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Sample records for homopolymer ethylene glycol

  1. Preparation, loading, and cytotoxicity analysis of polymer nanotubes from an ethylene glycol dimethacrylate homopolymer in comparison to multi‐walled carbon nanotubes

    PubMed Central

    Thomas, Laurent; Zheng, Yu; Steinhart, Martin; Werner, Carsten; Wang, Wenxin

    2016-01-01

    Abstract Despite concerns over toxicity, carbon nanotubes have been extensively investigated for potential applications in nanomedicine because of their small size, unique properties, and ability to carry cargo such as small molecules and nucleic acids. Herein, we show that polymer nanotubes can be synthesized quickly and easily from a homopolymer of ethylene glycol dimethacrylate (EGDMA). The nanotubes formed via photo‐initiated polymerization of the highly functional prepolymer, inside an anodized aluminium oxide template, have a regular structure and large internal pore and can be loaded with a fluorescent dye within minutes representing a simple alternative to multi‐walled carbon nanotubes for biomedical applications. PMID:27512602

  2. Preparation, loading, and cytotoxicity analysis of polymer nanotubes from an ethylene glycol dimethacrylate homopolymer in comparison to multi-walled carbon nanotubes.

    PubMed

    Newland, Ben; Thomas, Laurent; Zheng, Yu; Steinhart, Martin; Werner, Carsten; Wang, Wenxin

    2016-04-01

    Despite concerns over toxicity, carbon nanotubes have been extensively investigated for potential applications in nanomedicine because of their small size, unique properties, and ability to carry cargo such as small molecules and nucleic acids. Herein, we show that polymer nanotubes can be synthesized quickly and easily from a homopolymer of ethylene glycol dimethacrylate (EGDMA). The nanotubes formed via photo-initiated polymerization of the highly functional prepolymer, inside an anodized aluminium oxide template, have a regular structure and large internal pore and can be loaded with a fluorescent dye within minutes representing a simple alternative to multi-walled carbon nanotubes for biomedical applications.

  3. Ethylene glycol

    Integrated Risk Information System (IRIS)

    Ethylene glycol ; CASRN 107 - 21 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  4. Ethylene glycol blood test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003564.htm Ethylene glycol blood test To use the sharing features on ... enable JavaScript. This test measures the level of ethylene glycol in the blood. Ethylene glycol is a type ...

  5. Thin Poly(Di(Ethylene Glycol)Methyl Ether Methacrylate) Homopolymer Brushes Allow Controlled Adsorption and Desorption of PaTu 8988t Cells.

    PubMed

    Voß, Yvonne; Wassel, Ekram; Jiang, Siyu; Song, Qimeng; Druzhinin, Sergey I; Schönherr, Holger

    2016-10-20

    Poly(di(ethylene glycol)methyl ether methacrylate) (PDEGMA) brushes, which are known to suppress protein adsorption and prevent cell attachment, are reported here to possess interesting and tunable thermoresponsive behavior, if the brush thickness is reduced or the grafting density is altered. PDEGMA brushes with a dry ellipsometric thickness of 5 ± 1 nm can be switched from cell adherent behavior at 37 °C to cell nonadherent at 25 °C. This behavior coincides with the temperature-dependent irreversible adsorption of fibronectin from phosphate saline buffer and proteins present in the cell culture medium, as unveiled by surface plasmon resonance measurements. Unlike for tissue culture polystyrene reference surfaces, swelling of the PDEGMA chains below the lower critical solution temperature results in the absence of paxillin and actin containing cellular filaments responsible for cell attachment. These tunable properties of very thin homopolymer PDEGMA brushes render this system interesting as an alternative thermoresponsive layer for continuous cell culture or enzyme-free cell culture systems.

  6. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ethylene oxide homopolymer and/or....3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive is a...

  7. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide homopolymer and/or karaya denture... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification. Ethylene oxide homopolymer and/or...

  8. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide homopolymer and/or....3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive is a...

  9. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ethylene oxide homopolymer and/or....3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive is a...

  10. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ethylene oxide homopolymer and/or....3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive is a...

  11. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ethylene oxide homopolymer and/or karaya denture... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification. Ethylene oxide homopolymer and/or...

  12. 21 CFR 872.3450 - Ethylene oxide homopolymer and/or karaya denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ethylene oxide homopolymer and/or karaya denture... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3450 Ethylene oxide homopolymer and/or karaya denture adhesive. (a) Identification. Ethylene oxide homopolymer and/or...

  13. 21 CFR 872.3410 - Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ethylene oxide homopolymer and/or....3410 Ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive. (a) Identification. An ethylene oxide homopolymer and/or carboxymethylcellulose sodium denture adhesive is a...

  14. Interstellar Antifreeze: Ethylene Glycol

    NASA Astrophysics Data System (ADS)

    Hollis, J. M.; Lovas, F. J.; Jewell, P. R.; Coudert, L. H.

    2002-05-01

    Interstellar ethylene glycol (HOCH2CH2OH) has been detected in emission toward the Galactic center source Sagittarius B2(N-LMH) by means of several millimeter-wave rotational torsional transitions of its lowest energy conformer. The types and kinds of molecules found to date in interstellar clouds suggest a chemistry that favors aldehydes and their corresponding reduced alcohols-e.g., formaldehyde (H2CO)/methanol (CH3OH), acetaldehyde (CH3CHO)/ethanol (CH3CH2OH). Similarly, ethylene glycol is the reduced alcohol of glycolaldehyde (CH2OHCHO), which has also been detected toward Sgr B2(N-LMH). While there is no consensus as to how any such large complex molecules are formed in the interstellar clouds, atomic hydrogen (H) and carbon monoxide (CO) could form formaldehyde on grain surfaces, but such surface chemistry beyond that point is uncertain. However, laboratory experiments have shown that the gas-phase reaction of atomic hydrogen (H) and solid-phase CO at 10-20 K can produce formaldehyde and methanol and that alcohols and other complex molecules can be synthesized from cometary ice analogs when subject to ionizing radiation at 15 K. Thus, the presence of aldehyde/reduced alcohol pairs in interstellar clouds implies that such molecules are a product of a low-temperature chemistry on grain surfaces or in grain ice mantles. This work suggests that aldehydes and their corresponding reduced alcohols provide unique observational constraints on the formation of complex interstellar molecules.

  15. Interstellar Antifreeze: Ethylene Glycol

    NASA Technical Reports Server (NTRS)

    Hollis, J. M.; Lovas, F. J.; Jewell, P. R.; Coudert, L. H.

    2002-01-01

    Interstellar ethylene glycol (HOCH2CH2,OH) has been detected in emission toward the Galactic center source Sagittarius B2(N-LMH) by means of several millimeter-wave rotational torsional transitions of its lowest energy conformer. The types and kinds of molecules found to date in interstellar clouds suggest a chemistry that favors aldehydes and their corresponding reduced alcohols-e.g., formaldehyde (H2CO)/methanol (CH3OH), acetaldehyde (CH3CHO)/ethanol (CH3CH2OH). Similarly, ethylene glycol is the reduced alcohol of glycolaldehyde (CH2OHCHO), which has also been detected toward Sgr B2(N-LMH). While there is no consensus as to how any such large complex molecules are formed in the interstellar clouds, atomic hydrogen (H) and carbon monoxide (CO) could form formaldehyde on grain surfaces, but such surface chemistry beyond that point is uncertain. However, laboratory experiments have shown that the gas-phase reaction of atomic hydrogen (H) and solid-phase CO at 10-20 K can produce formaldehyde and methanol and that alcohols and other complex molecules can be synthesized from cometary ice analogs when subject to ionizing radiation at 15 K. Thus, the presence of aldehyde/ reduced alcohol pairs in interstellar clouds implies that such molecules are a product of a low-temperature chemistry on grain surfaces or in grain ice mantles. This work suggests that aldehydes and their corresponding reduced alcohols provide unique observational constraints on the formation of complex interstellar molecules.

  16. Interstellar Antifreeze: Ethylene Glycol

    NASA Technical Reports Server (NTRS)

    Hollis, J. M.; Lovas, F. J.; Jewell, P. R.; Coudert, L. H.

    2002-01-01

    Interstellar ethylene glycol (HOCH2CH2,OH) has been detected in emission toward the Galactic center source Sagittarius B2(N-LMH) by means of several millimeter-wave rotational torsional transitions of its lowest energy conformer. The types and kinds of molecules found to date in interstellar clouds suggest a chemistry that favors aldehydes and their corresponding reduced alcohols-e.g., formaldehyde (H2CO)/methanol (CH3OH), acetaldehyde (CH3CHO)/ethanol (CH3CH2OH). Similarly, ethylene glycol is the reduced alcohol of glycolaldehyde (CH2OHCHO), which has also been detected toward Sgr B2(N-LMH). While there is no consensus as to how any such large complex molecules are formed in the interstellar clouds, atomic hydrogen (H) and carbon monoxide (CO) could form formaldehyde on grain surfaces, but such surface chemistry beyond that point is uncertain. However, laboratory experiments have shown that the gas-phase reaction of atomic hydrogen (H) and solid-phase CO at 10-20 K can produce formaldehyde and methanol and that alcohols and other complex molecules can be synthesized from cometary ice analogs when subject to ionizing radiation at 15 K. Thus, the presence of aldehyde/ reduced alcohol pairs in interstellar clouds implies that such molecules are a product of a low-temperature chemistry on grain surfaces or in grain ice mantles. This work suggests that aldehydes and their corresponding reduced alcohols provide unique observational constraints on the formation of complex interstellar molecules.

  17. Crystal structures of ethylene glycol and ethylene glycol monohydrate.

    PubMed

    Fortes, A Dominic; Suard, Emmanuelle

    2011-12-21

    We have carried out a neutron powder diffraction study of deuterated ethylene glycol (1,2-ethanediol), and deuterated ethylene glycol monohydrate with the D2B high-resolution diffractometer at the Institut Laue-Langevin. Using these data, we have refined the complete structure, including all hydrogen atoms, of the anhydrous phase at 220 K. In addition, we have determined the structure of ethylene glycol monohydrate at 210 K using direct space methods. Anhydrous ethylene glycol crystallizes in space-group P2(1)2(1)2(1) with four formula units in a unit-cell of dimensions a = 5.0553(1) Å, b = 6.9627(1) Å, c = 9.2709(2) Å, and V = 326.319(8) Å(3) [ρ(calc)(deuterated) = 1386.26(3) kg m(-3)] at 220 K. Ethylene glycol monohydrate crystallizes in space-group P2(1)/c with four formula units in a unit-cell of dimensions a = 7.6858(3) Å, b = 7.2201(3) Å, c = 7.7356(4) Å, β = 92.868(3)°, and V = 428.73(2) Å(3) [ρ(calc)(deuterated) = 1365.40(7) kg m(-3)] at 210 K. Both the structures are characterized by the gauche conformation of the ethylene glycol molecule; however, the anhydrous phase contains the tGg' rotamer (or its mirror, g'Gt), whereas the monohydrate contains the gGg' rotamer. In the monohydrate, each water molecule is tetrahedrally coordinated, donating two hydrogen bonds to, and accepting two hydrogen bonds from the hydroxyl groups of neighboring ethylene glycol molecules. There are substantial differences in the degree of weak C-D···O hydrogen bonding between the two crystals, which calls into question the role of these interactions in determining the conformation of the ethylene glycol molecule.

  18. Colorometric detection of ethylene glycol vapor

    NASA Technical Reports Server (NTRS)

    Helm, C.; Mosier, B.; Verostko, C. E.

    1970-01-01

    Very low concentrations of ethylene glycol in air or other gases are detected by passing a sample through a glass tube with three partitioned compartments containing reagents which successively convert the ethylene glycol vapor into a colored compound.

  19. Serum Calcium Concentration in Ethylene Glycol Poisoning.

    PubMed

    Hodgman, Michael; Marraffa, Jeanna M; Wojcik, Susan; Grant, William

    2017-06-01

    The diagnosis of ethylene glycol intoxication can be challenging. Definitive testing for ethylene glycol is not readily available and clinical decisions are often based on clinical suspicion and the results of more readily available tests. One of these findings is hypocalcemia, presumable through complexation with the ethylene glycol metabolite oxalate. We performed a retrospective review of all patients admitted to a tertiary care hospital between 2005 and 2013 with laboratory confirmed ethylene glycol intoxication. Serum calcium on presentation was compared to blood gas pH on presentation as well as presentation serum bicarbonate. We did not find any relationship between calcium and serum pH either by linear regression or when dichotomized by pH ≥ or <7.3. We did observe an inverse relationship between serum calcium and bicarbonate. Hypocalcemia is not commonly observed following ethylene glycol poisoning, even in acidotic patients.

  20. Ethylene Glycol and Metabolite Concentrations in Fatal Ethylene Glycol Poisonings.

    PubMed

    Viinamäki, Jenni; Sajantila, Antti; Ojanperä, Ilkka

    2015-01-01

    Ethylene glycol (EG) is used in antifreeze and other industrial products. It metabolizes to glycolic acid (GA) and oxalic acid (OX) that cause metabolic acidosis and are mainly responsible for the toxicity of EG. During 2010-2014, EG or GA was found in 25 postmortem cases in Finland. Of these cases, 21 were classified as fatal EG poisonings and 3 were classified as methanol (MeOH) poisonings. In this study, we report the concentrations of EG and GA in postmortem blood and urine samples of fatal EG or mixed MeOH/EG poisonings. In the fatal EG poisonings, the median EG and GA concentrations were 0.87 and 1.6 g/L in blood and 4.3 and 5.3 g/L in urine. The median urine-blood ratios were 3.8 and 3.1 for EG and GA. These results warrant the use of urine as a primary matrix for screening. In EG positive cases, the quantification of both EG and GA in blood is crucial as GA concentration appears to best indicate a fatal poisoning with an approximate threshold of 1.5 g/L. The measurement of urinary OX does not offer much additional value to toxic alcohol screening as it may originate from varying dietary conditions. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Glycolic acid production using ethylene glycol-oxidizing microorganisms.

    PubMed

    Kataoka, M; Sasaki, M; Hidalgo, A R; Nakano, M; Shimizu, S

    2001-10-01

    Screening for microorganisms oxidizing ethylene glycol to glycolic acid was carried out. Among stock cultures, several yeasts and acetic acid bacteria showed high glycolic acid producing activity. Pichia naganishii AKU 4267 formed the highest concentration of glycolic acid, 35.3 g/l, from 10% (v/v) ethylene glycol (molar conversion yield, 26.0%). Among soil isolates, Rhodotorula sp. 3Pr-126, isolated using propylene glycol as a sole carbon source, formed the highest concentration of glycolic acid, 25.1 g/l, from 10% (v/v) ethylene glycol (molar conversion yield, 18.5%). Rhodotorula sp. 3Pr-126 showed higher activity toward 20% (v/v) ethylene glycol than P. naganishii AKU 4267. Optimization of the conditions for glycolic acid production was investigated using P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126. Under the optimized conditions, P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126 formed 105 and 110 g/l of glycolic acid (corrected molar conversion yields, 88.0 and 92.2%) during 120 h of reaction, respectively.

  2. Ethylene Glycol Metabolism by Pseudomonas putida

    PubMed Central

    Mückschel, Björn; Simon, Oliver; Klebensberger, Janosch; Graf, Nadja; Rosche, Bettina; Altenbuchner, Josef; Pfannstiel, Jens; Huber, Armin

    2012-01-01

    In this study, we investigated the metabolism of ethylene glycol in the Pseudomonas putida strains KT2440 and JM37 by employing growth and bioconversion experiments, directed mutagenesis, and proteome analysis. We found that strain JM37 grew rapidly with ethylene glycol as a sole source of carbon and energy, while strain KT2440 did not grow within 2 days of incubation under the same conditions. However, bioconversion experiments revealed metabolism of ethylene glycol by both strains, with the temporal accumulation of glycolic acid and glyoxylic acid for strain KT2440. This accumulation was further increased by targeted mutagenesis. The key enzymes and specific differences between the two strains were identified by comparative proteomics. In P. putida JM37, tartronate semialdehyde synthase (Gcl), malate synthase (GlcB), and isocitrate lyase (AceA) were found to be induced in the presence of ethylene glycol or glyoxylic acid. Under the same conditions, strain KT2440 showed induction of AceA only. Despite this difference, the two strains were found to use similar periplasmic dehydrogenases for the initial oxidation step of ethylene glycol, namely, the two redundant pyrroloquinoline quinone (PQQ)-dependent enzymes PedE and PedH. From these results we constructed a new pathway for the metabolism of ethylene glycol in P. putida. Furthermore, we conclude that Pseudomonas putida might serve as a useful platform from which to establish a whole-cell biocatalyst for the production of glyoxylic acid from ethylene glycol. PMID:23023748

  3. Ethylene glycol metabolism by Pseudomonas putida.

    PubMed

    Mückschel, Björn; Simon, Oliver; Klebensberger, Janosch; Graf, Nadja; Rosche, Bettina; Altenbuchner, Josef; Pfannstiel, Jens; Huber, Armin; Hauer, Bernhard

    2012-12-01

    In this study, we investigated the metabolism of ethylene glycol in the Pseudomonas putida strains KT2440 and JM37 by employing growth and bioconversion experiments, directed mutagenesis, and proteome analysis. We found that strain JM37 grew rapidly with ethylene glycol as a sole source of carbon and energy, while strain KT2440 did not grow within 2 days of incubation under the same conditions. However, bioconversion experiments revealed metabolism of ethylene glycol by both strains, with the temporal accumulation of glycolic acid and glyoxylic acid for strain KT2440. This accumulation was further increased by targeted mutagenesis. The key enzymes and specific differences between the two strains were identified by comparative proteomics. In P. putida JM37, tartronate semialdehyde synthase (Gcl), malate synthase (GlcB), and isocitrate lyase (AceA) were found to be induced in the presence of ethylene glycol or glyoxylic acid. Under the same conditions, strain KT2440 showed induction of AceA only. Despite this difference, the two strains were found to use similar periplasmic dehydrogenases for the initial oxidation step of ethylene glycol, namely, the two redundant pyrroloquinoline quinone (PQQ)-dependent enzymes PedE and PedH. From these results we constructed a new pathway for the metabolism of ethylene glycol in P. putida. Furthermore, we conclude that Pseudomonas putida might serve as a useful platform from which to establish a whole-cell biocatalyst for the production of glyoxylic acid from ethylene glycol.

  4. Toxicity of ethylene glycol, diethylene glycol, and propylene glycol to human cells in culture

    SciTech Connect

    Mochida, K.; Gomyoda, M.

    1987-01-01

    Tissue culture toxicity of various alcohols has been reported by Dillingham who used mouse L cells and Koerker who used mouse neuroblastoma cells. The toxicity of various polyhydric alcohols (ethylene glycol, diethylene glycol and propylene glycol) has apparently not been determined, under conditions of culture. The authors report the toxicity of ethylene glycol, diethylene glycol and propylene glycol and KB cells and the results are compared with previous data obtained using their cell culture system.

  5. 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.

  6. Inert Reassessment Document for Ethylene Glycol

    EPA Pesticide Factsheets

    Ethylene Glycol has many uses and are also used as antifreeze and deicers, as solvents, humectants, as chemical intermediates in the synthesis of other chemicals, and as components of many products such as brake fluids, lubricants, inks,and lacquers.

