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Sample records for glycol unrefined polyethylene

  1. Polyethylene Glycol 3350

    MedlinePlus

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

  2. Polyethylene Glycol 3350

    MedlinePlus

    Polyethylene glycol 3350 comes as a powder to be mixed with a liquid and taken by mouth. It is usually taken once a day as needed for up to ... to produce a bowel movement.To use the powder, follow these steps: If you are using polyethylene ...

  3. Polyethylene Glycol Propionaldehydes

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  4. Osmotic effects of polyethylene glycol.

    PubMed

    Schiller, L R; Emmett, M; Santa Ana, C A; Fordtran, J S

    1988-04-01

    Polyethylene glycol (PEG) has been used to increase the osmotic pressure of fluids used to cleanse the gastrointestinal tract. However, little is known about its osmotic activity. To investigate this activity systematically, solutions of PEG of differing molecular weights were made and subjected to measurement of osmolality by both freezing point depression and vapor pressure osmometry. Measured osmolality was increasingly greater than predicted from average molecular weight as PEG concentration increased. Measurement of sodium activity in NaCl/PEG solutions by means of an ion-selective electrode suggested that the higher than expected osmolality could be due in part to interactions that, in effect, sequestered water from the solution. Osmolality was consistently greater by freezing point osmometry than by vapor pressure osmometry. To determine which osmometry method reflected biologically relevant osmolality, normal subjects underwent steady-state total gut perfusion with an electrolyte solution containing 105 g/L of PEG 3350. This produced rectal effluent that was hypertonic by freezing point osmometry but isotonic by vapor pressure osmometry. Assuming that luminal fluid reaches osmotic equilibrium with plasma during total gut perfusion, this result suggests that the vapor pressure osmometer accurately reflects the biologically relevant osmolality of intestinal contents. We conclude that PEG exerts more of an osmotic effect than would be predicted from its molecular weight. This phenomenon may reflect interactions between PEG and water molecules that alter the physical chemistry of the solution and sequester water from the solution. PMID:3345895

  5. Polyethylene glycol enhanced protein refolding.

    PubMed

    Cleland, J L; Builder, S E; Swartz, J R; Winkler, M; Chang, J Y; Wang, D I

    1992-09-01

    Previous studies on the refolding of recombinant bovine carbonic anhydrase B (CAB) indicated that polyethylene glycol (PEG) significantly enhanced the recovery of active protein by reducing aggregation. To further test the ability of PEG to enhance refolding, three recombinant human proteins, deoxyribonuclease (rhDNAse), tissue plasminogen activator (rhtPA), and interferon-gamma (rhIFN-gamma) were refolded in the presence of PEG (3350 MW). rhDNAse produced from CHO cells was denatured in 7.2 M urea and refolded by rapid dilution to 4.0 M urea and 0.20 mg/ml protein. When a final PEG to rhDNAse molar ratio of 5 to 1 (0.1 milligram PEG, 3350 MW) was used in the dilution buffer, refolding was improved by 30% to yield complete recovery of active protein. Impure E. coli derived inclusion body preparations of rhDNAse were solubilized in 8 M urea and refolded by dilution to 4 M urea and 0.10 mg/ml protein. Refolding with a dilution buffer which yielded a final PEG to rhDNAse molar ratio of 10 to 1 (0.1 milligram PEG, 3350 MW) resulted in a three-fold increase in the recovery of active protein. When PEG was used in the dilution buffer, aggregation of rhDNAse did not occur during refolding in either case. rhtPA produced from CHO cells was denatured in 5 M guanidine hydrochloride (GuHCl) and refolded by rapid dilution to 0.10 M GuHCl and 0.20 mg/ml protein.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1368998

  6. Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms

    PubMed Central

    Nalawade, Triveni Mohan; Bhat, Kishore; Sogi, Suma H. P.

    2015-01-01

    Aim: The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro. Materials and Methods: Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study. Results: All vehicles

  7. Polymeric compositions incorporating polyethylene glycol as a phase change material

    DOEpatents

    Salyer, Ival O.; Griffen, Charles W.

    1989-01-01

    A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

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

    MedlinePlus

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

  9. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  10. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene glycol (400) monolaurate. 178.3760 Section 178.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400)...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  12. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  13. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  14. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  15. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  16. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  18. Radioprotection by polyethylene glycol-protein complexes in mice

    SciTech Connect

    Gray, B.H.; Stull, R.W.

    1983-03-01

    Polyethylene glycol of about 5000 D was activated with cyanuric chloride, and the activated compound was complexed to each of three proteins. Polyethylene glycol-superoxide dismutase and polyethylene glycol-catalase were each radioprotectants when administered prophylactically to female B6CBF1 mice before irradiation. The dose reduction factor for these mice was 1.2 when 5000 units of polyethylene glycol-catalase was administered before /sup 60/Co irradiation. Female B6CBF1 mice administered prophylactic intravenous injections of catalase, polyethylene glycol-albumin, or heat-denatured polyethylene glycol-catalase had survival rates similar to phosphate-buffered saline-injected control mice following /sup 60/Co irradiation. Polyethylene glycol-superoxide dismutase and polyethylene glycol-catalase have radioprotective activity in B6CBF1 mice, which appears to depend in part on enzymatic activities of the complex. However, no radioprotective effect was observed in male C57BL/6 mice injected with each polyethylene glycol-protein complex at either 3 or 24 hr before irradiation. The mechanism for radioprotection by these complexes may depend in part on other factors.

  19. Characterization of Polyethylene Glycol Modified Hemoglobins

    NASA Astrophysics Data System (ADS)

    Salazar, Gil; Barr, James; Morgan, Wayne; Ma, Li

    2011-03-01

    Polyethylene glycol modified hemoglobins (PEGHbs) was characterized by liquid chromatography and fluorescence methods. We prepared four samples of two different molecular weight PEG, 5KDa and 20KDa, modified bovine and human hemoglobin. We studied the oxygen affinities, stabilities, and peroxidase activities of PEGHbs. We have related oxygen affinities with different degrees of modifications. The data showed that the modification on the beta subunits was less stable than that of the alpha subunits on the human Hb based samples especially. We also compared peroxidase activities among different modified PEGHbs.

  20. Water potential of aqueous polyethylene glycol.

    PubMed

    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

  1. Urinary excretion of polyethylene glycol 3350 and sulfate after gut lavage with a polyethylene glycol electrolyte lavage solution.

    PubMed

    Brady, C E; DiPalma, J A; Morawski, S G; Santa Ana, C A; Fordtran, J S

    1986-06-01

    Ingestion of an electrolyte lavage solution containing polyethylene glycol 3350 and sulfate is an effective method of cleansing the colon for diagnostic studies. Polyethylene glycol and sulfate are considered poorly absorbed from the gastrointestinal tract. Because of the quantities administered, concern exists about potential toxicity of absorption of even a small percentage, particularly for polyethylene glycol. We measured the urinary excretion of both polyethylene glycol and sulfate in normal subjects and inflammatory bowel patients. Absorption of polyethylene glycol can be assessed by measuring recovery in urine, as 85%-96% of an intravenous load is excreted in urine. Similarly, appreciable sulfate absorption would exceed renal tubular reabsorption and result in increased urinary excretion. Mean percent polyethylene glycol load recovered in urine was minimal and similar for normal (0.06%) and inflammatory bowel (0.09%) subjects. Urinary sulfate excretion after lavage was also similar for both groups and was not different from baseline. These results do not suggest the likelihood of toxicity due to polyethylene glycol 3350 or sulfate absorption during gut lavage with this solution. PMID:3699408

  2. Redox-labelled poly(ethylene glycol) used as a diffusion probe in poly(ethylene glycol) melts

    SciTech Connect

    Haas, O.; Velasquez, C.; Porat, Z.

    1995-12-01

    Ferrocene labelled monomethyl poly(ethylene glycol) MPEG with molecular weights of 1900 and 750 was prepared and used as an electrochemical diffusion probe in poly(ethylene glycol) melts. Cyclic voltammetry and chronoamperometry were used in connection with microdisk electrodes to measure the diffusion coefficient of redox tagged molecules using melted poly(ethylene glycol) as a solvent. The molecular weight of the solvent polymer was 750, 2000 and 20000. Results from the temperature dependency of the diffusion process and of the viscosity and conductivity of the polymer electrolyte are presented and discussed.

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  4. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  5. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  6. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  7. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2006-03-01

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

  9. Activation of Cytosolic Pyruvate Kinase by Polyethylene Glycol.

    PubMed Central

    Podesta, F. E.; Plaxton, W. C.

    1993-01-01

    Homogeneous cytosolic pyruvate kinase from endosperm of germinating castor oil (Ricinus communis L. cv Hale) seeds was potently activated by polyethylene glycol. The addition of 5% (w/v) polyethylene glycol to the pyruvate kinase reaction mixture caused a 2.6-fold increase in maximal velocity and 12.5- and 2-fold reductions in Km values for phosphoenolpyruvate and ADP, respectively. Glycerol, ethylene glycol, and bovine serum albumin also enhanced pyruvate kinase activity, albeit to a lesser extent than polyethylene glycol. The addition of 5% (w/v) polyethylene glycol to the elution buffer during high-performance gel filtration chromatography of purified cytosolic pyruvate kinase helped to stabilize the active heterotetrameric native structure of the enzyme. A higher degree of inhibition by MgATP, but lower sensitivity to the inhibitors 3-phosphoglycerate and fructose- 1,6-bisphosphate, was also observed in the presence of 5% (w/v) polyethylene glycol. It is concluded that (a) plant cytosolic pyruvate kinase activity and regulation, like that of other regulatory pyruvate kinases, is modified by extreme dilution in the assay medium, probably as a result of deaggregation of the native tetrameric enzyme, and (b) ATP is probably the major metabolic effector of germinating castor endosperm cytosolic pyruvate kinase in vivo. PMID:12231936

  10. Activation of Cytosolic Pyruvate Kinase by Polyethylene Glycol.

    PubMed

    Podesta, F. E.; Plaxton, W. C.

    1993-09-01

    Homogeneous cytosolic pyruvate kinase from endosperm of germinating castor oil (Ricinus communis L. cv Hale) seeds was potently activated by polyethylene glycol. The addition of 5% (w/v) polyethylene glycol to the pyruvate kinase reaction mixture caused a 2.6-fold increase in maximal velocity and 12.5- and 2-fold reductions in Km values for phosphoenolpyruvate and ADP, respectively. Glycerol, ethylene glycol, and bovine serum albumin also enhanced pyruvate kinase activity, albeit to a lesser extent than polyethylene glycol. The addition of 5% (w/v) polyethylene glycol to the elution buffer during high-performance gel filtration chromatography of purified cytosolic pyruvate kinase helped to stabilize the active heterotetrameric native structure of the enzyme. A higher degree of inhibition by MgATP, but lower sensitivity to the inhibitors 3-phosphoglycerate and fructose- 1,6-bisphosphate, was also observed in the presence of 5% (w/v) polyethylene glycol. It is concluded that (a) plant cytosolic pyruvate kinase activity and regulation, like that of other regulatory pyruvate kinases, is modified by extreme dilution in the assay medium, probably as a result of deaggregation of the native tetrameric enzyme, and (b) ATP is probably the major metabolic effector of germinating castor endosperm cytosolic pyruvate kinase in vivo. PMID:12231936

  11. Hydration of polyethylene glycol-grafted liposomes.

    PubMed

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

    1998-03-01

    This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG2000 binds 136 +/- 4 molecules of water. For PEG2000 covalently attached to the lipid molecules organized in micelles, the water binding increases to 210 +/- 6 water molecules. This demonstrates that the two different structural configurations of the PEG2000, a random coil in the case of the free PEG and a brush in the case of DHP-PEG2000 micelles, differ in their hydration level. Ultrasound absorption changes in liposomes reflect mainly the heterophase fluctuations and packing defects in the lipid bilayer. The PEG-induced excess ultrasound absorption of the lipid bilayer at 7.7 MHz for PEG-lipid concentrations over 5 mol % indicates the increase in the relaxation time of the headgroup rotation due to PEG-PEG interactions. The adiabatic compressibility (calculated from ultrasound velocity and density) of the lipid bilayer of the liposome increases monotonically with PEG-lipid concentration up to approximately 7 mol %, reflecting release of water from the lipid headgroup region. Elimination of this water, induced by grafted PEG, leads to a decrease in bilayer defects and enhanced lateral packing of the phospholipid acyl chains. We assume that the dehydration of the lipid headgroup region in conjunction with the increase of the hydration of the outer layer by grafting PEG in brush configuration are responsible for increasing thermodynamic stability of the liposomes at 5-7 mol % of PEG-lipid. At higher PEG-lipid concentrations, compressibility and partial volume of the lipid phase

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

    PubMed

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

    2008-04-01

    In acute lung injuries, inactivating agents may interfere with transfer (adsorption) of pulmonary surfactants to the interface between air and the aqueous layer that coats the interior of alveoli. Some ionic and nonionic polymers reduce surfactant inactivation in vitro and in vivo. In this study, we tested directly whether an ionic polymer, hyaluronan, or a nonionic polymer, polyethylene glycol, enhanced adsorption of a surfactant used clinically. We used three different methods of measuring adsorption in vitro: a modified pulsating bubble surfactometer; a King/Clements device; and a spreading trough. In addition we measured the effects of both polymers on surfactant turbidity, using this assay as a nonspecific index of aggregation. We found that both hyaluronan and polyethylene glycol significantly increased the rate and degree of surfactant material adsorbed to the surface in all three assays. Hyaluronan was effective in lower concentrations (20-fold) than polyethylene glycol and, unlike polyethylene glycol, hyaluronan did not increase apparent aggregation of surfactant. Surfactant adsorption in the presence of serum was also enhanced by both polymers regardless of whether hyaluronan or polyethylene glycol was included with serum in the subphase or added to the surfactant applied to the surface. Therefore, endogenous polymers in the alveolar subphase, or exogenous polymers added to surfactant used as therapy, may both be important for reducing inactivation of surfactant that occurs with various lung injuries. PMID:18065212

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

    NASA Astrophysics Data System (ADS)

    Brullot, W.; Reddy, N. K.; Wouters, J.; Valev, V. K.; Goderis, B.; Vermant, J.; Verbiest, T.

    2012-06-01

    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.

  14. Molecularly uniform poly(ethylene glycol) certified reference material

    NASA Astrophysics Data System (ADS)

    Takahashi, Kayori; Matsuyama, Shigetomo; Kinugasa, Shinichi; Ehara, Kensei; Sakurai, Hiromu; Horikawa, Yoshiteru; Kitazawa, Hideaki; Bounoshita, Masao

    2015-02-01

    A certified reference material (CRM) for poly(ethylene glycol) with no distribution in the degree of polymerization was developed. The degree of polymerization of the CRM was accurately determined to be 23. Supercritical fluid chromatography (SFC) was used to separate the molecularly uniform polymer from a standard commercial sample with wide polydispersity in its degree of polymerization. Through the use of a specific fractionation system coupled with SFC, we are able to obtain samples of poly(ethylene glycol) oligomer with exact degrees of polymerization, as required for a CRM produced by the National Metrology Institute of Japan.

  15. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  16. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  17. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  18. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  19. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  20. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ethylene oxide and water with a mean molecular weight of 200 to 9,500. (2) It contains no more than 0.2... the total ethylene and diethylene glycol content of polyethylene glycols having mean molecular weights... and diethylene glycol content of polyethylene glycols having mean molecular weights below...

  1. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ethylene oxide and water with a mean molecular weight of 200 to 9,500. (2) It contains no more than 0.2... the total ethylene and diethylene glycol content of polyethylene glycols having mean molecular weights... and diethylene glycol content of polyethylene glycols having mean molecular weights below...

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

    PubMed Central

    Boles, Erin E.; Gaines, Cameryn L.

    2015-01-01

    OBJECTIVES: The objective of this study was to evaluate the safety and efficacy of polyethylene glycol-electrolyte solution vs polyethylene glycol-3350 for the treatment of fecal impaction in pediatric patients. METHODS: A retrospective, observational, institutional review board–approved study was conducted over a 1-year time period. Patients were included in the study if they were admitted to the hospital with a diagnosis of fecal impaction or constipation and were treated with either polyethylene glycol-electrolyte solution (PEG-ES) or polyethylene glycol-3350 (PEG-3350). Patients were excluded if they were discharged prior to resolution of treatment and/or did not receive PEG-ES or PEG-3350. RESULTS: Fifty-one patients (ranging in age from 1 month to 15 years) were evaluated: 23 patients received PEG-ES and 28 patients received PEG-3350. Sex, race, age, and weight were not statistically different between the 2 groups. Resolution of fecal impaction was not significantly different between PEG-ES vs PEG-3350 (87% and 86%, respectively; p = 0.87). There was only 1 reported side effect with PEG-3350, vs 11 reported side effects with PEG-ES (p < 0.01). CONCLUSIONS: Theses results suggest that PEG-3350 is as effective as PEG-ES for the treatment of fecal impaction in pediatric patients and is associated with fewer side effects. PMID:26170773

  3. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene glycol (mean molecular weight 200-9... Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene... chapter. (c) The provisions of paragraph (b) of this section are not applicable to polyethylene...

  4. Polyethylene Glycol (PEG)-Induced Anaphylactic Reaction During Bowel Preparation

    PubMed Central

    2015-01-01

    Barium enema is used to screen patients with gastrointestinal bleeding who do not want to undergo colonoscopy. Polyethylene glycol (PEG) is usually the bowel preparation of choice. Few allergic reactions from this product have been reported; these include urticaria, angioedema, and anaphylaxis. Reactions are thought to result from a small amount of PEG crossing the intestinal mucosa, which, in some patients, is sufficient to provoke an anaphylactic reaction. PMID:26203443

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  6. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  7. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  8. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  9. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid (H3BO3), mixed esters with... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol... NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.1729...

  10. Cementitious building material incorporating end-capped polyethylene glycol as a phase change material

    DOEpatents

    Salyer, Ival O.; Griffen, Charles W.

    1986-01-01

    A cementitious composition comprising a cementitious material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the compositions are useful in making pre-formed building materials such as concrete blocks, brick, dry wall and the like or in making poured structures such as walls or floor pads; the glycols can be encapsulated to reduce their tendency to retard set.

  11. Electrochemical measurements of diffusion coefficients of redox-labeled poly(ethylene glycol) dissolved in poly(ethylene glycol) melts

    SciTech Connect

    Haas, O.; Velazquez, C.S.; Porat, Z.; Murray, R.W.

    1995-10-12

    Ferrocene labeled monomethoxy-poly(ethylene glycol)s (MPEG) with molecular weights of 1900 and 750 were used as redox probe solutes in poly(ethylene glycol) melt solvents of molecular weight 750, 2000, and 20000. Cyclic voltammetry and chronoamperometry at microdisk electrodes were employed to measure the diffusion coefficients of the redox probes, which were independent of the probe concentration and varied between 10{sup -7} and 10{sup -10} cm{sup 2}/s. Diffusional activation barrier results also suggest that the ferrocene label does not significantly influence the diffusivity of the probe molecule in the host solvent. Activation barrier, viscosity, and ionic conductivity results show that the LiClO{sub 4} electrolyte does not influence the diffusion barrier or viscosity as long as the ether O/Li{sup +} ratio is >=250 (ca. 0.1 M) which is still a sufficient electrolyte concentration to allow quantitative electrochemical diffusion measurements. 21 refs., 7 figs., 2 tabs.

  12. Complete Genome Sequence of Polypropylene Glycol- and Polyethylene Glycol-Degrading Sphingopyxis macrogoltabida Strain EY-1

    PubMed Central

    Nagata, Yuji; Numata, Mitsuru; Tsuchikane, Kieko; Hosoyama, Akira; Yamazoe, Atsushi; Tsuda, Masataka; Fujita, Nobuyuki; Kawai, Fusako

    2015-01-01

    Strain EY-1 was isolated from a microbial consortium growing on a random polymer of ethylene oxide and propylene oxide. Strain EY-1 grew on polyethylene glycol and polypropylene glycol and identified as Sphingopyxis macrogoltabida. Here, we report the complete genome sequence of Sphingopyxis macrogoltabida EY-1. The genome of strain EY-1 is comprised of a 4.76-Mb circular chromosome, and five plasmids. The whole finishing was conducted in silico, with aids of computational tools GenoFinisher and AceFileViewer. Strain EY-1 is available from Biological Resource Center, National Institute of Technology and Evaluation (Tokyo, Japan) (NITE). PMID:26634754

  13. Effect of tocopheryl polyethylene glycol succinate on the percutaneous penetration of minoxidil from water/ethanol/polyethylene glycol 400 solutions.

