekblad, T.; Bergström, G.; Ederth, T.; Conlan, S.L.; Mutton, R.; Clare, A.S.; Wang, S.; Liu, Y.; Zhao, Q.; D'Souza, F.; Donnelly, G.T.; Willemsen, P.R.; Pettitt, M.E.; Callow, M.E.; Callow, J.A.; Liedberg, B.

    2008-01-01

    This work describes the fabrication, characterization, and biological evaluation of a thin protein-resistant poly(ethylene glycol) (PEG)-based hydrogel coating for antifouling applications. The coating was fabricated by free-radical polymerization on silanized glass and silicon and on polystyrene-co

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

    Science.gov (United States)

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

    2015-01-01

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

  18. Increased permeability for polyethylene glycols through skin compromised by sodium lauryl sulphate

    NARCIS (Netherlands)

    I. Jakasa; M.M. Verberk; A.L. Bunge; J. Kruse; S. Kezic

    2006-01-01

    In this in vivo human study we assessed the influence of skin damage by sodium lauryl sulphate (SLS) on percutaneous penetration of polyethylene glycols (PEGs) of different molecular weights (MW). Percutaneous penetration of PEGs was determined using tape stripping of the stratum corneum (SC). The f

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

    DEFF Research Database (Denmark)

    Wei, Jiang; Bagge, Dorthe; Gram, Lone;

    2003-01-01

    The surface of AISI 316 grade stainless steel (SS) was modified with a layer of poly(ethylene glycol) (PEG) (molecular weight 5000) with the aim of preventing protein adsorption and bacterial adhesion. Model SS substrates were first modified to introduce a very high density of reactive amine grou...

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

    Indian Academy of Sciences (India)

    Wen Ye; Hong Jiang; Xian-Cao Yang

    2011-05-01

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

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Jun Araki

    2014-12-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

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

  5. Biodegradable Poly (Lactic-co-Glycolic Acid)-Polyethylene Glycol Nanocapsules: An Efficient Carrier for Improved Solubility, Bioavailability, and Anticancer Property of Lutein.

    Science.gov (United States)

    Arunkumar, Ranganathan; Prashanth, Keelara Veerappa Harish; Manabe, Yuki; Hirata, Takashi; Sugawara, Tatsuya; Dharmesh, Shylaja Mallaiah; Baskaran, Vallikannan

    2015-06-01

    Lutein bioavailability is limited because of its poor aqueous solubility. In this study, lutein-poly (lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG) nanocapsules were prepared to improve the solubility, bioavailability, and anticancer property of lutein. The scanning electron microscopy and dynamic light scattering examination revealed that the nanocapsules are smooth and spherical with size ranging from 80 to 500 nm (mean = 200 nm). In vitro lutein release profile from nanocapsules showed controlled sustainable release (66%) up to 72 h. Aqueous solubility of lutein nanocapsules was much higher by 735-fold than the lutein. Fourier transform infrared spectroscopy analyses showed no chemical interaction among PLGA, PEG, and lutein, indicating possible weak intermolecular forces like hydrogen bonds. X-ray diffraction revealed lutein is distributed in a disordered amorphous state in nanocapsules. Postprandial plasma kinetics (area under the curve) of an oral dose of lutein from nanocapsules was higher by 5.4-fold compared with that of micellar lutein (control). The antiproliferative effect of lutein from nanocapsules (IC50 value, 10.9 μM) was higher (43.6%) than the lutein (IC50 value, 25 μM). Results suggest that PLGA-PEG nanocapsule is an efficient carrier for enhancing hydrophilicity, bioavailability, and anticancer property of lipophilic molecules such as lutein.

  6. Laser processing of polyethylene glycol derivative and block copolymer thin films

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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

  9. Efficient lipid staining in plant material with sudan red 7B or fluorol [correction of fluoral] yellow 088 in polyethylene glycol-glycerol.

    Science.gov (United States)

    Brundrett, M C; Kendrick, B; Peterson, C A

    1991-01-01

    Polyethylene glycol (400) with 90% glycerol (aqueous) is introduced as an efficient solvent system for lipid stains. Various lipid-soluble dyes were dissolved in this solvent system and tested for their intensity, contrast, and specificity of staining of suberin lamellae in plant tissue. The stability (i.e., lack of precipitation) of the various staining solutions in the presence of fresh tissue was also tested. When dissolved in polyethylene glycol-glycerol, Sudan red 7B (fat red) was the best nonfluorescent stain and fluorol yellow 088 (solvent green 4) was an excellent fluorochrome. These two dyes formed stable staining solutions which efficiently stained lipids in fresh sections without forming precipitates. Estimations of the solubilities of these dyes in the solvent compared with their solubilities in lipids of various chemical types indicated that they should both be effective stains for lipids in general.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    1990-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Chen Jinghua; Chen Jingtao; Xu Zheng; Gu Qisheng

    2008-01-01

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

  13. Ultrafiltration – an alternative method to polyethylene glycol precipitation for macroprolactin detection

    OpenAIRE

    Beda-Maluga, Karolina; Pisarek, Hanna; Romanowska, Irena; Komorowski, Jan; Świętosławski, Jacek; Winczyk, Katarzyna

    2015-01-01

    Introduction The aim of the study was to evaluate two methods of macroprolactin (MaPRL) detection – precipitation with polyethylene glycol (PEG) and ultrafiltration and to compare these techniques with “gold standard” – gel filtration chromatography (GFC). Material and methods The study was conducted on 245 patients – 45 with organic and 200 with functional hyperprolactinaemia. In all the subjects MaPRL was detected by precipitation with PEG and ultrafiltration. Additionally, gel filtration c...

  14. Polyethylene glycol, unique among laxatives, suppresses aberrant crypt foci, by elimination of cells.

    OpenAIRE

    Taché, Sylviane; Parnaud, Géraldine; van Beek, Erik; Corpet, Denis E

    2006-01-01

    International audience OBJECTIVE: Polyethylene glycol (PEG), an osmotic laxative, is a potent inhibitor of colon cancer in rats. In a search for the underling mechanisms, the hypothesis that fecal bulking and moisture decrease colon carcinogenesis was tested. We also investigated the PEG effects on crypt cells in vivo. MATERIAL AND METHODS: Fischer 344 rats (n=272) were injected with the colon carcinogen, azoxymethane. They were then randomized to a standard AIN76 diet containing one of 19...

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

    OpenAIRE

    Álvaro A. Ramírez-Santos; Próspero Acevedo-Peña; Elcy M. Córdoba

    2012-01-01

    Titanium dioxide porous thin films on the Anatase phase were deposited onto glass slides by the sol-gel method assisted with polyethylene glycol (PEG). The dip-coated films were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA and DTG), UV-visible spectroscopy and X-ray diffraction (XRD). The photocatalytic activity of the films was determined by means of methyl-orange oxidation tests. The resultant PEG-modified films were crack-free and developed a poro...

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

    Directory of Open Access Journals (Sweden)

    Kim D. Janda

    2000-08-01

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

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

    Indian Academy of Sciences (India)

    Hemant V Chavan; Laxman K Adsul; Babasaheb P Bandgar

    2011-07-01

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

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

    OpenAIRE

    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...

  19. Stereoselective Synthesis of Polysubstituted Cyclopropanes from Poly(ethylene glycol)Supported Pyridinium Ylide

    Institute of Scientific and Technical Information of China (English)

    ZHAO Pan; LU Cui-fen; YANG Gui-chun; CHEN Zu-xing; DONG Nian-guo; SHI Jia-wei

    2011-01-01

    Polysubstituted cyclopropanes were efficiently prepared with poly(ethylene glycol)(PEG)as soluble support.The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile(R=CN)or ethyl arylidenecyanoacetate(R=COOEt)in the presence of triethylamine(TEA)afforded PEG-supported cyclopropanecarboxylates,which were cleaved by 1% KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.

  20. Fibrin-Loaded Porous Poly(Ethylene Glycol) Hydrogels as Scaffold Materials for Vascularized Tissue Formation

    OpenAIRE

    Jiang, Bin; Waller, Thomas M.; Larson, Jeffery C.; Appel, Alyssa A.; Eric M Brey

    2012-01-01

    Vascular network formation within biomaterial scaffolds is essential for the generation of properly functioning engineered tissues. In this study, a method is described for generating composite hydrogels in which porous poly(ethylene glycol) (PEG) hydrogels serve as scaffolds for mechanical and structural support, and fibrin is loaded within the pores to induce vascularized tissue formation. Porous PEG hydrogels were generated by a salt leaching technique with 100–150-μm pore size and thrombi...

  1. Cell fusion and intramembrane particle distribution in polyethylene glycol-resistant cells

    OpenAIRE

    1983-01-01

    The distribution of intramembrane particles (IMP) as revealed by freeze- fracture electron microscopy has been analyzed following treatment of mouse L cells and fusion-deficient L cell derivatives with several concentrations of polyethylene glycol (PEG). In cell cultures treated with concentrations of PEG below the critical level for fusion, no aggregation of IMP was observed. When confluent cultures of the parental cells are treated with 50% PEG, greater than 90% of the cells fuse, and cold-...

  2. Efficacy and Complications of Polyethylene Glycols for Treatment of Constipation in Children

    OpenAIRE

    Chen, Si-Le; Cai, Shi-Rong; Deng, Liang; Zhang, Xin-hua; Luo, Te-Dong; Peng, Jian-Jun; Xu, Jian-bo; Wen-feng LI; Chen, Chuang-Qi; Ma, Jin-ping; He, Yu-Long

    2014-01-01

    Abstract Constipation is a common childhood complaint. In 90% to 95% of children, constipation is functional, which means that there is no objective evidence of an underlying pathological condition. Polyethylene glycol (PEG or macrogol) solution is an osmotic laxative agent that is absorbed in only trace amounts from the gastrointestinal tract and routinely used to treat chronic constipation in adults. Here, we report the results of a meta-analysis of PEG-based laxatives compared with lactulo...

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

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  4. Fabrication of Off-the-Shelf Multilumen Poly(Ethylene Glycol) Nerve Guidance Conduits Using Stereolithography.

    Science.gov (United States)

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

    2011-01-01

    A manufacturing process for fabricating off-the-shelf multilumen poly(ethylene glycol) (PEG)-based nerve guidance conduits (NGCs) was developed that included the use of stereolithography (SL). A rapid fabrication strategy for complex 3D scaffolds incorporated postprocessing with lyophilization and sterilization to preserve the scaffold, creating an implantable product with improved suturability. SL is easily adaptable to changes in scaffold design, is compatible with various materials and cells, and can be expanded for mass manufacture. The fabricated conduits were characterized using optical and scanning electron microscopy, and measurements of swelling ratio, dimensional swelling factor, resistance to compression, and coefficient of friction were performed. Water absorption curves showed that the conduits after lyophilization and sterilization return easily and rapidly to a swollen state when placed in an aqueous solution, successfully maintaining their original overall structure as required for implantation. Postprocessed conduits at the swollen state were less slippery and therefore easier to handle than those without postprocessing. Suture pullout experiments showed that NGCs fabricated with a higher concentration of PEG were better able to resist suture pullout. NGCs having a multilumen design demonstrated a better resistance to compression than a single-lumen design with an equivalent surface area, as well as a greater force required to collapse the design. Conduits fabricated with a higher PEG concentration were shown to have compressive resistances comparable to those of commercially available NGCs. The use of SL with PEG and the manufacturing process developed here shows promise for improving the current state of the art in peripheral nerve repair strategies.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Definable surface chemistry is essential for many applications of microfluidic polymer systems. However, small cross-section channels with a high surface to volume ratio enhance passive adsorption of molecules that depletes active molecules in solution and contaminates the channel surface. Here, we...... to greatly improve cell adhesion compared to unexposed areas. This method opens for easy surface modification of closed microfluidic systems through combining a low protein binding PEG-based coating with spatially defined protein patterns of interest....... present a one-step photochemical process to coat the inner surfaces of closed microfluidic channels with a nanometer thick layer of poly(ethylene glycol) (PEG), well known to strongly reduce non-specific adsorption, using only commercially available reagents in an aqueous environment. The coating consists...

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

    Directory of Open Access Journals (Sweden)

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

    2009-01-01

    Full Text Available A simple two-step aqueous polymerization method was introduced to synthesize a polyacrylate/polyethylene glycol (PAC/PEG interpenetrating network (IPN hydrogel. On the basis of the effects of the ratio of PAC to PEG, neutralization degree, heavy-metal ion concentration, and temperature on the adsorption behavior of PAC/PEG IPN hydrogel toward Ni2 +, Cr3 + and Cd2 +, the preparation conditions were optimized. In our system, the greatest amount of Ni2 +, Cr3 + and Cd2 + adsorbed were 102.34, 49.38 and 33.41 mg g- 1, respectively. The adsorption abilities of a dried PAC/PEG composite and a swollen PAC/PEG IPN hydrogel were compared. It was found that the efficiency of removing metal ions using the swollen hydrogel was greater than that using the dried composite. The adsorption mechanism and model are also discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. In situ extraction of polar product of whole cell microbial transformation with polyethylene glycol-induced cloud point system.

    Science.gov (United States)

    Wang, Zhilong; Xu, Jian-He; Zhang, Wenzhi; Zhuang, Baohua; Qi, Hanshi

    2008-01-01

    A novel polyethylene glycol-induced cloud point system (PEG-CPS) was developed for in situ extraction of moderate polar product by setting a microbial transformation of benzaldehyde into L-phenylacetylcarbinol (L-PAC) with Saccharomyces cerevisiae (baker's yeast) as a model reaction. The biocompatibility of the microorganism in PEG-CPS was comparatively studied with a series of water-organic solvent two-phase partitioning systems. The tolerance of microorganism to the toxic substrate benzaldehyde was increased and the moderate polar product L-PAC was extracted into the surfactant-rich phase in the PEG-CPS. The novel PEG-CPS fills the gap of in situ extraction of polar product in microbial transformation left by water-organic solvent two-phase partitioning system. At the same time, the application of PEG-CPS in a microbial transformation also avoids expensive solvent when compared with that of aqueous two-phase system or CPS.

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

    Science.gov (United States)

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

    2010-11-20

    Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibitor in DMSO/water was used to build the structures. Porous and non-porous hydrogels with well-defined architectures and good mechanical properties were prepared. Porous hydrogel structures with a gyroid pore network architecture showed narrow pore size distributions, excellent pore interconnectivity and good mechanical properties. The structures showed good cell seeding characteristics, and human mesenchymal stem cells adhered and proliferated well on these materials.

  10. Partitioning of Bovine Serum Albumin in Polyethylene Glycol(PEG)/Phosphate Aqueous Two-Phase System%PEG/磷酸盐双水相系统萃取BSA的研究

    Institute of Scientific and Technical Information of China (English)

    胡松青; 李琳; 李冰; 肖蕾

    2002-01-01

    BSA partitioning was performed in the PEG/phosphate aqueous two-phase system. The effects of the phase compositions concentrations, addition of NaCl and the initial concentration of BSA on the partition coefficient K and the fraction of BSA in the bottom phase Y were investigated. The results showed that BSA was enriched to the bottom phase. The phase compositions of PEG 6000 mass fraction is 10%/PO3-4 mass fraction is 6% and PEG 10000 mass fraction is 6%/PO3-4 mass fraction is 6% respectively were desirable for partitioning. The addition of NaCl showed no influence on BSA partitioning in PEG 6000 mass fraction is 10% /PO3-4 mass fraction is 6% system. The mathematical model for K was derived from the initial mass concentration of BSA and well fitting with the experimental data.%以PEG/磷酸盐双水相系统萃取BSA为对象,研究了双水相系统成相浓度、外加盐NaCl、BSA起始浓度等对BSA在两相间的分配系数和BSA下相萃取率的影响.结果发现,BSA大部分被萃取入双水相体系的下相,成相组成为PEG 6000 10% (质量分数)/ PO3-4 6% (质量分数)和PEG 10000 6% (质量分数)/ PO3-4 6% (质量分数)的双水相系统有利于BSA的萃取分配;外加NaCl对PEG 6000 10%(质量分数)/PO3-4 6%(质量分数)系统萃取BSA的影响不大;得出了上、下相BSA浓度和BSA在两相间分配系数K与系统BSA起始浓度之间的表达式,与实验结果有较好的拟合.

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

    Directory of Open Access Journals (Sweden)

    Mazatusziha Ahmad

    2012-01-01

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

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

    Science.gov (United States)

    Chu, Qiuchen; Xu, Hong; Gao, Meng; Guan, Xin; Liu, Hongyan; Deng, Sa; Huo, Xiaokui; Liu, Kexin; Tian, Yan; Ma, Xiaochi

    2016-01-01

    Liver cancer remains a major problem around the world. Resibufogenin (RBG) is a major bioactive compound that was isolated from Chansu (also called toad venom or toad poison), which is a popular traditional Chinese medicine that is obtained from the skin secretions of giant toads. RBG has strong antitumor effects, but its poor aqueous solubility and its cardiotoxicity have limited its clinical use. The aim of this study was to formulate RBG-loaded poly(lactic-co-glycolic acid) (PLGA)-d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RPTN) to enhance the treatment of liver cancer. RPTN, RBG-loaded PLGA nanoparticle (RPN), and RBG/coumarin-6-loaded PLGA-d-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RCPTN) were prepared. The cellular uptake of RCPTN by HepG2 and HCa-F cells was analyzed using confocal laser scanning microscopy. Apoptosis was induced in HepG2 cells by RPTN, RBG solution (RS), and 5-fluorouracil solution (used as the negative controls), as assayed using flow cytometry. LD50 (median lethal dose) values were determined for RS and RPTN, and the liver-targeting properties were determined for RCPTN in intravenously injected mice. A pharmacokinetic study was conducted in rats, and the in vivo therapeutic effects of RPTN, RPN, and RS were examined in a mouse tumor model. The results showed that RCPTN simultaneously delivered both coumarin-6 and RBG into HepG2 and HCa-F cells. The ratio of apoptotic cells was increased in the RPTN group. The LD50 for RPTN was 2.02-fold higher than the value for RS. Compared to RS, RPTN and RPN both showed a significant difference in vivo not only in the pharmacodynamic study but also in anticancer efficacy, and RPTN performed much better than RPN. The detection indexes for drug concentration and fluorescence inversion microscopy images both demonstrated that RCPTN was much better at targeting the liver than RS. The liver-targeting RPTN, which displayed enhanced pharmacological effects and

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

    Directory of Open Access Journals (Sweden)

    Chu QC

    2016-01-01

    Full Text Available Qiuchen Chu,1,* Hong Xu,2,* Meng Gao,1 Xin Guan,1 Hongyan Liu,1 Sa Deng,1 Xiaokui Huo,1 Kexin Liu,1 Yan Tian,1 Xiaochi Ma1 1College of Pharmacy, 2College of Basic Medical Sciences, Dalian Medical University, Dalian, People’s Republic of China *These authors contributed equally to this work Abstract: Liver cancer remains a major problem around the world. Resibufogenin (RBG is a major bioactive compound that was isolated from Chansu (also called toad venom or toad poison, which is a popular traditional Chinese medicine that is obtained from the skin secretions of giant toads. RBG has strong antitumor effects, but its poor aqueous solubility and its cardiotoxicity have limited its clinical use. The aim of this study was to formulate RBG-loaded poly(lactic-co-glycolic acid (PLGA-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RPTN to enhance the treatment of liver cancer. RPTN, RBG-loaded PLGA nanoparticle (RPN, and RBG/coumarin-6-loaded PLGA-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticle (RCPTN were prepared. The cellular uptake of RCPTN by HepG2 and HCa-F cells was analyzed using confocal laser scanning microscopy. Apoptosis was induced in HepG2 cells by RPTN, RBG solution (RS, and 5-fluorouracil solution (used as the negative controls, as assayed using flow cytometry. LD50 (median lethal dose values were determined for RS and RPTN, and the liver-targeting properties were determined for RCPTN in intravenously injected mice. A pharmacokinetic study was conducted in rats, and the in vivo therapeutic effects of RPTN, RPN, and RS were examined in a mouse tumor model. The results showed that RCPTN simultaneously delivered both coumarin-6 and RBG into HepG2 and HCa-F cells. The ratio of apoptotic cells was increased in the RPTN group. The LD50 for RPTN was 2.02-fold higher than the value for RS. Compared to RS, RPTN and RPN both showed a significant difference in vivo not only in the pharmacodynamic study but also in

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

    Institute of Scientific and Technical Information of China (English)

    SUN Ruona; CHAI Zhikuan

    1988-01-01

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

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

    Science.gov (United States)

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

    2013-12-28

    Stimuli triggered polymers provide a variety of applications related with the biomedical fields. Among various stimuli triggered mechanisms, thermoresponsive mechanisms have been extensively investigated, as they are relatively more convenient and effective stimuli for biomedical applications. In a contemporary approach for achieving the sustained action of proteins, peptides and bioactives, injectable depots and implants have always remained the thrust areas of research. In the same series, Poloxamer based thermogelling copolymers have their own limitations regarding biodegradability. Thus, there is a need to have an alternative biomaterial for the formulation of injectable hydrogel, which must remain biocompatible along with safety and efficacy. In the same context, poly(ethylene glycol) (PEG) based copolymers play a crucial role as a biomedical material for biomedical applications, because of their biocompatibility, biodegradability, thermosensitivity and easy controlled characters. This review stresses on the physicochemical property, stability and composition prospects of smart PEG/poly(lactic-co-glycolic acid) (PLGA) based thermoresponsive injectable hydrogels, recently utilized for biomedical applications. The manuscript also highlights the synthesis scheme and stability characteristics of these copolymers, which will surely help the researchers working in the same area. We have also emphasized the applied use of these smart copolymers along with their formulation problems, which could help in understanding the possible modifications related with these, to overcome their inherent associated limitations. PMID:24144918

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

    Science.gov (United States)

    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.

  17. Fabrication and Anti-Fouling Properties of Photochemically and Thermally Immobilized Poly(Ethylene Oxide) and Low Molecular Weight Poly(Ethylene Glycol) Thin Films

    OpenAIRE

    Wang, Hui; Ren, Jin; Hlaing, Aye; Yan, Mingdi

    2010-01-01

    Poly(ethylene oxide) (PEO) and low molecular weight poly(ethylene glycol) (PEG) were covalently immobilized on silicon wafers and gold films by way of the CH insertion reaction of perfluorophenyl azides (PFPAs) by either photolysis or thermolysis. The immobilization does not require chemical derivatization of PEO or PEG, and polymers of different molecular weights were successfully attached to the substrate to give uniform films. Microarrays were also generated by printing polymer solutions o...

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

    Directory of Open Access Journals (Sweden)

    Zehra Durmus

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    H. N. Cheng

    2012-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-04-30

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

  1. Synthesis of Dextran/Methoxy Poly(ethylene glycol) Block Copolymer

    OpenAIRE

    Young-Il Jeong; Dong-Gon Kim; Dae-Hwan Kang

    2013-01-01

    We synthesized a block copolymer composed of dextran and methoxy poly(ethylene glycol) (mPEG). To accomplish this, the end group of dextran was modified by reductive amination. The aminated dextran (Dextran-NH2) showed the intrinsic peaks of both dextran at 3~5.5 ppm and hexamethylene diamine at 1~2.6 ppm at 1H nuclear magnetic resonance (NMR) spectrum. The amino end group of dextran was conjugated with mPEG to make the block copolymer consisting of dextran/mPEG (abbre...

  2. Functional polyethylene glycol derivatives nanostructured thin films synthesized by matrix-assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Cristescu, R., E-mail: rodica.cristescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, Bucharest-Magurele (Romania); Popescu, C.; Popescu, A.; Grigorescu, S.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, Bucharest-Magurele (Romania); Mihaiescu, D. [University of Agriculture Sciences and Veterinary Medicine, 59 Marasti, Bucharest (Romania); Gittard, S.D.; Narayan, R.J. [Biomedical Engineering, University of North Carolina, Chapel Hill, NC (United States); Buruiana, T. [Petru Poni Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda, 41A, Iasi (Romania); Stamatin, I. [University of Bucharest, 3Nano-SAE Research Center, PO Box MG-38, Bucharest-Magurele (Romania); Chrisey, D.B. [Rensselaer Polytechnic Institute, Department of Materials Science and Engineering, Troy, NY (United States)

    2009-09-30

    We report the thin film deposition by matrix-assisted pulsed laser evaporation (MAPLE) of a polymer conjugate with an hydrophilic sequence between metronidazole molecules that was covalently attached to both oligomer ends of carboxylate poly(ethylene glycol) (PEG 1.5-metronidazole). A pulsed KrF* excimer laser was used to deposit the drug-polymer composite films. Fourier transform infrared spectroscopy was used to demonstrate that MAPLE-transferred materials exhibited chemical properties similar to the starting materials. The dependence of the surface morphology on incident laser fluence is given.

  3. Functional polyethylene glycol derivatives nanostructured thin films synthesized by matrix-assisted pulsed laser evaporation

    International Nuclear Information System (INIS)

    We report the thin film deposition by matrix-assisted pulsed laser evaporation (MAPLE) of a polymer conjugate with an hydrophilic sequence between metronidazole molecules that was covalently attached to both oligomer ends of carboxylate poly(ethylene glycol) (PEG 1.5-metronidazole). A pulsed KrF* excimer laser was used to deposit the drug-polymer composite films. Fourier transform infrared spectroscopy was used to demonstrate that MAPLE-transferred materials exhibited chemical properties similar to the starting materials. The dependence of the surface morphology on incident laser fluence is given.

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

    Directory of Open Access Journals (Sweden)

    Tomohiro Seki

    2015-03-01

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

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

    Science.gov (United States)

    Das, S.; Ghosh, A.

    2016-05-01

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

  6. Solubility of Naproxen in Polyethylene Glycol 200 + Water Mixtures at Various Temperatures

    OpenAIRE

    Panahi-Azar, Vahid; Soltanpour, Shahla; Martinez, Fleming; Jouyban, Abolghasem

    2015-01-01

    The solubility of naproxen in binary mixtures of polyethylene glycol 200 (PEG 200) + water at the temperature range from 298.0 K to 318.0 K were reported. The combinations of Jouyban-Acree model + van’t Hoff and Jouyban-Acree model + partial solubility parameters were used to predict the solubility of naproxen in PEG 200 + water mixtures at different temperatures. Combination of Jouyban-Acree model with van’t Hoff equation can be used to predict solubility in PEG 200 + water with only four so...

  7. Covalent Attachment of Poly(ethylene glycol) to Surfaces, Critical for Reducing Bacterial Adhesion

    DEFF Research Database (Denmark)

    Kingshott, Peter; Wei, Jiang; Bagge, Dorthe;

    2003-01-01

    The effects of different poly(ethylene glycol) (PEG) attachment strategies upon the adhesion of a Gram-negative bacteria (Pseudomonas sp.) was tested. PEG was covalently immobilized, at the lower critical solution temperature of PEG, to a layer of branched poly(ethylenimine) (PEI). PEI was both......F-SIMS analysis showed that both PEG surfaces adsorbed low but comparable levels of proteinaceous growth medium components (tryptic soy broth), as indicated by the addition of unique amino acid fragment ions in the spectra, most likely small peptides. Thus, bacterial adhesion was strongly dependent on the PEG...

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

    Institute of Scientific and Technical Information of China (English)

    Xi Cun WANG; Jun Ke WANG; Zheng LI

    2004-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Polyethylene glycols (PEGs) are attractive as excipients in the manufacture of drug products because they are water soluble and poorly immunogenic. They are used in various pharmaceutical preparations. However, because of their terminal hydroxyl groups, PEGs can participate in esterification...... reactions. In this study, kinetics of two active pharmaceutical ingredients, cetirizine and indomethacin possessing carboxylic acid functionality, has been studied in PEG 400 and PEG 1000 at 50°C, 60°C, 70°C, and 80°C. HPLC-UV was applied for the determination of concentrations in the kinetic studies...

  10. Influence of propylene glycol on aqueous silica dispersions and particle-stabilized emulsions.

    Science.gov (United States)

    Binks, Bernard P; Fletcher, Paul D I; Thompson, Michael A; Elliott, Russell P

    2013-05-14

    We have studied the influence of adding propylene glycol to both aqueous dispersions of fumed silica nanoparticles and emulsions of paraffin liquid and water stabilized by the same particles. In the absence of oil, aerating mixtures of aqueous propylene glycol and particles yields either stable dispersions, aqueous foams, climbing particle films, or liquid marbles depending on the glycol content and particle hydrophobicity. The presence of glycol in water promotes particles to behave as if they are more hydrophilic. Calculations of their contact angle at the air-aqueous propylene glycol surface are in agreement with these findings. In the presence of oil, particle-stabilized emulsions invert from water-in-oil to oil-in-water upon increasing either the inherent hydrophilicity of the particles or the glycol content in the aqueous phase. Stable multiple emulsions occur around phase inversion in systems of low glycol content, and completely stable, waterless oil-in-propylene glycol emulsions can also be prepared. Accounting for the surface energies at the respective interfaces allows estimation of the contact angle at the oil-polar phase interface; reasonable agreement between measured and calculated phase inversion conditions is found assuming no glycol adsorption on particle surfaces.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2009-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Lixin Kuang

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

  15. Ultrafast Solvation Dynamics of Subtilisin-Polyethylene Glycol Interaction for Protein Crystallization

    Institute of Scientific and Technical Information of China (English)

    DING Qing; MENG Geng; WANG Shu-Feng; ZHENG Xiao-Feng; YANG Hong; GONG Qi-Huang

    2011-01-01

    We study the ultrafast solvation dynamics of protein-precipitant complexes. Protein subtilisin carlsberg (SC) was mixed with several polyethylene glycol (PEG) precipitants for protein crystallization. Picosecond-resolved emission spectra from single intrinsic tryptophan residue (Trp-113) are recorded to construct solvation correlation functions. For precipitant concentrations with various crystallization effects, we observe drastically different solvation relaxation processes. These differences in solvation dynamics are correlated with the local protein structural integrity and water-network stability upon interaction with the precipitants. The solvation dynamics at the protein surface is proposed as a new perspective to study precipitant-protein interactions.%@@ We study the ultrafast solvation dynamics of protein-precipitant complexes.Protein subtilisin earlsberg (SC) was mixed with several polyethylene glycol (PEG) precipitants for protein crystallization.Picosecond-resolved emission spectra from single intrinsic tryptophan residue (Trp-113) are recorded to construct solvation correlation functions.For precipitant concentrations with various crystallization effects, we observe drastically different solvation relaxation processes.These differences in solvation dynamics are correlated with the local protein structural integrity and water-network stability upon interaction with the precipitants.The solvation dynamics at the protein surface is proposed as a new perspective to study precipitant-protein interactions.

  16. Self-sterilized composite membranes of cellulose acetate/polyethylene glycol for water desalination.

    Science.gov (United States)

    Ahmad, Adnan; Jamshed, Fahad; Riaz, Tabinda; Gul, Sabad-E-; Waheed, Sidra; Sabir, Aneela; AlAnezi, Adnan Alhathal; Adrees, Muhammad; Jamil, Tahir

    2016-09-20

    Cellulose acetate/Polyethylene glycol-600 composite membranes were fabricated by two step phase inversion procedure and modified by in-situ reduction of silver nitrate. FTIR spectra demonstrated the existence of functional groups for bonding of silver with oxygen at 370cm(-1), 535cm(-1). The XRD diffractogram indicates characteristic peaks at 2θ values of 38.10°, 44.30°, 64.40°, and 77.30° which confirm the successful incorporation of silver within matrix of composite membranes. The morphology of composite membranes with appearances of spongy voids was exemplified from the scanning electron microscope. The atomic force microscopy was used to determine the increase in the surface roughness of the membranes. The increase in hydrophilicity, measured through contact angle, is rendered to the embedment of silver. The modification of membranes increased the flux from 0.80 to 0.95L/hr.m(2). The resulting membranes have outstanding ability to fight against gram negative Escherichia Coli and Bacillus Sabtilus. The novel cellulose acetate/polyethylene glycol membranes customized with silver have paved the path for evolution of axenic membranes. PMID:27261744

  17. The fabrication and option characteristics of polyethylene glycol-coated gold nanoparticles with different size

    International Nuclear Information System (INIS)

    Objective: To synthesize gold nanoparticles (GNPs) and polyethylene glycol-coated GNPs (PEG-GNPs)modified by sulfhydryl-polyethylene glycol (SH-PEG), chloroauric acid and different reductant agent,such as trisodium citrate and sodium borohydride were used. Methods: Chloroauric acid solution was brought to a boil,and then different volume of trisodium citrate solution or sodium borohydride solution was added to the boiling solution. Then the mixture was boiled for a further 30 minutes. Subsequently some SH-PEG was mixed with the GNPs and stirred for 1 hour to fabricate the PEG-GNPs. The optical characteristic and size of GNPs and PEG-GNPs were observed by UV-Vis spectrophotometer and transmission electron microscopic respectively. Results: 10, 25, and 45 nm GNPs were fabricated using 1% trisodium citrate,while the 5 nm GNPs were synthesized using 0.11% sodium borohydride. Meanwhile, SH-PEG was added to the GNPs and obtained the PEG-GNPs. Furthermore, when compared with the GNPs with different size,it can be found that the surface plasmon resonance (SPR) of GNPs have shift to long wavelength region with increasing particles size. The same phenomenon also can be found in the PEG-GNPs with different size. Conclusions: The size of GNPs can be modulated by controlling the ratio between chloroauric acid and trisodium citrate or sodium borohydride. Meanwhile, the larger the size of GNPs is, the more significant of the shifting to the long wavelength of SPR is. (authors)

  18. Chemical Modification of Recombinant Interleukin 2 by Polyethylene Glycol Increases Its Potency in the Murine Meth A Sarcoma Model

    Science.gov (United States)

    Katre, Nandini V.; Knauf, Michael J.; Laird, Walter J.

    1987-03-01

    Recombinant human interleukin 2 purified from Escherichia coli has limited solubility at neutral pH and a short circulatory half-life. This recombinant interleukin 2 was chemically modified by an active ester of polyethylene glycol. The modified interleukin 2 was purified by hydrophobic interaction chromatography and characterized by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and isoelectric focusing. This conjugate was compared to unmodified recombinant interleukin 2 in vitro and in vivo. Covalent attachment of the hydrophilic polymer polyethylene glycol enhanced the solubility of interleukin 2, decreased its plasma clearance, and increased its antitumor potency in the Meth A murine sarcoma model.

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

    Directory of Open Access Journals (Sweden)

    Ohashi N

    2012-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Brittany K. Myers

    2013-01-01

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

  1. Melatonin Nanoparticles Adsorbed to Polyethylene Glycol Microspheres as Activators of Human Colostrum Macrophages

    International Nuclear Information System (INIS)

    The effectiveness of hormones associated with polymeric matrices has amplified the possibility of obtaining new drugs to activate the immune system. Melatonin has been reported as an important immunomodulatory agent that can improve many cell activation processes. It is possible that the association of melatonin with polymers could influence its effects on cellular function. Thus, this study verified the adsorption of the hormone melatonin to polyethylene glycol (PEG) microspheres and analyzed its ability to modulate the functional activity of human colostrum phagocytes. Fluorescence microscopy and flow cytometry analyses revealed that melatonin was able to adsorb to the PEG microspheres. This system increased the release of superoxide and intracellular calcium. There was an increase of phagocytic and microbicidal activity by colostrum phagocytes when in the presence of melatonin adsorbed to PEG microspheres. The modified delivery of melatonin adsorbed to PEG microspheres may be an additional mechanism for its microbicidal activity and represents an important potential treatment for gastrointestinal infections of newborns.

  2. Effects of pH and ionic strength on precipitation of phytopathogenic viruses by polyethylene glycol.

    Science.gov (United States)

    Pastorek, J; Marcinka, K

    1989-01-01

    The effects of ionic strength of the solution (changed by varying NaCl concentrations or buffer molarity) on the precipitation with polyethylene glycol (PEG) 6000 were studied on phytopathogenic viruses of different morphology: the isometric red clover mottle virus (RCMV), rod-shaped tobacco mosaic virus, flexuous potato virus X (PVX) and bacilliform alfalfa mosaic virus. With increasing NaCl concentration or buffer molarity up to a certain level (0.1 mol/l), the efficiency of PEG precipitation increased. This relationship did not apply to PVX. The effects of pH on PEG precipitation were studied on RCMV. The efficiency of precipitation increased with decreasing difference between pH of the solution and pI of the virus. PMID:2565676

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

    Directory of Open Access Journals (Sweden)

    Álvaro A. Ramírez-Santos

    2012-01-01

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

  4. Sustained release of protein from poly(ethylene glycol) incorporated amphiphilic comb like polymers.

    Science.gov (United States)

    Srividhya, M; Preethi, S; Gnanamani, A; Reddy, B S R

    2006-12-01

    Amphiphilic comb like macromonomer containing hydrophilic poly(ethylene glycol) groups covalently linked to poly(hydromethyl siloxane) (PHMS) were prepared by hydrosilylation reaction. The epoxy reacting sites were introduced to this amphiphilic system by the reaction with allyl epoxy propyl ether (AEPE). Bovine serum albumin (BSA), a model protein drug was loaded to the PEG-PDMS system and very thin membranes were made from this macromonomer adopting solution casting technique. The in vitro protein release studies at various pH conditions showed a controlled release profile without exhibiting any initial burst. The control of the initial burst might be due to the strong linkages of the protein with the membrane and the aggregation of the protein at the surface. The morphology of the membrane before and after the protein release, and the mechanical strength were evaluated. The surface properties of the membrane were studied using the contact angle measurements. PMID:16930885

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

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    2007-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  9. Poly(lactic acid) / Poly(ethylene glycol) blends: Mechanical, thermal and morphological properties

    Science.gov (United States)

    Bijarimi, M.; Ahmad, S.; Rasid, R.; Khushairi, M. A.; Zakir, M.

    2016-04-01

    The poly(lactic acid) (PLA) was melt blended with linear polyethylene glycol (PEG) in an effort to increase the toughness of PLA. Melt blending was carried out in an internal mixer at 180 °C mixing temperature with 50 rpm for 15 minutes. The blends were characterized in terms of mechanical, thermal and morphological properties. It was found that tensile and flexural strength, stiffness and notched Izod impact strength decreased significantly when the PEG was added to the PLA matrix at 2.5-10% of PEG concentrations. Both glass transition and melting temperatures (Tg and Tm) lowered as the concentration of PEG was increased. Moreover, it was noted that the PLA/PEG blends showed a lower onset and peak degradation temperatures but with lower final degradation temperature as compared to the neat PLA. The morphological analysis revealed that the PEG was dispersed as droplets in the PLA matrix with a clear boundary between PLA matrix and PEG phases.

  10. Conductivity and characterization of plasticized polymer electrolyte based on (polyacrylonitrile-b-polyethylene glycol) copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yu-Hao; Chen, Chuh-Yung [Department of Chemical Engineering, National Cheng-Kung University, Tainan 70148 (China); Wang, Cheng-Chien [Department of Chemical and Material Engineering, Southern Taiwan University, Tainan 710 (China)

    2007-10-25

    A block copolymer polyacrylonitrile-b-polyethylene glycol was synthesized by the macroinitiator method. The copolymer mixed with a plasticizer - propylene carbonate (PC) and LiClO{sub 4} to form plasticized polymer electrolytes. FT-IR spectra show that the lithium ion interacts with the groups that contain the un-bonded electrons. The results of FT-IR also indicate that the EO segment can improve the dissociation of lithium salt. The differential scanning calorimeter (DSC) used to study the thermal behaviors of different compositions. In this study, the conductivity increases with the content of PEG. Additionally, the plasticized polymer electrolyte based on the block copolymer has a good conductivity and can retain good mechanical strength. (author)

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

    Science.gov (United States)

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

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    Science.gov (United States)

    Schmid, Holger

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-12

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

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

    Science.gov (United States)

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

    2006-09-01

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

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

    NARCIS (Netherlands)

    de Boer, T; Ensing, K

    1998-01-01

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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  1. Efficacy of polyethylene glycol adhesion barrier after gynecological laparoscopic surgery: Results of a randomized controlled pilot study.

    NARCIS (Netherlands)

    Broek, R.P. Ten; Kok-Krant, N.; Verhoeve, H.R.; Goor, H. van; Bakkum, E.A.

    2012-01-01

    Postoperative adhesions are the most frequent complication of peritoneal surgery, causing small bowel obstruction, female infertility and chronic pain. This pilot study assessed the efficacy of a sprayable polyethylene glycol (PEG) barrier in the prevention of de novo adhesions. 16 patients undergoi

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

    Science.gov (United States)

    Hajihashemi, Shokoofeh; Geuns, Jan M C

    2016-09-01

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

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

    Science.gov (United States)

    Hajihashemi, Shokoofeh; Geuns, Jan M C

    2016-09-01

    Stevia rebaudiana is a sweet herb of the Astraceae family, which is cultivated for the natural sweeteners it contains. The aim of this study was to assess the effect of drought, simulated by the application of polyethylene glycol (5%, 10%, and 15% w/v), on the content of steviol glycosides (SVglys) and transcription levels of six genes involved in the biosynthesis of these natural sweeteners. The transcription levels of ent-kaurene synthase, ent-kaurene oxidase, ent-kaurenoic acid hydroxylase, and three UDP-dependent glycosyltransferases, UGT85C2,UGT74G1 and UGT76G1 were downregulated under polyethylene glycol treatment. Polyethylene glycol treatment significantly decreased the amount of stevioside, rebaudioside A, B, C and F, steviolbioside, dulcoside A, rubusoside, and total SVglys. These results strongly suggest a close relationship of SVglys content with the transcription of genes involved in the SVglys biosynthesis pathway. Comparing the observations of the present study with other reports provided the knowledge that the Stevia response to drought stress can be influenced by different environmental and experimental factors, in addition to intensity of drought stress. In conclusion, these results strongly suggest that polyethylene glycol-induced drought stress has a negative effect on the content of SVglys and transcription of SVglys biosynthetic genes and that this should be investigated further. We recommend that sufficient irrigation of Stevia is required to obtain a high content of SVglys. PMID:27642557

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  6. Facile spectrophotometric assay of molar equivalents of N-hydroxysuccinimide esters of monomethoxyl poly-(ethylene glycol derivatives

    Directory of Open Access Journals (Sweden)

    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.

  7. Effect of Polyethylene Glycol Modification of TiO2 Nanoparticles on Cytotoxicity and Gene Expressions in Human Cell Lines

    Directory of Open Access Journals (Sweden)

    Shuji Sonezaki

    2012-03-01

    Full Text Available Nanoparticles (NPs are tiny materials used in a wide range of industrial and medical applications. Titanium dioxide (TiO2 is a type of nanoparticle that is widely used in paints, pigments, and cosmetics; however, little is known about the impact of TiO2 on human health and the environment. Therefore, considerable research has focused on characterizing the potential toxicity of nanoparticles such as TiO2 and on understanding the mechanism of TiO2 NP-induced nanotoxicity through the evaluation of biomarkers. Uncoated TiO2 NPs tend to aggregate in aqueous media, and these aggregates decrease cell viability and induce expression of stress-related genes, such as those encoding interleukin-6 (IL-6 and heat shock protein 70B’ (HSP70B’, indicating that TiO2 NPs induce inflammatory and heat shock responses. In order to reduce their toxicity, we conjugated TiO2 NPs with polyethylene glycol (PEG to eliminate aggregation. Our findings indicate that modifying TiO2 NPs with PEG reduces their cytotoxicity and reduces the induction of stress-related genes. Our results also suggest that TiO2 NP-induced effects on cytotoxicity and gene expression vary depending upon the cell type and surface modification.

  8. Surface polyethylene glycol conformation influences the protein corona of polyethylene glycol-modified single-walled carbon nanotubes: potential implications on biological performance.

    Science.gov (United States)

    Sacchetti, Cristiano; Motamedchaboki, Khatereh; Magrini, Andrea; Palmieri, Graziana; Mattei, Maurizio; Bernardini, Sergio; Rosato, Nicola; Bottini, Nunzio; Bottini, Massimo

    2013-03-26

    Investigation of the nanoparticle protein corona, the shell of plasma proteins formed around nanoparticles immediately after they enter the bloodstream, is a benchmark in the study of the applications of nanoparticles in all fields of medicine, from pharmacology to toxicology. We report the first investigation of the protein corona adsorbed onto single-walled carbon nanotubes modified with 2 kDa molecular weight polyethylene glycol chains [PEG(2k)-modified SWCNTs or PEG2-SWCNTs] by using a large-scale gel-based proteomics method on biological replicates. More than 240 plasma proteins were selected, and their differences were analyzed among PEG2-SWCNTs differing in surface charge and PEG conformation. The protein corona of PEG2-SWCNTs showed that coagulation proteins, immunoglobulins, apolipoproteins, and proteins of the complement system were among the proteins bound by PEG2-SWCNTs and that their recruitment was independent from the isoelectric point, molecular weight, total hydrophobicity, and number of polyaromatic residues of the proteins. Statistical analysis on protein relative abundance revealed that PEG conformation had a higher influence on the PEG2-SWCNTs' protein corona repertoire than nanotube surface charge. PEG conformation also affected the biological performance of PEG2-SWCNTs. A change in PEG conformation from mushroom to mushroom-brush transition affected the competitive adsorption of the major constituents of the protein corona of PEG2-SWCNTs and promoted shorter blood circulation time, faster renal excretion, and higher relative spleen versus liver uptake of PEG2-SWCNTs. Our data suggest that the protein corona, along with steric stabilization, may mediate the action of PEG conformation on the pharmacokinetic profile of PEG-modified SWCNTs. PMID:23413928

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

    Energy Technology Data Exchange (ETDEWEB)

    Wyrwas, Bogdan [Institute of Chemistry, Poznan University of Technology, Piotrowo 3, 60-965 Poznan (Poland); Chrzanowski, Lukasz, E-mail: lucaschrz@gmx.de [Institute of Chemical Technology and Engineering, Poznan University of Technology, Pl. M. Sklodowskiej-Curie 2, 60-965 Poznan (Poland); Lawniczak, Lukasz; Szulc, Alicja [Institute of Chemical Technology and Engineering, Poznan University of Technology, Pl. M. Sklodowskiej-Curie 2, 60-965 Poznan (Poland); Cyplik, Pawel; Bialas, Wojciech [Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences, Wojska Polskiego 48, 60-627 Poznan (Poland); Szymanski, Andrzej; Holderna-Odachowska, Aleksandra [Institute of Chemistry, Poznan University of Technology, Piotrowo 3, 60-965 Poznan (Poland)

    2011-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Gao D

    2012-07-01

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

  11. Efficacy and complications of polyethylene glycols for treatment of constipation in children: a meta-analysis.

    Science.gov (United States)

    Chen, Si-Le; Cai, Shi-Rong; Deng, Liang; Zhang, Xin-Hua; Luo, Te-Dong; Peng, Jian-Jun; Xu, Jian-Bo; Li, Wen-Feng; Chen, Chuang-Qi; Ma, Jin-Ping; He, Yu-Long

    2014-10-01

    Constipation is a common childhood complaint. In 90% to 95% of children, constipation is functional, which means that there is no objective evidence of an underlying pathological condition. Polyethylene glycol (PEG or macrogol) solution is an osmotic laxative agent that is absorbed in only trace amounts from the gastrointestinal tract and routinely used to treat chronic constipation in adults. Here, we report the results of a meta-analysis of PEG-based laxatives compared with lactulose, milk of magnesia (magnesium hydroxide), oral liquid paraffin (mineral oil), or acacia fiber, psyllium fiber, and fructose in children. This meta-analysis was conducted in accordance with PRISMA guidelines and involved searches of MEDLINE, Cochrane, EMBASE, and Google Scholar databases up to February 10, 2014, using the keywords (Constipation OR Functional Constipation OR Fecal Impaction) AND (Children) AND (Polyethylene Glycol OR Laxative). Primary efficacy outcomes included a number of stool passages/wk and percentage of patients who reported satisfactory stool consistency. Secondary safety outcomes included diarrhea, abdominal pain, nausea or vomiting, pain or straining at defecation, bloating or flatulence, hard stool consistency, poor palatability, and rectal bleeding. We identified 231 articles, 27 of which were suitable for full-text review and 10 of which were used in the meta-analysis. Patients who were treated with PEG experienced more successful disimpaction compared with those treated with non-PEG laxatives. Treatment-related adverse events were acceptable and generally well tolerated. PEG-based laxatives are effective and safe for chronic constipation and for resolving fecal impaction in children. Children's acceptance of PEG-based laxatives appears to be better than non-PEG laxatives. Optimal dosages, routes of administration, and PEG regimens should be determined in future randomized controlled studies and meta-analyses. PMID:25310742

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-08-19

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

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

    Science.gov (United States)

    Arcaute, Karina; Mann, Brenda; Wicker, Ryan

    2010-03-01

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

  14. Functional Polyethylene Glycol with Carboxyl-supported Platinum as an Efficient Catalysis System for the Hydrosilylation of Alkenes

    Institute of Scientific and Technical Information of China (English)

    程媛; 彭家建; 杨虎; 厉嘉云; 来国桥; 李小年

    2012-01-01

    A series of carboxylated long chain polyethylene glycols(abbreviated as PEGCOOH) has been synthesized and used to support chloroplatinic acid.These supported catalysts were then tested for their efficiency in the hydrosilylation of alkenes.The factors affecting their catalytic properties,e.g.relative molecular mass of polyethylene glycol,reaction temperature,platinum content,and type of alkenes,have been studied.It was found that the activity of the platinum catalyst decreased with increasing length of the polyethylene glycol chain,and increased with reaction temperature.Moreover,these catalysts could be reused several times without a noticeable decrease in activity or selectivity.The reaction pathway leading to excellent selectivity for the β-adduct of hydrosilylation of alkenes with triethoxysilane catalyzed by this catalysis system was discussed.

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

    Institute of Scientific and Technical Information of China (English)

    Rajesh S. Bejankiwar; Abir Basu; Max Cementi

    2004-01-01

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

  16. Physicochemical characterization and dissolution study of solid dispersions of Lovastatin with polyethylene glycol 4000 and polyvinylpyrrolidone K30.