  7. Taste responses of dogs to ethylene glycol, propylene glycol, and ethylene glycol-based antifreeze.

    PubMed

    Marshall, D A; Doty, R L

    1990-12-15

    Although it is widely believed that ethylene glycol-based antifreeze (AF) is an attractive tastant to dogs and other animals, empirical data on this point are not available. In experiment 1, we examined the propensity of 178 adult mixed-breed dogs to approach, sniff, and lick a concentration of AF commonly used in automotive cooling systems (50%). Despite the fact that most of the dogs approached and sniffed the AF in these 5-minute tests, only 9% initiated lick responses and most of these were brief and not followed by additional licking. In experiment 2, the lick responses of five gastric-cannulated dogs to aqueous solutions of 20% sucrose, 50% ethylene glycol, 50% propylene glycol, water, and 50% AF were examined in 14-minute tests before and after periods of food and water deprivation. Under the latter conditions, 2 of the 5 dogs drank amounts of ethylene glycol that would have been lethal to uncannulated dogs. None of the five dogs drank potentially lethal amounts of AF. The preference order for these tastants was sucrose greater than water greater than ethylene glycol greater than AF = propylene glycol. Although these findings question the general belief that AF is highly palatable to most dogs, they do imply that large individual differences in responsiveness exist and that AF ingestion is likely influenced by motivational state. Furthermore, they suggest the possibility that unpleasant-tasting additives could be successfully developed to eliminate the ingestion of AF, because the initial attractiveness of AF is relatively low. Such additives would have to be stable in vehicular cooling systems and not adversely affect the functional aspects of AF performance.

  8. Ethylene glycol and glycolate kinetics in rats and dogs.

    PubMed

    Hewlett, T P; Jacobsen, D; Collins, T D; McMartin, K E

    1989-04-01

    Ethylene glycol (EG) toxicity results from its metabolism to glycolic acid and other toxic metabolites. The accumulation of glycolate and the elimination kinetics of EG and its metabolites are not well understood, so studies with male Sprague-Dawley rats and mixed breed dogs have been carried out. EG was administered by gavage to rats and dogs, which were placed in metabolic cages for urine and blood sample collection at timed intervals. The peak plasma level of EG occurred at 2 hr after dosing and that of glycolate between 4-6 hr. The rate of EG elimination was somewhat faster in rats with a half-life of 1.7 hr compared to 3.4 hr in dogs. The maximum plasma level of glycolate was greater in rats, although the pattern of accumulation was similar to that in dogs. Glycolate disappeared from the plasma at the same time as EG, suggesting a slower rate of elimination of the metabolite than that of EG. Renal excretion of EG was an important route for its elimination, accounting for 20-30% of the dose. Renal excretion of glycolate represented about 5% of the dose. EG induced an immediate, but short-lived diuresis compared to that in control rats. Minimal clinical effects (mild acidosis with no sedation) were noted at these doses of EG (1-2 g/kg) in both rats and dogs. The results indicate that the toxicokinetics of EG and glycolate were similar in both species.

  9. Ethylene glycol monobutyl ether (EGBE) (2-Butoxyethanol)

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 08 / 006F www.epa.gov / iris TOXICOLOGICAL REVIEW OF ETHYLENE GLYCOL MONOBUTYL ETHER ( EGBE ) ( CAS No . 111 - 76 - 2 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) March 2010 U.S . Environmental Protection Agency Washington , DC DISCLAIMER Thi

  10. Multidimensional chromatographic techniques for hydrophilic copolymers II. Analysis of poly(ethylene glycol)-poly(vinyl acetate) graft copolymers.

    PubMed

    Knecht, Daniela; Rittig, Frank; Lange, Ronald F M; Pasch, Harald

    2006-10-13

    A large variety of hydrophilic copolymers is applied in different fields of chemical industry including bio, pharma and pharmaceutical applications. For example, poly(ethylene glycol)-poly(vinyl alcohol) graft copolymers that are used as tablet coatings are responsible for the controlled release of the active compounds. These copolymers are produced by grafting of vinyl acetate onto polyethylene glycol (PEG) and subsequent hydrolysis of the poly(ethylene glycol)-poly(vinyl acetate) graft copolymers. The poly(ethylene glycol)-poly(vinyl acetate) copolymers are distributed with regard to molar mass and chemical composition. In addition, they frequently contain the homopolymers polyethylene glycol and polyvinyl acetate. The comprehensive analysis of such complex systems requires hyphenated analytical techniques, including two-dimensional liquid chromatography and combined LC and nuclear magnetic resonance spectroscopy. The development and application of these techniques are discussed in the present paper.

  11. The synthesis of ethylene glycol from formaldehyde

    NASA Astrophysics Data System (ADS)

    Korneeva, G. A.; Loktev, S. M.

    1989-01-01

    The literature and patent data on the hydroformylation of formaldehyde to glycolaldehyde — an intermediate in the synthesis of ethylene glycol — are surveyed. The principal types of catalytic systems based on rhodium and cobalt carbonyl complexes and the characteristic features of the reaction are examined and compared with the hydroformylation of olefins. The reaction mechanism is discussed in the light of the reactions of the formaldehyde complexes of transition metals. The bibliography includes 116 references.

  12. [Interference of ethylene glycol on lactate assays].

    PubMed

    Graïne, H; Toumi, K; Roullier, V; Capeau, J; Lefèvre, G

    2007-01-01

    Ethylene glycol is broken down to three main organic acids: glycolic acid, glyoxylic acid and oxalic acid which cause severe metabolic acidosis. Effect of these three acids on lactate assays was evaluated in five blood gas analysers and two clinical chemistry analysers. For all systems, no influence of oxalic acid on lactate results could be demonstrated. No interference of glycolic acid could be observed on lactate assay performed with Rapid Lab 1265 (R: 104,9 +/- 12,1%), Vitros 950 (R: 105,7 +/- 5,3 %) and Architect ci8200 (R: 104,9 +/- 4,7%), but on the contrary, CCX 4, OMNI S, ABL 725 and 825 demonstrated a concentration-dependent interference. No interference of glyoxylic acid could be observed with Vitros 950, but a positive interference could be observed with ABL 725 and 825, OMNI S, CCX4 and Architect ci8200 A linear relationship between apparent lactate concentration found with ABL 725 and 825, OMNI S, CCX 4, and glyoxylic acid could be observed (0,94 < r < 0,99), a weaker interference being observed with Rapid Lab 1265 and Architect ci 8200. Our results demonstrated that in case of ethylene glycol poisoning, cautious interpretation of lactate assay should be done, since wrong results of lactacidemia could lead to misdiagnostic and delay patient treatment.

  13. [Severe ethylene glycol poisoning treated wtih fomepizole (4-methylpyrazole)].

    PubMed

    Aakervik, Odd; Svendsen, Jan; Jacobsen, Dag

    2002-10-20

    Poisoning with ethylene glycol causes severe metabolic acidosis and renal failure, and is potentially lethal if not treated rapidly. Until recently the standard therapy for this poisoning has been bicarbonate to counteract the metabolic acidosis, inhibition of alcohol dehydrogenase (ADH) with ethanol to prevent the production of toxic metabolites and haemodialysis to remove ethylene glycol and its toxic metabolites. The new potent inhibitor of ADH, 4-methylpyrazole (fomepizole), has recently been approved for the treatment of methanol and ethylene glycol poisonings. Three patients severely poisoned by ethylene glycol and treated with fomepizole are presented. Of our three patients treated with fomepizole two were managed without haemodialysis. One patient had an exceptionally high serum ethylene glycol concentration (90 mmol/l; 585 mg/dl) and was successfully treated with fomepizole without the need for haemodialysis despite pronounced metabolic acidosis. Ethylene glycol poisonings may be treated effectively with fomepizole without haemodialysis.

  14. Extraction of ethylene glycol from aqueous salt solutions

    NASA Astrophysics Data System (ADS)

    Butyrskaya, E. V.; Belyakova, N. V.; Rozhkova, M. V.; Nechaeva, L. S.

    2012-11-01

    A method is proposed for extracting ethylene glycol from aqueous salt solutions by dialysis through ion-exchange membranes, based on the Donnan exclusion of the electrolyte. Dialysis is performed in the continuous and batch modes. It is found that the batch mode of dialysis is more effective for extracting ethylene glycol from its aqueous salt solutions. The effect of the ionic form of the membrane on ethylene glycol fluxes is explained through computer simulation.

  15. Sorption interactions between ethylene glycol and carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Butyrskaya, E. V.; Belyakova, N. V.; Nechaeva, L. S.; Shaposhnik, V. A.; Selemenev, V. F.

    2017-03-01

    The adsorption of ethylene glycol by carbon nanoparticles is studied. Carbon nanoparticles with the highest affinity to ethylene glycol are identified, and an adsorption isotherm is constructed. Based on quantum chemical calculations of the energies of interaction between the sorbate and nanotubes with (4,4) and (6,6) chirality, a change in mechanism is revealed upon the monomolecular adsorption of ethylene glycol on carbon nanotubes, and the adsorption isotherm is thus interpreted.

  16. Simulation of Doxorubicin Delivery via Glucosamine(ethylene glycol) Carrier

    PubMed Central

    Pirawattana, Thongjun; Srinophakun, Thongchai

    2008-01-01

    This article focuses on the molecular modeling of the release of doxorubicin from capsules composed of glucosamine(ethylene glycol) oligomers. Doxorubicin forms micelle structures with glucosamine(ethylene glycol), and the drug release mechanism can be studied through the modeling of oligomeric bond breaking under acidic, neutral, or basic conditions. Under these conditions, the activation energies were calculated to be 145.51, 135.78, and 287.60 kcal/mol, respectively, at the B3LYP/6-31G//PM3 level. Based on these values, doxorubicin can be released into acidic and neutral solutions but not into basic solution. Ethylene glycol chain length in glucosamine(ethylene glycol) also effects drug release. As the length of ethylene glycol increases, the amount of drug released increases under acidic conditions, but decreases under neutral and basic conditions. When the drug is released from glucosamine(ethylene glycol) oligomers, the drug molecule and glucosamine(ethylene glycol) molecules form a micelle structure. Studies found that, as the length of the ethylene glycol chains increases, the micelle structure is more easily formed. The ethylene glycol group can deliver doxorubicin to cancer cells in micelle form. PMID:19330076

  17. Synthesis and characterization of injectable, water-soluble copolymers of tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates.

    PubMed

    Anderson, Brian C; Mallapragada, Surya K

    2002-11-01

    Several homopolymers and copolymers of 2-(diethylamino)ethyl methacrylate (DEAEM) and poly(ethylene glycol) methyl ether methacrylate (PEGMEM) were synthesized using anionic polymerization initiated by potassium t-butoxide. The polymers were characterized by average molecular weight, polydispersity and monomeric unit composition. A very narrow molecular weight distribution was achieved with a well-controlled composition. The glass transition temperatures and compositions of the copolymers followed a Gordon-Taylor relationship. The water solubility and biocompatibility of the copolymers was compared to their parent homopolymers to determine if the addition of a poly(ethylene glycol) group was sufficient to solubilize the polymers in aqueous buffer solutions and to increase the biocompatibility of the polymers. These water-soluble, injectable cationic copolymers have potential applications in gene delivery as well as other biomaterial applications.

  18. Biosynthesis of ethylene glycol in Escherichia coli.

    PubMed

    Liu, Huaiwei; Ramos, Kristine Rose M; Valdehuesa, Kris Niño G; Nisola, Grace M; Lee, Won-Keun; Chung, Wook-Jin

    2013-04-01

    Ethylene glycol (EG) is an important platform chemical with steadily expanding global demand. Its commercial production is currently limited to fossil resources; no biosynthesis route has been delineated. Herein, a biosynthesis route for EG production from D-xylose is reported. This route consists of four steps: D-xylose → D-xylonate → 2-dehydro-3-deoxy-D-pentonate → glycoaldehyde → EG. Respective enzymes, D-xylose dehydrogenase, D-xylonate dehydratase, 2-dehydro-3-deoxy-D-pentonate aldolase, and glycoaldehyde reductase, were assembled. The route was implemented in a metabolically engineered Escherichia coli, in which the D-xylose → D-xylulose reaction was prevented by disrupting the D-xylose isomerase gene. The most efficient construct produced 11.7 g L(-1) of EG from 40.0 g L(-1) of D-xylose. Glycolate is a carbon-competing by-product during EG production in E. coli; blockage of glycoaldehyde → glycolate reaction was also performed by disrupting the gene encoding aldehyde dehydrogenase, but from this approach, EG productivity was not improved but rather led to D-xylonate accumulation. To channel more carbon flux towards EG than the glycolate pathway, further systematic metabolic engineering and fermentation optimization studies are still required to improve EG productivity.

  19. Crystallization of toxic glycol solvates of rifampin from glycerin and propylene glycol contaminated with ethylene glycol or diethylene glycol.

    PubMed

    de Villiers, Melgardt M; Caira, Mino R; Li, Jinjing; Strydom, Schalk J; Bourne, Susan A; Liebenberg, Wilna

    2011-06-06

    This study was initiated when it was suspected that syringe blockage experienced upon administration of a compounded rifampin suspension was caused by the recrystallization of toxic glycol solvates of the drug. Single crystal X-ray structure analysis, powder X-ray diffraction, thermal analysis and gas chromatography were used to identify the ethylene glycol in the solvate crystals recovered from the suspension. Controlled crystallization and solubility studies were used to determine the ease with which toxic glycol solvates crystallized from glycerin and propylene glycol contaminated with either ethylene or diethylene glycol. The single crystal structures of two distinct ethylene glycol solvates of rifampin were solved while thermal analysis, GC analysis and solubility studies confirmed that diethylene glycol solvates of the drug also crystallized. Controlled crystallization studies showed that crystallization of the rifampin solvates from glycerin and propylene glycol depended on the level of contamination and changes in the solubility of the drug in the contaminated solvents. Although the exact source of the ethylene glycol found in the compounded rifampin suspension is not known, the results of this study show how important it is to ensure that the drug and excipients comply with pharmacopeial or FDA standards.

  20. Comparison of biodegradation of poly(ethylene glycol)s and poly(propylene glycol)s.

    PubMed

    Zgoła-Grześkowiak, Agnieszka; Grześkowiak, Tomasz; Zembrzuska, Joanna; Łukaszewski, Zenon

    2006-07-01

    The biodegradation of poly(ethylene glycol)s (PEGs) and poly(propylene glycol)s (PPGs), both being major by-products of non-ionic surfactants biodegradation, was studied under the conditions of the River Water Die-Away Test. PEGs were isolated from a water matrix using solid-phase extraction with graphitized carbon black sorbent, then derivatized with phenyl isocyanate and determined by HPLC with UV detection. PPGs were isolated from a water matrix by liquid-liquid extraction with chloroform, then derivatized with naphthyl isocyanate and determined by HPLC with fluorescence detection. The primary biodegradation of both PEGs and PPGs reached approximately 99% during the test. The tests show different biodegradation pathways of PEG and PPG. During PEG biodegradation, their chains are shortened leading to the formation of ethylene glycol and diethylene glycol. During PPG biodegradation, no short-chained biodegradation products were found.

  1. [Ethylene glycol and propylene glycol ethers - Reproductive and developmental toxicity].

    PubMed

    Starek-Świechowicz, Beata; Starek, Andrzej

    2015-01-01

    Both ethylene and propylene glycol alkyl ethers (EGAEs and PGAEs, respectively) are widely used, mainly as solvents, in industrial and household products. Some EGAEs demonstrate gonadotoxic, embriotoxic, fetotoxic and teratogenic effects in both humans and experimental animals. Due to the noxious impact of these ethers on reproduction and development of organisms EGAEs are replaced for considerably less toxic PGAEs. The data on the mechanisms of testicular, embriotoxic, fetotoxic and teratogenic effects of EGAEs are presented in this paper. Our particular attention was focused on the metabolism of some EGAEs and their organ-specific toxicities, apoptosis of spermatocytes associated with changes in the expression of various genes that code for oxidative stress factors, protein kinases and nuclear hormone receptors. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  2. False hyperlactatemia in life-threatening ethylene glycol poisoning.

    PubMed

    Riquier, T; Geri, G; Mongardon, N; Bourgogne, E; Pène, F

    2014-04-01

    Ethylene glycol poisoning is rare, but prompt diagnosis is crucial, in order to initiate specific treatments. Herein, we report the case of a patient who was admitted to ICU for coma and extreme metabolic acidosis with unexpected hyperlactatemia on initial ICU blood gas analyzer. Ethylene glycol poisoning was diagnosed, and hyperlactatemia was ruled out on a blood sample sent to the biochemistry department. Interference of blood gas analyzers lactate electrodes with metabolites of ethylene glycol were the source of this apparent hyperlactatemia. Symptoms gradually improved and false hyperlactatemia resolved after renal replacement therapy and fomepizole administration. Time course of ethylene glycol concentration showed similar evolution. After initial confirmation of ethylene glycol presence, this biological interference could thus be used as a surrogate of costly and highly specialised dosages. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  3. Self-diffusion coefficients of hexamethylphosphoric triamide and ethylene glycol molecules in ethylene glycol solutions

    NASA Astrophysics Data System (ADS)

    Idiyatullin, Z. Sh.; Solonina, I. A.; Rodnikova, M. N.; Sirotkin, D. A.

    2017-08-01

    The self-diffusion coefficients of the molecules of hexamethylphosphoric triamide (HMPT) and ethylene glycol (EG) in ethylene glycol solutions in the concentration range 0-16 mol % HMPT and molecules of pure HMPT in the temperature range 30-60°C are measured by the spin-echo method on protons. Activation energies for the corresponding processes of self-diffusion were calculated. The obtained data are discussed in terms of solvophobic effects in the EG-HMPT system. The self-diffusion coefficient of pure HMPT was 0.344 × 10-5 cm2/s at 33.2°C, and the self-diffusion activation energy was 3.86 kcal/mol.

  4. Degradation of ethylene glycol using Fenton's reagent and UV.

    PubMed

    McGinnis, B D; Adams, V D; Middlebrooks, E J

    2001-10-01

    Oxidation of ethylene glycol in aqueous solutions was found to occur with the addition of Fenton's reagent with further conversion observed upon UV irradiation. The pH range studied was 2.5-9.0 with initial H2O2 concentrations ranging from 100 to 1000 mg/l. Application of this method to airport storm-water could potentially result in reduction of chemical oxygen demand by conversion of ethylene glycol to oxalic and formic acids. Although the amount of H2O2 added follows the amount of ethylene glycol degraded, smaller H2O2 doses were associated with increases in the ratio of ethylene glycol removed per unit H2O2 added indicating the potential of pulsed doses or constant H2O2 feed systems. Ethylene glycol removal was enhanced by exposure to UV light after treatment with Fenton's reagent, with rates dependent on initial H2O2 concentration. In addition to ethylene glycol, the principle products of this reaction, oxalic and formic acids, have been shown to be mineralized in other HO generating systems presenting the potential for ethylene glycol mineralization in this system with increased HO* production.

  5. Role of fomepizole in the management of ethylene glycol toxicity.

    PubMed

    Druteika, Deon P; Zed, Peter J; Ensom, Mary H H

    2002-03-01

    To systematically review English-language articles on fomepizole administration in patients with ethylene glycol poisoning. MEDLINE, EMBASE, Current Contents, and PubMed. Search terms were fomepizole, 4-methylpyrazole, and ethylene glycol. The search was supplemented with a bibliographic review of all relevant articles. All published reports of fomepizole administration in patients with ethylene glycol poisoning were reviewed, irrespective of study design. We identified one clinical trial and subsequent pharmacokinetic study, one case series, and 13 case reports. Fomepizole has been investigated in 70 patients in open, unblinded studies. Most patients received an intravenous loading dose, with subsequent variable maintenance doses every 12 hours until plasma ethylene glycol levels became undetectable. Additional hemodialysis treatment generally was administered when patients had renal insufficiency or ethylene glycol levels above 50 mg/dl. Many patients had detectable ethanol levels either because of coadministration or as a result of adjunctive treatment at a referring center. Poorer patient outcomes, such as death and renal insufficiency, were associated with later clinical presentation time after ingestion. At therapeutic fomepizole levels (> 8.6 mg/ml), the half-life of ethylene glycol was prolonged to over 19 hours. Fomepizole appeared to be well tolerated by most patients. Fomepizole is an effective alcohol dehydrogenase inhibitor that decreases production of ethylene glycol metabolites. Reduced mortality and morbidity are undetermined because of the small number of patients evaluated to date. Data on comparative efficacy of fomepizole versus ethanol and data on administration of fomepizole in children are limited.