    PubMed

    Sheu, Ming-Thau; Wu, An-Bang; Lin, Keng-Ping; Shen, Chao-Hui; Ho, Hsiu-O

    2006-06-01

    We described to achieve the local retention of minoxidil which has penetrated the skin with minimization of its absorption into the general circulation and elimination of local irritation induced by propylene glycol. The effect of tocopheryl polyethylene glycol succinate (TPGS) on the penetration flux of minoxidil and its retention in the skin from topical minoxidil formulations consisting of water, alcohol, and polyethylene glycol 400 was characterized by an experimental design of ten solvent formulations in this study. Results show that the addition of TPGS was only able to improve the solubility of minoxidil in those solvent systems containing higher proportions of water and PEG 400, and the extent of improvement was also more profound with the addition of TPGS at concentrations higher than 5%. For those solvent systems containing a higher fraction of alcohol, an insignificant change in minoxidil solubility with increasing added amounts of TPGS was noted even with the tendency to decrease the solubility of minoxidil with higher amounts of TPGS. Increasing the amount of TPGS added gradually increased the flux and the corrected flux from solvent formulations with a lower solubility parameter, but decreased those from solvent systems with a higher solubility parameter. With the addition of TPGS, solvent formulation F6 (alcohol:PEG 400 of 50:50) was demonstrated to be the optimal choice by having an improved local effect and a reduced systemic effect compared to the reference of 2% Regaine((R)). Tocopheryl polyethylene glycol succinate (TPGS) was mainly retained locally in the stratum corneum, and the amount was proportional to the increase in the amount of TPGS added to these ten solvent formulations. PMID:16720414

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

    PubMed

    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

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

    PubMed

    Mbah, C J

    2007-01-01

    Sunscreen products are widely used to protect the skin from sun-related deleterious effects. The objective of the study was to investigate the potential effect of glycerol, propylene glycol and polyethylene glycol 400 on dermal absorption of oxybenzone by studying their effects on its partition coefficient. The partition coefficient was evaluated in a chloroform-water system at room temperature. It was found that glycerol and propylene glycol decreased the partition coefficient of oxybenzone, while an increase in partition coefficient was observed with polyethylene glycol 400. The findings suggest that polyethylene glycol 400 in contrast to glycerol and propylene glycol has the potential of increasing the vehicle-skin partition coefficient of oxybenzone when cosmetic products containing such an UV absorber are topically applied to the skin. PMID:17294811

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

    PubMed

    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

  17. Polyethylene glycol-based homologated ligands for nicotinic acetylcholine receptors☆

    PubMed Central

    Scates, Bradley A.; Lashbrook, Bethany L.; Chastain, Benjamin C.; Tominaga, Kaoru; Elliott, Brandon T.; Theising, Nicholas J.; Baker, Thomas A.; Fitch, Richard W.

    2010-01-01

    A homologous series of polyethylene glycol (PEG) monomethyl ethers were conjugated with three ligand series for nicotinic acetylcholine receptors. Conjugates of acetylaminocholine, the cyclic analog 1-acetyl-4,4-dimethylpiperazinium, and pyridyl ether A-84543 were prepared. Each series was found to retain significant affinity at nicotinic receptors in rat cerebral cortex with tethers of up to six PEG units. Such compounds are hydrophilic ligands which may serve as models for fluorescent/affinity probes and multivalent ligands for nAChR. PMID:19006672

  18. Particle Size Control of Polyethylene Glycol Coated Fe Nanoparticles

    NASA Astrophysics Data System (ADS)

    Srinivasan, B.; Bonder, M. J.; Zhang, Y.; Gallo, D.; Hadjipanayis, G. C.

    2006-03-01

    Recent interest in Fe nanoparticles with high magnetization is driven by their potential use in biomedical applications such as targeted drug delivery, MRI contrast enhancement and hyperthermia treatment of cancer. This study looks at the use of a polyethylene glycol (PEG) solution to mediate the particle size and therefore control the coercivity of the resulting nanoparticles. Iron nanoparticles were synthesized using an aqueous sodium borohydride reduction of ferrous chloride by a simultaneous introduction of reagents in a Y- junction. The resulting product was collected in a vessel containing a 15 mg/ml carboxyl terminated polyethylene glycol (cPEG) in ethyl alcohol solution located under the Y junction. By varying the length of tubing below the Y junction, the particle size was varied from 5-25 nm. X-ray diffraction data indicates the presence of either amorphous Fe-B or crystalline alpha Fe, depending on the molar ratio of reagents. Magnetic measurements indicate the particles are ferromagnetic with values of coercivity ranging from 200-500 Oe and a saturation magnetization in range of 70-110 emu/g. The XRD shows that the particles are not affected by the polymer coating.

  19. Synthesis and properties of oligodeoxyribonucleotide-polyethylene glycol conjugates.

    PubMed Central

    Jäschke, A; Fürste, J P; Nordhoff, E; Hillenkamp, F; Cech, D; Erdmann, V A

    1994-01-01

    Pools of oligonucleotide conjugates consisting of 10-400 different molecular species were synthesized. The conjugates contained a varying number of ethylene glycol units attached to 3'-terminal, 5'-terminal and internal positions of the oligonucleotides. Conjugate synthesis was performed by phosphoramidite solid phase chemistry using suitably protected polyethylene glycol phosphoramidites and PEG-derivatized solid supports containing polydisperse PEGs of various molecular weight ranges. The pools were analyzed and fractionated by chromatographic and electrophoretic techniques, and the composition of isolated conjugates was revealed by matrix-assisted laser desorption/ionization mass spectrometry. The number and attachment sites of coupled ethylene glycol units greatly influence the hydrophobicity of the conjugates, as well as their electrophoretic mobilities. Conjugation had little effect on the hybridization behavior of oligonucleotide conjugates with unmodified complementary oligonucleotide strands. Melting temperatures were between 67 and 73 degrees C, depending on the size and number of coupled PEG chains, compared to 68 degrees C for the unmodified duplex. Conjugates with PEG coupled to both 3'- and 5'-terminal positions showed a more than 10-fold increase in exonuclease stability. PMID:7984434

  20. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... sulfate salt (generic). 721.10546 Section 721.10546 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt... identified generically as pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject...

  1. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... sulfate salt (generic). 721.10546 Section 721.10546 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt... identified generically as pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject...

  2. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  3. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  4. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9... molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as a... conditions: (a) The additive is an addition polymer of ethylene oxide and water with a mean molecular...

  5. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9... molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as a... conditions: (a) The additive is an addition polymer of ethylene oxide and water with a mean molecular...

  6. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  7. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  8. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  9. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  10. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., potassium salt. 721.3900 Section 721.3900 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  11. The effect of polyethylene glycol on shellac stability

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

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

    SciTech Connect

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

    2014-03-28

    We report on the mechanism of membrane fusion mediated by polyethylene glycol (PEG) and Ca{sup 2+} by means of a coarse-grained molecular dynamics simulation approach. Our data provide a detailed view on the role of cations and polymer in modulating the interaction between negatively charged apposed membranes. The PEG chains cause a reduction of the inter-lamellar distance and cause an increase in concentration of divalent cations. When thermally driven fluctuations bring the membranes at close contact, a switch from cis to trans Ca{sup 2+}-lipid complexes stabilizes a focal contact acting as a nucleation site for further expansion of the adhesion region. Flipping of lipid tails induces subsequent stalk formation. Together, our results provide a molecular explanation for the synergistic effect of Ca{sup 2+} and PEG on membrane fusion.

  13. Horseradish Peroxidase Inactivation: Heme Destruction and Influence of Polyethylene Glycol

    PubMed Central

    Mao, Liang; Luo, Siqiang; Huang, Qingguo; Lu, Junhe

    2013-01-01

    Horseradish peroxidase (HRP) mediates efficient conversion of many phenolic contaminants and thus has potential applications for pollution control. Such potentially important applications suffer however from the fact that the enzyme becomes quickly inactivated during phenol oxidation and polymerization. The work here provides the first experimental data of heme consumption and iron releases to support the hypothesis that HRP is inactivated by heme destruction. Product of heme destruction is identified using liquid chromatography with mass spectrometry. The heme macrocycle destruction involving deprivation of the heme iron and oxidation of the 4-vinyl group in heme occurs as a result of the reaction. We also demonstrated that heme consumption and iron releases resulting from HRP destruction are largely reduced in the presence of polyethylene glycol (PEG), providing the first evidence to indicate that heme destruction is effectively suppressed by co-dissolved PEG. These findings advance a better understanding of the mechanisms of HRP inactivation. PMID:24185130

  14. Polyethylene glycol diffusion in ex vivo skin tissue

    NASA Astrophysics Data System (ADS)

    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.

  15. Effects of sterilization on poly(ethylene glycol) hydrogels.

    PubMed

    Kanjickal, Deenu; Lopina, Stephanie; Evancho-Chapman, M Michelle; Schmidt, Steven; Donovan, Duane

    2008-12-01

    The past few decades have witnessed a dramatic increase in the development of polymeric biomaterials. These biomaterials have to undergo a sterilization procedure before implantation. However, many sterilization procedures have been shown to profoundly affect polymer properties. Poly(ethylene glycol) hydrogels have gained increasing importance in the controlled delivery of therapeutics and in tissue engineering. We evaluated the effect of ethylene oxide (EtO), hydrogen peroxide (H(2)O(2)), and gamma sterilization of poly(ethylene glycol) hydrogels on properties relevant to controlled drug delivery and tissue engineering. We observed that the release of cyclosporine (CyA) (an immunosuppressive drug that is effective in combating tissue rejection following organ transplantation) was significantly affected by the type of sterilization. However, that was not the case with rhodamine B, a dye. Hence, the drug release characteristics were observed to be dependent not only on the sterilization procedure but also on the type of agent that needs to be delivered. In addition, differences in the swelling ratios for the sterilized and unsterilized hydrogels were statistically significant for 1:1 crosslinked hydrogels derived from the 8000 MW polymer. Significant differences were also observed for gamma sterilization for 1:1 crosslinked hydrogels derived from the 3350 MW polymer and also the 2:1 crosslinked hydrogels derived from the 8000 MW polymer. Atomic force microscopy (AFM) studies revealed that the roughness parameter for the unsterilized and EtO-sterilized PEG hydrogels remained similar. However, a statistically significant reduction of the roughness parameter was observed for the H(2)O(2) and gamma-sterilized samples. Electron spin resonance (ESR) studies on the unsterilized and the sterilized samples revealed the presence of the peroxy and the triphenyl methyl carbon radical in the samples. The gamma and the H(2)O(2)-sterilized samples were observed to have a much

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

    PubMed

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

    2001-09-01

    The fabrication of hydrogel microstructures based upon poly(ethylene glycol) diacrylates, dimethacrylates, and tetraacrylates patterned photolithographically on silicon or glass substrates is described. A silicon/silicon dioxide surface was treated with 3-(trichlorosilyl)propyl methacrylate to form a self-assembled monolayer (SAM) with pendant acrylate groups. The SAM presence on the surface was verified using ellipsometry and time-of-flight secondary ion mass spectrometry. A solution containing an acrylated or methacrylated poly(ethylene glycol) derivative and a photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was spin-coated onto the treated substrate, exposed to 365 nm ultraviolet light through a photomask, and developed with either toluene, water, or supercritical CO2. As a result of this process, three-dimensional, cross-linked PEG hydrogel microstructures were immobilized on the surface. Diameters of cylindrical array members were varied from 600 to 7 micrometers by the use of different photomasks, while height varied from 3 to 12 micrometers, depending on the molecular weight of the PEG macromer. In the case of 7 micrometers diameter elements, as many as 400 elements were reproducibly generated in a 1 mm2 square pattern. The resultant hydrogel patterns were hydrated for as long as 3 weeks without delamination from the substrate. In addition, micropatterning of different molecular weights of PEG was demonstrated. Arrays of hydrogel disks containing an immobilized protein conjugated to a pH sensitive fluorophore were also prepared. The pH sensitivity of the gel-immobilized dye was similar to that in an aqueous buffer, and no leaching of the dye-labeled protein from the hydrogel microstructure was observed over a 1 week period. Changes in fluorescence were also observed for immobilized fluorophore labeled acetylcholine esterase upon the addition of acetyl acholine. PMID:12448421

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  18. A thermosensitive hydrogel based on biodegradable amphiphilic poly(ethylene glycol) polycaprolactone poly(ethylene glycol) block copolymers

    NASA Astrophysics Data System (ADS)

    Gong, Chang Yang; Qian, Zhi Yong; Liu, Cai Bing; Juan Huang, Mei; Gu, Ying Chun; Wen, Yan Jun; Kan, Bing; Wang, Ke; Dai, Mei; Li, Xing Yi; Gou, Ma Ling; Tu, Ming Jing; Wei, Yu Quan

    2007-06-01

    A series of low molecular weight poly(ethylene glycol)-polycaprolactone-poly(ethylene glycol) (PEG-PCL-PEG) biodegradable block copolymers were successfully synthesized using isophorone diisocyanate (IPDI) as the coupling agent, and were characterized using 1H NMR and Fourier transform infrared spectroscopy. The aqueous solutions of the PEG-PCL-PEG copolymers displayed a special thermosensitive gel-sol transition when the concentration was above the corresponding critical gel concentration. Gel-sol phase diagrams were recorded using the test-tube-inversion method; they depended on the hydrophilic/hydrophobic balance in the macromolecular structure, as well as some other factors, including the heating history, volume, and the ageing time of the copolymer aqueous solutions and dissolution temperature of the copolymers. As a result, the gel-sol transition temperature range could be altered, which might be very useful for application in injectable drug delivery systems. This work was financially supported by the Chinese Key Basic Research Program (2004CB518800 and 2004CB518807), and the Sichuan Key Project of Science and Technology (06(05SG022-021-02)).

  19. Hemoglobin precipitation by polyethylene glycols leads to underestimation of membrane pore sizes.

    PubMed

    Quijano, Jairo C; Lemeshko, Victor V

    2008-12-01

    The size of pores formed in the plasma membrane by various substances is frequently determined using polyethylene glycols as osmotic protectants. In this work, we have found that the size of pores formed by saponin in the red blood cell membrane determined by hemolysis versus molecular weight of polyethylene glycol was different to that estimated by light dispersion of cell suspensions. After complete swelling of cells induced by saponin in semiisotonic salt media containing 150 mOsm PEG-4000 or PEG-3000, a significant increase in the light absorbance at 640 nm was developed resulting from the formation of hemoglobin precipitates. Easily sedimenting aggregates were also formed when the supernatant of lysed cells was added to the equiosmotic solutions of polyethylene glycols with molecular weight higher than 1000. We suggest that the real size of large pores could be underestimated due to the phenomenon of hemoglobin precipitation by polyethylene glycols. PMID:18692020

  20. Partitioning of differently sized poly(ethylene glycol)s into OmpF porin.

    PubMed Central

    Rostovtseva, Tatiana K; Nestorovich, Ekaterina M; Bezrukov, Sergey M

    2002-01-01

    To understand the physics of polymer equilibrium and dynamics in the confines of ion channel pores, we study partitioning of poly(ethylene glycol)s (PEGs) of different molecular weights into the bacterial porin, OmpF. Thermodynamic and kinetic parameters of partitioning are deduced from the effects of polymer addition on ion currents through single OmpF channels reconstituted into planar lipid bilayer membranes. The equilibrium partition coefficient is inferred from the average reduction of channel conductance in the presence of PEG; rates of polymer exchange between the pore and the bulk are estimated from PEG-induced conductance noise. Partition coefficient as a function of polymer weight is best fitted by a "compressed exponential" with the compression factor of 1.65. This finding demonstrates that PEG partitioning into the OmpF channel pore has sharper dependence on polymer molecular weight than predictions of hard-sphere, random-flight, or scaling models. A 1360-Da polymer separates regimes of partitioning and exclusion. Comparison of its characteristic size with the size of a 2200-Da polymer previously found to separate these regimes for the alpha-toxin shows good agreement with the x-ray structural data for these channels. The PEG-induced conductance noise is compatible with the polymer mobility reduced inside the OmpF pore by an order of magnitude relatively to its value in bulk solution. PMID:11751305

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

    PubMed

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

    2008-05-01

    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 the pallet array geometry and the properties of the overlying solution. Even though surrounded with PEG walls, the individual pallets were detached from the array by the mechanical force generated by a focused laser pulse, with a release threshold of 6 microJ. Since the PEG hydrogels are repellent to protein adsorption and cell attachment, the walls localized cell growth to the pallet top surface. Cells grown in the microwells formed by the PEG walls were released by detaching the underlying pallet. The released cells/pallets were collected, cultured and clonally expanded. The micropallet arrays with PEG walls provide a platform for performing single cell analysis and sorting on chip. PMID:18432343

  2. Optical clearing of skin tissue ex vivo with polyethylene glycol

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    Alterations of the optical and structural (weight, thickness, and square) parameters of skin caused by polyethylene glycol (PEG) with molecular weights of 300 and 400 Da were studied experimentally. The objects of the study were ex vivo skin samples of albino laboratory rats. Collimated transmittance of the skin was measured in the wavelength range 500-900 nm. As a result of exposure to the agents, an increase in the collimated transmittance and a decrease in weight, thickness, and square of skin samples were observed. Analysis of the kinetics of parameters alterations allowed us to measure the diffusion coefficient of the agents in the skin as (1.83 ± 2.22) × 10-6 and (1.70 ± 1.47) × 10-6 cm2/s for PEG-300 and PEG-400, respectively, and the rate of alterations of the structural parameters. The results obtained in this study can be used for the improvement of existing and development of new methods of noninvasive diagnostics and therapy of subcutaneous diseases.

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

    PubMed

    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

  4. Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use

    PubMed Central

    Shin, Chan Young; Kim, Kyu-Bong

    2015-01-01

    Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient. PMID:26191379

  5. Fluoroalkylated polyethylene glycol as potential surfactant for perfluorocarbon emulsion.

    PubMed

    Peng, C A; Hsu, Y C

    2001-11-01

    So far, perfluorocarbon (PFC) emulsions have been manufactured based mainly on two surfactants, Pluronic F-68 and egg yolk phospholipids (EYP) for clinical use. However, they have been documented to induce inflammatory or allergic responses when PFC emulsions were injected into human bloodstream. The cause of these side effects is associated with the phagocytosis of emulsified PFC microparticles by cells such as macrophages. In order to lessen the side effects, it is logic to develop surfactants, which are more phagocytosis-resistant and biocompatible. In this study, a perfluoroalkylated polyethylene glycol (R(F)-PEG) surfactant was synthesized by reacting perfluorooctanoyl chloride (C7F15COCl) with PEG of molecular weigh 8000. Both R(F)-PEG 8000 and EYP were used to make PFC emulsions separately by an ultrasonic homogenizer. Individual PFC emulsions were then incubated with mouse macrophage J774A.1 cells to examine the degree of phagocytosis. From microscopic observation of cell morphology, our results showed that the process of phagocytosis was retarded to a large extend using the R(F)-PEG surfactant. We also harnessed 19F-NMR to quantitatively detect the amount of PFC emulsions phagocytosed by J774A.1 cells. 19F-NMR result was consistent with the qualitative microscopic observation aforementioned. PMID:11795633

  6. Coarse-grained models for aqueous polyethylene glycol solutions.

    PubMed

    Choi, Eunsong; Mondal, Jagannath; Yethiraj, Arun

    2014-01-01

    A new coarse-grained force field is developed for polyethylene glycol (PEG) in water. The force field is based on the MARTINI model but with the big multipole water (BMW) model for the solvent. The polymer force field is reparameterized using the MARTINI protocol. The new force field removes the ring-like conformations seen in simulations of short chains with the MARTINI force field; these conformations are not observed in atomistic simulations. We also investigate the effect of using parameters for the end-group that are different from those for the repeat units, with the MARTINI and BMW/MARTINI models. We find that the new BMW/MARTINI force field removes the ring-like conformations seen in the MARTINI models and has more accurate predictions for the density of neat PEG. However, solvent-separated-pairs between chain ends and slow dynamics of the PEG reflect its own artifacts. We also carry out fine-grained simulations of PEG with bundled water clusters and show that the water bundling can lead to ring-like conformations of the polymer molecules. The simulations emphasize the pitfalls of coarse-graining several molecules into one site and suggest that polymer-solvent systems might be a stringent test for coarse-grained force fields. PMID:24350686

  7. Intramolecular Hydrogen Bonds in Low-Molecular-Weight Polyethylene Glycol.

    PubMed

    Kozlowska, Mariana; Goclon, Jakub; Rodziewicz, Pawel

    2016-04-18

    We used static DFT calculations to analyze, in detail, the intramolecular hydrogen bonds formed in low-molecular-weight polyethylene glycol (PEG) with two to five repeat subunits. Both red-shifted O-H⋅⋅⋅O and blue-shifting C-H⋅⋅⋅O hydrogen bonds, which control the structural flexibility of PEG, were detected. To estimate the strength of these hydrogen bonds, the quantum theory of atoms in molecules was used. Car-Parrinello molecular dynamics simulations were used to mimic the structural rearrangements and hydrogen-bond breaking/formation in the PEG molecule at 300 K. The time evolution of the H⋅⋅⋅O bond length and valence angles of the formed hydrogen bonds were fully analyzed. The characteristic hydrogen-bonding patterns of low-molecular-weight PEG were described with an estimation of their lifetime. The theoretical results obtained, in particular the presence of weak C-H⋅⋅⋅O hydrogen bonds, could serve as an explanation of the PEG structural stability in the experimental investigation. PMID:26864943

  8. Microfluidic Valves Made From Polymerized Polyethylene Glycol Diacrylate

    PubMed Central

    Rogers, Chad I.; Oxborrow, Joseph B.; Anderson, Ryan R.; Tsai, Long-Fang; Nordin, Gregory P.; Woolley, Adam T.