    Science.gov (United States)

    Patel, R P; Patel, M M

    2007-01-01

    Solid dispersions in water-soluble carriers have attracted considerable interest as a means of improving the dissolution rate, and hence possibly bioavailability, of a range of hydrophobic drugs. The aim of the present study was to improve the solubility and dissolution rate of a poorly water-soluble drug, Lovastatin, by a solid dispersion technique. Solid dispersions were prepared by using polyethylene glycol 4000 (PEG 4000) and polyvinylpyrrolidone K30 (PVP K30) in different drug-to-carrier ratios. Dispersions with PEG 4000 were prepared by fusion-cooling and solvent evaporation, whereas dispersions containing PVP K30 were prepared by solvent evaporation technique. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, X-ray powder diffraction, and FT-IR spectroscopy. The aqueous solubility of Lovastatin was favored by the presence of both polymers. The negative values of the Gibbs free energy and enthalpy of transfer explained the spontaneous transfer from pure water to the aqueous polymer environment. Solid-state characterization indicated Lovastatin was present as amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure Lovastatin, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. This can be attributed to improved wettability and dispersibility, as well as decrease of the crystalline and increase of the amorphous fraction of the drug. Solid dispersion prepared with PVP showed the highest improvement in wettability and dissolution rate of Lovastatin. Even physical mixture of Lovastatin prepared with both polymers also showed better dissolution profile than that of pure Lovastatin. Tablets containing solid dispersion prepared with PEG and PVP showed significant improvement in the release profile Lovastatin compared with tablets containing Lovastatin without PEG or PVP. PMID:17484141

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

    Directory of Open Access Journals (Sweden)

    Tianjun Liu

    2012-05-01

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

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

    Science.gov (United States)

    Seo, Kwang Su

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

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

    Directory of Open Access Journals (Sweden)

    Ni P

    2011-11-01

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

  20. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light

    Science.gov (United States)

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P.; Lee, Jae Young

    2016-07-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation via a mixed-mode reaction with a small increase in temperature (~5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications.Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm-2) could induce gelation

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

    Institute of Scientific and Technical Information of China (English)

    Jiu Fang DUAN; Yu Bin ZHENG

    2006-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Kangcheng WANG; Wei HUANG; Yongfeng ZHOU; Deyue YAN

    2008-01-01

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

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

    Indian Academy of Sciences (India)

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

    2007-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-01

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

  5. Hepatocytes targeting of cationic liposomes modified with soybean sterylglucoside and polyethylene glycol

    Institute of Scientific and Technical Information of China (English)

    Xian-Rong Qi; Wen-Wei Yan; Jing Shi

    2005-01-01

    AIM: In this study, a hepatocyte-specific targeting technology was developed by modifying cationic liposomes with soybean sterylglucoside (SG) and polyethylene glycol (PEG) (C/SG/PEG-liposomes).METHODS: The liposomal transfection efficiencies in HepG22.2.15 cells were estimated with the use of fluorescein sodium (FS) as a model drug, by flow cytometry. The antisense activity of C/SG/PEG-liposomes entrapped antisense oligonucleotides (ODN) was determined as HBsAg and HBeAg in HepG2 2.2.15 cells by ELISA. The liposome uptake by liver and liver cells in mice was carried out after intravenous injection of 3H-labeled liposomes.RESULTS: C/SG-liposomes entrapped FS were effectively transfected into HepG2 2.2.15 cells in vitro. C/SG/PEGliposomes entrapped ODN, reduced the secretion of both HBsAg and HBeAg in HepG2 2.2.15 cells when compared to free ODN. After in vivo injection of 3H-labeled C/SG/PEG-liposomes, higher radiation accumulation was observed in the hepatocytes than non-parenchymal cells of the liver.CONCLUSION: C/SG/PEG-liposomes mediated gene transfer to the liver is an effective gene-delivery method for hepatocytes-specific targeting, which appears to have a potential for gene therapy of HBV infections.

  6. Mass spectrometric behaviour of carboxylated polyethylene glycols and carboxylated octylphenol ethoxylates.

    Science.gov (United States)

    Frańska, Magdalena; Zgoła, Agnieszka; Rychłowska, Joanna; Szymański, Andrzej; Łukaszewski, Zenon; Frański, Rafał

    2003-01-01

    Mass spectrometric behaviour of mono- and di-carboxylated polyethylene glycols (PEGCs and CPEGCs) and carboxylated octylphenol ethoxylates (OPECs) are discussed. The tendency for ionisation (deprotonation, protonation and cationisation by alkali metal cations) of carboxylated PEGs was compared with that of non-carboxylated correspondents by using both secondary ion mass spectrometry (SIMS) and electrospray ionisation (ESI). The fragmentation of the PEGCs and CPEGCs is discussed and also compared with their neutral correspondents, PEGs. The B/E mass spectra were recorded, using secondary ion mass spectrometry as a method for generation, for deprotonated and protonated molecules and molecules cationised by alkali metal cations. The fragmentation behaviour of PEGs is found to be different from that of CPEGCs, The presence of carboxylic groups may be confirmed not only by the determination of molecular weights of the ethoxylates studied, but also on the basis of the fragment ions formed. The metastable decomposition of the [OPEC-H](-) ions proceed through the cleavage of the bond between the octylphenol moiety and the ethoxylene chain leading to the octylphenoxy anions. It permits determination of the mass of the hydrophobic moiety of the studied carboxylated alkylphenol ethoxylate. ESI mass spectra recorded in the negative ion mode were found to be more suitable for the determination of the average molecular weight of carboxylated ethoxylates than SI mass spectra. PMID:12939494

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

    Institute of Scientific and Technical Information of China (English)

    Hatem ZGALLA(I); Kathy STEPPE; Raoul LEMEUR

    2005-01-01

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

  8. Effect of polyethylene glycol induced drought stress on physio-hormonal attributes of soybean

    International Nuclear Information System (INIS)

    Drought stress is a major abiotic constraint limiting crop production world wide. In current study, we investigated the adverse effects of drought stress on growth, yield and endogenous phytohormones of soybean. Polyethylene glycol (PEG) solutions of elevated strength (8% and 16%) were used for drought stress induction. Drought stress period span for two weeks each at pre and post flowering growth stage. It was observed that soybean growth and yield attributes significantly reduced under drought stress at both pre and post flowering period, while maximum reduction was caused by PEG (16%) applied at pre flowering time. The endogenous bioactive GA/sub 1/ and GA/sub 4/ content decreased under elevated drought stress. On the other hand, jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA) content increased under drought stress. On the basis of current study, we concluded that application of earlier drought stress severely reduced growth and yield attributes of soybean when compared to its later application. Furthermore, increases in the endogenous contents of JA, SA and ABA in response to drought stress demonstrate the involvement of these hormones in drought stress resistance. (author)

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

    Science.gov (United States)

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

    2015-12-14

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

  10. Limitations of the radioimmunoprecipitation polyethylene glycol assay (RIPEGA) for detection of filarial antigens in serum

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, R.G.; Alexander, E.; Adkinson, N.F. (Johns Hopkins Univ., Baltimore, MD (USA). School of Medicine); Hussain, R. (National Institutes of Health, Bethesda, MD (USA))

    1984-03-30

    The performance of the radioimmunoprecipitation polyethylene glycol assay (RIPEGA) was examined for quantitation of filarial antigens (Brugia malayi and Dirofilaria immitis) in serum from infected human and animal hosts and non-infected controls. Multiple PEG concentrations were employed to determine the level of non-specific binding (NSB) in non-exposed human sera (NEHS) containing no filarial antigen. The NSB observed when 3 different /sup 125/I-labelled IgG antibodies were added to 26 NEHS varied 3-fold and was correlated significantly with total serum IgM (r = 0.80, P < 0.005, n = 24) but not with serum IgA (r = 0.37) or IgG (r = 0.45). NSB levels were significantly reduced when a Fab'/sub 2/ fragment of the /sup 125/I-labelled antibody was used, but the correlation of NSB with total serum IgM remained significant (r = 0.57, P < 0.01). The presence of rheumatoid factor in NEHS sera also significantly increased NSB by an average of 3-fold. These effects eliminated the assay's ability to detect in sera from infected hosts filarial antigen the presence of which could be readily demonstrated by an immunoradiometric assay. The RIPEGA's precision (intra-assay coefficient of variation (CV) = 21% at 35% Bsub(max)) and reproducibility (inter-assay CV = 29% at 35% Bsub(max)) are less satisfactory than many alternative immunoassays.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2009-02-01

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

  13. Cryoprotection mechanisms of polyethylene glycols on lactate dehydrogenase during freeze-thawing.

    Science.gov (United States)

    Mi, Yanli; Wood, George; Thoma, Laura

    2004-01-01

    The purpose of this study was to explore the cryoprotection mechanisms of high molecular weight polyethylene glycols (PEGs) (eg, PEG 4000 and PEG 8000) on lactate dehydrogenase (LDH). Ultraviolet activity assays, circular dichroism (CD) spectroscopy, gel filtration, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), (14)C-PEG 4000 labeling and binding, and cryostage microscopic study were conducted. Different molecular weights and concentrations of PEGs in LDH formulations were treated by freeze-thawing. Higher molecular weights and concentrations of PEGs in LDH-PEG formulations obtained better activity and secondary structure recoveries of LDH after freeze-thawing. Insoluble aggregation of LDH was not observed in gel filtration studies. SDS-PAGE results suggested surface characteristic modifications of LDH by the larger molecular weight PEGs. The 14C-PEG 4000 labeling and binding study showed extensive nonspecific interactions between the PEG 4000 and LDH molecules in a concentration-dependent manner. The bound LDH-PEG 4000/free PEG 4000 ratio increased when LDH or PEG 4000 concentrations increased. Cryostage microscopic study showed that PEG 8000 delayed the ice crystallization and eutectic transition of LDH formulation. It appeared that multiple mechanisms were at work during PEGs' cryoprotection of LDH. It was unclear whether the delayed eutectic characteristics of PEGs contributed to LDH cryoprotection. The favorable interaction, rather than preferential exclusion, between LDH and PEGs (eg, 4000) cryoprotected LDH. PMID:15760107

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

    Science.gov (United States)

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

    2016-01-01

    In the present study, the construction of arrays on silicon for naked-eye detection of DNA dengue was demonstrated. The array was created by exposing a polyethylene glycol (PEG) silane monolayer to 254 nm ultraviolet (UV) light through a photomask. Formation of the PEG silane monolayer and photomodifed surface properties was thoroughly characterized by using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. The results of XPS confirmed that irradiation of ultraviolet (UV) light generates an aldehyde functional group that offers conjugation sites of amino DNA probe for detection of a specific dengue virus target DNA. Employing a gold enhancement process after inducing the electrostatic interaction between positively charged gold nanoparticles and the negatively charged target DNA hybridized to the DNA capture probe allowed to visualize the array with naked eye. The developed arrays demonstrated excellent performance in diagnosis of dengue with a detection limit as low as 10 pM. The selectivity of DNA arrays was also examined using a single base mismatch and noncomplementary target DNA. PMID:27571080

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

    Directory of Open Access Journals (Sweden)

    Redouan Mahou

    2012-02-01

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

  16. Surface patterned pH-sensitive fluorescence using β-cyclodextrin functionalized poly(ethylene glycol).

    Science.gov (United States)

    Kim, Sung Han; Sharker, Shazid Md; In, Insik; Park, Sung Young

    2016-08-20

    This paper reports the development of a pH-responsive molecular pattern that shows specific and selective affinity for particular host-guest interactions, and its use as a pH fluorescent sensor. The pH-responsive boronate ester is formed via interactions between the diol group of β-cyclodextrin (CD) and phenylboronic acid of poly(ethylene glycol), and is strategically designed to allow reversible formation of a molecular lining pattern. Printing on a versatile substrate provides a method to monitor the positioning of different molecules by using a pH-responsive boronate ester, allowing specific host-guest interactions on any surface. Confocal laser scanning microscopy, fluorescence spectroscopy, and (1)H NMR results indicate that the assembled CD monolayer can be removed by washing with an acidic pH buffer, demonstrating the presence of a boronate ester connective bridge, which is acid labile. Therefore, visualization of the pH-responsive fluorescence sensor using a rhodamine-CD complex allows straightforward discrimination between different molecules on any substrate, thus facilitating application of this sensor in clinical diagnostics and environmental monitoring. PMID:27178950

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

    Directory of Open Access Journals (Sweden)

    Fülöp Ibolya

    2015-12-01

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

  18. Polyethylene glycol dimethyl ether (PEGDME)-based electrolyte for lithium metal battery

    Science.gov (United States)

    Carbone, Lorenzo; Gobet, Mallory; Peng, Jing; Devany, Matthew; Scrosati, Bruno; Greenbaum, Steve; Hassoun, Jusef

    2015-12-01

    We propose in this work a polyethylene glycol dimethyl ether (MW 500) dissolving lithium trifluoromethansulfonate (LiCF3SO3) salt as suitable electrolyte media for a safe and efficient use of the lithium metal anode in battery. Voltammetry and galvanostatic tests reveal significant enhancement of the electrolyte characteristics, in terms of cycling life and chemical stability, by the addition of lithium nitrate (LiNO3) to the solution. Furthermore, PFG NMR measurements suggest the applicability of the electrolyte in battery in terms of ionic conductivity, lithium transference number, ionic-association degree and self-diffusion coefficient. Accordingly, the electrolyte is employed in a lithium battery using lithium iron phosphate as the selected cathode. The battery delivers a stable capacity of 150 mAh g-1 and flat working voltage of 3.5 V, thus leading to a theoretical energy density referred to the cathode of 520 Wh kg-1. This battery is considered a suitable energy storage system for advanced applications requiring both high safety and high energy density.

  19. Rheological and Biological Characteristics of Hyaluronic Acid Derivative Modified by Polyethylene Glycol

    Institute of Scientific and Technical Information of China (English)

    CHEN Jinghua; CHEN Jingtao; XU Zheng

    2008-01-01

    Hyaluronic acid (HA) was chemically modified by polyethylene glycol. Meanwhile,the dynamic mechanics properties of HA derivative and its viscoelastic changes were measured on 3ARES3 Rheometer (Japan) at 25 ℃. Dried cross-linked films of 10×10 mm2 were immersed in phosphate buffered saline(PBS: pH 7.4) at 37 ℃ with different time periods to measure its water content and in vitro degradation. Moreover, cell cultured solutions, which were in the different cultivation vesse with 1 mg/mL Solution of HA derivative as doing experimental sample for 2 d, 4 d and 7 d, were observed, respectively, by an inverted discrepancy microscope. The cell relative growth rate was analyzed with the SPSS10.0 mathematic statistic software. Based on the above experiments,structure-modified HA derivative can meet the requirements of biomaterials in view of rheological and degradation in vitro and cytotoxicity charactereistics from clinical medical aspect under this experiment conditions.

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

    Science.gov (United States)

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

    2014-09-14

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

  1. Biodistribution and pharmacokinetics of uniform magnetite nanoparticles chemically modified with polyethylene glycol

    Science.gov (United States)

    Ruiz, A.; Hernández, Y.; Cabal, C.; González, E.; Veintemillas-Verdaguer, S.; Martínez, E.; Morales, M. P.

    2013-11-01

    The influence of polyethylene glycol (PEG) grafting on the pharmacokinetics, biodistribution and elimination of iron oxide nanoparticles is studied in this work. Magnetite nanoparticles (12 nm) were obtained via thermal decomposition of an iron coordination complex as a precursor. Particles were coated with meso-2,3-dimercaptosuccinic acid (DMSA) and conjugated to PEG-derived molecules by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC) chemistry. Using a rat model, we explored the nanoparticle biodistribution pattern in blood and in different organs (liver, spleen and lungs) after intravenous administration of the product. The time of residence in blood was measured from the evolution of water proton relaxivities with time and Fe analysis in blood samples. The results showed that the residence time was doubled for PEG coated nanoparticles and consequently particle accumulation in liver and spleen was reduced. Post-mortem histological analyses showed no alterations in the liver and confirm heterogeneous distribution of NPs in the organ, in agreement with magnetic measurements and iron analysis. Finally, by successive magnetic resonance images we studied the evolution of contrast in the liver and measured the absorption, time of residence and excretion of nanoparticles in the liver during a one month period. On the basis of these results we propose different metabolic routes that determine the fate of magnetic nanoparticles.

  2. Carbohydrate-mediated polyethylene glycol conjugation of TSH improves its pharmacological properties.

    Science.gov (United States)

    Park, Anna; Honey, Denise M; Hou, Lihui; Bird, Julie J; Zarazinski, Christine; Searles, Michelle; Braithwaite, Christian; Kingsbury, Jonathan S; Kyazike, Josephine; Culm-Merdek, Kerry; Greene, Ben; Stefano, James E; Qiu, Huawei; McPherson, John M; Pan, Clark Q

    2013-03-01

    Thyrogen (thyrotropin alfa for injection), recombinant human TSH (rhTSH), has been successfully used to enhance diagnostic radioiodine scanning and thyroglobulin testing in the follow-up of patients with thyroid cancer and as an adjunctive treatment for radioiodine thyroid remnant ablation. However, the short half-life of rhTSH in the circulation requires a multidose regimen. We developed novel sialic acid-mediated and galactose-mediated conjugation chemistries for targeting polyethylene glycol (PEG) to the three N-linked glycosylation sites on the protein, to prolong plasma half-life by eliminating kidney filtration and potential carbohydrate-mediated clearance. Conjugates of different PEG sizes and copy numbers were screened for reaction yield, TSH receptor binding, and murine phamacokinetics/pharmacodynamics studies. The best performing of these products, a 40-kDa mono-PEGylated sialic acid-mediated conjugate, exhibited a 3.5-fold longer duration of action than rhTSH in rats, as a 5-fold lower affinity was more than compensated by a 23-fold extension of circulation half-life. Biochemical characterization confirmed conjugation through the sialic acids. Correlation of PEG distribution on the three N-linked glycosylation sites and the PEG effect on receptor binding supported the previously reported structure-function relationship of rhTSH glycosylation. This long-acting rhTSH has the potential to significantly improve patient convenience and provider flexibility while reducing potential side effects associated with a sudden elevation of serum TSH. PMID:23389953

  3. Macroporous interpenetrating network of polyethylene glycol (PEG) and gelatin for cartilage regeneration.

    Science.gov (United States)

    Zhang, Jingjing; Wang, Justin; Zhang, Hui; Lin, Jianhao; Ge, Zigang; Zou, Xuenong

    2016-01-01

    Poor mechanical properties hinder the application of hydrogels in cartilage tissue engineering. In this study, macroporous interpenetrating network (IPN) hydrogels of gelatin and polyethylene glycol (PEG) were fabricated for use as a functional biomaterial to support chondrocyte culture. The IPN structure enhanced mechanical properties, while the macroporous structure facilitated cell-cell interactions. The hydrogels had pore sizes around 80 μm with favorable interconnectivity, reduced volume swelling ratios, and nearly unchanged weight swelling ratios with increasing gelatin ratios. More significantly, the Young's modulus increased with increasing gelatin ratio, reaching a 5.3-fold increase (p  IPN-10% over that of the PEG group. Chondrocytes developed elongated and fibroblast morphologies with extensive cell-cell interaction throughout IPN hydrogels, compared with round, isolated aggregates in PEG hydrogels. The glycosaminoglycan (GAG) accumulation was significantly higher in IPN hydrogels than in PEG hydrogels at day 21 and day 28. Additionally, significantly higher gene expressions of collagen II (p  IPN-10% when compared with other groups. Overall, the macroporous IPN hydrogels showed strong tissue formation abilities and enhanced mechanical properties, demonstrating high potential as scaffolds for cartilage regeneration. PMID:27305040

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

    Science.gov (United States)

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

    2015-12-01

    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

  5. In vitro screening of potato against water-stress mediated through sorbitol and polyethylene glycol.

    Science.gov (United States)

    Gopal, Jai; Iwama, Kazuto

    2007-05-01

    With the objective to develop a practical and effective method of screening potato for drought tolerance, shoot and root growth in microtuber-derived plantlets was studied in vitro in three genotypes with known root mass production under field conditions. Different levels of water-stress were induced using five concentrations of either sorbitol or polyethylene glycol (PEG) in MS medium. Water potential of various media ranged from -0.80 MPa to -2.05 MPa. Water-stress in culture adversely affected plantlet growth, and genotypes differed for their responses. Genotype IWA-1 was less affected than IWA-3 and IWA-5. At the same level of water potential, sorbitol had lower adverse effect than PEG; the latter being sticky. Genotype x sorbitol and genotype x PEG interactions were significant. At 0.2 M sorbitol and 0.003 M PEG, IWA-1 had significantly more roots with higher total root length, root volume, as well as root-dry weight than those of IWA-3 and IWA-5, whereas the latter two genotypes were at par for all these characters. This pattern was similar to the reported pattern of these genotypes for root-dry weight under field conditions. It is concluded that in vitro screening of potato under specific and limited water-stress conditions may provide a system for effectively differentiating the genotypes for their expected root mass production under field conditions.

  6. Synthesis of Dextran/Methoxy Poly(ethylene glycol Block Copolymer

    Directory of Open Access Journals (Sweden)

    Young-Il Jeong

    2013-01-01

    Full Text Available We synthesized a block copolymer composed of dextran and methoxy poly(ethylene glycol (mPEG. To accomplish this, the end group of dextran was modified by reductive amination. The aminated dextran (Dextran-NH2 showed the intrinsic peaks of both dextran at 3~5.5 ppm and hexamethylene diamine at 1~2.6 ppm at 1H nuclear magnetic resonance (NMR spectrum. The amino end group of dextran was conjugated with mPEG to make the block copolymer consisting of dextran/mPEG (abbreviated as DexPEG. The synthesized aminated dextran and DexPEG were characterized using 1H NMR and gel permeation chromatography (GPC. The molecular weight and conjugation yield were estimated by comparing the intensity ratio of the proton peaks of the glucose molecule (4.9 ppm and 3.3~4.0 ppm to that of the ethylene group of mPEG (3.7 ppm. Abundant hydroxyl group in the dextran chain can be used as a source of bioactive agent conjugation.

  7. Poly(ethylene glycol)-containing hydrogel surfaces for antifouling applications in marine and freshwater environments.

    Science.gov (United States)

    Ekblad, Tobias; Bergström, Gunnar; Ederth, Thomas; Conlan, Sheelagh L; Mutton, Robert; Clare, Anthony S; Wang, Su; Liu, Yunli; Zhao, Qi; D'Souza, Fraddry; Donnelly, Glen T; Willemsen, Peter R; Pettitt, Michala E; Callow, Maureen E; Callow, James A; Liedberg, Bo

    2008-10-01

    This work describes the fabrication, characterization, and biological evaluation of a thin protein-resistant poly(ethylene glycol) (PEG)-based hydrogel coating for antifouling applications. The coating was fabricated by free-radical polymerization on silanized glass and silicon and on polystyrene-covered silicon and gold. The physicochemical properties of the coating were characterized by infrared spectroscopy, ellipsometry, and contact angle measurements. In particular, the chemical stability of the coating in artificial seawater was evaluated over a six-month period. These measurements indicated that the degradation process was slow under the test conditions chosen, with the coating thickness and composition changing only marginally over the period. The settlement behavior of a broad and diverse group of marine and freshwater fouling organisms was evaluated. The tested organisms were barnacle larvae (Balanus amphitrite), algal zoospores (Ulva linza), diatoms (Navicula perminuta), and three bacteria species (Cobetia marina, Marinobacter hydrocarbonoclasticus, and Pseudomonas fluorescens). The biological results showed that the hydrogel coating exhibited excellent antifouling properties with respect to settlement and removal. PMID:18759475

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

    Science.gov (United States)

    Sharma, Sadhana; Desai, Tejal A

    2005-02-01

    The creation of antifouling surfaces is one of the major prerequisites for silicon-based micro-electrical-mechanical systems for biomedical and analytical applications (known as BioMEMS). Poly(ethylene glycol) (PEG), a water-soluble, nontoxic, and nonimmunogenic polymer has the unique ability to reduce nonspecific protein adsorption and cell adhesion and, therefore, is generally coupled with a wide variety of surfaces to improve their biocompatibility. To this end, we have analyzed PEG thin films of various grafting densities (i.e., number of PEG chains per unit area) coupled to silicon using a single-step PEG-silane coupling reaction scheme using variable-angle ellipsometry. Initial PEG concentration and coupling time were varied to attain different grafting densities. These data were theoretically analyzed to understand the phenomenon of PEG film formation. Furthermore, all the PEG films were evaluated for their ability to control biofouling using albumin and fibrinogen as the model proteins. PEG thin films formed by using higher PEG concentrations ( > or = 10 mM PEG) or coupling time ( > or = 1 h) demonstrated enhanced protein fouling resistance behavior. This analysis is expected to be useful to form PEG films of desired grafting density on silicon substrates for appropriate application. PMID:15853141

  9. Using poly(ethylene glycol) silane to prevent protein adsorption in microfabricated silicon channels

    Science.gov (United States)

    Bell, Darrel J.; Brody, James P.; Yager, Paul

    1998-03-01

    Microfluidic devices fabricated in silicon are quickly finding use in many areas of technology. Exploration of new applications of this technology has shown both advantages and disadvantages to extreme miniaturization of chemical assays. While accuracy, efficiency and smaller sample volumes are among the advantages, interactions between the walls of the micro-channels and the fluid or particles it contains are among the disadvantages. Our group is applying this technology to chemical and biological warfare (CBW) agent purification and detection. We present preliminary result towards achieving a long-term antifouling surface in our detection system. A microfluidic device was anisotropically etched in a (100) silicon wafer and attached to a Pyrex glass slip to create an enclosed channel. Poly(ethylene glycol) (PEG) silane was covalently bonded to the hydroxyls of an oxide layer on the silicon device and the Pyrex cover slip. Fluorescently labeled ovalbumin, a CBW simulant, was in contact with an unmodified and PEG-modified channel. The extent of adsorption was determined using fluorescence microscopy.

  10. Grafting of poly(ethylene glycol) on click chemistry modified Si(100) surfaces.

    Science.gov (United States)

    Flavel, Benjamin S; Jasieniak, Marek; Velleman, Leonora; Ciampi, Simone; Luais, Erwann; Peterson, Joshua R; Griesser, Hans J; Shapter, Joe G; Gooding, J Justin

    2013-07-01

    Poly(ethylene glycol) (PEG) is one of the most extensively studied antifouling coatings due to its ability to reduce protein adsorption and improve biocompatibility. Although the use of PEG for antifouling coatings is well established, the stability and density of PEG layers are often inadequate to provide optimum antifouling properties. To improve on these shortcomings, we employed the stepwise construction of PEG layers onto a silicon surface. Acetylene-terminated alkyl monolayers were attached to nonoxidized crystalline silicon surfaces via a one-step hydrosilylation procedure with 1,8-nonadiyne. The acetylene-terminated surfaces were functionalized via a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction of the surface-bound alkynes with an azide to produce an amine terminated layer. The amine terminated layer was then further conjugated with PEG to produce an antifouling surface. The antifouling surface properties were investigated by testing adsorption of human serum albumin (HSA) and lysozyme (Lys) onto PEG layers from phosphate buffer solutions. Detailed characterization of protein fouling was carried out with X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) combined with principal component analysis (PCA). The results revealed no fouling of albumin onto PEG coatings whereas the smaller protein lysozyme adsorbed to a very low extent. PMID:23790067

  11. Bistable random laser that uses a phase transition of polyethylene glycol

    Science.gov (United States)

    Saito, Mitsunori; Nishimura, Yoshihiro

    2016-03-01

    Polyethylene glycol (PEG) is transparent in the liquid phase and turns to a translucent solid through a phase transition at around room temperature. A PEG solution of rhodamine 6G was excited by a laser pulse (527 nm wavelength, 10 ns duration, 190 μJ) to measure fluorescence spectra during the phase transition process. Whereas the fluorescence peak was weak and broad at 60 °C (spontaneous emission), a strong, narrow peak appeared in the temperature range below 50 °C, since a stimulated emission (amplified spontaneous emission) took place due to the scattering in the solid PEG. This laser emission control was repeatable by reversing an electric voltage (-12 or +12 V) that drove a Peltier element. Interestingly, the sample exhibited a strong stimulated emission at 52 °C during the heating process, although no strong emission was visible at the same temperature during the cooling process (bistability). The fluorescence peak wavelength was tunable between 566 and 572 nm by changing the cooling rate.

  12. Transdermal thiol-acrylate polyethylene glycol hydrogel synthesis using near infrared light.

    Science.gov (United States)

    Chung, Solchan; Lee, Hwangjae; Kim, Hyung-Seok; Kim, Min-Gon; Lee, Luke P; Lee, Jae Young

    2016-08-01

    Light-induced polymerization has been widely applied for hydrogel synthesis, which conventionally involves the use of ultraviolet or visible light to activate a photoinitiator for polymerization. However, with these light sources, transdermal gelation is not efficient and feasible due to their substantial interactions with biological systems, and thus a high power is required. In this study, we used biocompatible and tissue-penetrating near infrared (NIR) light to remotely trigger a thiol-acrylate reaction for efficient in vivo gelation with good controllability. Our gelation system includes gold nanorods as a photothermal agent, a thermal initiator, diacrylate polyethylene glycol (PEG), and thiolated PEG. Irradiation with a low-power NIR laser (0.3 W cm(-2)) could induce gelation via a mixed-mode reaction with a small increase in temperature (∼5 °C) under the optimized conditions. We also achieved successful transdermal gelation via the NIR-assisted photothermal thiol-acryl reactions. This new type of NIR-assisted thiol-acrylate polymerization provides new opportunities for in situ hydrogel formation for injectable hydrogels and delivery of drugs/cells for various biomedical applications. PMID:27389611

  13. Synthesis and Biological Evaluation of Novel Water-Soluble Poly-(ethylene glycol-10-hydroxycamptothecin Conjugates

    Directory of Open Access Journals (Sweden)

    Na Guo

    2015-05-01

    Full Text Available In order to improve the antitumor activity and water solubility of 10-hydroxycamptothecin (HCPT, a series of novel HCPT conjugates were designed and synthesized by conjugating polyethylene glycol (PEG to the 10-hydroxyl group of HCPT via a valine spacer. The in vitro stability of these synthesized compounds was determined in pH 7.4 buffer at 37 °C, and the results showed that they released HCPT at different rates. All the compounds demonstrated significant antitumor activity in vitro against K562, HepG2 and HT-29 cells. Among them, compounds, 4a, 4d, 4e and 4f, exhibited 2–5 times higher potency than HCPT. The stability and antitumor activity of these conjugates were found to be closely related to the length of PEG and the linker type, conjugates with a relatively short PEG chain and carbamate linkages (compounds 4a and 4f exhibited controlled release of HCPT and excellent antitumor in vitro activity.

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

    International Nuclear Information System (INIS)

    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.

  15. Immune cell impact of three differently coated lipid nanocapsules: pluronic, chitosan and polyethylene glycol.

    Science.gov (United States)

    Farace, Cristiano; Sánchez-Moreno, Paola; Orecchioni, Marco; Manetti, Roberto; Sgarrella, Francesco; Asara, Yolande; Peula-García, José M; Marchal, Juan A; Madeddu, Roberto; Delogu, Lucia G

    2016-01-01

    Lipid nanocapsules (NCs) represent promising tools in clinical practice for diagnosis and therapy applications. However, the NC appropriate functionalization is essential to guarantee high biocompatibility and molecule loading ability. In any medical application, the immune system-impact of differently functionalized NCs still remains to be fully understood. A comprehensive study on the action exerted on human peripheral blood mononuclear cells (PBMCs) and major immune subpopulations by three different NC coatings: pluronic, chitosan and polyethylene glycol-polylactic acid (PEG) is reported. After a deep particle characterization, the uptake was assessed by flow-cytometry and confocal microscopy, focusing then on apoptosis, necrosis and proliferation impact in T cells and monocytes. Cell functionality by cell diameter variations, different activation marker analysis and cytokine assays were performed. We demonstrated that the NCs impact on the immune cell response is strongly correlated to their coating. Pluronic-NCs were able to induce immunomodulation of innate immunity inducing monocyte activations. Immunomodulation was observed in monocytes and T lymphocytes treated with Chitosan-NCs. Conversely, PEG-NCs were completely inert. These findings are of particular value towards a pre-selection of specific NC coatings depending on biomedical purposes for pre-clinical investigations; i.e. the immune-specific action of particular NC coating can be excellent for immunotherapy applications. PMID:26728491

  16. Immune cell impact of three differently coated lipid nanocapsules: pluronic, chitosan and polyethylene glycol

    Science.gov (United States)

    Farace, Cristiano; Sánchez-Moreno, Paola; Orecchioni, Marco; Manetti, Roberto; Sgarrella, Francesco; Asara, Yolande; Peula-García, José M.; Marchal, Juan A.; Madeddu, Roberto; Delogu, Lucia G.

    2016-01-01

    Lipid nanocapsules (NCs) represent promising tools in clinical practice for diagnosis and therapy applications. However, the NC appropriate functionalization is essential to guarantee high biocompatibility and molecule loading ability. In any medical application, the immune system-impact of differently functionalized NCs still remains to be fully understood. A comprehensive study on the action exerted on human peripheral blood mononuclear cells (PBMCs) and major immune subpopulations by three different NC coatings: pluronic, chitosan and polyethylene glycol-polylactic acid (PEG) is reported. After a deep particle characterization, the uptake was assessed by flow-cytometry and confocal microscopy, focusing then on apoptosis, necrosis and proliferation impact in T cells and monocytes. Cell functionality by cell diameter variations, different activation marker analysis and cytokine assays were performed. We demonstrated that the NCs impact on the immune cell response is strongly correlated to their coating. Pluronic-NCs were able to induce immunomodulation of innate immunity inducing monocyte activations. Immunomodulation was observed in monocytes and T lymphocytes treated with Chitosan-NCs. Conversely, PEG-NCs were completely inert. These findings are of particular value towards a pre-selection of specific NC coatings depending on biomedical purposes for pre-clinical investigations; i.e. the immune-specific action of particular NC coating can be excellent for immunotherapy applications. PMID:26728491

  17. Fibrin-loaded porous poly(ethylene glycol) hydrogels as scaffold materials for vascularized tissue formation.

    Science.gov (United States)

    Jiang, Bin; Waller, Thomas M; Larson, Jeffery C; Appel, Alyssa A; Brey, Eric M

    2013-01-01

    Vascular network formation within biomaterial scaffolds is essential for the generation of properly functioning engineered tissues. In this study, a method is described for generating composite hydrogels in which porous poly(ethylene glycol) (PEG) hydrogels serve as scaffolds for mechanical and structural support, and fibrin is loaded within the pores to induce vascularized tissue formation. Porous PEG hydrogels were generated by a salt leaching technique with 100-150-μm pore size and thrombin (Tb) preloaded within the scaffold. Fibrinogen (Fg) was loaded into pores with varying concentrations and polymerized into fibrin due to the presence of Tb, with loading efficiencies ranging from 79.9% to 82.4%. Fibrin was distributed throughout the entire porous hydrogels, lasted for greater than 20 days, and increased hydrogel mechanical stiffness. A rodent subcutaneous implant model was used to evaluate the influence of fibrin loading on in vivo response. At weeks 1, 2, and 3, all hydrogels had significant tissue invasion, but no difference in the depth of invasion was found with the Fg concentration. Hydrogels with fibrin loading induced more vascularization, with a significantly higher vascular density at 20 mg/mL (week 1) and 40 mg/mL (weeks 2 and 3) Fg concentration compared to hydrogels without fibrin. In conclusion, we have developed a composite hydrogel that supports rapid vascularized tissue ingrowth, and thus holds great potential for tissue engineering applications. PMID:23003671

  18. Hydrophilicity improvement of mercerized bacterial cellulose films by polyethylene glycol graft.

    Science.gov (United States)

    da Silva, Renata; Sierakowski, Maria R; Bassani, Helen P; Zawadzki, Sônia F; Pirich, Cleverton L; Ono, Lucy; de Freitas, Rilton A

    2016-05-01

    In this work, polyethylene glycol (PEG), of tree distinct molar masses (200, 300 and 400 g mol(-1)), was grafted onto mercerized bacterial nanocellulose (BNCm) and applied to produce nanofilms (BNCm-PEG). The products BNCm-PEG were characterized by NMR and thermal analysis. Solid-state NMR and X-ray diffraction analyses exhibited no significant differences in index of BNCm-PEG derivatives compared to BNCm, indicating that grafting reaction did not modify the BNCm crystalline structure. The apparent contact angle of the films showed that BNCm-PEG films exhibited a pronounced increase in the polar components (BNCm: 8.1 mN m(-1) vs BNCm-PEG400: 29.4 mN m(-1)), and a decrease in dispersive components (BNCm: 41.7 mN m(-1) vs BNCm-PEG400: 35.2 mN m(-1)) of the surface free energy. The BNCm-PEG films were more hydrophilic than BNCm and retained the biocompatibility with L929 fibroblast cells culture. PMID:26845482

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

    Science.gov (United States)

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

    2015-05-01

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

  20. Tabletability assessment of conventional formulations containing Vitamin E tocopheryl polyethylene glycol succinate.

    Science.gov (United States)

    Jin, Feiyan; Tatavarti, Aditya

    2010-04-15

    Vitamin E tocopheryl polyethylene glycol succinate (TPGS) is known to enhance the bioavailability of poorly water-soluble drugs via solubility and permeability enhancement. Few studies have evaluated feasibility of formulating TPGS in conventional solid dosage forms such as tablets due to processing challenges resulting from its waxy nature and low melting point (approximately 37 degrees C). The objective of this study is to systematically investigate the tabletability of conventional high shear wet granulation (WG) formulations incorporated with Vitamin E TPGS. Impact of critical formulation variables such as levels of TPGS, hydroxypropyl cellulose (binder) and Prosolv (extragranular filler) on product quality attributes was studied using a full factorial experimental design. The potential influence of temperature elevation during processing was assessed through a heated die fitted onto a compaction simulator. Bilayer tabletability of the TPGS formulation was also assessed in combination with a secondary non-TPGS formulation. TPGS levels significantly impacted tensile strength (TS), disintegration time and dissolution. Heat sensitivity studies indicated that TS reduction upon exposure to heat was minimized by higher levels of extragranular fillers. Acceptable interfacial strength of bilayer tablets was achieved and tablets could be coated without the need for hydroalcoholic solutions. The study demonstrates preliminary feasibility to develop monolithic and bilayer coated tablet formulations containing up to 10% (w/w) TPGS for the given compound and drug load. Further studies are required to validate these findings at larger scales. PMID:20083178

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Directory of Open Access Journals (Sweden)

    May Lei Mei

    2016-05-01

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

  3. Inner ear delivery of dexamethasone using injectable silk-polyethylene glycol (PEG) hydrogel.

    Science.gov (United States)

    Yu, Dehong; Sun, Changling; Zheng, Zhaozhu; Wang, Xueling; Chen, Dongye; Wu, Hao; Wang, Xiaoqin; Shi, Fuxin

    2016-04-30

    Minimally invasive delivery and sustained release of therapeutics to the inner ear are of importance to the medical treatment of inner ear disease. In this study, the injectable silk fibroin-polyethylene glycol (Silk-PEG) hydrogel was investigated as a drug delivery carrier to deliver poorly soluble micronized dexamethasone (mDEX) to the inner ear of guinea pigs. Encapsulation of mDEX with a loading up to 5% (w/v) did not significantly change the silk gelation time, and mDEX were evenly distributed in the PEG-Silk hydrogel as visualized by SEM. The loading of mDEX in Silk-PEG hydrogel largely influenced in vitro drug release kinetics. The optimized Silk-PEG-mDEX hydrogel (2.5% w/v loading, in situ-forming,10μl) was administered directly onto the round window membrane of guinea pigs. The DEX concentration in perilymph maintained above 100ng/ml for at least 10 days for the Silk-PEG formulation while less than 12h for the control sample of free mDEX. Minimal systemic exposure was achieved with low DEX concentrations (scala taympani. The Silk-PEG hydrogel completely degraded in 21 days. Thus, the injectable PEG-Silk hydrogel is an effective and safe vehicle for inner ear delivery and sustained release of glucocorticoid. PMID:26972377

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

    Directory of Open Access Journals (Sweden)

    Paulo Celso Leventi Guimarães

    2013-01-01

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

  5. Polyethylene glycol (PEG)-Poly(N-isopropylacrylamide) (PNIPAAm) based thermosensitive injectable hydrogels for biomedical applications.

    Science.gov (United States)

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

    2014-11-01

    Protein and peptide delivery by the use of stimuli triggered polymers remains to be the area of interest among the scientist and innovators. In-situ forming gel for the parenteral route in the form of hydrogel and implants are being utilized for various biomedical applications. The formulation of gel depends upon factors such as temperature modulation, pH changes, the presence of ions and ultra-violet irradiation, from which drug is released in a sustained and controlled manner. Among various stimuli triggered factors, thermoresponsive is the most potential one for the delivery of protein and peptides. Poly(ethylene glycol) (PEG) based copolymers play a crucial role as a biomedical material for biomedical applications, because of its biocompatibility, biodegradability, thermosensitivity and easy controlled characters. This review, stresses on the physicochemical property, stability and compositions prospects of smart thermoresponsive polymer specifically, PEG/Poly(N-isopropylacrylamide) (PNIPAAm) based thermoresponsive injectable hydrogels, recently utilized for biomedical applications. PEG-PNIPAAm based hydrogel exhibits good gelling mechanical strength and minimizes the initial burst effect of the drug. In addition, upon changing the composition and proportion of the copolymer molecular weight and ratio, the gelling time can be reduced to a great extent providing better sol-gel transition. The hydrogel formed by the same is able to release the drug over a long duration of time, meanwhile is also biocompatible and biodegradable. Manuscript will give the new researchers an idea about the potential and benefits of PNIPAAm based thermoresponsive hydrogels for the biomedical application. PMID:25092423

  6. Docetaxel and curcumin-containing poly(ethylene glycol)-block-poly(ɛ-caprolactone) polymer micelles

    Science.gov (United States)

    Thuy Duong Le, Thi; Huyen La, Thi; Phuc Le, Thi Minh; Phuc Pham, Van; Huyen Nguyen, Thi Minh; Huan Le, Quang

    2013-06-01

    Polymeric nanoparticles (NPs) prepared from poly(ethylene glycol)-block-poly (ɛ-caprolactone) (PEG-PCL) were fabricated by the modified nanoprecipitation method with and without sonication to entrap docetaxel (Doc) and curcumin (Cur). NPs were characterized in terms of morphology, size distribution, zeta potential, encapsulation efficiency and cytotoxicity. The particles have a ˜45-80 nm mean diameter with a spherical shape. The cellular uptake of the NPs was observed after 2 and 4 h of incubation by fluorescence of curcumin loaded with docetaxel. The cell viability was evaluated by an [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay on the Hela cell line. Doc and Doc-Cur NPs had higher cytotoxicity and a much lower IC50 value compared with free Doc or Cur after 24 and 48 h of incubation. Doc and Cur incorporated into the PEG-PCL NPs had the highest cytotoxicity in comparison with all other NPs and may be considered as an attractive and promising drug delivery system for cancer treatment.

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

    Directory of Open Access Journals (Sweden)

    Hirokazu Shimoshige

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

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

    Science.gov (United States)

    Shimoshige, Hirokazu; Kobayashi, Hideki; Mizuki, Toru; Nagaoka, Yutaka; Inoue, Akira; Maekawa, Toru

    2015-01-01

    Magnetotactic bacteria (MTB) synthesize intracellular magnetic nanocrystals called magnetosomes, which are composed of either magnetite (Fe3O4) or greigite (Fe3S4) and covered with lipid membranes. The production of magnetosomes is achieved by the biomineralization process with strict control over the formation of magnetosome membrane vesicles, uptake and transport of iron ions, and synthesis of mature crystals. These magnetosomes have high potential for both biotechnological and nanotechnological applications, but it is still extremely difficult to grow MTB and produce a large amount of magnetosomes under the conventional cultural conditions. Here, we investigate as a first attempt the effect of polyethylene glycol (PEG) added to the culture medium on the increase in the yield of magnetosomes formed in Magnetospirillum magnetotacticum MS-1. We find that the yield of the formation of magnetosomes can be increased up to approximately 130 % by adding PEG200 to the culture medium. We also measure the magnetization of the magnetosomes and find that the magnetosomes possess soft ferromagnetic characteristics and the saturation mass magnetization is increased by 7 %. PMID:25993286

  9. Ultrafiltration – an alternative method to polyethylene glycol precipitation for macroprolactin detection

    Science.gov (United States)

    Beda-Maluga, Karolina; Pisarek, Hanna; Romanowska, Irena; Komorowski, Jan; Świętosławski, Jacek

    2015-01-01

    Introduction The aim of the study was to evaluate two methods of macroprolactin (MaPRL) detection – precipitation with polyethylene glycol (PEG) and ultrafiltration and to compare these techniques with “gold standard” – gel filtration chromatography (GFC). Material and methods The study was conducted on 245 patients – 45 with organic and 200 with functional hyperprolactinaemia. In all the subjects MaPRL was detected by precipitation with PEG and ultrafiltration. Additionally, gel filtration chromatography was performed in some of the serum samples. Results Macroprolactinaemia was detected in 27 patients – 8 with prolactinoma and 19 with functional hyperprolactinaemia. Assessing positive and negative results for MaPRL, we observed high diagnostic agreement (95.9%) and positive correlation (r = 0.506, p GFC in 76% of cases (all patients with functional hyperprolactinaemia). Among 6 examined patients with prolactinoma, GFC showed four false-positive results – 1 case of precipitation and 3 cases of ultrafiltration. Conclusions Efficacy of MaPRL detection with precipitation and ultrafiltration is comparable especially in cases of functional hyperprolactinaemia. In patients with prolactinoma, precipitation seems to be a more efficient separation method. PMID:26528343

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

    Science.gov (United States)

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

    2016-11-01

    Sol-gel synthesis was exploited to entrap quercetin, a natural occurring antioxidant polyphenol, in silica-based hybrid materials, which differed in their polyethylene glycol (PEG) content (6, 12, 24 and 50wt%). The materials obtained, whose nano-composite nature was ascertained by Scanning Electron Microscopy (SEM), were chemically characterized by Fourier Transform InfraRed (FT-IR) and UV-Vis spectroscopies. The results prove that a reaction between the polymer and the drug occurred. Bioactivity tests showed their ability to induce hydroxyapatite nucleation on the sample surfaces. The direct contact method was applied to screen the cytotoxicity of the synthetized materials towards fibroblast NIH 3T3 cells, commonly used for in vitro biocompatibility studies, and three nervous system cell lines (neuroblastoma SH-SY5Y, glioma U251, and pheochromocytoma PC12 cell lines), adopted as models in oxidative stress related studies. Using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay NIH 3T3 proliferation was assessed and the morphology was not compromised by direct exposure to the materials. Analogously, PC-12, and U-251 cell lines were not affected by new materials. SH-SY5Y appeared to be the most sensitive cell line with cytotoxic effects of 20-35%. PMID:27524014

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-15

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

  12. Addition of Purified Tannin Sources and Polyethylene Glycol Treatment on Methane Emission and Rumen Fermentation in Vitro

    OpenAIRE

    A. Jayanegara; H. P. S. Makkar; Becker, K

    2015-01-01

    The objectives of this experiment were (1) to observe the effects of purified tannins and polyethy-lene glycol (PEG) on in vitro rumen fermentation and methanogenesis, and (2) to assess the accuracy of volatile fatty acid (VFA) profiles in predicting methane emission. Hydrolysable and condensed tannins were extracted and purified from chestnut, sumach, mimosa and quebracho. Hay and concentrate mixture (70:30 w/w, 380 mg) was incubated in Hohenheim glass syringe containing 10 mL rumen liquor +...

  13. Seed Germination Behaviors Of Some Aerobic Rice Cultivars Oryza Sativa L After Priming With Polyethylene Glycol-8000 Peg-8000

    OpenAIRE

    Elkheir H.A; Yunus M; Muslimin M; Rinaldi Sjahril; Nurlina Kasim; Muhammad Riadi

    2015-01-01

    Seed Priming Is Famous Technique To Accelerate Seed Germination Behaviors. This Experiment Was Conducted To Study The Effect Of Polyethylene Glycol-8000 Peg-8000 As Priming Agent On Seed Germination Behavior Of Some Aerobic Rice Cultivars Oryza Sativa L. Experiment Was Carried Out By Using Two-Factor Three Aerobic Rice Cultivars And Peg With Four Replications Which Arranged In Factorial System Design And Conducted With Completely Randomized Design. The Factor Was Varieties Which Were Inpago 8...

  14. In situ measurement of humidity induced changes in the refractive index and thickness of polyethylene glycol thin films

    OpenAIRE

    Bilen, Bükem; Skarlatos, Yani; Gülen, Aktaş; İnci, Mehmet Naci; Dışpınar, Tuğba; Köse, Meliha Merve; Sanyal, Amital

    2008-01-01

    Humidity induced changes in the refractive index and thickness of polyethylene glycol (PEG) thin films are in situ determined by optical waveguide spectroscopy. PEG brushes are covalently attached to the surface of a thin gold film on a borosilicate crown glass (BK7) using a grafting-from chemical synthesis technique. The measurements are carried out in an attenuated total internal reflection setup. At low humidity levels, both the refractive index and the thickness change gradually due to sw...

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

    OpenAIRE

    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...

  16. Integrating Valve-Inspired Design Features Into Poly(ethylene glycol) Hydrogel Scaffolds For Heart Valve Tissue Engineering

    OpenAIRE

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

    2014-01-01

    The development of advanced scaffolds that recapitulate the anisotropic mechanical behavior and biological functions of the extracellular matrix in leaflets would be transformative for heart valve tissue engineering. In this study, anisotropic mechanical properties were established in poly(ethylene glycol) (PEG) hydrogels by crosslinking stripes of 3.4 kDa PEG diacrylate (PEGDA) within 20 kDa PEGDA base hydrogels using a photolithographic patterning method. Varying the stripe width and spacin...

  17. In vitro and in vivo effects of polyethylene glycol (PEG)-modified lipid in DOTAP/cholesterol-mediated gene transfection

    DEFF Research Database (Denmark)

    Gjetting, Torben; Arildsen, Nicolai Skovbjerg; Christensen, Camilla Laulund;

    2010-01-01

    DOTAP/cholesterol-based lipoplexes are successfully used for delivery of plasmid DNA in vivo especially to the lungs, although low systemic stability and circulation have been reported. To achieve the aim of discovering the best method for systemic delivery of DNA to disseminated tumors we evalua...... evaluated the potential of formulating DOTAP/cholesterol lipoplexes with a polyethylene glycol (PEG)-modified lipid, giving the benefit of the shielding and stabilizing properties of PEG in the bloodstream....