  6. 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.

  7. Enhanced bioconversion of ethylene glycol to glycolic acid by a newly isolated Burkholderia sp. EG13.

    PubMed

    Gao, Xiaoxin; Ma, Zhengfei; Yang, Limin; Ma, Jiangquan

    2014-10-01

    Burkholderia sp. EG13 with high ethylene glycol-oxidizing activity was isolated from soil, which could be used for the synthesis of glycolic acid from the oxidation of ethylene glycol. Using the resting cells of Burkholderia sp. EG13 as biocatalysts, the optimum reaction temperature and pH were 30 °C and 6.0, respectively. After 24 h of biotransformation, the yield of glycolic acid from 200 mM ethylene glycol was 98.8 %. Furthermore, an integrated bioprocess for the production of glycolic acid which involved in situ product removal (ISPR) was investigated. Using fed-batch method with ISPR, a total of 793 mM glycolic acid has been accumulated in the reaction mixture after the 4th feed.

  8. Analysis of automobile radiator performance with ethylene glycol/water and propylene glycol/water coolants

    SciTech Connect

    Gollin, M.; Bjork, D.

    1996-12-31

    The heat transfer and hydraulic performance of the following coolants was examined in five automobile radiators in a wind tunnel: 100% water; 100% propylene glycol; 70/30 propylene glycol/water (volume); 50/50 propylene glycol/water (volume); 70/30 ethylene glycol/water (volume); 50/50 ethylene glycol water (volume). The results of these studies are presented to demonstrate the relative performance of these coolant mixtures in terms of heat transfer, coolant pressure drop and radiator effectiveness for a range of coolant and air flowrates. It is concluded that the most effective of the coolants in transferring heat in the test radiators was water, followed by 50/50 ethylene glycol/water, 50/50 propylene glycol/water, 70/30 ethylene glycol/water, 70/30 propylene glycol and, finally, 100% propylene glycol. There will be a negligible differences between the performance of a radiator using a 50/50 propylene glycol/water coolant and a 50/50 ethylene glycol/water coolant. It is estimated that, with 50/50 propylene glycol coolant replacing 50/50 ethylene glycol/water, the temperature of the coolant throughout the cooling loop will increase by approximately 5%. The effect that the flow regime (fully turbulent/transition/laminar) has upon the performance of a given radiator/coolant combination was found to be significant. The design of the coolant passages in radiators can affect the onset of fully turbulent flow in the coolant passages in a radiator.

  9. Evaluation of workers exposed to ethylene glycol monomethyl ether and ethylene glycol monomethyl ether acetate.

    PubMed

    Park, Jiyoung; Yoon, Chungsik; Byun, Hyaejeong; Kim, Yangho; Park, Donguk; Ha, Kwonchul; Lee, Sang man; Park, Sungki; Chung, Eunkyo

    2012-01-01

    Ethylene glycol monomethyl ether (EGME) and ethylene glycol monomethyl ether acetate (EGMEA) are widely used in industries as solvents for coatings, paint and ink, but exposure data are limited because they are minor components out of mixed solvents, as well as because of inconsistency in desorption solvent use. The objective of this study was to investigate the worker exposure profile of EGME and EGMEA. Our study investigated 27 workplaces from June to September 2008 and detected EGME and EGMEA in 20 and 13, respectively. Both personal and area sampling were conducted using a charcoal tube to collect EGME and EGMEA. Gas chromatography with a flame ionization detector was used to analyze these compounds after desorption using a mixture of methylene chloride and methanol. The arithmetic mean concentrations of EGME and EGMEA during periods of full work shifts were 2.59 ppm and 0.33 ppm, respectively. The exposure levels were lower than the Korean Ministry of Labor (MOL) OEL (5 ppm) but higher than the ACGIH TLV (0.1 ppm). In general, the working environments were poor and required much improvement, including the use of personal protective equipment. Only 50% of the workplaces had local exhaust ventilation systems in operation. The average capture velocity of the operating local exhaust ventilation systems was 0.27 m/s, which did not meet the legal requirement of 0.5 m/s. Educating workers to clearly understand the handling and use of hazardous chemicals and improving working conditions are strongly suggested.

  10. Safe antifreeze: The real difference between ethylene glycol and propylene glycol

    SciTech Connect

    Wray, T.K.

    1995-04-01

    Antifreeze-coolants are added to the radiators of internal combustion engines to prevent freezing during the winter and boil-over during the summer. Although ethylene glycol is the most commonly used coolant, products containing propylene glycol have been used--at least, experimentally--for years. Both substances have similar characteristics; however, some manufacturers claim that antifreeze-coolants containing propylene glycol are more environmentally friendly and safer to humans and animals than ethylene glycol products. This article examines these two substances, and addresses the similarities and differences of their physical and chemical compounds, thereby enabling users to determine whether such claims are valid or merely advertising hyperbole.

  11. Thermal properties of ethylene glycol aqueous solutions.

    PubMed

    Baudot, A; Odagescu, V

    2004-06-01

    Preventing ice crystallization by transforming liquids into an amorphous state, vitrification can be considered as the most suitable technique allowing complex tissues, and organs cryopreservation. This process requires the use of rapid cooling rates in the presence of cryoprotective solutions highly concentrated in antifreeze compounds, such as polyalcohols. Many of them have already been intensively studied. Their glass forming tendency and the stability of their amorphous state would make vitrification a reality if their biological toxicity did not reduce their usable concentrations often below the concentrations necessary to vitrify organs under achievable thermal conditions. Fortunately, it has been shown that mixtures of cryoprotectants tend to reduce the global toxicity of cryoprotective solutions and various efficient combinations have been proposed containing ethanediol. This work reports on the thermal properties of aqueous solutions with 40, 43, 45, 48, and 50% (w/w) of this compound measured by differential scanning calorimetry. The glass forming tendency and the stability of the amorphous state are evaluated as a function of concentration. They are given by the critical cooling rates v(ccr)above which ice crystallization is avoided, and the critical warming rates v(cwr) necessary to prevent ice crystallization in the supercooled liquid state during rewarming. Those critical rates are calculated using the same semi-empirical model as previously. This work shows a strong decrease of averaged critical cooling and warming rates when ethanediol concentration increases, V(ccr) and V(cwr) = 1.08 x 10 (10) K/min for 40% (w/w) whereas V(ccr) = 11 and V(cwr) = 853 K/min for 50% (w/w). Those results are compared with the corresponding properties of other dialcohols obtained by the same method. Ethylene glycol efficiency is between those of 1,2-propanediol and 1,3-propanediol.

  12. The aqueous photolysis of ethylene glycol adsorbed on geothite

    USGS Publications Warehouse

    Cunningham, Kirkwood M.; Goldberg, Marvin C.; Weiner, E.R.

    1985-01-01

    Suspensions of goethite (α-FeOOH) were photolyzed in aerated ethylene glycol-water solutions at pH 6.5, with ultraviolet light in the wavelength range300–400 nm. Under these conditions, formaldehyde and glycolaldehyde were detected as photoproducts. Quantum yields of formaldehyde production ranged from 1.9 7times; 10-5 to 2.9 × 10-4 over the ethylene glycol concentration range of 0.002-2.0 mol/ℓ, and gave evidence that the reaction occurred at the goethite surface. Quantum yields of glycolaldehyde were 20% less than those of formaldehyde, and displayed a concentration-dependent relationship with ethylene glycol similar to that of formaldehyde. Immediately after photolysis, Fe2+ was measured to be 4.6 × 10-7 mol/ℓ in an aerated suspension containing 1.3 mol/ℓ ethylene glycol, and 8.5 × 10-6 mol/ℓ in the corresponding deoxygenated suspension. Glycolaldehyde was not generated in the deoxygenated suspensions. These results are consistent with a mechanism involving the transfer of an electron from an adsorbed ethylene glycol molecule to an excited state of Fe3+ (Iron[III]) in the goethite lattice, to produce Fe2+ and an organic cation. In a series of reactions involving O2, FeOOH, and Fe2+, the organic cation decomposes to form formaldehyde and the intermediate radicals “OH and” CH2OH. OH reacts further with ethylene glycol in the presence of O2to yield glycolaldehyde. Aqueous photolysis of ethylene glycol sorbed onto goethite is typical of reactions that can occur in the aquatic environment.

  13. Delayed neurological sequelae from ethylene glycol, diethylene glycol and methanol poisonings.

    PubMed

    Reddy, Nandi J; Sudini, Madhuri; Lewis, Lionel D

    2010-12-01

    Ethylene glycol, diethylene glycol and methanol are widely available chemicals and are found in a variety of common household products including antifreeze, windshield washer fluid, brake fluid and lubricants. Following ingestion of these glycols and methanol, patients frequently develop an early neurological syndrome consisting of inebriation, ataxia, and if severe, seizures and coma. Though uncommon, a neurological syndrome may also develop as a delayed complication. Using Pub Med 438 references were identified of which 45 were relevant. Ethylene glycol poisoning has produced cranial nerve deficits (usually VII nerve dysfunction) after a delay of 5-20 days, Parkinsonism and cerebral edema. Diethylene glycol ingestion has been associated with the development of optic nerve injury, cranial nerve deficits, quadraparesis and peripheral neuropathy. Methanol poisoning has led to Parkinsonism and polyneuropathy. Oxalate crystal deposition likely causes the cranial neuropathies related to ethylene glycol and 2-hydroxyethoxyacetic acid is thought to be the causal moiety in cranial neuropathies resulting from diethylene glycol toxicity. Formic acid is implicated in the optic nerve damage associated with methanol. Uncommonly, delayed neurological syndromes may develop as complications of poisoning due to ethylene glycol, diethylene glycol and methanol; the onset of such neurological damage is often days or even weeks post-ingestion. Further research is required to explain why the facial nerve is the cranial nerve most commonly involved and why the basal ganglia are predisposed to injury.

  14. Massive ethylene glycol poisoning triggers osmotic demyelination syndrome.

    PubMed

    Ahmed, Azeemuddin; Tschetter, Paul A; Krasowski, Matthew D; Engelman, Amy

    2014-03-01

    Ethylene glycol is a toxic organic solvent implicated in thousands of accidental and intentional poisonings each year. Osmotic demyelination syndrome (ODS) is traditionally known as a complication of the rapid correction of hyponatremia. Our aim was to describe how patients with ethylene glycol toxicity may be at risk for developing ODS in the absence of hyponatremia. A 64-year old female patient was comatose upon presentation and laboratory results revealed an anion gap of 39, a plasma sodium of 150 mEq/L, a plasma potassium of 3.5 mEq/L, an osmolal gap of 218, an arterial blood gas pH of 7.02, whole blood lactate of 32 mEq/L, no measurable blood ethanol, and a plasma ethylene glycol concentration of 1055.5 mg/dL. The patient was treated for ethylene glycol poisoning with fomepizole and hemodialysis. Despite having elevated serum sodium levels, the patient's hospital course was complicated by ODS. Rapid changes in serum osmolality from ethylene glycol toxicity or its subsequent treatment can cause ODS independent of serum sodium levels. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Separation of parent homopolymers from polystyrene-b-poly(ethylene oxide)-b-polystyrene triblock copolymers by means of liquid chromatography: 1. comparison of different methods.

    PubMed

    Rollet, Marion; Pelletier, Bérengère; Altounian, Anaïs; Berek, Dusan; Maria, Sébastien; Beaudoin, Emmanuel; Gigmes, Didier

    2014-03-04

    Separation of parent homopolymers, polystyrene and poly(ethylene oxide), from the triblock copolymer polystyrene-b-poly(ethylene oxide)-b-polystyrene was investigated by means of liquid chromatography techniques. Overall suitability was evaluated and compared for size exclusion chromatography, (SEC), liquid chromatography under critical conditions of enthalpic interactions (LC CC), and liquid chromatography under limiting conditions of desorption (LC LCD). Among these techniques, LC LCD was the only one able to fully separate block copolymers from both their parent homopolymers in one single run. The efficiency of the separation was proven by (1)H NMR analysis of previously collected fractions.

  16. 1H-NMR characterization of poly(ethylene glycol) and polydimethylsiloxane copolymer

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

  17. Comparative acute and subchronic toxicity of ethylene glycol monopropyl ether and ethylene glycol monopropyl ether acetate

    SciTech Connect

    Katz, G.V.; Krasavage, W.J.; Terhaar, C.J.

    1984-08-01

    The acute toxicity of ethylene glycol monopropyl ether (EGPE) and ethylene-glycol monopropyl ether acetate (EGPEA) was determined in a series of standardized tests. The oral LD/sub 50/ in rats was 3089 and 9456 mg/kg EGPE and EGPEA, respectively. Skin irritation was slight following an occluded single dose application of either compound to the guinea pig abdomen. The dermal LD/sub 50/ for guinea pigs was 1 to 5 mL/kg and greater than 20 mL/kg EGPE and EGPEA, respectively. EGPE produced a very weak positive sensitization response in one of five guinea pigs. EGPE produced transient moderate to severe eye irritation in rabbits while EGPEA produced slight eye irritation. Subchronic toxicity was determined in a series of oral and inhalation studies. Groups of 10 male rats were dosed with 15, 7.5, 3.75 or 1.88 mmole/kg EGPE and 30, 15, or 7.5 mmole/kg EGPEA by gavage 5 days/week for 6 weeks. Hemoglobinuria was seen at least once at all dose levels of both compounds. EGPE had little effect on feed consumption or body weight gain, while body weight gain was reduced in the two high dose groups exposed to EGPEA and feed consumption was reduced at all dose levels. Hematologic changes were seen at all dose levels of both compounds. Absolute and/or relative spleen weights were increased at all but the lowest EGPE dose level and at all EGPEA dose levels. Gross and histopathologic examinations revealed significant effects on the spleen of animals exposed to EGPE and on the spleen, liver, kidney, and testes of animals exposed to EGPEA. Groups of 10 rats (5 M, 5 F) were exposed to 800, 400, 200 or 100 ppm EGPE or EGPEA 6 hr/day, 5 days/week for a total of 11 exposures. Body weight gains in all exposure groups were comparable to controls. 13 references, 13 figures, 9 tables.

  18. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  19. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  20. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  1. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance...

  2. 40 CFR 180.1040 - Ethylene glycol; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ethylene glycol; exemption from the... Exemptions From Tolerances § 180.1040 Ethylene glycol; exemption from the requirement of a tolerance. Ethylene glycol as a component of pesticide formulations is exempt from the requirement of a tolerance when...

  3. Direct Routes from Synthesis Gas to Ethylene Glycol.

    ERIC Educational Resources Information Center

    Dombek, B. D.

    1986-01-01

    Discusses the synthesis of ethylene glycol from carbon monoxide and hydrogen using bimetallic catalysts. Although this technology has not been implemented, it illustrates two important future trends, namely, use of bimetallic catalysts and use of coal-derived carbon monoxide and hydrogen as a new feed stock. (JN)

  4. IRIS Toxicological Review of Ethylene Glycol Mono Butyl ...

    EPA Pesticide Factsheets

    EPA has finalized the Toxicological Review of Ethylene Glycol Mono Butyl Ether: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health. N/A

  5. Direct Routes from Synthesis Gas to Ethylene Glycol.

    ERIC Educational Resources Information Center

    Dombek, B. D.

    1986-01-01

    Discusses the synthesis of ethylene glycol from carbon monoxide and hydrogen using bimetallic catalysts. Although this technology has not been implemented, it illustrates two important future trends, namely, use of bimetallic catalysts and use of coal-derived carbon monoxide and hydrogen as a new feed stock. (JN)

  6. Ethylene glycol emissions from on-road vehicles.

    PubMed

    Wood, Ezra C; Knighton, W Berk; Fortner, Ed C; Herndon, Scott C; Onasch, Timothy B; Franklin, Jonathan P; Worsnop, Douglas R; Dallmann, Timothy R; Gentner, Drew R; Goldstein, Allen H; Harley, Robert A

    2015-03-17

    Ethylene glycol (HOCH2CH2OH), used as engine coolant for most on-road vehicles, is an intermediate volatility organic compound (IVOC) with a high Henry's law coefficient. We present measurements of ethylene glycol (EG) vapor in the Caldecott Tunnel near San Francisco, using a proton transfer reaction mass spectrometer (PTR-MS). Ethylene glycol was detected at mass-to-charge ratio 45, usually interpreted as solely coming from acetaldehyde. EG concentrations in bore 1 of the Caldecott Tunnel, which has a 4% uphill grade, were characterized by infrequent (approximately once per day) events with concentrations exceeding 10 times the average concentration, likely from vehicles with malfunctioning engine coolant systems. Limited measurements in tunnels near Houston and Boston are not conclusive regarding the presence of EG in sampled air. Previous PTR-MS measurements in urban areas may have overestimated acetaldehyde concentrations at times due to this interference by ethylene glycol. Estimates of EG emission rates from the Caldecott Tunnel data are unrealistically high, suggesting that the Caldecott data are not representative of emissions on a national or global scale. EG emissions are potentially important because they can lead to the formation of secondary organic aerosol following oxidation in the atmospheric aqueous phase.

  7. Challenges in the diagnosis of ethylene glycol poisoning.

    PubMed

    McQuade, David J; Dargan, Paul I; Wood, David M

    2014-03-01

    Ethylene glycol poisoning, while uncommon, is clinically significant due to the associated risk of severe morbidity or lethality and it continues to occur in many countries around the world. The clinical presentation of ethylene glycol toxicity, while classically described in three phases, varies widely and when combined with the range of differential diagnoses that must be considered makes diagnosis challenging. Early and accurate detection is important in these patients, however, as there is a need to start antidotal treatment early to prevent serious harm. In this article, we will review the literature and provide guidance regarding the diagnosis of ethylene glycol poisoning. While gas chromatography is the gold standard, the usefulness of this test is hampered by delays in access due to availability. Consequently, there are several surrogate markers that can give an indication of ethylene glycol exposure but these must be interpreted with caution and within the clinical context. An in-depth review of these tests, particularly the detection of a raised osmolar gap or an raised anion gap acidosis, will form the main focus of this article.