    2013-01-01

    Pneumatically actuated, non-elastomeric membrane valves fabricated from polymerized polyethylene glycol diacrylate (poly-PEGDA) have been characterized for temporal response, valve closure, and long-term durability. A ~100 ms valve opening time and a ~20 ms closure time offer valve operation as fast as 8 Hz with potential for further improvement. Comparison of circular and rectangular valve geometries indicates that the surface area for membrane interaction in the valve region is important for valve performance. After initial fabrication, the fluid pressure required to open a closed circular valve is ~50 kPa higher than the control pressure holding the valve closed. However, after ~1000 actuations to reconfigure polymer chains and increase elasticity in the membrane, the fluid pressure required to open a valve becomes the same as the control pressure holding the valve closed. After these initial conditioning actuations, poly-PEGDA valves show considerable robustness with no change in effective operation after 115,000 actuations. Such valves constructed from non-adsorptive poly-PEGDA could also find use as pumps, for application in small volume assays interfaced with biosensors or impedance detection, for example. PMID:24357897

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

    PubMed

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

    2016-05-20

    The separation and characterization of polyethylene glycols (PEGs) and amino-substituted derivatives on common silica-based reversed-phase packing columns using isocratic elution is described. This separation is achieved by liquid chromatography under the near critical conditions (LCCC), based on the number of amino functional end groups without obvious effect of molar mass for PEGs. The mobile phase is acetonitrile in water with an optimal ammonium acetate buffer. The separation mechanism of PEG and amino-substituted PEG under the near LCCC on silica-based packing columns is confirmed to be ion-exchange interaction. Under the LCCC of PEG backbone, with fine tune of buffer concentration, the retention factor ratios for benzylamine and phenol in buffered mobile phases, α(benzylamine/phenol)-values, were used to assess the ion-exchange capacity on silica-based reversed-phase packing columns. To the best of our knowledge, this is the first report on separation of amino-functional PEGs independent of the molar mass by isocratic elution using common C18 or phenyl reversed-phase packing columns. PMID:27102303

  10. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene...

  11. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene...

  12. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene...

  13. Interaction between water and poly(vinylpyrrolidone) containing polyethylene glycol.

    PubMed

    Hamaura, T; Newton, J M

    1999-11-01

    Information on the interaction between water and polymers is indispensable for manufacturing solid dispersion of a drug by hot-melt extrusion because this interaction affects various properties of the water-polymer mixtures, such as their viscoelastic properties. In this study, poly(vinylpyrrolidone) K30 (PVP) containing 0%, 10%, and 20% poly(ethylene glycol) 400 (PEG) was used as model amorphous polymers. The interaction of water with these polymers was assessed by the evaluation of the glass transition temperature (Tg), the point on the isotherm corresponding to the weight of sorbed water required to form a complete monolayer on the solid surface (apparent Wm), and the maximal amount of nonfreezing water, which were measured by differential scanning calorimetry and water sorption isotherms. In all of the systems with a water content below a certain water fraction (0.1 for PVP, 0.12 for PVP-PEG 10%, and 0.16 for PVP-PEG 20%), the Tg values were successfully predicted using theoretical equations, whereas the experimental Tg values were higher than predicted for those with a water content above these water fraction levels. In addition, these values of water fraction are similar to the apparent W(m) values determined using the Guggenheim-Anderson-DeBoer (GAB) equation (0.110, 0.117, and 0.147 weight fraction of water for PVP, PVP-PEG 10%, and PVP-PEG 20%, respectively). Nonfreezing water is detected above 0.47, 0.49, and 0.51 weight fraction of water for PVP, PVP-PEG 10%, and PVP-PEG 20%, respectively. Miscibility between water and PVP or PVP-PEG seems to change according to the water content in the system. All parameters increase with the concentration of PEG in the sample. This may be explained by the fact that PEG has a larger number of polymer repeating units, which may therefore interact with water more than PVP. PMID:10564074

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  15. Distraction induced Enterogenesis: A unique mouse model using polyethylene glycol

    PubMed Central

    Okawada, Manabu; Maria, Haytham Mustafa; Teitelbaum, Daniel H.

    2011-01-01

    Background/Purpose Recent studies have demonstrated that the small intestine can be lengthened by applying mechanical forces to the bowel lumen – distraction-induced enterogenesis. However, the mechanisms which account for this growth are unknown, and might be best examined using a mouse model. The purpose of this study is to establish the feasibility of developing distractive-induced small bowel growth in mouse. Methods 12-week old C57BL/6J mice had a jejunal segment taken out of continuity, and distended with polyethylene glycol (PEG: 3350 KDa); this group was compared to a control group without stretching. Segment length and diameter were measured intra-operatively and after 5 days. Villus height, crypt depth, muscle thickness in the isolated segment were assessed. Rate of epithelial cell proliferation (5-bromo-2-deoxyuridine: BrdU incorporation) in crypt was also examined. The mucosal mRNA expression of targeted factors were performed to investigate potential mechanisms of which might lead to distraction-induced enterogenesis. Results At harvest, the PEG-stretch group showed a significant increase in length and diameter versus controls. Villus height, crypt depth and muscular layer thickness increased in the PEG group. The PEG group also showed significantly increased rates of epithelial cell proliferation versus controls. Real-time PCR showed a trend toward higher β-catenin and c-myc mRNA expression in the PEG stretched group; however, this difference was not statistically significant. Conclusions Radial distraction-induced enterogenesis with PEG is a viable method for increasing small intestinal length and diameter. This model may provide a new method for studying the mechanisms leading to distraction-induced enterogenesis. PMID:21605872

  16. A course-grained model for polyethylene glycol polymer

    SciTech Connect

    Nicholson, Don M; Wang, Qifei; Keffer, David J

    2011-01-01

    A coarse-grained (CG) model of polyethylene glycol (PEG) was developed and implemented in CG molecular dynamics (MD) simulations of PEG chains with degree of polymerization (DP) 20 and 40. In the model, two repeat units of PEG are grouped as one CG bead. Atomistic MD simulation of PEG chains with DP = 20 was first conducted to obtain the bonded structural probability distribution functions (PDFs) and nonbonded pair correlation function (PCF) of the CG beads. The bonded CG potentials are obtained by simple inversion of the corresponding PDFs. The CG nonbonded potential is parameterized to the PCF using both an inversion procedure based on the Ornstein-Zernike equation with the Percus-Yevick approximation (OZPY{sup -1}) and a combination of OZPY{sup -1} with the iterative Boltzmann inversion (IBI) method (OZPY{sup -1}+IBI). As a simple one step method, the OZPY{sup -1} method possesses an advantage in computational efficiency. Using the potential from OZPY{sup -1} as an initial guess, the IBI method shows fast convergence. The coarse-grained molecular dynamics (CGMD) simulations of PEG chains with DP = 20 using potentials from both methods satisfactorily reproduce the structural properties from atomistic MD simulation of the same systems. The OZPY{sup -1}+IBI method yields better agreement than the OZPY{sup -1} method alone. The new CG model and CG potentials from OZPY{sup -1}+IBI method was further tested through CGMD simulation of PEG with DP = 40 system. No significant changes are observed in the comparison of PCFs from CGMD simulations of PEG with DP = 20 and 40 systems indicating that the potential is independent of chain length.

  17. Fluorescein prototropism within poly(ethylene glycol)s and their aqueous mixtures.

    PubMed

    Bhagi, Ambika; Pandey, Shubha; Pandey, Ashish; Pandey, Siddharth

    2013-05-01

    Depending on the solubilizing milieu and conditions, fluorescein may exist in one or more of its many prototropic forms [cationic, neutral (zwitterionic, quinoid, and lactone), monoanionic (phenolate and carboxylate), and dianionic]. Fluorescein prototropism is investigated in liquid poly(ethylene glycol)s (PEGs) of different average molecular weight (MW) and their aqueous mixtures using UV-vis absorbance along with static and time-resolved fluorescence spectroscopic techniques. Information regarding various prototropic forms of fluorescein in up to 30 wt % different average MW PEG-added aqueous buffers at varying pH reveals that addition of PEG causes lactonization of fluorescein in the milieu; higher the average MW of PEG, the more the lactonization is. Neat PEG200, PEG400, and PEG600 are found to support the dianionic form of fluorescein, while PEG1000 supports the neutral lactonized form. It is demonstrated that various prototropic forms of fluorescein may be generated within PEGs by addition of adequate amounts of acidic aqueous buffer. Significant bathochromic shift in absorbance and fluorescence band maxima of dianionic fluorescein as concentration of PEG200 is increased correlates well with hydrogen bond accepting basicity, hydrogen bond donating acidity, and dipolarity/polarizability of the aqueous PEG200 mixture. Interestingly, fluorescence emission from the cationic form of fluorescein is observed from dilute aqueous acidic media in the presence of high concentration of PEG200, whereas the fluorescence emission from cation in the absence of PEG200 is observed only from aqueous solutions of very high acidity (>5 M [H(+)]). Excited-state intensity decay is also used to support this outcome. It is proposed that, in the presence of a small amount of acid in PEG200, a highly acidic water-rich solvation microenvironment is formed around fluorescein, which converts its dianionic form to cationic form and considerably hinders the rapid deprotonation of the

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

    NASA Astrophysics Data System (ADS)

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Microgels of polyaspartamide and poly(ethylene glycol) derivatives obtained by γ-irradiation

    NASA Astrophysics Data System (ADS)

    Pitarresi, Giovanna; Licciardi, Mariano; Craparo, Emanuela Fabiola; Calderaro, Elio; Spadaro, Giuseppe; Giammona, Gaetano

    2002-09-01

    The copolymer PHG based on α, β-poly( N-2-hydroxyethyl)- DL-aspartamide (PHEA) functionalized with glycidyl methacrylate has been exposed in aqueous solution to a γ-ray source at different irradiation doses (2, 2.5 and 3.5 kGy), alone or in combination with poly(ethylene glycol)dimethacrylate (PEGDMA) or poly(ethylene glycol)diacrylate (PEGDA). The irradiation produces microgel systems that have been characterized by viscosity measurements. Lyophilization of microgels gives rise to samples able to swell instantaneously in water whereas their treatment with acetone produces swellable microparticles that have been characterized.

  1. Sorption of adamantanes on polyethylene glycol-modified graphitized thermal soot

    NASA Astrophysics Data System (ADS)

    Yashkin, S. N.; Ageeva, Yu. A.

    2014-04-01

    The thermodynamic characteristics of sorption of adamantane and its functional derivatives on graphitized thermal soot (GTS) modified with polyethylene glycol Carbowax 20M were determined by equilibrium gas chromatography. The resulting thermodynamic characteristics were analyzed and compared with the data measured for adamantanes on the surface of nonmodified GTS and polyethylene glycol deposited on an inert substrate. The solid carbon substrate was shown to affect the character of intermolecular interactions in the GTS-modifier system and the retention of framework compounds under the conditions of gas, liquid, and solid-state chromatography.

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

    PubMed

    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

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

    PubMed

    Kakinoki, Sachiro; Yui, Nobuhiko; Yamaoka, Tetsuji

    2013-11-01

    Four different dynamic biomaterial surfaces with different molecular architectures were prepared using two hydrophilic polymers: poly(ethylene glycol) and polyrotaxanes containing α-cyclodextrin. Either one or both terminals of the poly(ethylene glycol) or polyrotaxanes were immobilized onto a gold substrate via Au-S bonds, resulting in poly(ethylene glycol)-graft, polyrotaxanes-graft, poly(ethylene glycol)-loop, and polyrotaxanes-loop structures. Human platelet adhesion was suppressed more effectively on the graft surfaces than on the loop surfaces for both poly(ethylene glycol) and polyrotaxanes due to the high mobility of graft polymer chains with a free terminal. Moreover, the platelets adhered to the polyrotaxane surfaces much less than the poly(ethylene glycol) surfaces, possibly because of the mobile nature of the α-cyclodextrin molecules that were threaded on the poly(ethylene glycol) chain. Actin filament assembly in adherent platelets was also greatly prevented on the poly(ethylene glycol)/polyrotaxanes-graft surfaces in comparison with the corresponding loop surfaces. A clear correlation between the numbers and areas of adherent platelets on these surfaces suggests that platelet adhesion and activation were dominated by the platelet GPIIb/IIIa-adsorbed fibrinogen interaction. These results indicate that both of the different modes of dynamic features, sliding/rotation of α-cyclodextrin and polymer chain mobility, effectively suppressed platelet adhesion in spite of the similar hydrophilicity. This research affords a novel chemical strategy for designing hemocompatible biomaterial surfaces. PMID:23048065

  4. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10472 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products. (a) Chemical substance and... with epichlorohydrin-polyethylene glycol reaction products. 721.10472 Section 721.10472 Protection...

  5. 40 CFR 721.10472 - 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10472 1,3-Benzenedimethanamine, polymers with epichlorohydrin-polyethylene glycol reaction products. (a) Chemical substance and... with epichlorohydrin-polyethylene glycol reaction products. 721.10472 Section 721.10472 Protection...

  6. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene glycol (mean molecular weight 200-9,500). 172.820 Section 172.820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR...

  7. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene glycol (mean molecular weight 200-9,500). 172.820 Section 172.820 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR...

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

    EPA Science Inventory

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    ERIC Educational Resources Information Center

    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,…

  11. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ...This regulation establishes an exemption from the requirement of a tolerance for residues of methacrylic acid-methyl methacrylate- polyethylene glycol monomethyl ether methacrylate graft copolymer when used as an inert ingredient in a pesticide chemical formulation. Akzo Noel Surface Chemistry LLC submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an......

  12. One step synthesis of C-dots by microwave mediated caramelization of poly(ethylene glycol).

    PubMed

    Jaiswal, Amit; Ghosh, Siddhartha Sankar; Chattopadhyay, Arun

    2012-01-11

    A rapid, simple and one step microwave mediated method for synthesizing C-dots using poly(ethylene glycol) (PEG) as a precursor and passivating agent is reported. The C-dots possessed low cytotoxicity, were amenable to separation by electrophoresis, photostable and entered cancer cells, making them suitable candidates for bioimaging and biolabelling. PMID:22075768

  13. Effect of Short Chain Poly(ethylene glycol)s on the Hydration Structure and Dynamics around Human Serum Albumin.

    PubMed

    Samanta, Nirnay; Luong, Trung Quan; Das Mahanta, Debasish; Mitra, Rajib Kumar; Havenith, Martina

    2016-01-26

    We report the changes in the hydration dynamics around a globular protein, human serum albumin (HSA), in the presence of two short chain crowding agents, namely poly(ethylene glycol)s (PEG 200 and 400). The change in the network water structure is investigated using FTIR spectroscopy in the far-infrared (FIR) frequency range. Site specific changes are obtained by time-resolved fluorescence spectroscopic technique using the intrinsic fluorophore tryptophan (Trp214) of HSA. The collective hydration dynamics of HSA in the presence of PEG molecules are obtained using terahertz (THz) time domain spectroscopy (TTDS) and high intensity p-Ge THz measurements. Our study affirms a considerable perturbation of HSA hydration beyond a critical concentration of PEG. PMID:26720549

  14. Pressure and temperature dependence of excess enthalpies of methanol + tetraethylene glycol dimethyl ether and methanol + polyethylene glycol dimethyl ether 250

    SciTech Connect

    Lopez, E.R.; Coxam, J.Y.; Fernandez, J.; Grolier, J.P.E.

    1999-12-01

    The excess molar enthalpies at 323.15 K, 373.15 K, and 423.15 K, at 8 MPa, are reported for the binary mixtures methanol + tetraethylene glycol dimethyl ether (TEGDME) and methanol + poly(ethylene glycol) dimethyl ether 250 (PEGDME 250). Excess molar enthalpies were determined with a Setaram C-80 calorimeter equipped with a flow mixing cell. For both systems, the excess enthalpies are positive over the whole composition range, increasing with temperature. The H{sup E}(x) curves are slightly asymmetrical, and their maxima are skewed toward the methanol-rich region. The excess enthalpies slightly change with the pressure, the sign of this change being composition-dependent. In the case of mixtures with TEGDME, the experimental H{sup E} values have been compared with those predicted with the Gmehling et al. version of UNIFAC (Dortmund) and the Nitta-Chao and DISQUAC group contribution models.

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

    PubMed

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

    2016-05-01

    The well-defined amphiphilic poly(ethylene glycol)-block-poly(propylene glycol) copolymer containing 1, 2, 3-triazole moiety and multiple ester bonds (PEG-click-PPG) was prepared by click reaction strategy. The PEG-click-PPG copolymer can self-assemble into spherical micelles in aqueous solution. It is found that high intensity focused ultrasound (HIFU) can open the copolymer PEG-click-PPG micelles and trigger the release of the payload in the micelle. The multiple ester bonds introduced in the junction point of the copolymer chain through click reactions were cleaved under HIFU, and leads to the disruption of the copolymer micelle and fast release of loaded cargo. The click reaction provides a convenient way to construct ultrasound responsive copolymer micelles with weak bonds. PMID:26703197

  16. Extraction of actinides into aqueous polyethylene glycol solutions from carbonate media in the presence of alizarin complexone

    SciTech Connect

    Molochnikova, N.P.; Frenkel', V.Ya.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-01-01

    Actinide extraction in a two-phase aqueous system based on polyethylene glycol from carbonate solutions of various compositions in presence of alizarin complexone is studied. It is shown that the nature of the alkali metals affects actinide extraction into the polyethylene glycol phase. Tri- and tetravalent actinides are extracted maximally from sodium carbonate solutions. Separation of actinides in different oxidation states is more effective in potassium carbonate solutions. The behavior of americium in different oxidation states in the system carbonate-polyethylene glycol-complexone is studied. The possibility of extraction separation of microamount of americium(V) from curium in carbonate solutions in presence of alizarin complexone is shown.

  17. Synthesis, Characterization, and Size Control of Zinc Sulfide Nanoparticles Capped by Poly(ethylene glycol)

    NASA Astrophysics Data System (ADS)

    Allehyani, S. H. A.; Seoudi, R.; Said, D. A.; Lashin, A. R.; Abouelsayed, A.

    2015-11-01

    Zinc sulfide nanoparticles with controllable size were synthesized by chemical precipitation. Results from transmission electron microscopy and x-ray powder diffraction showed the samples were grown with the cubic phase. Particle size was varied by varying the molar ratio of zinc chloride to sodium sulfide in the presence of poly(ethylene glycol). The optical band gap was calculated on the basis of ultraviolet-visible spectroscopy and ranged from 4.13 to 4.31 eV depending on particle size. Surface passivation and adsorption of poly (ethylene glycol) on the nanoparticles was explained on the basis of Fourier-transform infrared measurements.

  18. On the spectral behavior of an ionic styryl dye: effect of micelle-polyethylene-block-polyethylene glycol diblock copolymer assembly.

    PubMed

    Sahoo, Dibakar; Bhattacharya, Prosenjit; Chakravorti, Sankar

    2009-10-15

    The interaction of anionic micelle sodium dodecyl sulfate (SDS) and amphiphilic block copolymers polyethylene-b-polyethylene glycol (PE-b-PEG) and the sharp change of excited-state charge-transfer complex photophysics of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide (DASPMI) inside of the supramolecular assembly have been addressed in the paper. The dramatic enhancement of emission intensity of DASPMI incorporated inside of the nanostructure formed by micellar and polymeric chains indicates a completely different environment compared to that in the water and micellar system. A huge increase in the rotational relaxation time obtained from time-resolved anisotropy decay and the value of the order parameter is indicative of a very restrictive regime in the self-assembly system. The wobbling and translational motion of the probe is also restricted inside of the micelle-polymer aggregate due to the presence of polymer chains. The translational diffusion coefficient is drastically reduced due to the aggregation. PMID:19761273

  19. Basic Physicochemical Properties of Polyethylene Glycol Coated Gold Nanoparticles that Determine Their Interaction with Cells.