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

    OpenAIRE

    Arif Hasan Khan Robin; Md. Jasim Uddin; Khandaker Nafiz Bayazid

    2015-01-01

    Wheat is an important cereal crop worldwide that often suffers from moisture deficits at the reproductive stage. Polyethylene glycol (PEG)-treated hydroponic conditions create negative osmotic potential which is compared with moisture deficit stress. An experiment was conducted in a growth chamber to study the effects of PEG on root hair morphology and associated traits of wheat varieties. Plants of 13 wheat varieties were grown hydroponically and three different doses of PEG 6000 (w/v): 0% (...

  19. Chemical modification of recombinant interleukin 2 by polyethylene glycol increases its potency in the murine Meth A sarcoma model.

    OpenAIRE

    Katre, N V; Knauf, M J; Laird, W J

    1987-01-01

    Recombinant human interleukin 2 purified from Escherichia coli has limited solubility at neutral pH and a short circulatory half-life. This recombinant interleukin 2 was chemically modified by an active ester of polyethylene glycol. The modified interleukin 2 was purified by hydrophobic interaction chromatography and characterized by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and isoelectric focusing. This conjugate was compared to unmodified recombinant interleukin 2 in vitro ...

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

    OpenAIRE

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

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2000-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  3. Enhancement of water solubility of felodipine by preparing solid dispersion using poly-ethylene glycol 6000 and poly-vinyl alcohol

    Directory of Open Access Journals (Sweden)

    Bhole P

    2009-01-01

    Full Text Available In the present study, solid dispersion (SD of felodipine was prepared to enhance its water solubility. The SD was prepared by using polyethylene glycol (PEG 6000 and polyvinyl alcohol (PVA as a carrier with different drug polymer ratios using different techniques (physical mixing and solvent evaporation. The product was characterized by differential scanning calorimetry (DSC, X-ray diffraction (XRD and in vitro dissolution rate studies. Phase solubility analysis was performed in aqueous solution for drug polymer interactions. DSC and XRD analysis demonstrated the conversion of felodipine to amorphous form with both physical mixture (PM and SD. SD with PVA released 95% of the drug in 85 min as compared with 89% of drug released in 90 min by SD with PEG 6000. Thus, SD with both polymers increased drug release, particularly greater in the case of PVA than PEG 6000.

  4. Preparation of poly(ethylene glycol)-modified poly(amido amine) dendrimers encapsulating gold nanoparticles and their heat-generating ability.

    Science.gov (United States)

    Haba, Yasuhiro; Kojima, Chie; Harada, Atsushi; Ura, Tomoaki; Horinaka, Hiromichi; Kono, Kenji

    2007-05-01

    Loading of HAuCl4 in poly(amido amine) G4 dendrimers having poly(ethylene glycol) (PEG) grafts at all chain ends and subsequent reduction with NaBH4 yielded PEG-modified dendrimers encapsulating gold nanoparticles (Au NPs) of ca. 2 nm diameter. The Au NPs held in the dendrimers were stable in aqueous solutions and dissolved readily, even after freeze-drying. Despite their small particle size, the heat-generating ability of Au NPs held in the dendrimer was comparable to that of widely used Au NPs with ca. 11 nm diameter under visible light irradiation. The observed excellent colloidal stability, high heat-generating ability and their biocompatible surface confirm that the PEG-modified dendrimers encapsulating Au NPs are a promising tool for photothermal therapy and imaging.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    Xianhu Zhou; Chunyuan Wang; Shiqing Feng; Jin Chang; Xiaohong Kong; Yang Liu; Shijie Gao

    2012-01-01

    Naive liposomes can cross the blood-brain barrier and blood-spinal cord barrier in small amounts. Liposomes modified by a transactivating-transduction protein can deliver antibiotics for the treatment of acute bacterial infection-induced brain inflammation. Liposomes conjugated with polyethylene glycol have the capability of long-term circulation. In this study we prepared transactivating-transduction protein-polyethylene glycol-modified liposomes labeled with fluorescein isothiocyanate. Thus, liposomes were characterized by transmembrane, long-term circulation and fluorescence tracing. Uptake, cytotoxicity, and the ability of traversing blood-spinal cord and blood-brain barriers were observed following coculture with human breast adenocarcinoma cells (MCF-7). Results demonstrated that the liposomes had good biocompatibility, and low cytotoxicity when cocultured with human breast adenocarcinoma cells. Liposomes could traverse cell membranes and entered the central nervous system and neurocytes through the blood-spinal cord and blood-brain barriers of rats via the systemic circulation. These results verified that fluorescein isothiocyanate-modified transactivating-transduction protein-polyethylene glycol liposomes have the ability to traverse the blood-spinal cord and blood-brain barriers.

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

    Science.gov (United States)

    Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md. Rakibul

    2016-01-01

    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. PMID:27367738

  8. Physical properties of poly(lactic-co-glycolic) and poly(ethylene glycol) nanoparticles for drug delivery using atomic force microscopy (AFM) and electrostatic nanolithography

    Science.gov (United States)

    Lyuksyutov, Sergei; Fedin, Igor; Nedashkivska, Victoria; Lyuksyutova, Caterina; Geldenhuys, Werner; Sutariya, Vijay

    2010-03-01

    Nanoparticles (NP) of biodegradable polymers poly(lactic-co-glycolic)(PLGA) and poly(ethylene glycol) (PEG) are potential drug delivery components for biomedical applications. The NP based on PLGA or PEG can be directed to accumulate in cancer tumor cells with the use of anti-bodies which are conjugated to the NP. The NP's size distribution is the critical property for biochemical affinity and therefore delivery to the specific target organs. We used an atomic force microscopy (AFM) to characterize the NP size and AFM electrostatic nanolithography (AFMEN) to study the behavior of PEG-PLGA NP under the extreme electric fields exceeding 10^9 V m-1. AFMEN allows the displacement of molecules along the lines of the electric field due to electrostatic polarization. This study has an important practical application for the optimum design of NP with the correct characteristics for drug delivery.

  9. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Aqueous phase reforming of ethylene glycol - Role of intermediates in catalyst performance

    NARCIS (Netherlands)

    Vlieger, de D.J.M.; Mojet, B.L.; Lefferts, L.; Seshan, K.

    2012-01-01

    Liquid product formation during the aqueous catalytic reforming of ethylene glycol (EG) was studied up to 450 °C and 250 bar pressure. Methanol, ethanol, and acetic acid were the main liquid by-products during EG reforming in the presence of alumina-supported Pt and Pt–Ni catalysts. The effect of th

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

    Directory of Open Access Journals (Sweden)

    Moreshwar Pandharinath Patil

    2011-03-01

    Full Text Available The present study was initiated with the objective of studying the in vitro dissolution behavior of gliclazide from its solid dispersion with polyethylene glycol 6000. In this work, a solid dispersion of gliclazide with polyethylene glycol was prepared by the fusion method. In vitro dissolution study of gliclazide, its physical mixture and solid dispersion were carried out to demonstrate the effect of PEG 6000. Analytical techniques of FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry were used to characterize the drug in the physical mixtures and solid dispersions. The dissolution studies of solid dispersion and physical mixture showed greater improvement compared to that of the pure drug. The mechanisms for increased dissolution rate may include reduction of crystallite size, a solubilization effect of the carrier, absence of aggregation of drug crystallites, improved wettability and dispersbility of the drug from the dispersion, dissolution of the drug in the hydrophilic carrier or conversion of drug to an amorphous state. The FT-IR spectra suggested that there was no interaction between gliclazide and PEG 6000 when prepared as a solid dispersion. DSC and XRD study indicated that the drug was converted in the amorphous form.O presente trabalho foi realizado com o objetivo de estudar o comportamento in vitro da dissolução da gliclazida a partir da sua dispersão sólida com polietileno glicol 6000. Neste trabalho, as dispersões sólidas de gliclazida com polietileno glicol foram preparadas pelo método de fusão. Os estudo de dissolução in vitro da gliclazida, na mistura física e nas dispersões sólidas foram realizados para demonstrar o efeito de PEG 6000. Técnicas analíticas como espectroscopia FT-IR, calorimetria diferencial de varredura e difração de raios-X foram empregadas para caracterizar o fármaco nas misturas físicas e nas dispersoes sólidas. Os estudos de dissolução demonstraram maior

  12. Ligand conjugation to bimodal poly(ethylene glycol) brush layers on microbubbles.

    Science.gov (United States)

    Chen, Cherry C; Borden, Mark A

    2010-08-17

    Using microbubbles as model systems, we examined molecular diffusion and binding to colloidal surfaces in bimodal poly(ethylene glycol) (PEG) brush layers. A microbubble is a gaseous colloidal particle with a diameter of less than 10 mum, of which the surface comprises amphiphilic phospholipids self-assembled to form a lipid monolayer shell. Due to the compressible gas core, microbubbles provide a sensitive acoustic response and are currently used as ultrasound contrast agents. Similar to the design of long circulating liposomes, PEG chains are typically incorporated into the shell of microbubbles to form a steric barrier against coalescence and adsorption of macromolecules to the microbubble surface. We introduced a buried-ligand architecture (BLA) design where the microbubble surface was coated with a bimodal PEG brush. After microbubbles were generated, fluorescent ligands with different molecular weights were conjugated to the tethered functional groups on the shorter PEG chains, while the longer PEG chains served as a shield to protect these ligands from exposure to the surrounding environment. BLA microbubbles reduced the binding of macromolecules (>10 kDa) to the tethers due to the steric hindrance of the PEG overbrush while allowing the uninhibited attachment of small molecules (microbubbles compared to exposed-ligand architecture (ELA) microbubbles. The binding of SA-FITC to BLA microbubbles suggested a possible phase separation between the lipid species on the surface leading to populations of revealed and concealed ligands. Ligand conjugation kinetics was independent of microbubble size, regardless of ligand size or microbubble architecture. We observed, for the first time, streptavidin-induced surface structure formation for ELA microbubbles and proposed that this phenomenon may be correlated to flow cytometry scattering measurements. We therefore demonstrated the feasibility of postlabeling for small-molecule ligands to BLA microbubbles to generate

  13. Enhanced dechlorination of tetrachloroethylene by zerovalent silicon in the presence of polyethylene glycol under anoxic conditions.

    Science.gov (United States)

    Lee, Chun-Chi; Doong, Ruey-An

    2011-03-15

    The combination of zerovalent silicon (Si(0)) with polyethylene glycol (PEG) is a novel technique to enhance the dechlorination efficiency and rate of chlorinated hydrocarbons. In this study, the dechlorination of tetrachloroethylene (PCE) by Si(0) in the presence of various concentrations of PEG was investigated under anoxic conditions. Several surfactants including cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Tween 80 were also selected for comparison. Addition of SDS and Tween 80 had little effect on the enhancement of PCE dechlorination, while CTAB and PEG significantly enhanced the dechlorination efficiency and rate of PCE by Si(0) under anoxic conditions. The Langmuir-Hinshelwood model was used to describe the dechlorination kinetics of PCE and could be simplified to pseudo-first-order kinetics at low PCE concentration. The rate constants (k(obs)) for PCE dechlorination were 0.21 and 0.36 h(-1) in the presence of CTAB and PEG, respectively. However, the reaction mechanisms for CTAB and PEG are different. CTAB could enhance the apparent water solubility of PCE in solution containing Si(0), leading to the enhancement of dechlorination efficiency and rate of PCE, while PEG prevented the formation of silicon dioxide, and significantly enhanced the dechlorination efficiency and rate of PCE at pH 8.3 ± 0.2. In addition, the dechlorination rate increased upon increasing PEG concentration and then leveled off to a plateau when the PEG concentration was higher than 0.2 μM. The k(obs) for PCE dechlorination by Si(0) in the presence of PEG was 106 times higher than that by Si(0) alone. Results obtained in this study would be helpful in facilitating the development of processes that could be useful for the enhanced degradation of cocontaminants by zerovalent silicon.

  14. The Use of Polyethylene Glycol in Mammalian Herbivore Diet Studies: What Are We Measuring?

    Science.gov (United States)

    Windley, Hannah R; Wigley, Hannah J; Ruscoe, Wendy A; Foley, William J; Marsh, Karen J

    2016-06-01

    Polyethylene glycol (PEG) has been used to study the intake and digestion of tannin-rich plants by mammalian herbivores because it preferentially binds to tannins. However, it is not clear whether the responses of herbivores to dietary PEG is due to increased protein availability from the release of tannin-bound protein, amelioration of tannin effects, or whether PEG also may bind to other compounds and change their activity in the gut. We used three native New Zealand tree species to measure the effect of PEG on the amount of foliage eaten by invasive common brushtail possums (Trichosurus vulpecula) and on in vitro digestible nitrogen (available N). The addition of PEG increased the in vitro available N content of Weinmannia racemosa foliage, and possums ate significantly more PEG-treated foliage than untreated foliage. However, possums also ate more PEG-treated Fuchsia excorticata foliage, even though PEG did not increase in vitro available N in this species. Possums ate very little Melicytus ramiflorus, regardless of PEG treatment, even though M. ramiflorus contained the highest concentration of in vitro available N. These results prompted us to use PEG and a protein supplement, casein, to manipulate the available N concentration of diets containing ground eucalypt foliage, a well-studied food species for possums. Again, the response of possums to PEG was independent of changes in in vitro available N. In addition, altering the protein content of the diet via the addition of casein did not affect how much food the possums consumed. We conclude that the effects of PEG on dry matter intake by mammalian herbivores are not due solely to the release of tannin-bound protein. There is need for a better understanding of PEG-tannin interactions in order to ensure that the use of PEG in nutritional studies does not outstrip an understanding of its mechanisms of action. PMID:27256074

  15. Partitioning of alcohol ethoxylates and polyethylene glycols in the marine environment: Field samplings vs laboratory experiments

    Energy Technology Data Exchange (ETDEWEB)

    Traverso-Soto, Juan M. [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain); Brownawell, Bruce J. [School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000 (United States); González-Mazo, Eduardo [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain); Lara-Martín, Pablo A., E-mail: pablo.lara@uca.es [Departamento de Química Física, Facultad de Ciencias del Mar y Ambientales, Campus de Excelencia Internacional del Mar (CEI-MAR), Universidad de Cádiz, Campus Río San Pedro s/n, Puerto Real, Cádiz 11510 (Spain)

    2014-08-15

    Nowadays, alcohol ethoxylates (AEOs) constitute the most important group of non-ionic surfactants, used in a wide range of applications such as household cleaners and detergents. Significant amounts of these compounds and their degradation products (polyethylene glycols, PEGs, which are also used for many other applications) reach aquatic environments, and are eliminated from the water column by degradation and sorption processes. This work deals with the environmental distribution of AEOs and PEGs in the Long Island Sound Estuary, a setting impacted by sewage discharges from New York City (NYC). The distribution of target compounds in seawater was influenced by tides, consistent with salinity differences, and concentrations in suspended solid samples ranged from 1.5 to 20.5 μg/g. The more hydrophobic AEOs were mostly attached to the particulate matter whereas the more polar PEGs were predominant in the dissolved form. Later, the sorption of these chemicals was characterized in the laboratory. Experimental and environmental sorption coefficients for AEOs and PEGs showed average values from 3607 to 164,994 L/kg and from 74 to 32,862 L/kg, respectively. The sorption data were fitted to a Freundlich isotherm model with parameters n and log K{sub F} between 0.8–1.2 and 1.46–4.39 L/kg, respectively. AEO and PEG sorptions on marine sediment were also found to be mostly not affected by changes in salinity. - Highlights: • AEO and PEG levels in estuaries are influenced by tides and suspended solids. • Sediment–water partition coefficients in the lab and in the field are comparable. • Sorption is depending on both hydrophilic and hydrophobic interactions. • Sorption data fits Freundlich isotherms, showing K{sub F} values from 29 to 24,892 L/kg. • Sorption is very weakly influenced by salinity changes.

  16. Spectroscopic studies of Cr3+ ions doped in poly(vinylalcohol) complexed polyethylene glycol polymer films

    Science.gov (United States)

    Rao, T. Rajavardhana; Brahmam, K. Veera; Raju, Ch. Linga

    2015-05-01

    Polymer films of Poly(vinylalcohol) (PVA) complexed with Polyethylene glycol (PEG) with different dopant concentrations of Cr3+ ions are prepared by solution cast technique. Electron paramagnetic resonance (EPR), Optical absorption and FT-IR studies have been carried out on the polymer films. The EPR spectra of the entire samples exhibit resonance signal at g ≈1.97 which is attributed to the isolated Cr3+ pairs. The temperature variation EPR studies show that the population of spin-levels participating in the resonance decreases with an increase in temperature, which is in accordance with the Boltzmann Law. The paramagnetic susceptibilities (X) have been calculated from the EPR data at different temperatures. The linewidth of the g ≈1.97 resonance signal has been found to be decreasing with an increase in temperature, which confirms the pairing mechanism between Cr3+ ions. The Optical absorption spectrum of chromium ions in (PVA+PEG) polymer films exhibits three bands, corresponding to the d-d transitions 4A2g(F)→4T1g(F), 4A2g(F)→4T2g(F) and 4A2g(F)→2T1g(G), in the order of decreasing energy. The crystal field parameter Dq and the Racah interelectronic repulsion parameters B and C have been evaluated. From the ultraviolet absorption edges, Optical band gap (Eopt) and Urbach (ΔE) energies are evaluated. FT-IR spectrum exhibits few bands which are attributed to O-H, CH, C=C and C=O groups of stretching and bending vibrations.

  17. Thermoacoustical analysis of solutions of poly(ethylene glycol) 200 through H-bond complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Yasmin, Maimoona, E-mail: myasmin908@gmail.com [Department of Physics, University of Lucknow, Lucknow 226007 (India); Gupta, Manisha, E-mail: guptagm@rediffmail.com [Department of Physics, University of Lucknow, Lucknow 226007 (India)

    2011-05-10

    Research highlights: {yields} The presence of two electronegative elements viz. nitrogen and oxygen in its molecular architecture, ethanolamine has greater extent of interaction with PEG. {yields} Ethanolamine and m-cresol may be involved in a complex type of network of hydrogen bonding. {yields} Ethanolamine has greater extent of interaction with PEG than m-cresol and aniline particularly with least magnitude from aniline, where electron availability is least because of delocalization. {yields} The difference in molar volume between the components of the mixture control the mixture properties. - Abstract: Densities ({rho}) and ultrasonic velocities (u) of binary mixtures of poly(ethylene glycol) 200, PEG, with ethanolamine, m-cresol and aniline have been measured at various concentrations at 293.15, 303.15 and 313.15 K and have been fitted by third order polynomial equations at each temperature. The calculated values of isentropic compressibility (k{sub s}), free volume (V{sub f}), internal pressure ({pi}{sub i}), relaxation time ({tau}) and surface tension ({sigma}) at different mole fractions of PEG have been used to explain the hydrogen bonding and intermolecular interactions present in the mixture. Using these data, excess molar volume (V{sup E}), excess intermolecular free length (L{sub f}{sup E}), excess acoustic impedance (Z{sup E}) and excess pseudo-Grueneisen parameter ({Gamma}{sup E}) have been calculated and the results have been fitted to Redlich-Kister polynomial equation. All the results support each other and help in understanding the interactions in the mixture. Various models and mixing rules have been applied to evaluate the ultrasonic velocity data and have been compared with the experimental results.

  18. Antioxidant response of Stevia rebaudiana B. to polyethylene glycol and paclobutrazol treatments under in vitro culture.

    Science.gov (United States)

    Hajihashemi, Shokoofeh; Ehsanpour, Ali Akbar

    2014-04-01

    This investigation was carried out with the aim of determining the effect of paclobutrazol (PBZ) (0 and 2 mg l(-1)) and polyethylene glycol (PEG) (0, 2, 4 and 6 % w/v of PEG 6000) treatments on antioxidant system of Stevia rebaudiana Bertoni under in vitro condition. Analysis of data showed that PEG treatment significantly increased hydrogen peroxide (H2O2) and phenolic contents, while PBZ treatment limited the effect of PEG on them. Our data revealed that PEG treatment significantly increased total antioxidant capacity, catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and peroxidase (POD) activity, while it inversely decreased glutathione reductase (GR) activity. The superoxide dismutase (SOD) activity was not affected by PEG treatment. PBZ treatment induced significantly higher levels of CAT and GR activity and lower levels of SOD activity in PEG-treated plants. PBZ in combination with PEG resulted in no significant difference on APX activity with PEG treatment alone. PBZ treatment prevented the effect of PEG on the PPO activity. PEG (with or without PBZ) treatment increased the ascorbate pool, whereas total glutathione level was not affected by PEG. Our finding indicated that PBZ reduced the negative effect of PEG treatment by quenching H2O2 accumulation and increasing the CAT activity. Collectively, the antioxidant capacity of S. rebaudiana in PEG treatment condition was associated with active enzymatic and non-enzymatic defence systems which partly could be improved by the PBZ treatment. In addition, a higher accumulation of phenolic compounds leads to a more potent reactive oxygen species scavenging activity in S. rebaudiana. PMID:24604127

  19. Thermoacoustical analysis of solutions of poly(ethylene glycol) 200 through H-bond complex formation

    International Nuclear Information System (INIS)

    Research highlights: → The presence of two electronegative elements viz. nitrogen and oxygen in its molecular architecture, ethanolamine has greater extent of interaction with PEG. → Ethanolamine and m-cresol may be involved in a complex type of network of hydrogen bonding. → Ethanolamine has greater extent of interaction with PEG than m-cresol and aniline particularly with least magnitude from aniline, where electron availability is least because of delocalization. → The difference in molar volume between the components of the mixture control the mixture properties. - Abstract: Densities (ρ) and ultrasonic velocities (u) of binary mixtures of poly(ethylene glycol) 200, PEG, with ethanolamine, m-cresol and aniline have been measured at various concentrations at 293.15, 303.15 and 313.15 K and have been fitted by third order polynomial equations at each temperature. The calculated values of isentropic compressibility (ks), free volume (Vf), internal pressure (πi), relaxation time (τ) and surface tension (σ) at different mole fractions of PEG have been used to explain the hydrogen bonding and intermolecular interactions present in the mixture. Using these data, excess molar volume (VE), excess intermolecular free length (LfE), excess acoustic impedance (ZE) and excess pseudo-Grueneisen parameter (ΓE) have been calculated and the results have been fitted to Redlich-Kister polynomial equation. All the results support each other and help in understanding the interactions in the mixture. Various models and mixing rules have been applied to evaluate the ultrasonic velocity data and have been compared with the experimental results.

  20. Development of poly(ethylene glycol) hydrogels for salivary gland tissue engineering applications.

    Science.gov (United States)

    Shubin, Andrew D; Felong, Timothy J; Graunke, Dean; Ovitt, Catherine E; Benoit, Danielle S W

    2015-06-01

    More than 40,000 patients are diagnosed with head and neck cancers annually in the United States with the vast majority receiving radiation therapy. Salivary glands are irreparably damaged by radiation therapy resulting in xerostomia, which severely affects patient quality of life. Cell-based therapies have shown some promise in mouse models of radiation-induced xerostomia, but they suffer from insufficient and inconsistent gland regeneration and accompanying secretory function. To aid in the development of regenerative therapies, poly(ethylene glycol) hydrogels were investigated for the encapsulation of primary submandibular gland (SMG) cells for tissue engineering applications. Different methods of hydrogel formation and cell preparation were examined to identify cytocompatible encapsulation conditions for SMG cells. Cell viability was much higher after thiol-ene polymerizations compared with conventional methacrylate polymerizations due to reduced membrane peroxidation and intracellular reactive oxygen species formation. In addition, the formation of multicellular microspheres before encapsulation maximized cell-cell contacts and increased viability of SMG cells over 14-day culture periods. Thiol-ene hydrogel-encapsulated microspheres also promoted SMG proliferation. Lineage tracing was employed to determine the cellular composition of hydrogel-encapsulated microspheres using markers for acinar (Mist1) and duct (Keratin5) cells. Our findings indicate that both acinar and duct cell phenotypes are present throughout the 14 day culture period. However, the acinar:duct cell ratios are reduced over time, likely due to duct cell proliferation. Altogether, permissive encapsulation methods for primary SMG cells have been identified that promote cell viability, proliferation, and maintenance of differentiated salivary gland cell phenotypes, which allows for translation of this approach for salivary gland tissue engineering applications.

  1. Characterization of nephritogenic IgA immune complexes separated by polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Bioprinting vessel-like constructs using hyaluronan hydrogels crosslinked with tetrahedral polyethylene glycol tetracrylates.

    Science.gov (United States)

    Skardal, Aleksander; Zhang, Jianxing; Prestwich, Glenn D

    2010-08-01

    Bioprinting enables deposition of cells and biomaterials into spatial orientations and complexities that mirror physiologically relevant geometries. To facilitate the development of bioartificial vessel-like grafts, two four-armed polyethylene glycol (PEG) derivatives with different PEG chain lengths, TetraPEG8 and TetraPEG13, were synthesized from tetrahedral pentaerythritol derivatives. The TetraPEGs are unique multi-armed PEGs with a compact and symmetrical core. The TetraPEGs were converted to tetra-acrylate derivatives (TetraPAcs) which were used in turn to co-crosslink thiolated hyaluronic acid and gelatin derivatives into extrudable hydrogels for printing tissue constructs. First, the hydrogels produced by TetraPAc crosslinking showed significantly higher shear storage moduli when compared to PEG diacrylate (PEGDA)-crosslinked synthetic extracellular matrices (sECMs) of similar composition. These stiffer hydrogels have rheological properties more suited to bioprinting high-density cell suspensions. Second, TetraPAc-crosslinked sECMs were equivalent or superior to PEGDA-crosslinked gels in supporting cell growth and proliferation. Third, the TetraPac sECMs were employed in a proof-of-concept experiment by encapsulation of NIH 3T3 cells in sausage-like hydrogel macrofilaments. These macrofilaments were then printed into tubular tissue constructs by layer-by-layer deposition using the Fab@Home printing system. LIVE/DEAD viability/cytotoxicity-stained cross-sectional images showed the bioprinted cell structures to be viable in culture for up to 4 weeks with little evidence of cell death. Thus, biofabrication of cell suspensions in TetraPAc sECMs demonstrates the feasibility of building bioartificial blood vessel-like constructs for research and potentially clinical uses. PMID:20546891

  3. Determination of Trace Protein by Methylene Blue-Tetraphenylborate Fluorescence Probe Using Polyethylene Glycol as Sensitizer

    Institute of Scientific and Technical Information of China (English)

    LIU Jiaming; LI Zhiming; HUANG Xiaomei; ZENG Liqing; CHEN Xiaohua; SONG Dongqin; ZHENG Zhenzhen

    2009-01-01

    An ionic association complex of methylene blue-tetraphenyiborate ([MB]+·[B(C6H5)4]-) can emit a strong and stable fluorescence in KH2PO4-Na2HPO4 buffer solution. In the presence of bovine serum albumin (BSA), the fluo-rescence signal of [MB]+·[B(C6H5)4]- can be sharply quenched, which can be further quenched by using polyeth-ylene glycol (PEG) as a sensitizer where the △F (△F=F0-F, F0 and F are the fluorescence intensities of the blank reagent and the test solution, respectively) of the system with PEG is 9.1 times higher than that without PEG, showing PEG has strong sensitizing effect on the quenching of a fluorescence signal. And there is a good linear correlation between △F and the content of BSA. Thus, a new fluorescence probe for the determination of trace pro-tein has been established, with the linear range of 0.11-88.0 pg·L-1 and the detection limit of 22.0 ag·mL-1 BSA. This sensitive method has been applied to the determination of protein in human serum samples with satisfactory results. And the reaction mechanism was also discussed. Under the same condition, the new method can be used to determie not only BSA, human serum albumin (HAS), ovalbumin (OVA) and γ-globulin (γ-G), respectively, but also the total protein in serum, brain and spinal cord.

  4. Antioxidant response of Stevia rebaudiana B. to polyethylene glycol and paclobutrazol treatments under in vitro culture.

    Science.gov (United States)

    Hajihashemi, Shokoofeh; Ehsanpour, Ali Akbar

    2014-04-01

    This investigation was carried out with the aim of determining the effect of paclobutrazol (PBZ) (0 and 2 mg l(-1)) and polyethylene glycol (PEG) (0, 2, 4 and 6 % w/v of PEG 6000) treatments on antioxidant system of Stevia rebaudiana Bertoni under in vitro condition. Analysis of data showed that PEG treatment significantly increased hydrogen peroxide (H2O2) and phenolic contents, while PBZ treatment limited the effect of PEG on them. Our data revealed that PEG treatment significantly increased total antioxidant capacity, catalase (CAT), ascorbate peroxidase (APX), polyphenol oxidase (PPO) and peroxidase (POD) activity, while it inversely decreased glutathione reductase (GR) activity. The superoxide dismutase (SOD) activity was not affected by PEG treatment. PBZ treatment induced significantly higher levels of CAT and GR activity and lower levels of SOD activity in PEG-treated plants. PBZ in combination with PEG resulted in no significant difference on APX activity with PEG treatment alone. PBZ treatment prevented the effect of PEG on the PPO activity. PEG (with or without PBZ) treatment increased the ascorbate pool, whereas total glutathione level was not affected by PEG. Our finding indicated that PBZ reduced the negative effect of PEG treatment by quenching H2O2 accumulation and increasing the CAT activity. Collectively, the antioxidant capacity of S. rebaudiana in PEG treatment condition was associated with active enzymatic and non-enzymatic defence systems which partly could be improved by the PBZ treatment. In addition, a higher accumulation of phenolic compounds leads to a more potent reactive oxygen species scavenging activity in S. rebaudiana.

  5. Polyethylene glycols: An effective strategy for limiting liver ischemia reperfusion injury.

    Science.gov (United States)

    Pasut, Gianfranco; Panisello, Arnau; Folch-Puy, Emma; Lopez, Alexandre; Castro-Benítez, Carlos; Calvo, Maria; Carbonell, Teresa; García-Gil, Agustín; Adam, René; Roselló-Catafau, Joan

    2016-07-28

    Liver ischemia-reperfusion injury (IRI) is an inherent feature of liver surgery and liver transplantation in which damage to a hypoxic organ (ischemia) is exacerbated following the return of oxygen delivery (reperfusion). IRI is a major cause of primary non-function after transplantation and may lead to graft rejection, regardless of immunological considerations. The immediate response involves the disruption of cellular mitochondrial oxidative phosphorylation and the accumulation of metabolic intermediates during the ischemic period, and oxidative stress during blood flow restoration. Moreover, a complex cascade of inflammatory mediators is generated during reperfusion, contributing to the extension of the damage and finally to organ failure. A variety of pharmacological interventions (antioxidants, anti-cytokines, etc.) have been proposed to alleviate graft injury but their usefulness is limited by the local and specific action of the drugs and by their potential undesirable toxic effects. Polyethylene glycols (PEGs), which are non-toxic water-soluble compounds approved by the FDA, have been widely used as a vehicle or a base in food, cosmetics and pharmaceuticals, and also as adjuvants for ameliorating drug pharmacokinetics. Some PEGs are also currently used as additives in organ preservation solutions prior to transplantation in order to limit the damage associated with cold ischemia reperfusion. More recently, the administration of PEGs of different molecular weights by intravenous injection has emerged as a new therapeutic tool to protect liver grafts from IRI. In this review, we summarize the current knowledge concerning the use of PEGs as a useful target for limiting liver IRI. PMID:27605884

  6. Thermal and rheological properties of L-polylactide/polyethylene glycol/silicate nanocomposites films.

    Science.gov (United States)

    Ahmed, Jasim; Varshney, Sunil K; Auras, Rafael; Hwang, Sung W

    2010-10-01

    The melt rheology and thermal properties of polylactide (PLA)-based nanocomposite films that were prepared by solvent casting method with L-PLA, polyethylene glycol (PEG), and montmorillonite clay were studied. The neat PLA showed predominantly solid-like behavior (G' > G″) and the complex viscosity (η*) decreased systematically as the temperature increased from 184 to 196 °C. The elastic modulus (G') of PLA/clay blend showed a significant improvement in the magnitude in the melt, while clay concentration was at 6% wt or higher. At similar condition, PEG dramatically reduced dynamic modulii and complex viscosity of PLA/PEG blend as function of concentration. A nanocomposite blend of PLA/PEG/clay (74/20/6) when compared to the neat polymer and PLA/PEG blend exhibited intermediate values of elastic modulus (G') and complex viscosity (η*) with excellent flexibility. Thermal analysis of different clay loading blends indicated that the melting temperature (T(m)) and glass transition temperature (T(g)) remained unaffected irrespective of clay concentration due to immobilization of polymer chain in the clay nanocomposite. PEG incorporation reduced the T(g) and the T(m) of the blends (PLA/PEG and PLA/PEG/clay) significantly, however, crystallinity increased in the similar condition. The transmission electron microscopy (TEM) image of nanocomposite films indicated good compatibility between PLA and PEG, whereas clay was not thoroughly distributed in the PLA matrix and remained as clusters. The percent crystallinity obtained by X-ray was significantly higher than that of differential scanning calorimeter (DSC) data for PLA. PMID:21535511

  7. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava.

    Science.gov (United States)

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-01-01

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment.

  8. The Effect of Melatonin Adsorbed to Polyethylene Glycol Microspheres on the Survival of MCF-7 Cells.

    Science.gov (United States)

    França, Eduardo Luzía; Honorio-França, Adenilda Cristina; Fernandes, Rubian Trindade da Silva; Marins, Camila Moreira Ferreira; Pereira, Claudia Cristina de Souza; Varotti, Fernando de Pilla

    2016-01-01

    Although melatonin exhibits oncostatic properties such as antiproliferative effects, the oral bioavailability of this hormone is less than 20%. Modified drug release systems have been used to improve the pharmacological efficiency of drugs. These systems can change the pharmacokinetics and biodistribution of the associated drugs. Thus, this study investigated the effect of melatonin adsorbed to polyethylene glycol (PEG) microspheres on MCF-7 human breast cancer cells. The MCF-7 cells were obtained from the American Type Culture Collection. MCF-7 cells were preincubated for 24 h with or without melatonin (100 ng/ml), PEG microspheres or melatonin adsorbed to PEG microspheres (100 ng/ml). Viability, intracellular calcium release and apoptosis in MCF-7 cells were determined by flow cytometry. MCF-7 cells incubated with melatonin adsorbed to PEG microspheres showed a lower viability rate (40.0 ± 8.3 with melatonin adsorbed to PEG microspheres compared to 54.1 ± 7.3 with melatonin; 81.8 ± 12.5 with PEG microsphere and 92.7 ± 4.1 with medium), increased spontaneous intracellular Ca2+ release (27.0 ± 8.6 with melatonin adsorbed to PEG microspheres compared to 21.5 ± 13.4 with melatonin; 10.1 ± 5.4 with PEG microsphere and 9.1 ± 5.6 with medium) and increased apoptosis index (51.2 ± 2.7 with melatonin adsorbed to PEG microspheres compared to 36.0 ± 2.1 with melatonin; 4.9 ± 0.5 with PEG microsphere and 3.1 ± 0.6 with medium). The results indicate that melatonin adsorbed to PEG microspheres exerts antitumor effects on human MCF-7 breast cancer cells. However, clinical tests must be performed to confirm the use of melatonin adsorbed to PEG microspheres as an alternative therapy against cancer. PMID:26445481

  9. Polyethylene Glycol-Mediated Synthesis of Cubic Iron Oxide Nanoparticles with High Heating Power

    Science.gov (United States)

    Iacovita, Cristian; Stiufiuc, Rares; Radu, Teodora; Florea, Adrian; Stiufiuc, Gabriela; Dutu, Alina; Mican, Sever; Tetean, Romulus; Lucaciu, Constantin M.

    2015-10-01

    Iron oxide magnetic nanoparticles (IOMNPs) have been successfully synthesized by means of solvothermal reduction method employing polyethylene glycol (PEG200) as a solvent. The as-synthesized IOMNPs are poly-dispersed, highly crystalline, and exhibit a cubic shape. The size of IOMNPs is strongly dependent on the reaction time and the ration between the amount of magnetic precursor and PEG200 used in the synthesis method. At low magnetic precursor/PEG200 ratio, the cubic IOMNPs coexist with polyhedral IOMNPs. The structure and morphology of the IOMNPs were thoroughly investigated by using a wide range of techniques: TEM, XRD, XPS, FTIR, and RAMAN. XPS analysis showed that the IOMNPs comprise a crystalline magnetite core bearing on the outer surface functional groups from PEG200 and acetate. The presence of physisorbed PEG200 on the IOMNP surface is faintly detected through FT-IR spectroscopy. The surface of IOMNPs undergoes oxidation into maghemite as proven by RAMAN spectroscopy and the occurrence of satellite peaks in the Fe2p XP spectra. The magnetic studies performed on powder show that the blocking temperature (TB) of IOMNPs is around 300 K displaying a coercive field in between 160 and 170 Oe. Below the TB, the field-cooled (FC) curves turn concave and describe a plateau indicating that strong magnetic dipole-dipole interactions are manifested in between IOMNPs. The specific absorption rate (SAR) values increase with decreasing nanoparticle concentrations for the IOMNPs dispersed in water. The SAR dependence on the applied magnetic field, studied up to magnetic field amplitude of 60 kA/m, presents a sigmoid shape with saturation values up to 1700 W/g. By dispersing the IOMNPs in PEG600 (liquid) and PEG1000 (solid), it was found that the SAR values decrease by 50 or 75 %, indicating that the Brownian friction within the solvent was the main contributor to the heating power of IOMNPs.

  10. Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava.

    Science.gov (United States)

    Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

    2016-01-01

    Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment. PMID:26927071

  11. Drag reduction by polyethylene glycol in the tail arterial bed of normotensive and hypertensive rats

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

  13. Degradation of fipronil (Termidor) in aqueous solution stored in polyethylene tanks exposed to sunlight or shade.

    Science.gov (United States)

    Husen, T J; Spomer, N A; Kamble, S T

    2009-05-01

    Pest Management Professionals commonly use polyethylene or fiberglass tanks for mixing and applying termiticides. We investigated the stability of fipronil (Termidor SC) (0.06%, 0.09% and 0.125% active ingredient) in aqueous solutions stored in polyethylene tanks under sun and shade for 2 week. Chemical analysis of tank-mixed solutions sampled at 0, 24, 48, 72, 168 and 336 h indicated that fipronil remained stable. Our data indicated that polyethylene tanks prevent fipronil from photodegradation and these tanks can be safely used for short term storage (up to 2 week) of liquid termiticides.

  14. The study of The study of the influence of temperature on surfactants – polyethylene glycol layers The study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface liquid-gas interfacethe influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interfaceThe study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface

    Directory of Open Access Journals (Sweden)

    Seryk Boloshaan

    2015-03-01

    Full Text Available The surface tension of compositions consisting of nonionic polyethylene glycol and surface active substances of different nature and influence of temperatures on properties of their adsorption layers were studied. To be taken into account the basics of classical chemical thermodynamics and colloidal chemistry, the thermodynamic parameters were determined for the adsorption of glycol, cetyl pyridinium bromide, Tween- 80 and sodium dodecyl sulfate. Adsorption speed was valuated By Kinetic curves of a liquid /gas interfaces. As a surfactants were taken the anionic surfactant – sodium dodecylsulphate, cationic surfactant cetylpyridinium bromide and nonionic Tween-80. The reason of using nonionic polyethyleneglycol as polymer is that the polymer is not toxic, biodegradable and it has no harm to the human body. That is why they are largely used in food industry, pharmaceutics, cosmetics and household chemical products.

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

    Indian Academy of Sciences (India)

    Mohammad Ali Semsarzadeh; Sahar Amiri

    2013-11-01

    –Cyclodextrin (-CD) was found to form inclusion complexes with poly(ethylene glycol) (PEG) having a crystalline state in high yields, which have been investigated extensively in the past. Formation of an inclusion complex depends strongly on structure, molecular weight and geometry of the polymer. Development of a dicomponent inclusion complex (DIC) of PEG and -CD in the presence of poly(vinyl alcohol) (PVA) and initiation of hexagonal crystals upon sonication have exhibited various microstructures. Formation of the new inclusion complex in PVA heavily depends on the concentration of PVA, temperature and sonication time. The complexes produced are characterized by FTIR, HNMR spectra and powder X-ray. 1HNMR of the complexes demonstrate that their stoichiometric ratio is 2:1 (two ethylene glycol units and one -CD). X-ray patterns of PEG–-CD complex indicate that the -CD forms channels whereas PEG/-CD/PVA creates cage-type structures.

  16. Photocurable surgical tissue adhesive glues composed of photoreactive gelatin and poly(ethylene glycol) diacrylate.

    Science.gov (United States)

    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

  17. Mechanical properties of polyurethane film exposed to solutions of nonoxynol-9 surfactant and polyethylene glycol

    Science.gov (United States)

    McDermott, Martin Kendrick

    Changes in physical properties (tensile strength, strain to failure, elastic modulus, diffusion kinetics and soft segment glass transition temperature (Tg)) were examined for polyetherurethane block copolymers Estane and Tecoflex. These polymer chains consist of 2 mutually incompatible blocks or segments which form microphases consisting of rigid/hard segments in an elastomeric matrix of soft segments. The polyurethanes were exposed to mixtures of nonoxynol 9 (N9) surfactant in polyethylene glycol 400 (PEG) at various concentrations and for various times. The purpose was to estimate the effect of exposure to mixtures of N9 spermicide and PEG lubricant on breakage of condoms made from films of these elastomers. Mechanical properties of Estane varied with direction because of molecular orientation induced during manufacturing, suggesting that condoms should be cut from the film in a way that optimizes this property-orientation relationship. Large amounts of N9 were absorbed from N9/PEG solutions. The polymer fraction of the swollen Estane film versus soak solution composition did not follow a linear rule of mixtures. As the percentage of N9 in the PEG/N9 soak solution increased, Estane absorbed more liquid and its properties decreased more than did Tecoflex. This may not matter for low concentrations of N9 where the mechanical properties of Estane were superior to those of Tecoflex. The loss of mechanical properties with increased N9 concentration was likely due to plasticization of the soft segment domains. Hard segment domain disruption was probably not occurring because the relationship between the elastic modulus and polymer volume fraction followed the Flory-Rehner relationship for swollen elastic rubber networks and diffusion of neat N9 and neat PEG followed a Fickian behavior. This is expected because hard domains are much more difficult to disrupt due to strong hydrogen bonding and/or crystallization. Most of the absorption and decrease in mechanical

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

    Institute of Scientific and Technical Information of China (English)

    Kai-Lin Hwang; William Tzu-Liang Chen; Koung-Hong Hsiao; Hong-Chang Chen; Ting-Ming Huang; Chien-Ming Chiu; Ger-Haur Hsu

    2005-01-01

    AIM: To compare the effectiveness, patient acceptability, and physical tolerability of two oral lavage solutions prior to colonoscopy in a Taiwanese population. METHODS: Eighty consecutive patients were randomized to receive either standard 4 L of polyethylene glycol (PEG) or 90 mL of sodium phosphate (NaP) in a split regimen of two 45 mL doses separated by 12 h, prior to colonoscopic evaluation. The primary endpoint was the percent of subjects who had completed the preparation. Secondary endpoints included colonic cleansing evaluated with an overall assessment and segmental evaluation, the tolerance and acceptability assessed by a selfadministered structured questionnaire, and a safety profile such as any unexpected adverse events, electrolyte tests, physical exams, vital signs, and body weights. RESULTS: A significantly higher completion rate was found in the NaP group compared to the PEG group(84.2% vs 27.5%, P<0.001). The amount of fluid suctioned was significantly less in patients taking NaP vs PEG (50.13±54.8 cc vs 121.13±115.4 cc, P<0.001),even after controlling for completion of the oral solution(P = 0.031). The two groups showed a comparable overall assessment of bowel preparation with a rate of "good" or "excellent" in 78.9% of patients in the NaPgroup and 82.5% in PEG group (P = 0.778). Patients taking NaP tended to have significantly better colonic segmental cleansing relative to stool amount observedin the descending (94.7% vs 70%, P = 0.007) andtransverse (94.6% vs 74.4%, P = 0.025) colon. Slightly more patients graded the taste of NaP as "good" or "very good" compared to the PEG patients (32.5% vs 12.5%;P = 0.059). Patients' willingness to take the same preparation in the future was 68.4% in the NaP compared to 75% in the PEG group (P = 0.617). There was a significant increase in serum sodium and a significant decrease in phosphate and chloride levels in NaP group on the day following the colonoscopy without any clinical sequelae. Prolonged (

  19. Insertion stability of poly(ethylene glycol)-cholesteryl-based lipid anchors in liposome membranes.

    Science.gov (United States)

    Molnar, Daniel; Linders, Jürgen; Mayer, Christian; Schubert, Rolf

    2016-06-01

    Liposomes consist of a hydrophilic core surrounded by a phospholipid (PL) bilayer. In human blood, the half-life of such artificial vesicles is limited. To prolong their stability in the circulation, liposomal bilayers can be modified by inserting poly(ethylene glycol) (PEG) molecules using either PL or sterols as membrane anchors. This establishes a hydrophilic steric barrier, reducing the adsorption of serum proteins, recognition and elimination by cells of the immune system. In addition, targeting ligands (such as antibodies) are frequently coupled to the distal end of the PEG chains to direct the vesicles (then called 'immuno-liposomes') to specific cell types, such as tumor cells. To our knowledge, experiments on the stability of ligand anchoring have so far only been conducted with PL-based PEGs and not with sterol-based PEGs after insertion via the sterol-based post-insertion technique (SPIT). Therefore, our study examines the insertion stability of PEG-cholesteryl ester (Chol-PEG) molecules with PEG chains of 1000, 1500 and 2000Da molecular mass which have been inserted into the membranes of liposomes using SPIT. For this study we used different acceptor media and multiple analytical techniques, including pulsed-field-gradient nuclear magnetic resonance (PFG-NMR), free-flow electrophoresis, size exclusion chromatography and ultracentrifugation. The obtained data consistently showed that a higher molar mass of PEG chains positively correlates with higher release from the liposome membranes. Furthermore, we could detect and quantify the migration of Chol-PEG molecules from radioactively double-labeled surface-modified liposomes to negatively charged acceptor liposomes via free-flow electrophoresis. Insertion of Chol-PEG molecules into the membrane of preformed liposomes using SPIT is an essential step for the functionalization of liposomes with the aim of specific targeting. For the first time, we present a kinetic analysis of this insertion process using PFG

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

    International Nuclear Information System (INIS)

    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

  1. Mechanical evaluation of newly developed mouthpiece using polyethylene terephthalate glycol for transoral robotic surgery.

    Science.gov (United States)

    Fujiwara, Kazunori; Fukuhara, Takahiro; Niimi, Koji; Sato, Takahiro; Kataoka, Hideyuki; Kitano, Hiroya; Takeuchi, Hiromi

    2015-12-01

    Transoral robotic surgery (TORS), performed with the da Vinci surgical system (da Vinci), has been classified as a surgical approach for benign and malignant lesions of the oral cavity and laryngopharynx. It provides several unique advantages, which include a three-dimensional magnified view, ability to see and work around curves or angles, and the availability of two or three robotic arms. At present, however, the da Vinci surgical system does not provide haptic feedback. The potential risks specific to the transoral use of the da Vinci include tooth injury, mucosal laceration, ocular injury, and mandibular fracture. To prevent such intra-operative tooth injuries, we created a mouthpiece made of polyethylene terephthalate glycol (PETG) individually shaped for the patient's teeth. We compared the safety and efficacy of the PETG mouthpiece with those of a conventional mouthpiece made of ethylene-vinyl acetate (EVA). To determine the difference in tooth injury resulting from the two types of mouthpiece, we constructed an experimental system to measure load and strain. We measured the dynamic load and the strain from the rod to the tooth using the PETG and EVA mouthpiece. The rod was pressed against the tooth model outfitted with two types of mouthpiece and the dynamic load was measured with a load cell and the strain with a strain gage. The maximum dynamic load was 1.29 ± 0.03 kgf for the PETG mouthpiece and 2.24 ± 0.05 kgf for the EVA mouthpiece. The load against the tooth was thus less for the EVA mouthpiece. The strain was -166.84 ± 3.94 and 48.24 ± 7.77 με, respectively, while the load direction was parallel to that of the tooth axis for the PETG mouthpiece and perpendicular to the tooth axis for the EVA mouthpiece. The PETG mouthpiece reduced the tooth load compared with the EVA mouthpiece and the load direction was in parallel to the tooth axis. The PETG mouthpiece thus enhances tooth safety for TORS. PMID:26530849

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

    DEFF Research Database (Denmark)

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

    2006-01-01

    The dependence of the surface morphology on the substrate temperature during film deposition was investigated for polyethylene glycol (PEG) films by matrix-assisted pulsed laser evaporation (MAPLE). The surface structure was studied with a combined technique of optical imaging and AFM measurements....... There was a clear difference between the films produced below and above the melting point of PEG. For temperatures above the melting point, the polymer material was distributed non-uniformly over the substrate with growths areas, where cluster-like structures merge into large islands of micrometer size...

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    Matrix assisted pulsed laser evaporation (MAPLE) has been applied for deposition of thin polyethylene glycol (PEG) films with infrared laser light at 1064 nm. We have irradiated frozen targets (of 1 wt.% PEG dissolved in water) and measured the deposition rate in situ with a quartz crystal 2...... microbalance. The laser fluence needed to produce PEG films turned out to be unexpectedly high with a threshold of 9 J/cm(2) and the deposition rate was much lower than that with laser light at 355 nm. Results from matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI...

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

    OpenAIRE

    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...