  8. Ethylene Glycol Metabolism in the Acetogen Acetobacterium woodii

    PubMed Central

    Trifunović, Dragan; Schuchmann, Kai

    2016-01-01

    ABSTRACT The acetogenic bacterium Acetobacterium woodii is able to grow by the oxidation of diols, such as 1,2-propanediol, 2,3-butanediol, or ethylene glycol. Recent analyses demonstrated fundamentally different ways for oxidation of 1,2-propanediol and 2,3-butanediol. Here, we analyzed the metabolism of ethylene glycol. Our data demonstrate that ethylene glycol is dehydrated to acetaldehyde, which is then disproportionated to ethanol and acetyl coenzyme A (acetyl-CoA). The latter is further converted to acetate, and this pathway is coupled to ATP formation by substrate-level phosphorylation. Apparently, the product ethanol is in part further oxidized and the reducing equivalents are recycled by reduction of CO2 to acetate in the Wood-Ljungdahl pathway. Biochemical data as well as the results of protein synthesis analysis are consistent with the hypothesis that the propane diol dehydratase (PduCDE) and CoA-dependent propionaldehyde dehydrogenase (PduP) proteins, encoded by the pdu gene cluster, also catalyze ethylene glycol dehydration to acetaldehyde and its CoA-dependent oxidation to acetyl-CoA. Moreover, genes encoding bacterial microcompartments as part of the pdu gene cluster are also expressed during growth on ethylene glycol, arguing for a dual function of the Pdu microcompartment system. IMPORTANCE Acetogenic bacteria are characterized by their ability to use CO2 as a terminal electron acceptor by a specific pathway, the Wood-Ljungdahl pathway, enabling in most acetogens chemolithoautotrophic growth with H2 and CO2. However, acetogens are very versatile and can use a wide variety of different substrates for growth. Here we report on the elucidation of the pathway for utilization of ethylene glycol by the model acetogen Acetobacterium woodii. This diol is degraded by dehydration to acetaldehyde followed by a disproportionation to acetate and ethanol. We present evidence that this pathway is catalyzed by the same enzyme system recently described for the

  9. Ethylene Glycol Metabolism in the Acetogen Acetobacterium woodii.

    PubMed

    Trifunović, Dragan; Schuchmann, Kai; Müller, Volker

    2016-01-19

    The acetogenic bacterium Acetobacterium woodii is able to grow by the oxidation of diols, such as 1,2-propanediol, 2,3-butanediol, or ethylene glycol. Recent analyses demonstrated fundamentally different ways for oxidation of 1,2-propanediol and 2,3-butanediol. Here, we analyzed the metabolism of ethylene glycol. Our data demonstrate that ethylene glycol is dehydrated to acetaldehyde, which is then disproportionated to ethanol and acetyl coenzyme A (acetyl-CoA). The latter is further converted to acetate, and this pathway is coupled to ATP formation by substrate-level phosphorylation. Apparently, the product ethanol is in part further oxidized and the reducing equivalents are recycled by reduction of CO2 to acetate in the Wood-Ljungdahl pathway. Biochemical data as well as the results of protein synthesis analysis are consistent with the hypothesis that the propane diol dehydratase (PduCDE) and CoA-dependent propionaldehyde dehydrogenase (PduP) proteins, encoded by the pdu gene cluster, also catalyze ethylene glycol dehydration to acetaldehyde and its CoA-dependent oxidation to acetyl-CoA. Moreover, genes encoding bacterial microcompartments as part of the pdu gene cluster are also expressed during growth on ethylene glycol, arguing for a dual function of the Pdu microcompartment system. Acetogenic bacteria are characterized by their ability to use CO2 as a terminal electron acceptor by a specific pathway, the Wood-Ljungdahl pathway, enabling in most acetogens chemolithoautotrophic growth with H2 and CO2. However, acetogens are very versatile and can use a wide variety of different substrates for growth. Here we report on the elucidation of the pathway for utilization of ethylene glycol by the model acetogen Acetobacterium woodii. This diol is degraded by dehydration to acetaldehyde followed by a disproportionation to acetate and ethanol. We present evidence that this pathway is catalyzed by the same enzyme system recently described for the utilization of 1

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

    PubMed

    Liu, Di; Bielawski, Christopher W

    2016-10-01

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

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

    SciTech Connect

    Eastman, J. A.; Choi, S. U. S.; Li, S.; Yu, W.; Thompson, L. J.

    2001-02-05

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

  12. 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.

  13. Science and the perceived environmental risk from ethylene glycol and propylene glycol

    SciTech Connect

    Snellings, W.M.; Shah, S.I.; Garska, D.; Williams, J.B.

    1994-12-31

    Ethylene glycol and propylene glycol are widely used in aircraft deicing fluids (ADF), heat transfer fluids, and engine coolants. Discharges of these compounds to the environment have been reduced in recent years, but remain significant. The perceived environmental risk affects the decisions of businesses and regulatory agencies. There is a perception that propylene glycol poses a lower environmental risk than ethylene glycol. This perception is an inference from the use of low concentrations of propylene glycol in food additives -- something safe for food must be safe for fish. Environmental risk, however, must be established on the basis of scientific data, including acute and chronic toxicity to freshwater and saltwater species, oxygen demand, and persistence. A review of aquatic toxicity data for marine and freshwater species, and a review of treatability data in wastewater and soil for these widely used compounds has been completed. The data show that the two compounds, in fact, pose similar environmental risks, and in certain aspects one or the other glycol appears to be preferable. All aspects must be considered to give a valid perception of risk. The role of additives in deicing fluids is significant. Environmental fate and effect data indicate that additives are usually more toxic than the glycols, and environmental data for particular formulations must be evaluated as part of any risk assessment.

  14. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl ...

    EPA Pesticide Factsheets

    EPA has conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of ethylene glycol monobutyl ether that will appear on the Integrated Risk Information System (IRIS) database. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of propionaldehyde that will appear on the Integrated Risk Information System (IRIS) database.

  15. Effects of low temperature on the biodegradation of ethylene glycol and propylene glycol

    SciTech Connect

    Williams, J.B.; Blessing, R.L.

    1995-12-31

    Ethylene glycol and propylene glycol are used in a variety of applications. These compounds are well known to biodegrade readily at 20 C, which is the benchmark temperature for most biodegradation studies. These compounds may enter the environment when the ambient temperatures are significantly below 20 C. Biodegradation data at low temperatures was needed. For example, wintertime airport stormwater discharges contain glycols from deicing fluids. These compounds may enter streams at ambient winter temperatures, or wastewater treatment works which may be operating at temperatures well below 20 C. Biodegradation studies were conducted with BOD bottles incubated at 40 C and 10 C. Biodegradation was slower than 20 C but still significant. For ethylene glycol, the half-life (time at which one-half of the oxygen demand was consumed by the microorganisms) was 5 days at 20 C, 8 days at 10 C, and 25 days at 40 C. For propylene glycol, the half-life was 5 days at 20 C, 12 days at 10 C, and 28 days at 40 C. Two aircraft deicing fluids were also tested, and similar degradation rates were observed. This indicates the presence of additives in deicing fluids has little effect on biodegradation of glycols.

  16. Assessment of a semi-quantitative screening method for diagnosis of ethylene glycol poisoning.

    PubMed

    Sankaralingam, Arun; Thomas, Annette; James, David R; Wierzbicki, Anthony S

    2017-07-01

    Background Ethylene glycol poisoning remains a rare but important presentation to acute toxicology units. Guidelines recommended that ethylene glycol should be available as an 'urgent' test within 4 h, but these are difficult to deliver in practice. This study assessed a semi-quantitative enzymatic spectrophotometric assay for ethylene glycol compatible with automated platforms. Methods The ethylene glycol method was assessed in 21 samples from patients with an increased anion gap and metabolic acidosis not due to ethylene glycol ingestion, and seven samples known to contain ethylene glycol. All samples were analysed in random order in a blinded manner to their origin on a laboratory spectrophotometer. Results In this study, seven samples were known to contain ethylene glycol at concentrations >100 mg/L. The method correctly identified all seven samples as containing ethylene glycol. No false-positives were observed. Thirteen samples gave clear negative results. Ethylene glycol was present at <20 mg/L in one sample, but this sample remained within the limits of the negative control. Passing-Bablock correlation of estimates of ethylene glycol concentration against results obtained when the samples had been analysed using the quantitative method on an automated analyser showed a good correlation (R = 0.84) but with an apparent under-recovery. Conclusions A semi-quantitative assay for ethylene glycol was able to discriminate well between samples containing ethylene glycol and those with other causes of acidosis. It is a practical small-scale assay for rapid identification of cases of ethylene glycol poisoning.

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

    PubMed

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

    2015-03-16

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

  18. Glass transition behavior of ternary disaccharide-ethylene glycol-water solutions

    NASA Astrophysics Data System (ADS)

    Yu, Tongxu; Zhao, Lishan; Wang, Qiang; Cao, Zexian

    2017-06-01

    Glass transition behavior of ternary disaccharide-ethylene glycol-water solutions, in reference to that of the binary combinations, has been investigated towards a better understanding of their cryoprotective ability. In water-deficient solutions, the disaccharides, including trehalose, sucrose and maltose, can associate with more than 100 ethylene glycol molecules to form amorphous complex, one order of magnitude larger than the corresponding hydration numbers. In water-rich solutions, a second glass transition emerges with increasing molar fraction of ethylene glycol, indicating the possible synergy of disaccharides and ethylene glycol in vitrification of the ternary aqueous solution.

  19. Acid-base equilibria in ethylene glycol--III: selection of titration conditions in ethylene glycol medium, protolysis constants of alkaloids in ethylene glycol and its mixtures.

    PubMed

    Zikolov, P; Zikolova, T; Budevsky, O

    1976-08-01

    Theoretical titration curves are used for the selection of appropriate conditions for the acid-base volumetric determination of weak bases in ethylene glycol medium. The theoretical curves for titration of some alkaloids are deduced graphically on the basis of the logarithmic concentration diagram. The acid-base constants used for the construction of the theoretical titration curves were determined by potentiometric titration in a cell without liquid junction, equipped with a glass and a silver-silver chloride electrode. It is shown that the alkaloids investigated can be determined accurately by visual or potentiometric titration. The same approach for the selection of titration conditions seems to be applicable to other non-aqueous amphiprotic solvents.

  20. Brillouin and Raman Scattering Study of Ethylene Glycol Aqueous Solutions

    NASA Astrophysics Data System (ADS)

    Seshimo, Y.; Ike, Y.; Kojima, S.

    2008-02-01

    We studied the cluster structure of ethylene glycol aqueous solutions by Brillouin and Raman scattering. We measured the ultrasonic sound velocity of the sample by Brillouin scattering. From the concentration dependence of the sound velocity, we studied the cluster structure in the solution. We showed that the number of H2O molecule neighboring a EG molecule becomes a little higher with increasing temperature and the intermolecular interaction between EG and H2O molecules weakened with increasing temperature. In Raman scattering study, We studied the hydrogen bond in the solution using the OD stretching band. We revealed that the strength of the hydrogen bond is independent of the EG concentration.

  1. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl ...

    EPA Pesticide Factsheets

    EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from other Federal agencies and White House Offices are provided below with external peer review panel comments. EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of EGBE that will appear on the Integrated Risk Information System (IRIS) database.

  2. Ethylene glycol monomethyl ether and propylene glycol monomethyl ether: metabolism, disposition, and subchronic inhalation toxicity studies

    SciTech Connect

    Miller, R.R.; Hermann, E.A.; Young, J.T.; Landry, T.D.; Calhoun, L.L.

    1984-08-01

    Short-term and subchronic vapor inhalation studies have shown that there are pronounced differences in the toxicological properties of ethylene glycol monomethyl ether (EGME) and propylene glycol monomethyl ether (PGME). Overexposure to EGME has resulted in adverse effects on testes, bone marrow and lymphoid tissues in laboratory animals. PGME does not affect these tissues, and instead, overexposure to PGME has been associated with increases in liver weight and central nervous system depression. EGME is primarily oxidized to methoxyacetic acid in male rats, while PGME apparently undergoes O-demethylation to form propylene glycol. Since methoxyacetic acid has been shown to have the same spectrum of toxicity as EGME in male rats, the observed differences in the toxicological properties of EGME and PGME are thought to be due to the fact that the two materials are biotransformed via different routes to different types of metabolites. 6 references, 3 figures, 12 tables.

  3. Differential immunotoxicities of poly(ethylene glycol)-vs. poly(carboxybetaine)-coated nanoparticles

    PubMed Central

    Elsabahy, Mahmoud; Li, Ang; Zhang, Fuwu; Sultan, Deborah; Liu, Yongjian; Wooley, Karen L.

    2013-01-01

    Although the careful selection of shell-forming polymers for the construction of nanoparticles is an obvious parameter to consider for shielding of core materials and their payloads, providing for prolonged circulation in vivo by limiting uptake by the immune organs, and thus, allowing accumulation at the target sites, the immunotoxicities that such shielding layers elicit is often overlooked. For instance, we have previously performed rigorous in vitro and in vivo comparisons between two sets of nanoparticles coated with either non-ionic poly(ethylene glycol) (PEG) or zwitterionic poly(carboxybetaine) (PCB), but only now report the immunotoxicity and anti-biofouling properties of both polymers, as homopolymers or nanoparticle-decorating shell, in comparison to the uncoated nanoparticles, and Cremophor-EL, a well-known low molecular weight surfactant used for formulation of several drugs. It was found that both PEG and PCB polymers could induce the expression of cytokines in vitro and in vivo, with PCB being more immunotoxic than PEG, which corroborates the in vivo pharmacokineties and biodistribution profiles of the two sets of nanoparticles. This is the first study to report on the ability of PEG, the most commonly utilized polymer to coat nanomaterials, and PCB, an emerging zwitterionic anti-biofouling polymer, to induce the secretion of cytokines and be of potential immunotoxicity. Furthermore, we report here on the possible use of immunotoxicity assays to partially predict in vivo pharmacokineties and biodistribution of nanomaterials. PMID:24056145

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

    PubMed

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

    2013-12-01

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

  5. Cell attachment on poly(3-hydroxybutyrate)-poly(ethylene glycol) copolymer produced by Azotobacter chroococcum 7B.

    PubMed

    Bonartsev, Anton P; Yakovlev, Sergey G; Zharkova, Irina I; Boskhomdzhiev, Arasha P; Bagrov, Dmitrii V; Myshkina, Vera L; Makhina, Tatiana K; Kharitonova, Elena P; Samsonova, Olga V; Feofanov, Alexey V; Voinova, Vera V; Zernov, Anton L; Efremov, Yurii M; Bonartseva, Garina A; Shaitan, Konstantin V; Kirpichnikov, Michail P

    2013-05-21

    The improvement of biomedical properties, e.g. biocompatibility, of poly(3-hydroxyalkanoates) (PHAs) by copolymerization is a promising trend in bioengineering. We used strain Azotobacter chroococcum 7B, an effective producer of PHAs, for biosynthesis of not only poly(3-hydroxybutyrate) (PHB) and its main copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV), but also alternative copolymer, poly(3-hydroxybutyrate)-poly(ethylene glycol) (PHB-PEG). In biosynthesis we used sucrose as the primary carbon source and valeric acid or poly(ethylene glycol) 300 (PEG 300) as additional carbon sources. The chemical structure of PHB-PEG and PHB-HV was confirmed by 1H nuclear-magnetic resonance (1H NMR) analysis. The physico-chemical properties (molecular weight, crystallinity, hydrophilicity, surface energy) and surface morphology of films from PHB copolymers were studied. To study copolymers biocompatibility in vitro the protein adsorption and COS-1 fibroblasts growth on biopolymer films by XTT assay were analyzed. Both copolymers had changed physico-chemical properties compared to PHB homopolymer: PHB-HV and PHB-PEG had less crystallinity than PHB; PHB-HV was more hydrophobic than PHB in contrast to PHB-PEG appeared to have greater hydrophilicity than PHB; whereas the morphology of polymer films did not differ significantly. The protein adsorption to PHB-PEG was greater and more uniform than to PHB and PHB-PEG copolymer promoted better growth of COS-1 fibroblasts compared with PHB homopolymer. Thus, despite low EG-monomers content in bacterial origin PHB-PEG copolymer, this polymer demonstrated significant improvement in biocompatibility in contrast to PHB and PHB-HV copolymers, which may be coupled with increased protein adsorption and hydrophilicity of PEG-containing copolymer.

  6. Cell attachment on poly(3-hydroxybutyrate)-poly(ethylene glycol) copolymer produced by Azotobacter chroococcum 7B

    PubMed Central

    2013-01-01

    Background The improvement of biomedical properties, e.g. biocompatibility, of poly(3-hydroxyalkanoates) (PHAs) by copolymerization is a promising trend in bioengineering. We used strain Azotobacter chroococcum 7B, an effective producer of PHAs, for biosynthesis of not only poly(3-hydroxybutyrate) (PHB) and its main copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV), but also alternative copolymer, poly(3-hydroxybutyrate)-poly(ethylene glycol) (PHB-PEG). Results In biosynthesis we used sucrose as the primary carbon source and valeric acid or poly(ethylene glycol) 300 (PEG 300) as additional carbon sources. The chemical structure of PHB-PEG and PHB-HV was confirmed by 1H nuclear-magnetic resonance (1H NMR) analysis. The physico-chemical properties (molecular weight, crystallinity, hydrophilicity, surface energy) and surface morphology of films from PHB copolymers were studied. To study copolymers biocompatibility in vitro the protein adsorption and COS-1 fibroblasts growth on biopolymer films by XTT assay were analyzed. Both copolymers had changed physico-chemical properties compared to PHB homopolymer: PHB-HV and PHB-PEG had less crystallinity than PHB; PHB-HV was more hydrophobic than PHB in contrast to PHB-PEG appeared to have greater hydrophilicity than PHB; whereas the morphology of polymer films did not differ significantly. The protein adsorption to PHB-PEG was greater and more uniform than to PHB and PHB-PEG copolymer promoted better growth of COS-1 fibroblasts compared with PHB homopolymer. Conclusions Thus, despite low EG-monomers content in bacterial origin PHB-PEG copolymer, this polymer demonstrated significant improvement in biocompatibility in contrast to PHB and PHB-HV copolymers, which may be coupled with increased protein adsorption and hydrophilicity of PEG-containing copolymer. PMID:23692611

  7. [Fatal chronic oxalosis after sublethal ethylene glycol poisoning].

    PubMed

    Nizze, H; Schwabbauer, P; Brachwitz, C; Lange, H

    1997-07-01

    A 36-year-old man known as chronic alcohol abuser presently suffered from arthralgia and showed bilateral petriefied kidneys by sonography and computed tomography. Because of an unclear renal failure a kidney biopsy was performed and presented typical chronic renal oxalosis with massive oxalate crystal deposits, tubular atrophy and interstitital fibrosis. Since the man had never shown signs of hyperoxaluria in his life before, a secondary oxalosis was supposed. The subsequently prompted exploration established a three to four times abuse of rocket fuel with cola lemonade 12 years before during the patient's army time as a marine soldier. Such fuels contain ethylene glycol (glysantin) as antifreeze commonly known to cause in toxic doses acute renal tubular necrosis with hyperoxaluria. The presented case, however, suggests a rare sublethal ethylene glycol poisoning with initial renal tubular damage, oxalate crystal deposition and subsequent chronic interstitial oxalate nephritis with tubular atrophy, interstitial fibrosis and chronic renal failure. Undergoing chronic hemodialysis, the patient died 5 months after the kidney biopsy diagnosis by acute heart failure. At autopsy, progressed chronic renal oxalosis could be confirmed. Decompensated oxalate cardiomyopathy with disseminated myocardial oxalate crystal deposits caused acute heart failure promoted by myocardial hypertrophy in renal hypertension.

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

    PubMed

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

    2014-01-01

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

  9. Thermophysical properties of ethylene glycol mixture based CNT nanofluids

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  10. Five-year review of a UK 24 hour testing service for plasma ethylene glycol and diethylene glycol.

    PubMed

    Ford, Loretta T; Berg, Jonathan D

    2016-07-01

    We present a 5-year review of our UK service for plasma ethylene glycol and diethylene glycol determination in cases of acute poisoning. Ethylene glycol and diethylene glycol have been measured on all samples received for screening for toxicity by gas chromatography-flame ionization detection over a five-year period. A detailed audit of the results has been undertaken. In this period, we received 811 requests, 56% were for first-time screening and 44% repeat analysis where a positive sample has already been received. Of the first-time screen samples, 33.5% screened positive for glycol poisoning. The mean positive ethylene glycol concentration was 1204 mg/L (range 31 to 8666 mg/L). Diethylene glycol was present in 14% of ethylene glycol positive samples but never found alone. The data presented here suggest it is not essential to measure diethylene glycol since its inclusion is rarely likely to change patient management. © The Author(s) 2015.

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

    PubMed

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

    2006-08-01

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

  12. Temperature-controlled phase-transfer catalysis for ethylene glycol production from cellulose.

    PubMed

    Tai, Zhijun; Zhang, Junying; Wang, Aiqin; Zheng, Mingyuan; Zhang, Tao

    2012-07-18

    A temperature-controlled phase-transfer catalyst-tungsten acid, which in combination with a robust heterogeneous catalyst Ru/C shows a high activity and exceptional reusability for the one-pot conversion of cellulose to ethylene glycol. This binary system can be reused more than 20 times with ethylene glycol yield over 50%.