    PubMed

    Del Pino, Pablo; Yang, Fang; Pelaz, Beatriz; Zhang, Qian; Kantner, Karsten; Hartmann, Raimo; Martinez de Baroja, Natalia; Gallego, Marta; Möller, Marco; Manshian, Bella B; Soenen, Stefaan J; Riedel, René; Hampp, Norbert; Parak, Wolfgang J

    2016-04-25

    A homologous nanoparticle library was synthesized in which gold nanoparticles were coated with polyethylene glycol, whereby the diameter of the gold cores, as well as the thickness of the shell of polyethylene glycol, was varied. Basic physicochemical parameters of this two-dimensional nanoparticle library, such as size, ζ-potential, hydrophilicity, elasticity, and catalytic activity ,were determined. Cell uptake of selected nanoparticles with equal size yet varying thickness of the polymer shell and their effect on basic structural and functional cell parameters was determined. Data indicates that thinner, more hydrophilic coatings, combined with the partial functionalization with quaternary ammonium cations, result in a more efficient uptake, which relates to significant effects on structural and functional cell parameters. PMID:27028669

  20. Methoxy poly(ethylene glycol) conjugated doxorubicin micelles for effective killing of cancer cells.

    PubMed

    Zhang, Liming; Xia, Kai; Deng, Yan; Li, Song; Zhang, Chuanxiang; Lu, Zhuoxuan; He, Nongyue

    2014-08-01

    Methoxy poly(ethylene glycol) conjugated doxorubicin (mPEG-DOX) micelles are prepared for delivering drug effectively. The core of the unimolecular micelle is a DOX (doxorubicin) which is an anti-cancer chemotherapy drug, while the outer hydrophilic shell is composed of poly(ethylene glycol) (PEG) segments. Dynamic light scattering (DLS) analysis shows that the unimolecular micelles are uniform with a mean hydrodynamic diameter around 250 nm. The mPEG-DOX micelles can be internalized by the cancer cells and exhibit good cell uptake by the fluorescence microscopy. Obvious cytotoxicity is also observed when the concentration (count on DOX) is over 1 μg/mL. These findings indicate that these unique unimolecular micelles may offer a very promising approach for targeted cancer therapy. PMID:25936136

  1. Conformational characteristics of polyethylene glycol macromolecules in aqueous solutions according to refractometry data

    NASA Astrophysics Data System (ADS)

    Abbasov, H. F.

    2014-06-01

    The aqueous solutions of polyethylene glycols with molecular masses of 600, 1000, 1500, 3000, 6000, and 20000 were studied by refractometry. The conformational polarizabilities, mean-square distances between the ends of the macromolecular chain, segment lengths, and the number of Kuhn segments in a macromolecule were determined using the Lorentz-Lorentz equation. The polarizability of a hydrated macro-molecule was represented as the sum of polarizabilities of the nonhydrated macromolecule with retained conformation and polarizabilities of the water molecules involved in hydration of macromolecules. The size of macromolecules stabilized starting from a certain concentration. It was concluded that the initial concentration of stabilization shifts toward low concentrations as the molecular mass of polyethylene glycol increases. The dependence of the mean-square distance between the ends of the macromolecular chain on the number of Kuhn segments was expressed as the exponential function with index 0.3.

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

    SciTech Connect

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

    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.

  3. Poly(ethylene glycol)-or silicone-modified hyaluronan for contact lens wetting agent applications.

    PubMed

    Paterson, Stefan M; Liu, Lina; Brook, Michael A; Sheardown, Heather

    2015-08-01

    Hyaluronan (HA) is a hydrophilic biopolymer that has been explored as a wetting agent in contact lens applications. In this study, HA was modified with siloxy or polyethylene glycol moieties using click chemistry to make it more soluble in monomer solutions used to synthesize model contact lens materials; unmodified HA was not soluble in the same monomer solutions. The water contents of the silicone hydrogels were not increased by the presence of modified HA, nor was there a decrease in the surface contact angle. However, modified HA did lead to a reduction in lysozyme adsorption in some cases. The leaching rate of HA modified with polyethylene glycol from a 78:22 DMA:TRIS(OH) hydrogel was significantly slower than for unmodified HA. PMID:25504586

  4. Liquid-liquid distribution of B group vitamins in polyethylene glycol-based systems

    NASA Astrophysics Data System (ADS)

    Korenman, Ya. I.; Zykov, A. V.; Mokshina, N. Ya.

    2011-05-01

    General regularities of the liquid-liquid distribution of B1, B2, B6, and B12 vitamins in aqueous polyethylene glycol (PEG-2000, PEG-5000) solution-aqueous salt solution systems are studied. The influence of the salting-out agent, the concentration of the polymer, and its molecular weight on the distribution coefficients and recovery factors of the vitamins are considered. Equations relating the distribution coefficients (log D) to the polymer concentration are derived.

  5. Complete Genome Sequence of Sphingopyxis terrae Strain 203-1 (NBRC 111660), a Polyethylene Glycol Degrader.

    PubMed

    Ohtsubo, Yoshiyuki; Nonoyama, Shouta; Nagata, Yuji; Numata, Mitsuru; Tsuchikane, Keiko; Hosoyama, Akira; Yamazoe, Atsushi; Tsuda, Masataka; Fujita, Nobuyuki; Kawai, Fusako

    2016-01-01

    The complete genome sequence of Sphingopyxis terrae strain 203-1, which is capable of growing on polyethylene glycol, was determined. The genome consisted of a chromosome with a size of 3.98 Mb and a plasmid with a size of 4,328 bp. The strain was deposited to the National Institute of Technology and Evaluation (Tokyo, Japan) under the number NBRC 111660. PMID:27284143

  6. Complete Genome Sequence of Sphingopyxis terrae Strain 203-1 (NBRC 111660), a Polyethylene Glycol Degrader

    PubMed Central

    Nonoyama, Shouta; Nagata, Yuji; Numata, Mitsuru; Tsuchikane, Keiko; Hosoyama, Akira; Yamazoe, Atsushi; Tsuda, Masataka; Fujita, Nobuyuki; Kawai, Fusako

    2016-01-01

    The complete genome sequence of Sphingopyxis terrae strain 203-1, which is capable of growing on polyethylene glycol, was determined. The genome consisted of a chromosome with a size of 3.98 Mb and a plasmid with a size of 4,328 bp. The strain was deposited to the National Institute of Technology and Evaluation (Tokyo, Japan) under the number NBRC 111660. PMID:27284143

  7. Protection of cellulose synthesis in detached cotton fibers by polyethylene glycol

    SciTech Connect

    Carpita, N.C.; Delmer, D.P.

    1980-11-01

    Detachment of the cotton fiber cell from the ovule results in loss of over 90% of the in vivo capacity for synthesis of (/sup 14/C)cellulose from (/sup 14/C)glucose. However, over 50% of the capacity for cellulose synthesis in the detached fiber population is protected when polyethylene glycol 4000 is present during detachment and incubation. Radioautography shows that approximately full capacity is restored in about half the fibers, whereas the other half of the population are incapable of cellulose synthesis from supplied glucose. The rate of cellulose synthesis in such fibers has a pH optimum of 6 and the optimum polyethylene glycol 4000 concentration is 0.06 molal (-9 bars). Cellulose synthesis in such detached fibers is synergistically stimulated by Ca/sup 2 +/ and Mg/sup 2 +/ and inhibited by K/sup +/. Evidence is presented which indicates that the protection by polyethylene glycol 4000 is due to its ability to promote membrane resealing, which seems to be required for protecting cellulose synthesis in the detached fiber; however, the requirement for membrane integrity is not exclusively involved in the maintenance of an energy generating system for the synthesis. The possibility that a membrane potential may be required for maintaining an active cellulose synthesizing system is discussed.

  8. Complete free energy landscape and statistical thermodynamics of single poly(ethylene glycol) molecules

    NASA Astrophysics Data System (ADS)

    Staple, Douglas; Hanke, Felix; Kreuzer, Hans Jürgen

    2007-03-01

    In this paper, we revisit the statistical mechanics of poly(ethylene glycol) with the intention to check ad hoc approximations made in previous works, namely to keep all C O bonds along the chain in the trans configuration. The theory developed here includes all the bonds on an equal footing. Starting with density functional theory calculations for the ethylene glycol monomer, dimer and trimer one can determine all the energetic and geometric parameters needed for a rotationally isomeric state model with interactions between nearest neighbour monomers included. The properties of short molecules are presented in detail, including the force-extension curves, end-to-end distributions, and also a discussion of the local helix properties. Finally, we use the transfer matrix method for long chains of 200 ethylene glycol monomers, i.e. 600 bonds. The agreement with the experimental force-extension curve is excellent.

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

    PubMed

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

    2012-01-01

    Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA) as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P) precipitates on the composite surface as proven from SEM and XRD analysis. PMID:22666129

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

    PubMed Central

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

    2012-01-01

    Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA) as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P) precipitates on the composite surface as proven from SEM and XRD analysis. PMID:22666129

  11. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  12. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  13. 40 CFR 721.4040 - Glycols, polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetra-methylbutyl)phenyl ether, sodium...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Glycols, polyethylene-, 3-sulfo-2... CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4040 Glycols, polyethylene..., polyethylene-, 3-sulfo-2-hydroxypropyl-p-(1,1,3,3-tetramethyl butyl)phenyl ether, sodium salt (P-90-1565)...

  14. Preparation of Microstructure Molds of Montmorillonite/Polyethylene Glycol Diacrylate and Multi-Walled Carbon Nanotube/Polyethylene Glycol Diacrylate Nanocomposites for Miniaturized Device Applications.

    PubMed

    Kim, Young Ho; Sohn, Jeong-Woo; Woo, Youngjae; Hong, Joo-Hyun; Kim, Gyu Man; Kang, Bong Keun; Park, Juyoung

    2015-10-01

    Environmentally friendly microstructure molds with montmorillonite (MMT) or multi-walled carbon nanotube (MWCNT) reinforced polyethylene glycol diacrylate (PEGDA) nanocomposites have been prepared for miniaturized device applications. The micropatterning of MMT/PEGDA and MWCNT/PEGDA with 0.5 to 2.0 wt% of MMTs and MWCNTs was achieved through a UV curing process with micro-patterned masks. Hexagonal dot arrays and complex patterns for microstructures of the nanocomposites were produced and characterized with an optical microscope; their thermal properties were studied by thermogravimetric analysis (TGA). The TGA results showed that these nanocomposites were thermally stable up to 350 °C. Polydimethylsiloxane thin replicas with different microstructures were prepared by a casting method using the microstructured nanocomposites as molds. It is considered that these microstructure molds of the nanocomposites can be used as microchip molds to fabricate nanobio-chips and medical diagnostic chip devices. PMID:26726429

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

    PubMed

    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

    NASA Astrophysics Data System (ADS)

    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. Impedance Spectroscopy Study of Composite Thin Films of Hydrated Polyethylene Glycol

    SciTech Connect

    Al-Hamarneh, Ibrahim F.; Pedrow, Patrick D.; Goheen, Steven C.; Hartenstine, M. J.

    2007-10-01

    A polyethylene glycol (PEG) polymer was synthesized using a dip coating procedure on 316L stainless steel (SS) substrate pre-coated with a primer that consisted of radio frequency RF inductively coupled plasma-polymerized di (ethylene glycol) vinyl ether (EO2V). The primer and PEG composite film was studied with profilometer, optical microscope, scanning electron microscope (SEM), and a tape test to evaluate thickness, coverage, morphology, and adhesion, respectively. Response of the PEG composite film to an applied AC voltage was studied as a function of hydration state using impedance spectroscopy (IS). A resistor/capacitor network was used to interpret the impedance spectra. Electrical capacitance of the PEG film decreased with an exponentially decaying term as dehydration progressed. PEG film capacitance decay was consistent with a model describing water molecules diffusing through the PEG film.

  18. Impact compressibility of a poly(ethylene glycol)-based nanocomposite fluid

    NASA Astrophysics Data System (ADS)

    Bragov, A. M.; Igumnov, L. A.; Konstantinov, A. Yu.; Lomunov, A. K.; Antonov, F. K.; Mossakovskii, P. A.

    2014-10-01

    The behavior of a poly(ethylene glycol)-based nanocomposite shear thickening fluid (STF) under impact loading conditions has been experimentally studied using the Kolsky method and related techniques. The dependence of the pressure in the STF on the volume strain magnitude has been determined. It is established that the radial and axial components of the stress tensor almost coincide, which shows that the material behaves like an incompressible liquid. The character of the stress-strain curves (hysteresis) indicates that the STF is characterized by some energy dissipation in the load-unload cycle.

  19. Complete Genome Sequence of Sphingopyxis macrogoltabida Strain 203N (NBRC 111659), a Polyethylene Glycol Degrader.

    PubMed

    Ohtsubo, Yoshiyuki; Nonoyama, Shouta; Nagata, Yuji; Numata, Mitsuru; Tsuchikane, Keiko; Hosoyama, Akira; Yamazoe, Atsushi; Tsuda, Masataka; Fujita, Nobuyuki; Kawai, Fusako

    2016-01-01

    We determined the complete genome sequence of Sphingopyxis macrogoltabida strain 203N, a polyethylene glycol degrader. Because the PacBio assembly (285× coverage) seemed to be full of nucleotide-level mismatches, the Newbler assembly of MiSeq mate-pair and paired-end data was used for finishing and the PacBio assembly was used as a reference. The PacBio assembly carried 414 nucleotide mismatches over 5,953,153 bases of the 203N genome. PMID:27284142

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

    NASA Astrophysics Data System (ADS)

    Das, S.; Ghosh, A.

    2016-05-01

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

  1. Polyethylene glycol-directed SnO2nanowires for enhanced gas-sensing properties

    NASA Astrophysics Data System (ADS)

    Yin, Ya-Xia; Jiang, Ling-Yan; Wan, Li-Jun; Li, Cong-Ju; Guo, Yu-Guo

    2011-04-01

    SnO2nanowires with lengths in the tens of micrometres range have been synthesized on a large scale via a facile polyethylene glycol-directed method at ambient temperature followed by a suitable thermal treatment of the precursor nanowires. The morphology of the precursor of the SnO2nanowires is tunable by changing the concentration of either SnCl2 or polyethylene glycol. After calcination, the resulting SnO2nanowires retain a similar shape to the precursor, but with hierarchical architecture, which can be considered as one-dimensional nanowires assembled by interconnected SnO2nanoparticles with a high surface-to-volume ratio. The SnO2nanowires are investigated with XRD, SEM, TEM, and gas sensing tests for detecting CO and H2. It is found that the present SnO2nanowires exhibit a remarkable sensitivity and low detection limit (10 ppm for H2), as well as good reproducibility and short response/recovery times, which benefit from the unique hierarchical structure with a high surface-to-volume ratio and the 3D network formed by the nanowires.SnO2nanowires with lengths in the tens of micrometres range have been synthesized on a large scale via a facile polyethylene glycol-directed method at ambient temperature followed by a suitable thermal treatment of the precursor nanowires. The morphology of the precursor of the SnO2nanowires is tunable by changing the concentration of either SnCl2 or polyethylene glycol. After calcination, the resulting SnO2nanowires retain a similar shape to the precursor, but with hierarchical architecture, which can be considered as one-dimensional nanowires assembled by interconnected SnO2nanoparticles with a high surface-to-volume ratio. The SnO2nanowires are investigated with XRD, SEM, TEM, and gas sensing tests for detecting CO and H2. It is found that the present SnO2nanowires exhibit a remarkable sensitivity and low detection limit (10 ppm for H2), as well as good reproducibility and short response/recovery times, which benefit from the

  2. Polymer adsorption on platinum: surface coverage determination using iodide-125. [Polyethylene glycol terephthalate

    SciTech Connect

    Ellis, T.M.; Van de Mark, M.R.; mi, FL

    1981-10-01

    Adsorption of iodide-125, a ..gamma.. emitter, was used as a quantitative methodology for polymer adsorption surface coverage analysis. Adsorption of I-125 on clean platinum produced surface elemental ratios of I:Pt of 1:4. The technique was applied to the adsorption of polyethylene glycol terephthalate from trifluoroacetic acid on platinum flags with a 2-cm/sup 2/ surface area. This polymer adsorption is approximated by a logarithmic relationship similar to the Temkin isotherm. Polymer coverage attained up to 99.6% of the surface.

  3. Study on Biodegradation Process of Polyethylene Glycol with Exponential Glowth of Microbial Population

    NASA Astrophysics Data System (ADS)

    Watanabe, Masaji; Kawai, Fusako

    Biodegradation of polyethylene glycol is studied mathematically. A mathematical model for depolymerization process of exogenous type is described. When a degradation rate is a product of a time factor and a molecular factor, a time dependent model can be transformed into a time independent model, and techniques developed in previous studies can be applied to the time independent model to determine the molecular factor. The time factor can be determined assuming the exponential growth of the microbial population. Those techniques are described, and numerical results are presented. A comparison between a numerical result and an experimental result shows that the mathematical method is appropriate for practical applications.

  4. The influence of poly(ethylene glycol) ether tetrasuccinimidyl glutarate on the structural, physical, and biological properties of collagen fibers.

    PubMed

    Sanami, Mohammad; Sweeney, India; Shtein, Zvi; Meirovich, Sigal; Sorushanova, Anna; Mullen, Anne Maria; Miraftab, Mohsen; Shoseyov, Oded; O'Dowd, Colm; Pandit, Abhay; Zeugolis, Dimitrios I

    2016-07-01

    Various chemical, natural, or synthetic in origin, crosslinking methods have been proposed over the years to stabilise collagen fibers. However, an optimal method has yet to be identified. Herein, we ventured to assess the potential of 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate, as opposed to glutaraldehyde (GTA), genipin and carbodiimide, on the structural, physical and biological properties of collagen fibers. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate induced an intermedium surface smoothness, denaturation temperature and swelling. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate fibers had significantly higher stress at break values than the carbodiimide fibers, but significantly lower than the GTA and genipin fibers. With respect to strain at break, no significant difference was observed among the crosslinking treatments. The 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate fibers exhibited significantly higher cell metabolic activity and DNA concentration that all other crosslinking treatments, promoted consistently cellular elongation along the longitudinal fiber axis and by day 7 they were completely covered by cells. Collectively, this work clearly demonstrates the potential of 4-star poly(ethylene glycol) ether tetrasuccinimidyl glutarate as collagen crosslinker. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 914-922, 2016. PMID:25952265

  5. Cutaneous toxicity studies with methoxy polyethylene glycol-350 (MPEG-350) in rats and rabbits.

    PubMed

    Hermansky, S J; Leung, H W

    1997-01-01

    The methoxy polyethylene glycols (MPEGs), also referred to as polyethylene glycol methyl ethers, are high molecular weight polymers similar in structure and nomenclature to the polyethylene glycols. Because of the potential for repeated cutaneous exposure of humans to MPEG-350 and the known toxicity of lower alkylene glycol ethers such as ethylene glycol monomethyl ether (EGME), studies were conducted to evaluate the potential toxicity and irritation of MPEG-350 following repeated, cutaneous treatment. New Zealand White rabbits were cutaneously treated with 1.0 ml of either undiluted MPEG-350 or a 50% solution of MPEG-350 in 0.1% methyl cellulose in distilled water for 9 or 90 days. CD(SD)BR rats were cutaneously treated with up to 5 g/kg/day of undiluted MPEG-350 for 14 or 28 days. The treatment area was not occluded but animals were fitted with Elizabethan collars during treatment. Rabbits were treated 6 hr/day 5 days/wk. Rats were treated for at least 19 hr/day (at weekends, the exposure time was approximately 70 hr). None of the animals died. Slight decreases in mean absolute body weight of all dose groups of male rats as compared with the concurrent control group may have been related to minimal toxicity of the test substance but was probably secondary to the dosing procedures. Signs of slight cutaneous irritation were observed in many treated animals of both species but only a few rabbits had confirmatory microscopic diagnoses while none of the rats had microscopic changes in the skin. Slight decreases in the mean absolute weight of the testes, spleen and thymus were observed in rats treated with 5 g undiluted MPEG-350/kg/day for 14 days. Similar changes were not observed in rats following 28 days of treatment. There were no microscopic changes in any of these organs except for one rat that had moderate to high aspermatogenesis and multinucleated spermatids. There were no microscopic changes observed in the testes of any other animals (including rats treated

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Recent advances in crosslinking chemistry of biomimetic poly(ethylene glycol) hydrogels

    PubMed Central

    Lin, Chien-Chi

    2015-01-01

    The design and application of biomimetic hydrogels have become an important and integral part of modern tissue engineering and regenerative medicine. Many of these hydrogels are prepared from synthetic macromers (e.g., poly(ethylene glycol) or PEG) as they provide high degrees of tunability for matrix crosslinking, degradation, and modification. For a hydrogel to be considered biomimetic, it has to recapitulate key features that are found in the native extracellular matrix, such as the appropriate matrix mechanics and permeability, the ability to sequester and deliver drugs, proteins, and or nucleic acids, as well as the ability to provide receptor-mediated cell-matrix interactions and protease-mediated matrix cleavage. A variety of chemistries have been employed to impart these biomimetic features into hydrogel crosslinking. These chemistries, such as radical-mediated polymerizations, enzyme-mediated crosslinking, bio-orthogonal click reactions, and supramolecular assembly, may be different in their crosslinking mechanisms but are required to be efficient for gel crosslinking and ligand bioconjugation under aqueous reaction conditions. The prepared biomimetic hydrogels should display a diverse array of functionalities and should also be cytocompatible for in vitro cell culture and/or in situ cell encapsulation. The focus of this article is to review recent progress in the crosslinking chemistries of biomimetic hydrogels with a special emphasis on hydrogels crosslinked from poly(ethylene glycol)-based macromers. PMID:26029357