  5. Deactivation of tannins in raisin stalk by polyethylene glycol-6000 effect onfeed intake, digestibility, and nitrogen retention in sheep

    OpenAIRE

    SOURI, MANOCHER; ANGAJI, LALEH; MOEINI, MOHAMMAD MEHDI

    2015-01-01

    An experiment was conducted to assess the effects of polyethylene glycol (PEG-6000) and urea on feed intake, nitrogen retention, and nutrient digestibility in sheep fed raisin stalk. Sixteen male fat-tailed Sanjabi sheep (26 ± 0.66 kg) were randomly assigned to one of 4 dietary treatments: raisin stalk (control; RS), raisin stalk supplemented with 3% urea and 4% molasses (RSU3%); 5% urea and 7% molasses (RSU5%); or 5% urea, 7% molasses plus 5% PEG (RSU-PEG) per DM of raisin stalk. The urea an...

  6. Synthesis of Monodispersed Gold Nanoparticles with Exceptional Colloidal Stability with Grafted Polyethylene Glycol-g-polyvinyl Alcohol

    Directory of Open Access Journals (Sweden)

    Alaaldin M. Alkilany

    2015-01-01

    Full Text Available Herein, we report the synthesis of spherical gold nanoparticles with tunable core size (23–79 nm in the presence of polyethylene glycol-g-polyvinyl alcohol (PEG-g-PVA grafted copolymer as a reducing, capping, and stabilizing agent in a one-step protocol. The resulted PEG-g-PVA-capped gold nanoparticles are monodispersed with an exceptional colloidal stability against salt addition, repeated centrifugation, and extensive dialysis. The effect of various synthesis parameters and the kinetic/mechanism of the nanoparticle formation are discussed.

  7. Enhanced oral absorption and therapeutic effect of acetylpuerarin based on D-α-tocopheryl polyethylene glycol 1000 succinate nanoemulsions

    Directory of Open Access Journals (Sweden)

    Sun DQ

    2014-07-01

    Full Text Available Deqing Sun,1,2 Xinbing Wei,1 Xia Xue,2 Zengjun Fang,3 Manru Ren,1 Haiyan Lou,1 Xiumei Zhang11Department of Pharmacology, School of Medicine, Shandong University, Jinan, People’s Republic of China; 2Department of Pharmacy, 3Department of Clinical Pharmacology, Second Hospital of Shandong University, Jinan, People’s Republic of ChinaBackground: Acetylpuerarin (AP, because of its lower water solubility, shows poor absorption that hinders its therapeutic application. Thus, the aim of this study was to prepare nanoemulsions for AP, enhance its oral bioavailability, and thus improve the therapeutic effect.Methods: The nanoemulsions stabilized by D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS were prepared by high-pressure homogenization and characterized in terms of particle size, drug loading, morphology, and in vitro drug release. A lipid digestion model was used to predict in vivo drug solubilization in the gastrointestinal environment. The pharmacokinetics of AP formulations were performed in rats; meanwhile, a chylomicron flow-blocking rat model was used to evaluate the lymphatic drug transport. Moreover, the therapeutic effects of AP nanoemulsions on the model of focal cerebral ischemia-reperfusion for brain injury were also assessed.Results: The nanoemulsions with a droplet size of 150 nm were well stabilized by TPGS and showed a high loading capacity for AP. In the digestion model, the distribution of AP in aqueous phase/pellet phase was about 90%/10% for nanoemulsions and 5%/95% for oil solution, indicating that the drug encapsulated in nanoemulsions would present in solubilized form after transportation into the gastrointestinal tract, whereas drug precipitation would occur as the oil solution was orally administered. The area under the curve value of AP nanoemulsions was 5.76±0.56 µg·hour·mL-1, or was about 2.6 and 1.7 times as great as that of suspension and oil solution, respectively, indicating enhanced drug

  8. Control of the saturation temperature in magnetic heating by using polyethylene-glycol-coated rod-shaped nickel-ferrite (NiFe2O4) nanoparticles

    Science.gov (United States)

    Iqbal, Yousaf; Bae, Hongsub; Rhee, Ilsu; Hong, Sungwook

    2016-02-01

    Polyethylene-glycol (PEG)-coated nickel-ferrite nanoparticles were prepared for magnetic hyperthermia applications by using the co-precipitation method. The PEG coating occurred during the synthesis of the nanoparticles. The coated nanoparticles were rod-shaped with an average length of 16 nm and an average diameter of 4.5 nm, as observed using transmission electron microscopy. The PEG coating on the surfaces of the nanoparticles was confirmed from the Fourier-transform infrared spectra. The nanoparticles exhibited superparamagnetic characteristics with negligible coercive force. Further, magnetic heating effects were observed in aqueous solutions of the coated nanoparticles. The saturation temperature could be controlled at 42 ℃ by changing the concentration of the nanoparticles in the aqueous solution. Alternately, the saturation temperature could be controlled for a given concentration of nanoparticles by changing the intensity of the magnetic field. The Curie temperature of the nanoparticles was estimated to be 495 ℃. These results for the PEG-coated nickel-ferrite nanoparticles showed the possibility of utilizing them for controlled magnetic hyperthermia at 42 ℃.

  9. Formulation of polylactide-co-glycolic acid nanospheres for encapsulation and sustained release of poly(ethylene imine-poly(ethylene glycol copolymers complexed to oligonucleotides

    Directory of Open Access Journals (Sweden)

    Wheatley Margaret A

    2009-04-01

    Full Text Available Abstract Antisense oligonucleotides (AOs have been shown to induce dystrophin expression in muscles cells of patients with Duchenne Muscular Dystrophy (DMD and in the mdx mouse, the murine model of DMD. However, ineffective delivery of AOs limits their therapeutic potential. Copolymers of cationic poly(ethylene imine (PEI and non-ionic poly(ethylene glycol (PEG form stable nanoparticles when complexed with AOs, but the positive surface charge on the resultant PEG-PEI-AO nanoparticles limits their biodistribution. We adapted a modified double emulsion procedure for encapsulating PEG-PEI-AO polyplexes into degradable polylactide-co-glycolic acid (PLGA nanospheres. Formulation parameters were varied including PLGA molecular weight, ester end-capping, and sonication energy/volume. Our results showed successful encapsulation of PEG-PEI-AO within PLGA nanospheres with average diameters ranging from 215 to 240 nm. Encapsulation efficiency ranged from 60 to 100%, and zeta potential measurements confirmed shielding of the PEG-PEI-AO cationic charge. Kinetic measurements of 17 kDa PLGA showed a rapid burst release of about 20% of the PEG-PEI-AO, followed by sustained release of up to 65% over three weeks. To evaluate functionality, PEG-PEI-AO polyplexes were loaded into PLGA nanospheres using an AO that is known to induce dystrophin expression in dystrophic mdx mice. Intramuscular injections of this compound into mdx mice resulted in over 300 dystrophin-positive muscle fibers distributed throughout the muscle cross-sections, approximately 3.4 times greater than for injections of AO alone. We conclude that PLGA nanospheres are effective compounds for the sustained release of PEG-PEI-AO polyplexes in skeletal muscle and concomitant expression of dystrophin, and may have translational potential in treating DMD.

  10. Biocompatibility Assessment of Polyethylene Glycol-Poly L-Lysine-Poly Lactic-Co-Glycolic Acid Nanoparticles In Vitro and In Vivo.

    Science.gov (United States)

    Guo, Liting; Chen, Baoan; Liu, Ran; Xia, Guohua; Wang, Yonglu; Li, Xueming; Wei, Chen; Wang, Xuemei; Jiang, Hulin

    2015-05-01

    The present study was designed to evaluate the biocompatibility of nanoparticles polyethylene glycol (PEG)-poly L-lysine (PLL)-poly lactic-co-glycolic acid copolymer (PLGA) (PEG-PLL-PLGA) before clinical application. We applied some tests to assess the safety of PEG-PLL-PLGA nanoparticles (NPs). There was low cytotoxicity of PEG-PLL-PLGA NPs in vitro as detected by MTT assay. Cell apoptosis and intracellular accumulation of PEG-PLL-PLGA were determined by FCM assay. The apoptotic rate induced by nanoparticles and the fluorescence intensity of intracellular daunorubicin (DNR) demonstrated that DNR-PEG-PLL-PLGA could be taken up by the mouse fibroblast cells (L929 cells). Hemolysis test and micronucleus (MN) assay demonstrated that the nanoparticles have no obviously blood toxicity and genotoxicity. DNR-PEG-PLL-PLGA NPs were injected into mice through tail vein to calculate the median lethal dose (LD50), the results showed that they had a wide safe scale. Blood was taken by removing the eyeball of mice to study the influence of DNR-PEG-PLL-PLGA in hepatic and renal functions. The results revealed that there was no significant difference as compared with the control group. Interestingly, the pathologic changes of heart, liver, spleen, lung and kidney were observed in nanoparticles treated mice. Thus, this study demonstrates that PEG-PLL-PLGA NPs appear to be highly biocompatible and safe nanoparticles that can be suitable for further application in the treatment of tumor.

  11. Solubility of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycols 400 or 600, propylene glycol and water at 298.2K - experimental data and modeling

    OpenAIRE

    Bastami Zahra; Soltanpour Shahla; Panahi-Azar Vahid; Jouyban Abolghasem

    2014-01-01

    Experimental molar solubilities of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycols (PEGs) 400 or 600, propylene glycol (PG) and water (138 data points) along with the density of the saturated solutions at 298.2K were reported. The Jouyban-Acree model was used to fit to the measurements for providing a computational method. Employing the solubilities in the mono-solvents, the measured solubilities in mixed solvents were back-ca...

  12. Enhanced antifouling behaviours of polyvinylidene fluoride membrane modified through blending with nano-TiO{sub 2}/polyethylene glycol mixture

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Wang, Zhiwei, E-mail: zwwang@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Zhang, Xingran [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Zheng, Xiang, E-mail: zhengxiang7825@163.com [School of Environment and Natural Resources, Renmin University of China, Beijing, 100872 (China); Wu, Zhichao [State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China)

    2015-08-01

    Graphical abstract: - Highlights: • Nano-TiO{sub 2}/polyethylene glycol (PEG) mixture was used to modify PVDF membranes. • The steric hindrance effects of PEG enabled the dispersion of nanoparticles. • The energy barrier between SMP and modified membranes was increased. • The modification by nano-TiO{sub 2}/PEG well improved the anti-fouling ability. - Abstract: Titanium dioxide (TiO{sub 2}) nanoparticles/polyethylene glycol (PEG) mixture was used to modify polyvinylidene fluoride (PVDF) membranes aiming to improve their antifouling ability. The use of PEG could improve the dispersion of nanoparticles thanks to steric hindrance effects. Test results showed that compared to the original PVDF membrane, the modified membranes had higher hydrophilicity and lower negative Zeta potential, facilitating membrane fouling control. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) analysis indicated that the addition of TiO{sub 2} nanoparticles improved their electron donor monopolarity, i.e., enhanced electron-donating ability. The interaction energy barrier between soluble microbial products (SMP) and membrane surfaces was also improved, indicating that anti-fouling ability of the modified membrane was elevated. The optimal dosage of nano-TiO{sub 2} was found to be 0.15%, and further increase of dosage resulted in the aggregation of nanoparticles which consequently impaired the modification efficiency. Quartz crystal microbalance with dissipation (QCM-D) monitoring and SMP filtration tests confirmed the antifouling ability of the modified membrane.

  13. Enhanced antifouling behaviours of polyvinylidene fluoride membrane modified through blending with nano-TiO2/polyethylene glycol mixture

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Nano-TiO2/polyethylene glycol (PEG) mixture was used to modify PVDF membranes. • The steric hindrance effects of PEG enabled the dispersion of nanoparticles. • The energy barrier between SMP and modified membranes was increased. • The modification by nano-TiO2/PEG well improved the anti-fouling ability. - Abstract: Titanium dioxide (TiO2) nanoparticles/polyethylene glycol (PEG) mixture was used to modify polyvinylidene fluoride (PVDF) membranes aiming to improve their antifouling ability. The use of PEG could improve the dispersion of nanoparticles thanks to steric hindrance effects. Test results showed that compared to the original PVDF membrane, the modified membranes had higher hydrophilicity and lower negative Zeta potential, facilitating membrane fouling control. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) analysis indicated that the addition of TiO2 nanoparticles improved their electron donor monopolarity, i.e., enhanced electron-donating ability. The interaction energy barrier between soluble microbial products (SMP) and membrane surfaces was also improved, indicating that anti-fouling ability of the modified membrane was elevated. The optimal dosage of nano-TiO2 was found to be 0.15%, and further increase of dosage resulted in the aggregation of nanoparticles which consequently impaired the modification efficiency. Quartz crystal microbalance with dissipation (QCM-D) monitoring and SMP filtration tests confirmed the antifouling ability of the modified membrane

  14. Synthesis of bridged β-cyclodextrin–polyethylene glycol and evaluation of its inhibition performance in oilfield wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Changjun, E-mail: changjunzou@126.com; Liu, Yuan; Yan, Xueling; Qin, Yibie; Wang, Meng; Zhou, Lu

    2014-10-15

    The bridged β-cyclodextrin–polyethylene glycol (β-CD–PEG) is synthesized through reaction of β-CD with PEG, which has been characterized by Fourier transform infrared spectroscope. The inhibition efficiency of bridged β-CD–PEG on corrosion of Q235 carbon steel in 0.5 M HCl solution has been investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. The results show that β-CD–PEG acted as a mixed-type inhibitor and performed excellent inhibiting effect for the corrosion of the Q235 carbon steel. The steel surface morphologies are analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) and then an adsorption mechanism model is proposed. The high inhibitory efficiency of β-CD–PEG is related with the adsorption of polymer molecules at the steel surface and a protective film formation. Finally, these results present a novel corrosion inhibitor works in oil-gas field. - Highlights: • The bridged β-CD–PEG is synthesized by polyethylene glycol and cyclodextrin. • The bridged β-CD–PEG acts as an inhibitor for carbon steel in oilfield wastewater. • The high inhibitory efficiency is related with a protective film formation. • The adsorption of β-CD–PEG is well described by the Langmuir adsorption isotherm.

  15. Poly(ethylene glycol) on the liposome surface: on the mechanism of polymer-coated liposome longevity.

    Science.gov (United States)

    Torchilin, V P; Omelyanenko, V G; Papisov, M I; Bogdanov, A A; Trubetskoy, V S; Herron, J N; Gentry, C A

    1994-10-12

    The hypothetical model is built explaining the molecular mechanism of protective action of poly(ethylene glycol) on liposomes in vivo. The protective layer of the polymer on the liposome surface is considered as a statistical 'cloud' of polymer possible conformations in solution. Computer simulation was used to demonstrate that relatively a small number of liposome-grafted molecules of hydrophilic and flexible polymer can create a dense protective conformational cloud over the liposome surface preventing opsonizing protein molecules from contacting liposome. A more rigid polymer fails to form this dense protective cloud, even when hydrophilic. Computer simulation was also used to reveal possible heterogeneity of reactive sites on a polymer-coated liposome surface, and to estimate the optimal polymer-to-lipid ratio for efficient liposome protection. Experiments have been performed with the quenching of liposome-associated fluorescent label (nitrobenzoxadiazole or fluorescein) with protein (rhodamine-ovalbumin or anti-fluorescein antibody) from solution. It was shown that poly(ethylene glycol) grafting to liposomes hinders protein interaction with the liposome surface, whereas liposome-grafted dextran (more rigid polymer) in similar quantities does not affect protein-liposome interaction. Highly-reactive and low-reactive populations of chemically identical reactive sites have been found on polymer-coated liposomes. Experimental data satisfactory confirm the suggested mechanism for the longevity of polymer-modified liposome.

  16. Influence of polyethylene glycol coating on biodistribution and toxicity of nanoscale graphene oxide in mice after intravenous injection

    Directory of Open Access Journals (Sweden)

    Li B

    2014-10-01

    Full Text Available Bo Li,1,2 Xiao-Yong Zhang,1 Jian-Zhong Yang,1 Yu-Jie Zhang,1 Wen-Xin Li,1 Chun-Hai Fan,1 Qing Huang1 1Laboratory of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 2Department of Human Anatomy, College of Basic Medical Sciences, Jilin University, Changchun, People’s Republic of China Abstract: In this study, we assessed the in vivo behavior and toxicology of nanoscale graphene oxide (NGO in mice after intravenous injection. The influence of a polyethylene glycol (PEG coating on the distribution and toxicity of the NGO was also investigated. The results show that NGO is mainly retained in the liver, lung, and spleen. Retention in the lung is partially due to NGO aggregation. The PEG coating reduces the retention of NGO in the liver, lung, and spleen and promotes the clearance of NGO from these organs, but NGO and NGO-PEG are still present after 3 months. The PEG coating effectively reduces the early weight loss caused by NGO and alleviates NGO-induced acute tissue injuries, which can include damage to the liver, lung, and kidney, and chronic hepatic and lung fibrosis. Keywords: graphene oxide, biodistribution, toxicity, polyethylene glycol

  17. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Science.gov (United States)

    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....

  18. Prospective controlled study on the effects of polyethylene glycol in capsule endoscopy

    Institute of Scientific and Technical Information of China (English)

    Takafumi Ito; Ken Ohata; Akiko Ono; Hideyuki Chiba; Yosuke Tsuji; Hajime Sato; Nobuyuki Matsuhashi

    2012-01-01

    AIM:To prospectively confirm whether a small amount of polyethylene glycol (PEG) ingested after swallowing endoscopy capsule improves image quality and completion rate.METHODS:Forty-four consecutive patients referred to us for capsule endoscopy (CE) were randomized to two groups.All patients were restricted to clear fluids for 12 h before the examination.Patients in group A (22cases) received no additional preparation,while those in group B (20 cases) ingested 500 mL of PEG within a 2 h period starting 30 min after swallowing the capsule.Clear fluids and meals were allowed 2 h and 4 h after capsule ingestion,respectively.Image quality was assessed as the percentage of visualized bowel surface area as follows:1:< 25%; 2:25%-49%; 3:50%-74%;4:75%-89%; 5:> 90%.The small bowel record was divided into five segments by time,and the score for each segment was evaluated.All CE examinations were performed with the Pillcam SB capsule endoscopy system (Given Imaging Co.Ltd.,Yoqnem).RESULTS:This study ended in December 2009,because sample size was considered large enough.A total of 44 patients were enrolled.Two patients in group B were excluded from the analysis because small bowel images could not be obtained from these patients; one had a full stomach,while the other presented with a massive gastric bleed.Thus,22 patients from group A and 20 patients from group B completed the study.There was no significant difference in age (P =0.22),sex (P =0.31),and indication for CE.No significant adverse events occurred in any of the study patients.In group A,image quality deteriorated as the capsule progressed distally.However,in group B,image quality was maintained to the distal small bowel.In each of the five segments,the visibility score was significantly higher in group B than in group A (segment 1:4.3 ±0.7 vs 4.7 ± 0.5,P =0.03; segment 2:4.2 ± 0.9 vs 4.8± 0.4,P =0.01; segment 3:4.0 ± 1.0 vs 4.6 ± 0.7,P=0.04; segment 4:3.6 ± 1.1 vs 4.5 ± 0.6,P =0

  19. Vapor pressures of a homologous series of polyethylene glycols as a reference data set for validating vapor pressure measurement techniques.

    Science.gov (United States)

    Krieger, Ulrich; Marcolli, Claudia; Siegrist, Franziska

    2015-04-01

    The production of secondary organic aerosol (SOA) by gas-to-particle partitioning is generally represented by an equilibrium partitioning model. A key physical parameter which governs gas-particle partitioning is the pure component vapor pressure, which is difficult to measure for low- and semivolatile compounds. For typical atmospheric compounds like e.g. citric acid or tartaric acid, vapor pressures have been reported in the literature which differ by up to six orders of magnitude [Huisman et al., 2013]. Here, we report vapor pressures of a homologous series of polyethylene glycols (triethylene glycol to octaethylene glycol) determined by measuring the evaporation rate of single, levitated aerosol particles in an electrodynamic balance. We propose to use those as a reference data set for validating different vapor pressure measurement techniques. With each addition of a (O-CH2-CH2)-group the vapor pressure is lowered by about one order of magnitude which makes it easy to detect the lower limit of vapor pressures accessible with a particular technique down to a pressure of 10-8 Pa at room temperature. Reference: Huisman, A. J., Krieger, U. K., Zuend, A., Marcolli, C., and Peter, T., Atmos. Chem. Phys., 13, 6647-6662, 2013.

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

    OpenAIRE

    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...

  1. Tribological characteristics of polyethylene glycol (PEG) as a lubricant for wear resistance of ultra-high-molecular-weight polyethylene (UHMWPE ) in artificial knee join.

    Science.gov (United States)

    Kobayashi, Masanori; Koide, Takayuki; Hyon, Suong-Hyu

    2014-10-01

    For the longevity of total knee joint prostheses, we have developed an artificial lubricant using polyethylene glycol (PEG) for the prevention of wear of ultra-high-molecular-weight polyethylene (UHMWPE). In the present study, the lubricative function of this PEG lubricant was evaluated by a wear test using Co-Cr alloy and UHMWPE counter surface samples. As a result, human synovial fluid including the PEG lubricant showed good result regarding the wear volume and a worn surface of UHMWPE. Considering its lubrication mechanism, it is suspected that interaction between the PEG molecules and the proteins in synovial fluid was involved. Since PE molecules are also organic compounds having a hydroxyl group at one or both ends, the albumin and PEG molecule complex would have bound more strongly to the metal oxide surface and UHMWPE surfaces might enhance and stabilize the lubricating film between the contact surfaces under the boundary lubrication. This study suggests that PEG lubricant as an intra-articular viscous supplement has the potential to prevent wear of UHMWPE by mixing with synovial fluid and to contribute to the longevity of knee joint prostheses.

  2. Thermodynamic study of copper sulphate and zinc sulphate in water and binary aqueous mixtures of propylene glycol

    Directory of Open Access Journals (Sweden)

    R. C. Thakur

    2015-03-01

    Full Text Available Partial molar volumes of copper sulphate and zinc sulphate have been determined in water and binary aqueous mixtures of propylene glycol (2,4,6 and 8% by weight of propylene glycol at 303.15 K with the help of density measurements. Effect of temperature on the partial molar volumes was also analysed for these salts in water and binary aqueous mixtures of propylene glycol. Results obtained have been analysed by Masson’s equation and the experimental values of slopes and partial molar volumes of these transition metals sulphates have been interpreted in terms of ion-ion or ion –solvent interactions. Limiting molar expansibilities ( have also been determined which is interpreted in terms of structure making or breaking capacities of transition metal sulphates. The transition metal sulphates have been found as structure promoter in water and binary aqueous mixture of propylene glycol.

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

    International Nuclear Information System (INIS)

    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)

  4. Synthesis and Characterization of Silicate Ester Prodrugs and Poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) Block Copolymers for Formulation into Prodrug-Loaded Nanoparticles

    Science.gov (United States)

    Wohl, Adam Richard

    Fine control of the physical and chemical properties of customized materials is a field that is rapidly advancing. This is especially critical in pursuits to develop and optimize novel nanoparticle drug delivery. Specifically, I aim to apply chemistry concepts to test the hypothesis "Silicate ester prodrugs of paclitaxel, customized to have the proper hydrophobicity and hydrolytic lability, can be formulated with well-defined, biocompatible, amphiphilic block copolymers into nanoparticles that are effective drugs." Chapter 1 briefly describes the context and motivation of the scientific pursuits described in this thesis. In Chapter 2, a family of model silicate esters is synthesized, the hydrolysis rate of each compound is benchmarked, and trends are established based upon the steric bulk and leaving group ability of the silicate substituents. These trends are then applied to the synthesis of labile silicate ester prodrugs in Chapter 3. The bulk of this chapter focuses on the synthesis, hydrolysis, and cytotoxicity of prodrugs based on paclitaxel, a widely used chemotherapeutic agent. In Chapter 4, a new methodology for the synthesis of narrowly dispersed, "random" poly(lactic-co-glycolic acid) polymers by a constant infusion of the glycolide monomer is detailed. Using poly(ethylene glycol) as a macroinitiator, amphiphilic block copolymers were synthesized. Co-formulating a paclitaxel silicate and an amphiphilic block copolymer via flash nanoprecipitation led to highly prodrug-loaded, kinetically trapped nanoparticles. Studies to determine the structure, morphology, behavior, and efficacy of these nanoparticles are described in Chapter 5. Efforts to develop a general strategy for the selective end-functionalization of the polyether block of these amphiphilic block copolymers are discussed in Chapter 6. Examples of this strategy include functionalization of the polyether with an azide or a maleimide. Finally, Chapter 7 provides an outlook for future development of

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  7. The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavadi, Ali, E-mail: purjavad@sharif.edu; Tehrani, Zahra Mazaheri; Mahmoudi, Negar [Sharif University of Technology, Polymer Research Laboratory, Department of Chemistry (Iran, Islamic Republic of)

    2015-04-15

    In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating of PEG reduced the wrapping of the protein corona around the nanoparticles. This phenomenon caused increase in Dox release.

  8. The influence of pH, polyethylene glycol and polyacrylic acid on the stability of stem bromelain

    Directory of Open Access Journals (Sweden)

    Letícia Celia de Lencastre Novaes

    2014-04-01

    Full Text Available Enzyme stability is critical in biotechnology, pharmaceutical and cosmetic industries. Investigations on this subject have drawn attention because of its practical application. Bromelain is a thiol-endopeptidase, obtained from pineapple (Ananas comosus, known for its clinical and therapeutic applications, particularly to selective burn debridement and improvement of antibiotic action and anti-inflammatory activities. To date, the use of bromelain in pharmacological or industrial applications is limited, due to commercial availability, costs, and sensitivity to pH and temperature. Therefore, a better understanding of enzyme stability would be of great interest. The aim of this study was to evaluate bromelain activity and stability in several pH (2.0 to 8.0 and in polyethylene glycol and polyacrylic acid solutions. We observed that bromelain was able to maintain its stability at pH 5.0 for the temperatures studied. PEG solutions increased bromelain stability, but PAA solutions had the opposite effect.

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

    Science.gov (United States)

    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

  10. SURFACE MODIFICATION OF BLEND FILMS COMPOSED OF SILK FIBROIN AND POLY(ETHYLENE GLYCOL) MACROMER AND THEIR IN VITRO ANTITHROMBOGENICITY

    Institute of Scientific and Technical Information of China (English)

    Hua-xin Sun; Song Wang; He-sun Zhu

    2004-01-01

    In order to improve the blood compatibility of silk fibroin (SF), poly(ethylene glycol) macromer (PEGM) in different amounts was added to the SF film to incorporate C=C group into the surface of blend films which were then modified by SO2 gas plasma treatment. ATR-FITR and XPS were used to analyze the chemical change which had occurred on the film's surface. When the content of sulfur on the surface of blend films surpasses 1.59%, the antithrombogenicity of plasma treated films increases remarkably due to surface sulfonation. This result implies that SF with blend of PEGM after SO2 plasma treatment have potential use for making blood-contacting biomaterials.

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

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2013-01-01

    Full Text Available This paper proposed a novel method to prepare porous calcium silicate hydrate (CSH based on the calcium oxide/polyethylene glycol (CaO/PEG2000 composites as the calcium materials. The porosity formation mechanism was revealed via X-ray diffraction (XRD, field-emission scanning electron microscopy (FESEM, Brunauer-Emmett-Teller (BET, and Fourier transformed infrared spectroscopy (FT-IR. The reactivity of silica materials (SiO2 enhanced by increasing pH value. Ca2+ could not sustain release from CaO/PEG2000 and reacted with caused by silica to form CSH until the hydrothermal temperature reached to 170°C, avoiding the hardly dissolved intermediates formation efficiently. The as-prepared CSH, due to the large specific surface areas, exhibited excellent release capability of Ca2+ and OH−. This porous CSH has potential application in reducing the negative environmental effects of continual natural phosphate resource depletion.

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

    Science.gov (United States)

    Kweon, Haeyong; Yeo, Joo-hong; Lee, Kwang-gill; Lee, Hyun Chul; Na, Hee Sam; Won, Young Ho; Cho, Chong Su

    2008-09-01

    Semi-interpenetrating polymer networks (SIPNs) composed of silk fibroin (SF) and poly(ethylene glycol) (PEG) were prepared by photopolymerization of a PEG macromer in the presence of SF to improve the mechanical properties of SF sponge as wound dressing. The morphological structure of the SF/PEG SIPNs was observed to be composed of an interconnected microporous surface and a cross-sectional area. SF/PEG SIPNs showed non-cytotoxicity evaluated by a cell proliferation method using L929 fibroblasts. Wound contraction treated with SF/PEG SIPNs sponges was faster than that of Vaseline gauze as a control. Histological observation confirmed that the deposition of collagen in the dermis was organized by covering the wound area with SF/PEG SIPNs. The above results indicated that SF/PEG SIPNs could be used as wound dressing.

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

    International Nuclear Information System (INIS)

    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. Shifting product formation from xylitol to ethanol in pentose fermentations using Candida tropicalis by adding polyethylene glycol (PEG)

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B.; Joensson, B.; Lohmeier-Vogel, E.

    1985-02-01

    When Candida tropicalis fermented xylose under oxygen limited conditions in the presence of increasing concentrations of polyethylene glycol (PEG), the ethanol production increased by a factor of two and the xylitol production was repressed by about 25%. Xylose assimilation and cell growth were not affected by the presence of PEG. The fermentation of glucose was not as strongly influenced by the presence of PEG as were xylose fermentations. The results are discussed in relation to the physico-chemical properties of a medium containing increasing concentrations of PEG. It is suggested that the presence of PEG might result in a fine-tuning of the aeration in the medium, necessary for ethanol production from xylose with Candida tropicalis.

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

    International Nuclear Information System (INIS)

    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

  16. Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles

    Science.gov (United States)

    Shen, Zhiqiang; Loe, David T.; Awino, Joseph K.; Kröger, Martin; Rouge, Jessica L.; Li, Ying

    2016-08-01

    Herein a new multifunctional formulation, referred to as a core-polyethylene glycol-lipid shell (CPLS) nanoparticle, has been proposed and studied in silico via large scale coarse-grained molecular dynamics simulations. A PEGylated core with surface tethered polyethylene glycol (PEG) chains is used as the starting configuration, where the free ends of the PEG chains are covalently bonded with lipid molecules (lipid heads). A complete lipid bilayer is formed at the surface of the PEGylated particle core upon addition of free lipids, driven by the hydrophobic properties of the lipid tails, leading to the formation of a CPLS nanoparticle. The self-assembly process is found to be sensitive to the grafting density and molecular weight of the tethered PEG chains, as well as the amount of free lipids added. At low grafting densities the assembly of CPLS nanoparticles cannot be accomplished. As demonstrated by simulations, a lipid bud/vesicle can be formed on the surface when an excess amount of free lipids is added at high grafting density. Therefore, the CPLS nanoparticles can only be formed under appropriate conditions of both PEG and free lipids. The CPLS nanoparticle has been recognized to be able to store a large quantity of water molecules, particularly with high molecular weight of PEG chains, indicating its capacity for carrying hydrophilic molecules such as therapeutic biomolecules or imaging agents. Under identical size and surface chemistry conditions of a liposome, it has been observed that the CPLS particle can be more efficiently wrapped by the lipid membrane, indicating its potential for a greater efficiency in delivering its hydrophilic cargo. As a proof-of-concept, the experimental realization of CPLS nanoparticles is explicitly demonstrated in this study. To test the capacity of the CPLS to store small molecule cargo a hydrophilic dye was successfully encapsulated in the particles' water soluble layer. The results of this study show the power and

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

    Science.gov (United States)

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

    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 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.

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

    Science.gov (United States)

    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.

  19. Long-Term Controlled Protein Release from Poly(Ethylene Glycol) Hydrogels by Modulating Mesh Size and Degradation.

    Science.gov (United States)

    Tong, Xinming; Lee, Soah; Bararpour, Layla; Yang, Fan

    2015-12-01

    Poly(ethylene glycol) (PEG)-based hydrogels are popular biomaterials for protein delivery to guide desirable cellular fates and tissue repair. However, long-term protein release from PEG-based hydrogels remains challenging. Here, we report a PEG-based hydrogel platform for long term protein release, which allows efficient loading of proteins via physical entrapment. Tuning hydrogel degradation led to increase in hydrogel mesh size and gradual release of protein over 60 days of with retained bioactivity. Importantly, this platform does not require the chemical modification of loaded proteins, and may serve as a versatile tool for long-term delivery of a wide range of proteins for drug-delivery and tissue-engineering applications.

  20. Radiosensitivity enhancement of typical 15 nm polyethylene-glycol-coated Au nanoparticles on HepG2 cell

    International Nuclear Information System (INIS)

    Objective: To investigate the radiosensitivity enhancement of Au nanoparticles to HepG2 cell. Methods: 15 nm polyethylene-glycol-coated(PEG) Au nanoparticles were synthesized, and then blood stability were tested by using the UV-vis optical absorption. Meanwhile, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide methods were used to investigate the cell viability after 24 and 48 hours treatments, and cloning formation were used to investigate the radiosensitivity enhancement. Results: It was found that PEG-coated Au nanoparticles presented a high blood stability, and surface plasmon response has not shown significant changes after 24 hours. Cell viability was decreased after 24 hours treatment, but it was recovered to 90% after 48 hours. Cloning formation showed Au nanoparticles presented a significant radiosensitivity enhancement. Conclusion: 15 nm PEG-coated Au nanoparticles presented a good blood stability, low cytotoxicity and high radiosensitivity enhancement. (authors)

  1. Study of the reaction between polyethylene glycol and epoxy resins using N,N-dimethylbenzylamine as catalyst

    International Nuclear Information System (INIS)

    In this work the use of N,N-dimethylbenzylamine as a catalyst of the reaction of polyethylene glycol (PEG) and epoxy resin (DGEBA) was studied. The reaction products were evaluated by infra-red spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR) and viscosity measurements. Samples cured with a polyamine-based hardener were also submitted to tensile tests and differential scanning calorimetry (DSC). The results of the viscosity analyses, FTIR and RMN (1H) had confirmed the occurrence of the reaction between DGEBA epoxy groups and PEG hydroxyl groups in the presence of N, N-dimethylbenzylamine as catalyst, at 100 deg C. DSC analyses and tensile tests of cured systems showed that the reaction of DGEBA with PEG leads to a reduction of the Tg, generating a more flexible material. (author)

  2. Photodynamic therapy of tumors with pyropheophorbide-a-loaded polyethylene glycol–poly(lactic-co-glycolic acid) nanoparticles

    Science.gov (United States)

    Liu, Hui; Zhao, Mei; Wang, Jin; Pang, Mingpei; Wu, Zhenzhou; Zhao, Liqing; Yin, Zhinan; Hong, Zhangyong

    2016-01-01

    Photodynamic therapy (PDT) has many advantages in treating cancers, but the lack of ideal photosensitizers continues to be a major limitation restricting the clinical utility of PDT. This study aimed to overcome this obstacle by generating pyropheophorbide-a-loaded polyethylene glycol–poly(lactic-co-glycolic acid) nanoparticles (NPs) for efficient tumor-targeted PDT. The fabricated NPs were efficiently internalized in the mitochondrion by cancer cells, and they efficiently killed cancer cells in a dose-dependent manner when activated with light. Systemically delivered NPs were highly enriched in tumor sites, and completely ablated the tumors in a xenograft KB tumor mouse model when illuminated with 680 nm light (156 mW/cm2, 10 minutes). The results suggested that this tumor-specific NP-delivery system for pyropheophorbide-a has the potential to be used in tumor-targeted PDT. PMID:27729788

  3. Effects of one-seed juniper and polyethylene glycol on intake, rumen fermentation, and plasma amino acids in sheep and goats fed supplemental protein and tannins.

    Science.gov (United States)

    We tested the effect of polyethylene glycol (PEG) on juniper and total intake, rumen fermentation, and plasma amino acids (AA) of 12 does and 12 ewes fed sudangrass and basal diets containing 10% quebracho tannins with no protein supplement (Control; 5% CP) or high rumen degradable (RDP 15% CP) or u...

  4. In vitro and in vivo comparisons of staphylococcal biofilm formation on a cross-linked poly(ethylene glycol)-based polymer coating.

    NARCIS (Netherlands)

    Saldarriaga Fernandez, I.C.; Mei, H.C. van der; Metzger, S.; Grainger, D.W.; Engelsman, A.F.; Nejadnik, M.R.; Busscher, H.J.

    2010-01-01

    Poly(ethylene glycol) (PEG) coatings are known to reduce microbial adhesion in terms of numbers and binding strength. However, bacterial adhesion remains of the order of 10(4)cm(-2). It is unknown whether this density of bacteria will eventually grow into a biofilm. This study investigates the kinet

  5. A facile one-pot ultrasound assisted for an efficient synthesis of benzo[g]chromenes using Fe3O4/polyethylene glycol (PEG) core/shell nanoparticles.

    Science.gov (United States)

    Safaei-Ghomi, Javad; Eshteghal, Fahime; Shahbazi-Alavi, Hossein

    2016-11-01

    In this research, a general synthetic method for the synthesis of benzo[g]chromenes has been developed using Fe3O4/polyethylene glycol (PEG) core/shell nanoparticle under ultrasonic irradiations. Compared to the conventional methods, ultrasound procedure showed several advantages including mild reaction conditions, high yield products, short reaction times, reusability of the catalyst and little catalyst loading. PMID:27245961

  6. Poly(ethylene glycol) hydroxystearate-based nanosized emulsions: effect of surfactant concentration on their formation and ability to solubilize quercetin.

    Science.gov (United States)

    Dora, Cristiana L; Silva, Luis F C; Putaux, Jean-Luc; Nishiyama, Yoshiharu; Pignot-Paintrand, Isabelle; Borsali, Redouane; Lemos-Senna, Elenara

    2012-04-01

    Quercetin is a natural compound that has shown several biological activities. However, it displays poor water solubility and, therefore, low bioavailability. In this study, oil-in-water nanosized emulsions were obtained by the hot solvent diffusion method, using castor oil as oily phase and poly(ethylene glycol) (660)-12-hydroxystearate (PEG 660-stearate) and lecithin as surfactants. The effect of the PEG 660-stearate concentration on the droplet size of the nanosized emulsions and on the ability of these systems to load quercetin was investigated. Dynamic light scattering (DLS), transmission electron microscopy (TEM), cryo-TEM, and small-angle X-ray scattering (SAXS) were used to characterize the systems. We have demonstrated that a critical concentration of PEG 660-stearate (2.5 wt%) was needed to obtain colloidal dispersions displaying microemulsion characteristics. This colloidal dispersion, that was not optically birefringent, was constituted by a monodisperse population of 20 nm-large droplets, and exhibited excellent stability. Besides, this system was able to solubilize five times more quercetin than nanoemulsions prepared using 0.25 wt% PEG 660-stearate. SAXS results suggest that the spherical droplets have a core-shell structure. With regard to the hot solvent diffusion method, both diffusion of the solvent towards the aqueous phase and increase of the temperature above the phase inversion temperature (PIT) of PEG 660-stearate appeared to be required for obtaining clear and isotropic colloidal dispersions. PMID:22515071

  7. Injectable polyethylene glycol-fibrinogen hydrogel adjuvant improves survival and differentiation of transplanted mesoangioblasts in acute and chronic skeletal-muscle degeneration

    Directory of Open Access Journals (Sweden)

    Fuoco Claudia

    2012-11-01

    Full Text Available Abstract Background Cell-transplantation therapies have attracted attention as treatments for skeletal-muscle disorders; however, such research has been severely limited by poor cell survival. Tissue engineering offers a potential solution to this problem by providing biomaterial adjuvants that improve survival and engraftment of donor cells. Methods In this study, we investigated the use of intra-muscular transplantation of mesoangioblasts (vessel-associated progenitor cells, delivered with an injectable hydrogel biomaterial directly into the tibialis anterior (TA muscle of acutely injured or dystrophic mice. The hydrogel cell carrier, made from a polyethylene glycol-fibrinogen (PF matrix, is polymerized in situ together with mesoangioblasts to form a resorbable cellularized implant. Results Mice treated with PF and mesoangioblasts showed enhanced cell engraftment as a result of increased survival and differentiation compared with the same cell population injected in aqueous saline solution. Conclusion Both PF and mesoangioblasts are currently undergoing separate clinical trials: their combined use may increase chances of efficacy for localized disorders of skeletal muscle.

  8. Mechanical and swelling characterization of poly(N-isopropyl acrylamide -co- methoxy poly(ethylene glycol) methacrylate) sol-gels.

    Science.gov (United States)

    Pollock, Jacob F; Healy, Kevin E

    2010-04-01

    The dimensional stability and rheological properties of a series of comb-like copolymers of N-isopropyl acrylamide (NIPAAm) and methoxy poly(ethylene glycol) methacrylate (mPEGMA), poly(NIPAAm-co-mPEGMA), with varying poly(ethylene glycol) (PEG) graft densities and molecular weights were studied. The thermoresponsive character of the copolymer solutions was investigated by kinetic and equilibrium swelling, as well as by static and dynamic mechanical analysis. Surface response mapping was employed to target particular compositions and concentrations with excellent dimensional stability and a relatively large change in dynamic mechanical properties upon thermoreversible gelation. The mechanical characteristics of the gels depended strongly upon concentration of total polymer and less so upon copolymer ratio. Increased PEG graft density was shown to slow the deswelling rate and increase the equilibrium water content of the gels. Upon gelation at sol concentrations of 1-20 wt.% the materials underwent no deswelling or syneresis and maintained stable gels with a large elastic regime and high yield strain (i.e. elastic and soft but tough), even within the Pascal range of complex shear moduli. These materials are unique in that they maintained a physiologically useful lower critical solution temperature (approximately 33 degrees C), despite having a high PEG content. Copolymers with a high PEG content and low polymer fraction were conveniently transparent in the gel phase, allowing visualization of cellular activity without disrupting the microenvironment. Mesenchymal stem cells showed good viability and proliferation in three-dimensional culture within the gels, despite the lack of ligand incorporation to promote cellular interaction. Multi-component matrices can be created through simple mixing of copolymer solutions and peptide-conjugated linear polymers and proteins to produce combinatorial microenvironments with the potential for use in cell biology, tissue

  9. Calibration and validation of the 14C-labelled polyethylene glycol-binding assay for tannins in tropical browse

    International Nuclear Information System (INIS)

    This study evaluates the radiolabelled polyethylene glycol (PEG)-binding procedure [Silanikove, N., Shinder, D., Gilboa, N., Eyal, M., Nitsan, Z., 1996. Polyethylene glycol-binding to plant samples as an assay for the biological effects of tannins: predicting the negative effects of tannins in Mediterranean browse on rumen degradation. J. Agric. Food Chem. 44, 3230-3234] for tannin analysis, using 27 tropical browse plants. In this method, the amount of PEG bound to a plant sample is assumed to be a reflection of its tannin content. The method was modified to exclude the use of non-tanniniferous substrate for estimating non-specific binding (NSB) in tannin-containing substrates. Non-specific binding values varied widely (0.4-2.8 mg PEG/100 mg DM tannin-free substrate) when the tannin-free substrate was changed from wheat straw to either rye grass or maize shoots. We therefore propose a modified radiolabelled PEG-binding method to estimate the level of PEG-binding (PEGb) to tannin-containing foliage without using tannin-free substrate to correct for non-specific binding. In this approach, incremental levels of each tanniniferous substrate were used to generate PEGb values. The resultant linear response was analysed and tannin activity was expressed as the slope of the response curve (PEGbSlope) observed for each substrate. The slope takes into account the non-specific binding in each substrate, thus PEGbSlope does not require correction for NSB using tannin-free samples. This approach improved the correlation between PEGb and the 125I-labelled bovine serum albumin precipitation assay. Relationships between the modified PEG-binding assay and radiolabelled bovine serum albumin assay, in vitro tannin bioassay and colorimetric assays are presented. (author)

  10. The influence of tannin, pectin and polyethylene glycol on attachment of 15N-labelled rumen microorganisms to cellulose

    International Nuclear Information System (INIS)

    The microbial attachment to and gas production from α-cellulose (Sigma; C-8002) without and with mimosa tannin (MT), pectin (P), polyethylene glycol (PEG), MT + P or MT + PEG, were investigated using the in vitro gas production system. Microbial attachment based on 15N-labelled rumen microorganisms in the residual pellet after 24 h incubation was estimated, which varied from 113.7 to 161.3 μg 15N per g residual pellet. C + MT had the lowest microbial attachment (P 2 = 0.84, P 15N) in the residual pellet measured for C + MT (0.054) and C + MT + P (0.159), compared with the other treatments (0.32 for C; 0.34 for C + P; 0.33 for C + PEG; and 0.33 for C + MT + PEG). A MT concentration of 194 g/kg diet reduced microbial attachment and activity of rumen microorganisms in vitro. Polyethylene glycol counteracted the effect of MT on microbial attachment and activity. Pectin exerted a beneficial effect on attachment and fermentation in the initial hours of incubation. A ratio of pectin to MT of 1:1 improved microbial activity of C + MT but inhibition of microbial activity by MT remained at 24 h as indicated by the lower gas production of C + MT + P compared with the control. The results support the hypothesis that there is considerable interaction between tannins, microbes and non-starch-polysaccharides (NSP) in animal feeds and that these interactions may influence the functional ability of microbes in the gastrointestinal tract of animals. (author)

  11. Self-assembled poly(ethylene glycol)-co-acrylic acid microgels to inhibit bacterial colonization of synthetic surfaces.

    Science.gov (United States)

    Wang, Qichen; Uzunoglu, Emel; Wu, Yong; Libera, Matthew

    2012-05-01

    We explored the use of self-assembled microgels to inhibit the bacterial colonization of synthetic surfaces both by modulating surface cell adhesiveness at length scales comparable to bacterial dimensions (∼1 μm) and by locally storing/releasing an antimicrobial. Poly(ethylene glycol) [PEG] and poly(ethylene glycol)-co-acrylic acid [PEG-AA] microgels were synthesized by suspension photopolymerization. Consistent with macroscopic gels, a pH dependence of both zeta potential and hydrodynamic diameter was observed in AA-containing microgels but not in pure PEG microgels. The microgels were electrostatically deposited onto poly(l-lysine) (PLL) primed silicon to form submonolayer surface coatings. The microgel surface density could be controlled via the deposition time and the microgel concentration in the parent suspension. In addition to their intrinsic antifouling properties, after deposition, the microgels could be loaded with a cationic antimicrobial peptide (L5) because of favorable electrostatic interactions. Loading was significantly higher in PEG-AA microgels than in pure PEG microgels. The modification of PLL-primed Si by unloaded PEG-AA microgels reduced the short-term (6 h) S. epidermidis surface colonization by a factor of 2, and the degree of inhibition increased when the average spacing between microgels was reduced. Postdeposition L5 peptide loading into microgels further reduced bacterial colonization to the extent that, after 10 h of S. epidermidis culture in tryptic soy broth, the colonization of L5-loaded PEG-AA microgel-modified Si was comparable to the very small level of colonization observed on macroscopic PEG gel controls. The fact that these microgels can be deposited by a nonline-of-sight self-assembly process and hinder bacterial colonization opens the possibility of modifying the surfaces of topographically complex biomedical devices and reduces the rate of biomaterial-associated infection. PMID:22519439

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

    International Nuclear Information System (INIS)

    Wound dressings of chitosan are biocompatible, biodegradable, antibacterial and hemostatic biomaterials. However, applications for chitosan are limited due to its poor mechanical properties. Here, we conducted an in vivo mouse angiogenesis study on reinforced poly(ethylene glycol) (PEG)-chitosan (RPC) hydrogels. RPC hydrogels were formed by cross-linking chitosan with PEGs of different molecular weights at various PEG to chitosan ratios in our previous paper. These dressings can keep the wound moist, had good gas exchange capacity, and was capable of absorbing or removing the wound exudate. We examined the ability of these RPC hydrogels and neat chitosan to heal small cuts and full-thickness skin defects on the backs of male Balb/c mice. Histological examination revealed that chitosan suppressed the infiltration of inflammatory cells and accelerated fibroblast proliferation, while PEG enhanced epithelial migration. The RPC hydrogels promoted wound healing in the small cuts and full layer wounds. The optimal RPC hydrogel had a swelling ratio of 100% and a water vapor transmission rate (WVTR) of about 2000 g/m2/day. In addition, they possess good mechanical property and appropriate degradation rates. Thus, the optimal RPC hydrogel formulation functioned effectively as a wound dressing and promoted wound healing. Highlights: ► Mouse angiogenesis study on reinforced poly(ethylene glycol)-chitosan (RPC) ► Water vapor transmission rate of about 2000 g/m2/day is characteristic of RPC. ► RPC suppressed inflammatory cells and accelerated fibroblast proliferation. ► RPC composed of 1000-RP10C90 can be used as a biomaterial for wound dressing

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  14. Biomass Yield and Steviol Glycoside Production in Callus and Suspension Culture of Stevia rebaudiana Treated with Proline and Polyethylene Glycol.

    Science.gov (United States)

    Gupta, Pratibha; Sharma, Satyawati; Saxena, Sanjay

    2015-06-01

    Enhanced production of steviol glycosides (SGs) was observed in callus and suspension culture of Stevia rebaudiana treated with proline and polyethylene glycol (PEG). To study their effect, yellow-green and compact calli obtained from in vitro raised Stevia leaves were sub-cultured on MS medium supplemented with 2.0 mg l(-1) NAA and different concentrations of proline (2.5-10 mM) and PEG (2.5-10 %) for 2 weeks, and incubated at 24 ± 1 °C and 22.4 μmol m(-2) s(-1) light intensity provided by white fluorescent tubes for 16 h. Callus and suspension culture biomass (i.e. both fresh and dry weight content) was increased with 5 mM proline and 5 % PEG, while at further higher concentrations, they got reduced. Further, quantification of SGs content in callus (collected at 15th day) and suspension culture (collected at 10th and 15th day) treated with and without elicitors was analysed by HPLC. It was observed that chemical stress enhanced the production of SGs significantly. In callus, the content of SGs increased from 0.27 (control) to 1.09 and 1.83 % with 7.5 mM proline and 5 % PEG, respectively, which was about 4.0 and 7.0 times higher than control. However, in the case of suspension culture, the same concentrations of proline and polyethylene glycol enhanced the SG content from 1.36 (control) to 5.03 and 6.38 %, respectively, on 10th day which were 3.7 times and 4.7 times higher than control.