  13. On the origin of reactivity of steam reforming of ethylene glycol on supported Ni catalysts.

    PubMed

    Li, Shuirong; Zhang, Chengxi; Zhang, Peng; Wu, Gaowei; Ma, Xinbin; Gong, Jinlong

    2012-03-28

    This paper describes a strategy for producing hydrogen via steam reforming of ethylene glycol over supported nickel catalysts. Nickel plays a crucial role in conversion of ethylene glycol and production of hydrogen, while oxide supports affect product distribution of carbonaceous species. A plausible reaction pathway is proposed based on our results and the literature.

  14. 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)).

  15. Mixed micelles of lipoic acid-chitosan-poly(ethylene glycol) and distearoylphosphatidylethanolamine-poly(ethylene glycol) for tumor delivery.

    PubMed

    Elsaid, Zeeneh; Taylor, Kevin M G; Puri, Sanyogitta; Eberlein, Cath A; Al-Jamal, Khuloud; Bai, Jie; Klippstein, Rebecca; Wang, Julie Tzu-Wen; Forbes, Ben; Chana, Jasminder; Somavarapu, Satyanarayana

    2017-04-01

    Many chemotherapeutics suffer from poor aqueous solubility and tissue selectivity. Distearoylphosphatidylethanolamine-poly(ethylene glycol) (DSPE-PEG) micelles are a promising formulation strategy for the delivery of hydrophobic anticancer drugs. However, storage and in vivo instability restrict their use. The aim of this study was to prepare mixed micelles, containing a novel polymer, lipoic acid-chitosan-poly(ethylene glycol) (LACPEG), and DSPE-PEG, to overcome these limitations and potentially increase cancer cell internalisation. Drug-loaded micelles were prepared with a model tyrosine kinase inhibitor and characterized for size, surface charge, stability, morphology, drug entrapment efficiency, cell viability (A549 and PC-9 cell lines), in vivo biodistribution, ex vivo tumor accumulation and cellular internalisation. Micelles of size 30-130nm with entrapment efficiencies of 46-81% were prepared. LACPEG/DSPE-PEG mixed micelles showed greater interaction with the drug (condensing to half their size following entrapment), greater stability, and a safer profile in vitro compared to DSPE-PEG micelles. LACPEG/DSPE-PEG and DSPE-PEG micelles had similar entrapment efficiencies and in vivo tumor accumulation levels, but LACPEG/DSPE-PEG micelles showed higher tumor cell internalisation. Collectively, these findings suggest that LACPEG/DSPE-PEG mixed micelles provide a promising platform for tumor delivery of hydrophobic drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Design of smart oligo(ethylene glycol)-based biocompatible hybrid microgels loaded with magnetic nanoparticles.

    PubMed

    Boularas, Mohamed; Gombart, Emilie; Tranchant, Jean-François; Billon, Laurent; Save, Maud

    2015-01-01

    This article reports a rational strategy for preparing smart oligo(ethylene glycol)-based hybrid microgels loaded with high content of homogeneously distributed preformed magnetic nanoparticles (NPs) (up to 33 wt%). The strategy is based on the synthesis of biocompatible multiresponsive microgels by precipitation copolymerization of di(ethylene glycol) methyl ether methacrylate, oligo(ethylene glycol) methyl ether methacrylate, methacrylic acid, and oligo(ethylene glycol)diac-rylate. An aqueous dispersion of preformed magnetic NPs is straightforwardly loaded into the microgels. Robust monodisperse thermoresponsive magnetic microgels are produced, exhibiting a constant value of the volume phase transition temperature whatever the NPs content. The homogeneous microstructure of the initial stimuli-responsive biocompatible microgels plays a crucial role for the design of unique well-defined ethylene glycol-based thermoresponsive hybrid microgels. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Toxic effects of some alcohol and ethylene glycol derivatives on Cladosporium resinae.

    PubMed Central

    Lee, K H; Wong, H A

    1979-01-01

    Eleven commercially available alcohol and ethylene glycol derivatives were tested for their toxicity toward a problem organism in jet fuel, Cladosporium resinae. In the presence of glucose, 20% (vol/vol) ethylene glycol monomethyl ether prevented spore germination and mycelial growth, and 10% (vol/vol) 2-ethoxybutanol, 10% 2-isopropoxyethanol, 10% 3-methoxybutanol, 5% 2-butyloxyethanol, 5% ethylene glycol dibutyl ether, and 5% diethylene glycol monobutyl ether were found to have similar effects. In a biphasic kerosene-water system, 3-methoxybutanol, 2-butyloxyethanol, and diethylene glycol monobutyl ether were again found to be more toxic than ethylene glycol monomethyl ether. Considerable potassium efflux, protein leakage, and inhibition of endogenous respiration were observed in the presence of the more toxic compounds. 2-Butyloxyethanol also caused loss of sterols from cells. PMID:573588

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

    PubMed

    Steinbauer, Johannes; Werner, Thomas

    2017-08-10

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

  19. Membrane permeability of the human granulocyte to water, dimethyl sulfoxide, glycerol, propylene glycol and ethylene glycol.

    PubMed

    Vian, Alex M; Higgins, Adam Z

    2014-02-01

    Granulocytes are currently transfused as soon as possible after collection because they rapidly deteriorate after being removed from the body. This short shelf life complicates the logistics of granulocyte collection, banking, and safety testing. Cryopreservation has the potential to significantly increase shelf life; however, cryopreservation of granulocytes has proven to be difficult. In this study, we investigate the membrane permeability properties of human granulocytes, with the ultimate goal of using membrane transport modeling to facilitate development of improved cryopreservation methods. We first measured the equilibrium volume of human granulocytes in a range of hypo- and hypertonic solutions and fit the resulting data using a Boyle-van't Hoff model. This yielded an isotonic cell volume of 378 μm(3) and an osmotically inactive volume of 165 μm(3). To determine the permeability of the granulocyte membrane to water and cryoprotectant (CPA), cells were injected into well-mixed CPA solution while collecting volume measurements using a Coulter Counter. These experiments were performed at temperatures ranging from 4 to 37°C for exposure to dimethyl sulfoxide, glycerol, ethylene glycol, and propylene glycol. The best-fit water permeability was similar in the presence of all of the CPAs, with an average value at 21°C of 0.18 μmatm(-1)min(-1). The activation energy for water transport ranged from 41 to 61 kJ/mol. The CPA permeability at 21°C was 6.4, 1.0, 8.4, and 4.0 μm/min for dimethyl sulfoxide, glycerol, ethylene glycol, and propylene glycol, respectively, and the activation energy for CPA transport ranged between 59 and 68 kJ/mol.

  20. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  1. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  2. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  3. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether...

  4. 40 CFR 63.63 - Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Deletion of ethylene glycol monobutyl... Quantity Designations, Source Category List § 63.63 Deletion of ethylene glycol monobutyl ether from the list of hazardous air pollutants. The substance ethylene glycol monobutyl ether (EGBE,2-Butoxyethanol...

  5. Quasielastic neutron scattering and microscopic dynamics of liquid ethylene glycol

    NASA Astrophysics Data System (ADS)

    Sobolev, O.; Novikov, A.; Pieper, J.

    2007-04-01

    Quasielastic neutron scattering (QENS) by liquid ethylene glycol was analyzed using different model approaches. It was found that approximation of the QENS spectra by a set of Lorentzian functions corresponding to the translational and rotational motions produce physically unrealistic results. At the same time, the Fourier transform of the stretched-exponential function exp(-( t/ τ) β) fits the experimental data well, and results of the fit are in good agreement with those obtained earlier for other systems. The stretching parameter β was found Q independent and shows weak temperature dependence. The mean relaxation time as a function of Q departs strongly from the simple diffusion low and can be approximated by a power law < τw> = τ0Q- γ with the exponent parameter γ = 2.4.

  6. Poly(ethylene glycol) self-assembled monolayer island growth.

    PubMed

    Rundqvist, Jonas; Hoh, Jan H; Haviland, David B

    2005-03-29

    Here, we report a study of the morphology and growth dynamics of a self-assembled monolayer (SAM) of the amide containing poly(ethylene glycol) (PEG) thiol (CH3O(CH2CH2O)17NHCO(CH2)2SH) on atomically flat Au(111) surfaces. SAM growth from a 20 muM ethanolic solution reveals island growth through three distinct steps: island nucleation, island growth, and coalescence. The coalescence-step, filling voids in the SAM, is by far slowest. The fine structure study reveals dendritic island formation, an observation which can be explained by attractive intermolecular interactions and surface diffusion-limited aggregation. We have also observed a change in the island height, which peaks during the island growth phase. This height change can be associated with a molecular conformational transition.

  7. Microstructures of poly (ethylene glycol) by molding and dewetting

    NASA Astrophysics Data System (ADS)

    Suh, Kahp Y.; Langer, Robert

    2003-08-01

    We report on the fabrication of microstructures of poly (ethylene glycol) (PEG) using a soft molding technique. When a patterned poly (dimethylsiloxane) stamp is placed on a wet PEG film, the polymer in contact with the stamp spontaneously moves into the void space as a result of capillary action. Three types of microstructures are observed with the substrate surface completely exposed: a negative replica of the stamp, a two-dimensional projection of the simple cubic structure, and a two-dimensional projection of the diamond structure. A molding process is responsible for the first type and a dewetting process for the final two. A phase diagram is constructed based on the effects of molecular weight and concentration, which shows that mobility and confinement play a crucial role in determining the particular type of microstructure obtained. The PEG microstructure could be used as a lithographic resist in fabricating electronic devices and a resistant layer for preventing nonspecific adsorption of proteins or cells.

  8. Ethylene glycol contamination effects on first surface aluminized mirrors

    NASA Astrophysics Data System (ADS)

    Dunlop, Patrick; Probst, Ronald G.; Evatt, Matthew; Reddell, Larry; Sprayberry, David

    2016-07-01

    The Dark Energy Spectroscopic Instrument (DESI) is under construction for installation on the Mayall 4 Meter telescope. The use of a liquid cooling system is proposed to maintain the DESI prime focus assembly temperature within ±1°C of ambient. Due to concerns of fluid deposition onto optical surfaces from possible leaks, systematic tests were performed of the effects on first surface aluminized mirrors of ethylene glycol and two other candidate coolants. Objective measurement of scattering and reflectivity was an important supplement to visual inspection. Rapid cleanup of a coolant spill followed by a hand wash of the mirror limited surface degradation to the equivalent of a few months of general environmental exposure. Prolonged exposure to corrosive coolants dissolved the aluminum, necesitating mirror recoating.

  9. Magnetic fluid poly(ethylene glycol) with moderate anticancer activity

    NASA Astrophysics Data System (ADS)

    Závišová, Vlasta; Koneracká, Martina; Múčková, Marta; Lazová, Jana; Juríková, Alena; Lancz, Gábor; Tomašovičová, Natália; Timko, Milan; Kováč, Jozef; Vávra, Ivo; Fabián, Martin; Feoktystov, Artem V.; Garamus, Vasil M.; Avdeev, Mikhail V.; Kopčanský, Peter

    2011-05-01

    Poly(ethylene glycol) (PEG)-containing magnetic fluids - magnetite (Fe 3O 4) stabilized by sodium oleate - were prepared. Magnetic measurements confirmed superparamagnetic behaviour at room temperature. The structure of that kind of magnetic fluid was characterized using different techniques, including electron microscopy, photon cross correlation spectroscopy and small-angle neutron scattering, while the adsorption of PEG on magnetic particles was analyzed by differential scanning calorimetry and Fourier transform infrared spectroscopy. From the in vitro toxicity tests it was found that a magnetic fluid containing PEG (MFPEG) partially inhibited the growth of cancerous B16 cells at the highest tested dose (2.1 mg/ml of Fe 3O 4 in MFPEG).

  10. Rheological profile of boron nitride–ethylene glycol nanofluids

    SciTech Connect

    Żyła, Gaweł; Witek, Adam; Gizowska, Magdalena

    2015-01-07

    The paper presents the complete rheological profile of boron nitride (BN)–ethylene glycol (EG) nanofluids. Nanofluids have been produced by two-step method on the basis of commercially available powder of plate-like grains of nanometrical thickness. Viscoelastic structure has been determined in oscillatory measurements at a constant frequency and temperature. Viscosity and flow curves for these materials have been measured. Studies have shown that the Carreau model can be used for the modeling of dynamic viscosity curves of the material. The samples were tested for the presence of thixotropy. The dependence of viscosity on temperature was also examined. The effect of temperature on the dynamic viscosity of BN-EG nanofluids can be modelled with the use of Vogel-Fulcher-Tammann expression.

  11. 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

    2001-09-04

    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.

  12. 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.

  13. 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.

  14. Ethylene glycol-assisted coating of titania on nanoparticles.

    PubMed

    Dahl, Michael; Castaneda, Fernando; Joo, Ji Bong; Reyes, Victor; Goebl, James; Yin, Yadong

    2016-06-14

    Coating titania shells onto sub-micron sized particles has been widely studied recently, with success mainly limited to objects with sizes above 50 nm. Direct coating on particles below this size has been difficult to attain especially with good control over properties such as thickness and crystallinity. Here we demonstrate that titanium-glycolate formed by reacting titanium alkoxide and ethylene glycol is an excellent precursor for coating titania on aqueous nanoparticles. The new coating method is particularly useful for its ability to coat materials lacking strong polymers or ligands which are frequently needed to facilitate typical titania coatings. We demonstrate the effectiveness of the process of coating titania on metal nanoparticles ranging from citrate-stabilized gold and silver spheres to gold nanorods and silver nanoplates, and larger particles such as SiO2 microspheres and polymer spheres. Further the thickness of these coatings can be tuned from a few nanometers to ∼40 nm through sequential coatings. These coatings can subsequently be crystallized into TiO2 through refluxing in water or by calcination to obtain crystalline shells. This procedure can be very useful for the production of TiO2 coatings with tunable thickness and crystallinity as well as for further study on the effect of TiO2 coatings on nanoparticles.

  15. Surface Mechanical and Rheological Behaviors of Biocompatible Poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) and Poly((D,L-lactic acid-ran-glycolic acid-ran-ε-caprolactone)-block-ethylene glycol) (PLGACL-PEG) Block Copolymers at the Air-Water Interface

    SciTech Connect

    Kim, Hyun Chang; Lee, Hoyoung; Khetan, Jawahar; Won, You-Yeon

    2016-02-01

    Air–water interfacial monolayers of poly((d,l-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA–PEG) exhibit an exponential increase in surface pressure under high monolayer compression. In order to understand the molecular origin of this behavior, a combined experimental and theoretical investigation (including surface pressure–area isotherm, X-ray reflectivity (XR) and interfacial rheological measurements, and a self-consistent field (SCF) theoretical analysis) was performed on air–water monolayers formed by a PLGA–PEG diblock copolymer and also by a nonglassy analogue of this diblock copolymer, poly((d,l-lactic acid-ran-glycolic acid-ran-caprolactone)-block-ethylene glycol) (PLGACL–PEG). The combined results of this study show that the two mechanisms, i.e., the glass transition of the collapsed PLGA film and the lateral repulsion of the PEG brush chains that occur simultaneously under lateral compression of the monolayer, are both responsible for the observed PLGA–PEG isotherm behavior. Upon cessation of compression, the high surface pressure of the PLGA–PEG monolayer typically relaxes over time with a stretched exponential decay, suggesting that in this diblock copolymer situation, the hydrophobic domain formed by the PLGA blocks undergoes glass transition in the high lateral compression state, analogously to the PLGA homopolymer monolayer. In the high PEG grafting density regime, the contribution of the PEG brush chains to the high monolayer surface pressure is significantly lower than what is predicted by the SCF model because of the many-body attraction among PEG segments (referred to in the literature as the “n-cluster” effects). The end-grafted PEG chains were found to be protein resistant even under the influence of the “n-cluster” effects.

  16. Surface Mechanical and Rheological Behaviors of Biocompatible Poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) and Poly((D,L-lactic acid-ran-glycolic acid-ran-ε-caprolactone)-block-ethylene glycol) (PLGACL-PEG) Block Copolymers at the Air-Water Interface.

    PubMed

    Kim, Hyun Chang; Lee, Hoyoung; Khetan, Jawahar; Won, You-Yeon

    2015-12-29

    Air-water interfacial monolayers of poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) exhibit an exponential increase in surface pressure under high monolayer compression. In order to understand the molecular origin of this behavior, a combined experimental and theoretical investigation (including surface pressure-area isotherm, X-ray reflectivity (XR) and interfacial rheological measurements, and a self-consistent field (SCF) theoretical analysis) was performed on air-water monolayers formed by a PLGA-PEG diblock copolymer and also by a nonglassy analogue of this diblock copolymer, poly((D,L-lactic acid-ran-glycolic acid-ran-caprolactone)-block-ethylene glycol) (PLGACL-PEG). The combined results of this study show that the two mechanisms, i.e., the glass transition of the collapsed PLGA film and the lateral repulsion of the PEG brush chains that occur simultaneously under lateral compression of the monolayer, are both responsible for the observed PLGA-PEG isotherm behavior. Upon cessation of compression, the high surface pressure of the PLGA-PEG monolayer typically relaxes over time with a stretched exponential decay, suggesting that in this diblock copolymer situation, the hydrophobic domain formed by the PLGA blocks undergoes glass transition in the high lateral compression state, analogously to the PLGA homopolymer monolayer. In the high PEG grafting density regime, the contribution of the PEG brush chains to the high monolayer surface pressure is significantly lower than what is predicted by the SCF model because of the many-body attraction among PEG segments (referred to in the literature as the "n-cluster" effects). The end-grafted PEG chains were found to be protein resistant even under the influence of the "n-cluster" effects.

  17. Poly(ethylene glycol)-poly(L-lactide) diblock copolymer prevents aggregation of poly(L-lactide) microspheres during ethylene oxide gas sterilization.

    PubMed

    Choi, Y; Kim, S Y; Moon, M H; Kim, S H; Lee, K S; Byun, Y

    2001-05-01

    Sterilization procedure is one of the most important obstacles in the clinical applications of biodegradable microspheres. The microspheres prepared with poly(alpha-hydroxy acid) were severely aggregated during ethylene oxide (EO) gas sterilization, and could not be used in clinical applications. In this study, the effects of EO gas sterilization on the poly(L-lactide) (PLLA) microspheres were analyzed by nuclear magnetic resonance spectroscopy (1H-NMR), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), scanning electron microscope (SEM) and size fractionation. The aggregation between the microspheres might be stimulated by high mobility of amorphous regions of PLLA on the microsphere surfaces since both water vapor and gas mixture can reduce glass transition temperature (Tg) of PLLA below the sterilization temperature. During EO gas sterilization, there were no changes in the molecular structure and the molecular weight of PLLA in microspheres, but there were changes in the crystallinity of PLLA in microspheres. In this study, poly(L-lactide)-poly(ethylene glycol) diblock copolymers (PLE) were blended with PLLA homopolymers in various ratios to design the microsphere suitable for EO gas sterilization. Aggregation of PLLA microspheres was markedly prevented when more than 4wt% of PLE was blended in the microspheres. This inhibition effect on aggregation may be due to the increased initial crystallinity of the microspheres, which help to maintain the microsphere morphology during EO gas sterilization.

  18. Anaerobic Biodegradation of Ethylene Glycol within Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  19. Ethylene glycol emissions from on-road vehicles: implications for aqueous phase secondary organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Wood, E. C.; Knighton, W. B.; Fortner, E.; Herndon, S. C.; Onasch, T. B.; Franklin, J.; Harley, R. A.; Gentner, D. R.; Goldstein, A. H.