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

    PubMed

    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

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

    PubMed

    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. PMID:19572700

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

    PubMed

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

    2011-12-15

    The hypothesis regarding preferential biodegradation of surfactants applied for enhancement of microbial hydrocarbons degradation was studied. At first the microbial degradation of sole Triton X-100 by soil isolated hydrocarbon degrading bacterial consortium was confirmed under both full and limited aeration with nitrate as an electron acceptor. Triton X-100 (600 mg/l) was utilized twice as fast for aerobic conditions (t(1/2)=10.3h), compared to anaerobic conditions (t(1/2)=21.8h). HPLC/ESI-MS analysis revealed the preferential biodegradation trends in both components classes of commercial Triton X-100 (alkylphenol ethoxylates) as well as polyethylene glycols. The obtained results suggest that the observed changes in the degree of ethoxylation for polyethylene glycol homologues occurred as a consequence of the 'central fission' mechanism during Triton X-100 biodegradation. Subsequent experiments with Triton X-100 at approx. CMC concentration (150 mg/l) and diesel oil supported our initial hypothesis that the surfactant would become the preferred carbon source even for hydrocarbon degrading bacteria. Regardless of aeration regimes Triton X-100 was utilized within 48-72 h. Efficiency of diesel oil degradation was decreased in the presence of surfactant for aerobic conditions by approx. 25% reaching 60 instead of 80% noted for experiments without surfactant. No surfactant influence was observed for anaerobic conditions. PMID:21996621

  12. Polyethylene glycol inhibits intestinal neoplasia and induces epithelial apoptosis in Apc(min) mice.

    PubMed

    Roy, Hemant K; Gulizia, James; DiBaise, John K; Karolski, William J; Ansari, Sajid; Madugula, Madhavi; Hart, John; Bissonnette, Marc; Wali, Ramesh K

    2004-11-01

    Efficacy of a safe and clinically utilized polyethylene glycol formulation (PEG-3350) to suppress intestinal tumors was investigated in the Apc(min) mouse-model of experimental carcinogenesis. Furthermore, based on our previous finding on the induction of apoptosis in HT-29 cells by PEG, we evaluated its ability to stimulate epithelial cell apoptosis in both Apc(min) mouse as well as AOM-treated rat as a potential molecular mechanism of chemoprevention. Twenty-two Apc(min) mice were randomized equally to PEG or vehicle (control) supplementation. Tumors were scored and uninvolved intestinal mucosal apoptosis was assayed using a modified terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) assay and by immunohistochemical detection of cleaved caspase-3. Supplementation of Apc(min) mice with 10% PEG 3350 (in drinking water) resulted in a 48% (P<0.05) reduction in intestinal tumor burden and induced 2-3 fold increase in mucosal apoptosis. Dietary supplementation of polyethylene glycol (5%) also stimulated colonic mucosal apoptosis 4-5 fold in AOM-treated rats, the regimen that we previously reported to reduce tumor burden by 76% (P<0.05). In summary, we demonstrate, for the first time, that PEG does protect against Apc(min) mouse tumorigenesis. The correlation between pro-apoptotic actions and chemopreventive efficacy of PEG in these models strongly implicates induction of apoptosis as one of the impending mechanisms of chemoprevention. PMID:15374630

  13. Polyethylene glycol-induced heteroassociation of malate dehydrogenase and citrate synthase

    SciTech Connect

    Merz, J.M.; Webster, T.A.; Appleman, J.R.; Manley, E.R.; Yu, H.A.; Datta, A.; Ackerson, B.J.; Spivey, H.O.

    1987-10-01

    Studies by dynamic and total intensity light scattering, ultracentrifugation, electron microscopy, and chemical crosslinking on solutions of the pig heart mitochondrial enzymes, malate dehydrogenase and citrate synthase (separately and together) demonstrate that polyethylene glycol induces very large homoassociations of each enzyme, and still larger heteroenzyme complexes between these two enzymes in the solution phase. Specificity of this heteroassociation is indicated by the facts that heteroassociations with bovine serum albumin were not observed for either the mitochondrial dehydrogenase or the synthase or between cytosolic malate dehydrogenase and citrate synthase. The weight fraction of the enzymes in the mitochondrial dehydrogenase-synthase associated particles in the solution phase was less than 0.03% with the dilute conditions used in the dynamic light scattering measurements. Neither palmitoyl-CoA nor other solution conditions tested significantly increased this weight fraction of associated enzymes in the solution phase. Because of the extremely low solubility of the associated species, however, the majority of the enzymes can be precipitated as the heteroenzyme complex. This precipitation is a classical first-order transition in spite of the large particle sizes and broad size distribution. Ionic effects on the solubility of the heteroenzyme complex appear to be of general electrostatic nature. Polyethylene glycol was found to be more potent in precipitating this complex than dextrans, polyvinylpyrrolidones, ficoll, and beta-lactoglobulin.

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

    PubMed

    Mesnukul, A; Yodkhum, K; Mahadlek, J; Phaechamud, T

    2010-01-01

    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. PMID:20582196

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2016-02-10

    We synthesized agarose-polycaprolactone (Agr-PCL) bicomponent and Agr-polyethylene glycol-PCL (Agr-PEG-PCL) tricomponent amphiphilic co-network (APCN) gels by the sequential nucleophilic substitution reaction between amine-functionalized Agr and activated halide terminated PCL or PCL-b-PEG-b-PCL copolymer for the sustained and localized delivery of hydrophilic and hydrophobic drugs. The biodegradability of the APCNs was confirmed using lipase and by hydrolytic degradation. These APCN gels displayed good cytocompatibility and blood compatibility. Importantly, these APCN gels exhibited remarkably high drug loading capacity coupled with sustained and triggered release of both hydrophilic and hydrophobic drugs. PEG in the APCNs lowered the degree of phase separation and enhanced the mechanical property of the APCN gels. The drug loading capacity and the release kinetics were also strongly influenced by the presence of PEG, the nature of release medium, and the nature of the drug. Particularly, PEG in the APCN gels significantly enhanced the 5-fluorouracil loading capacity and lowered its release rate and burst release. Release kinetics of highly water-soluble gemcitabine hydrochloride and hydrophobic prednisolone acetate depended on the extent of water swelling of the APCN gels. Cytocompatibility/blood compatibility and pH and enzyme-triggered degradation together with sustained release of drugs show great promise for the use of these APCN gels in localized drug delivery and tissue engineering applications. PMID:26760672

  17. Effects of hydrophobic drug polyesteric core interactions on drug loading and release properties of poly(ethylene glycol) polyester poly(ethylene glycol) triblock core shell nanoparticles

    NASA Astrophysics Data System (ADS)

    Khoee, Sepideh; Hassanzadeh, Salman; Goliaie, Bahram

    2007-05-01

    BAB amphiphilic triblock copolymers consisting of poly(ethylene glycol) (B) (PEG) as the hydrophilic segment and different polyesters (A) as the hydrophobic block were prepared by a polycondensation reaction as efficient model core-shell nanoparticles to assay the effect of interactions between the hydrophobic drug and the polyesteric core in terms of drug loading content and release profile. PEG-poly(hexylene adipate)-PEG (PEG-PHA-PEG) and PEG-poly(butylene adipate)-PEG (PEG-PBA-PEG) to PEG-poly(ethylene adipate)-PEG (PEG-PEA-PEG) core-shell type nanoparticles entrapping quercetin (an anticarcinogenic, allergy inhibitor and antibacterial agent), were prepared by a nanoprecipitation method and characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and x-ray diffraction (XRD) techniques. It was found that the obtained nanoparticles showed a smooth surface and spherical shape with controllable sizes in the range of 64-74 nm, while drug loading varied from 7.24% to 19% depending on the copolymer composition and the preparation conditions. The in vitro release behaviour exhibited a sustained release and was affected by the polymer-drug interactions. UV studies revealed the presence of hydrogen bonding as the main existing interaction between quercetin and polyesters in the nanosphere cores.

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

    PubMed

    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

  19. 40 CFR 721.10505 - Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphoric acid, mixed mono- and... Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12-16-alkyl... identified as phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol...

  20. 40 CFR 721.10505 - Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphoric acid, mixed mono- and... Phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol mono-C12-16-alkyl... identified as phosphoric acid, mixed mono- and diesters with 2-ethyl-1-hexanol and polyethylene glycol...

  1. Fermentative degradation of nonionic surfactants and polyethylene glycol by enrichment cultures and by pure cultures of homoacetogenic and propionate-forming bacteria.

    PubMed Central

    Wagener, S; Schink, B

    1988-01-01

    Linear alkyl ethoxylates (polyethylene glycol alkyl ethers) were fermented completely to methane and CO2 in enrichment cultures inoculated with anoxic sewage sludge. Long-chain fatty acids were released as intermediates. No degradation was found with polypropylene glycol and polypropylene glycol-containing surfactants. Two types of primary ethoxylate-degrading bacteria were isolated and characterized. Both degraded polyethylene glycols with molecular weights of 1,000 completely. Strain KoB35 fermented polyethylene glycol, ethoxyethanol, and lactate to acetate and propionate and was assigned to the described species Pelobacter propionicus. Strain KoB58 converted polyethylene glycol and many other substrates to acetate only and was assigned to the genus Acetobacterium. The pathways of anaerobic degradation of nonionic surfactants are discussed with respect to their limitations and the various groups of bacteria involved. Images PMID:3355141

  2. Complete Genome Sequence of Sphingopyxis macrogoltabida Type Strain NBRC 15033, Originally Isolated as a Polyethylene Glycol Degrader

    PubMed Central

    Nagata, Yuji; Numata, Mitsuru; Tsuchikane, Kieko; Hosoyama, Akira; Yamazoe, Atsushi; Tsuda, Masataka; Fujita, Nobuyuki; Kawai, Fusako

    2015-01-01

    Sphingopyxis macrogoltabida strain 203, the type strain of the species, grew on polyethylene glycol (PEG) and has been deposited to the stock culture at the Biological Resource Center, National Institute of Technology and Evaluation (NITE), under the number NBRC 15033. Here, we report the complete genome sequence of strain NBRC 15033. Unfortunately, genes for PEG degradation were missing. PMID:26659674

  3. Bioactivity of some chemotherapeutic agents in selected polyethylene glycol ointment bases.

    PubMed

    Farouk, A; Béla, S; Géza, R; Mohamed, S; Abdei Hadi, I

    1989-03-01

    Six different chemotherapeutic agents were individually incorporated in each of fourteen selected polyethylene glycol ointment bases, and their bioactivities were assessed using different diffusion techniques. The prepared medicated ointments were evaluated for drug release using the standard microbiological agar cup diffusion, the long period method and the short period method, as well as dialysis through artificial kidney membrane. On the basis of consistency, stability and diffusion results, formulation 11 was the most suitable base for ampicillin, formulation 14 for oxytetracycline HCl, formulation 10 and 9 for neomycin sulphate, and preparation 10 for chloramphenicol. On the basis of the results of drug release, it was evident that formulation 3 was the best for ampicillin and chloramphenicol, formulation 2 for erythromycin, formulation 4 for neomycin sulphate, formulation 12 for sulphadimidine, and formulation 14 for oxytetracycline HCl. PMID:2735193

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

    PubMed

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

    2015-09-01

    Polyethylene glycol (PEG) and related polymers are often used in the functionalization of carbon nanomaterials in procedures that involve sonication. However, PEG is very sensitive to sonolytic degradation and PEG degradation products can be toxic to mammalian cells. Thus, it is imperative to assess potential PEG degradation to ensure that the final material does not contain undocumented contaminants that can introduce artifacts into experimental results. Described here is a simple and inexpensive polyacrylamide gel electrophoresis method to detect the sonolytic degradation of PEG. The method was used to monitor the integrity of PEG phospholipid constructs and branched chain PEGs after different sonication times. This approach not only helps detect degraded PEG, but should also facilitate rapid screening of sonication parameters to find optimal conditions that minimize PEG damage. PMID:25662826

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

    SciTech Connect

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

    2014-02-12

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

  6. High-frequency fusion of Streptomyces parvulus or Streptomyces antibioticus protoplasts induced by polyethylene glycol.

    PubMed Central

    Ochi, K; Hitchcock, M J; Katz, E

    1979-01-01

    Conditions were established for the regeneration of protoplasts of Streptomyces parvulus and Streptomyces antibioticus to the mycelial form. Regeneration was accomplished with a hypertonic medium that contained sucrose, CaCl2, MgCl2, and low levels of phosphate. High-frequency fusion of protoplasts derived from auxotrophic strains of S. parvulus or S. antibioticus was induced by polyethylene glycol 4,000 (42%, wt/vol). The frequency of genetic transfer by the fusogenic procedure varied with the auxotrophic strains examined. Fusion with auxotrophic strains of S. parvulus resulted in the formation of true prototrophic recombinants. Similar studies with S. antibioticus revealed that both stable prototrophic recombinants and heterokaryons were formed. PMID:479112

  7. Evaluation of liquid chromatography column retentivity using macromolecular probes. IV. Poly(ethylene glycol) bonded phase.

    PubMed

    Berek, Dusan; Mendichi, Raniero

    2004-02-01

    Interaction properties of the novel HPLC silica gel-poly(ethylene glycol) (PEG) bonded phase were evaluated applying polymeric test substances, viz. polystyrenes, poly(methyl methacrylate)s, poly(ethylene oxide)s and poly(2-vinyl pyridine)s, and eluents of different polarities. Silanols on the silica gel surface are well shielded by the PEG phase, and silanophilic adsorption of macromolecules is suppressed in comparison with most silica C(18) bonded phases. The adsorption of solutes on the -OH groups of the PEG phase seems to be low as well. The partition of macromolecules in favor of the PEG phase is inferior to that observed in case of the silica C(18) phases. The volume of the PEG bonded phase is small and it is supposed that the PEG chains assume flat conformation on the silica gel surface. PMID:14698238

  8. [Determination of isophthalic acid in polyethylene glycol terephthalate fiber by high performance liquid chromatography].

    PubMed

    Wang, R; Wang, X Y; Tang, C J; Li, L P

    2001-07-01

    The isophthalic acid(IPA) is present in polyethylene glycol terephthalate(PET) at small level, but plays an important role for the properties of polyester fiber. Thus the PET sample was hydrolysated by 100 g/L of sodium hydrate in methanol at 70 degrees C during 10 h and finally assayed by HPLC. A reversed-phase high performance liquid chromatographic method for the separation of isophthalic acid from terephthalic acid(TPA) has been developed. The operating conditions were Novapak C18 column, methanol-water(15:85, V/V)(pH3) as mobile phase with the flow rate of 1.0 mL/min and UV detection wavelength at 254 nm. PMID:12545507

  9. Poly(ethylene glycol)-Prodrug Conjugates: Concept, Design, and Applications

    PubMed Central

    Banerjee, Shashwat S.; Aher, Naval; Patil, Rajesh; Khandare, Jayant

    2012-01-01

    Poly(ethylene glycol) (PEG) is the most widely used polymer in delivering anticancer drugs clinically. PEGylation (i.e., the covalent attachment of PEG) of peptides proteins, drugs, and bioactives is known to enhance the aqueous solubility of hydrophobic drugs, prolong circulation time, minimize nonspecific uptake, and achieve specific tumor targetability through the enhanced permeability and retention effect. Numerous PEG-based therapeutics have been developed, and several have received market approval. A vast amount of clinical experience has been gained which has helped to design PEG prodrug conjugates with improved therapeutic efficacy and reduced systemic toxicity. However, more efforts in designing PEG-based prodrug conjugates are anticipated. In light of this, the current paper highlights the synthetic advances in PEG prodrug conjugation methodologies with varied bioactive components of clinical relevance. In addition, this paper discusses FDA-approved PEGylated delivery systems, their intended clinical applications, and formulations under clinical trials. PMID:22645686

  10. Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants

    PubMed Central

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

    2013-01-01

    This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer several advantages over traditional microsphere fabrication techniques. Contrary to emulsion, suspension, and dispersion techniques, microgels formed by precipitation are of uniform shape and size, i.e. low polydispersity index, without the use of organic solvents or stabilizers. The mild conditions of the precipitation reaction, customizable properties of the microgels, and low viscosity for injections make them applicable for in vivo purposes. Unlike other fabrication techniques, microgel characteristics can be modified by changing the starting polymer molecular weight. Increasing the starting PEG molecular weight increased microgel diameter and swelling ratio. Further modifications are suggested such as encapsulating molecules during microgel crosslinking. Simple adaptations to the PEG microgel building blocks are explored for future applications of microgels as drug delivery vehicles and tissue engineering scaffolds. PMID:24378988

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

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

    2015-01-01

    Polyethylene glycol (PEG) and related polymers are often used in the functionalization of carbon nanomaterials in procedures that involve sonication. However, PEG is very sensitive to sonolytic degradation and PEG degradation products can be toxic to mammalian cells. Thus, it is imperative to assess potential PEG degradation to ensure that the final material does not contain undocumented contaminants that can introduce artifacts into experimental results. Described here is a simple and inexpensive polyacrylamide gel electrophoresis method to detect the sonolytic degradation of PEG. The method was used to monitor the integrity of PEG phospholipid constructs and branched chain PEGs after different sonication times. This approach not only helps detect degraded PEG, but should also facilitate rapid screening of sonication parameters to find optimal conditions that minimize PEG damage. PMID:25662826

  13. Investigation of the suppression effect of polyethylene glycol on copper electroplating by electrochemical impedance spectroscopy

    SciTech Connect

    Hung, C.-C.; Lee, W.-H.; Wang, Y.-L.; Chan, D.-Y.; Hwang, G.-J.

    2008-09-15

    Polyethylene glycol (PEG) is an additive that is commonly used as a suppressor in the semiconductor copper (Cu)-electroplating process. In this study, electrochemical impedance spectroscopy (EIS) was used to analyze the electrochemical behavior of PEG in the Cu-electroplating process. Polarization analysis, cyclic-voltammetry stripping, and cell voltage versus plating time were examined to clarify the suppression behavior of PEG. The equivalent circuit simulated from the EIS data shows that PEG inhibited the Cu-electroplating rate by increasing the charge-transfer resistance as well as the resistance of the adsorption layer. The presence of a large inductance demonstrated the strong adsorption of cuprous-PEG-chloride complexes on the Cu surface during the Cu-electroplating process. Increasing the PEG concentration appears to increase the resistances of charge transfer, the adsorption layer, and the inductance of the electroplating system.

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Sizing the Bacillus anthracis PA63 Channel with Nonelectrolyte Poly(Ethylene Glycols)

    PubMed Central

    Nablo, Brian J.; Halverson, Kelly M.; Robertson, Joseph W. F.; Nguyen, Tam L.; Panchal, Rekha G.; Gussio, Rick; Bavari, Sina; Krasilnikov, Oleg V.; Kasianowicz, John J.

    2008-01-01

    Nonelectrolyte polymers of poly(ethylene glycol) (PEG) were used to estimate the diameter of the ion channel formed by the Bacillus anthracis protective antigen 63 (PA63). Based on the ability of different molecular weight PEGs to partition into the pore and reduce channel conductance, the pore appears to be narrower than the one formed by Staphylococcus aureus α-hemolysin. Numerical integration of the PEG sample mass spectra and the channel conductance data were used to refine the estimate of the pore's PEG molecular mass cutoff (∼1400 g/mol). The results suggest that the limiting diameter of the PA63 pore is <2 nm, which is consistent with an all-atom model of the PA63 channel and previous experiments using large ions. PMID:18645196

  17. Polyethylene glycol-based ultrasound-assisted extraction of magnolol and honokiol from Cortex Magnoliae Officinalis.

    PubMed

    He, Lei; Fan, Tao; Hu, Jianguo; Zhang, Lijin

    2015-01-01

    In this study, a kind of green solvent named polyethylene glycol (PEG) was developed for the ultrasound-assisted extraction (UAE) of magnolol and honokiol from Cortex Magnoliae Officinalis. The effects of PEG molecular weight, PEG concentration, sample size, pH, ultrasonic power and extraction time on the extraction of magnolol and honokiol were investigated to optimise the extraction conditions. Under the optimal extraction conditions, the PEG-based UAE supplied higher extraction efficiencies of magnolol and honokiol than the ethanol-based UAE and traditional ethanol-reflux extraction. Furthermore, the correlation coefficient (R(2)), repeatability (relative standard deviation, n = 6) and recovery confirmed the validation of the proposed extraction method, which were 0.9993-0.9996, 3.1-4.6% and 92.3-106.8%, respectively. PMID:25204856

  18. Modification of macroporous silica gel with polyethylene glycol by exposure to radiation

    SciTech Connect

    Garkavenko, L.G.; Kiselev, A.V.; Nikitin, Yu.S.; Topchieva, I.N.