  15. In vitro and in vivo effects of polyethylene glycol (PEG-modified lipid in DOTAP/cholesterol-mediated gene transfection

    Directory of Open Access Journals (Sweden)

    Torben Gjetting

    2010-05-01

    Full Text Available Torben Gjetting1, Nicolai Skovbjerg Arildsen1, Camilla Laulund Christensen1, Thomas Tuxen Poulsen1, Jack A Roth3, Vagn Neerup Handlos2, Hans Skovgaard Poulsen11Department of Radiation Biology, Finsen Center, 2RH Pharmacy, Copenhagen University Hospital, Copenhagen, Denmark; 3Thoracic Medical Oncology, MD Anderson Cancer Centre, Houston, TX, USABackground: DOTAP/cholesterol-based lipoplexes are successfully used for delivery of plasmid DNA in vivo especially to the lungs, although low systemic stability and circulation have been reported. To achieve the aim of discovering the best method for systemic delivery of DNA to disseminated tumors we evaluated the potential of formulating DOTAP/cholesterol lipoplexes with a polyethylene glycol (PEG-modified lipid, giving the benefit of the shielding and stabilizing properties of PEG in the bloodstream.Method: A direct comparison of properties in vitro and in vivo of 4 different DOTAP/cholesterol-based lipoplexes containing 0%, 2%, 4%, and 10% PEG was performed using reporter gene activity and radioactive tracer lipid markers to monitor biodistribution.Results: We found that 10% PEGylation of lipoplexes caused reduced retention in lung and heart tissues of nude mice compared to nonPEGylated lipoplexes, however no significant delivery to xenograft flank tumors was observed. Although PEGylated and nonPEGylated lipoplexes were delivered to cells the ability to mediate successful transfection is hampered upon PEGylation, presumably due to a changed uptake mechanism and intracellular processing.Conclusion: The eminent in vivo transfection potency of DOTAP/cholesterol-based lipoplexes is well established for expression in lung tumors, but it is unsuitable for expression in non first pass organs such as xenograft flank tumors in mice even after addition of a PEG-lipid in the formulation.Keywords: gene delivery, DOTAP, polyethylene glycol (PEG, biodistribution, lung cancer, xenograft tumor model

  16. Biomass Yield and Steviol Glycoside Production in Callus and Suspension Culture of Stevia rebaudiana Treated with Proline and Polyethylene Glycol.

    Science.gov (United States)

    Gupta, Pratibha; Sharma, Satyawati; Saxena, Sanjay

    2015-06-01

    Enhanced production of steviol glycosides (SGs) was observed in callus and suspension culture of Stevia rebaudiana treated with proline and polyethylene glycol (PEG). To study their effect, yellow-green and compact calli obtained from in vitro raised Stevia leaves were sub-cultured on MS medium supplemented with 2.0 mg l(-1) NAA and different concentrations of proline (2.5-10 mM) and PEG (2.5-10 %) for 2 weeks, and incubated at 24 ± 1 °C and 22.4 μmol m(-2) s(-1) light intensity provided by white fluorescent tubes for 16 h. Callus and suspension culture biomass (i.e. both fresh and dry weight content) was increased with 5 mM proline and 5 % PEG, while at further higher concentrations, they got reduced. Further, quantification of SGs content in callus (collected at 15th day) and suspension culture (collected at 10th and 15th day) treated with and without elicitors was analysed by HPLC. It was observed that chemical stress enhanced the production of SGs significantly. In callus, the content of SGs increased from 0.27 (control) to 1.09 and 1.83 % with 7.5 mM proline and 5 % PEG, respectively, which was about 4.0 and 7.0 times higher than control. However, in the case of suspension culture, the same concentrations of proline and polyethylene glycol enhanced the SG content from 1.36 (control) to 5.03 and 6.38 %, respectively, on 10th day which were 3.7 times and 4.7 times higher than control. PMID:25940589

  17. Calibration and validation of the {sup 14}C-labelled polyethylene glycol-binding assay for tannins in tropical browse

    Energy Technology Data Exchange (ETDEWEB)

    Mlambo, V. [Animal Production Unit, FAO/IAEA Agriculture and Biotechnology Laboratory, Seibersdorf (Austria)]. E-mail: vmlambo@agric.uniswa.sz; Makkar, H.P.S. [Animal Production and Health Section, Joint FAO/IAEA Division of Nuclear Techniques in Agriculture and Food, International Atomic Energy Agency, Vienna (Austria)

    2005-08-19

    This study evaluates the radiolabelled polyethylene glycol (PEG)-binding procedure [Silanikove, N., Shinder, D., Gilboa, N., Eyal, M., Nitsan, Z., 1996. Polyethylene glycol-binding to plant samples as an assay for the biological effects of tannins: predicting the negative effects of tannins in Mediterranean browse on rumen degradation. J. Agric. Food Chem. 44, 3230-3234] for tannin analysis, using 27 tropical browse plants. In this method, the amount of PEG bound to a plant sample is assumed to be a reflection of its tannin content. The method was modified to exclude the use of non-tanniniferous substrate for estimating non-specific binding (NSB) in tannin-containing substrates. Non-specific binding values varied widely (0.4-2.8 mg PEG/100 mg DM tannin-free substrate) when the tannin-free substrate was changed from wheat straw to either rye grass or maize shoots. We therefore propose a modified radiolabelled PEG-binding method to estimate the level of PEG-binding (PEGb) to tannin-containing foliage without using tannin-free substrate to correct for non-specific binding. In this approach, incremental levels of each tanniniferous substrate were used to generate PEGb values. The resultant linear response was analysed and tannin activity was expressed as the slope of the response curve (PEGbSlope) observed for each substrate. The slope takes into account the non-specific binding in each substrate, thus PEGbSlope does not require correction for NSB using tannin-free samples. This approach improved the correlation between PEGb and the {sup 125}I-labelled bovine serum albumin precipitation assay. Relationships between the modified PEG-binding assay and radiolabelled bovine serum albumin assay, in vitro tannin bioassay and colorimetric assays are presented. (author)

  18. Polyethylene glycol-coupled IGF1 delays motor function defects in a mouse model of spinal muscular atrophy with respiratory distress type 1.

    Science.gov (United States)

    Krieger, Frank; Elflein, Nicole; Saenger, Stefanie; Wirthgen, Elisa; Rak, Kristen; Frantz, Stefan; Hoeflich, Andreas; Toyka, Klaus V; Metzger, Friedrich; Jablonka, Sibylle

    2014-05-01

    Spinal muscular atrophy with respiratory distress type 1 is a neuromuscular disorder characterized by progressive weakness and atrophy of the diaphragm and skeletal muscles, leading to death in childhood. No effective treatment is available. The neuromuscular degeneration (Nmd(2J)) mouse shares a crucial mutation in the immunoglobulin mu-binding protein 2 gene (Ighmbp2) with spinal muscular atrophy with respiratory distress type 1 patients and also displays some basic features of the human disease. This model serves as a promising tool in understanding the complex mechanisms of the disease and in exploring novel treatment modalities such as insulin-like growth factor 1 (IGF1) which supports myogenic and neurogenic survival and stimulates differentiation during development. Here we investigated the treatment effects with polyethylene glycol-coupled IGF1 and its mechanisms of action in neurons and muscles. Polyethylene glycol-coupled IGF1 was applied subcutaneously every second day from post-natal Day 14 to post-natal Day 42 and the outcome was assessed by morphology, electromyography, and molecular studies. We found reduced IGF1 serum levels in Nmd(2J) mice 2 weeks after birth, which was normalized by polyethylene glycol-coupled IGF1 treatment. Nmd(2J) mice showed marked neurogenic muscle fibre atrophy in the gastrocnemius muscle and polyethylene glycol-coupled IGF1 treatment resulted in muscle fibre hypertrophy and slowed fibre degeneration along with significantly higher numbers of functionally active axonal sprouts. In the diaphragm with predominant myogenic changes a profound protection from muscle fibre degeneration was observed under treatment. No effects of polyethylene glycol-coupled IGF1 were monitored at the level of motor neuron survival. The beneficial effects of polyethylene glycol-coupled IGF1 corresponded to a marked activation of the IGF1 receptor, resulting in enhanced phosphorylation of Akt (protein kinase B) and the ribosomal protein S6 kinase in

  19. The influence of freeze drying and ϒ-irradiation in pre-clinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using D-(+-trehalose and polyethylene glycol

    Directory of Open Access Journals (Sweden)

    Ramos Yacasi GR

    2016-08-01

    Full Text Available Gladys Rosario Ramos Yacasi, María Luisa García López, Marta Espina García, Alexander Parra Coca, Ana Cristina Calpena Campmany Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, University of Barcelona, Barcelona, Spain Abstract: This study investigated the suspension of poly(ε-caprolactone nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5% and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350 and d-(+-trehalose (TRE. Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen’s egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE. IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over .30 days. This study concludes that both formulations meet the Goldman’s criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics

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

    Energy Technology Data Exchange (ETDEWEB)

    Humbe, Ashok V.; Birajdar, Shankar D.; Jadhav, K. M., E-mail: drjadhavkm@gmail.com [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, (M. S.) (India); Bhandari, J. M. [Department of Physics, Gandhi College, Kada, Ashti, Beed, (M. S.) (India); Waghule, N. N. [Department of Physics, Bhagwan Mahavidyalay, Ashti, Beed, (M. S.) (India); Bhagwat, V. R. [Institute of Shipbuilding Technology, Bogda-Vasco, Goa (India)

    2015-06-24

    The structural and magnetic properties of the polyethylene glycol (PEG) coated cobalt spinel ferrite (CoFe{sub 2}O{sub 4}) nanoparticles have been reported in the present study. CoFe{sub 2}O{sub 4} nanoparticles were prepared by sol-gel auto-combustion method using citric acid + ethylene glycol as a fuel. The prepared powder of cobalt ferrite nanoparticles was annealed at 600°C for 6h and used for further study. The structural characterization of CoFe{sub 2}O{sub 4} nanoparticles were carried out by X-ray diffraction technique. The X-ray analysis confirmed the formation of single phase cubic spinel structure. The crystallite size, Lattice constant and X-ray density of the PEG coated CoFe{sub 2}O{sub 4} nanoparticles were calculated by using XRD data. The presence of PEG on CoFe{sub 2}O{sub 4} nanoparticles and reduced agglomeration in the CoFe{sub 2}O{sub 4} nanoparticles were revealed by SEM studies. The magnetic properties were studied by pulse field hysteresis loop tracer technique at a room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, coercivity etc have been obtained. These magnetic parameters were get decreased by PEG coating.

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

    Science.gov (United States)

    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

  2. Enhancing the in vivo transdermal delivery of gold nanoparticles using poly(ethylene glycol and its oleylamine conjugate

    Directory of Open Access Journals (Sweden)

    Hsiao PF

    2016-05-01

    Full Text Available Pa Fan Hsiao,1–3 Sydney Peng,4 Ting-Cheng Tang,4 Shuian-Yin Lin,5 Hsieh-Chih Tsai4 1Department of Dermatology, Mackay Memorial Hospital, 2Mackay Medicine, Nursing and Management College, 3Mackay Medical College, New Taipei City, 4Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 5National Applied Research Laboratories, Instrument Technology Research Center, Hsinchu, Taiwan Abstract: In this study, we investigated the effect of (ethylene glycol (PEG and PEG–oleylamine (OAm functionalization on the skin permeation property of gold nanoparticles (GNS in vivo. Chemisorption of polymers onto GNS was verified by a red shift in the ultraviolet–visible spectrum as well as by a change in the nanoparticle surface charge. The physicochemical properties of pristine and functionalized nanoparticles were analyzed by ultraviolet–visible spectroscopy, zeta potential analyzer, and transmission electron microscopy. Transmission electron microscopy revealed that the interparticle distance between nanoparticles increased after GNS functionalization. Comparing the skin permeation profile of pristine and functionalized GNS, the follicular deposition of GNS increased twofold after PEG–OAm functionalization. Moreover, PEG- and PEG–OAm-functionalized nanoparticles were able to overcome the skin barrier and deposit in the deeper subcutaneous adipose tissue. These findings demonstrate the potential of PEG- and PEG–OAm-functionalized GNS in serving a multitude of applications in transdermal pharmaceuticals. Keywords: skin penetration, amphiphilic copolymer, gold nanoparticle, oleylamine, poly(ethylene glycol

  3. Modification of hydrophobic acrylic intraocular lens with poly(ethylene glycol) by atmospheric pressure glow discharge: A facile approach

    International Nuclear Information System (INIS)

    To improve the anterior surface biocompatibility of hydrophobic acrylic intraocular lens (IOL) in a convenient and continuous way, poly(ethylene glycol)s (PEGs) were immobilized by atmospheric pressure glow discharge (APGD) treatment using argon as the discharge gas. The hydrophilicity and chemical changes on the IOL surface were characterized by static water contact angle and X-ray photoelectron spectroscopy to confirm the covalent binding of PEG. The morphology of the IOL surface was observed under field emission scanning electron microscopy and atomic force microscopy. The surface biocompatibility was evaluated by adhesion experiments with platelets, macrophages, and lens epithelial cells (LECs) in vitro. The results revealed that the anterior surface of the PEG-grafted IOL displayed significantly and permanently improved hydrophilicity. Cell repellency was observed, especially in the PEG-modified IOL group, which resisted the attachment of platelets, macrophages and LECs. Moreover, the spread and growth of cells were suppressed, which may be attributed to the steric stabilization force and chain mobility effect of the modified PEG. All of these results indicated that hydrophobic acrylic IOLs can be hydrophilic modified by PEG through APGD treatment in a convenient and continuous manner which will provide advantages for further industrial applications.

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

    International Nuclear Information System (INIS)

    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. Modification of hydrophobic acrylic intraocular lens with poly(ethylene glycol) by atmospheric pressure glow discharge: A facile approach

    Energy Technology Data Exchange (ETDEWEB)

    Lin Lin; Wang Yao; Huang Xiaodan [Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China); Xu Zhikang [Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Yao Ke, E-mail: xlren@zju.edu.cn [Eye Center, Affiliated Second Hospital, College of Medicine, Zhejiang University, Hangzhou 310009 (China)

    2010-10-01

    To improve the anterior surface biocompatibility of hydrophobic acrylic intraocular lens (IOL) in a convenient and continuous way, poly(ethylene glycol)s (PEGs) were immobilized by atmospheric pressure glow discharge (APGD) treatment using argon as the discharge gas. The hydrophilicity and chemical changes on the IOL surface were characterized by static water contact angle and X-ray photoelectron spectroscopy to confirm the covalent binding of PEG. The morphology of the IOL surface was observed under field emission scanning electron microscopy and atomic force microscopy. The surface biocompatibility was evaluated by adhesion experiments with platelets, macrophages, and lens epithelial cells (LECs) in vitro. The results revealed that the anterior surface of the PEG-grafted IOL displayed significantly and permanently improved hydrophilicity. Cell repellency was observed, especially in the PEG-modified IOL group, which resisted the attachment of platelets, macrophages and LECs. Moreover, the spread and growth of cells were suppressed, which may be attributed to the steric stabilization force and chain mobility effect of the modified PEG. All of these results indicated that hydrophobic acrylic IOLs can be hydrophilic modified by PEG through APGD treatment in a convenient and continuous manner which will provide advantages for further industrial applications.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. IMMOBILIZATION OF POTENTIALLY BIOACTIVE MOIETIES ONTO POLYETHER WITH POLY(ETHYLENE GLYCOL)-SULFONATE SPACER

    Institute of Scientific and Technical Information of China (English)

    JI Jian; FENG Linxian; QIU Yongxin; YU Xiaojie; YANG Shilin

    1997-01-01

    A new reactive graft copolymer, poly(tetramethylene glycol)-graft-ω-propyl sodium sulfonate-poly(ethylene glycol) (PTMG-g-PEG-CH2CH2CH2SO-3Na+), was synthesized by the cationic polymerization of α-ω-bifunctional PEG macromonomer ((o)CH2-PEG--CH2CH2CH2SO3Na ) and THF. The obtained copolymer exhibits the expected structure as indicated by the result of characterization. Two amino acids (L-arginine, L-tyrosine) were covalently attached to the copolymer after converting the sulfonate group to sulfonyl chloride. So the new reactive graft copolymer (PTMG-g-PEG-CH2CH2CH2SO-3Na+) is expected to be very useful in attachment of potentially bioactive moieties to polymer via a hydrophilic PEG spacer.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  11. Fragment-based solid-phase assembly of oligonucleotide conjugates with peptide and polyethylene glycol ligands.

    Science.gov (United States)

    Dirin, Mehrdad; Urban, Ernst; Noe, Christian R; Winkler, Johannes

    2016-10-01

    Ligand conjugation to oligonucleotides is an attractive strategy for enhancing the therapeutic potential of antisense and siRNA agents by inferring properties such as improved cellular uptake or better pharmacokinetic properties. Disulfide linkages enable dissociation of ligands and oligonucleotides in reducing environments found in endosomal compartments after cellular uptake. Solution-phase fragment coupling procedures for producing oligonucleotide conjugates are often tedious, produce moderate yields and reaction byproducts are frequently difficult to remove. We have developed an improved method for solid-phase coupling of ligands to oligonucleotides via disulfides directly after solid-phase synthesis. A 2'-thiol introduced using a modified nucleotide building block was orthogonally deprotected on the controlled pore glass solid support with N-butylphosphine. Oligolysine peptides and a short monodisperse ethylene glycol chain were successfully coupled to the deprotected thiol. Cleavage from the resin and full removal of oligonucleotide protection groups were achieved using methanolic ammonia. After standard desalting, and without further purification, homogenous conjugates were obtained as demonstrated by HPLC, gel electrophoresis, and mass spectrometry. The attachment of both amphiphilic and cationic ligands proves the versatility of the conjugation procedure. An antisense oligonucleotide conjugate with hexalysine showed pronounced gene silencing in a cell culture tumor model in the absence of a transfection reagent and the corresponding ethylene glycol conjugate resulted in down regulation of the target gene to nearly 50% after naked application. PMID:27236069

  12. D-α-tocopherol polyethylene glycol succinate-based derivative nanoparticles as a novel carrier for paclitaxel delivery

    Directory of Open Access Journals (Sweden)

    Wu YP

    2015-08-01

    Full Text Available Yupei Wu,1,* Qian Chu,2,* Songwei Tan,1 Xiangting Zhuang,1 Yuling Bao,1 Tingting Wu,1 Zhiping Zhang1,3,41Tongji School of Pharmacy, 2Department of Oncology, Tongji Hospital, Tongji Medical School, 3Hubei Engineering Research Center for NDDS, 4National Engineering Research Center for Nanomedicine, Huazhong University of Science and Technology, Wuhan, People’s Republic of China*These authors contributed equally to this workAbstract: Paclitaxel (PTX is one of the most effective antineoplastic drugs. Its current clinical administration Taxol® is formulated in Cremophor EL, which causes serious side effects. Nanoparticles (NP with lower systemic toxicity and enhanced therapeutic efficiency may be an alternative formulation of the Cremophor EL-based vehicle for PTX delivery. In this study, novel amphipathic 4-arm-PEG-TPGS derivatives, the conjugation of D-α-tocopherol polyethylene glycol succinate (TPGS and 4-arm-polyethylene glycol (4-arm-PEG with different molecular weights, have been successfully synthesized and used as carriers for the delivery of PTX. These 4-arm-PEG-TPGS derivatives were able to self-assemble to form uniform NP with PTX encapsulation. Among them, 4-arm-PEG5K-TPGS NP exhibited the smallest particle size, highest drug-loading efficiency, negligible hemolysis rate, and high physiologic stability. Therefore, it was chosen for further in vitro and in vivo investigations. Facilitated by the effective uptake of the NP, the PTX-loaded 4-arm-PEG5K-TPGS NP showed greater cytotoxicity compared with free PTX against human ovarian cancer (A2780, non-small cell lung cancer (A549, and breast adenocarcinoma cancer (MCF-7 cells, as well as a higher apoptotic rate and a more significant cell cycle arrest effect at the G2/M phase in A2780 cells. More importantly, PTX-loaded 4-arm-PEG5K-TPGS NP resulted in a significantly improved tumor growth inhibitory effect in comparison to Taxol® in S180 sarcoma-bearing mice models. This study suggested

  13. Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles.

    Science.gov (United States)

    Shen, Zhiqiang; Loe, David T; Awino, Joseph K; Kröger, Martin; Rouge, Jessica L; Li, Ying

    2016-08-21

    Herein a new multifunctional formulation, referred to as a core-polyethylene glycol-lipid shell (CPLS) nanoparticle, has been proposed and studied in silico via large scale coarse-grained molecular dynamics simulations. A PEGylated core with surface tethered polyethylene glycol (PEG) chains is used as the starting configuration, where the free ends of the PEG chains are covalently bonded with lipid molecules (lipid heads). A complete lipid bilayer is formed at the surface of the PEGylated particle core upon addition of free lipids, driven by the hydrophobic properties of the lipid tails, leading to the formation of a CPLS nanoparticle. The self-assembly process is found to be sensitive to the grafting density and molecular weight of the tethered PEG chains, as well as the amount of free lipids added. At low grafting densities the assembly of CPLS nanoparticles cannot be accomplished. As demonstrated by simulations, a lipid bud/vesicle can be formed on the surface when an excess amount of free lipids is added at high grafting density. Therefore, the CPLS nanoparticles can only be formed under appropriate conditions of both PEG and free lipids. The CPLS nanoparticle has been recognized to be able to store a large quantity of water molecules, particularly with high molecular weight of PEG chains, indicating its capacity for carrying hydrophilic molecules such as therapeutic biomolecules or imaging agents. Under identical size and surface chemistry conditions of a liposome, it has been observed that the CPLS particle can be more efficiently wrapped by the lipid membrane, indicating its potential for a greater efficiency in delivering its hydrophilic cargo. As a proof-of-concept, the experimental realization of CPLS nanoparticles is explicitly demonstrated in this study. To test the capacity of the CPLS to store small molecule cargo a hydrophilic dye was successfully encapsulated in the particles' water soluble layer. The results of this study show the power and

  14. Effects of hydration on the thermodynamic properties of aqueous ethylene glycol ether solutions

    Energy Technology Data Exchange (ETDEWEB)

    Schroedle, Simon [Institut fuer Physikalische und Theoretische Chemie, Universitaet Regensburg, D-93040 Regensburg (Germany); Hefter, Glenn [Chemistry Department, DSE Murdoch University, Murdoch, WA 6150 (Australia); Buchner, Richard [Institut fuer Physikalische und Theoretische Chemie, Universitaet Regensburg, D-93040 Regensburg (Germany)]. E-mail: richard.buchner@chemie.uni-regensburg.de

    2005-05-15

    The densities and isobaric specific heat capacities of binary mixtures of water with various open-chain and cyclic ethylene glycol ethers have been measured at 298.15 K using vibrating tube densimetry, and flow or differential scanning calorimetry, respectively. Excess molar volumes were derived over the whole composition range. Molar isobaric heat capacities and the relative apparent thermodynamic quantities were determined in the water-rich region. The data reflect the changes in the structure and hydrogen-bond dynamics of water caused by these non-ionic solutes. The observed effects are discussed in terms of the influence of hydrophobic hydration on the thermodynamic properties of aqueous solutions. Correlations are given that enable the prediction of the thermodynamic properties of open-chain and cyclic oligo(ethylene oxide) ethers in their pure liquid state and at infinite dilution in water.

  15. Yields of hydrogen peroxide in radiolysis of aqueous ethylene glycol solutions

    International Nuclear Information System (INIS)

    The main source of information on mechanisms for the formation of H2O2 and other molecular water radiolysis products is the dependence of their yields on the concentration of a substance (S) dissolved in the water. A diffusion/recombination model for water radiolysis predicts that at low (≤0.1 mole/dm3) concentrations of S in water (C/sub S/) the yields of molecular water radiolysis products (G/sub M/), i.e., H2 and H2O2, drop linearly with the cube root of C/sub S/. This paper attempts to prove the assumption experimentally by studying how G/sub H2O2/, the ideal water breakdown yield, is affected by high concentrations of ethylene glycol in deaerated aqueous solutions. The observed radiolytic yield of H2O2 in this system agreed with the initial G/sub H2O2/

  16. GRAFTING OF ETHYLENE GLYCOL DIMETHACRYLATE ONTO SILK IN AQUEOUS ALCOHOLIC SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Hong-wei Liu; Chuan-fu Chen; Fu Xi

    2003-01-01

    The grafting of ethylene glycol dimethacrylate (EGDMA) onto silk in aqueous alcohol systems using potassium persulfate (KPS) in the presence of air was investigated. Effects of grafting conditions, such as concentrations of monomer,initiator and formic acid, temperature and time, on the graft yield were determined. The optimum graft conditions were found to be: T= 80℃, t = 30 min, [KPS] = 1.85% [on the weight of monomer (owm)]; [formic acid] = 0.2% (V/V); [EGDMA] =80% [on the weight of fiber (owf)]. The activation energy of grafting at 50-80℃ was found to be 71.31 kJ/mol for EGDMA.Grafting equations were also evaluated. The graft yield value can be regulated by the concentration of monomer. The graft copolymerization of EGDMA onto silk is effective in improving the crease-proofing of silk fabrics.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  18. Use of polyethylene glycol for the improvement of the cycling stability of bischofite as thermal energy storage material

    International Nuclear Information System (INIS)

    Highlights: • Bischofite as phase change material for TES is studied. • Thermophysical properties of bischofite mixtures with PEG were determined. • The aim was to improve the cycling stability of bischofite. • The heating and cooling during 30 cycles were measured. • The most stable sample was bischofite + 5% PEG 2 000. - Abstract: Bischofite is a by-product of the non-metallic mining industry. It has been evaluated as phase change material in thermal energy storage, but it shows little cycling stability, therefore in this paper the mixture of bischofite with an additive was studied. Since polyethylene glycol (PEG) is a PCM itself, in this paper PEG (with different molecular weights) is used as additive in a PCM (bischofite) to improve its thermal behaviour. Results show that adding 5% PEG 2 000 to bischofite gives a more cycling stable PCM without affecting its melting temperature neither decreasing significantly its heat of fusion. This research shows that mixing an inorganic PCM with an organic additive can be a good option to improve the thermal performance of the PCM

  19. Efficacy and biodistribution of tocopheryl polyethylene glycol succinate noncovalent functionalized single walled nanotubes loading doxorubicin in sarcoma bearing mouse model.

    Science.gov (United States)

    Wang, Yongjun; Xu, Hui; Liu, Hongzhuo; Wang, Yan; Sun, Jin; He, Zhonggui

    2012-06-01

    The aim of this study is to develop the noncovalent functionalized single walled nanotubes loading doxorubicin. A tocopheryl polyethylene glycol succinate (TPGS) noncovalent modification of single walled carbon nanotubes (SWNTs) loading antitumor agent doxorubicin (Dox) via the physical absorption was developed. Dox was successfully loaded onto the surface of carbon nanotubes (loading amount was 168.7 microg/ml), which was confirmed by UV-vis-NIR absorbance spectra and dynamic light scattering assay. ICR mice bearing mouse sarcoma tumor were subjected to intratumoral injection of TPGS-SWNTs-Dox. Based on the in vivo antitumor activities of the locally injected the formulation into the tumor bearing mice, it was shown that there was modest (up to 50.2%) delay of tumor growth compared with the groups receiving no treatment, which was better than free dox (up to 40.2%). The biodistribution studies demonstrated that there were the longest retention time in tumor, the highest tumor accumulation, as well as less accumulation in other solid tissues, especially in heart, when tumor bearing mice were administered with TPGS-SWNTs-Dox. It may be attributed to the enhanced permeability and retention (EPR) effect of TPGS-SWNTs-Dox. The histopathological findings revealed that the new carbon nanomaterials were a safe vehicle for topical drug delivery systems. These results suggested that the noncovalent modification of carbon nanotubes by TPGS for anticancer agents may be a promising strategy for cancer treatment. PMID:22764414

  20. Fabrication of poly(ethylene glycol): gelatin methacrylate composite nanostructures with tunable stiffness and degradation for vascular tissue engineering

    International Nuclear Information System (INIS)

    Although synthetic polymers are desirable in tissue engineering applications for the reproducibility and tunability of their properties, synthetic small diameter vascular grafts lack the capability to endothelialize in vivo. Thus, synthetically fabricated biodegradable tissue scaffolds that reproduce important aspects of the extracellular environment are required to meet the urgent need for improved vascular grafting materials. In this study, we have successfully fabricated well-defined nanopatterned cell culture substrates made of a biodegradable composite hydrogel consisting of poly(ethylene glycol) dimethacrylate (PEGDMA) and gelatin methacrylate (GelMA) by using UV-assisted capillary force lithography. The elasticity and degradation rate of the composite PEG–GelMA nanostructures were tuned by varying the ratios of PEGDMA and GelMA. Human umbilical vein endothelial cells (HUVECs) cultured on nanopatterned PEG–GelMA substrates exhibited enhanced cell attachment compared with those cultured on unpatterned PEG–GelMA substrates. Additionally, HUVECs cultured on nanopatterned PEG-GelM substrates displayed well-aligned, elongated morphology similar to that of native vascular endothelial cells and demonstrated rapid and directionally persistent migration. The ability to alter both substrate stiffness and degradation rate and culture endothelial cells with increased elongation and alignment is a promising next step in recapitulating the properties of native human vascular tissue for tissue engineering applications. (paper)

  1. Poly(acrylic acid)/polyethylene glycol hygrogel prepared by using gamma-ray irradiation for mucosa adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young-Chang; Park, Jong-Seok; Shin, Jung-Woong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Gwon, Hui-Jeong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Khil, Myung-Seob [Chonbuk National University, Jeonju (Korea, Republic of); Lee, Deok-Won [Maxillofacial Surgery Dental Hospital, Seoul (Korea, Republic of); Ahn, Sung-Jun [JADAM Co., LTD., Seogwipo (Korea, Republic of)

    2015-01-15

    A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

  2. Impact of polyethylene glycol on proline and membrane stability index for water stress regime in tomato (Solanum lycopersicum)

    International Nuclear Information System (INIS)

    Drought is one of the most important constraints worldwide for crop growth including tomato. It adversely affects germination and seedling that ultimately reduces crop development and economic yield. Polyethylene glycol (PEG) gives an indication to abiotic stresses and has been used throughout world in various crops for successful screening and breeding against stresses. Contrarily proline protects plant tissues against stress through preventing molecular denaturation, scavenges reactive oxygen species and interacts with phospholipids. Present paper presents the results on PEG and proline estimation in tomato. The PEG screening reduced the experimental material and finally 20 genotypes (6232, 6233, 6234, 10584, 10587, 17889, 17902, 17904, 19288, 19289, 19290, 19291, 19893, Avinash-2, Feston, Nagina, Punjab Chohara, Ratan and T-4) from diverse origin were investigated for proline estimation, chlorophyll contents and membrane stability index that gave a clear reference for drought tolerance in tomato. All the techniques (PEG, Proline, MSI) related to drought screening were employed and their interactive interpretation will enable us to design future breeding strategies for tomato development under drought that is still a dream for man. Among 20 genotypes, 19291 possessed the highest proline contents hence was tolerant to drought conditions, although needs verification under actual drought for adaptability and yield potential. High MSI under stress was observed for Punjab Chuhara, Chuhara, Avinash-2, Ratan, 19893, 19291 and 6233. (author)

  3. Improved cellular infiltration into nanofibrous electrospun cross-linked gelatin scaffolds templated with micrometer-sized polyethylene glycol fibers

    Energy Technology Data Exchange (ETDEWEB)

    Skotak, Maciej [Biomechanics, Biomaterials and Biomedicine Instrumentation Facility, College of Engineering, University of Nebraska-Lincoln, NE 68588-0642 (United States); Ragusa, Jorge; Gonzalez, Daniela; Subramanian, Anuradha, E-mail: asubramanian2@unl.edu [Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, NE 68588-0643 (United States)

    2011-10-15

    Gelatin-based nanofibrous scaffolds with a mean fiber diameter of 300 nm were prepared with and without micrometer-sized polyethylene glycol (PEG) fibers that served as sacrificial templates. Upon fabrication of the scaffolds via electrospinning, the gelatin fibers were crosslinked with glutaraldehyde, and the PEG templates were removed using tert-butanol to yield nanofibrous scaffolds with pore diameters ranging from 10 to 100 {mu}m, as estimated with mercury intrusion porosimetry. Non-templated gelatin-based nanofibrous matrices had an average pore size of 1 {mu}m. Fibroblasts were seeded onto both types of the gelatin-based nanofibrous surfaces and cultured for 14 days. For comparative purposes, chitosan-based and polyurethane-based macroporous scaffolds with pore sizes of 100 and 170 {mu}m, respectively, were also included. The number of cells as a function of the depth into the scaffold was judged and quantitatively assessed using nuclei staining. Cell penetration up to a depth of 250 and 90 {mu}m was noted in gelatin scaffolds prepared with sacrificial templates and gelatin-only nanofibrous scaffolds. Noticeably, scaffold preparation protocol presented here allowed the structural integrity to be maintained even with high template content (95%) and can easily be extended toward other classes of electrospun polymer matrices for tissue engineering.

  4. pH-Responsive Poly(ethylene glycol)/Poly(L-lactide) Supramolecular Micelles Based on Host-Guest Interaction.

    Science.gov (United States)

    Zhang, Zhe; Lv, Qiang; Gao, Xiaoye; Chen, Li; Cao, Yue; Yu, Shuangjiang; He, Chaoliang; Chen, Xuesi

    2015-04-29

    pH-responsive supramolecular amphiphilic micelles based on benzimidazole-terminated poly(ethylene glycol) (PEG-BM) and β-cyclodextrin-modified poly(L-lactide) (CD-PLLA) were developed by exploiting the host-guest interaction between benzimidazole (BM) and β-cyclodextrin (β-CD). The dissociation of the supramolecular micelles was triggered in acidic environments. An antineoplastic drug, doxorubicin (DOX), was loaded into the supramolecular micelles as a model drug. The release of DOX from the supramolecular micelles was clearly accelerated as the pH was reduced from 7.4 to 5.5. The DOX-loaded PEG-BM/CD-PLLA supramolecular micelles displayed an enhanced intracellular drug-release rate in HepG2 cells compared to the pH-insensitive DOX-loaded PEG-b-PLLA counterpart. After intravenous injection into nude mice bearing HepG2 xenografts by the tail vein, the DOX-loaded supramolecular micelles exhibited significantly higher tumor inhibition efficacy and reduced systemic toxicity compared to free DOX. Furthermore, the DOX-loaded supramolecular micelles showed a blood clearance rate markedly lower than that of free DOX and comparable to that of the DOX-loaded PEG-b-PLLA micelles after intravenous injection into rats. Therefore, the pH-responsive PEG-BM/CD-PLLA supramolecular micelles hold potential as a smart nanocarrier for anticancer drug delivery. PMID:25856564

  5. Creating poly(ethylene glycol) film on the surface of NiTi alloy by gamma irradiation

    Science.gov (United States)

    Yu, Hongyan; Yan, Jin; Ma, Huiling; Zeng, Xinmiao; Liu, Yang; Zhao, Xinqing

    2015-07-01

    NiTi alloy has been extensively utilized as biomaterials owing to its unique shape memory effect, superelasticity and biocompatibility. However, concern with the toxic and allergic responses of nickel potentially releasing from implants stimulated lots of researches of modification on NiTi alloy surface. Creating chemical bond attachment of bioorganic film on NiTi alloy surface could effectively inhibit Ni releasing and obtain bioactive functions for further application. In this work, to get a bioorganic surface, NiTi alloy was modified with poly(ethylene glycol) (PEG) film by gamma ray induced grafting or crosslinking. X-ray diffraction (XRD) spectrum, water contact angle geometer and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize the NiTi surface. The results indicated that PEG was covalent bonded on NiTi alloy surface. Fluorescence microscope (FM) images for morphology of 1 day osteoblast culture on the PEG coated NiTi surface showed that PEG could improve cell proliferation on NiTi surface. Our work offers a way to introduce a bioorganic metal surface by gamma irradiation.

  6. Synthesis and characterization of gold nanotube/nanowire–polyurethane composite based on castor oil and polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Ganji, Yasaman, E-mail: y.ganji@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran (Iran, Islamic Republic of); Kasra, Mehran, E-mail: mkasra@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran (Iran, Islamic Republic of); Salahshour Kordestani, Soheila, E-mail: s.kordestani@aut.ac.ir [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran (Iran, Islamic Republic of); Bagheri Hariri, Mohiedin, E-mail: mohibagheri@gmail.com [Materials Science and Engineering Department, Sharif University of Technology, Azadi Ave., Tehran (Iran, Islamic Republic of)

    2014-09-01

    Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil–polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane–GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell attachment of polyurethane. Higher crosslink density and better cell attachment and proliferation were observed in polyurethane containing 50 ppm GNT/NW. The results revealed that GNT/NW formed hydrogen bonding with the polyurethane matrix and improved the thermomechanical properties of nanocomposites. Compared with pure PU, better cellular attachment on polyurethane–GNT/NW composites was observed resulting from the improved surface properties of composites. - Highlights: • Polyurethane–gold nanotubes/nanowires (GNT/NWs) composites were synthesized. • Tan δ, E′ and E″ were increased upon addition of 50 ppm of GNT/NW. • Better cell attachment was observed in composites containing 50 ppm of GNT/NW. • GNT/NWs can make a bridge between the pores of the porous polymeric scaffolds. • GNT/NWs increased the crosslink density of the polymeric matrix.

  7. Length-scale mediated adhesion and directed growth of neural cells by surface-patterned poly(ethylene glycol) hydrogels.

    Science.gov (United States)

    Krsko, Peter; McCann, Thomas E; Thach, Thu-Trang; Laabs, Tracy L; Geller, Herbert M; Libera, Matthew R

    2009-02-01

    We engineered surfaces that permit the adhesion and directed growth of neuronal cell processes but that prevent the adhesion of astrocytes. This effect was achieved based on the spatial distribution of sub-micron-sized cell-repulsive poly(ethylene glycol) [PEG] hydrogels patterned on an otherwise cell-adhesive substrate. Patterns were identified that promoted cellular responses ranging from complete non-attachment, selective attachment, and directed growth at both cellular and subcellular length scales. At the highest patterning density where the individual hydrogels almost overlapped, there was no cellular adhesion. As the spacing between individual hydrogels was increased, patterns were identified where neurites could grow on the adhesive surface between hydrogels while astrocytes were unable to adhere. Patterns such as lines or arrays were identified that could direct the growth of these subcellular neuronal processes. At higher hydrogel spacings, both neurons and astrocytes adhered and grew in a manner approaching that of unpatterned control surfaces. Patterned lines could once again direct growth at cellular length scales. Significantly, we have demonstrated that the patterning of sub-micron/nano scale cell-repulsive features at microscale lengths on an otherwise cell-adhesive surface can differently control the adhesion and growth of cells and cell processes based on the difference in their characteristic sizes. This concept could potentially be applied to an implantable nerve-guidance device that would selectively enable regrowing axons to bridge a spinal-cord injury without interference from the glial scar.

  8. Physiological, Ultrastructural and Proteomic Responses in the Leaf of Maize Seedlings to Polyethylene Glycol-Stimulated Severe Water Deficiency

    Directory of Open Access Journals (Sweden)

    Ruixin Shao

    2015-09-01

    Full Text Available After maize seedlings grown in full-strength Hoagland solution for 20 days were exposed to 20% polyethylene glycol (PEG-stimulated water deficiency for two days, plant height, shoot fresh and dry weights, and pigment contents significantly decreased, whereas malondialdehyde (MDA content greatly increased. Using transmission electron microscopy, we observed that chloroplasts of mesophyll cells in PEG-treated maize seedlings were swollen, with a disintegrating envelope and disrupted grana thylakoid lamellae. Using two-dimensional gel electrophoresis (2-DE method, we were able to identify 22 protein spots with significantly altered abundance in the leaves of treated seedlings in response to water deficiency, 16 of which were successfully identified. These protein species were functionally classified into signal transduction, stress defense, carbohydrate metabolism, protein metabolism, and unknown categories. The change in the abundance of the identified protein species may be closely related to the phenotypic and physiological changes due to PEG-stimulated water deficiency. Most of the identified protein species were putatively located in chloroplasts, indicating that chloroplasts may be prone to damage by PEG stimulated-water deficiency in maize seedlings. Our results help clarify the molecular mechanisms of the responses of higher plants to severe water deficiency.

  9. A polyethylene glycol-assisted carbothermal reduction method to synthesize LiFePO4 using industrial raw materials

    Science.gov (United States)

    Fey, George Ting-Kuo; Huang, Kai-Pin; Kao, Hsien-Ming; Li, Wen-Hsien

    2011-03-01

    Olivine LiFePO4 is synthesized by a carbothermal reduction method (CTR) using industrial raw materials with polyethylene glycol (PEG) as a reductive agent and carbon source. A required amount of acetone is added to the starting materials for the ball milling process and the precursor is sintered at 973 K for 8 h to form crystalline phase LiFePO4. The structure and morphology of the LiFePO4/C composite samples have been characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, differential scanning calorimetry and magnetic susceptibility. Electrochemical measurements show that the LiFePO4/C composite cathode delivers an initial discharge capacity of 150 mAh g-1 at a 0.2C-rate between 4.0 and 2.8 V, and almost no capacity loss is observed for up to 50 cycles. Remarkably, the cell can sustain a 30C-rate between 4.6 and 2.0 V, and this rate capability is equivalent to charge or discharge in 2 min. The simple technique, low-cost starting materials, and excellent electrochemical performance make this process easier to commercialize than other synthesized methods.

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

    Institute of Scientific and Technical Information of China (English)

    姜维; 王运东; 甘泉; 张建铮; 赵秀文; 费维扬; 贝建中; 王身国

    2006-01-01

    Diblock copolymer poly(ethylene glycol) methyl ether-polylactide (MePEG-PLA) micelles were prepared by dialysis against water. Indomethacin (IMC) as a model drug was entrapped into the micelles by dialysis method. The critical micelle concentration (CMC) of the prepared micelles in distilled water investigated by fluorescence spectroscopy was 0.0051mg/mL which is lower than that of common low molecular weight surfactants. The diameters of MePEG-PLA micelles and IMC loaded MePEG-PLA micelles in a number-averaged scale measured by dynamic light scattering were 52.4 and 53.7 nm respectively. The observation with transmission electron microscope and scanning electron microscope showed that the appearance of MePEG-PLA micelles was in a spherical shape. The content of IMC incorporated in the core portion of the micelles was 18% (ω). The effects of the synthesis method of the copolymer on the polydispersity of the micelles and the yield of the micelles formation were discussed.

  11. Modification of structural and optical properties of polyvinyl alcohol/polyethylene glycol thin film by laser irradiation

    Science.gov (United States)

    Nouh, S. A.; Benthami, K.; Abutalib, M. M.

    2016-02-01

    The effect of infrared laser irradiation on the structural and the optical properties of polyvinyl alcohol/polyethylene glycol (PVA/PEG) co-polymer has been investigated. Thin films of PVA/PEG (nearly 50 µm thickness) were irradiated up to 15 J/cm2 of Ga-As laser pulses of 904 nm, 5 W power, and 200-ns pulse duration. The resultant effect of laser irradiation on the structural properties of PVA/PEG has been investigated using X-ray diffraction and Fourier transform infrared spectroscopy (FTIR). Further, the refractive index and the color difference between the exposed samples and the pristine have been studied. FTIR spectroscopy showed that the PVA/PEG samples exhibited degradation under the effect of laser irradiation up to 9 J/cm2, where crosslinking started and continued until 15 J/cm2. The refractive index had a minimum value of 1.5020 at 9 J/cm2, accompanied by a high degree of ordering and maximum value of 1.5640 at 15 J/cm2, with an increase in disordering character due to the degradation and crosslinking formation inside the sample, respectively. Moreover, the color intensity ΔE was greatly increased with increasing the laser fluence, accompanied by a significant increase in the yellow color component.

  12. Physicochemical characterisation, drug polymer dissolution and in vitro evaluation of phenacetin and phenylbutazone solid dispersions with polyethylene glycol 8000.

    Science.gov (United States)

    Khan, Sheraz; Batchelor, Hannah; Hanson, Peter; Perrie, Yvonne; Mohammed, Afzal R

    2011-10-01

    Poor water solubility leads to low dissolution rate and consequently, it can limit bioavailability. Solid dispersions, where the drug is dispersed into an inert, hydrophilic polymer matrix can enhance drug dissolution. Solid dispersions were prepared using phenacetin and phenylbutazone as model drugs with polyethylene glycol (PEG) 8000 (carrier), by melt fusion method. Phenacetin and phenylbutazone displayed an increase in the dissolution rate when formulated as solid dispersions as compared with their physical mixture and drug alone counterparts. Characterisation of the solid dispersions was performed using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). DSC studies revealed that drugs were present in the amorphous form within the solid dispersions. FTIR spectra for the solid dispersions of drugs suggested that there was a lack of interaction between PEG 8000 and the drug. However, the physical mixture of phenacetin with PEG 8000 indicated the formation of hydrogen bond between phenacetin and the carrier. Permeability of phenacetin and phenylbutazone was higher for solid dispersions as compared with that of drug alone across Caco-2 cell monolayers. Permeability studies have shown that both phenacetin and phenylbutazone, and their solid dispersions can be categorised as well-absorbed compounds.

  13. Free radical polymerization of poly(ethylene glycol) diacrylate macromers: impact of macromer hydrophobicity and initiator chemistry on polymerization efficiency.

    Science.gov (United States)

    Dai, Xiaoshu; Chen, Xi; Yang, Laura; Foster, Sarah; Coury, Arthur J; Jozefiak, Thomas H

    2011-05-01

    A series of poly(ethylene glycol)-co-poly(lactide) diacrylate macromers was synthesized with variable PEG molecular weights (10 or 20 kDa) and lactate contents (0 or 6 lactates per end group). These macromers were polymerized to form hydrogels by free radical polymerization using either redox or photochemical initiators. The extent of polymerization was determined by monitoring the compressive modulus of the resulting hydrogels and by quantitative determination of unreacted acrylate after exhaustive hydrolysis of the gel. Polymerization efficiency was found to depend on the lactate content of the macromer, with higher lactate macromers giving more efficient polymerization. For redox-initiated polymerization using ferrous gluconate/t-butyl hydroperoxide initiator, macromers containing approximately six lactate repeats per end group required lower concentrations of initiator to reach high conversion than lactate-free macromers. Photochemical polymerization with α,α-dimethoxy-α-phenylacetophenone (Irgacure 651(®)) was found to be less efficient than redox polymerization, requiring the addition of N-vinyl-2- pyrrolidone (NVP) as a co-monomer to achieve conversions comparable with redox polymerization. When conditions were optimized to provide near complete conversion for all gels, the presence of lactate repeat units in the hydrogel was generally found to reduce swelling and increase the compressive modulus. Calculated values of molecular weight between cross-links (M(c)) and mesh size using Flory-Rehner theory showed that macromer molecular weight had the greatest impact on the network structure of the gel. PMID:21232638

  14. Gene transfection mediated by polyethyleneimine-polyethylene glycol nanocarrier prevents cisplatin-induced spiral ganglion cell damage

    Directory of Open Access Journals (Sweden)

    Guan-gui Chen

    2015-01-01

    Full Text Available Polyethyleneimine-polyethylene glycol (PEI-PEG, a novel nanocarrier, has been used for transfection and gene therapy in a variety of cells. In our previous study, we successfully carried out PEI-PEG-mediated gene transfer in spiral ganglion cells. It remains unclear whether PEI-PEG could be used for gene therapy with X-linked inhibitor of apoptosis protein (XIAP in the inner ear. In the present study, we performed PEI-PEG-mediated XIAP gene transfection in the cochlea of Sprague-Dawley rats, via scala tympani fenestration, before daily cisplatin injections. Auditory brainstem reflex tests demonstrated the protective effects of XIAP gene therapy on auditory function. Immunohistochemical staining revealed XIAP protein expression in the cytoplasm of cells in the spiral ganglion, the organ of Corti and the stria vascularis. Reverse transcription-PCR detected high levels of XIAP mRNA expression in the cochlea. The present findings suggest that PEI-PEG nanocarrier-mediated XIAP gene transfection results in XIAP expression in the cochlea, prevents damage to cochlear spiral ganglion cells, and protects hearing.

  15. Synthesis and characterization of gold nanotube/nanowire-polyurethane composite based on castor oil and polyethylene glycol.

    Science.gov (United States)

    Ganji, Yasaman; Kasra, Mehran; Salahshour Kordestani, Soheila; Bagheri Hariri, Mohiedin

    2014-09-01

    Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil-polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane-GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell attachment of polyurethane. Higher crosslink density and better cell attachment and proliferation were observed in polyurethane containing 50 ppm GNT/NW. The results revealed that GNT/NW formed hydrogen bonding with the polyurethane matrix and improved the thermomechanical properties of nanocomposites. Compared with pure PU, better cellular attachment on polyurethane-GNT/NW composites was observed resulting from the improved surface properties of composites.

  16. Polyethylene glycol-based hydrogels for controlled release of the antimicrobial subtilosin for prophylaxis of bacterial vaginosis.

    Science.gov (United States)

    Sundara Rajan, Sujata; Cavera, Veronica L; Zhang, Xiaoping; Singh, Yashveer; Chikindas, Michael L; Sinko, Patrick J

    2014-05-01

    Current treatment options for bacterial vaginosis (BV) have been shown to be inadequate at preventing recurrence and do not provide protection against associated infections, such as that with HIV. This study examines the feasibility of incorporating the antimicrobial peptide subtilosin within covalently cross-linked polyethylene glycol (PEG)-based hydrogels for vaginal administration. The PEG-based hydrogels (4% and 6% [wt/vol]) provided a two-phase release of subtilosin, with an initial rapid release rate of 4.0 μg/h (0 to 12 h) followed by a slow, sustained release rate of 0.26 μg/h (12 to 120 h). The subtilosin-containing hydrogels inhibited the growth of the major BV-associated pathogen Gardnerella vaginalis with a reduction of 8 log10 CFU/ml with hydrogels containing ≥15 μg entrapped subtilosin. In addition, the growth of four common species of vaginal lactobacilli was not significantly inhibited in the presence of the subtilosin-containing hydrogels. The above findings demonstrate the potential application of vaginal subtilosin-containing hydrogels for prophylaxis of BV.