    2012-12-01

    Ethylene glycol (HOCH2CH2OH), used as an engine coolant for most on-road vehicles, is an intermediate volatility organic compound (IVOC) with a high Henry's Law Coefficient (kH > 10,000 M atm-1) . Oxidation of ethylene glycol, especially in the atmospheric aqueous phase (clouds, fog, wet aerosol), can lead to the formation of glycolaldehyde, oxalic acid, and ultimately secondary organic aerosol. We present measurements of unexpectedly high ethylene glycol emissions in the Caldecott Tunnel near San Francisco (Summer 2010) and the Washburn Tunnel near Houston (Spring 2009). Ethylene glycol was detected using a proton-transfer reaction mass spectrometer (PTR-MS) at m/z = 45, which is usually interpreted as acetaldehyde. Although not necessarily a tailpipe emission, effective fuel-based emission factors are calculated using the carbon balance method and range from 50 to 400 mg ethylene glycol per kg fuel. Total US and global emissions are estimated using these emission factors and fuel consumption rates and are compared to previous model estimates of ethylene glycol emissions (e.g., the Regional Atmospheric Chemistry Model). Compared to biogenically emitted isoprene, ethylene glycol is likely a minor source of glycolaldehyde globally, but may contribute significantly to glycolaldehyde, oxalate and SOA formation in areas dominated by urban emissions.

  20. Recent progress in alkaline direct ethylene glycol fuel cells for sustainable energy production

    NASA Astrophysics Data System (ADS)

    An, L.; Chen, R.

    2016-10-01

    Alkaline direct ethylene glycol fuel cells are one of the most promising power sources for portable, mobile and stationary power applications, primarily because this type of fuel cell runs on a sustainable fuel and the key materials that constitute the fuel cell are relatively inexpensive. This review article summarizes and discusses the past investigations on the development of alkaline direct ethylene glycol fuel cells, including the physical and chemical processes through the fuel cell structure, the electrocatalytic oxidation and electrocatalysts of ethylene glycol, the singe-cell performance, and innovative system designs.

  1. An enzymatic assay for the detection of glycolic acid in serum as a marker of ethylene glycol poisoning.

    PubMed

    Hanton, Sally L; Watson, Ian D

    2013-12-01

    Ingestion of ethylene glycol is a relatively rare event but one with potentially lethal consequences. Early diagnosis and appropriate treatment are essential. However, diagnosis of poisoning can only be confirmed definitively by the measurement of ethylene glycol and/or its metabolites, usually performed by gas chromatographic methods. These methods are complex, requiring specialized equipment and expertise, and are often not available on an emergency basis. A quick, simple, and inexpensive enzymatic assay has been developed to detect glycolic acid, the major metabolite of ethylene glycol and the main cause of the resulting metabolic acidosis. In this assay, glycolic acid is converted to glyoxylic acid by glycolate oxidase, with the production of hydrogen peroxide, which is converted to a quinoneimine dye for spectrophotometric detection. The assay has a functional sensitivity of 26 mg/L and coefficients of variation less than 13% (interassay) and less than 10% (intra-assay). No significant interference was observed for a range of compounds, and a comparison with a gas chromatography-mass spectrometry method gave clinical sensitivity of 86% and clinical specificity of 92%. Stability of enzyme solutions was increased by the use of an alternative buffer, in which greater than 90% of the original activity was retained after storage at -20°C. As ethylene glycol poisoning is a medical emergency, there is a need for a screening test to minimize delays in diagnosis. The assay we describe is a simple and effective way to detect ethylene glycol poisoning, enabling earlier initiation of appropriate therapy and improving patient outcomes.

  2. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (External Review Draft)

    EPA Science Inventory

    EPA has conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of ethylene glycol monobutyl ether that will appear on the Integrated Risk Information System (IRIS) database.

  3. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (External Review Draft)

    EPA Science Inventory

    EPA has conducted a peer review of the scientific basis supporting the human health hazard and dose-response assessment of ethylene glycol monobutyl ether that will appear on the Integrated Risk Information System (IRIS) database.

  4. Novel antifouling oligo(ethylene glycol) methacrylate particles via surfactant-free emulsion polymerization.

    PubMed

    Buyukserin, Fatih; Camli, Sevket Tolga; Yavuz, Mustafa Selman; Budak, Gurer Guven

    2011-03-01

    The use of particle formulations with antifouling surface properties attracts increasing interest in several biotechnological applications. Majority of these studies utilize a poly(ethylene glycol) coating to render the corresponding surface nonrecognizable to biological macromolecules. Herein, we report a simple way to prepare novel antifouling colloids composed of oligo(ethylene glycol) backbones via surfactant-free emulsion polymerization. Monodisperse cross-linked poly(ethylene glycol) ethyl ether methacrylate particles were characterized by dynamic light scattering and transmission electron microscopy. The effects of monomer, cross-linker and initiator on particle characteristics were investigated. More importantly, a prominent blockage of bovine serum albumin adsorption was obtained for the poly(ethylene glycol)-based sub-micron (~200 nm) particles when compared with similar-sized poly(methyl methacrylate) counterparts.

  5. Protective Effect of Propolis in Proteinuria, Crystaluria, Nephrotoxicity and Hepatotoxicity Induced by Ethylene Glycol Ingestion.

    PubMed

    El Menyiy, Nawal; Al Waili, Noori; Bakour, Meryem; Al-Waili, Hamza; Lyoussi, Badiaa

    2016-10-01

    Propolis is a natural honeybee product with wide biological activities and potential therapeutic properties. The aim of the study is to evaluate the protective effect of propolis extract on nephrotoxicity and hepatotoxicity induced by ethylene glycol in rats. Five groups of rats were used. Group 1 received drinking water, group 2 received 0.75% ethylene-glycol in drinking water, group 3 received 0.75% ethylene-glycol in drinking water along with cystone 500 mg/kg/body weight (bw) daily, group 4 received 0.75% ethylene-glycol in drinking water along with propolis extract at a dose of 100 mg/kg/bw daily, and group 5 received 0.75% ethylene-glycol in drinking water along with propolis extract at a dose of 250 mg/kg/bw daily. The treatment continued for a total of 30 d. Urinalyses for pH, crystals, protein, creatinine, uric acid and electrolytes, and renal and liver function tests were performed. Ethylene-glycol increased urinary pH, urinary volume, and urinary calcium, phosphorus, uric acid and protein excretion. It decreased creatinine clearance and magnesium and caused crystaluria. Treatment with propolis extract or cystone normalized the level of magnesium, creatinine, sodium, potassium and chloride. Propolis is more potent than cystone. Propolis extract alleviates urinary protein excretion and ameliorates the deterioration of liver and kidney function caused by ethylene glycol. Propolis extract has a potential protective effect against ethylene glycol induced hepatotoxicity and nephrotoxicity and has a potential to treat and prevent urinary calculus, crystaluria and proteinuria. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

  6. The Synthesis of α-MoO₃ by Ethylene Glycol.

    PubMed

    Chiang, Tzu Hsuan; Yeh, Hung Che

    2013-10-17

    This study investigated the use of ethylene glycol to form α-MoO₃ (molybdenum trioxide) from ammonium molybdate tetrahydrate at various sintering temperatures for 1 h. During the sintering process, the morphologies of the constituents were observed using scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy was used to explain the reaction process. In this work, the results obtained using X-ray photoelectron spectroscopy (XRD) demonstrated that, when the molybdenum trioxide powder was treated thermally at 300 °C, the material exhibited crystallinity. The peaks were indexed to correspond with the (110), (040), (021), (111), and (060) crystallographic planes, and the lattice parameters of a, b, and c were about 3.961, 13.876, and 3.969 Å. Using these observations, we confirmed that orthorhombic α-MoO₃ was formed for sintering temperatures from 300 to 700 °C. Pattern images were obtained by the selected area electron diffraction pattern (SAED) technique, and the d distance of the high resolution transmission electron microscopy (HRTEM) images were almost 0.39 and 0.36 nm, and the Mo 3d5/2, Mo 3d3/2, and O 1s of X-ray photoelectron spectroscopy (XPS) were located at 233.76, 237.03, and 532.19 eV, which also demonstrated that α-MoO₃ powder had been synthesized.

  7. Clinical Features of Reported Ethylene Glycol Exposures in the United States

    PubMed Central

    Jobson, Meghan A.; Hogan, Susan L.; Maxwell, Colin S.; Hu, Yichun; Hladik, Gerald A.; Falk, Ronald J.; Beuhler, Michael C.; Pendergraft, William F.

    2015-01-01

    Background Ethylene glycol is highly toxic and represents an important cause of poisonings worldwide. Toxicity can result in central nervous system dysfunction, cardiovascular compromise, elevated anion gap metabolic acidosis and acute kidney injury. Many states have passed laws requiring addition of the bittering agent, denatonium benzoate, to ethylene glycol solutions to reduce severity of exposures. The objectives of this study were to identify differences between unintentional and intentional exposures and to evaluate the utility of denatonium benzoate as a deterrent. Methods and Findings Using the National Poison Data System, we performed a retrospective analysis of reported cases of ethylene glycol exposures from January 2006 to December 2013. Outcome classification was summed for intentionality and used as a basis for comparison of effect groups. There were 45,097 cases of ethylene glycol exposures resulting in 154 deaths. Individuals more likely to experience major effects or death were older, male, and presented with more severe symptoms requiring higher levels of care. Latitude and season did not correlate with increased exposures; however, there were more exposures in rural areas. Denatonium benzoate use appeared to have no effect on exposure severity or number. Conclusion Deaths due to ethylene glycol exposure were uncommon; however, there were major clinical effects and more exposures in rural areas. Addition of denatonium benzoate was not associated with a reduction in exposures. Alternative means to deter ingestion are needed. These findings suggest the need to consider replacing ethylene glycol with alternative and less toxic agents. PMID:26566024

  8. Clinical Features of Reported Ethylene Glycol Exposures in the United States.

    PubMed

    Jobson, Meghan A; Hogan, Susan L; Maxwell, Colin S; Hu, Yichun; Hladik, Gerald A; Falk, Ronald J; Beuhler, Michael C; Pendergraft, William F

    2015-01-01

    Ethylene glycol is highly toxic and represents an important cause of poisonings worldwide. Toxicity can result in central nervous system dysfunction, cardiovascular compromise, elevated anion gap metabolic acidosis and acute kidney injury. Many states have passed laws requiring addition of the bittering agent, denatonium benzoate, to ethylene glycol solutions to reduce severity of exposures. The objectives of this study were to identify differences between unintentional and intentional exposures and to evaluate the utility of denatonium benzoate as a deterrent. Using the National Poison Data System, we performed a retrospective analysis of reported cases of ethylene glycol exposures from January 2006 to December 2013. Outcome classification was summed for intentionality and used as a basis for comparison of effect groups. There were 45,097 cases of ethylene glycol exposures resulting in 154 deaths. Individuals more likely to experience major effects or death were older, male, and presented with more severe symptoms requiring higher levels of care. Latitude and season did not correlate with increased exposures; however, there were more exposures in rural areas. Denatonium benzoate use appeared to have no effect on exposure severity or number. Deaths due to ethylene glycol exposure were uncommon; however, there were major clinical effects and more exposures in rural areas. Addition of denatonium benzoate was not associated with a reduction in exposures. Alternative means to deter ingestion are needed. These findings suggest the need to consider replacing ethylene glycol with alternative and less toxic agents.

  9. Chemocatalytic Conversion of Cellulosic Biomass to Methyl Glycolate, Ethylene Glycol, and Ethanol.

    PubMed

    Xu, Gang; Wang, Aiqin; Pang, Jifeng; Zhao, Xiaochen; Xu, Jinming; Lei, Nian; Wang, Jia; Zheng, Mingyuan; Yin, Jianzhong; Zhang, Tao

    2017-04-10

    Production of chemicals and fuels from renewable cellulosic biomass is important for the creation of a sustainable society, and it critically relies on the development of new and efficient transformation routes starting from cellulose. Here, a chemocatalytic conversion route from cellulosic biomass to methyl glycolate (MG), ethylene glycol (EG), and ethanol (EtOH) is reported. By using a tungsten-based catalyst, cellulose is converted into MG with a yield as high as 57.7 C % in a one-pot reaction in methanol at 240 °C and 1 MPa O2 , and the obtained MG can be easily separated by distillation. Afterwards, it can be nearly quantitatively converted to EG at 200 °C and to EtOH at 280 °C with a selectivity of 50 % through hydrogenation over a Cu/SiO2 catalyst. By this approach, the fine chemical MG, the bulk chemical EG, and the fuel additive EtOH can all be efficiently produced from renewable cellulosic materials, thus providing a new pathway towards mitigating the dependence on fossil resources. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    PubMed

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

    2013-01-01

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

  11. Dehydration and dehydrogenation of ethylene glycol on rutile TiO2(110).

    PubMed

    Li, Zhenjun; Kay, Bruce D; Dohnálek, Zdenek

    2013-08-07

    The interactions of ethylene glycol with a partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one ethylene glycol per two Ti sites. Most of the adsorbed ethylene glycol (∼80%) undergoes further reactions to yield other products. Two major channels are observed, dehydration yielding ethylene and water and dehydrogenation yielding acetaldehyde and hydrogen. Hydrogen formation is rather surprising as it has not been observed previously on TiO2(110) from simple organic molecules. The coverage dependent yields of ethylene and acetaldehyde correlate well with those of water and hydrogen, respectively. Dehydration dominates at lower ethylene glycol coverages (<0.2 ML) and plateaus as the coverage is increased to saturation. Dehydrogenation is observed primarily at higher ethylene glycol coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.

  12. Synthesis of Monodispersed Tantalum(V) oxide Nanospheres by an Ethylene Glycol Mediated Route

    EPA Science Inventory

    Tantalum(V) oxide (Ta2O5) nanospheres have been synthesized by a very simple ethylene glycol mediated route. The two-step process involves the formation of glycolate nanoparticles and their subsequent hydrolysis and calcination to generate the final Ta2O5 nanospheres. The synthes...

  13. Synthesis of Monodispersed Tantalum(V) oxide Nanospheres by an Ethylene Glycol Mediated Route

    EPA Science Inventory

    Tantalum(V) oxide (Ta2O5) nanospheres have been synthesized by a very simple ethylene glycol mediated route. The two-step process involves the formation of glycolate nanoparticles and their subsequent hydrolysis and calcination to generate the final Ta2O5 nanospheres. The synthes...

  14. Synthesis and characterization of hydrolytically degradable copolyester biomaterials based on glycolic acid, sebacic acid and ethylene glycol.

    PubMed

    Simitzis, J; Soulis, S; Triantou, D; Zoumpoulakis, L; Zotali, P

    2011-12-01

    Copolyesters of glycolic acid (G) combined with sebacic acid (S) and ethylene glycol were synthesized in different molar ratios (G: 0-100% and S: 100-0%) and their hydrolytic degradation was studied and correlated with their structures. Based on the FTIR spectra of the homopolyesters and copolyesters and the normalized peak intensity of the I(2918), I(2848) and I(1087) for the corresponding wavenumbers, it is concluded that the I(2918) and the I(2848) are in accordance with the mean number degree of polymerization of ethylene sebacate units and the I(1087) is in accordance with the mean number degree of polymerization of glycolate units. Based on the XRD diffractograms, poly(ethylene sebacate) and poly(glycolic acid) belong to the monoclinic and the orthorhombic crystal system, respectively and both have higher crystallinity than the copolyesters. The experimental data of the hydrolytic degradation were fitted with exponential rise to maximum type functions using two-parameter model and four-parameter model. Three regions can been distinguished for the hydrolytic degradation by decreasing the molar feed ratio of sebacic acid, which are correlated with the changes of crystallinity. Two copolyesters are proposed: first the copolyester with high amount of glycolate units (S10G90) having higher hydrolytic degradation than G100 and second the copolyester with equal amount of glycolate and ethylene sebacate units (S50G50), having lower hydrolytic degradation than G100. These hydrolytically degradable copolyesters are soluble in common organic solvents, opposite to poly(glycolic acid) and could have perspectives for biomedical applications.

  15. Phenolic Polymer Solvation in Water and Ethylene Glycol II: Ab Initio Computations.

    PubMed

    Bauschlicher, Charles W; Bucholz, Eric W; Haskins, Justin B; Monk, Joshua D; Lawson, John W

    2017-03-14

    Ab initio techniques are used to study the interaction of ethylene glycol and water with phenolic polymer. The water bonds more strongly with the phenolic OH than with the ring. The phenolic OH groups can form hydrogen bonds between themselves. For more than one water molecule, there is a competition between water-water and water-phenolic interactions. Ethylene glycol shows the same effects as water, but the potential energy surface is further complicated by CH$_2$-phenolic interactions, different conformers of ethylene glycol and two OH groups on each molecule. Thus the ethylene glycol-phenolic potential is more complicated than is the water-phenolic potential. The results of the {\\it ab initio} calculations are compared to those obtained using a force field. These calibration studies show that the water system is easier to describe than the ethylene glycol system. The calibrations studies confirm the reliability of force fields used in our companion molecular dynamics study of a phenolic polymer in water and ethylene solutions.

  16. Heat-transfer tests of aqueous ethylene glycol solutions in an electrically heated tube

    NASA Technical Reports Server (NTRS)

    Bernardo, Everett; Eian, Carroll S

    1945-01-01

    As part of an investigation of the cooling characteristics of liquid-cooled engines, tests were conducted with an electrically heated single-tube heat exchanger to determine the heat-transfer characteristics of an-e-2 ethylene glycol and other ethylene glycol-water mixtures. Similar tests were conducted with water and commercial butanol (n-butyl alcohol) for check purposes. The results of tests conducted at an approximately constant liquid-flow rate of 0.67 pound per second (Reynolds number, 14,500 to 112,500) indicate that at an average liquid temperature 200 degrees f, the heat-transfer coefficients obtained using water, nominal (by volume) 30 percent-70 percent and 70 percent-30 percent glycol-water mixtures are approximately 3.8, 2.8, and 1.4 times higher, respectively, than the heat-transfer coefficients obtained using an-e-2 ethylene glycol.

  17. Noncovalent adducts of poly(ethylene glycols) with proteins.

    PubMed

    Topchieva, I N; Sorokina, E M; Efremova, N V; Ksenofontov, A L; Kurganov, B I

    2000-01-01

    A new method of preparation of noncovalent complexes between poly(ethylene glycol) (PEG) and proteins (alpha-chymotrypsin (ChT), lysozyme, bovine serum albumine) under high pressure has been developed. The involvement of polymer in the complexes was proved using (3)H-labeled PEG. The composition of the complexes (the number of polymer chains per one ChT molecule) depends on the molecular mass of PEG and decreases with the increase in molecular mass from 300 to 4000, whereas the portion of the protein (wt %) in complexes does not depend on the molecular mass of incorporated PEG and corresponds to approximately 70 wt %. The kinetic constants for enzymatic hydrolysis of N-benzoyl-L-tyrosine ethyl ester and azocasein catalyzed by the PEG-ChT complexes are identical with the corresponding values for the native ChT. According to the data obtained by the method of circular dichroism, the enzyme in the complexes fully retains its secondary structure. The steric availability of PEG polymer chains in the complexes was evaluated by their complexation with alpha-cyclodextrin (CyD) or polymer derivatives of beta-CyD modified with PEG (PEG-beta-CyD). In contrast to free PEG, only part of PEG polymer chains ( approximately 10%) interact with alpha-CyD. Thus, the complexation of PEG with ChT proceeds by means of multipoint interaction with surface groups of the protein globule located far from the active site and results in the sufficient decrease in the availability of polymer chains. The complexes between PEG chains in PEG-protein adducts and PEG-beta-CyD may be considered as a novel type of dendritic structures.