    1986-11-01

    Samples of KSK-1 macroporous silica gel with a surface modified by different amounts of polyethylene glycol (PEG) have been prepared by exposure to radiation. The influence of the method of coating with 20,000 PEG, the nature of the solvent used, and the radiation dose on its content in the modified samples after prolonged washing with water has been studied. The modified samples have been used to investigate the adsorption of serum albumin from aqueous solutions. The adsorption of albumin on silica gel coated with 1.2-1.5 mg/m/sup 2/ of polymer is significantly reduced in comparison with the untreated silica gel; no adsorption of protein occurs at PEG contents of > 1.6 mg/m/sup 2/.

  19. Structure of phospholipid monolayers containing poly(ethylene glycol) lipids at the air-water interface

    SciTech Connect

    Majewski, J.; Smith, G.S.; Kuhl, T.L.; Israelachvili, J.N.; Gerstenberg, M.C.

    1997-04-17

    The density distribution of a lipid monolayer at the air-water interface mixed with varying amounts of lipid with poly(ethylene glycol)polymer headgroups (polymer-lipid or PEG-lipid) was measured using neutron reflectometry. The structure of the monolayer at the interface was greatly perturbed by the presence of the bulky polymer-lipid headgroups resulting in a large increase in the thickness of the headgroup region normal to the interface and a systematic roughening of the interface with increasing polymer-lipid content. These results show how bulky hydrophilic moieties cause significant deformations and out-of-place protrusions of phospholipid monolayers and presumably bilayers, vesicles and biological membranes. In terms of polymer physics, very short polymer chains tethered to the air-water interface follow scaling behavior with a mushroom to brush transition with increasing polymer grafting density. 34 refs., 9 figs., 1 tab.

  20. Polyethylene glycol and divalent salt-induced DNA reentrant condensation revealed by single molecule measurements.

    PubMed

    Cheng, Chao; Jia, Jun-Li; Ran, Shi-Yong

    2015-05-21

    In this study, we investigated the DNA condensation induced by polyethylene glycol (PEG) with different molecular weights (PEG 600 and PEG 6000) in the presence of NaCl or MgCl2 by using magnetic tweezers (MT) and atomic force microscopy (AFM). The MT measurements show that with increasing NaCl concentration, the critical condensation force in the PEG 600-DNA or PEG 6000-DNA system increased approximately linearly. PEG 6000 solution has a larger critical force than PEG 600 solution at a given NaCl concentration. In comparison, a parabolic trend of the critical condensation force was observed with increasing MgCl2 concentration, indicating that DNA undergoes a reentrant condensation. The AFM results show that the morphologies of the compacted DNA-PEG complexes depended on the salt concentration and were consistent with the MT results. PMID:25871460

  1. Influence of polyethylene glycol on the size of Schizosaccharomyces pombe electropores

    SciTech Connect

    Hood, M.T.; Stachow, C. )

    1992-04-01

    The role of polyethylene glycol (PEG) in the transformation of Schizosaccharomyces pombe by electroporation is investigated by fluorescein isothiocyanate-dextran uptake and transformation studies. It is shown that when S. pombe cells are electroporated in the presence of PEG, the permeability state created is sustained until removal of PEG. In addition, the permeability of electroporated S. pombe envelopes is further increased with longer incubation times in PEG. The increased permeability is apparently a result of enlarged pores (electropores) due to the presence of PEG. Comparison of a heat pulse transformation protocol with electroporation suggests a second role for PEG in the uptake of macromolecules. Since pores are not thought to be created during a heat pulse, the PEG may be facilitating the uptake of plasmid DNA. This facilitation of uptake would also be expected to affect DNA uptake by electroporated cells.

  2. Poly(ethylene glycol)-polypeptide Copolymer Micelles for Therapeutic Agent Delivery.

    PubMed

    Cheng, Yilong

    2016-01-01

    Poly(ethylene glycol)-polypeptide (PEG-polypeptide) based polymeric micelles as therapeutic agent carriers have received considerable interest due to their advanced achievements in clinical trials. Polypeptides not only show well-defined secondary structure (alfa-helix and beta-sheet) and good biocompatibility, but can also be functionalized with various groups by direct N-carboxyanhydrides (NCAs) polymerization or further modification. Additionally, the ionizable side chains enable them to deliver diverse therapeutic agents, such as negative nucleic acid and positive doxorubicin. In this review, we firstly summarized the synthetic methods of amphiphilic copolymers PEG-polypeptide, and emphatically discussed recent progress on their applications as nanocarriers for therapeutic agents from following aspects: PEG-nonionic polypeptide copolymer micelles, PEG-anionic polypeptide micelles, and PEGcationic polypeptide micelles. PMID:26696015

  3. Poly(ethylene glycol) conjugated enzyme with enhanced hydrophobic compatibility for self-cleaning coatings.

    PubMed

    Zhang, Liting; Wu, Songtao; Buthe, Andreas; Zhao, Xueyan; Jia, Hongfei; Zhang, Songping; Wang, Ping

    2012-11-01

    Enzyme-based smart materials constitute a rapidly growing group of functional materials. Often the natively evolved enzymes are not compatible with hydrophobic synthetic materials, thus significantly limiting the performance of enzymes. This work investigates the use of a polyethylene glycol (PEG)-conjugated detergent enzyme for self-cleaning coatings. As a result, PEG conjugated α-amylase demonstrated a much more homogeneous distribution in polyurethane coatings than the parent native enzyme as detected by both fluorescent microscopy and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). Additionally, the conjugated enzyme showed enhanced retention in the coating and much improved thermal stability with a halflife of 20 days detected at 80 °C and over 350 days under room temperature. Such coating-incorporated enzyme afforded interesting self-cleaning functionality against starch-based stains as examined through a slipping drop test. PMID:23067105

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

    PubMed Central

    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 solubility data in mono-solvents. The obtained solubility calculation errors vary from ~ 17 % up to 35 % depend on the number of required input data. Non-linear enthalpy-entropy compensation was found for naproxen in the investigated solvent system and the Jouyban−Acree model provides reasonably accurate mathematical descriptions of the thermodynamic data of naproxen in the investigated binary solvent systems. PMID:26664370

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

    PubMed

    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

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

    PubMed

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

    2012-04-01

    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 (M(w)) PEG molecules. By use of magnetic resonance imaging, we show coating-dependent in vivo uptake in murine tumors with an optimal coating M(w) of 10,000 Da. PMID:22395568

  7. Aspiration Pneumonitis Caused by Polyethylene Glycol-Electrolyte Solution Treated with Conservative Management

    PubMed Central

    Mosquera, Ricardo A.; McDonald, Mark; Samuels, Cheryl

    2014-01-01

    Polyethylene glycol (PEG) electrolyte solution, Golytely, is an osmotic laxative commonly used in preoperative bowel cleansing. In this case report, a 9-year-old boy developed aspiration pneumonitis following accidental infusion of PEG solution into his right lung following migration of his nasogastric tube (NGT). Hypoxemia and tachypnea without respiratory failure were observed after infusion. Because PEG is a nonabsorbable toxic material, previous case reports have advocated for the performance of bronchoalveolar lavage (BAL) in the treatment of PEG pneumonitis. With close monitoring, our patient was able to be successfully treated without the need for invasive interventions including BAL or intubation. Generalizations about PEG absorption in the lung based on its permeability in the gastrointestinal tract should not deter the use of more conservative treatment in the appropriate patient. PMID:24955273

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

    PubMed

    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

  9. Physiologically based pharmacokinetic modeling of polyethylene glycol-coated polyacrylamide nanoparticles in rats.

    PubMed

    Li, Dingsheng; Johanson, Gunnar; Emond, Claude; Carlander, Ulrika; Philbert, Martin; Jolliet, Olivier

    2014-08-01

    Nanoparticles' health risks depend on their biodistribution in the body. Phagocytosis may greatly affect this distribution but has not yet explicitly accounted for in whole body pharmacokinetic models. Here, we present a physiologically based pharmacokinetic model that includes phagocytosis of nanoparticles to explore the biodistribution of intravenously injected polyethylene glycol-coated polyacrylamide nanoparticles in rats. The model explains 97% of the observed variation in nanoparticles amounts across organs. According to the model, phagocytizing cells quickly capture nanoparticles until their saturation and thereby constitute a major reservoir in richly perfused organs (spleen, liver, bone marrow, lungs, heart and kidneys), storing 83% of the nanoparticles found in these organs 120 h after injection. Key determinants of the nanoparticles biodistribution are the uptake capacities of phagocytizing cells in organs, the partitioning between tissue and blood, and the permeability between capillary blood and tissues. This framework can be extended to other types of nanoparticles by adapting these determinants. PMID:24392664

  10. Poly(ethylene glycol) diacrylate-supported ionogels with consistent capacitive behavior and tunable elastic response.

    PubMed

    Visentin, Adam F; Panzer, Matthew J

    2012-06-27

    Harnessing the many favorable properties of ionic liquids in a solid electrolyte thin film form is desirable for a host of electrical energy storage applications, including electrochemical double layer capacitors. Using a cross-linked polymer matrix to provide structural support, freestanding ionogel materials can be achieved with a wide range of polymer weight fractions. Compression testing and impedance spectroscopy have been used to characterize the mechanical and electrical responses of ionogels containing between 4.9 and 44.7 wt % poly(ethylene glycol) diacrylate. Although the elastic modulus of these solid electrolyte materials is observed to vary by more than 4 orders of magnitude within the composition range studied, concomitant changes in gel ionic conductivity and double layer capacitance were much less dramatic. PMID:22583832

  11. Mixture of cholesterol end-capped polyethylene glycol with DSPC liposomal

    NASA Astrophysics Data System (ADS)

    Sharifi, Soheil

    2015-07-01

    The dynamic of network of self-assembled liposome by end-capped polymer was investigated using dynamic light scattering. The liposome network, physically cross-linked by mixed liposome solutions with three different length scale of cholesterol end-capped polyethylene glycol. The network of liposome is dependent on both the polymer concentration and length scale. In the pure liposome, one motion at low time scale is observed by DLS. In the higher concentration of polymer in liposome, several motion is observed that the fast motion is alpha relaxation and other two slow motion are beta and gamma relaxations. The distance between diffusion coefficient of fast and slow relaxation is increased with increase of length scale of endcapped polymers. The SAXS data is fitted with a Percus-Yevick hard sphere model and it shows that the size of liposome increasing with increase of polymer length scale in the mixture system.

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

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  13. Polyethylene glycol versus sodium picosulfalte bowel preparation in the setting of a colorectal cancer screening program

    PubMed Central

    Kherad, Omar; Restellini, Sophie; Martel, Myriam; Barkun, Alan N

    2015-01-01

    BACKGROUND: Adequate bowel preparation for colonoscopy is an important predictor of colonoscopy quality. OBJECTIVE: To determine the difference in terms of effectiveness between different existing colon cleansing products in the setting of a colorectal cancer screening program. METHODS: The records of consecutive patients who underwent colonoscopy at the Montreal General Hospital (Montreal, Quebec) between April 2013 and April 2014 were retrospectively extracted from a dedicated electronic digestive endoscopic institutional database. RESULTS: Overall, 2867 charts of patients undergoing colonoscopy were assessed, of which 1130 colonoscopies were performed in a screening setting; patients had adequate bowel preparation in 90%. Quality of preparation was documented in only 61%. Bowel preparation was worse in patients receiving sodium picosulfate (PICO) alone compared with polyethylene glycol, in a screening setting (OR 0.3 [95% CI 0.2 to 0.6]). Regardless of the preparation type, the odds of achieving adequate quality cleansing was 6.6 for patients receiving a split-dose regimen (OR 6.6 [95% CI 2.1 to 21.1]). In multivariable analyses, clinical variables associated with inadequate bowel preparation in combined population were use of PICO, a nonsplit regimen and inpatient status. The polyp detection rate was very high (45.6%) and was correlated with withdrawal time. CONCLUSION: Preparation quality needs to be more consistently included in the colonoscopy report. Split-dose regimens increased the quality of colon cleansing across all types of preparations and should be the preferred method of administration. Polyethylene glycol alone provided better bowel cleansing efficacy than PICO in a screening setting but PICO remains an alternative in association with an adjuvant. PMID:26301330

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-01-01

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

  16. Polyethylene glycol modification decreases the cardiac toxicity of carbonaceous dots in mouse and zebrafish models

    PubMed Central

    Chen, Jian-tao; Sun, Hua-qin; Wang, Wei-liang; Xu, Wen-ming; He, Qin; Shen, Shun; Qian, Jun; Gao, Hui-le

    2015-01-01

    Aim: Carbonaceous dots (CDs), which have been used for diagnosis, drug delivery and gene delivery, are accumulated in heart at high concentrations. To improve their biocompatibility, polyethylene glycol-modified CDs (PEG-CDs) were prepared. In this study we compared the cardiac toxicity of CDs and PEG-CDs in mouse and zebrafish models. Methods: Mice were intravenously treated with CDs (size: 4.9 nm, 5 mg·kg−1·d−1) or PEG-CDs (size: 8.3 nm, 5 mg·kg−1·d−1) for 21 d. Their blood biochemistry indices, ECG, and histological examination were examined for evaluation of cardiac toxicity. CDs or PEG-CDs was added in incubator of cmlc2 transgenic Zebrafish embryos at 6 hpf, and the shape and size of embryos' hearts were observed at 48 hpf using a fluorescent microscope. Furthermore, whole-mount in situ hybridization was used to examine the expression of early cardiac marker gene (clml2) at 48 hpf. Results: Administration of CDs or PEG-CDs in mice caused mild, but statistically insignificant reduction in serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels detected at 7 d, which were returned to the respective control levels at 21 d. Neither CDs nor PEG-CDs caused significant changes in the morphology of heart cells. Administration of CDs, but not PEG-CDs, in mice caused marked increase of heart rate. Both CDs and PEG-CDs did not affect other ECG parameters. In the zebrafish embryos, addition of CDs (20 μg/mL) caused heart development delay, whereas addition of CDs (80 μg/mL) led to heart malformation. In contrast, PEG-CDs caused considerably small changes in heart development, which was consistent with the results from the in situ hybridization experiments. Conclusion: CDs causes greater cardiac toxicity, especially regarding heart development. Polyethylene glycol modification can attenuate the cardiac toxicity of CDs. PMID:26456589

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

    PubMed

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

    2016-05-01

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

  18. Improving of bowel cleansing effect for polyethylene glycol with ascorbic acid using simethicone

    PubMed Central

    Yoo, In Kyung; Jeen, Yoon Tae; Kang, Seung Hun; Lee, Jae Hyung; Kim, Seung Han; Lee, Jae Min; Choi, Hyuk Soon; Kim, Eun Sun; Keum, Bora; Chun, Hoon Jai; Lee, Hong Sik; Kim, Chang Duck

    2016-01-01

    Abstract Background and Aim: Low-volume polyethylene glycol with ascorbic acid (PEG-Asc) use is reported to be as safe and effective as traditional 4-L polyethylene glycol use. However, PEG-Asc produces bubbles, which cause problems during colonoscopy. Data on the effects of using antifoaming agents such as simethicone with PEG-Asc are lacking. The aim of this CONSORT-prospective, randomized, observer-blinded, controlled trial is to compare the quality of bowel preparation and compliance between PEG-Asc users and PEG-Asc plus simethicone users. Methods: Adult outpatients aged 18 to 80 years undergoing colonoscopy were recruited to the study. Two hundred sixty patients were randomly assigned to 1 of 2 treatment arms, PEG-Asc or PEG-Asc plus simethicone. The primary outcome measure was the bowel cleansing quality using Boston bowel preparation scale and bubble scores. The secondary outcome measures were patient tolerability and doctor tolerability. Results: The simethicone group showed superior cleansing results (6–9 Boston scale scores: 99% vs. 84%, <5% bubble scores: 96% vs. 49%, P < 0.001) and fewer gastrointestinal symptoms (abdominal fullness: 24% vs. 55%, colicky pain: 5% vs. 24%, P < 0.001) than the non-simethicone group. Moreover, endoscopist fatigue during colonoscopy was lower in the simethicone group than in the non-simethicone group (1.31 ± 0.75 vs. 2.97 ± 2.14, P < 0.001). Conclusion: PEG-Asc plus simethicone use was more effective and associated with better patient and endoscopist tolerance than PEG-Asc use. Therefore, this combination is recommended as one of the promising methods for bowel preparation before colonoscopy. PMID:27428209

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

    NASA Astrophysics Data System (ADS)

    Du, Ruikui; Gao, Baojiao; Li, Yanbin

    2013-06-01

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

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Mechanics of semiflexible chains formed by poly(ethylene glycol)-linked paramagnetic particles.

    PubMed

    Biswal, Sibani Lisa; Gast, Alice P

    2003-08-01

    Magnetorheological particles, permanently linked into chains, provide a magnetically actuated means to manipulate microscopic fluid flow. Paramagnetic colloidal particles form reversible chains by acquiring dipole moments in the presence of an external magnetic field. By chemically connecting paramagnetic colloidal particles, flexible magnetoresponsive chains can be created. We link the paramagnetic microspheres using streptavidin-biotin binding. Streptavidin coated microspheres are placed in a flow cell and a magnetic field is applied, causing the particles to form chains. Then a solution of polymeric linkers of bis-biotin-poly(ethylene glycol) molecules is added in the presence of the field. These linked chains remain responsive to a magnetic field; however, in the absence of an external magnetic field these chains bend and flex due to thermal motion. The chain flexibility is determined by the length of the spacer molecule between particles and is quantified by the flexural rigidity or bending stiffness. To understand the mechanical properties of the chains, we use a variety of optical trapping experiments to measure the flexural rigidity. Increasing the length of the poly(ethylene glycol) chain in the linker increases the flexibility of the chains. PMID:14524968

  3. Polyethylene glycol binding alters human telomere G-quadruplex structure by conformational selection

    PubMed Central

    Buscaglia, Robert; Miller, M. Clarke; Dean, William L.; Gray, Robert D.; Lane, Andrew N.; Trent, John O.; Chaires, Jonathan B.

    2013-01-01

    Polyethylene glycols (PEGs) are widely used to perturb the conformations of nucleic acids, including G-quadruplexes. The mechanism by which PEG alters G-quadruplex conformation is poorly understood. We describe here studies designed to determine how PEG and other co-solutes affect the conformation of the human telomeric quadruplex. Osmotic stress studies using acetonitrile and ethylene glycol show that conversion of the ‘hybrid’ conformation to an all-parallel ‘propeller’ conformation is accompanied by the release of about 17 water molecules per quadruplex and is energetically unfavorable in pure aqueous solutions. Sedimentation velocity experiments show that the propeller form is hydrodynamically larger than hybrid forms, ruling out a crowding mechanism for the conversion by PEG. PEGs do not alter water activity sufficiently to perturb quadruplex hydration by osmotic stress. PEG titration experiments are most consistent with a conformational selection mechanism in which PEG binds more strongly to the propeller conformation, and binding is coupled to the conformational transition between forms. Molecular dynamics simulations show that PEG binding to the propeller form is sterically feasible and energetically favorable. We conclude that PEG does not act by crowding and is a poor mimic of the intranuclear environment, keeping open the question of the physiologically relevant quadruplex conformation. PMID:23804761

  4. Controlling microencapsulation and release of micronized proteins using poly(ethylene glycol) and electrospraying.

    PubMed

    Bock, Nathalie; Dargaville, Tim R; Woodruff, Maria A

    2014-07-01

    The fabrication of tailored microparticles for delivery of therapeutics is a challenge relying upon a complex interplay between processing parameters and materials properties. The emerging use of electrospraying allows better tailoring of particle morphologies and sizes than current techniques, critical to reproducible release profiles. While dry encapsulation of proteins is essential for the release of active therapeutics from microparticles, it is currently uncharacterized in electrospraying. To this end, poly(ethylene glycol) (PEG) was assessed as a micronizing and solubilizing agent for dry protein encapsulation and release from electrosprayed particles made from polycaprolactone (PCL). The physical effect of PEG in protein-loaded poly(lactic-co-glycolic acid) (PLGA) particles was also studied, for comparison. The addition of 5-15 wt% PEG 6 kDa or 35 kDa resulted in reduced PCL particle sizes and broadened distributions, which could be improved by tailoring the electrospraying processing parameters, namely by reducing polymer concentration and increasing flow rate. Upon micronization, protein particle size was reduced to the micrometer domain, resulting in homogenous encapsulation in electrosprayed PCL microparticles. Microparticle size distributions were shown to be the most determinant factor for protein release by diffusion and allowed specific control of release patterns. PMID:24657821

  5. The characterization of dendronized poly(ethylene glycol)s and poly(ethylene glycol) multi-arm stars using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    PubMed

    Myers, Brittany K; Zhang, Boyu; Lapucha, Joanna E; Grayson, Scott M

    2014-01-15

    The synthesis of branched poly(ethylene glycol) (PEG) derivatives, namely star PEG and dendronized PEG, can be challenging and their purity can be difficult to ascertain using traditional techniques, such as NMR and GPC. Herein, the detailed characterization of these branched PEGs using MALDI-ToF MS was investigated in order to confirm their structural purity. In this light, mass spectrometry offers a number of advantages for polymer characterization, including the ability to get detailed structural data, such as end group masses, from microgram-scale samples. In addition, the ability to rapidly acquire data from crude reaction aliquots makes MALDI-ToF MS ideal for monitoring end group transformations. PMID:24370103

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

    NASA Astrophysics Data System (ADS)

    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

  7. Polyvinyl alcohol-graft-polyethylene glycol hydrogels improve utility and biofunctionality of injectable collagen biomaterials.