  17. Poly(ethylene glycol)-containing hydrogels modulate α-defensin release from polymorphonuclear leukocytes and monocyte recruitment.

    Science.gov (United States)

    Lieberthal, Tyler Jacob; Cohen, Hannah Caitlin; Kao, W John

    2015-12-01

    Polymorphonuclear leukocytes (PMNs) release granule proteins as the first line of defense against bacteria and set up chemotactic gradients that result in monocyte infiltration to the site of injury. Although well established, the role of biomaterials in regulating adherent PMN degranulation and subsequent PMN-monocyte paracrine interactions is less clear. The aim of this study was to determine how biomaterials affect the degranulation of selected biomarkers and downstream monocyte adhesion and transendothelial migration. Poly(ethylene glycol) (PEG)-containing hydrogels (PEG and an interpenetrating network of PEG and gelatin) promote the release of the α-defensins human neutrophil peptides 1-3, but not azurocidin or monocyte chemotactic protein-1. Although human neutrophil peptides 1-3 are monocyte chemoattractants, no subsequent effects on monocyte transmigration are observed in static conditions. Under flow conditions, monocyte adhesion on human umbilical vein endothelial cells stimulated with tumor necrosis factor-α is elevated in the presence of granule proteins from PMNs adherent on polydimethylsiloxane, but not from PMNs cultured on PEG hydrogels. These results suggest that PEG promotes PMN antimicrobial capacity without enhanced monocyte recruitment.

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

    Science.gov (United States)

    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 (1)H-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 and their particle sizes were less than 100 nm. In a (1)H-NMR study in D2O, specific peaks of PEG solely appeared while peaks of PHO disappeared, indicating that nanoparticles have core-shell structures. The higher M.W. of PEG decreased loading efficiency and particle size. The higher drug feeding increased drug contents and average size of nanoparticles. In the drug release study, the higher M.W. of PEG block induced the acceleration of drug release rate. The increase in drug contents induced the slow release rate of drug. In an antitumor activity study in vitro, paclitaxel nanoparticles have practically similar anti-proliferation activity against HCT116 human colon carcinoma cells. In an in vivo animal study using HCT116 colon carcinoma cell-bearing mice, paclitaxel nanoparticles have enhanced antitumor activity compared to paclitaxel itself. Therefore, paclitaxel-incorporated nanoparticles of PHO/PEG block copolymer are a promising vehicle for antitumor drug delivery. PMID:25288916

  19. Influence of the molecular design on the antifouling performance of poly(ethylene glycol) monolayers grafted on (111) Si.

    Science.gov (United States)

    Perez, Emmanuel; Lahlil, Khalid; Rougeau, Cyrille; Moraillon, Anne; Chazalviel, Jean-Noël; Ozanam, François; Gouget-Laemmel, Anne Chantal

    2012-10-16

    Various poly(ethylene glycol) monomethyl ether moieties were grafted onto hydrogenated silicon surfaces in order to investigate the influence of the molecular design on the antifouling performance of such coatings. The grafted chains were either oligo(ethylene oxide) chains (EG)(n)OMe bound to silicon via Si-O-C covalent bonds, or hybrid alkyl/oligo(ethylene oxide) chains C(p)(EG)(n)OMe bound via Si-C covalent bonds (from home-synthesized precursors). Quantitative IR spectroscopy gave the molecular coverage of the grafted layers, and AFM imaging demonstrated that a proper surfactinated rinse yields C(p)(EG)(n)OMe layers free of unwanted residues. The protein-repellent character of these grafted layers (here, toward BSA) was studied by IR and AFM imaging. C(p)(EG)(n)OMe layers exhibit a lower surface concentration than (EG)(n)OMe layers, because of the presence of a solvent in the grafting solution; they however demonstrate high resistance against BSA adsorption for high values of the n/p ratio and a higher stability than (EG)(n)OMe. This behavior is consistently explained by the poor ordering capability of the alkyl part of the layer, contrary to what is observed for similar layers on Au, and the key role of an entangled arrangement of the ethylene oxide chains which forms when these chains are long enough. PMID:22988984

  20. Synthesis and characterization of gold nanotube/nanowire–polyurethane composite based on castor oil and polyethylene glycol

    International Nuclear Information System (INIS)

    Gold nanotubes/nanowires (GNT/NW) were synthesized by using the template-assisted electrodeposition technique and mixed with castor oil–polyethylene glycol based polyurethane (PU) to fabricate porous composite scaffolds for biomedical application. 100 and 50 ppm of GNT/NW were used to synthesize composites. The composite scaffolds were characterized by Fourier transform infrared spectroscopy, dynamic mechanical thermal analysis, differential scanning calorimetry, and scanning electron microscopy. Cell attachment on polyurethane–GNT/NW composites was investigated using fat-derived mesenchymal stem cells. Addition of 50 or 100 ppm GNT/NW had significant effects on thermal, mechanical, and cell attachment of polyurethane. Higher crosslink density and better cell attachment and proliferation were observed in polyurethane containing 50 ppm GNT/NW. The results revealed that GNT/NW formed hydrogen bonding with the polyurethane matrix and improved the thermomechanical properties of nanocomposites. Compared with pure PU, better cellular attachment on polyurethane–GNT/NW composites was observed resulting from the improved surface properties of composites. - Highlights: • Polyurethane–gold nanotubes/nanowires (GNT/NWs) composites were synthesized. • Tan δ, E′ and E″ were increased upon addition of 50 ppm of GNT/NW. • Better cell attachment was observed in composites containing 50 ppm of GNT/NW. • GNT/NWs can make a bridge between the pores of the porous polymeric scaffolds. • GNT/NWs increased the crosslink density of the polymeric matrix

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

    Science.gov (United States)

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

    2013-07-01

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

  2. A highly sensitive biosensor for tumor maker alpha fetoprotein based on poly(ethylene glycol) doped conducting polymer PEDOT.

    Science.gov (United States)

    Cui, Min; Song, Zhiling; Wu, Yumin; Guo, Bing; Fan, Xiaojian; Luo, Xiliang

    2016-05-15

    Biocompatible polymers, such as poly(ethylene glycol) (PEG), are of great significance in the development of bio-interfaces and biosensors, as they possess excellent biocompatibility and are easy for modification. A novel highly biocompatible polymer composite was synthesized herein through electrochemical polymerization of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and a PEG derivative, 4-arm PEG terminated with thiol groups. The electrodeposited conducting polymer composite of PEG doped PEDOT (PEDOT/PEG) exhibited flake-like nanostructure, large surface area and outstanding stability. In order to further immobilize antibodies, gold nanoparticles (AuNPs) were introduced to the PEDOT/PEG composite surface through their unique interaction with the thiol groups. AuNPs modified PEDOT/PEG provided a desirable support for the immobilization of various biomolecules such as antibodies for alpha fetoprotein (AFP), a vital tumor biomarker for liver cancer. The fabricated AFP biosensor demonstrated favorable selectivity, high sensitivity, and ultralow detection limit. Furthermore, owing to the presence of PEG polymers that are highly hydrophilic, such AuNPs/PEDOT/PEG based AFP biosensor also exhibited good anti-fouling ability, and it was capable of assaying target AFP in 10% (V/V) human serum samples, indicating highly feasible potential for clinical diagnosis. PMID:26774088

  3. Synthesis of polycarbonate-r-polyethylene glycol copolymer for templated synthesis of mesoporous TiO2 films.

    Science.gov (United States)

    Patel, Rajkumar; Kim, Jinkyu; Lee, Chang Soo; Kim, Jong Hak

    2014-12-01

    We synthesized a novel polycarbonate Z-r-polyethylene glycol (PCZ-r-PEG) copolymer by solution polycondensation. Successful synthesis of PCZ-r-PEG copolymer was confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC), and transmission electron microscopy (TEM). PCZ-r-PEG copolymer was used as a structure-directing agent for fabrication of mesoporous thin film containing a titanium dioxide (TiO2) layer. To control the porosity of the resultant inorganic layer, the ratio of titanium(IV) isopropoxide (TTIP) to PCZ-r-PEG copolymer was varied. The structure and porosity of the resulting mesoporous films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Mesoporous TiO2 films fabricated on an F-doped tin oxide (FTO) surface were used as photoanodes for quasi-solid-state dye-sensitized solar cells (qssDSSCs). The highest efficiency achieved was 3.3% at 100 mW/cm2 for a film thickness of 750 nm, which is high considering the thickness of TiO2 film, indicating the importance of the structure-directing agent. PMID:25971065

  4. Formation and characterization of chitosan-polylacticacid-polyethylene glycol-gelatin nanoparticles: a novel biosystem for controlled drug delivery.

    Science.gov (United States)

    Rajan, M; Raj, V

    2013-10-15

    Chitosan (CS)-polylacticacid (PLA)-polyethylene glycol (PEG)-gelatin (G) nanoparticles, a novel drug vehicle for the controlled release of an antitubercluosis drug, rifampicin (RIF) was developed and its chemical and biochemical activities were studied by various standard methods. The designed carriers CS, PEG and G nanoparticles were prepared by emulsion solvent evaporation technique, and then used for entrapping RIF. Linking was confirmed by FTIR spectroscopy. The surface morphology of the nanoparticles was studied using scanning electron microscope and polarizing microscope. The influence of process variables, on particle size, zeta potential and matrix entrapment of RIF was studied. The encapsulation and loading capacity were evaluated, and an in vitro release of RIF was assessed using the dialysis method. The effect of nanoencapsulation of RIF on the antibacterial activity of RIF against Mycobacterium strains was evaluated. The preliminary results clearly suggested that the cross linked CS-PLA-PEG-G matrix may be a potential polymeric carrier for controlled delivery of RIF. PMID:23987433

  5. Superporous Poly(ethylene glycol) Diacrylate Cryogel with a Defined Elastic Modulus for Prostate Cancer Cell Research.

    Science.gov (United States)

    Göppert, Bettina; Sollich, Thomas; Abaffy, Paul; Cecilia, Angelica; Heckmann, Jan; Neeb, Antje; Bäcker, Anne; Baumbach, Tilo; Gruhl, Friederike J; Cato, Andrew C B

    2016-08-01

    The physical and mechanical properties of the tumor microenvironment are crucial for the growth, differentiation and migration of cancer cells. However, such microenvironment is not found in the geometric constraints of 2D cell culture systems used in many cancer studies. Prostate cancer research, in particular, suffers from the lack of suitable in vitro models. Here a 3D superporous scaffold is described with thick pore walls in a mechanically stable and robust architecture to support prostate tumor growth. This scaffold is generated from the cryogelation of poly(ethylene glycol) diacrylate to produce a defined elastic modulus for prostate tumor growth. Lymph node carcinoma of the prostate (LNCaP) cells show a linear growth over 21 d as multicellular tumor spheroids in such a scaffold with points of attachments to the walls of the scaffold. These LNCaP cells respond to the growth promoting effects of androgens and demonstrate a characteristic cytoplasmic-nuclear translocation of the androgen receptor and androgen-dependent gene expression. Compared to 2D cell culture, the expression or androgen response of prostate cancer specific genes is greatly enhanced in the LNCaP cells in this system. This scaffold is therefore a powerful tool for prostate cancer studies with unique advantages over 2D cell culture systems. PMID:27240250

  6. Self-assembly of core-polyethylene glycol-lipid shell (CPLS) nanoparticles and their potential as drug delivery vehicles

    Science.gov (United States)

    Shen, Zhiqiang; Loe, David T.; Awino, Joseph K.; Kröger, Martin; Rouge, Jessica L.; Li, Ying

    2016-08-01

    Herein a new multifunctional formulation, referred to as a core-polyethylene glycol-lipid shell (CPLS) nanoparticle, has been proposed and studied in silico via large scale coarse-grained molecular dynamics simulations. A PEGylated core with surface tethered polyethylene glycol (PEG) chains is used as the starting configuration, where the free ends of the PEG chains are covalently bonded with lipid molecules (lipid heads). A complete lipid bilayer is formed at the surface of the PEGylated particle core upon addition of free lipids, driven by the hydrophobic properties of the lipid tails, leading to the formation of a CPLS nanoparticle. The self-assembly process is found to be sensitive to the grafting density and molecular weight of the tethered PEG chains, as well as the amount of free lipids added. At low grafting densities the assembly of CPLS nanoparticles cannot be accomplished. As demonstrated by simulations, a lipid bud/vesicle can be formed on the surface when an excess amount of free lipids is added at high grafting density. Therefore, the CPLS nanoparticles can only be formed under appropriate conditions of both PEG and free lipids. The CPLS nanoparticle has been recognized to be able to store a large quantity of water molecules, particularly with high molecular weight of PEG chains, indicating its capacity for carrying hydrophilic molecules such as therapeutic biomolecules or imaging agents. Under identical size and surface chemistry conditions of a liposome, it has been observed that the CPLS particle can be more efficiently wrapped by the lipid membrane, indicating its potential for a greater efficiency in delivering its hydrophilic cargo. As a proof-of-concept, the experimental realization of CPLS nanoparticles is explicitly demonstrated in this study. To test the capacity of the CPLS to store small molecule cargo a hydrophilic dye was successfully encapsulated in the particles' water soluble layer. The results of this study show the power and

  7. Complexes of Imidazole with Poly(ethylene glycol) as a Corrosion Inhibitor for Carbon Steel in Sulphuric Acid

    Science.gov (United States)

    Salimi, Saeed; Nasr-Esfahani, Mojtaba; Umoren, Saviour A.; Saebnoori, Ehsan

    2015-12-01

    The inhibiting action of polyethylene glycol and imidazole (PEG/IMZ)) complexes prepared by a simple deprotonation procedure on carbon steel corrosion in 0.5 mol/L sulphuric acid was evaluated using the weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques complemented by surface analysis using scanning electron microscopy. The inhibiting effect of the PEG/IMZ complexes on carbon steel corrosion was compared with the non-complex forms. Results obtained show that PEG/IMZ complex is a very effective corrosion inhibitor of carbon steel in the acid environment. The inhibition efficiency increased with the increase in the temperature and also with increasing percentage of imidazole in the complex. Corrosion inhibition occurs by virtue of adsorption of PEG/IMZ complexes on the steel surface which was found to follow the Temkin adsorption isotherm model. The PEG/IMZ complexes function as a mixed-type inhibitor. Results from all the methods employed are in a reasonably good agreement.

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

    Science.gov (United States)

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

    2015-03-01

    The development of advanced scaffolds that recapitulate the anisotropic mechanical behavior and biological functions of the extracellular matrix in leaflets would be transformative for heart valve tissue engineering. In this study, anisotropic mechanical properties were established in poly(ethylene glycol) (PEG) hydrogels by crosslinking stripes of 3.4 kDa PEG diacrylate (PEGDA) within 20 kDa PEGDA base hydrogels using a photolithographic patterning method. Varying the stripe width and spacing resulted in a tensile elastic modulus parallel to the stripes that was 4.1-6.8 times greater than that in the perpendicular direction, comparable to the degree of anisotropy between the circumferential and radial orientations in native valve leaflets. Biomimetic PEG-peptide hydrogels were prepared by tethering the cell-adhesive peptide RGDS and incorporating the collagenase-degradable peptide PQ (GGGPQG↓IWGQGK) into the polymer network. The specific amounts of RGDS and PEG-PQ within the resulting hydrogels influenced the elongation, de novo extracellular matrix deposition and hydrogel degradation behavior of encapsulated valvular interstitial cells (VICs). In addition, the morphology and activation of VICs grown atop PEG hydrogels could be modulated by controlling the concentration or micro-patterning profile of PEG-RGDS. These results are promising for the fabrication of PEG-based hydrogels using anatomically and biologically inspired scaffold design features for heart valve tissue engineering. PMID:25433168

  9. Realizing Highly Efficient Inverted Photovoltaic Cells by Combination of Nonconjugated Small-Molecule Zwitterions with Polyethylene Glycol.

    Science.gov (United States)

    Zhang, Wenjun; Song, Changjian; Liu, Xiaohui; Fang, Junfeng

    2016-07-20

    Organic ionic materials have been reported to be efficient cathode interlayer (CIL) materials in polymer solar cells (PSCs); however, most of them are employed in conventional PSCs. For an inverted structural device which has better stability, the efficiency is still far from expectation and the report is also limited. In this study, by using nonconjugated zwitterions as the CIL and inverted structure, the power conversion efficiency (PCE) is ∼6%, though the PCE can reach 9.14% in the conventional device. By introducing polyethylene glycol (PEG) into the zwitterions, the PCE of the inverted PSCs was improved ∼33% and reached ∼8% mainly because of the enhancement of the open-circuit voltage (Voc) and fill factor (FF). Further research on the device parameters, work functions, morphology of indium tin oxide (ITO) with various CILs, and recombination resistance of the devices indicated that PEG + zwitterion induced not only a lower work function of ITO but also a more uniform morphology of CILs with less contact of the photoactive layer with ITO, which induced suppressed charge recombination and a higher Voc and FF. Enhanced ability in interface modification of PEG + zwitterion CILs displayed a simple and feasible approach to elevate the performance of inverted PSCs with ionic CILs. PMID:27355561

  10. Surface chemistry and size influence the release of model therapeutic nanoparticles from poly(ethylene glycol) hydrogels

    International Nuclear Information System (INIS)

    Nanoparticles have emerged as promising therapeutic and diagnostic tools, due to their unique physicochemical properties. The specific core and surface chemistries, as well as nanoparticle size, play critical roles in particle transport and interaction with biological tissue. Localized delivery of therapeutics from hydrogels is well established, but these systems generally release molecules with hydrodynamic radii less than ∼5 nm. Here, model nanoparticles with biologically relevant surface chemistries and diameters between 10 and 35 nm are analyzed for their release from well-characterized hydrogels. Functionalized gold nanoparticles or quantum dots were encapsulated in three-dimensional poly(ethylene glycol) hydrogels with varying mesh size. Nanoparticle size, surface chemistry, and hydrogel mesh size all influenced the release of particles from the hydrogel matrix. Size influenced nanoparticle release as expected, with larger particles releasing at a slower rate. However, citrate-stabilized gold nanoparticles were not released from hydrogels. Negatively charged carboxyl or positively charged amine-functionalized quantum dots were released from hydrogels at slower rates than neutrally charged PEGylated nanoparticles of similar size. Transmission electron microscopy images of gold nanoparticles embedded within hydrogel sections demonstrated uniform particle distribution and negligible aggregation, independent of surface chemistry. The nanoparticle-hydrogel interactions observed in this work will aid in the development of localized nanoparticle delivery systems.

  11. Effective isolation of exosomes with polyethylene glycol from cell culture supernatant for in-depth proteome profiling.

    Science.gov (United States)

    Weng, Yejing; Sui, Zhigang; Shan, Yichu; Hu, Yechen; Chen, Yuanbo; Zhang, Lihua; Zhang, Yukui

    2016-08-01

    Exosomes are secreted nanovesicles shed by almost all kinds of cells. Recently, increased interest has been focused on these extracellular vesicles as natural carriers transporting biological contents for intercellular communication. However, current isolation techniques, such as ultracentrifugation, are not convenient and often require specialized equipment. Herein, we describe a polyethylene glycol (PEG)-based approach, which could permit facile, low-cost and effective isolation of exosomes from cell culture supernatant. High-resolution electron microscopes clearly visualized the size and morphology of isolated exosome aggregates, implying the mechanism of PEG-based precipitation. Combined with tandem mass spectrometry analysis, 6299 protein groups encoded by 5120 genes were successfully characterized from HeLa cell culture supernatant, including numerous exosome proteins which could overlap 97% of the Top 100 exosome marker proteins recorded in the ExoCarta database, as well as a series of low-abundance cytokines and biomarkers. Furthermore, we found a higher ratio of neo-cleavage sites in proteins identified from exosomes compared with cellular proteins, revealing the potential roles of exosomes in accumulation and transportation of protein degradation intermediates. PMID:27229443

  12. Comparative bone uptake study of alendronate sodium from vaginal suppositories prepared with polyethylene glycol and massa estarinum bases

    Directory of Open Access Journals (Sweden)

    Derya İlem-Özdemir

    2013-09-01

    Full Text Available The aim of this study was to compare the bone uptake of alendronate sodium (ALD from vaginal suppositories prepared with massa estarinum AB (ME and polyethylene glycol 1500 (PEG bases. For this purpose, ALD was radiolabeled with 99mTecnetium Pertechnetate (99mTc by direct method. Radiochemical purity and stability of 99mTc-ALD was performed with chromatographic studies. 99mTc-ALD containing suppositories were prepared with ME and PEG bases. Physical properties of suppositories were evaluated. The physicochemical diffusion study was carried out to compare the release of ALD from different suppository bases. The bone uptake of 99mTc-ALD was observed by gamma scintigraphy studies. 99mTc-ALD containing suppositories were administrated to rabbits via vaginal route. The scintigraphic images were obtained with a gamma camera at different time intervals up to 240 minutes. According to our studies, radiochemical purity of 99mTc-ALD was observed more than 95% up to 6 hours. At 240 minutes of physicochemical diffusion studies, released ALD has 0.620 ± 0.091 mm and 10.465 ± 0.651 mm diameter zone from ME and PEG base suppositories respectively. According to the gamma scintigraphy studies, although no bone uptake observed after ME suppositories application, rabbit’s bones were clearly visible after PEG suppositories applied. The results of physicochemical diffusion and gamma scintigraphy studies were found compatible in each other

  13. Feed intake and growth performance of growing pigs fed on Acacia tortilis leaf meal treated with polyethylene glycol.

    Science.gov (United States)

    Hlatini, Vuyisa Andries; Khanyile, Mbongeni; Zindove, Titus Jairus; Chimonyo, Michael

    2016-03-01

    The objective of the study was to determine the response in feed intake and performance of pigs fed on incremental levels of polyethylene glycol (PEG). Forty-eighty male F1 hybrid pigs were randomly allotted to six diets containing 0, 5, 10, 15, 20, and 25 g/kg of PEG, respectively. Acacia tortilis leaf meal was included at a rate of 150 g/kg. Each diet was offered ad libitum to eight pigs in individual pens. Average daily feed intake (ADFI), scaled feed intake (SFI), average daily gain (ADG), and gain to feed ratio (G:F) were determined weekly. The ADG showed a linear response to PEG (p  0.05). The regression equations and R(2) values were as follows: ADFI y = 0.0008x(2) - 00086x + 1.2339 (R(2) = 0.96), SFI y = 0.0147x(2) - 0.2349x + 40.096 (R(2) = 0.95), and G:F ratio y = 0.0002x(2) - 0.0017x + 0.5168 (R(2) = 0.56). The ADFI, SFI, and ADG increased as weeks of feeding progressed (p economic benefit of using PEG depend on cost of labor, availability of Acacia, costs of harvesting together with processing, and acceptability of the pork. PMID:26894498

  14. Thermoplastic Epoxide Resin in the Presence of Polyethylene Glycol as Hot-melt Adhesive in Clean Technology

    Directory of Open Access Journals (Sweden)

    G.S. Mukherjee

    2004-04-01

    Full Text Available Pollution caused by the process involving handling of solvents is considered as one of the most serious ecological problems. In this perspective, thermoplastic epoxide resins were synthesized from the controlled reaction of bisphenol A, epichlorohydrine, and 3,5 dimethylaniline with a view to prepare ingredients for hot melt adhesive was designated as HMA/(Subscript35' Addition of polyethylene glycol (20 Wt per cent of molecular weight 6000 (PEG6K in the blend was found to be optimum towards providing maximum tensile lap shear strength with reference to aluminium/adhesive/aluminium bonding with a value of 5.05MPa. The matrix of the blend remains optically transparent till the content of PEG6K remains up to 20 Wt per cent; however beyond 20 Wt percent of PEG6k, the matrix becomes opaque with the appearance of spherulities due to presence of excess PEG6K in the blend. Interestingly, blends containing <= 20 Wt percent PEG6K showed no endotherm below 100 (DegreeC even though the melting point of pristine PEG6K is 55 (degreeC. FTIR data revealed the interactive role of PEG6K with the epoxide resin.

  15. Effect of polyethylene glycol conjugation on conformational and colloidal stability of a monoclonal antibody antigen-binding fragment (Fab').

    Science.gov (United States)

    Roque, Cristopher; Sheung, Anthony; Rahman, Nausheen; Ausar, S Fernando

    2015-02-01

    We have investigated the effects of site specific "hinge" polyethylene glycol conjugation (PEGylation) on thermal, pH, and colloidal stability of a monoclonal antibody antigen-binding fragment (Fab') using a variety of biophysical techniques. The results obtained by circular dichroism (CD), ultraviolet (UV) absorbance, and fluorescence spectroscopy suggested that the physical stability of the Fab' is maximized at pH 6-7 with no apparent differences due to PEGylation. Temperature-induced aggregation experiments revealed that PEGylation was able to increase the transition temperature, as well as prevent the formation of visible and subvisible aggregates. Statistical comparison of the three-index empirical phase diagram (EPD) revealed significant differences in thermal and pH stability signatures between Fab' and PEG-Fab'. Upon mechanical stress, micro-flow imaging (MFI) and measurement of the optical density at 360 nm showed that the PEG-Fab' had significantly higher resistance to surface-induced aggregation compared to the Fab'. Analysis of the interaction parameter, kD, indicated repulsive intermolecular forces for PEG-Fab' and attractive forces for Fab'. In conclusion, PEGylation appears to protect Fab' against thermal and mechanical stress-induced aggregation, likely due to a steric hindrance mechanism.

  16. Acute toxicity of polyethylene glycol p-isooctylphenol ether in Syrian hamsters exposed by inhalation or bronchopulmonary lavage

    Energy Technology Data Exchange (ETDEWEB)

    Damon, E.G. (Inhalation Toxicology Research Inst., Albuquerque, NM); Halliwell, W.H.; Henderson, T.R.; Mokler, B.V.; Jones, R.K.

    1982-01-01

    Dose-response studies were conducted with Syrian hamsters exposed to polyethylene glycol p-isooctylphenyl ether (Triton X-100) via inhalation or bronchopulmonary lavage. Syrian hamsters were exposed to an aerosol of Triton X-100 with a mass median aerodynamic diameter of 1.5 ..mu..m and a concentration of 3.0 mg/liter. Estimated initial lung burdens of Triton X-100 ranged from 800 to 3100 ..mu..g. Hamsters were lavaged with concentrations of Triton X-100 ranging from 0.01 to 0.10% in isotonic saline resulting in initial lung burdens of Triton X-100 that ranged from 300 to 3200 ..mu..g. The LD50/7 values were 1700 ..mu..g (1300 to 2100 ..mu..g, 95% confidence limits) for the inhalation study and 2100 (1900 to 2700) ..mu..g for the lavage study. The difference between the LD50/7 values for the two methods of exposure was not significant. However, histopathological examination revealed differences in the nature and distribution of pathologic changes observed in animals exposed by the two routes of administration. Animals exposed by inhalation died as a result of ulcerative laryngitis and laryngeal edema with only minimal pulmonary pathologic alterations. Animals exposed by lavage, where the larynx was not exposed to Triton X-100, died from pulmonary edema and acute exudative pneumonia. These results demonstrate the need for careful selection of exposure methods to meet the specific objectives of a toxicology study.

  17. A highly sensitive biosensor for tumor maker alpha fetoprotein based on poly(ethylene glycol) doped conducting polymer PEDOT.

    Science.gov (United States)

    Cui, Min; Song, Zhiling; Wu, Yumin; Guo, Bing; Fan, Xiaojian; Luo, Xiliang

    2016-05-15

    Biocompatible polymers, such as poly(ethylene glycol) (PEG), are of great significance in the development of bio-interfaces and biosensors, as they possess excellent biocompatibility and are easy for modification. A novel highly biocompatible polymer composite was synthesized herein through electrochemical polymerization of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and a PEG derivative, 4-arm PEG terminated with thiol groups. The electrodeposited conducting polymer composite of PEG doped PEDOT (PEDOT/PEG) exhibited flake-like nanostructure, large surface area and outstanding stability. In order to further immobilize antibodies, gold nanoparticles (AuNPs) were introduced to the PEDOT/PEG composite surface through their unique interaction with the thiol groups. AuNPs modified PEDOT/PEG provided a desirable support for the immobilization of various biomolecules such as antibodies for alpha fetoprotein (AFP), a vital tumor biomarker for liver cancer. The fabricated AFP biosensor demonstrated favorable selectivity, high sensitivity, and ultralow detection limit. Furthermore, owing to the presence of PEG polymers that are highly hydrophilic, such AuNPs/PEDOT/PEG based AFP biosensor also exhibited good anti-fouling ability, and it was capable of assaying target AFP in 10% (V/V) human serum samples, indicating highly feasible potential for clinical diagnosis.

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    Arif Hasan Khan Robin

    2015-10-01

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

  20. Nonchromatographic radioimmunoassay of plasma 11-deoxycortisol, for use in the metyrapone test, with polyethylene glycol as the precipitant

    International Nuclear Information System (INIS)

    We have developed a simple, reliable radioimmunoassay for plasma 11-deoxycortisol. The method does not require chromatography but instead makes use of a simple extraction procedure which, in combination with the antibody characteristics, is highly specific for the metyrapone test. Polyethylene glycol was used to separate free and antibody-bound steroid. The smallest amount measurable is 15 pg (2.0 μg/liter of plasma). The method is shown to be precise and accurate. Intra-assay precision of the method for two plasma pools was 26.7 +- 2.5 μg/liter (CV = 9.4 percent) and 61.2 +- 3.7 μg/liter (CV = 6.0 percent). The respective inter-assay precision was 27.0 +- 1.7 μg/liter (CV = 6.3 percent) and 59.9 +-- 2+3 G/liter (CV = 3.8 percent). The validity of the assay was further verified by evaluating the plasma 11-deoxycortisol response to metyrapone administration. The relative simplicity of the method and the commercial availability of all reagents, including antisera, makes this radioimmunoassay procedure practical for use in clinical laboratories. (auth)

  1. Protein adsorption is required for stealth effect of poly(ethylene glycol)- and poly(phosphoester)-coated nanocarriers

    Science.gov (United States)

    Schöttler, Susanne; Becker, Greta; Winzen, Svenja; Steinbach, Tobias; Mohr, Kristin; Landfester, Katharina; Mailänder, Volker; Wurm, Frederik R.

    2016-04-01

    The current gold standard to reduce non-specific cellular uptake of drug delivery vehicles is by covalent attachment of poly(ethylene glycol) (PEG). It is thought that PEG can reduce protein adsorption and thereby confer a stealth effect. Here, we show that polystyrene nanocarriers that have been modified with PEG or poly(ethyl ethylene phosphate) (PEEP) and exposed to plasma proteins exhibit a low cellular uptake, whereas those not exposed to plasma proteins show high non-specific uptake. Mass spectrometric analysis revealed that exposed nanocarriers formed a protein corona that contains an abundance of clusterin proteins (also known as apolipoprotein J). When the polymer-modified nanocarriers were incubated with clusterin, non-specific cellular uptake could be reduced. Our results show that in addition to reducing protein adsorption, PEG, and now PEEPs, can affect the composition of the protein corona that forms around nanocarriers, and the presence of distinct proteins is necessary to prevent non-specific cellular uptake.

  2. Realizing Highly Efficient Inverted Photovoltaic Cells by Combination of Nonconjugated Small-Molecule Zwitterions with Polyethylene Glycol.

    Science.gov (United States)

    Zhang, Wenjun; Song, Changjian; Liu, Xiaohui; Fang, Junfeng

    2016-07-20

    Organic ionic materials have been reported to be efficient cathode interlayer (CIL) materials in polymer solar cells (PSCs); however, most of them are employed in conventional PSCs. For an inverted structural device which has better stability, the efficiency is still far from expectation and the report is also limited. In this study, by using nonconjugated zwitterions as the CIL and inverted structure, the power conversion efficiency (PCE) is ∼6%, though the PCE can reach 9.14% in the conventional device. By introducing polyethylene glycol (PEG) into the zwitterions, the PCE of the inverted PSCs was improved ∼33% and reached ∼8% mainly because of the enhancement of the open-circuit voltage (Voc) and fill factor (FF). Further research on the device parameters, work functions, morphology of indium tin oxide (ITO) with various CILs, and recombination resistance of the devices indicated that PEG + zwitterion induced not only a lower work function of ITO but also a more uniform morphology of CILs with less contact of the photoactive layer with ITO, which induced suppressed charge recombination and a higher Voc and FF. Enhanced ability in interface modification of PEG + zwitterion CILs displayed a simple and feasible approach to elevate the performance of inverted PSCs with ionic CILs.

  3. Multiscale approach for the construction of equilibrated all-atom models of a poly(ethylene glycol)-based hydrogel.

    Science.gov (United States)

    Li, Xianfeng; Murthy, N Sanjeeva; Becker, Matthew L; Latour, Robert A

    2016-06-24

    A multiscale modeling approach is presented for the efficient construction of an equilibrated all-atom model of a cross-linked poly(ethylene glycol) (PEG)-based hydrogel using the all-atom polymer consistent force field (PCFF). The final equilibrated all-atom model was built with a systematic simulation toolset consisting of three consecutive parts: (1) building a global cross-linked PEG-chain network at experimentally determined cross-link density using an on-lattice Monte Carlo method based on the bond fluctuation model, (2) recovering the local molecular structure of the network by transitioning from the lattice model to an off-lattice coarse-grained (CG) model parameterized from PCFF, followed by equilibration using high performance molecular dynamics methods, and (3) recovering the atomistic structure of the network by reverse mapping from the equilibrated CG structure, hydrating the structure with explicitly represented water, followed by final equilibration using PCFF parameterization. The developed three-stage modeling approach has application to a wide range of other complex macromolecular hydrogel systems, including the integration of peptide, protein, and/or drug molecules as side-chains within the hydrogel network for the incorporation of bioactivity for tissue engineering, regenerative medicine, and drug delivery applications.

  4. Enzymatically-responsive pro-angiogenic peptide-releasing poly(ethylene glycol) hydrogels promote vascularization in vivo.

    Science.gov (United States)

    Van Hove, Amy H; Burke, Kathleen; Antonienko, Erin; Brown, Edward; Benoit, Danielle S W

    2015-11-10

    Therapeutic angiogenesis holds great potential for a myriad of tissue engineering and regenerative medicine approaches. While a number of peptides have been identified with pro-angiogenic behaviors, therapeutic efficacy is limited by poor tissue localization and persistence. Therefore, poly(ethylene glycol) hydrogels providing sustained, enzymatically-responsive peptide release were exploited for peptide delivery. Two pro-angiogenic peptide drugs, SPARC113 and SPARC118, from the Secreted Protein Acidic and Rich in Cysteine, were incorporated into hydrogels as crosslinking peptides flanked by matrix metalloproteinase (MMP) degradable substrates. In vitro testing confirmed peptide drug bioactivity requires sustained delivery. Furthermore, peptides retain bioactivity with residual MMP substrates present after hydrogel release. Incorporation into hydrogels achieved enzymatically-responsive bulk degradation, with peptide release in close agreement with hydrogel mass loss and released peptides retaining bioactivity. Interestingly, SPARC113 and SPARC118-releasing hydrogels had significantly different degradation time constants in vitro (1.16 and 8.77×10(-2) h(-1), respectively), despite identical MMP degradable substrates. However, upon subcutaneous implantation, both SPARC113 and SPARC118 hydrogels exhibited similar degradation constants of ~1.45×10(-2) h(-1), and resulted in significant ~1.65-fold increases in angiogenesis in vivo compared to controls. Thus, these hydrogels represent a promising pro-angiogenic approach for applications such as tissue engineering and ischemic tissue disorders.

  5. Isolation and characterization of a gene encoding a polyethylene glycol-induced cysteine protease in common wheat

    Indian Academy of Sciences (India)

    Qing-Wei Zang; Cai-Xiang Wang; Xu-Yan Li; Zhi-Ai Guo; Rui-Lian Jing; Jun Zhao; Xiao-Ping Chang

    2010-09-01

    Plant cysteine protease (CP) genes are induced by abiotic stresses such as drought, yet their functions remain largely unknown. We isolated the full-length cDNA encoding a Triticum aestivum CP gene, designated TaCP, from wheat by the rapid amplification of cDNA ends (RACE) method. Sequence analysis revealed that TaCP contains an open reading frame encoding a protein of 362 amino acids, which is 96% identical to barley cysteine protease HvSF42. The TaCP transcript level in wheat seedlings was upregulated during polyethylene glycol (PEG) stress, with a peak appearing around 12 h after treatment. TaCP expression level increased rapidly with NaCl treatment at 48 h. TaCP responded strongly to low temperature (4°C) treatment from 1 h post-treatment and reached a peak of about 40-fold at 72 h. However, it showed only a very slight response to abscisic acid (ABA). More than one copy of TaCP was present in each of the three genomes of hexaploid wheat and its diploid donors. TaCP fused with green fluorescent protein (GFP) was located in the plasma membrane of onion epidermis cells. Transgenic Arabidopsis plants overexpressing TaCP showed stronger drought tolerance and higher CP activity under water-stressed conditions than wild-type Arabidopsis plants. The results suggest that TaCP plays a role in tolerance to water deficit.

  6. Addition of Purified Tannin Sources and Polyethylene Glycol Treatment on Methane Emission and Rumen Fermentation in Vitro

    Directory of Open Access Journals (Sweden)

    A. Jayanegara

    2015-04-01

    Full Text Available The objectives of this experiment were (1 to observe the effects of purified tannins and polyethy-lene glycol (PEG on in vitro rumen fermentation and methanogenesis, and (2 to assess the accuracy of volatile fatty acid (VFA profiles in predicting methane emission. Hydrolysable and condensed tannins were extracted and purified from chestnut, sumach, mimosa and quebracho. Hay and concentrate mixture (70:30 w/w, 380 mg was incubated in Hohenheim glass syringe containing 10 mL rumen liquor + 20 mL buffer. The purified tannins were injected into the syringes at a concentration of 1.0 mg/mL each, either without or with PEG 6,000 addition in three replicates. Results revealed that a decrease of methane emission (20%-27% was observed when the purified tannins were added into basal diet as compared to control (P<0.05, and PEG addition increased methane emission (P<0.05. All purified tannins decreased total gas and total VFA production (P<0.05. The H2 recovery of the treatments ranged from 86.7% to 95.3%. Estimation of methane emission by using VFA profiles revealed an accurate result with a very low root mean square prediction error (1.75%. It is concluded that tannins mitigate methane emission while PEG neutralize such effect, and VFA profiles are accurate predictors of the emission.

  7. Fabrication of tethered carbon nanotubes in cellulose acetate/polyethylene glycol-400 composite membranes for reverse osmosis.

    Science.gov (United States)

    Sabir, Aneela; Shafiq, Muhammad; Islam, Atif; Sarwar, Afsheen; Dilshad, Muhammad Rizwan; Shafeeq, Amir; Zahid Butt, Muhammad Taqi; Jamil, Tahir

    2015-11-01

    In this study pristine multi-walled carbon nanotubes (MWCNTs) were surface engineered (SE) in strong acidic medium by oxidation purification method to form SE-MWCNT. Five different amount of SE-MWCNT ranging from 0.1 to 0.5 wt% were thoroughly and uniformly dispersed in cellulose acetate/polyethylene glycol (CA/PEG400) polymer matrix during synthesis of membrane by dissolution casting method. The structural analysis, surface morphology and roughness was carried out by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively, which showed that the dispersed SE-MWCNT was substantially tethered in CA/PEG400 polymer matrix membrane. The thermogravimetric analysis (TGA) of membranes also suggested some improvement in thermal properties with the addition of SE-MWCNT. Finally, the performance of these membranes was assessed for suitability in drinking water treatment. The permeation flux and salt rejection were determined by using indigenously fabricated reverse osmosis pilot plant with 1000 ppm NaCl feed solution. The results showed that the tethered SE-MWCNT/CA/PEG400 polymer matrix membrane, with strong SE-MWCNTs/polymer matrix interaction, improved the salt rejection performance of the membrane with the salt rejection of 99.8% for the highest content of SE-MWCNT.

  8. RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells

    OpenAIRE

    Nazli C; Ergenc TI; Yar Y; Acar HY; Kizilel S

    2012-01-01

    © 2012 Nazli et al, publisher and licensee Dove Medical Press Ltd. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited. International Journal of Nanomedicine 2012:7 1903–1920 International Journal of Nanomedicine RGDS-functionalized polyethylene glycol hydrogel-coated magnetic iron oxide nanoparticles enhance specific intracellular uptake by HeLa cells Caner Nazli1 Tugba Ipek Ergenc2 Yasemin Ya...

  9. Cancer Treatment: Superporous Poly(ethylene glycol) Diacrylate Cryogel with a Defined Elastic Modulus for Prostate Cancer Cell Research (Small 29/2016).

    Science.gov (United States)

    Göppert, Bettina; Sollich, Thomas; Abaffy, Paul; Cecilia, Angelica; Heckmann, Jan; Neeb, Antje; Bäcker, Anne; Baumbach, Tilo; Gruhl, Friederike J; Cato, Andrew C B

    2016-08-01

    On page 3985, F. J. Gruhl, A. C. B. Cato engineer superporous poly(ethylene glycol) diacrylate cryogels that mimic the stiffness of malignant prostate tissues for studies of prostate cancer cell growth and function. Cells grow in an anchorage-dependent manner in this scaffold for three weeks and respond to androgen and antiandrogen treatment. Compared to 2D cell culture system, androgen-dependent prostate target gene expression is highly regulated in this system. PMID:27477259

  10. Polyethylene Glycols as Efficient Media for Decarboxylative Nitration of α,β-Unsaturated Aromatic Carboxylic Acids by Ceric Ammonium Nitrate in Acetonitrile Medium: A Kinetic and Mechanistic Study

    OpenAIRE

    K.Ramesh; S. Shylaja; K. C. Rajanna; P. Giridhar Reddy; P. K. Saiprakash

    2013-01-01

    Polyethylene glycols (PEGs) were found to be efficient media for decarboxylative nitration of α,β-unsaturated aromatic carboxylic acids by ceric ammonium nitrate (CAN) in acetonitrile to give β-nitrostyrene derivatives. Kinetics of the reaction exhibited second order kinetics with a first order dependence on [CAN] and [substrate]. Reactions were too sluggish to be studied in the absence of PEG; therefore detailed kinetics were not taken up. Reaction times were reduced from 24 hrs to few hours...

  11. Experimental study of thermodynamic and transport properties of binary mixtures of poly(ethylene glycol) diacrylate and alcohols at different temperatures

    OpenAIRE

    Vuksanović Jelena M.; Radović Ivona R.; Šerbanović Slobodan P.; Kijevčanin Mirjana Lj.

    2015-01-01

    Experimental density r, refractive index nD and viscosity h data of three binary systems of poly(ethylene glycol) diacrylate (PEGDA) + ethanol, + 1-propanol, and + 1-butanol were measured at eight temperatures from (288.15 to 323.15) K, with temperature step of 5 K, and at atmospheric pressure. The experimental data were correlated as a function of PEGDA mole fraction and temperature. Densities and refractive indices of the investigated mixtures could be fi...

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

    Institute of Scientific and Technical Information of China (English)

    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.

  13. Two alternative dural sealing techniques in posterior fossa surgery: (Polylactide-co-glycolide self-adhesive resorbable membrane versus polyethylene glycol hydrogel

    Directory of Open Access Journals (Sweden)

    Marco Schiariti

    2014-01-01

    Conclusions: TPD seems to be a safe tool for use as an adjunct to standard dural closure in posterior fossa surgery, particularly in patients without pre- or post-oper ative risk factors, in those who did not develop hydrocephalus, and who underwent craniectomy. The CSF leak rate in TPD group was found to be lower or within the range of the more advanced alternative dural closure strategies, including polyethylene glycol (PEG-based sealant.

  14. Polyethylene glycol(PEG-400): An efficient and recyclable reaction medium for the synthesis of novel 1,5-benzodiazepines and their antimicrobial activity

    Institute of Scientific and Technical Information of China (English)

    Shankaraiah G. Konda; Baseer M. Shaikh; Sanjay A. Chavan; Bhaskar S. Dawane

    2011-01-01

    A new series of imidazole-containing 1,5-benzodiazepines have been synthesized by the condensation of chalcones with ophenylenediamine using piperidine in polyethylene glycol(PEG-400)as an efficient and green reaction solvent.The advantages of this protocol are environmental friendliness,easy work-up,high yields,mild reaction condition and avoidance of expensive catalyst.Furthermore,newly synthesized compounds were evaluated for their antimicrobial activity.

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  16. Thermodynamics of the sorption of organic compounds on polyethylene glycol 400-permethylated β-cyclodextrin stationary phase and its enantioselectivity in gas chromatography

    Science.gov (United States)

    Kuraeva, Yu. G.; Onuchak, L. A.; Evdokimova, M. A.

    2016-08-01

    The thermodynamic characteristics of sorption of 24 organic compounds of various classes from the gas phase on the binary stationary phase based on polyethylene glycol 400 and permethylated β-cyclodextrin were determined. The influence of geometrical structure and optical activity of organic compounds on the possibility of forming sorbate-macrocycle complexes was examined. It was found that the studied stationary phase shows the enantioselectivity towards low-polar terpenes under the conditions of gas chromatography.

  17. Influence of freeze-drying and γ-irradiation in preclinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using d-(+)-trehalose and polyethylene glycol.

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; García López, María Luisa; Espina García, Marta; Parra Coca, Alexander; Calpena Campmany, Ana Cristina

    2016-01-01

    This study investigated the suspension of poly(ε-caprolactone) nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs) in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5%) and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350) and d-(+)-trehalose (TRE). Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen's egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG) have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE). IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over >30 days. This study concludes that both formulations meet the Goldman's criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics, could be used as a feasible alternative to a flurbiprofen solution for ocular application in clinical trials.

  18. Disintegration and cancer immunotherapy efficacy of a squalane-in-water delivery system emulsified by bioresorbable poly(ethylene glycol)-block-polylactide.

    Science.gov (United States)

    Chen, Wei-Lin; Liu, Shih-Jen; Leng, Chih-Hsiang; Chen, Hsin-Wei; Chong, Pele; Huang, Ming-Hsi

    2014-02-01

    Vaccine adjuvant is conferred on the substance that helps to enhance antigen-specific immune response. Here we investigated the disintegration characteristics and immunotherapy potency of an emulsified delivery system comprising bioresorbable polymer poly(ethylene glycol)-polylactide (PEG-PLA), phosphate buffer saline (PBS), and metabolizable oil squalane. PEG-PLA-stabilized oil-in-water emulsions show good stability at 4 °C and at room temperature. At 37 °C, squalane/PEG-PLA/PBS emulsion with oil/aqueous weight ratio of 7/3 (denominated PELA73) was stable for 6 weeks without phase separation. As PEG-PLA being degraded, 30% of free oil at the surface layer and 10% of water at the bottom disassociated from the PELA73 emulsion were found after 3 months. A MALDI-TOF MS study directly on the DIOS plate enables us to identify low molecular weight components released during degradation. Our results confirm the loss of PLA moiety of the emulsifier PEG-PLA directly affected the stability of PEG-PLA-stabilized emulsion, leading to emulsion disintegration and squalane/water phase separation. As adjuvant for cancer immunotherapeutic use, an HPV16 E7 peptide antigen formulated with PELA73 plus immunostimulatory CpG molecules could strongly enhance antigen-specific T-cell responses as well as anti-tumor ability with respected to non-formulated or Alum-formulated peptide. Accordingly, these advances may be a potential immunoregulatory strategy in manipulating the immune responses induced by tumor-associated antigens.

  19. Influence of freeze-drying and γ-irradiation in preclinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using d-(+)-trehalose and polyethylene glycol

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; García López, María Luisa; Espina García, Marta; Parra Coca, Alexander; Calpena Campmany, Ana Cristina

    2016-01-01

    This study investigated the suspension of poly(ε-caprolactone) nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs) in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5%) and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350) and d-(+)-trehalose (TRE). Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen’s egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG) have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE). IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over >30 days. This study concludes that both formulations meet the Goldman’s criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics, could be used as a feasible alternative to a flurbiprofen solution for ocular application in clinical trials. PMID:27601897

  20. In vivo residence duration of human growth hormone loaded in nanogels comprising cinnamoyl alginate, cinnamoyl Pluronic F127 and cinnamoyl poly(ethylene glycol).

    Science.gov (United States)

    Yoon, Dong Youl; Kim, Jin-Chul

    2016-07-25

    Cinnamoyl alginate, cinnamoyl Pluronic F127 and cinnamoyl poly(ethylene glycol) were self-assembled into nanogel in aqueous phase. The size of nanogel was 100nm-200nm on TEM photos. When 1ml of human growth hormone (hGH) solution (5mg/ml, pH3.0) was mixed with 4ml of the nanogel suspension (37.5mg/ml, pH3.0), 100% of hGH was loaded in the nanogels (corresponding to specific loading of 3.33% (w hGH/w nanogel)). In the in vivo pharmacokinetics study, the substantial blood level of hGH was maintained during the entire experiment period (two weeks) after one-time injection of hGH-loaded nanogel at 0.5mg hGH/kg body weight, and the area under curve (AUC) obtained with the one-time injection of hGH-loaded nanogel was higher than AUC obtained with daily injections of free hGH at 0.05mg hGH/kg for 7days. In the in vivo pharmacodynamics study, the blood level of insulin-like growth factor (IGF-1) increased in 2h and it was maintained during the entire experiment period (two weeks) after one-time injection of hGH-loaded nanogel at 0.5mg hGH/kg body weight. The in vivo fluorescence images of mice injected with rhodamine B isothiocyanate-labelled nanogel suspension showed fluorescence intensity up to 96h after intravenous injection, indicating that the in vivo residence time of the nanogel was greater than 96h. PMID:27242314

  1. Influence of freeze-drying and γ-irradiation in preclinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using d-(+)-trehalose and polyethylene glycol.

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; García López, María Luisa; Espina García, Marta; Parra Coca, Alexander; Calpena Campmany, Ana Cristina

    2016-01-01

    This study investigated the suspension of poly(ε-caprolactone) nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs) in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5%) and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350) and d-(+)-trehalose (TRE). Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen's egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG) have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE). IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over >30 days. This study concludes that both formulations meet the Goldman's criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics, could be used as a feasible alternative to a flurbiprofen solution for ocular application in clinical trials. PMID:27601897

  2. Stability and activity of carbon nanofiber-supported catalysts in the aqueous phase reforming of ethylene glycol

    NARCIS (Netherlands)

    Haasterecht, van T.; Ludding, C.C.I.; Jong, de K.P.; Bitter, J.H.