  18. Ethylene glycol induces hyperoxaluria without metabolic acidosis in rats.

    PubMed

    Green, Mike L; Hatch, Marguerite; Freel, Robert W

    2005-09-01

    Ethylene glycol (EG) consumption is commonly employed as an experimental regimen to induce hyperoxaluria in animal models of calcium oxalate nephrolithiasis. This approach has, however, been criticized because EG overdose induces metabolic acidosis in humans. We tested the hypothesis that EG consumption (0.75% in drinking water for 4 wk) induces metabolic acidosis by comparing arterial blood gases, serum electrolytes, and urinary chemistries in five groups of Sprague-Dawley rats: normal controls (CON), those made hyperoxaluric (HYP) with EG administration, unilaterally nephrectomized controls (UNI), unilaterally nephrectomized rats fed EG (HRF), and a metabolic acidosis (MA) reference group imbibing sweetened drinking water (5% sucrose) containing 0.28 M NH4Cl. Arterial pH, plasma bicarbonate concentrations, anion gap, urinary pH, and the excretion of titratable acid, ammonium, phosphate, citrate, and calcium in HYP rats were not significantly different from CON rats, indicating that metabolic acidosis did not develop in HYP rats with two kidneys. Unilateral nephrectomy alone (UNI group) did not significantly affect arterial pH, plasma bicarbonate, anion gap, or urinary pH compared with CON rats; however, HRF rats exhibited some signs of a nascent acidosis in having an elevated anion gap, higher phosphate excretion, lower urinary pH, and an increase in titratable acid. Frank metabolic acidosis was observed in the MA rats: decreased arterial pH and plasma HCO3(-) concentration with lower urinary pH and citrate excretion with elevated excretion of ammonium, phosphate and, hence, titratable acid. We conclude that metabolic acidosis does not develop in conventional EG treatments but may ensue with renal insufficiency resulting from an oxalate load.

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

    PubMed

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

    2014-03-28

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

  20. Cryopreservation of mouse embryos by ethylene glycol-based vitrification.

    PubMed

    Mochida, Keiji; Hasegawa, Ayumi; Taguma, Kyuichi; Yoshiki, Atsushi; Ogura, Atsuo

    2011-11-18

    Cryopreservation of mouse embryos is a technological basis that supports biomedical sciences, because many strains of mice have been produced by genetic modifications and the number is consistently increasing year by year. Its technical development started with slow freezing methods in the 1970s(1), then followed by vitrification methods developed in the late 1980s(2). Generally, the latter technique is advantageous in its quickness, simplicity, and high survivability of recovered embryos. However, the cryoprotectants contained are highly toxic and may affect subsequent embryo development. Therefore, the technique was not applicable to certain strains of mice, even when the solutions are cooled to 4°C to mitigate the toxic effect during embryo handling. At the RIKEN BioResource Center, more than 5000 mouse strains with different genetic backgrounds and phenotypes are maintained(3), and therefore we have optimized a vitrification technique with which we can cryopreserve embryos from many different strains of mice, with the benefits of high embryo survival after vitrifying and thawing (or liquefying, more precisely) at the ambient temperature(4). Here, we present a vitrification method for mouse embryos that has been successfully used at our center. The cryopreservation solution contains ethylene glycol instead of DMSO to minimize the toxicity to embryos(5). It also contains Ficoll and sucrose for prevention of devitrification and osmotic adjustment, respectively. Embryos can be handled at room temperature and transferred into liquid nitrogen within 5 min. Because the original method was optimized for plastic straws as containers, we have slightly modified the protocol for cryotubes, which are more easily accessible in laboratories and more resistant to physical damages. We also describe the procedure of thawing vitrified embryos in detail because it is a critical step for efficient recovery of live mice. These methodologies would be helpful to researchers and

  1. Glycolaldehyde and Ethylene Glycol on Nearly Isotropic Comets

    NASA Astrophysics Data System (ADS)

    Butler, Jayden; Zellner, Nicolle; McCaffrey, Vanessa

    2017-01-01

    The delivery of glycolaldehyde (GLA) and ethylene glycol (EG) could be could be important for understanding the origin of life. GLA, the simplest sugar, is a building block for ribose, the backbone of RNA; EG is a reduced alcohol variant of GLA, found to be created by the impact of GLA under simulated cometary impact conditions (McCaffrey et al. 2014). GLA and EG have been found in regions of the interstellar medium and recently on nearly isotropic comets (NICs), which originate in the Oort Cloud. NICs are long period comets (P > 200 years) and have orbits that are nearly randomly inclined to the ecliptic plane (Mumma & Charnley et al. 2011). Based on impact experiments that assess survivability of these molecules (McCaffrey et al. 2014), we aim to determine the mass of GLA and EG that could have been delivered on comets since the formation of the Solar System. The focus of the current study is to determine the abundances of GLA and EG on C/1995 O1 (Hale-Bopp), C/2012 F6 (Lemmon), C/2013 R1 (Lovejoy 2013), and C/2014 Q2 (Lovejoy 2014), all of which have been found to possess at least one of these molecules. Using published values of observed production rates of water, GLA, and EG (e.g., Biver et al. 2015), we have estimated a range of masses of these molecules of interest on their host comets. Even with a high degree of uncertainty in comet diameters and volumes, we estimate that 109 to 1017 kg of these molecules could be delivered by a single comet, and that 108 to 1017 kg could have survived the impact.

  2. Potentiation of aquatic pollution by ethylene glycol with regard to the aquatic angiosperm, Lemna gibba

    SciTech Connect

    Thomas, D.A.; Barber, J.T.; Yatsu, L.Y.; Ensley, H.E.

    1995-12-31

    Ethylene glycol is usually thought of as a benign component of urban runoff. Thus, its EC50 value, with regard to the vegetative growth of axenically grown Lemna gibba, is relatively high, viz. 164 mM. Ethylene glycol is not metabolized by Lemna but growth is demonstrably stimulated at concentrations below 75 mM. In the presence of ethylene glycol, the fronds of duckweed are dark green, translucent and the growth medium contains gas bubbles of carbon dioxide which result from an enhanced uptake of sucrose from the growth medium and its subsequent respiration. The uptake is a non-specific effect since the uptake of various other compounds, including water, is enhanced when duckweed is grown in the presence of ethylene glycol. The increased uptake of water, sucrose, inorganic ions and organic compounds results from an increased permeability due to the creation of intercellular holes in the aerenchymatous tissues of the ethylene glycol-treated plants. The mechanism by which ethylene glycol causes the holes is unknown but may involve a disruption in lipid metabolism since the hydrophobicity of the fronds is altered and their lipid composition is changed. The significance of this phenomenon is that toxicants, just like innocuous substances, are taken up in increased amounts by treated plants and as a result their toxicities are increased with regard to duckweed as evidenced by a decrease in their effective concentrations, often of more than 3-fold. These results suggest that although ethylene glycol itself may be benign, its presence in polluted waters containing other toxicants may potentiate the effects of those pollutants.

  3. Comparison of Ethylene Glycol and Propylene Glycol for the Vitrification of Immature Porcine Oocytes

    PubMed Central

    SOMFAI, Tamás; NAKAI, Michiko; TANIHARA, Fuminori; NOGUCHI, Junko; KANEKO, Hiroyuki; KASHIWAZAKI, Naomi; EGERSZEGI, István; NAGAI, Takashi; KIKUCHI, Kazuhiro

    2013-01-01

    Abstract Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35% ethylene glycol (EG), 35% propylene glycol (PG) or a combination of 17.5% EG and 17.5% PG. After warming, the COCs were in vitro matured (IVM), and surviving oocytes were in vitro fertilized (IVF) and cultured. The mean survival rate of vitrified oocytes in 35% PG (73.9%) was higher (P<0.05) than that in 35% EG (27.8%). Oocyte maturation rates did not differ among vitrified and non-vitrified control groups. Blastocyst formation in the vitrified EG group (10.8%) was higher (P<0.05) than that in the vitrified PG group (2.0%) but was lower than that in the control group (25.0%). Treatment of oocytes with 35% of each cryoprotectant without vitrification revealed a higher toxicity of PG on subsequent blastocyst development compared with EG. The combination of EG and PG resulted in 42.6% survival after vitrification. The maturation and fertilization rates of the surviving oocytes were similar in the vitrified, control and toxicity control (TC; treated with EG+PG combination without cooling) groups. Blastocyst development in the vitrified group was lower (P<0.05) than that in the control and TC groups, which in turn had similar development rates (10.7%, 18.1% and 23.3%, respectively). In conclusion, 35% PG enabled a higher oocyte survival rate after vitrification compared with 35% EG. However, PG was greatly toxic to oocytes. The combination of 17.5% EG and 17.5% PG yielded reasonable survival rates without toxic effects on embryo development. PMID:23666455

  4. Comparison of ethylene glycol and propylene glycol for the vitrification of immature porcine oocytes.

    PubMed

    Somfai, Tamás; Nakai, Michiko; Tanihara, Fuminori; Noguchi, Junko; Kaneko, Hiroyuki; Kashiwazaki, Naomi; Egerszegi, István; Nagai, Takashi; Kikuchi, Kazuhiro

    2013-01-01

    Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35% ethylene glycol (EG), 35% propylene glycol (PG) or a combination of 17.5% EG and 17.5% PG. After warming, the COCs were in vitro matured (IVM), and surviving oocytes were in vitro fertilized (IVF) and cultured. The mean survival rate of vitrified oocytes in 35% PG (73.9%) was higher (P<0.05) than that in 35% EG (27.8%). Oocyte maturation rates did not differ among vitrified and non-vitrified control groups. Blastocyst formation in the vitrified EG group (10.8%) was higher (P<0.05) than that in the vitrified PG group (2.0%) but was lower than that in the control group (25.0%). Treatment of oocytes with 35% of each cryoprotectant without vitrification revealed a higher toxicity of PG on subsequent blastocyst development compared with EG. The combination of EG and PG resulted in 42.6% survival after vitrification. The maturation and fertilization rates of the surviving oocytes were similar in the vitrified, control and toxicity control (TC; treated with EG+PG combination without cooling) groups. Blastocyst development in the vitrified group was lower (P<0.05) than that in the control and TC groups, which in turn had similar development rates (10.7%, 18.1% and 23.3%, respectively). In conclusion, 35% PG enabled a higher oocyte survival rate after vitrification compared with 35% EG. However, PG was greatly toxic to oocytes. The combination of 17.5% EG and 17.5% PG yielded reasonable survival rates without toxic effects on embryo development.

  5. Prediction and validation of the duration of hemodialysis sessions for the treatment of acute ethylene glycol poisoning.

    PubMed

    Iliuta, Ioan-Andrei; Lachance, Philippe; Ghannoum, Marc; Bégin, Yannick; Mac-Way, Fabrice; Desmeules, Simon; De Serres, Sacha A; Julien, Anne-Sophie; Douville, Pierre; Agharazii, Mohsen

    2017-08-01

    The duration of hemodialysis (HD) sessions for the treatment of acute ethylene glycol poisoning is dependent on concentration, the operational parameters used during HD, and the presence and severity of metabolic acidosis. Ethylene glycol assays are not readily available, potentially leading to undue extension or premature termination of HD. We report a prediction model for the duration of high-efficiency HD sessions based retrospectively on a cohort study of 26 cases of acute ethylene glycol poisoning in 24 individuals treated by alcohol dehydrogenase competitive inhibitors, cofactors and HD. Two patients required HD for more than 14 days, and two died. In 19 cases, the mean ethylene glycol elimination half-life during high-efficiency HD was 165 minutes (95% confidence interval of 151-180 minutes). In a training set of 12 patients with acute ethylene glycol poisoning, using the 90th percentile half-life (195 minutes) and a target ethylene glycol concentration of 2 mmol/l (12.4 mg/dl) allowed all cases to reach a safe ethylene glycol under 3 mmol/l (18.6 mg/dl). The prediction model was then validated in a set of seven acute ethylene glycol poisonings. Thus, the HD session time in hours can be estimated using 4.7 x (Ln [the initial ethylene glycol concentration (mmol/l)/2]), provided that metabolic acidosis is corrected. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  6. Transport properties of carbon dioxide and ammonia in water - ethylene glycol mixtures from molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Iskrenova, Eugeniya; Patnaik, Soumya S.

    2015-03-01

    The endothermic decomposition of ammonium carbamate has been proposed as a novel heat sink mechanism for aircraft thermal management (Johnson et al. SAE Technical Paper 2012-01-2190, 2012, doi:10.4271/2012-01-2190]). The products of this decomposition are carbon dioxide and ammonia which need to be efficiently removed in order to better control the decomposition reaction. Molecular dynamics simulations can provide insight into the transport properties of carbon dioxide and ammonia in the carrier fluid. In this work, an extensive set of molecular dynamics simulations was performed to better quantify the concentration dependence of solubility and diffusivity of carbon dioxide and ammonia in water, ethylene glycol, and their mixtures at standard temperature and pressure and at elevated temperature. The simulation results confirm the experimental observations that ammonia is more soluble than carbon dioxide in either water or ethylene glycol and that both carbon dioxide and ammonia are more soluble in ethylene glycol than in water. The simulations of water - ethylene glycol mixtures show that increasing the molar fraction of ethylene glycol leads to increased solubility of carbon dioxide and ammonia in the mixture. The authors gratefully acknowledge the DoD High Performance Computing Centers for computational resources.

  7. Effect of poly(ethylene glycol) on phospholipid hydration and polarity of the external phase.

    PubMed

    Arnold, K; Pratsch, L; Gawrisch, K

    1983-02-09

    The hydration properties of phosphatidylcholine (PC)/water dispersions on the addition of poly(ethylene glycol) were studied by means of 2H-NMR. The quadrupole splittings and their temperature dependences correspond to measurements of PC/water dispersions at low water content. It is concluded that the bound water is partly extracted by poly(ethylene glycol) but the binding properties of the water in the inner hydration shell of about five water molecules are not changed. The ability of some phospholipid/water dispersions to undergo phase transitions to nonlamellar structures upon dehydration is discussed. Dipalmitoylphosphatidylcholine (DPPC) and egg phosphatidylcholine do not form nonlamellar structures on addition of purified poly(ethylene glycol), as was demonstrated by means of 31P-NMR. Poly(ethylene glycol) decreases the polarity of the aqueous phase and the partition of hydrophobic molecules between the membrane and the external phase is changed. This was demonstrated using the excimer fluorescence of pyrene in a ghost suspension. It is suggested that the changes in polarity and hydration on the addition of poly(ethylene glycol) can contribute to the alterations in the membrane surface observed under conditions of membrane contact and fusion.

  8. Effect of Hygrophila spinosa in ethylene glycol induced nephrolithiasis in rats.

    PubMed

    Ingale, Kundan G; Thakurdesai, Prasad A; Vyawahare, Neeraj S

    2012-01-01

    Hygrophila spinosa (Acanthaceae) is traditionally used to treat urinary calculi. The present study aimed to evaluate the antiurolithiatic activity of methanolic extract of Hygrophila spinosa (Acanthaceae) in ethylene glycol induced nephrolithiasic rats. Methanolic extract of Hygrophila spinosa (HSME) (250 and 500 mg/ kg body weight) was administered orally to male Wistar albino rats. Ethylene glycol (EG) was used to induce nephrolithiasis. The parameters studied included water intake, urinary volume, urinary pH, urinary and kidney oxalate and calcium, urinary magnesium and serum uric acid. Ethylene glycol feeding resulted in hyperoxaluria as well as increased renal excretion of calcium and serum uric acid along with decreased excretion of urinary magnesium. Treatment with HSME significantly reduced the elevated urinary oxalate, urinary calcium and serum uric acid with increase in reduced urinary magnesium. Ethylene glycol feeding also resulted in increased levels of calcium and oxalate in kidney which was decreased after the treatment with HSME. The increased deposition of stone forming constituents in the kidneys of ethylene glycol treated rats was significantly lowered by treatment with HSME. The results indicate that the aerial parts of Hygrophila spinosa are endowed with antiurolithiatic activity, thereby justifying its traditional claim.

  9. Effect of Hygrophila spinosa in ethylene glycol induced nephrolithiasis in rats

    PubMed Central

    Ingale, Kundan G.; Thakurdesai, Prasad A.; Vyawahare, Neeraj S.

    2012-01-01

    Objective: Hygrophila spinosa (Acanthaceae) is traditionally used to treat urinary calculi. The present study aimed to evaluate the antiurolithiatic activity of methanolic extract of Hygrophila spinosa (Acanthaceae) in ethylene glycol induced nephrolithiasic rats. Materials and Methods: Methanolic extract of Hygrophila spinosa (HSME) (250 and 500 mg/ kg body weight) was administered orally to male Wistar albino rats. Ethylene glycol (EG) was used to induce nephrolithiasis. The parameters studied included water intake, urinary volume, urinary pH, urinary and kidney oxalate and calcium, urinary magnesium and serum uric acid. Results: Ethylene glycol feeding resulted in hyperoxaluria as well as increased renal excretion of calcium and serum uric acid along with decreased excretion of urinary magnesium. Treatment with HSME significantly reduced the elevated urinary oxalate, urinary calcium and serum uric acid with increase in reduced urinary magnesium. Ethylene glycol feeding also resulted in increased levels of calcium and oxalate in kidney which was decreased after the treatment with HSME. The increased deposition of stone forming constituents in the kidneys of ethylene glycol treated rats was significantly lowered by treatment with HSME. Conclusion: The results indicate that the aerial parts of Hygrophila spinosa are endowed with antiurolithiatic activity, thereby justifying its traditional claim. PMID:23112429

  10. Method to Detect Ethylene Glycol in Gaseous Mixtures

    DTIC Science & Technology

    1985-08-01

    is impossible to calculate the strength of the absorption for a transition. The structure of ehtylene glycol has been clarified by studies of...The severity of this problem for ehtylene glycol can only be determined by testing. Clearly, it is very important to minimize 27 AEDC-TR-85-39...the s o u r c e . 28 AEDC-TR-85-39, The most sensitive microwave analyzer for ehtylene glycol would utilize the strongest absorption line whose

  11. 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

  12. Carbohydrate radicals: from ethylene glycol to DNA strand breakage.

    PubMed

    von Sonntag, Clemens

    2014-06-01

    Radiation-induced DNA strand breakage results from the reactions of radicals formed at the sugar moiety of DNA. In order to elucidate the mechanism of this reaction investigations were first performed on low molecular weight model systems. Results from studies on deoxygenated aqueous solutions of ethylene glycol, 2-deoxy-d-ribose and other carbohydrates and, more relevantly, of d-ribose-5-phosphate have shown that substituents can be eliminated from the β-position of the radical site either proton and base-assisted (as in the case of the OH substituent), or spontaneously (as in the case of the phosphate substituent). In DNA the C(4') radical undergoes strand breakage via this type of reaction. In the presence of oxygen the carbon-centred radicals are rapidly converted into the corresponding peroxyl radicals. Again, low molecular weights models have been investigated to elucidate the key reactions. A typical reaction of DNA peroxyl radicals is the fragmentation of the C(4')-C(S') bond, a reaction not observed in the absence of oxygen. Although OH radicals may be the important direct precursors of the sugar radicals of DNA, results obtained with poly(U) indicate that base radicals may well be of even greater importance. The base radicals, formed by addition of the water radicals (H and OH) to the bases would in their turn attack the sugar moiety to produce sugar radicals which then give rise to strand breakage and base release. For a better understanding of strand break formation it is therefore necessary to investigate in more detail the reactions of the base radicals. For a start, the radiolysis of uracil in oxygenated solutions has been reinvestigated, and it has been shown that the major peroxyl radical in this system undergoes base-catalysed elimination of [Formula: see text], a reaction that involves the proton at N(l). In the nucleic acids the pyrimidines are bound at N(l) to the sugar moiety and this type of reaction can no longer occur. Therefore, with

  13. A Structural Transition in Duplex DNA Induced by Ethylene Glycol

    PubMed Central

    Brewood, Greg P.; Aliwarga, Theresa; Schurr, J. Michael

    2010-01-01

    The twist energy parameter (ET) that governs the supercoiling free energy, and the linking difference (Δl) are measured for p30 δ DNA in solutions containing 0 to 40 w/v% ethylene glycol (EG). A plot of ET vs. −ln aw, where aw is the water activity, displays the full (reverse) sigmoidal profile of a discrete structural transition. A general theory for the effect of added osmolyte on a cooperative structural transition between two duplex states, 1□ 2, is formulated in terms of parameters applicable to individual base-pairs subunits. The resulting fraction of base-pairs in the 2-state ( f20), is incorporated into expressions for the effective torsion and bending elastic constants, the effective twist energy parameter ( ETeff), and the change in intrinsic twist (δl0). Fitting the expression for ETeff to the measured ET -values yields reasonably unambiguous estimates of ET1and ET2, the midpoint value (ln aw)1/2, and midpoint slope (∂ET/∂ln aw)1/2, but does not yield unambiguous estimates of the equilibrium constant ( K0), the difference in DNA-water preferential interaction coefficient (ΔΓ), or the inverse cooperativity parameter, J. Fitting a non-cooperative model (assumed J=1.0) to the data yields, K0 = 0.067, and ΔΓ = − 30.0 per base-pair (bp). Essentially equivalent fits are provided by models with a wide range of correlated J, ΔΓ, and K0 values. Other results favor ΔΓ in the range − 1.0 to 0, which then requires K0 ≥ 0.914, and a cooperativity parameter, 1/J ≥ 30.0 bp. The measured δl0 and circular dichroism (CD) at 272 nm are found to be compatible with curves predicted using the same f20-values that best-fit the ET -data. At least 7 to 10 % of the base-pairs are inferred to exist in the 2-state in 0.1 M NaCl in the complete absence of added osmolyte. Compared with the 1-state, the 2-state has a ~2.0- to 2.1-fold greater torsion elastic constant, a ~0.70-fold smaller bending elastic constant, a ~0.91-fold smaller ET -value, a ~0

  14. Electrospraying and Electrospinning of Polymers for Biomedical Applications. Poly(Lactic-Co-Glycolic Acid) and Poly(Ethylene-Co-Vinylacetate). Appendix 2

    NASA Technical Reports Server (NTRS)

    Stitzel, Joel D.; Bowlin, Gary L.; Mansfield, Kevin; Wnek, Gary E.; Simpson, David G.