    PubMed

    Hartwell, Ryan; Chan, Ben; Elliott, Keenan; Alnojeidi, Hatem; Ghahary, Aziz

    2016-01-01

    Collagen-based materials have become a staple in both research and the clinic. In wound care, collagen-based materials comprise a core gamut of biological dressings and therapeutic strategies. In research, collagen-based materials are employed in everything from 3D cultures to bioprinting. Soluble collagen is well characterized to undergo fibrillation at neutral pH and 37 °C. To remain stable, a neutralized collagen solution must be maintained at 4 °C. These physical characteristics of collagen impose limitations on its utility. In our previous work, we identified that the incorporation of a simple polyvinyl alcohol:borate hydrogel could improve the rate of collagen gel fibrillation. In this work we sought to further investigate the interactions of polyvinyl alcohol blend variants, as surfactant-like polymers, in comparison with known non-polymer surfactants. To conduct our investigations scaffold variants were created using increasing concentrations of polyvinyl alcohol, differing combinations of polymers, and non-polymer surfactants Tweens 20 and 80, and TritonX-100. Activation energy for collagen fibrillation was found to significantly decrease in the presence of polyvinyl alcohols (p  <  0.01) at and above 0.4%w/v concentration. Further, addition of polyvinyl alcohol-graft-polyethylene glycol had the greatest enhancement (2.02 fold) on the fibrillation kinetics (p  <  0.01), wetting properties and the stability of the collagen scaffolds post-freeze drying. Our results demonstrated that the addition of polyvinyl alcohol hydrogels to a collagen solution could stabilize collagen solution such that the solution could easily be lyophilized (at pH 7) and then reconstituted with water. Cells cultured in polyvinyl alcohol scaffolds also exhibited more organized F-actin, as well as a reduced abundance of pro-collagen and α-smooth actin. In conclusion, our results demonstrate for the first time that polyvinyl alcohol, preferably polyvinyl alcohol-graft-polyethylene

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

    NASA Astrophysics Data System (ADS)

    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

  9. Synthesis, characterization and cytotoxicity of poly(ethylene glycol)-graft-trimethyl chitosan block copolymers.

    PubMed

    Mao, Shirui; Shuai, Xintao; Unger, Florian; Wittmar, Matthias; Xie, Xiulan; Kissel, Thomas

    2005-11-01

    PEGylated trimethyl chitosan (TMC) copolymers were synthesized in an attempt to both increase the solubility of chitosan in water, and improve the biocompatibility of TMC. A series of copolymers with different degrees of substitution were obtained by grafting activated poly(ethylene glycol)s (PEG) of different MW onto TMC via primary amino groups. Structure of the copolymers was characterized using 1H, 13C NMR spectroscopy and GPC. Solubility experiments demonstrated that PEG-g-TMC copolymers were completely water-soluble over the entire pH range of 1-14 regardless of the PEG MW, even when the graft density was as low as 10%. Using the methyl tetrazolium (MTT) assay, the effect of TMC molecular weight, PEGylation ratio, PEG and TMC molecular weight in the copolymers, and complexation with insulin on the cytotoxicity of TMC was examined, and IC50 values were calculated with L929 cell line. All polymers exhibited a time- and dose-dependent cytotoxic response that increased with molecular weight. PEGylation can decrease the cytotoxicity of TMC to a great extent in the case of low molecular weight TMCs. According to the cytotoxicity results, PEG 5 kDa is superior for PEGylation when compared to PEG 550 Da at similar graft ratios. Complexation with insulin further increased cell viability. In addition, Lactate dehydrogenase (LDH) assays were performed to quantify the membrane-damaging effects of the copolymers, which is in line with the conclusion drawn from MTT assay. Moreover, the safety of the copolymers was corroborated by observing the morphological change of the cells with inverted phase contrast microscopy. Based upon these results PEG-g-TMC merits further investigations as a drug delivery vehicle. PMID:15913769

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

    PubMed

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

    2013-10-28

    In this work, the thermal stabilities of a series of polyethylene glycols (PEG 4000, 6000 and 10000) were investigated after compositing with different kinds of inorganic salts, such as ammonium molybdate tetrahydrate (AMT), NH4VO3, (NH4)2SO4, NH4NO3, Na2SO4, Na2MoO4. It was first observed that all the ammonium salts exerted leveling effects for the thermal stabilities of the PEGs. In other words, the presence of the ammonium salts caused the occurrence of the maximum decomposition rates of the PEGs with the same repeat sequence but different chain lengths at almost the same temperatures. Leveling effects were defined by three parameters: leveling spans, leveling degrees and dispersion degrees of leveling. Further experiments revealed that leveling effects also occur in similar types of polymers: polypropylene glycols (PPG 2000, 3000 and 4000). A series of independent experiments including Fourier transformation infrared spectroscopy, Raman spectroscopy, differential scanning calorimetry, time-of-flight mass spectrometry, conductivity and field-emission scanning electron microscopy were performed to explore the origin of leveling effects. We consider that the interaction between inorganic ions and polymer molecules and the Hofmeister effect of ions in solution are two important factors affecting the stability of salt–polymer composites, because they can contribute to decrease the interaction between the polymer chains, leading to changes in the conformation and pyrolysis mode of polymers. We believe that the finding of leveling effects would be significant for both basic and applied research of soft matter. PMID:26029781

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

    PubMed Central

    Taché, Sylviane; Parnaud, Géraldine; Van Beek, Erik; Corpet, Denis E.

    2006-01-01

    Background Polyethylene glycol (PEG), an osmotic laxative, is a very potent inhibitor of colon cancer in rats. In a search for mechanisms, we tested the hypothesis that fecal bulking and moisture decreases colon carcinogenesis. We also looked for PEG effects on crypt cells in vivo. Methods Fischer 344 rats (N=272) were given an injection of the colon carcinogen azoxymethane. They were then randomized to a standard AIN76 diet containing one of 19 laxative agents (5% w/w in most cases): PEG 8000 and other PEG-like compounds, carboxymethylcellulose, polyvinylpyrrolidone, sodium polyacrylate, calcium polycarbophil, karaya gum, psyllium, mannitol, sorbitol, lactulose, propylene glycol, magnesium hydroxide, sodium phosphate, bisacodyl, docusate, and paraffin oil. Aberrant crypt foci (ACF) and fecal values were measured blindly after a 30-day treatment. Proliferation, apoptosis, and the removal of cells from crypts were studied in control and PEG-fed rats by various methods, including TUNEL and fluorescein dextran labeling. Results PEG 8000 reduced nine-fold the number of ACF in rats (p<0.001). The other PEGs and magnesium-hydroxide modestly suppressed ACF, but not the other laxatives. ACF number did not correlate with fecal weight or moisture. PEG doubled the apoptotic bodies per crypt (p<0.05), increased proliferation by 25–50% (p<0.05) and strikingly increased (>40-fold) a fecal marker of epitheliolysis in the gut (p<0.001). PEG normalized the percentage of fluorescein dextran labeled cells on the top of ACF (p<0.001). Conclusions Among laxatives, only PEG afforded potent chemoprevention. PEG protection was not due to increased fecal bulking, but likely to the elimination of cells from precancerous lesions. PMID:16716974

  12. Volume and dielectric properties of cesium perchlorate and its solubility in aqueous solutions of polyethylene glycol-600

    NASA Astrophysics Data System (ADS)

    Yukhno, G. D.; Krasnoperova, A. P.

    2013-12-01

    The dependences of density and static dielectric permeability of water solutions of polyethylene glycol-600 on temperature and polyglycol concentration are studied. It is found that the maximum in the dependences of dielectric permeability on solvent composition is due to intermolecular interactions between water and polyglycol, resulting in the formation of oxonium compounds. The solubility of cesium perchlorate CsClO4 in a water-polyethylene glycol-600 system is investigated using radioactive indicators with 137Cs isotopes over the range of concentrations of mixed solvents at temperatures ranging from 278.15 to 318.15 K. Thermodynamic characteristics of CsClO4 dissolution in mixed solvents are also calculated and analyzed.

  13. Extraction of americium in different oxidation states in a two-phase aqueous system based on poly(ethylene glycol)

    SciTech Connect

    Molochnikova, N.P.; Frenkel', B.F.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-09-01

    The extraction of americium in different states of oxidation was studied in a two-phase aqueous system based on poly(ethylene glycol). Conditions were found for the quantitative extraction of americium (III) and americium (V) from solutions of ammonium sulfate in the pH range of 3-5 and in the presence of arsenazo III. The composition of the complexes of americium with the reagent was determined; americium (III) reacts with arsenazo III in solutions of ammonium sulfate to form complexes with the composition of MeR and Me/sub 2/R. Characteristics of the absorption spectra of complexes of americium (III) and (V) with arsenazo III in ammonium sulfate solutions and in extracts based on aqueous solutions of poly(ethylene glycol) were found. The molar extinction coefficients of complexes of americium with arsenazo III were determined in these solutions.

  14. Molecular structure of a water-polyethylene glycol-KOH system, according to densitometry and viscometry data

    NASA Astrophysics Data System (ADS)

    Masimov, E. A.; Pashayev, B. G.; Hasanov, H. Sh.; Musayeva, S. I.

    2013-12-01

    The dynamic viscosity and density of a water-polyethylene glycol-KOH system are measured at temperatures of 293.15 to 323.15 K in concentrations ranging from 0.00001 and 0.001 (mole fractions). The activation parameters of viscous flow (Δ G {η/≠}, Δ H {η/≠}, and Δ S {η/≠}), structural temperature ( T 0), the partial molar volume of polyethylene glycol (PEG) in solution , intrinsic viscosity([η]), and the Huggins constant ( K H), are calculated. It is found that PEG has a structuring effect on water in water-PEG and water-PEG-KOH systems, with the PEG structuring effect in the latter being somewhat attenuated by the destructuring influence of KOH.

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

    PubMed Central

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

    2013-01-01

    Strategies to encapsulate cells in cytocompatible 3-dimensional hydrogels with tunable mechanical properties and degradability without harmful gelling conditions are highly desired for regenerative medicine applications. Here we reported a method for preparing poly(ethylene glycol)-co-polycarbonate hydrogels through copper-free, strain-promoted azide-alkyne cycloaddition (SPAAC) “Click” chemistry. Hydrogels with varying mechanical properties were formed by “clicking” azido-functionalized poly(ethylene glycol)-co-polycarbonate macromers with dibenzocyclooctyne functionalized poly(ethylene glycol) under physiological conditions within minutes. Bone marrow stromal cells encapsulated in these gels exhibited higher cellular viability than those encapsulated in photo-crosslinked poly(ethylene glycol) dimethacrylate. The precise control over the macromer compositions, the cytocompatible SPAAC crosslinking, and the degradability of the polycarbonate segments combined make these hydrogels promising candidates for scaffold- and stem cell-assisted tissue repair and regeneration. PMID:21954076

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  17. A new synthesis of lamellar-mesostructured silica by using poly(ethylene glycol) distearate as template

    SciTech Connect

    Zhang Huanzhi; Jin Zhengwei; Wang Xiaodong

    2008-11-03

    A lamellar-mesostructured silica has been synthesized by using poly(ethylene glycol) distearate as template in ethanol solution. Highly ordered lamellar mesostructure was confirmed by X-ray diffraction pattern, transmission electronic microscopy, and nitrogen adsorption-desorption isotherm. The material obtained in this work has a large interlayer distance, and good thermal and mechanical stabilities, which can favor the preparation of the in situ polymerized nanocomposites based on intercalation of polymers in the lamellar-mesostructured silica.

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

    PubMed

    Walsh, J L; Knull, H R

    1988-01-01

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

  19. Poly(ethylene glycol)-grafted copolymers as synthetic equivalents of benzyltriethylammonium chloride for triphase catalytic alkylation

    SciTech Connect

    Kimura, Y.; Kirszensztejn, P.; Regan, S.L.

    1983-02-11

    Synthetic results are reported, which show that simple poly(ethylene glycols) grafted to cross-linked polystyrene are remarkably active and stable triphase catalysts for the alkylation of nitriles, ketones, and alcohols. Resins were prepared from commercial chloromethylated polystyrene by using standard grafting procedures. For comparison of their efficacies for promoting alkylation, the conversion of phenylacetonitrile to 2-phenylhexane-nitrile was chosen as a standard reaction.

  20. Aqueous Biphasic Systems Based on Salting-Out Polyethylene Glycol or Ionic Solutions: Strategies for Actinide or Fission Product Separations

    SciTech Connect

    Rogers, Robin D.; Gutowski, Keith E.; Griffin, Scott T.; Holbrey, John D.

    2004-03-29

    Aqueous biphasic systems can be formed by salting-out (with kosmotropic, waterstructuring salts) water soluble polymers (e.g., polyethylene glycol) or aqueous solutions of a wide range of hydrophilic ionic liquids based on imidazolium, pyridinium, phosphonium and ammonium cations. The use of these novel liquid/liquid biphases for separation of actinides or other fission products associated with nuclear wastes (e.g., pertechnetate salts) has been demonstrated and will be described in this presentation.

  1. Physical and rheological characterisation of polyethylene glycol-cashew-nut tree gum aqueous two-phase systems.

    PubMed

    Oliveira, L A; Sarubbo, L A; Porto, A L F; Lima-Filho, J L; Campos-Takaki, G M; Tambourgi, E B

    2002-01-01

    The characterisation of the polyethylene glycol-cashew-nut tree gum aqueous two-phase system is described. Factors which affect the phase diagram including polymer molecular mass, pH and temperature were analysed. The physico-chemical properties of the system such as density, viscosity, volume ratio and phase separation times were also described. The characteristics of the system studied indicate it to be very attractive as a separation technique. PMID:11824395

  2. Rationalization of Membrane Protein Crystallization with Polyethylene Glycol Using a Simple Depletion Model

    PubMed Central

    Tanaka, Shinpei; Ataka, Mitsuo; Onuma, Kazuo; Kubota, Tomomi

    2003-01-01

    Based on the importance of crystallizing membrane proteins in a rational way, cytochrome bc1 complex (BC1) was crystallized using polyethylene glycol (PEG) as a sole crystallization agent. Interaction between protein-detergent complexes of BC1 was estimated by dynamic light scattering, and was compared with the numerical calculation using the Derjaguin-Landau-Verwey-Overbeek potential plus a depletion potential, without considering specific surface properties of the protein-detergent complexes. The experiments and calculation were found to be consistent and we obtained a relation between PEG molecular weight M and the range of depletion zone δ as δ ∼ M0.48±0.02. The stability of liquid phase of BC1 solutions was controlled by a ratio of (the range of depletion zone)/(the radius of a BC1 particle), which was consistent with recent theoretical predictions. The crystallization was most successful under a condition where the stability of the liquid phase changed from stable to unstable. The PEG molecular weight that fulfilled this condition coincided with the one used empirically to crystallize BC1 in the past by a number of groups. These results are compared to the fact that membrane proteins were often successfully crystallized close to the detergent cloud point. PMID:12719259

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

    PubMed

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

    2004-08-01

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

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

    PubMed

    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  <  0.01) in 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  <  0.01) and sox-9 (p  <  0.01) were found in 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

  5. Polyethylene glycol rinse solution: An effective way to prevent ischemia-reperfusion injury

    PubMed Central

    Zaouali, Mohamed Amine; Bejaoui, Mohamed; Calvo, Maria; Folch-Puy, Emma; Pantazi, Eirini; Pasut, Gianfranco; Rimola, Antoni; Ben Abdennebi, Hassen; Adam, René; Roselló-Catafau, Joan

    2014-01-01

    AIM: To test whether a new rinse solution containing polyethylene glycol 35 (PEG-35) could prevent ischemia-reperfusion injury (IRI) in liver grafts. METHODS: Sprague-Dawley rat livers were stored in University of Wisconsin preservation solution and then washed with different rinse solutions (Ringer’s lactate solution and a new rinse solution enriched with PEG-35 at either 1 or 5 g/L) before ex vivo perfusion with Krebs-Heinseleit buffer solution. We assessed the following: liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity), liver function (bile output and vascular resistance), oxidative stress (malondialdehyde), nitric oxide, liver autophagy (Beclin-1 and LCB3) and cytoskeleton integrity (filament and globular actin fraction); as well as levels of metalloproteinases (MMP2 and MMP9), adenosine monophosphate-activated protein kinase (AMPK), heat shock protein 70 (HSP70) and heme oxygenase 1 (HO-1). RESULTS: When we used the PEG-35 rinse solution, reduced hepatic injury and improved liver function were noted after reperfusion. The PEG-35 rinse solution prevented oxidative stress, mitochondrial damage, and liver autophagy. Further, it increased the expression of cytoprotective heat shock proteins such as HO-1 and HSP70, activated AMPK, and contributed to the restoration of cytoskeleton integrity after IRI. CONCLUSION: Using the rinse solution containing PEG-35 was effective for decreasing liver graft vulnerability to IRI. PMID:25473175

  6. Synthesis and Characterization of a Poly(ethylene glycol)-Poly(simvastatin) Diblock Copolymer

    PubMed Central

    Asafo-Adjei, Theodora A.; Dziubla, Thomas D.; Puleo, David A.

    2014-01-01

    Biodegradable polyesters are commonly used as drug delivery vehicles, but their role is typically passive, and encapsulation approaches have limited drug payload. An alternative drug delivery method is to polymerize the active agent or its precursor into a degradable polymer. The prodrug simvastatin contains a lactone ring that lends itself to ring-opening polymerization (ROP). Consequently, simvastatin polymerization was initiated with 5 kDa monomethyl ether poly(ethylene glycol) (mPEG) and catalyzed via stannous octoate. Melt condensation reactions produced a 9.5 kDa copolymer with a polydispersity index of 1.1 at 150 °C up to a 75 kDa copolymer with an index of 6.9 at 250 °C. Kinetic analysis revealed first-order propagation rates. Infrared spectroscopy of the copolymer showed carboxylic and methyl ether stretches unique to simvastatin and mPEG, respectively. Slow degradation was demonstrated in neutral and alkaline conditions. Lastly, simvastatin, simvastatin-incorporated molecules, and mPEG were identified as the degradation products released. The present results show the potential of using ROP to polymerize lactone-containing drugs such as simvastatin. PMID:25431653

  7. Protein adsorption to polyethylene glycol modified liposomes from fibrinogen solution and from plasma.

    PubMed

    Price, M E; Cornelius, R M; Brash, J L

    2001-06-01

    Unmodified and polyethylene glycol (PEG) modified neutral and negatively charged liposomes were prepared by freeze-thaw and extrusion followed by chromatographic purification. The effects of PEG molecular weight (PEG 550, 2000, 5000), PEG loading (0-15 mol%), and liposome surface charge on fibrinogen adsorption were quantified using radiolabeling techniques. All adsorption isotherms increased monotonically over the concentration range 0-3 mg/ml and adsorption levels were low. Negatively charged liposomes adsorbed significantly more fibrinogen than neutral liposomes. PEG modification had no effect on fibrinogen adsorption to neutral liposomes. An inverse relationship was found between PEG loading of negatively charged liposomes and fibrinogen adsorption. PEGs of all three molecular weights at a loading of 5 mol% reduced fibrinogen adsorption to negatively charged liposomes. Protein adsorption from diluted plasma (10% normal strength) to four different liposome types (neutral, PEG-neutral, negatively charged, and PEG-negatively charged) was investigated using gel electrophoresis and immunoblotting. The profiles of adsorbed proteins were similar on all four liposome types, but distinctly different from the profile of plasma itself, indicating a partitioning effect of the lipid surfaces. alpha2-macroglobulin and fibronectin were significantly enriched on the liposomes whereas albumin, transferrin, and fibrinogen were depleted compared to plasma. Apolipoprotein AI was a major component of the adsorbed protein layers. The blot of complement protein C3 adsorbed on the liposomes suggested that the complement system was activated. PMID:11406096

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

    PubMed

    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

  9. Prevention of peritendinous adhesions with electrospun polyethylene glycol/polycaprolactone nanofibrous membranes.

    PubMed

    Chen, Chih-Hao; Chen, Shih-Hsien; Shalumon, K T; Chen, Jyh-Ping

    2015-09-01

    Postoperative adhesion formation is the major complication that could occur after acute tendon surgery. The application of an anti-adhesive membrane at the post-surgical site is deemed as a potential way to solve this problem by preventing adhesive fibrotic tissue development. In this study, we fabricated electrospun composite poly(ethylene glycol) (PEG)/poly(caprolactone) (PCL) nanofibrous membrane (NFM) to prevent peritendinous adhesions, which could act as a barrier between the tendon and surrounding tissues, without interrupting mass transfer and normal tendon gliding. PCL/PEG NFMs of 0% PEG (PCL), 25% PEG (25PECL), 50% PEG (50PECL) and 75% PEG (75PECL) were prepared and characterized for physico-chemical properties. The PCL NFM shows the lowest protein permeability while 25PECL NFM exhibited the largest fiber diameter, smallest pore size and the largest ultimate stress and strain. The 75PECL NFM had the lowest water contact angle and the highest Young's modulus. In vitro cell adhesion and migration experiments with fibroblasts indicate that all NFMs could prevent cell penetration, with 75PECL NFM having the least cell attachment. In vivo application of 75PECL NFM on the repaired site of rabbit flexor tendon rupture model demonstrated improved efficacy compared with the PCL NFM and a commercial anti-adhesion barrier (Seprafilm™), from gross observation, histological analysis and functional assays. We concluded that 75PECL NFM could function as an effective anti-adhesion membrane after tendon surgery in a clinical setting. PMID:26115533

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

    PubMed

    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

  11. Controlling Affinity Binding with Peptide-Functionalized Poly(ethylene glycol) Hydrogels**

    PubMed Central

    Lin, Chien-Chi; Anseth, Kristi S.