    2013-01-01

    Nickel, cobalt, copper and platinum nanoparticles supported on carbon nano-fibers were evaluated with respect to their stability, catalytic activity and selectivity in the aqueous phase reforming of ethylene glycol (230 ¿, autogenous pressure, batch reactor). The initial surface-specific activities

  3. Stability and activity of carbon nanofiber-supported catalysts in the aqueous phase reforming of ethylene glycol

    NARCIS (Netherlands)

    van Haasterecht, T.; Ludding, C.C.I.; de Jong, K.P.; Bitter, J.H.

    2013-01-01

    Nickel, cobalt, copper and platinum nanoparticles supported on carbon nano-fibers were evaluated with respect to their stability, catalytic activity and selectivity in the aqueous phase reforming of ethylene glycol (230 ◦C, autogenous pressure, batch reactor). The initial surface-specific activities

  4. Preparation of FeO(OH Modified with Polyethylene Glycol and Its Catalytic Activity on the Reduction of Nitrobenzene with Hydrazine Hydrate

    Directory of Open Access Journals (Sweden)

    Ke Ying Cai

    2016-10-01

    Full Text Available Iron oxyhydroxide was prepared by dropping ammonia water to Fe(NO33.9H2O dispersed in polyethylene glycol (PEG 1000. The catalyst was characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and laser particle size analyzer. The results showed the catalyst modified with polyethylene glycol was amorphous. The addition of PEG during the preparation make the particle size of the catalyst was smaller and more uniform. The catalytic performance was tested in the reduction of nitroarenes to corresponding amines with hydrazine hydrate, and the catalyst showed excellent activity and stability. Copyright © 2016 BCREC GROUP. All rights reserved Received: 2nd February 2016; Revised: 26th April 2016; Accepted: 7th June 2016 How to Cite: Cai, K.Y., Liu, Y.S., Song, M., Zhou, Y.M., Liu, Q., Wang, X.H. (2016. Preparation of FeO(OH Modified with Polyethylene Glycol and Its Catalytic Activity on the Reduction of Nitrobenzene with Hydrazine Hydrate. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3: 363-368 (doi:10.9767/bcrec.11.3.576.363-368 Permalink/DOI: http://doi.org/10.9767/bcrec.11.3.576.363-368

  5. Thermal contraction of aqueous glycerol and ethylene glycol solutions for optimized protein-crystal cryoprotection.

    Science.gov (United States)

    Shen, Chen; Julius, Ethan F; Tyree, Timothy J; Moreau, David W; Atakisi, Hakan; Thorne, Robert E

    2016-06-01

    The thermal contraction of aqueous cryoprotectant solutions on cooling to cryogenic temperatures is of practical importance in protein cryocrystallography and in biological cryopreservation. In the former case, differential contraction on cooling of protein molecules and their lattice relative to that of the internal and surrounding solvent may lead to crystal damage and the degradation of crystal diffraction properties. Here, the amorphous phase densities of aqueous solutions of glycerol and ethylene glycol at T = 77 K have been determined. Densities with accuracies of cooling drops with volumes as small as 70 pl, assessing their optical clarity and measuring their buoyancy in liquid nitrogen-argon solutions. The use of these densities in contraction matching of internal solvent to the available solvent spaces is complicated by several factors, most notably the exclusion of cryoprotectants from protein hydration shells and the expected deviation of the contraction behavior of hydration water from bulk water. The present methods and results will assist in developing rational approaches to cryoprotection and an understanding of solvent behavior in protein crystals. PMID:27303794

  6. New formulation of chemical peeling agent: 30% salicylic acid in polyethylene glycol. Absorption and distribution of 14C-salicylic acid in polyethylene glycol applied topically to skin of hairless mice.

    Science.gov (United States)

    Ueda, Setsuko; Mitsugi, Koichi; Ichige, Kazumi; Yoshida, Kenji; Sakuma, Tomoko; Ninomiya, Shin-ichi; Sudou, Tetsuji

    2002-04-01

    Salicylic acid is used in chemical peeling procedures. However, they have caused many side effects, even salicylism. To achieve a salicylic acid peeling that would be safer for topical use, we recently developed a new formulation consisting of 30% salicylic acid in polyethylene glycol (PEG) vehicle. In an extension of our previous research, we studied the absorption of 30% salicylic acid labeled with 14C in PEG vehicle applied topically to the intact and damaged skin of male hairless mice. An ointment containing 3 mg salicylic acid in 10 mg vehicle was applied to both groups. In animals with intact skin, 1 h after application the plasma concentration of radioactivity was 1665.1 ng eq/ml, significantly lower than the 21437.6 ng eq/ml observed in mice with damaged skin. Microautoradiograms of intact skin showed that the level of radioactivity in the cornified cell layer was similar at 6 h after application. However, in damaged skin, the overall level of radioactivity showed a decrease by 3 h after application. In the carcasses remaining after the treated intact and damaged skin had been removed, 0.09 and 11.38% of the applied radioactivity remained, respectively. These findings confirm that 30% salicylic acid in PEG vehicle is little absorbed through the intact skin of hairless mice, and suggest that salicylism related to absorption through the skin of quantities of topically applied salicylic acid is not likely to occur in humans with intact skin during chemical peeling with this preparation. This new preparation of 30% salicylic acid in PEG vehicle is believed to be safe for application as a chemical peeling agent.

  7. The influence of tannin, pectin and polyethylene glycol on attachment of {sup 15}N-labelled rumen microorganisms to cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Bento, M.H.L. [Avian Science Research Centre, Animal Health Group, SAC, Edinburgh, Scotland (United Kingdom) and FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna (Austria)]. E-mail: helena.bento@sac.ac.uk; Acamovic, T. [Avian Science Research Centre, Animal Health Group, SAC, Edinburgh, Scotland (United Kingdom); Makkar, H.P.S. [FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna (Austria)

    2005-08-19

    The microbial attachment to and gas production from {alpha}-cellulose (Sigma; C-8002) without and with mimosa tannin (MT), pectin (P), polyethylene glycol (PEG), MT + P or MT + PEG, were investigated using the in vitro gas production system. Microbial attachment based on {sup 15}N-labelled rumen microorganisms in the residual pellet after 24 h incubation was estimated, which varied from 113.7 to 161.3 {mu}g {sup 15}N per g residual pellet. C + MT had the lowest microbial attachment (P < 0.05) of all treatments and C + P the highest (P < 0.05). Both pectin and PEG improved microbial attachment when added to C + MT (P < 0.001). Gas production was measured at 2, 4, 6, and 24 h. Mimosa tannin drastically reduced gas production only at 24 h (P < 0.001). Pectin increased gas production throughout the incubation period (P < 0.001). Both pectin and PEG increased gas production at 24 h, when added to C + MT (P < 0.05), however, for C + MT + P, the gas production was only half (P < 0.05) of the gas produced in the control (when only C incubated). A rapid degradation of pectin early in the incubation could have reduced the interaction of pectin with the MT. Microbial attachment agreed well with gas production at 24 h (R{sup 2} = 0.84, P < 0.001). However, the inclusion of MT and pectin may have resulted in differences in microbial profiles, thereby altering the capability of the adhered microbes to degrade cellulose. This assertion is supported by the lower gas production (ml per {mu}g of {sup 15}N) in the residual pellet measured for C + MT (0.054) and C + MT + P (0.159), compared with the other treatments (0.32 for C; 0.34 for C + P; 0.33 for C + PEG; and 0.33 for C + MT + PEG). A MT concentration of 194 g/kg diet reduced microbial attachment and activity of rumen microorganisms in vitro. Polyethylene glycol counteracted the effect of MT on microbial attachment and activity. Pectin exerted a beneficial effect on attachment and fermentation in the initial hours of incubation

  8. The effect of polyethylene glycol spacer chain length on the tumor-targeting potential of folate-modified PPI dendrimers

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Shrikant [Dr. Hari Singh Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India); Tekade, Rakesh K., E-mail: rakeshtekade@yahoo.com [University of Hawai' i at Hilo, College of Pharmacy (United States); Kesharwani, Prashant, E-mail: prashant_pharmacy04@rediffmail.com; Jain, Narendra K., E-mail: jnarendr@yahoo.co.in [Dr. Hari Singh Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India)

    2013-05-15

    The objective of the present investigation was to assess the tumor-targeting potential of ligand-spacer-engineered poly (propylene imine) (PPI) dendrimers as nanoscale drug delivery units for site-specific delivery of a model anticancer agent, docetaxel (DTX). PPI dendrimers were engineered by direct and indirect conjugation of folic acid (FA) via different types of polyethylene glycols (PEGs) [Mw (molecular weight): 1,000, 4,000, 6,000, 7,500] as spacers. The synthesized nanoconjugates (PPIFA, PPIP1FA, PPIP4FA, PPIP6FA, and PPIP7.5FA) were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance ({sup 1}H-NMR) and transmission electron microscopic (TEM) studies. Nanoconjugates were evaluated for entrapment, in vitro drug release (under various pH conditions) and hemolytic studies. Cell uptake and cytotoxicity studies were performed on human malignant cell lines (MCF-7) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide [MTT] assay. This debut study explored the effect of PEG spacer length on the targeting potential of folate-conjugated 5.0 G PPI dendrimer. DTX entrapment and in vitro drug release from nanoconjugates augmented, and hemolytic toxicity of nanoconjugates slashed with the molecular weight of PEGs. Further, nanoconjugates with PEG 4000 displayed highest tumor-targeting potential as compared to other spacer conjugated nanoconjugates due to optimized steric hindrance and receptor mediated endocytosis among other PEGs. This work is expected to shed new light on the role of spacer chain length in targeting potential of folate-anchored dendrimer.Graphical Abstract.

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

    Science.gov (United States)

    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

  10. Polyethylene Glycol-Based Synthetic Hydrogel Sealant for Closing Vitrectomy Wounds: An In Vivo and Histological Study

    Science.gov (United States)

    Hoshi, Sujin; Okamoto, Fumiki; Arai, Mikki; Hirose, Tatsuo; Fukuda, Shinichi; Sugiura, Yoshimi; Oshika, Tetsuro

    2016-01-01

    Purpose We conducted an in vivo study using Dutch pigmented rabbit eyes to test the usefulness of polyethylene glycol (PEG) sealant for the closure of sutureless sclerotomies in microincisional vitrectomy surgery (MIVS). Methods Three-port, 23-gauge vitrectomy was performed on rabbit eyes. After air leakage was confirmed by the application of 0.625% povidone–iodine at the sclerotomy site, PEG sealant was subconjunctivally injected using a 27-gauge needle through conjunctival incisions to cover the sclerotomy wounds, following which it was polymerized by the application of xenon light for 60 seconds. Ophthalmological examinations and intraocular pressure measurements were conducted the day before and 1, 3, 5, and 7 days after surgery. The eyes were enucleated for histological evaluation 7 days after surgery. Results PEG sealant was rapidly polymerized by the application of xenon light after subconjunctival injection, and it firmly sealed the sclerotomies without air leakage, as confirmed by povidone–iodine dropping, in all cases. Conjunctival and scleral wounds closed with PEG sealant were successfully attached and remained intact till the end of the follow-up period. There was no sign of postoperative hypotony or infection in any eye, and no adverse effects of PEG sealant were found. In histological examination, linear scar formation and eosinophilic staining of collagen fibers were observed at the sclerotomy sites, while the sclerotomy tunnels appeared tightly closed. Conclusions PEG sealant can be useful for the closure of sutureless 23-gauge vitrectomy incisions in rabbits. Translational Relevance The PEG sealant may become an effective option for closing vitrectomy incisions including pediatric cases. PMID:27226931

  11. Topical polyethylene glycol as a novel chemopreventive agent for oral cancer via targeting of epidermal growth factor response.

    Directory of Open Access Journals (Sweden)

    Ramesh K Wali

    Full Text Available Head and neck squamous cell carcinoma (HNSCC is a major cause of morbidity and mortality underscoring the need for safe and effective chemopreventive strategies. Targeting epidermal growth factor receptor (EGFR is attractive in that it is an early critical event in HNSCC pathogenesis. However, current agents lack efficacy or have unacceptable toxicity. Several groups have demonstrated that the over-the-counter medication, polyethylene glycol (PEG has remarkable chemopreventive efficacy against colon carcinogenesis. Importantly, we reported that this effect is mediated through EGFR internalization/degradation. In the current study, we investigated the chemopreventive efficacy of this agent against HNSCC, using both the well validated animal model 4-NQO (4-nitroquinoline 1-oxide rat model and cell culture with the human HNSCC cell line SCC-25. We demonstrated that daily topical application of 10% PEG-8000 in the oral cavity (tongue and cavity wall post 4NQO initiation resulted in a significant reduction in tumor burden (both, tumor size and tumors/tumor bearing rat without any evidence of toxicity. Immunohistochemical studies depicted decreased proliferation (number of Ki67-positive cells and reduced expression of EGFR and its downstream effectors cyclin D1 in the tongue mucosa of 4NQO-rats treated with PEG. We showed that EGFR was also markedly downregulated in SCC-25 cells by PEG-8000 with a concomitant induction of G1-S phase cell-cycle arrest, which was potentially mediated through upregulated p21(cip1/waf1. In conclusion, we demonstrate, for the first time, that PEG has promising efficacy and safety as a chemopreventive efficacy against oral carcinogenesis.

  12. Polyethylene-glycol-doped polypyrrole increases the rate performance of the cathode in lithium-sulfur batteries.

    Science.gov (United States)

    Wu, Feng; Chen, Junzheng; Li, Li; Zhao, Teng; Liu, Zhen; Chen, Renjie

    2013-08-01

    Polypyrrole-polyethylene glycol (PPy/PEG)-modified sulfur/aligned carbon nanotubes (PPy/PEG-S/A-CNTs) were synthesized by using an in situ polymerization method. The ratio of PPy to PEG equaled 31.7:1 after polymerization, and the PEG served as a cation dopant in the polymerization and electrochemical reactions. Elemental analysis, FTIR, Raman spectroscopy, XRD, and electrochemical methods were performed to measure the physicochemical properties of the composite. Elemental analysis demonstrated that the sulfur, PPy, PEG, A-CNT, and chloride content in the synthesized material was 64.6%, 22.1%, 0.7%, 12.1%, and 0.5%, respectively. The thickness of the polymer shell was about 15-25 nm, and FTIR confirmed the successful PPy/PEG synthesis. The cathode exhibited a high initial specific capacity of 1355 mAh g(-1) , and a sulfur usage of 81.1%. The reversible capacity of 924 mAh g(-1) was obtained after 100 cycles, showing a remarkably improved cyclability compared to equivalent systems without PEG doping and without any coatings. PPy/PEG provided an effective electronically conductive network and a stable interface structure for the cathode. Rate performance of the PPy/PEG- S/A-CNT composite was more than double that of the unmodified S/A-CNTs. Remarkably, the battery could work at a very high current density of 8 A g(-1) and reached an initial capacity of 542 mAh g(-1) ; it also retained a capacity of 480 mAh g(-1) after 100 cycles. The addition of PEG as a dopant in the PPy shell contributed to this prominent rate improvement. Lithium ions and electrons were available everywhere on the surfaces of the particles, and thus could greatly improve the electrochemical reaction; PEG is a well-known solvent for lithium salts and a very good lithium-ion catcher. PMID:23788469

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

    Directory of Open Access Journals (Sweden)

    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.

  14. A better anti-diabetic recombinant human fibroblast growth factor 21 (rhFGF21 modified with polyethylene glycol.

    Directory of Open Access Journals (Sweden)

    Zhifeng Huang

    Full Text Available As one of fibroblast growth factor (FGF family members, FGF21 has been extensively investigated for its potential as a drug candidate to combat metabolic diseases. In the present study, recombinant human FGF21 (rhFGF21 was modified with polyethylene glycol (PEGylation in order to increase its in vivo biostabilities and therapeutic potency. At N-terminal residue rhFGF21 was site-selectively PEGylated with mPEG20 kDa-butyraldehyde. The PEGylated rhFGF21 was purified to near homogeneity by Q Sepharose anion-exchange chromatography. The general structural and biochemical features as well as anti-diabetic effects of PEGylated rhFGF21 in a type 2 diabetic rat model were evaluated. By N-terminal sequencing and MALDI-TOF mass spectrometry, we confirmed that PEG molecule was conjugated only to the N-terminus of rhFGF21. The mono-PEGylated rhFGF21 retained the secondary structure, consistent with the native rhFGF21, but its biostabilities, including the resistance to physiological temperature and trypsinization, were significantly enhanced. The in vivo immunogenicity of PEGylated rhFGF21 was significantly decreased, and in vivo half-life time was significantly elongated. Compared to the native form, the PEGylated rhFGF21 had a similar capacity of stimulating glucose uptake in 3T3-L1 cells in vitro, but afforded a significantly long effect on reducing blood glucose and triglyceride levels in the type 2 diabetic animals. These results suggest that the PEGylated rhFGF21 is a better and more effective anti-diabetic drug candidate than the native rhFGF21 currently available. Therefore, the PEGylated rhFGF21 may be potentially applied in clinics to improve the metabolic syndrome for type 2 diabetic patients.

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

    Science.gov (United States)

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

    2014-11-28

    Women with bacterial vaginosis (BV) display reduced vaginal acidity, which make them susceptible to associated infections such as HIV. In the current study, poly(ethylene glycol) (PEG) nanocarrier-based degradable hydrogels were developed for the controlled release of lactic acid in the vagina of BV-infected women. PEG-lactic acid (PEG-LA) nanocarriers were prepared by covalently attaching lactic acid to 8-arm PEG-SH via cleavable thioester bonds. PEG-LA nanocarriers with 4 copies of lactic acid per molecule provided controlled release of lactic acid with a maximum release of 23% and 47% bound lactic acid in phosphate buffered saline (PBS, pH7.4) and acetate buffer (AB, pH4.3), respectively. The PEG nanocarrier-based hydrogels were formed by cross-linking the PEG-LA nanocarriers with 4-arm PEG-NHS via degradable thioester bonds. The nanocarrier-based hydrogels formed within 20 min under ambient conditions and exhibited an elastic modulus that was 100-fold higher than the viscous modulus. The nanocarrier-based degradable hydrogels provided controlled release of lactic acid for several hours; however, a maximum release of only 10%-14% bound lactic acid was observed possibly due to steric hindrance of the polymer chains in the cross-linked hydrogel. In contrast, hydrogels with passively entrapped lactic acid showed burst release with complete release within 30 min. Lactic acid showed antimicrobial activity against the primary BV pathogen Gardnerella vaginalis with a minimum inhibitory concentration (MIC) of 3.6 mg/ml. In addition, the hydrogels with passively entrapped lactic acid showed retained antimicrobial activity with complete inhibition G. vaginalis growth within 48 h. The results of the current study collectively demonstrate the potential of PEG nanocarrier-based hydrogels for vaginal administration of lactic acid for preventing and treating BV.

  16. Seed Germination Behaviors Of Some Aerobic Rice Cultivars Oryza Sativa L After Priming With Polyethylene Glycol-8000 Peg-8000

    Directory of Open Access Journals (Sweden)

    Elkheir H.A

    2015-08-01

    Full Text Available Seed Priming Is Famous Technique To Accelerate Seed Germination Behaviors. This Experiment Was Conducted To Study The Effect Of Polyethylene Glycol-8000 Peg-8000 As Priming Agent On Seed Germination Behavior Of Some Aerobic Rice Cultivars Oryza Sativa L. Experiment Was Carried Out By Using Two-Factor Three Aerobic Rice Cultivars And Peg With Four Replications Which Arranged In Factorial System Design And Conducted With Completely Randomized Design. The Factor Was Varieties Which Were Inpago 8 V1 Ir64 V2 And Situbagendit V3 Combine With 4 Levels Of Peg Concentrations 0100 And 200 Gl-1 And Control With No Treatment. Experiment Was Repeated 4 Times So Total Number Of Experimental Units Were 48. Germination Parameters Measured Were Germination Percentage Germination Index Days Of 50 Germination Seedling Fresh Weight Mg Seedling Shoot Fresh Weight And Root Fresh Weight Mg Seedling Dry Weigh Mg Seedling Shoot Dry Weight And Root Dry Weight Mg ShootRoot Ratio Seedling Length Cm Seedling Root Length Cm And Shoot Length Cm And Seed Vigor Index. The Results Indicated That Seed Priming Significantly Affected Germination Behaviors Compared With Control Depending Upon Varieties. The Highest Germination Was Obtained Under Laboratory And Greenhouse Condition By The Treatment Of Peg 200 G L-1 On The Situbagendit And Ir-64 Variety 90.25 And 93.33 Respectively Compared To Control In Inpago-8 In Both Laboratory 75.75 And Greenhouse 80 . As Implementation To Increase Seed And Seedling Vigor Of Rice It Is A Best Practice To Use Peg Priming With 200 Gl-1 Solutions Depend Upon Varietal Response And We Suggest That More Research About The Effect Of Peg As Seed Priming Techniques On Seed Germination Behavior Of Many Grain Crops Is Needed To Confirm The Methodology.

  17. A population-based case-crossover study of polyethylene glycol use and acute renal failure risk in the elderly

    Institute of Scientific and Technical Information of China (English)

    Nam-Kyong Choi; Yoosoo Chang; Sun-Young Jung; Yu-Kyong Choi; Joongyub Lee; Jin-Ho Lee; Ju-Young Kim; Byung-Joo Park

    2011-01-01

    AIM: To evaluate the possibility of an association between polyethylene glycol (PEG) and acute renal failure (ARF) in elderly patients using a health insurance claims database.METHODS: We conducted a population-based casecrossover study using information obtained from Korean Health Insurance Review and Assessment Service (HIRA)claims from January 1, 2005 to December 31, 2005(Seoul, Korea). The study population consisted of elderly patients who received PEG prior to experiencing their first ARF-related hospitalization from April 1, 2005 to December 31, 2005. For each patient, one case and two control periods were matched. PEG use in a 2- or 4-wk window period prior to hospitalization for ARF was compared with PEG use in two earlier 2- or 4-wk control window periods. Conditional logistic regression analysis was used to estimate odds ratios (ORs) and 95% CI, adjusting for concomitant uses of diuretics, angiotensin converting enzyme inhibitors, non-steroidal anti-inflammatory drugs,antibiotics, anti-cancer drugs, and contrast media.RESULTS: Within the HIRA database which contained 1 093 262 elderly patients, 1156 hospitalized ARF cases were identified. Among these cases, PEG was prescribed to 17 (1.5%) patients before hospitalization. The adjusted ORs when applying the 2- and 4-wk window periods were 0.4 (95% CI: 0.03-5.24) and 2.1 (95% CI:0.16-27.78), respectively.CONCLUSION: No increased risk of ARF was found in elderly PEG users. However, based on the limited number of study subjects, further analysis should be performed to confirm these results.

  18. Sensitive colorimetric visualization of perfluorinated compounds using poly(ethylene glycol) and perfluorinated thiols modified gold nanoparticles.

    Science.gov (United States)

    Niu, Hongyun; Wang, Saihua; Zhou, Zhen; Ma, Yurong; Ma, Xunfeng; Cai, Yaqi

    2014-05-01

    In this work, we have developed a novel sensing strategy employing mixed poly(ethylene glycol)-terminated (PEG-thiols) and perfluoroalkyl-terminated (F-thiols) alkanethiols modified gold nanoparticles (Au@PEG-F NPs) as a probe to detect perfluorinated compounds (PFCs) from water samples. PEG-thiols with high density and long carbon chains make the Au NPs probe well-dispersed in solution and stable even in high concentration of salt solution; F-thiols provide specific fluorous-fluorous interactions to PFCs, which results in adsorption of PFCs on Au@PEG-F NPs. The adsorbed PFCs cause the aggregation of Au@PEG-F NPs probes and thus induce the insolubility of probes and precipitation directly from reaction solution due to the superhydrophobicity of perfluorocarbon monolayers, leading to color and absorbance response of the assay to PFCs. The preparation of the Au@PEG-F NPs probe is very simple, and the colorimetric assay based on this mechanism for the detection of PFCs is selective and convenient. Combined with UV-vis spectrophotometry, the assay demonstrates good sensitivities to PFCs with wide linear range. In the designed concentration range, the response of the colorimetric assay to long-chain PFCs (perfluoroalkyl chain ≥7) is discerned even as the concentration of these PFCs is as low as 10 μg L(-1). This low-cost and sensitive assay shows great potential to measure total PFCs in water samples. To the best of our knowledge, this is the first application of the specific fluorous-fluorous interactions and Au NPs based probes for colorimetric recognition for PFCs. PMID:24684731

  19. Improving biocompatibility by controlling protein adsorption: Modification and design of biomaterials using poly(ethylene glycol) microgels and microspheres

    Science.gov (United States)

    Scott, Evan Alexander

    2009-12-01

    Guided by the clinical needs of patients and developments in biology and materials science, the primary focus of the biomaterials field remains at the solid/liquid interface between biomaterial surfaces and biological fluids. For blood-contacting devices, biological responses are initially elicited and directed by proteins that adsorb from this multicomponent solution to form thin films on their surfaces. The identity, conformation, and quantity of adsorbed proteins are related to the properties of a material's surface. For example, hydrophobic surfaces tend to be thrombotic via interactions between platelets and adsorbed fibrinogen, while surface-activation of specific enzymes initiates the coagulation cascade on hydrophilic surfaces. The objective of this thesis is to improve the design of biomaterials through the analysis and control of adsorbing protein layers. This goal is approached through three separate strategies. First, a proteomics-based methodology is presented for the assessment of protein conformation at the residue level after adsorption to biomaterial surfaces. A quantitative mass spectrometric technique is additionally suggested for the identification and quantification of proteins within adsorbed protein layers. Second, a method is described for the covalent attachment of poly(ethylene glycol) (PEG)-based hydrogel coatings onto biomaterials surfaces for the minimization of protein adsorption. The coatings are applied using partially crosslinked PEG solutions containing polymer and protein oligomers and microgels that can be designed to control cell adhesion. Finally, a modular strategy is proposed for the assembly of bioactive PEG-based hydrogel scaffolds. This was accomplished using novel PEG microspheres with diverse characteristics that individually contribute to the ability of the scaffold to direct cellular infiltration. The methodologies proposed by this thesis contribute to the recent shift in biomaterials and tissue engineering strategies

  20. Determination of the surface density of polyethylene glycol on gold nanoparticles by use of microscale thermogravimetric analysis.

    Science.gov (United States)

    Sebby, K B; Mansfield, E

    2015-04-01

    The widespread integration of nanoparticle technologies into biomedicine will depend on the ability to repeatedly create particles with well-defined properties and predictable behaviors. For this to happen, fast, reliable, inexpensive, and widely available techniques to characterize nanomaterials are needed. Characterization of the surface molecules is particularly important since the surface, including the surface molecule density, plays a dominant role in determining how nanoparticles interact with their surroundings. Here, 10 and 30 nm gold nanoparticle NIST Standard Reference Materials were functionalized with fluorescently labeled polyethylene glycol (PEG) with either thiolate or lipoic acid anchoring groups to evaluate analytical techniques for determining surface coverage. The coating of the nanoparticles was confirmed with dynamic light scattering, microscale thermogravimetric analysis (μ-TGA), and ultraviolet-visible (UV-vis) spectroscopy. A UV-vis method for determining gold nanoparticle concentrations that takes into account spectral broadening upon functionalization was developed. The amount of bound PEG was quantified with μ-TGA, a technique analogous to thermogravimetric analysis that uses quartz crystal microbalances, and fluorescence spectroscopy of displaced ligands. It is shown that μ-TGA is a convenient technique for the quantification of ligands bound to inorganic particles while sacrificing a minimal amount of sample, and the treatment of the functionalized nanoparticle dispersions with dithiothreitol may be insufficient to achieve complete displacement of the surface ligands for quantification by fluorescence measurements. The μ-TGA and fluorescence results were used to determine ligand footprint sizes-average areas occupied by each ligand on the particles' surface. The lipoic acid bound ligands had footprint sizes of 0.21 and 0.25 nm(2) on 10 and 30 nm particles, respectively while the thiolate ligands had footprint sizes of 0.085 and 0

  1. Tuning mechanical performance of poly(ethylene glycol) and agarose interpenetrating network hydrogels for cartilage tissue engineering.

    Science.gov (United States)

    Rennerfeldt, Deena A; Renth, Amanda N; Talata, Zsolt; Gehrke, Stevin H; Detamore, Michael S

    2013-11-01

    Hydrogels are attractive for tissue engineering applications due to their incredible versatility, but they can be limited in cartilage tissue engineering applications due to inadequate mechanical performance. In an effort to address this limitation, our team previously reported the drastic improvement in the mechanical performance of interpenetrating networks (IPNs) of poly(ethylene glycol) diacrylate (PEG-DA) and agarose relative to pure PEG-DA and agarose networks. The goal of the current study was specifically to determine the relative importance of PEG-DA concentration, agarose concentration, and PEG-DA molecular weight in controlling mechanical performance, swelling characteristics, and network parameters. IPNs consistently had compressive and shear moduli greater than the additive sum of either single network when compared to pure PEG-DA gels with a similar PEG-DA content. IPNs withstood a maximum stress of up to 4.0 MPa in unconfined compression, with increased PEG-DA molecular weight being the greatest contributing factor to improved failure properties. However, aside from failure properties, PEG-DA concentration was the most influential factor for the large majority of properties. Increasing the agarose and PEG-DA concentrations as well as the PEG-DA molecular weight of agarose/PEG-DA IPNs and pure PEG-DA gels improved moduli and maximum stresses by as much as an order of magnitude or greater compared to pure PEG-DA gels in our previous studies. Although the viability of encapsulated chondrocytes was not significantly affected by IPN formulation, glycosaminoglycan (GAG) content was significantly influenced, with a 12-fold increase over a three-week period in gels with a lower PEG-DA concentration. These results suggest that mechanical performance of IPNs may be tuned with partial but not complete independence from biological performance of encapsulated cells.

  2. Targeted drug delivery nanosystems based on copolymer poly(lactide)-tocopheryl polyethylene glycol succinate for cancer treatment

    Science.gov (United States)

    Thu Ha, Phuong; Nguyen, Hoai Nam; Doan Do, Hai; Thong Phan, Quoc; Nguyet Tran Thi, Minh; Phuc Nguyen, Xuan; Nhung Hoang Thi, My; Huong Le, Mai; Nguyen, Linh Toan; Quang Bui, Thuc; Hieu Phan, Van

    2016-03-01

    Along with the development of nanotechnology, drug delivery nanosystems (DDNSs) have attracted a great deal of concern among scientists over the world, especially in cancer treatment. DDNSs not only improve water solubility of anticancer drugs but also increase therapeutic efficacy and minimize the side effects of treatment methods through targeting mechanisms including passive and active targeting. Passive targeting is based on the nano-size of drug delivery systems while active targeting is based on the specific bindings between targeting ligands attached on the drug delivery systems and the unique receptors on the cancer cell surface. In this article we present some of our results in the synthesis and testing of DDNSs prepared from copolymer poly(lactide)-tocopheryl polyethylene glycol succinate (PLA-TPGS), which carry anticancer drugs including curcumin, paclitaxel and doxorubicin. In order to increase the targeting effect to cancer cells, active targeting ligand folate was attached to the DDNSs. The results showed copolymer PLA-TPGS to be an excellent carrier for loading hydrophobic drugs (curcumin and paclitaxel). The fabricated DDNSs had a very small size (50-100 nm) and enhanced the cellular uptake and cytotoxicity of drugs. Most notably, folate-decorated paclitaxel-loaded copolymer PLA-TPGS nanoparticles (Fol/PTX/PLA-TPGS NPs) were tested on tumor-bearing nude mice. During the treatment time, Fol/PTX/PLA-TPGS NPs always exhibited the best tumor growth inhibition compared to free paclitaxel and paclitaxel-loaded copolymer PLA-TPGS nanoparticles. All results evidenced the promising potential of copolymer PLA-TPGS in fabricating targeted DDNSs for cancer treatment.

  3. [Improvement of sensitivity in the second generation HCV core antigen assay by a novel concentration method using polyethylene glycol (PEG)].

    Science.gov (United States)

    Higashimoto, Makiko; Takahashi, Masahiko; Jokyu, Ritsuko; Syundou, Hiromi; Saito, Hidetsugu

    2007-11-01

    A HCV core antigen (Ag) detection assay system, Lumipulse Ortho HCV Ag has been developed and is commercially available in Japan with a lower detection level limit of 50 fmol/l, which is equivalent to 20 KIU/ml in PCR quantitative assay. HCV core Ag assay has an advantage of broader dynamic range compared with PCR assay, however the sensitivity is lower than PCR. We developed a novel HCV core Ag concentration method using polyethylene glycol (PEG), which can improve the sensitivity five times better than the original assay. The reproducibility was examined by consecutive five-time measurement of HCV patients serum, in which the results of HCV core Ag original and concentrated method were 56.8 +/- 8.1 fmol/l (mean +/- SD), CV 14.2% and 322.9 +/- 45.5 fmol/l CV 14.0%, respectively. The assay results of HCV negative samples in original HCV core Ag were all 0.1 fmol/l and the results were same even in the concentration method. The results of concentration method were 5.7 times higher than original assay, which was almost equal to theoretical rate as expected. The assay results of serially diluted samples were also as same as expected data in both original and concentration assay. We confirmed that the sensitivity of HCV core Ag concentration method had almost as same sensitivity as PCR high range assay in the competitive assay study using the serially monitored samples of five HCV patients during interferon therapy. A novel concentration method using PEG in HCV core Ag assay system seems to be useful for assessing and monitoring interferon treatment for HCV.

  4. Silica–polyethylene glycol hybrids synthesized by sol–gel: Biocompatibility improvement of titanium implants by coating

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 21, 81031 Aversa (Italy); Bollino, F.; Papale, F. [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 21, 81031 Aversa (Italy); Ferrara, C.; Mustarelli, P. [Department of Chemistry, University of Pavia and INSTM, Via Taramelli 12, 27100 Pavia (Italy)

    2015-10-01

    Although metallic implants are the most used in dental and orthopaedic fields, they can early fail due to low tissue tolerance or osseointegration ability. To overcome this drawback, functional coatings can be applied on the metallic surface to provide a firm fixation of the implants. The objective of the present study was twofold: to synthesize and to characterize silica/polyethylene glycol (PEG) hybrid materials using sol–gel technique and to investigate their capability to dip-coat titanium grade 4 (Ti-gr4) substrates to improve their biological properties. Various hybrid systems have been synthesized by changing the ratio between the organic and inorganic phases in order to study the influence of the polymer amount on the structure and, thus, on the properties of the coatings. Fourier transform infrared (FTIR) spectroscopy and solid state Nuclear Magnetic Resonance (NMR) allowed us to detect the formation of hydrogen bonds between the inorganic sol–gel matrix and the organic component. SEM analysis showed that high PEG content enables to obtain crack free-coating. Moreover, the effective improvement in biological properties of Ti-gr4 implants has been evaluated by performing in vitro tests. The bioactivity of the hybrid coatings has been showed by the hydroxyapatite formation on the surface of SiO{sub 2}/PEG coated Ti-gr4 substrates after soaking in a simulated body fluid and the lack of cytotoxicity by the WST-8 Assay. The results showed that the coated substrates are more bioactive and biocompatible than the uncoated ones and that the bioactivity is not significantly affected by PEG amount whereas its addition makes the films more biocompatible. - Highlights: • SiO{sub 2}/PEG hybrid biomaterials synthesized by sol–gel method at various PEG percentages • Hybrid coating of titanium substrate with dip-coating technology • Chemical and morphological characterization of hybrids and coating • Biocompatibility improvement of coated titanium with high

  5. A comparative study of polyethylene glycol hydrogels derivatized with the RGD peptide and the cell-binding domain of fibronectin.

    Science.gov (United States)

    Zhang, Chen; Hekmatfer, Sogol; Karuri, Nancy W

    2014-01-01

    The goal of our study was to compare the biological responses of cells cultured on polyethylene glycol (PEG) hydrogels functionalized with varying concentrations of the widely used adhesion peptide, RGD, and the cell-binding domain of fibronectin, III(9-10). We used Michael addition chemistry to covalently link cysteines in GRGDSPC and glutathione S-transferase (GST) tagged III(9-10) (GST-III(9-10)), to the acrylate groups in PEG diacrylate (PEGDA). Conjugation of GST-III(9-10) to PEGDA occurred through cysteine residues in GST. Ellman's reagent and immunoblotting studies demonstrated an efficiency of 90% or more for PEG conjugation of 1 μM GST-III(9-10) or GRDGSPC in 10% (wt/vol) PEGDA at 37°C for 1 h. Circular dichroism and limited proteolysis demonstrated that conjugating PEGDA to GST-III(9-10) did not significantly perturb its native secondary structure. Sodium dodecyl sulfate polyacrylamide gel electrophoresis characterization of the wash solution of PEG hydrogels after photopolymerization demonstrated that >95% of the 1 μM GST-III(9-10) was incorporated into the PEG hydrogels after cross-linking. PEG hydrogels derivatized with 1 μM GST-III(9-10) had significantly higher cell adhesion and spreading than PEG hydrogels with 1 μM GRGDSPC. A comparable adhesion response between GRGDSPC and GST-III(9-10) was obtained when the former was at millimolar and the latter at micromolar concentration. The amount and type of conjugate in the PEG hydrogel derivative was statistically more significant than hydrogel rigidity in stimulating the biological responses observed. This report presents new evidence of the robustness of III(9-10) in mediating cell adhesion and spreading on PEG hydrogels.

  6. Clathrate hydrate equilibria in mixed monoethylene glycol and electrolyte aqueous solutions

    International Nuclear Information System (INIS)

    Highlights: ► New water activity of mixed salt(s) and MEG aqueous solutions were measured. ► New 3-phase H–Lw–V data for methane and a natural gas in equilibrium with MEG and NaCl solutions are reported. ► The CPA-EoS combined with a modified Debye Hückel electrostatic term is employed to model the phase equilibria. ► Water activity data were used to adjust parameters of the modified Debye Hückel electrostatic term. ► The modified model was independently validated using hydrate data. - Abstract: Monoethylene glycol (MEG) is commonly added in the formulation of hydraulic and drilling fluids and injected into pipelines to prevent the formation of gas hydrates. It is therefore necessary to establish the effect of a combination of salts and thermodynamic inhibitors on gas hydrate equilibria. In this communication, water activity of five ternary solutions (MEG–H2O–NaCl, MEG–H2O–CaCl2, MEG–H2O–MgCl2, MEG–H2O–KCl and MEG–H2O–NaBr) and four multicomponent solutions have been measured by a reliable resistive electrolytic humidity sensor. We also report new experimental measurements of the locus of incipient hydrate-liquid water–vapour curve for systems containing methane or natural gas with aqueous solution of ethylene glycol and NaCl over a wide range of concentrations, pressures and temperatures. A thermodynamic approach in which the Cubic-Plus-Association equation of state is combined with a modified Debye Hückel electrostatic term is employed to model the phase equilibria. These new data have been used to optimise binary interaction parameters between salts and MEG implemented in the modified Debye Hückel electrostatic term. The model developed has been evaluated using the new generated hydrate data and literature data. Good agreement between predictions of the modified model and experimental data is observed, supporting the reliability of the developed model.

  7. Precipitation of calcium carbonate in aqueous solutions in presence of ethylene glycol and dodecane.

    Science.gov (United States)

    Natsi, Panagiota D.; Rokidi, Stamatia; Koutsoukos, Petros G.

    2015-04-01

    The formation of calcium carbonate (CaCO3) in aqueous supersaturated solutions has been intensively studied over the past decades, because of its significance for a number of processes of industrial and environmental interest. In the oil and gas production industry the deposition of calcium carbonate affects adversely the productivity of the wells. Calcium carbonate scale deposits formation causes serious problems in water desalination, CO2 sequestration in subsoil wells, in geothermal systems and in heat exchangers because of the low thermal coefficient of the salt. Amelioration of the operational conditions is possible only when the mechanisms underlying nucleation and crystal growth of calcium carbonate in the aqueous fluids is clarified. Given the fact that in oil production processes water miscible and immiscible hydrocarbons are present the changes of the dielectric constant of the fluid phase has serious impact in the kinetics of calcium carbonate precipitation, which remains largely unknown. The problem becomes even more complicated if polymorphism exhibited by calcium carbonate is also taken into consideration. In the present work, the stability of aqueous solutions supersaturated with respect to all calcium carbonate polymorphs and the subsequent kinetics of calcium carbonate precipitation were measured. The measurements included aqueous solutions and solutions in the presence of water miscible (ethylene glycol, MEG) and water immiscible organics (n-dodecane). All measurements were done at conditions of sustained supersaturation using the glass/ Ag/AgCl combination electrode as a probe of the precipitation and pH as the master variable for the addition of titrant solutions with appropriate concentration needed to maintenance the solution supersaturation. Initially, the metastable zone width was determined from measurements of the effect of the solution supersaturation on the induction time preceding the onset of precipitation at free-drift conditions. The

  8. Solubility of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycols 400 or 600, propylene glycol and water at 298.2K - experimental data and modeling

    Directory of Open Access Journals (Sweden)

    Bastami Zahra

    2014-01-01

    Full Text Available Experimental molar solubilities of clonazepam and diazepam in binary and ternary mixtures of polyethylene glycols (PEGs 400 or 600, propylene glycol (PG and water (138 data points along with the density of the saturated solutions at 298.2K were reported. The Jouyban-Acree model was used to fit to the measurements for providing a computational method. Employing the solubilities in the mono-solvents, the measured solubilities in mixed solvents were back-calculated and the overall mean percentage deviations (OMPDs of the model were 16.0 % and 19.2% for diazepam and clonazepam, respectively. Addition of the Hansen solubility parameters to the model helps us to train all the data sets (clonazepam and diazepam at once and the back-calculated OMPD for this analysis was 19.3%.

  9. ROLE OF TUNGSTEN IN THE AQUEOUS PHASE HYDRODEOXYGENATION OF ETHYLENE GLYCOL ON TUNGSTATED ZIRCONIA SUPPORTED PALLADIUM

    Energy Technology Data Exchange (ETDEWEB)

    Marin-Flores, Oscar G.; Karim, Ayman M.; Wang, Yong

    2014-11-15

    The focus of the present work was specifically on the elucidation of the role played by tungsten on the catalytic activity and selectivity of tungstated zirconia supported palladium (Pd-mWZ) for the aqueous phase hydrodeoxygenation (APHDO) of ethylene glycol (EG). Zirconia supported palladium (Pd-mZ) was used as reference. The catalysts were prepared via incipient wet impregnation and characterized using X-ray diffraction (XRD), temperature-programmed reduction (TPR), CO pulse chemisorption, CO-DRIFTS, ammonia temperature-programmed desorption (NH3-TPD) and pyridine adsorption. The presence of W results in larger Pd particles on supported Pd catalysts, i.e., 0.9 and 6.1 nm Pd particles are for Pd-mZ and Pd-mWZ, respectively. For comparison purposes, the activity of the catalytic materials used in this work was obtained using a well-defined set of operating conditions. The catalytic activity measurements show that the overall intrinsic activity of Pd particles on mWZ is 1.9 times higher than on mZ. APHDO process appears to be highly favored on Pd-mWZ whereas Pd-mZ exhibits a higher selectivity for reforming. This difference in terms of selectivity seems to be related to the high concentration of Brønsted acid sites and electron-deficient Pd species present on Pd-mWZ.

  10. Vorinostat with sustained exposure and high solubility in poly(ethylene glycol)-b-poly(DL-lactic acid) micelle nanocarriers: characterization and effects on pharmacokinetics in rat serum and urine.

    Science.gov (United States)

    Mohamed, Elham A; Zhao, Yunqi; Meshali, Mahasen M; Remsberg, Connie M; Borg, Thanaa M; Foda, Abdel Monem M; Takemoto, Jody K; Sayre, Casey L; Martinez, Stephanie E; Davies, Neal M; Forrest, M Laird

    2012-10-01

    The histone deacetylase inhibitor suberoylanilide hydroxamic acid, known as vorinostat, is a promising anticancer drug with a unique mode of action; however, it is plagued by low water solubility, low permeability, and suboptimal pharmacokinetics. In this study, poly(ethylene glycol)-b-poly(DL-lactic acid) (PEG-b-PLA) micelles of vorinostat were developed. Vorinostat's pharmacokinetics in rats was investigated after intravenous (i.v.) (10 mg/kg) and oral (p.o.) (50 mg/kg) micellar administrations and compared with a conventional polyethylene glycol 400 solution and methylcellulose suspension. The micelles increased the aqueous solubility of vorinostat from 0.2 to 8.15 ± 0.60 and 10.24 ± 0.92 mg/mL at drug to nanocarrier ratios of 1:10 and 1:15, respectively. Micelles had nanoscopic mean diameters of 75.67 ± 7.57 and 87.33 ± 8.62 nm for 1:10 and 1:15 micelles, respectively, with drug loading capacities of 9.93 ± 0.21% and 6.91 ± 1.19%, and encapsulation efficiencies of 42.74 ± 1.67% and 73.29 ± 4.78%, respectively. The micelles provided sustained exposure and improved pharmacokinetics characterized by a significant increase in serum half-life, area under curve, and mean residence time. The micelles reduced vorinostat clearance particularly after i.v. dosing. Thus, PEG-b-PLA micelles significantly improved the p.o. and i.v. pharmacokinetics and bioavailability of vorinostat, which warrants further investigation. PMID:22806441

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  13. Plasmid-encapsulated polyethylene glycol-grafted polyethylenimine nanoparticles for gene delivery into rat mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Chen X

    2011-04-01

    Full Text Available Xiao-Ai Chen1,5*, Li-Jun Zhang2*, Zhi-Jie He3, Wei-Wei Wang4, Bo Xu1, Qian Zhong1, Xin-Tao Shuai4, Li-Qun Yang4, Yu-Bin Deng11Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China; 2Futian Affiliated Hospital, Guangdong Medical College, Shenzhen, China; 3Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China; 4Institute of Polymer Science, School of Chemistry and Chemical Engineering, BME Center, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou, China; 5Yunnan Cancer Hospital, The Third Affiliated Hospital, Kunming Medical College, Kunming, China*Both authors contributed equally to this workBackground: Mesenchymal stem cell transplantation is a promising method in regenerative medicine. Gene-modified mesenchymal stem cells possess superior characteristics of specific tissue differentiation, resistance to apoptosis, and directional migration. Viral vectors have the disadvantages of potential immunogenicity, carcinogenicity, and complicated synthetic procedures. Polyethylene glycol-grafted polyethylenimine (PEG-PEI holds promise in gene delivery because of easy preparation and potentially targeting modification.Methods: A PEG8k-PEI25k graft copolymer was synthesized. Agarose gel retardation assay and dynamic light scattering were used to determine the properties of the nanoparticles. MTT reduction, wound and healing, and differentiation assays were used to test the cytobiological characteristics of rat mesenchymal stem cells, fluorescence microscopy and flow cytometry were used to determine transfection efficiency, and atomic force microscopy was used to evaluate the interaction between PEG-PEI/plasmid nanoparticles and mesenchymal stem cells.Results: After incubation with the copolymer, the bionomics of mesenchymal stem cells showed no significant change. The mesenchymal stem cells still maintained high viability, resettled the

  14. Effect of polyethylene glycol on pore structure and separation efficiency of silica-based monolithic capillary columns.

    Science.gov (United States)

    Hara, Takeshi; Desmet, Gert; Baron, Gino V; Minakuchi, Hiroyoshi; Eeltink, Sebastiaan

    2016-04-15

    Monolithic silica materials (first unclad monolith rods, then monolithic capillary columns) were prepared using various amounts of polyethylene glycols (PEGs) with different molecular weight (MW). The monolith rods were used to examine the mesoporosity by argon physisorption technique, and the macroporosity by mercury intrusion porosimetry. Subsequently, silica-based monolithic capillary columns with an inner diameter of 100 μm were produced using the same preparation conditions as used for the rods. The results obtained with the monolith rods showed the following important findings: (1) it is feasible to fabricate monolithic silica rods possessing macropore size of 0.5-1.4 μm by tuning the amount of PEGs (independently of the MW), whereas the macropore volume and the mesoporosity remain similar. (2) the smallest macropore size (0.5 μm) rod prepared with PEG having a MW=20,000g/mol provided a narrower macropore size distribution than with PEG with MW=10,000g/mol. The monolithic capillary columns produced with the different PEG type showed similar retention factors for hexylbenzene (k=2.3-2.4) and similar t0-based column permeability (Kv0=2.3-2.4×10(-14)m(2)) in 20:80% (v/v) water:methanol, as expected from the results obtained with the monolith rods. The column prepared with PEG of MW=20,000g/mol gave a plate height of H=4.0 μm for hexylbenzene at an optimal linear velocity of u0=2.6mm/s in 20:80% (v/v) water containing 0.1% formic acid:acetonitrile. To the best of our knowledge, this is the lowest plate height ever recorded for a monolithic column. Comparing the kinetic performance at 30MPa shows that the best monolithic silica column obtained in the present study performs better than the second-generation monolithic silica columns developed up till now in the practically most relevant range of plate numbers (N≤40,000). In this range, the performance is now similar to that of 2.7 μm core-shell particle columns. PMID:26976349

  15. Increase of thyroid stimulating activity in Graves' immunoglobulin-G by high polyethylene glycol concentrations using porcine thyroid cell assay.

    Science.gov (United States)

    Inui, T; Kouki, T; Yamashiro, K; Hachiya, T; Ochi, Y; Kajita, Y; Sato, Y; Nagata, A

    1998-04-01

    Cyclic adenosine monophosphate (cAMP) production during a 5-hour incubation using porcine thyroid cells (PTC) was stimulated significantly more by polyethylene glycol (PEG) 22.5% precipitated fractions (ppt frs) than by PEG 12.5% ppt frs from almost all Graves' sera. However, the thyrotropin (TSH) binding inhibition (TBI) activities of the PEG 12.5% and 22.5% ppt frs using porcine thyroid membranes were similar, and did not change in the 5-hour incubation. When the PEG 12.5% ppt fr from Graves' serum and the PEG 22.5% ppt fr from normal human serum (NHS) were coincubated, cAMP production was also stimulated as much as by the PEG 22.5% ppt fr from Graves' serum. When purified thyroid stimulating antibody (TSAb)-immunoglobulin G (IgG) and the PEG 22.5% ppt fr from NHS were coincubated, increased cAMP production was also observed, whereas bovine thyrotropin (bTSH) did not produce this effect. When purified TSAb-IgG and PEG solutions were coincubated, maximum increases in cAMP production (approximately 10-fold) with 5% PEG were found, whereas no increase was observed using bTSH. The stimulatory effect of high PEG concentrations on thyroid stimulating activity was observed by TSAb-IgG in salt-free or salt-containing medium (<0.15 mol/L NaCl concentration) but not by either TSAb-IgG conjugated to protein A-sepharose 4B or the inactivated TSAb-IgG by the treatment of 70 degrees C for 10 minutes. No stimulatory action by PEG was found with the thyroid stimulating substances such as GTPgammaS, forskolin, or pituitary adenylate-cyclase activating polypeptide (PACAP). The increased thyroid stimulating activity of Graves (IgG) at high PEG concentrations suggests the existence of some factors influencing the ability of TSAb to stimulate thyroid cells, although the exact mechanism remains to be clarified. PMID:9588497

  16. Sensitive thyroid-stimulating antibody assay in whole serum containing five percent polyethylene glycol using porcine thyroid cells.

    Science.gov (United States)

    Ochi, Y; Kajita, Y; Inui, T; Yamashiro, K; Takasu, N; Sato, Y; Nagata, A

    2000-08-01

    Previously we reported that the amounts of cyclic adenosine monophosphate (cAMP) production by polyethylene glycol (PEG) 22.5% precipitated fraction (PF) (crude immunoglobulin G [IgG]) from thyroid-stimulating antibody (TSAb)-positive serum were higher than those by PEG 12.5% PF, and that PEG (5%) augmented affinity purified TSAb-IgG-stimulated cAMP production in porcine thyroid cells (PTC) assay. In the present work, we studied sensitive TSAb assay using whole sera in the presence of high PEG concentrations in PTC assay. cAMP produced by TSAb-positive serum increased in proportion to serum amounts up to 0.05 mL, but gradually decreased in 0.075 mL. The maximal augmentative effect of PEG on TSAb-positive serum (0.05 mL)-stimulated cAMP production was found in 5% PEG (final). Thus, TSAb assay using whole serum (0.05 mL) in the absence of 5% PEG (serum method) and sensitive TSAb (sTSAb) assay using whole serum (0.05 mL) in the presence of 5% PEG (serum plus 5% PEG method) were performed. The sensitive thyroid-stimulating antibody (sTSAb) activities of Graves' sera showed significantly higher (twofold to sevenfold) compared to simple TSAb activity with sera. sTSAb and TSAb activities were positive in 91% (29/32) and 47% (15/32) of untreated Graves' patients with hyperthyroidism. The sTSAb activities by serum plus 5% PEG method were higher than that by PEG 12.5% precipitated fraction (PF) from test serum (0.2 mL) in many Graves' sera, but lower than that by PEG 22.5% PF from test serum (0.2 mL). PEG (5%) did not augment cAMP produced by high TSH serum (127-210 mU/L) in thyroiditis chronica. sTSAb activity was negative in adenomatous goiter, subacute thyroiditis, and thyroid cancer. sTSAb activity was also negative in TSH stimulation blocking antibody (TSBAb)-positive hypothyroidism (during thyroxine [T4] treatment), but was positive in Graves' sera with coexistence serum of TSAb and TSBAb because of augmentative effect of 5% PEG on TSAb activity. This assay in whole

  17. Synthesis and characterization of polyester copolymers based on poly(butylene succinate) and poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2012-12-01

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, {sup 1}HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (T{sub m}), crystallization temperature (T{sub c}), and crystallinity (X{sub c}) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the {sup 1}H NMR spectra using the relative intensities of the proton peaks. As a sample, the {sup 1}H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH{sub 2}){sub 2}-CO; O-CH{sub 2}- and C-(CH{sub 2}){sub 2}-C from the SA and BD unit at {delta}2.59; {delta} 4.08 and {delta}1.67; O-(CH{sub 2}CH{sub 2}){sub n}-O from the PEG unit at {delta} 3.61. The molar composition of polyester copolymer was measured as the area ratio of {delta}3.61/({delta}4.08 + {delta}1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: Black-Right-Pointing-Pointer The introduction of PEG unit changed the flexibility of PBS main chain. Black-Right-Pointing-Pointer PEG unit did not alter the crystal form of PBS in copolymers. Black-Right-Pointing-Pointer PEG unit hindered the formation of ring-banded spherulite morphology in copolymers

  18. Synthesis and characterization of polyester copolymers based on poly(butylene succinate) and poly(ethylene glycol)

    International Nuclear Information System (INIS)

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, 1HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (Tm), crystallization temperature (Tc), and crystallinity (Xc) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the 1H NMR spectra using the relative intensities of the proton peaks. As a sample, the 1H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH2)2-CO; O-CH2- and C-(CH2)2-C from the SA and BD unit at δ2.59; δ 4.08 and δ1.67; O-(CH2CH2)n-O from the PEG unit at δ 3.61. The molar composition of polyester copolymer was measured as the area ratio of δ3.61/(δ4.08 + δ1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: ► The introduction of PEG unit changed the flexibility of PBS main chain. ► PEG unit did not alter the crystal form of PBS in copolymers. ► PEG unit hindered the formation of ring-banded spherulite morphology in copolymers. ► The copolyesters had good in vitro degradation performance. ► The composition ratio of PEG unit can adjust the in vitro degradation performance.

  19. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Science.gov (United States)

    Li, Xiaomeng; Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

    2012-01-01

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  20. 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

    KAUST Repository

    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.

  1. Intraperitoneal administration of high doses of polyethylene glycol (PEG) causes hepatic subcapsular necrosis and low-grade peritonitis with a rise in hepatic biomarkers

    International Nuclear Information System (INIS)

    Polyethylene glycols (PEGs) are commonly employed as excipients in preclinical studies and in vitro experiments to dissolve poorly hydrosoluble drugs. Their use is generally considered safe in both animals and humans; however, limited data is available concerning the safety of PEGs when administered parenterally. The results of our investigation demonstrate that PEG-400 can have an irritant effect on serosal surfaces and causes subcapsular hepatocellular necrosis in mice when administered intraperitoneally at a high dose (4 mL/kg). Accordingly, levels of serum biomarkers of liver injury need to be carefully interpreted in studies where PEG is administered intraperitoneally and always in association with the results of the histological assessment

  2. Supramolecular Functionalities Influence the Thermal Properties, Interactions and Conductivity Behavior of Poly(ethylene glycol)/LiAsF6 Blends

    OpenAIRE

    Shiao-Wei Kuo; Chih-Chia Cheng; Feng-Chih Chang; Oleksii Altukhov; Jui-Hsu Wang

    2013-01-01

    In this study, we tethered terminal uracil groups onto short-chain poly(ethylene glycol) (PEG) to form the polymers, uracil (U)-PEG and U-PEG-U. Through AC impedance measurements, we found that the conductivities of these polymers increased upon increasing the content of the lithium salt, LiAsF6, until the Li-to-PEG ratio reached 1:4, with the conductivities of the LiAsF6/U-PEG blends being greater than those of the LiAsF6/U-PEG-U blends. The ionic conductivity of the LiAsF6/U-PEG system reac...

  3. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan Shifang, E-mail: sfluan@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yang Huawei; Shi Hengchong; Zhao Jie; Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-01-15

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  4. 聚乙二醇相转移催化法合成查耳酮%Synthesis of Chalcone with Phase Transfer Catalyst Polyethylene Glycol

    Institute of Scientific and Technical Information of China (English)

    蒋新宇; 赵爱丽

    2006-01-01

    以聚乙二醇(polyethylene glycol,PEG)为相转移催化剂进行了苯甲醛与苯乙酮的克莱森-施密特(Claisen-Schmidt)缩合反应,并就聚乙二醇用量、聚乙二醇相对分子质量和溶剂种类等影响因素进行了条件实验,在较优化的合成条件下,查耳酮产率可达80%.

  5. Synthesis by High-Efficiency Liquid-Phase (HELP Method of Oligonucleotides Conjugated with High-Molecular Weight Polyethylene Glycols (PEGs

    Directory of Open Access Journals (Sweden)

    Bonora GM

    1998-01-01

    Full Text Available The chemical modification of synthetic oligonucleotides has recently been investigated to improve their pharmacological utilization. In addition to chemical alterations of the backbone and of the heterocyclic bases, their conjugation with amphiphylic moieties, such as the polyethylene glycol has been proposed. The large scale production of these molecules as demanded for commercial purposes is hampered by the heterogeneity of the solid-phase processes and by the low reactivity of high-molecular weight PEGs in solution. A new synthetic procedure based on the recently developed liquid-phase method (HELP, has been set up to overcome these limitations.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    seeds at 25°C, a thermoinhibitory temperature. Before twodimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two...... the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination...

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

    Directory of Open Access Journals (Sweden)

    Qiu JF

    2013-08-01

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

  8. Pectinases partitioning in aqueous two-phase systems: an integration of the systems poly(ethylene glycol/crude dextran and poly(ethylene glycol/ammonium sulphate

    Directory of Open Access Journals (Sweden)

    NIKOLA VUKELIC

    2004-04-01

    Full Text Available The reaction of Pd(II with 1,8-dihydroxy-2-(pyrazol-5-ylazo-naphthalene-3-6-disulphonic acid (PACA sorbed onto Dowex 1-X8 ion-exchange resin was investigated with the aim of developing an absorption-spectrophotometric analytical method for the determination of low Pd(II concentrations in water. The immobilized reagent formed a 1:1 complex with Pd(II having an absorption maximum at 650 nm. Parameters, such as pH, wavelength and contact time were optimised for a given amount of the sorbed reagent. The linearity range of absorbance vs. Pd(II concentration extended from 5×10-6 – 5×10-5 M, 5×10-7 – 5×10-6 and 2.5×10-8 – 2.5×10-7 M when using 10, 100 and 200 ml of sample solution, respectively. With a 200 ml sample, the detection limit was 2.5×10-7 M Pd(II. Most metals, except Cu(II, did not interfere when present in up to 100 times the concentration of Pd(II.

  9. Calculation of NaCl, KCl and LiCl Salts Activity Coefficients in Polyethylene Glycol (PEG4000)-Water System Using Modified PHSC Equation of State, Extended Debye-Hückel Model and Pitzer Model

    Science.gov (United States)

    Marjani, Azam

    2016-07-01

    For biomolecules and cell particles purification and separation in biological engineering, besides the chromatography as mostly applied process, aqueous two-phase systems (ATPS) are of the most favorable separation processes that are worth to be investigated in thermodynamic theoretically. In recent years, thermodynamic calculation of ATPS properties has attracted much attention due to their great applications in chemical industries such as separation processes. These phase calculations of ATPS have inherent complexity due to the presence of ions and polymers in aqueous solution. In this work, for target ternary systems of polyethylene glycol (PEG4000)-salt-water, thermodynamic investigation for constituent systems with three salts (NaCl, KCl and LiCl) has been carried out as PEG is the most favorable polymer in ATPS. The modified perturbed hard sphere chain (PHSC) equation of state (EOS), extended Debye-Hückel and Pitzer models were employed for calculation of activity coefficients for the considered systems. Four additional statistical parameters were considered to ensure the consistency of correlations and introduced as objective functions in the particle swarm optimization algorithm. The results showed desirable agreement to the available experimental data, and the order of recommendation of studied models is PHSC EOS > extended Debye-Hückel > Pitzer. The concluding remark is that the all the employed models are reliable in such calculations and can be used for thermodynamic correlation/predictions; however, by using an ion-based parameter calculation method, the PHSC EOS reveals both reliability and universality of applications.

  10. 椰油丙基酰胺甜菜碱/聚乙二醇水溶液的分相研究%Phase Separation Behavior of Cocamidopropyl Betaine/Water/Polyethylene Glycol System

    Institute of Scientific and Technical Information of China (English)

    游晓艳; 秦炜; 戴猷元

    2009-01-01

    Phase separation behavior of cocamidopropyl betaine/water/polyethylene glycol (PEG) system was studied. The effects of concentration and molecular weight of PEG on the phase separation behavior were investigated. Clouding occurred when the concentration of PEG was large enough in the betaine aqueous solution, and the concentration of PEG at cloud point decreased with the increase of PEG molecular weight for a constant betaine concentration. The bottom phase was the PEG-rich phase, and the upper phase was the betaine-rich phase. The volumetric ratio of PEG-rich phase to betaine-rich phase, at the same difference between the PEG concentration and the one at the cloud point, ΔC_(cp) (0.1 g·ml~(-1) ), decreased as the PEG molecular weight increased and approached 1 for higher PEG molecular weight (about 20000), which was similar to the typical aqueous two-phase system. This volumetric ratio depended on the initial PEG concentration, but independent of PEG molecular weight. The concentration ratio of betaine to PEG in both phases depended on the ΔC_(cp), independent of PEG molecular weight.

  11. Direct laser writing of synthetic poly(amino acid) hydrogels and poly(ethylene glycol) diacrylates by two-photon polymerization

    International Nuclear Information System (INIS)

    The additive manufacturing technique of direct laser writing by two-photon polymerization (2PP-DLW) enables the fabrication of three-dimensional microstructures with superior accuracy and flexibility. When combined with biomimetic hydrogel materials, 2PP-DLW can be used to recreate the microarchitectures of the extracellular matrix. However, there are currently only a limited number of hydrogels applicable for 2PP-DLW. In order to widen the selection of synthetic biodegradable hydrogels, in this work we studied the 2PP-DLW of methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s). The performance of these materials was compared to widely used poly(ethylene glycol) diacrylates (PEGdas) in terms of polymerization and damage thresholds, voxel size, line width, post-polymerization swelling and deformation. We found that both methacryloylated and acryloylated poly(AA) hydrogels are suitable to 2PP-DLW with a wider processing window than PEGdas. The poly(AA) with the highest degree of acryloylation showed the greatest potential for 3D microfabrication. - Highlights: • Methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s) were synthesized. • Direct laser writing by two-photon polymerization (2PP-DLW) of poly(AA)s is shown. • Poly(AA)s have wider processing windows than poly(ethylene glycol) diacrylates. • 3D poly(AA) structures with 80% water content were fabricated

  12. Investigating the stability of the nonionic surfactants tocopheryl polyethylene glycol succinate and sucrose laurate by HPLC-MS, DAD, and CAD.

    Science.gov (United States)

    Christiansen, Anne; Backensfeld, Thomas; Kühn, Silke; Weitschies, Werner

    2011-05-01

    High-performance liquid chromatography (HPLC) methods using a charged aerosol detector (CAD), a mass selective detector (MSD), and a diode array detector (DAD) were developed to characterize the nonionic surfactants d-α-tocopheryl polyethylene glycol (1000) succinate (TPGS) and Surfhope sugar ester D-1216 (sucrose laurate). The molecular structure and the heterogeneous composition resulting from different isomers and various lengths of polyethylene glycol (PEG) chains make it difficult to develop sensitive and specific analytical methods for both surfactants. Hence, there is lack of knowledge about the stability and grade of impurity of these compounds. Sucrose laurate does not possess any chromophore, thus UV detection is not applicable. Therefore, CAD and MSD have been used for determination. The aim of the study was to characterize these nonionic surfactants and to examine chemical stability at pH 1.0 and 37 °C, simulating harsh gastric conditions. It was shown that both compounds are liable to degradation under these conditions. Sucrose monolaurate exhibited a massive degradation within 8 h incubation due to cleavage of the glycosidic bondage. About 50% of sucrose monolaurate broke down, whereas a marginal amount of 3.4% (± 0.4%) of TPGS degraded into d-α-tocopheryl succinate and the associated PEG chain. PMID:21374613

  13. Poly(ethylene glycol) dicarboxylate/poly(ethylene oxide) hydrogel film co-crosslinked by electron beam irradiation as an anti-adhesion barrier.

    Science.gov (United States)

    Haryanto; Singh, Deepti; Han, Sung Soo; Son, Jun Hyuk; Kim, Seong Cheol

    2015-01-01

    The cross-linked poly(ethylene glycol) dicarboxylate (PEGDC)/poly(ethylene oxide) (PEO) and poly(ethylene glycol) dimethacrylate (PEGDMA)/(PEO) hydrogels were developed for possible biomedical applications such as an anti-adhesion barrier. Various contents of PEGDC/PEO film were irradiated using an electron beam with various beam intensities in order to obtain various degrees of crosslinked hydrogels. The optimum dose (300 kGy) and total crosslinker content of 10% were used to prepare crosslinked hydrogel films with three different compositions (10% PEGDC, 10% PEGDMA, 5% PEGDC-5% PEGDMA). Among them, 10% PEGDC hydrogel film exhibited the highest elongation at break (69.33±6.87%) with high mechanical strength. 10% PEGDC hydrogel film showed the lowest hemolysis activity (6.03±0.01%) and the highest tissue adherence (75.67±1.15 cN). The result also indicated that the carboxyl groups in PEGDC affect the tissue adherence of hydrogel films via H-bonding interactions. In animal studies, 10% PEGDC anti-adhesion hydrogel film degraded within 3 weeks and demonstrated better anti-adhesive effect compared to Guardix-SG®. PMID:25491977

  14. Preventing adhesion of Escherichia coli O157:H7 and Salmonella Typhimurium LT2 on tomato surfaces via ultrathin polyethylene glycol film.

    Science.gov (United States)

    Zhang, Ming; Yang, Fan; Pasupuleti, Sasikiran; Oh, Jun Kyun; Kohli, Nandita; Lee, I-Syuan; Perez, Keila; Verkhoturov, Stanislav V; Schweikert, Emile A; Jayaraman, Arul; Cisneros-Zevallos, Luis; Akbulut, Mustafa

    2014-08-18

    This work deals with adhesion of Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium LT2 (S. Typhimurium LT2) on polyethylene glycol (PEG) coated tomato surfaces. PEG coating was characterized by water contact angle technique, scanning electron microscopy, and secondary ion mass spectrometry. It was shown that PEG films could physisorb on the tomato surfaces after the oxygen plasma treatment, which made some outermost layers of the surfaces hydrophilic. Bacterial adhesion on PEG coated tomato surface was studied by standard plate count, fluorescence microscopy, and scanning electron microscopy techniques. Fully covered PEG film reduced the bacterial attachment 90% or more in comparison to the bare tomato surface. The degree of bacterial attachment decreased exponentially with increasing PEG coverage. When desired, PEG film could be removed by rinsing with water. Overall, this work demonstrates the proof-of-concept that an ultrathin film of polyethylene glycol may be used to effectively inhibit the attachment of pathogenic bacteria on tomato surfaces.

  15. Solubility of high-value compounds in environmentally friendly solvents–liquid poly(ethylene glycol) and ionic liquids: Experimental study and thermodynamic analysis

    International Nuclear Information System (INIS)

    Highlights: • Liquid poly(ethylene glycol) (PEG) and ionic liquids were tested as solvents for five high-value compounds. • Solubility of thymol, ferulic acid, vanillic acid, caffeic acid and caffeine, in liquid PEG and ionic liquids is studied. • Liquid PEG200 and PEG400 and ionic liquid [C4mim][OTf] showed as good solvents for the high value compounds. -- Abstract: In this work the (solid + liquid) equilibria (SLE) of the solution of sustainable solvents with five high-value compounds, thymol, ferulic acid, vanillic acid, caffeic acid and caffeine, was investigated. The sustainable solvents studied were liquid poly(ethylene glycol) of average molecular mass 200 and 400 – (PEG200 and PEG400), respectively as well as imidazolium ionic liquids with bistriflamide and triflate anions ([C4mim][NTf2] and [C4mim][OTf]). The obtained SLE data were correlated using the semi-empirical equation proposed by Grant. The activity coefficients of the studied solutes were calculated. Based on these correlations and calculations as well as on the thermo-physical properties of the pure constituents, the SLE behavior of the studied solutions was analyzed and discussed

  16. Direct laser writing of synthetic poly(amino acid) hydrogels and poly(ethylene glycol) diacrylates by two-photon polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Käpylä, Elli, E-mail: elli.kapyla@tut.fi [Department of Electronics and Communications Engineering, Tampere University of Technology, P.O. Box 692, 33101 Tampere (Finland); BioMediTech, Biokatu 10, 33520 Tampere (Finland); Sedlačík, Tomáš [Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6, Břevnov, Prague (Czech Republic); Aydogan, Dogu Baran [Department of Electronics and Communications Engineering, Tampere University of Technology, P.O. Box 692, 33101 Tampere (Finland); BioMediTech, Biokatu 10, 33520 Tampere (Finland); Viitanen, Jouko [VTT Technical Research Centre of Finland, P.O. Box 1300, 33101 Tampere (Finland); Rypáček, František [Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6, Břevnov, Prague (Czech Republic); Kellomäki, Minna [Department of Electronics and Communications Engineering, Tampere University of Technology, P.O. Box 692, 33101 Tampere (Finland); BioMediTech, Biokatu 10, 33520 Tampere (Finland)

    2014-10-01

    The additive manufacturing technique of direct laser writing by two-photon polymerization (2PP-DLW) enables the fabrication of three-dimensional microstructures with superior accuracy and flexibility. When combined with biomimetic hydrogel materials, 2PP-DLW can be used to recreate the microarchitectures of the extracellular matrix. However, there are currently only a limited number of hydrogels applicable for 2PP-DLW. In order to widen the selection of synthetic biodegradable hydrogels, in this work we studied the 2PP-DLW of methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s). The performance of these materials was compared to widely used poly(ethylene glycol) diacrylates (PEGdas) in terms of polymerization and damage thresholds, voxel size, line width, post-polymerization swelling and deformation. We found that both methacryloylated and acryloylated poly(AA) hydrogels are suitable to 2PP-DLW with a wider processing window than PEGdas. The poly(AA) with the highest degree of acryloylation showed the greatest potential for 3D microfabrication. - Highlights: • Methacryloylated and acryloylated poly(α-amino acid)s (poly(AA)s) were synthesized. • Direct laser writing by two-photon polymerization (2PP-DLW) of poly(AA)s is shown. • Poly(AA)s have wider processing windows than poly(ethylene glycol) diacrylates. • 3D poly(AA) structures with 80% water content were fabricated.

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

    Directory of Open Access Journals (Sweden)

    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

  18. Polyethylene; Polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-03-01

    Petrochina has chosen the Lupotech T technology of Basell for its use in a low density polyethylene unit of 200000 t/year which should be constructed in Lanzhou (China) for an amount of 82 M of Euros. PTT and its sub-company Thai Olefins are discussing for the repurchase of the firm Bangkok Polyethylene specialized in the high density polyethylene with a capacity of 250000 t/year. Basell should close more than 300000 t/year of capacities of high density polyethylene in Europe. (O.M.)

  19. Supramolecular recognition control of polyethylene glycol modified N-doped graphene quantum dots: tunable selectivity for alkali and alkaline-earth metal ions.

    Science.gov (United States)

    Yang, Siwei; Sun, Jing; Zhu, Chong; He, Peng; Peng, Zheng; Ding, Guqiao

    2016-02-01

    The graphene quantum dot based fluorescent probe community needs unambiguous evidence about the control on the ion selectivity. In this paper, polyethylene glycol modified N-doped graphene quantum dots (PN-GQDs) were synthesized by alkylation reaction between graphene quantum dots and organic halides. We demonstrate the tunable selectivity and sensitivity by controlling the supramolecular recognition through the length and the end group size of the polyether chain on PN-GQDs. The relationship formulae between the selectivity/detection limit and polyether chains are experimentally deduced. The polyether chain length determines the interaction between the PN-GQDs and ions with different ratios of charge to radius, which in turn leads to a good selectivity control. Meanwhile the detection limit shows an exponential growth with the size of end groups of the polyether chain. The PN-GQDs can be used as ultrasensitive and selective fluorescent probes for Li(+), Na(+), K(+), Mg(2+), Ca(2+) and Sr(2+), respectively. PMID:26730814

  20. Anti-tumor activity and immunological modification of ribosome-inactivating protein (RIP) from Momordica charantia by covalent attachment of polyethylene glycol

    Institute of Scientific and Technical Information of China (English)

    Mengen Li; Yiwen Chen; Zhongyu Liu; Fubing Shen; Xiaoxiao Bian; Yanfa Meng

    2009-01-01

    Ribosome-inactivating proteins (RIPs) are a family of enzymes that depurinate rRNA and inhibit protein biosynthesis. Here we report the purification, apoptosis-inducing activity, and polyethylene glycol (PEG) modification of RIP from the bitter melon seeds. The protein has a homogenous N-terminal sequence of N-Asp-Val-Ser-Phe-Arg. Moreover, the RIP displayed strong apoptosis-inducing activity and suppressed cancer cell growth. This might be attributed to the acti-vation of caspases-3. To make it available for in vivo application, the immunogenicity of RIP was reduced by chemical modification with 20 kDa (mPEG)2-Lys-NHS. The inhibition activity of both PEGylated and non-PEGylated RIP against cancer cells was much stronger than against normal cells, and the antigenicity of PEGylated RIP was reduced significantly. Our results suggested that the PEGylated RIP might be potentially developed as anti-cancer drug.

  1. A 3D Poly(ethylene glycol)-based Tumor Angiogenesis Model to Study the Influence of Vascular Cells on Lung Tumor Cell Behavior

    Science.gov (United States)

    Roudsari, Laila C.; Jeffs, Sydney E.; Witt, Amber S.; Gill, Bartley J.; West, Jennifer L.

    2016-09-01

    Tumor angiogenesis is critical to tumor growth and metastasis, yet much is unknown about the role vascular cells play in the tumor microenvironment. In vitro models that mimic in vivo tumor neovascularization facilitate exploration of this role. Here we investigated lung adenocarcinoma cancer cells (344SQ) and endothelial and pericyte vascular cells encapsulated in cell-adhesive, proteolytically-degradable poly(ethylene) glycol-based hydrogels. 344SQ in hydrogels formed spheroids and secreted proangiogenic growth factors that significantly increased with exposure to transforming growth factor beta 1 (TGF-β1), a potent tumor progression-promoting factor. Vascular cells in hydrogels formed tubule networks with localized activated TGF-β1. To study cancer cell-vascular cell interactions, we engineered a 2-layer hydrogel with 344SQ and vascular cell layers. Large, invasive 344SQ clusters (area > 5,000 μm2, circularity culture system as a platform for studying tumor vascularization.

  2. Application of poly(ethylene glycol)-distearoylphosphatidylethanolamine (PEG-DSPE) block copolymers and their derivatives as nanomaterials in drug delivery.

    Science.gov (United States)

    Wang, Rongrong; Xiao, Renzhong; Zeng, Zhaowu; Xu, Lili; Wang, Junjie

    2012-01-01

    Poly(ethylene glycol)-distearoylphosphatidylethanolamine (PEG-DSPE) block copolymers are biocompatible and amphiphilic polymers that can be widely utilized in the preparation of liposomes, polymeric nanoparticles, polymer hybrid nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, and microemulsions. Particularly, the terminal groups of PEG can be activated and linked to various targeting ligands, which can prolong the circulation time, improve the drug bioavailability, reduce undesirable side effects, and especially target specific cells, tissues, and even the intracellular localization in organelles. This review herein aims to describe recent developments in drug carriers exploiting PEG-DSPE block copolymers and their derivatives, and the incorporation of different ligands to the end groups of PEG-DSPE to target delivery, focusing on their modification approaches, advantages, applications, and the probable associated drawbacks. PMID:22904628

  3. Polyethylene Glycols as Efficient Media for Decarboxylative Nitration of α,β-Unsaturated Aromatic Carboxylic Acids by Ceric Ammonium Nitrate in Acetonitrile Medium: A Kinetic and Mechanistic Study

    Directory of Open Access Journals (Sweden)

    K. Ramesh

    2013-01-01

    Full Text Available Polyethylene glycols (PEGs were found to be efficient media for decarboxylative nitration of α,β-unsaturated aromatic carboxylic acids by ceric ammonium nitrate (CAN in acetonitrile to give β-nitrostyrene derivatives. Kinetics of the reaction exhibited second order kinetics with a first order dependence on [CAN] and [substrate]. Reactions were too sluggish to be studied in the absence of PEG; therefore detailed kinetics were not taken up. Reaction times were reduced from 24 hrs to few hours. The catalytic activity was found to be in the increasing order PEG-300 > PEG-400 > PEG-600 > PEG-200. Mechanism of PEG-mediated reactions was explained by Menger-Portnoy's scheme as applied in micellar kinetics.

  4. Effects of La0.2Ce0.6Eu0.2F3 nanoparticles capped with polyethylene glycol on human astrocytoma cells in vitro

    Science.gov (United States)

    Withers, Nathan J.; Brandt, Yekaterina; Rivera, Antonio C.; Armijo, Leisha M.; Cook, Nathaniel C.; Osiński, Marek

    2012-03-01

    Lanthanide fluoride colloidal nanocrystals offer a way to improve the diagnosis and treatment of cancer through the enhanced absorption of ionizing radiation, as well as providing visible luminescence. In order to explore this possibility, cytotoxicity assays need to be performed on mammalian cells in vitro, to show minimum levels of biocompatibility for future experiments. 20% lanthanum 60% cerium and 20% europium lanthanide fluoride nanocrystals were capped with polyethylene glycol (PEG) of molecular weight 4000 and suspended in deionized water. These nanocrystals were characterized by transmission electron microscopy, muffle furnace ashing, absorbance spectroscopy, dynamic light scattering, and photoluminescence spectroscopy. Visible light microscopy and trypan blue staining was performed on the cells to assay the cytotoxicity of the nanocrystal on the human astrocytoma line U-87 MG, purchased from ATCC.

  5. Investigation of Structure and Properties of Biodegradable Compositions of Polylactide with Ethyl Cellulose and Chitosan Plasticized by Poly(Ethylene Glycol

    Directory of Open Access Journals (Sweden)

    Rogovina Svetlana Zakharovna

    2014-12-01

    Full Text Available Compositions of polylactide (PLA with polysaccharides ethyl cellulose and chitosan are obtained at different initial ratios of components under conditions of shear deformation in a Brabender mixer. It has been shown that the addition of a given amount of low-molecular poly(ethylene glycol (PEG leads to an increase in the elongation of rigid polysaccharide–PLA compositions. The influence of molecular weight and amount of PEG on the thermal behavior of PLA is investigated by DSC method. The biodegradability of films prepared from the blends under investigation is estimated by weight loss after holding in soil and tests on the fungus resistance, and it is shown that the compositions have good biodegradability. The changes in the film morphology after holding in soil revealed by the SEM method additionally confirm that compositions are subjected to biodegradation.

  6. Optical Properties of Afterglow Nanoparticles Sr2MgSi2O7: Eu2+, Dy3+ Capped with Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    Fumitaka Yoshimura

    2012-01-01

    Full Text Available The optical properties of afterglow nanoparticles were successfully improved by the addition of polyethylene glycol (PEG to an afterglow colloidal solution. Afterglow nanoparticles—Sr2MgSi2O7: Eu2+, Dy3+—were prepared by laser ablation in liquid. The quantum yields and the decay curves were measured by a fluorescence spectrophotometer. An increase in the amount of PEG added to the solution increased the quantum yield of the nanoparticles and improved the afterglow property in the initial portion of the decay curve. However, the afterglow property did not change after a substantial amount of time had passed. The afterglow nanoparticles were capped with PEG molecules, and surface defects of the nanoparticles were passivated, which decreased the optical properties.

  7. Arginine-glycine-aspartic acid-polyethylene glycol-polyamidoamine dendrimer conjugate improves liver-cell aggregation and function in 3-D spheroid culture.

    Science.gov (United States)

    Chen, Zhanfei; Lian, Fen; Wang, Xiaoqian; Chen, Yanling; Tang, Nanhong

    2016-01-01

    The polyamidoamine (PAMAM) dendrimer, a type of macromolecule material, has been used in spheroidal cell culture and drug delivery in recent years. However, PAMAM is not involved in the study of hepatic cell-spheroid culture or its biological activity, particularly in detoxification function. Here, we constructed a PAMAM-dendrimer conjugate decorated by an integrin ligand: arginine-glycine-aspartic acid (RGD) peptide. Our studies demonstrate that RGD-polyethylene glycol (PEG)-PAMAM conjugates can promote singly floating hepatic cells to aggregate together in a sphere-like growth with a weak reactive oxygen species. Moreover, RGD-PEG-PAMAM conjugates can activate the AKT-MAPK pathway in hepatic cells to promote cell proliferation and improve basic function and ammonia metabolism. Together, our data support the hepatocyte sphere treated by RGD-PEG-PAMAM conjugates as a potential source of hepatic cells for a biological artificial liver system. PMID:27621619

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

    Indian Academy of Sciences (India)

    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.

  9. Effects of La0.2Ce0.6Eu0.2F3 nanocrystals capped with polyethylene glycol on human pancreatic cancer cells in vitro

    Science.gov (United States)

    Withers, Nathan J.; Glazener, Natasha N.; Rivera, Antonio C.; Akins, Brian A.; Armijo, Leisha M.; Plumley, John B.; Cook, Nathaniel C.; Sugar, Jacqueline M.; Chan, Rana; Brandt, Yekaterina I.; Smolyakov, Gennady A.; Heintz, Philip H.; Osiński, Marek

    2013-02-01

    Lanthanide fluoride colloidal nanocrystals offer a way to improve the diagnosis and treatment of cancer through the enhanced absorption of ionizing radiation, in addition to providing visible luminescence. In order to explore this possibility, tests with a kilovoltage therapy unit manufactured by the Universal X-Ray Company were performed to estimate the energy sensitivity of this technique. La0.2Ce0.6Eu0.2F3 nanocrystals capped with polyethylene glycol of molecular weight 6000 were synthesized, suspended in deionized water, and made tolerant to biological ionic pressures by incubation with fetal bovine serum. These nanocrystals were characterized by dynamic light scattering, muffle furnace ashing, and photoluminescence spectroscopy. Clonogenic assays were performed on the cells to assay the cytotoxicity and radiotoxicity of the nanocrystals on the human pancreatic cancer cell line PANC-1, purchased from ATCC.

  10. MAGNOLOL ENTRAPPED ULTRA-FINE FIBROUS MATS ELECTROSPUN FROM POLY(ETHYLENE GLYCOL)-b-POLY(L-LACTIDE) AND IN VITRO RELEASE

    Institute of Scientific and Technical Information of China (English)

    Hao Wang; Hong-rui Song; Yong Cui; Ying-jie Deng; Xue-si Chen

    2011-01-01

    Ultra-fine fibrous mats with magnolol entrapped have been prepared by electrospinning biodegradable copolymer poly(ethylene glycol) blocked poly(L-lactide). Drug entrapment was perfect which was confirmed by scanning electron microscopy and differential scanning calorimetry. According to in vitro drug release investigation by high performance liquid chromatography, it was found that fibers with 10%, 20% and 30% drug entrapped respect to polymer (mass ratio) presented dramatically different drug release behavior and degradation behavior under the effect of proteinase K. The reason may be that fibers with 10% drug entrapped was more easily affected by enzyme while, to some degree, magnolol in fibers with 20% and 30% entrapped prevented polymer from being degraded by enzyme.

  11. A closed concept of extractive whole cell microbial transformation of benzaldehyde into L-phenylacetylcarbinol by Saccharomyces cerevisiae in novel polyethylene-glycol-induced cloud-point system.

    Science.gov (United States)

    Wang, Zhilong; Liang, Rui; Xu, Jian-He; Liu, Yubo; Qi, Hanshi

    2010-03-01

    Extractive microbial transformation of benzaldehyde into L-phenylacetylcarbinol (L-PAC) by Saccharomyces cerevisiae (Baker's yeast) has been carried out in a novel polyethylene-glycol-induced cloud-point system (PEG-CPS). The extractive microbial transformation in the PEG-CPS and a downstream process for stripping of the product from the microbial transformation broth with microemulsion extraction are demonstrated. The results indicate that the PEG-CPS maintains the advantage of CPS for in situ extraction of polar product in the microbial transformation. At the same time, the utilization of hydrophilic nonionic surfactant in the PEG-CPS is favorable for stripping of product from the nonionic surfactant in the microbial transformation broth by Winsor I microemulsion extraction. Thus, a closed concept of in situ extraction of polar product in microbial transformation and its downstream process of product recovery are fulfilled at the same time.

  12. Small-angle neutron scattering studies on water soluble complexes of poly(ethylene glycol)-based cationic random copolymer and SDS

    Indian Academy of Sciences (India)

    C K Nisha; V Manorama; Souvik Maiti; K N Jayachandran; V K Aswal; P S Goyal

    2004-08-01

    The interaction of cationic random copolymers of methoxy poly(ethylene glycol) monomethacrylate and (3-(methacryloylamino)propyl) trimethylammonium chloride with oppositely charged surfactant, sodium dodecyl sulphate, and the influence of surfactant association on the polymer conformation have been investigated by small-angle neutron scattering. SANS data showed a positive indication of the formation of RCP-SDS complexes. Even though the complete structure of the polyion complexes could not be ascertained, the results obtained give us the information on the local structure in these polymer-surfactant systems. The data were analysed using the log-normal distribution of the polydispersed spherical aggregate model for the local structure in these complexes. For all the systems the median radius and the polydispersity were found to be in the range of 20 ± 2 Å and 0:6 ± 0:05, respectively.

  13. Delayed hepatic uptake of multi-phosphonic acid poly(ethylene glycol) coated iron oxide measured by real-time Magnetic Resonance Imaging

    CERN Document Server

    Ramniceanu, G; Vezignol, C; Graillot, A; Loubat, C; Mignet, N; Berret, J -F

    2016-01-01

    We report on the synthesis, characterization, stability and pharmacokinetics of novel iron based contrast agents for magnetic resonance imaging (MRI). Statistical copolymers combining multiple phosphonic acid groups and poly(ethylene glycol) (PEG) were synthesized and used as coating agents for 10 nm iron oxide nanocrystals. In vitro, protein corona and stability assays show that phosphonic acid PEG copolymers outperform all other coating types examined, including low molecular weight anionic ligands and polymers. In vivo, the particle pharmacokinetics is investigated by monitoring the MRI signal intensity from mouse liver, spleen and arteries as a function of the time, between one minute and seven days after injection. Iron oxide particles coated with multi-phosphonic acid PEG polymers are shown to have a blood circulation lifetime of 250 minutes, i.e. 10 to 50 times greater than that of recently published PEGylated probes and benchmarks. The clearance from the liver takes in average 2 to 3 days and is indep...

  14. 'Pico-Bello-Klean study': effectiveness and patient tolerability of bowel preparation agents sodium picosulphate-magnesium citrate and polyethylene glycol before colonoscopy. A single-blinded randomized trial

    NARCIS (Netherlands)

    Munsterman, I.D.; Cleeren, E.; Ploeg, T. van der; Brohet, R.; Hulst, R van der

    2015-01-01

    OBJECTIVES: Adequate bowel preparation is an important step for an effective colonoscopy. Polyethylene glycol solution (Kleanprep) and sodium picosulphate with a magnesium citrate solution (Picoprep) are bowel cleansing agents registered and available for this purpose. So far, the results of studies

  15. Synthesis, Characterization and Biocompatibility of Biodegradable Elastomeric Poly(ether-ester urethane)s Based on Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and Poly(ethylene glycol) via Melting Polymerization

    DEFF Research Database (Denmark)

    Li, Zibiao; Yang, Xiaodi; Wu, Linping;

    2009-01-01

    Poly(ether-ester urethane)s (PUs) multiblock co-polymers were synthesized from telechelic hydroxylated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(ethylene glycol) (PEG) via a melting polymerization (MP) process using 1,6-hexamethylene diisocyanate (HDI) as a non-toxic coupling...

  16. Targeted polyethylene glycol gold nanoparticles for the treatment of pancreatic cancer: from synthesis to proof-of-concept in vitro studies

    Directory of Open Access Journals (Sweden)

    Spadavecchia J

    2016-02-01

    Full Text Available Jolanda Spadavecchia,1,2,* Dania Movia,3,* Caroline Moore,3,4 Ciaran Manus Maguire,3,4 Hanane Moustaoui,2 Sandra Casale,1 Yuri Volkov,3,4 Adriele Prina-Mello3,4 1Laboratoire de Réactivité de Surface, Sorbonne Universités, UPMC Univ Paris VI, Paris, 2Centre National de la recherche française, UMR 7244, CSPBAT, Laboratory of Chemistry, Structures, and Properties of Biomaterials and Therapeutic Agents, Université Paris 13, Sorbonne Paris Cité, Bobigny, France; 3AMBER Centre, CRANN Institute, 4Department of Clinical Medicine, School of Medicine, Trinity College, Dublin, Ireland *These authors contributed equally to this work Abstract: The main objective of this study was to optimize and characterize a drug delivery carrier for doxorubicin, intended to be intravenously administered, capable of improving the therapeutic index of the chemotherapeutic agent itself, and aimed at the treatment of pancreatic cancer. In light of this goal, we report a robust one-step method for the synthesis of dicarboxylic acid-terminated polyethylene glycol (PEG-gold nanoparticles (AuNPs and doxorubicin-loaded PEG-AuNPs, and their further antibody targeting (anti-Kv11.1 polyclonal antibody [pAb]. In in vitro proof-of-concept studies, we evaluated the influence of the nanocarrier and of the active targeting functionality on the anti-tumor efficacy of doxorubicin, with respect to its half-maximal effective concentration (EC50 and drug-triggered changes in the cell cycle. Our results demonstrated that the therapeutic efficacy of doxorubicin was positively influenced not only by the active targeting exploited through anti-Kv11.1-pAb but also by the drug coupling with a nanometer-sized delivery system, which indeed resulted in a 30-fold decrease of doxorubicin EC50, cell cycle blockage, and drug localization in the cell nuclei. The cell internalization pathway was strongly influenced by the active targeting of the Kv11.1 subunit of the human Ether-à-go-go related gene

  17. Modification of polyethylene glycol onto solid lipid nanoparticles encapsulating a novel chemotherapeutic agent (PK-L4 to enhance solubility for injection delivery

    Directory of Open Access Journals (Sweden)

    Fang YP

    2012-09-01

    Full Text Available Yi-Ping Fang,1 Pao-Chu Wu,2 Yaw-Bin Huang,3 Cherng-Chyi Tzeng,4 Yeh-Long Chen,4 Yu-Han Hung,2 Ming-Jun Tsai,5,6 Yi-Hung Tsai31Department of Biotechnology, Yuanpei University, Hsinchu, Taiwan; 2School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Graduate Institute of Clinical Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan; 4School of Medicinal and Applied Chemistry, College of Life Science, Kaohsiung Medical University, Kaohsiung, Taiwan; 5Department of Neurology, China Medical University Hospital, Taichung, Taiwan; 6School of Medicine, Medical College, China Medical University, Taichung, TaiwanBackground: The synthetic potential chemotherapeutic agent 3-Chloro-4-[(4-methoxyphenylamino]furo[2,3-b]quinoline (PK-L4 is an analog of amsacrine. The half-life of PK-L4 is longer than that of amsacrine; however, PK-L4 is difficult to dissolve in aqueous media, which is problematic for administration by intravenous injection.Aims: To utilize solid lipid nanoparticles (SLNs modified with polyethylene glycol (PEG to improve the delivery of PK-L4 and investigate its biodistribution behavior after intravenous administration.Results: The particle size of the PK-L4-loaded SLNs was 47.3 nm and the size of the PEGylated form was smaller, at 28 nm. The entrapment efficiency (EE% of PK-L4 in SLNs with and without PEG showed a high capacity of approximately 100% encapsulation. Results also showed that the amount of PK-L4 released over a prolonged period from SLNs both with and without PEG was comparable to the non-formulated group, with 16.48% and 30.04%, respectively, of the drug being released, which fit a zero-order equation. The half-maximal inhibitory concentration values of PK-L4-loaded SLNs with and those without PEG were significantly reduced by 45%–64% in the human lung carcinoma cell line (A549, 99% in the human breast adenocarcinoma cell line with estrogen receptor (MCF7, and 95% in

  18. Poly(ethylene glycol) dicarboxylate/poly(ethylene oxide) hydrogel film co-crosslinked by electron beam irradiation as an anti-adhesion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Haryanto,; Singh, Deepti; Han, Sung Soo [Department of Advanced Organic Materials Engineering, Yeungnam University, Gyongbuk 712-749 (Korea, Republic of); Son, Jun Hyuk [Department of Ophthalmology, College of Medicine, Yeungnam University, Gyongbuk 712-749 (Korea, Republic of); Kim, Seong Cheol, E-mail: sckim07@ynu.ac.kr [Department of Advanced Organic Materials Engineering, Yeungnam University, Gyongbuk 712-749 (Korea, Republic of)

    2015-01-01

    The cross-linked poly(ethylene glycol) dicarboxylate (PEGDC)/poly(ethylene oxide) (PEO) and poly(ethylene glycol) dimethacrylate (PEGDMA)/(PEO) hydrogels were developed for possible biomedical applications such as an anti-adhesion barrier. Various contents of PEGDC/PEO film were irradiated using an electron beam with various beam intensities in order to obtain various degrees of crosslinked hydrogels. The optimum dose (300 kGy) and total crosslinker content of 10% were used to prepare crosslinked hydrogel films with three different compositions (10% PEGDC, 10% PEGDMA, 5% PEGDC–5% PEGDMA). Among them, 10% PEGDC hydrogel film exhibited the highest elongation at break (69.33 ± 6.87%) with high mechanical strength. 10% PEGDC hydrogel film showed the lowest hemolysis activity (6.03 ± 0.01%) and the highest tissue adherence (75.67 ± 1.15 cN). The result also indicated that the carboxyl groups in PEGDC affect the tissue adherence of hydrogel films via H-bonding interactions. In animal studies, 10% PEGDC anti-adhesion hydrogel film degraded within 3 weeks and demonstrated better anti-adhesive effect compared to Guardix-SG®. - Highlights: • The crosslinked PEGDC/PEO hydrogel was developed by e-beam irradiation. • 10% PEGDC hydrogel film showed the highest elongation at break and tissue adhesion. • The COOH group enhanced the tissue adherence of hydrogel films on the intestine. • 10% PEGDC hydrogel film demonstrated a good anti-adhesive effect in animal study. • All of the hydrogel films with 10% PEGDC degraded in vivo within three weeks.

  19. Simultaneous small-angle neutron scattering and Fourier transform infrared spectroscopic measurements on cocrystals of syndiotactic polystyrene with polyethylene glycol dimethyl ethers1

    Science.gov (United States)

    Kaneko, Fumitoshi; Seto, Naoki; Sato, Shuma; Radulescu, Aurel; Schiavone, Maria Maddalena; Allgaier, Jürgen; Ute, Koichi

    2016-01-01

    Syndiotactic polystyrene (sPS) is a crystalline polymer which has a unique property; it is able to form cocrystals with a wide range of chemical compounds, in which the guest molecules are confined in the vacancies of the host sPS crystalline region. Recently, it has been found that even polyethylene glycol oligomers with a molecular weight of more than several hundreds can be introduced into the sPS crystalline region. It is quite important to know how such a long-chain molecule is stored in the host sPS lattice. To tackle this issue, a new simultaneous measurement method combing small-angle neutron scattering and Fourier transform infrared spectroscopy (SANS/FTIR), which has been recently developed by the authors, was applied to an sPS cocrystal with polyethylene glycol dimethyl ether with a molecular weight of 500 (PEGDME500). The temperature-dependent changes of the SANS profile and FTIR spectrum were followed from room temperature up to 413 K for a one-dimensionally oriented SANS/PEGDME500 cocrystal sample. The intensity of the reflections due to the stacking of crystalline lamellae showed a significant temperature dependence. The two-dimensional pattern in the high Q region of SANS also changed depending on temperature. The combined information obtained by SANS and FTIR suggested that PEGDME500 molecules are distributed in both the crystalline and amorphous regions in the low-temperature region close to room temperature, but they are predominantly included in the amorphous region in the high-temperature region. It was also suggested by the two-dimensional SANS profile that PEGDME500 molecules in the crystalline region have an elongated structure along the thickness direction of the crystalline lamellae. PMID:27738412

  20. Poly(ethylene glycol-cholesterol inhibits L-type Ca2+ channel currents and augments voltage-dependent inactivation in A7r5 cells.

    Directory of Open Access Journals (Sweden)

    Rikuo Ochi

    Full Text Available Cholesterol distributes at a high density in the membrane lipid raft and modulates ion channel currents. Poly(ethylene glycol cholesteryl ether (PEG-cholesterol is a nonionic amphipathic lipid consisting of lipophilic cholesterol and covalently bound hydrophilic PEG. PEG-cholesterol is used to formulate lipoplexes to transfect cultured cells, and liposomes for encapsulated drug delivery. PEG-cholesterol is dissolved in the external leaflet of the lipid bilayer, and expands it to flatten the caveolae and widen the gap between the two leaflets. We studied the effect of PEG-cholesterol on whole cell L-type Ca(2+ channel currents (I(Ca,L recorded from cultured A7r5 arterial smooth muscle cells. The pretreatment of cells with PEG-cholesterol decreased the density of ICa,L and augmented the voltage-dependent inactivation with acceleration of time course of inactivation and negative shift of steady-state inactivation curve. Methyl-β-cyclodextrin (MβCD is a cholesterol-binding oligosaccharide. The enrichment of cholesterol by the MβCD:cholesterol complex (cholesterol (MβCD caused inhibition of I(Ca,L but did not augment voltage-dependent inactivation. Incubation with MβCD increased I(Ca,L, slowed the time course of inactivation and shifted the inactivation curve to a positive direction. Additional pretreatment by a high concentration of MβCD of the cells initially pretreated with PEG-cholesterol, increased I(Ca,L to a greater level than the control, and removed the augmented voltage-dependent inactivation. Due to the enhancement of the voltage-dependent inactivation, PEG-cholesterol inhibited window I(Ca,L more strongly as compared with cholesterol (MβCD. Poly(ethylene glycol conferred to cholesterol the efficacy to induce sustained augmentation of voltage-dependent inactivation of I(Ca,L.