    2009-01-01

    Poly(ethylene glycol) (PEG) hydrogels functionalized with peptide moieties have been widely used in regenerative medicine applications. While many studies have suggested the importance of affinity binding within PEG hydrogels, the relationships between the structures of the peptide motifs and their binding to protein therapeutics remain largely unexplored, especially in the recently developed thiol-acrylate photopolymerization systems. Herein, we employ Förster resonance energy transfer (FRET) and thiol-acrylate photopolymerizations to investigate how the architectures of affinity peptides in crosslinked hydrogels affect their binding to diffusible proteins. The binding between diffusible streptavidin and biotinylated peptide immobilized to PEG hydrogel network was used as a model system to reveal the interplay between affinity binding and peptide sequences/architectures. In addition, we design peptides with different structures to enhance affinity binding within PEG hydrogels and to provide tunable affinity-based controlled delivery of basic fibroblast growth factor (bFGF). This study demonstrates the importance of affinity binding in controlling the availability of hydrogel-encapsulated proteins and provides strategies for enhancing affinity binding of protein therapeutics to bound peptide moieties in thiol-acrylate photopolymerized PEG hydrogels. The results presented herein should find useful on the design and fabrication of hydrogels to retain and sustained release of growth factors for promoting tissue regeneration. PMID:20148198

  12. Poly(propylene fumarate)/Polyethylene Glycol-Modified Graphene Oxide Nanocomposites for Tissue Engineering.

    PubMed

    Díez-Pascual, Ana M; Díez-Vicente, Angel L

    2016-07-20

    Poly(propylene fumarate) (PPF)-based nanocomposites incorporating different amounts of polyethylene glycol-functionalized graphene oxide (PEG-GO) have been prepared via sonication and thermal curing, and their surface morphology, structure, thermal stability, hydrophilicity, water absorption, biodegradation, cytotoxicity, mechanical, viscoelastic and antibacterial properties have been investigated. SEM and TEM images corroborated that the noncovalent functionalization with PEG caused the exfoliation of GO into thinner flakes. IR spectra suggested the presence of strong hydrogen-bonding interactions between the nanocomposite components. A gradual rise in the level of hydrophilicity, water uptake, biodegradation rate, surface roughness, protein absorption capability and thermal stability was found upon increasing GO concentration in the composites. Tensile tests revealed improved stiffness, strength and toughness for the composites compared to unfilled PPF, ascribed to a homogeneous GO dispersion within the matrix along with a strong PPF/PEG-GO interfacial adhesion via polar and hydrogen bonding interactions. Further, the nanocomposites retained enough stiffness and strength under a biological state to provide effective support for bone tissue formation. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus and Staphylococcus epidermidis as well as Gram-negative Pseudomonas aeruginosa and Escherichia coli microorganisms, and it rose sharply upon increasing GO concentration; systematically, the biocide effect was stronger versus Gram-positive bacteria. Cell viability data demonstrated that PPF/PEG-GO composites do not induce toxicity over human dermal fibroblasts. These novel materials show great potential to be applied in the bone tissue engineering field. PMID:27383639

  13. Properties of polyethylene glycol/cyclodextrin hydrogels revealed by spin probes and spin labelling methods.

    PubMed

    Ionita, Gabriela; Ariciu, Ana Maria; Turcu, Ioana Maria; Chechik, Victor

    2014-03-21

    The properties of a gel consisting of a covalent network formed by the reaction of isocyanate end-capped polyethylene glycol (PEG) with β-cyclodextrin, were investigated by EPR spectroscopy. Spin-labelled cyclodextrin was incorporated into the cross-link points of the gel and at the chain ends. The dynamics of the gel fibres as reported by the spin label, was found to be sensitive to the H-bonding ability of the solvent, density of cross-links and temperature. Addition of spin probes (e.g., TEMPO and adamantane-TEMPO) to the unlabelled gel made it possible to characterise the solvent pools in the gel. While TEMPO was uniformly distributed throughout the solvent pools, the adamantane derivative was located at the gel fibre-solvent pool interface; these two probes thus reported on the different locations in the solvent pools. At low temperature, the gels were shown to prevent ice crystallisation in the solvent pools resulting in the formation of supercooled water. Both probes showed that the water froze at ca. 250 K, thus suggesting that the properties of the supercooled water are uniform across the solvent pools. PMID:24651650

  14. Protective Effect of Intravenous High Molecular Weight Polyethylene Glycol on Fatty Liver Preservation

    PubMed Central

    Bejaoui, Mohamed; Pantazi, Eirini; Folch-Puy, Emma; Panisello, Arnau; Calvo, María; Pasut, Gianfranco; Rimola, Antoni; Navasa, Miquel; Adam, René; Roselló-Catafau, Joan

    2015-01-01

    Ischemia reperfusion injury (IRI) leads to significant tissue damage in liver surgery. Polyethylene glycols (PEGs) are water soluble nontoxic polymers that have proved their effectiveness against IRI. The objective of our study was to investigate the potential protective effects of intravenous administration of a high molecular weight PEG of 35 kDa (PEG 35) in steatotic livers subjected to cold ischemia reperfusion. In this study, we used isolated perfused rat liver model to assess the effects of PEG 35 intravenous administration after prolonged cold ischemia (24 h, 4°C) and after reperfusion (2 h, 37°C). Liver injury was measured by transaminases levels and mitochondrial damage was determined by confocal microscopy assessing mitochondrial polarization (after cold storage) and by measuring glutamate dehydrogenase activity (after reperfusion). Also, cell signaling pathways involved in the physiopathology of IRI were assessed by western blot technique. Our results show that intravenous administration of PEG 35 at 10 mg/kg ameliorated liver injury and protected the mitochondria. Moreover, PEG 35 administration induced a significant phosphorylation of prosurvival protein kinase B (Akt) and activation of cytoprotective factors e-NOS and AMPK. In conclusion, intravenous PEG 35 efficiently protects steatotic livers exposed to cold IRI. PMID:26543868

  15. Hybrid Atomistic and Coarse-Grained Molecular Dynamics Simulations of Polyethylene Glycol (PEG) in Explicit Water.

    PubMed

    Stanzione, Francesca; Jayaraman, Arthi

    2016-05-01

    In-silico design of polymeric biomaterials requires molecular dynamics (MD) simulations that retain essential atomistic/molecular details (e.g., explicit water around the biofunctional macromolecule) while simultaneously achieving large length and time scales pertinent to macroscale function. Such large-scale atomistically detailed macromolecular MD simulations with explicit solvent representation are computationally expensive. One way to overcome this limitation is to use an adaptive resolution scheme (AdResS) in which the explicit solvent molecules dynamically adopt either atomistic or coarse-grained resolution depending on their location (e.g., near or far from the macromolecule) in the system. In this study we present the feasibility and the limitations of AdResS methodology for studying polyethylene glycol (PEG) in adaptive resolution water, for varying PEG length and architecture. We first validate the AdResS methodology for such systems, by comparing PEG and solvent structure with that from all-atom simulations. We elucidate the role of the atomistic zone size and the need for calculating thermodynamic force correction within this AdResS approach to correctly reproduce the structure of PEG and water. Lastly, by varying the PEG length and architecture, we study the hydration of PEG, and the effect of PEG architectures on the structural properties of water. Changing the architecture of PEG from linear to multiarm star, we observe reduction in the solvent accessible surface area of the PEG, and an increase in the order of water molecules in the hydration shells. PMID:27108869

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

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

    2016-09-01

    Clinicians commonly encounter dysphagia and constipation in a skilled nursing population. Increasing the viscosity of liquids, usually with a starch- or xanthan gum-based thickener, serves as a key intervention for patients with dysphagia. We report a newly identified and potentially dangerous interaction between polyethylene glycol 3350 laxative (PEG) and starch-thickened liquids. A patient requiring nectar-thickened liquids became constipated, and medical staff prescribed PEG for constipation. His nurse observed that the thickened apple juice immediately thinned to near-water consistency when PEG was added. She obtained the same results with thickened water and coffee. We quantified this phenomenon by isothermal rotational rheology. Results confirmed a precipitous loss of thickening when PEG was added to starch-based thickeners but not with xanthan gum-based thickeners. Clinicians and front-line staff should be aware of this potentially critical interaction between PEG- and starch-based thickeners. Although confirmatory studies are needed, our preliminary data suggest that PEG may be compatible with xanthan gum-- based thickeners. PMID:27569713

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Surface activity and flocculation behavior of polyethylene glycol-functionalized silica nanoparticles.

    PubMed

    Björkegren, Sanna Maria Sofi; Nordstierna, Lars; Törncrona, Anders; Persson, Michael E; Palmqvist, Anders E C

    2015-08-15

    Colloidal silica nanoparticles have been functionalized with methyl polyethylene glycol silane (mPEG silane) and the PEGylated particles have been characterized with focus on exploring their surface chemical properties. The degree of surface functionalization was quantified using NMR diffusometry, and the measurements showed that the silane binds covalently to the silica surface. Samples with surface coverages ranging from 0.068 to 0.315 μmol silane/m(2) have been analyzed. The functionalized particles proved to be surface active and showed a significant reduction in surface charge and zeta potential with increasing degree of PEG functionalization. All samples showed colloidal stability at neutral pH and above within the range studied. At lower pH, the samples with low surface coverage displayed a reversible flocculation behavior, while samples with a high surface coverage and samples without functionalization remained stable. This suggests that steric stabilization is effective at low pH when the surface coverage is high enough; electrostatic stabilization is effective for samples without functionalization; and that inter-particle PEG-silica interactions cause flocculation of particles with too low degrees of PEG functionalization. PMID:25957235

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

    PubMed

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

    2015-11-01

    Most topical hemostatic agents are based on animal-derived products like collagen and gelatin. They carry the potential risk of pathogen transmission while adjustments in the production process of these materials are limited. A synthetic hemostatic agent based on polyurethane (PU) and polyethylene glycol (PEG) was developed to overcome these disadvantages. The goal of this study was to compare the degradation process of this biomaterial to collagen and gelatin hemostatic agents. Samples of the test materials were implanted subcutaneously in both rats and rabbits. The animals were sacrificed at certain time intervals up to three years and the explanted samples were microscopically assessed. The histological examination showed a comparable pattern of degradation for the different test materials. Remnants of gelatin and collagen were seen up to 26 and 39 weeks, respectively. For PU, it took up to three years before micro-particles of the material were no longer detected. All biomaterials showed a good biocompatibility and no severe foreign body reactions occurred. The good biocompatibility and predictable pattern of resorption indicate that PU can be used as a topical hemostatic agent. However, a degradation time comparable to collagen and gelatin would be favorable. PMID:25904301

  1. Polyethylene Glycol Formulations Show Different Soft Tissue Remodeling and Angiogenesis Features

    PubMed Central

    Oteri, Giacomo; Pizzino, Gabriele; Pisano, Michele; Peditto, Matteo; Squadrito, Francesco

    2015-01-01

    Background: Soft tissue regeneration and remodeling is fundamental in periodontal surgery, thus we investigated the angiogenic response elicited in the subcutaneous tissue of rats by a proprietary, polyethylene glycol hydrogel formulation (PEG) alone or conjugated with specific amelogenins (EMD) or nanobioglass particles (NBG). Methods: Discs with three different formulations (PEG, PEG-EMD, and PEG-NBG) were inserted into four unconnected subcutaneous pouches, produced on the back of Sprague-Dawley rats (n=56, divided into three groups), and used for blood flow evaluation by Laser Doppler analysis at 1, 2, 4, 8, and 16 weeks or for histological and immunohistochemical analysis at 1, 2, 4, 8, and 16 weeks. Results: All formulations showed tissue integration, absence of inflammatory reaction (as revealed by myeloperoxidase staining), and increased vascularization (by counting microvascular density following CD31 staining). Laser Doppler analysis revealed a statistically significant increase in blood flow after 1 week for PEG-EMD and after 2 weeks for PEG-NBG. The angiogenic response was significantly increased at 1, 2, and 8 weeks for PEG-EMD, but only at 4 weeks for PEG-NBG. Conclusions: The studied biomaterials revealed equal biocompatibility and tissue integration properties. PEG-EMD showed the most pronounced and consistent angiogenic response in the early phases of wound healing, while the PEG-NBG formulation provided a slower and delayed, but relevant, response. PMID:25275669

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Chemical dechlorination of hexachlorobenzene with polyethylene glycol and hydroxide: Dominant effect of temperature and ionic potential

    PubMed Central

    Xiao, Ye; Jiang, Jianguo; Huang, Hai

    2014-01-01

    Persistent organic pollutants (POPs) originating from POP waste are playing an increasingly important role in the elevation of regional POP levels. In this study we realized the complete dechlorination of high concentration hexachlorobenzene (HCB) waste in the presence of polyethylene glycol and hydroxide, rather than using conventional high temperature incineration. Here, we demonstrate the dominant effect of temperature and hydroxide on HCB dechlorination in this process. Complete dechlorination of HCB was only observed at temperature about 200°C or above within 4 h reaction, and the apparent activation energy of this process was 43.1 kJ/mol. The alkalinity of hydroxides had notable effects on HCB dechlorination, and there was a considerable linear relationship between the natural logarithm of the HCB dechlorination rate constant and square root of the ionic potential of metal cation (R2 = 0.9997, p = 0.0081, n = 3). This study highlights a promising technology to realize complete dechlorination of POP waste, especially at high concentrations, in the presence of PEG in conjunction with hydroxide. PMID:25200551

  4. Polyethylene glycol-fused allografts produce rapid behavioral recovery after ablation of sciatic nerve segments.

    PubMed

    Riley, D C; Bittner, G D; Mikesh, M; Cardwell, N L; Pollins, A C; Ghergherehchi, C L; Bhupanapadu Sunkesula, S R; Ha, T N; Hall, B T D; Poon, A D; Pyarali, M; Boyer, R B; Mazal, A T; Munoz, N; Trevino, R C; Schallert, T; Thayer, W P

    2015-04-01

    Restoration of neuronal functions by outgrowths regenerating at ∼1 mm/day from the proximal stumps of severed peripheral nerves takes many weeks or months, if it occurs at all, especially after ablation of nerve segments. Distal segments of severed axons typically degenerate in 1-3 days. This study shows that Wallerian degeneration can be prevented or retarded, and lost behavioral function can be restored, following ablation of 0.5-1-cm segments of rat sciatic nerves in host animals. This is achieved by using 0.8-1.1-cm microsutured donor allografts treated with bioengineered solutions varying in ionic and polyethylene glycol (PEG) concentrations (modified PEG-fusion procedure), being careful not to stretch any portion of donor or host sciatic nerves. The data show that PEG fusion permanently restores axonal continuity within minutes, as initially assessed by action potential conduction and intracellular diffusion of dye. Behavioral functions mediated by the sciatic nerve are largely restored within 2-4 weeks, as measured by the sciatic functional index. Increased restoration of sciatic behavioral functions after ablating 0.5-1-cm segments is associated with greater numbers of viable myelinated axons within and distal to PEG-fused allografts. Many such viable myelinated axons are almost certainly spared from Wallerian degeneration by PEG fusion. PEG fusion of donor allografts may produce a paradigm shift in the treatment of peripheral nerve injuries. PMID:25425242

  5. Highly efficient SO₂ absorption and its subsequent utilization by weak base/polyethylene glycol binary system.

    PubMed

    Yang, Zhen-Zhen; He, Liang-Nian; Zhao, Ya-Nan; Yu, Bing

    2013-02-01

    A binary system consisting of polyethylene glycol (PEG, proton donor)/PEG-functionalized base with suitable basicity was developed for efficient gas desulfurization (GDS) and can be regarded as an alternative approach to circumvent the energy penalty problem in the GDS process. High capacity for SO(2) capture up to 4.88 mol of SO(2)/mol of base was achieved even under low partial pressure of SO(2). Furthermore, SO(2) desorption runs smoothly under mild conditions (N(2), 25 °C) and no significant drop in SO(2) absorption was observed after five-successive absorption-desorption cycles. On the other hand, the absorbed SO(2) by PEG(150)MeIm/PEG(150), being considered as the activated form of SO(2), can be directly transformed into value-added chemicals under mild conditions, thus eliminating the energy penalty for SO(2) desorption and simultaneously realizing recycle of the absorbents. Thus, this SO(2) capture and utilization (SCU) process offers an alternative way for GDS and potentially enables the SO(2) conversion from flue gas to useful chemicals as a value-added process. PMID:23323771

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Adsorption efficiency of poly(ethylene glycol)/chitosan/CNT blends for maltene fraction separation.

    PubMed

    Abdeen, Z

    2016-06-01

    Poly(ethylene glycol)/chitosan (PEG/CH) hydrogel and its composite containing carbon nanotubes (PEG/CH/CNTs) were prepared using a simple blending method. The effect of the PEG/CH ratio on the water uptake was studied and optimized. And the prepared hydrogels were characterized by XRD, SEM, and FTIR. Also, the ability of each of the prepared hydrogels to adsorb and separate maltene fractions was compared using saturates, aromatics, resins, and asphaltenes (SARA) method. From the results, it was noticed that the adsorption capacity and separation ability of PEG/CH/CNT are better than that of PEG/CH. But the released amount of alkane fractions using these hydrogels is higher than that in the reference (without using hydrogel). This may be attributed to degradation of maltene residue to alkanes and that degradation is better by using PEG/CH adsorbent than PEG/CH/CNT. Although, from a practical point of view, where PEG/CH/CNT hydrogel may be favorable, it has an acceptable ability to adsorb and separate the maltene fractions. PMID:26922460

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

    PubMed

    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

  9. Subunit stabilization and polyethylene glycolation of cocaine esterase improves in vivo residence time.

    PubMed

    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

    2011-12-01

    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. PMID:21890748

  10. Interaction of hyaluronan binding peptides with glycosaminoglycans in poly(ethylene glycol) hydrogels.

    PubMed

    Roberts, Justine J; Elder, Robert M; Neumann, Alexander J; Jayaraman, Arthi; Bryant, Stephanie J

    2014-04-14

    This study investigates the incorporation of hyaluronan (HA) binding peptides into poly(ethylene glycol) (PEG) hydrogels as a mechanism to bind and retain hyaluronan for applications in tissue engineering. The specificity of the peptide sequence (native RYPISRPRKRC vs non-native RPSRPRIRYKC), the role of basic amino acids, and specificity to hyaluronan over other GAGs in contributing to the peptide-hyaluronan interaction were probed through experiments and simulations. Hydrogels containing the native or non-native peptide retained hyaluronan in a dose-dependent manner. Ionic interactions were the dominating mechanism. In diH2O the peptides interacted strongly with HA and chondroitin sulfate, but in phosphate buffered saline the peptides interacted more strongly with HA. For cartilage tissue engineering, chondrocyte-laden PEG hydrogels containing increasing amounts of HA binding peptide and exogenous HA had increased retention and decreased loss of cell-secreted proteoglycans in and from the hydrogel at 28 days. This new matrix-interactive hydrogel platform holds promise for tissue regeneration. PMID:24597474