    2000-01-01

    Significant opportunities exist for the processing of polymers (homopolymers and blends) using electric fields. Specific attention is given here to electrospinning, but we note that electroaerosol formation and field-modulated film casting represent additional processing options. Of particular interest is the ability to generate polymer fibers of sub-micron dimensions using electrospinning, down to about 0.05 microns (50 nm), a size range that has been traditionally difficult to access. In our work, poly(lactic-co-glycolic acid), PLA/PGA, poly(lactic acid) PLA, and poly(ethylene-co-vinylacetate) (PEVA) have been deposited from solutions in methylene chloride or chloroform by electrospraying or electrospinning to afford morphologically tailored materials for tissue engineering and related applications. Low solution concentrations tend to favor electrostatic spraying ('electro-aerosolization') while higher concentrations lead to spinning on fibrous mats. Preliminary observations of muscle cell growth on PLA electrospun mats are reported.

  15. Enhancement of convective heat transfer coefficient of ethylene glycol base cuprous oxide (Cu2O) nanofluids

    NASA Astrophysics Data System (ADS)

    Hassan, Ali; Ramzan, Naveed; Umer, Asim; Ahmad, Ayyaz; Muryam, Hina

    2017-08-01

    The enhancement in the convective heat transfer coefficient of the ethylene glycol (EG) base cuprous oxide (Cu2O) nanofluids were investigated. The nanofluids of different volume concentrations i-e 1%, 2.5% and 4.5% were prepared by the two step method. Cuprous oxide (Cu2O) nanoparticles were ultrasonically stirred for four hours in the ethylene glycol (EG). The experimental study has been performed through circular tube geometry in laminar flow regime at average Reynolds numbers 36, 71 and 116. The constant heat flux Q = 4000 (W/m2) was maintained during this work. Substantial enhancement was observed in the convective heat transfer coefficient of ethylene glycol (EG) base cuprous oxide (Cu2O) nanofluids than the base fluid. The maximum 74% enhancement was observed in convective heat transfer coefficient at 4.5 vol% concentration and Re = 116.

  16. Reduction of friction stress of ethylene glycol by attached hydrogen ions.

    PubMed

    Li, Jinjin; Zhang, Chenhui; Deng, Mingming; Luo, Jianbin

    2014-11-27

    In the present work, it is shown that the friction stress of ethylene glycol can decrease by an order of magnitude to achieve superlubricity if there are hydrogen ions attached on the friction surfaces. An ultra-low friction coefficient (μ = 0.004) of ethylene glycol between Si3N4 and SiO2 can be obtained with the effect of hydrogen ions. Experimental result indicates that the hydrogen ions adsorbed on the friction surfaces forming a hydration layer and the ethylene glycol in the contact region forming an elastohydrodynamic film are the two indispensable factors for the reduction of friction stress. The mechanism of superlubricity is attributed to the extremely low shear strength of formation of elastohydrodynamic film on the hydration layer. This finding may introduce a new approach to reduce friction coefficient of liquid by attaching hydrogen ions on friction surfaces.

  17. Reduction of friction stress of ethylene glycol by attached hydrogen ions

    PubMed Central

    Li, Jinjin; Zhang, Chenhui; Deng, Mingming; Luo, Jianbin

    2014-01-01

    In the present work, it is shown that the friction stress of ethylene glycol can decrease by an order of magnitude to achieve superlubricity if there are hydrogen ions attached on the friction surfaces. An ultra-low friction coefficient (μ = 0.004) of ethylene glycol between Si3N4 and SiO2 can be obtained with the effect of hydrogen ions. Experimental result indicates that the hydrogen ions adsorbed on the friction surfaces forming a hydration layer and the ethylene glycol in the contact region forming an elastohydrodynamic film are the two indispensable factors for the reduction of friction stress. The mechanism of superlubricity is attributed to the extremely low shear strength of formation of elastohydrodynamic film on the hydration layer. This finding may introduce a new approach to reduce friction coefficient of liquid by attaching hydrogen ions on friction surfaces. PMID:25428584

  18. Reduction of friction stress of ethylene glycol by attached hydrogen ions

    NASA Astrophysics Data System (ADS)

    Li, Jinjin; Zhang, Chenhui; Deng, Mingming; Luo, Jianbin

    2014-11-01

    In the present work, it is shown that the friction stress of ethylene glycol can decrease by an order of magnitude to achieve superlubricity if there are hydrogen ions attached on the friction surfaces. An ultra-low friction coefficient (μ = 0.004) of ethylene glycol between Si3N4 and SiO2 can be obtained with the effect of hydrogen ions. Experimental result indicates that the hydrogen ions adsorbed on the friction surfaces forming a hydration layer and the ethylene glycol in the contact region forming an elastohydrodynamic film are the two indispensable factors for the reduction of friction stress. The mechanism of superlubricity is attributed to the extremely low shear strength of formation of elastohydrodynamic film on the hydration layer. This finding may introduce a new approach to reduce friction coefficient of liquid by attaching hydrogen ions on friction surfaces.

  19. Fomepizole for the treatment of pediatric ethylene and diethylene glycol, butoxyethanol, and methanol poisonings.

    PubMed

    Brent, Jeffrey

    2010-06-01

    The use and clinical efficacy of the alcohol dehydrogenase inhibitor fomepizole is well established for the treatment of ethylene glycol and methanol poisonings in adults. A computerized search of the U.S. National Academy of medicine and EMBase databases was undertaken to identify published cases of patients treated with fomepizole. This search strategy identified 14 published cases related to the topic of this review: 10 due to ethylene glycol poisoning, 1 due to diethylene glycol poisoning, 1 due to butoxyethanol ingestion, and 2 due to methanol poisoning. The median age of these cases was 5.5 years old. FOMEPIZOLE IN GLYCOL AND GLYCOL ETHER POISONING: For the 10 ethylene glycol poisoned patients, the median recorded values of their arterial pH was 7.27 (range 7.03-7.38), serum bicarbonate concentration was 13 mEq/L (range 2-25), and ethylene glycol concentration was 2,140 mg/L (range 130-3,840). Eight of these patients were not hemodialyzed. The eight patients who were not hemodialyzed had ethylene glycol concentrations as high as 3,500 mg/L and serum bicarbonate concentrations as low as 4 mEq/L. All 10 patients had resolution of their metabolic acidosis and recovered without sequelae. The half-times of ethylene glycol elimination ranged from 9 to 15 h during fomepizole therapy, which is faster than the 19.7 h reported in adults. The two patients who ingested diethylene glycol or butoxyethanol all recovered without sequelae. The patient who ingested the butoxyethanol had a serum bicarbonate concentration of 13 mEq/L and was not hemodialyzed. FOMEPIZOLE IN METHANOL POISONING: One of the two children who ingested methanol was hemodialyzed. Both cases had a similar degree of severity. DOES FOMEPIZOLE OBVIATE THE NEED FOR HEMODIALYSIS?: Based on the experience reviewed herein it appears that, as in adults, hemodialysis may not be necessary in most cases of pediatric ethylene glycol poisoning if treated with fomepizole. FOMEPIZOLE PHARMACOKINETICS: Plasma fomepizole

  20. Anti-inflammatory effects of royal jelly on ethylene glycol induced renal inflammation in rats.

    PubMed

    Aslan, Zeyneb; Aksoy, Laçine

    2015-01-01

    In this study, anti-inflammatory effects of Royal Jelly were investigated by inducing renal inflammation in rats with the use of ethylene glycol. For this purpose, the calcium oxalate urolithiasis model was obtained by feeding rats with ethylene glycol in drinking water. The rats were divided in five study groups. The 1st group was determined as the control group. The rats in the 2nd group received ethylene glycol (1%) in drinking water. The rats in the 3rd group were daily fed with Royal Jelly by using oral gavage. The 4th group was determined as the preventive group and the rats were fed with ethylene glycol (1%) in drinking water while receiving Royal Jelly via oral gavage. The 5th group was determined as the therapeutic group and received ethylene glycol in drinking water during the first 2 weeks of the study and Royal Jelly via oral gavage during the last 2 weeks of the study. At the end of the study, proinflammatory/anti-inflammatory cytokines, TNF-a, IL-1ß and IL-18 levels in blood and renal tissue samples from the rats used in the application were measured. The results have shown that ethylene glycol does induce inflammation and renal damage. This can cause the formation of reactive oxygen species. Royal Jelly is also considered to have anti-inflammatory effects due to its possible antiradical and antioxidative effects. It can have positive effects on both the prevention of urolithiasis and possible inflammation during the existing urolithiasis and support the medical treatment.

  1. Inhibited ethylene and propylene glycols for corrosion and freeze protection in water-based HVAC systems

    SciTech Connect

    Roo, A.M. de; Lee, B.W.

    1997-12-31

    Industrially inhibited ethylene and propylene glycols are used extensively to provide protection against equipment damage due to corrosion and freezing. This paper will describe the proper use of these glycols, including system preparation, fluid installation, and fluid maintenance. The impact of the use of these glycols on the operation of the system is discussed along with methods for overcoming any declines in heat transfer. From this discussion, it will become clear why automotive antifreeze formulations should not be used in heating, ventilating, and airconditioning (HVAC) systems. Also included are data on the physical properties of aqueous solutions of ethylene and propylene glycol, the concept of burst vs. freeze protection, typical results of corrosion tests, and methods to use to monitor the fluid for each application.

  2. Solvothermal synthesis of fusiform hexagonal prism SrCO{sub 3} microrods via ethylene glycol solution

    SciTech Connect

    Shi Liange; Du Fanglin . E-mail: dufanglin@qust.edu.cn

    2007-08-07

    Fusiform hexagonal prism SrCO{sub 3} microrods were prepared by a simple solvothermal route at 120 deg. C, and characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FT-IR) spectroscopy. By controlling the content of ethylene glycol (EG), it was found that ethylene glycol (EG) played an important role in the formation of such SrCO{sub 3} microrods. Finally, effects of other solvents on the products, including 1,2-propanediol and glycerin, were also investigated.

  3. [Determination of ethylene glycol in workplace air by capillary column gas chromatography].

    PubMed

    Li, Tiandi; Lin, Yiran; Zhang, Wen; He, Juntao

    2015-12-01

    To establish the method of capillary column gas chromatography for determination of ethylene glycol in workplace air. Ethylene glycol in workplace air was collected with silicone tube, desorbed with methanol, separated with FFAP (nitroterephthalic acid-modified polyethylene glycol)capillary column, and measured with flame ionization detector. The detection limit of ethylene glycol was 0.41 mg/L, the lower limit of quantification was 1.4 mg/L, the range of measurement was 1.4~163.9 mg/L, and the minimum detectable concentration was 0.3 mg/m3 (1.5 L of air was collected as the sample). This method had a good repeatability, the relative standard deviation was 1.4%~5.2%, the average desorption efficiency was 94.4%~101.7%, and the sampling efficiency was 99.2%~100%. The penetrating capacity of 200 mg silicone was higher than 6.9 mg, and the samples could be preserved for 14 days at room temperature. The method has a low detection limit, high accuracy, and good precision, which is feasible for determination of ethylene glycol in workplace air.

  4. Ethylene Glycol Adsorption and Reaction over CeOX(111) Thin Films

    SciTech Connect

    T Chen; D Mullins

    2011-12-31

    This study reports the interaction of ethylene glycol with well-ordered CeO{sub x}(111) thin film surfaces. Ethylene glycol initially adsorbs on fully oxidized CeO{sub 2}(111) and reduced CeO{sub 2-x}(111) through the formation of one C-O-Ce bond and then forms a second alkoxy bond after annealing. On fully oxidized CeO{sub 2}(111) both recombination of ethylene glycol and water desorption occur at low temperature leaving stable -OCH{sub 2}CH{sub 2}O- (ethylenedioxy) intermediates and oxygen vacancies on the surface. This ethylenedioxy intermediate goes through C-C bond scission to produce formate species which then react to produce CO and CO{sub 2}. The formation of water results in the reduction of the ceria. On a reduced CeO{sub 2-x}(111) surface the reaction selectivity shifts toward a dehydration process. The ethylenedioxy intermediate decomposes by breaking a C-O bond and converts into an enolate species. Similar to the reaction of acetaldehyde on reduced CeO{sub 2-x}(111), the enolate reacts to produce acetaldehyde, acetylene, and ethylene. The loss of O from ethylene glycol leads to a small amount of oxidation of the reduced ceria.

  5. Ethylene Glycol Adsorption and Reaction over CeOX(111) Thin Films

    SciTech Connect

    Mullins, David R; Chen, Tsung-Liang

    2011-01-01

    This study reports the interaction of ethylene glycol with well-ordered CeO{sub x}(111) thin film surfaces. Ethylene glycol initially adsorbs on fully oxidized CeO{sub 2}(111) and reduced CeO{sub 2-x}(111) through the formation of one C-O-Ce bond and then forms a second alkoxy bond after annealing. On fully oxidized CeO{sub 2}(111) both recombination of ethylene glycol and water desorption occur at low temperature leaving stable -OCH{sub 2}CH{sub 2}O- (ethylenedioxy) intermediates and oxygen vacancies on the surface. This ethylenedioxy intermediate goes through C-C bond scission to produce formate species which then react to produce CO and CO{sub 2}. The formation of water results in the reduction of the ceria. On a reduced CeO{sub 2-x}(111) surface the reaction selectivity shifts toward a dehydration process. The ethylenedioxy intermediate decomposes by breaking a C-O bond and converts into an enolate species. Similar to the reaction of acetaldehyde on reduced CeO{sub 2-x}(111), the enolate reacts to produce acetaldehyde, acetylene, and ethylene. The loss of O from ethylene glycol leads to a small amount of oxidation of the reduced ceria.

  6. 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.

  7. 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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Hemodiafiltration efficacy in treatment of methanol and ethylene glycol poisoning in a 2-year-old girl.

    PubMed

    Szmigielska, Agnieszka; Szymanik-Grzelak, Hanna; Kuźma-Mroczkowska, Elżbieta; Roszkowska-Blaim, Maria

    2015-01-01

    Every year about 2.4 million people in USA are exposed to toxic substances. Many of them are children below 6 years of age. Majority of poisonings in children are incidental and related to household products including for example drugs, cleaning products or antifreeze products. Antifreeze solutions contain ethylene glycol and methanol. Treatment of these toxic substances involves ethanol administration, fomepizole, hemodialysis and correction of metabolic acidosis. The aim of the study was to check the efficacy of continuous venovenous hemodiagiltration in intoxication with ethylene glycol and methanol. One year and 7 months old girl after intoxication with ethylene glycol and methanol was treated with continuous venovenous hemodiafiltration instead of hemodialysis because of technical problems (circulatory instability). Intravenous ethanol infusion with hemodialtration resulted in rapid elimination of methanol from the body and significantly reduced blood ethylene glycol level. Continuous venovenous hemodiafiltration can be helpful in treatment of ethylene glycol and methanol intoxication.

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

    PubMed

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

    2016-03-01

    The development of lignocellulose as a sustainable resource for the production of fuels and chemicals will rely on technology capable of converting the raw materials into useful compounds; some such transformations can be achieved by biological processes employing engineered microorganisms. Towards the goal of valorizing the hemicellulose fraction of lignocellulose, we designed and validated a set of pathways that enable efficient utilization of pentoses for the biosynthesis of notable two-carbon products. These pathways were incorporated into Escherichia coli, and engineered strains produced ethylene glycol from various pentoses, including simultaneously from D-xylose and L-arabinose; one strain achieved the greatest reported titer of ethylene glycol, 40 g/L, from D-xylose at a yield of 0.35 g/g. The strategy was then extended to another compound, glycolate. Using D-xylose as the substrate, an engineered strain produced 40 g/L glycolate at a yield of 0.63 g/g, which is the greatest reported yield to date. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  10. The significance of water quality guidelines in environmental decision making: Ethylene glycol -- A case example

    SciTech Connect

    Craig, G.R.; Gilron, G.L.; Bishop, J.; Cerf, J.; Williams, J.

    1995-12-31

    Ethylene glycol is a principal component of deicing and anti-icing products commonly applied to aircraft in winter prior to take-off. Many airports do not have efficient collection systems in place surrounding aquatic environments and biota are often exposed to ethylene glycol contained in direct runoff and snowmelt. This study was designed to fulfill the minimum ecotoxicity data requirements for the development of a water quality guideline for ethylene glycol. Ecotoxicity testing was conducted using reagent-grade ethylene glycol and exposure concentrations were confirmed by GC/FID direct aqueous injection, or based on spectrophotometric measurement of the purpene-glycol reaction. The highest ethylene glycol NOEC values for the organisms tested included rainbow trout fry growth 14,692 mg/L, fathead minnow fry growth 12,531 mg/l, Ceriodaphnia dubia reproduction 3,469 mg/L, the ciliate Colpidium campylum 28,090 mg/L, and the rotifer Brachionus calyciflorus 12,800 mg/L. The highest non-lethal level for rainbow trout and the for the frog Xenopus laevis was 12,500 mg/L. Results indicated that the 48-hr LC50 for Xenopus laevis reported in an earlier study (and which was used in the derivation of some interim guidelines) could not be reproduced. However, results of the fish and invertebrate tests compared favorably with other literature values for similar species and with QSAR estimates. A number of water quality derivation protocols (CCME, Ontario MOE, and US EPA) were applied to the data set for the comparison of generated guideline values. Differences in values demonstrate the economic need for using a common approach in developing guidelines that are used to assess hazard to similar ecosystems in different jurisdictions within a global marketplace.

  11. Synthesis and antimalarial activity of ethylene glycol oligomeric ethers of artemisinin.

    PubMed

    Steyn, Minette; N'Da, David D; Breytenbach, Jaco C; Smith, Peter J; Meredith, Sandra; Breytenbach, Wilma J

    2011-02-01

    The aim of this study was to synthesize a series of ethylene glycol ether derivatives of the antimalarial drug artemisinin, determine their values for selected physicochemical properties and evaluate their antimalarial activity in vitro against Plasmodium falciparum strains.   The ethers were synthesized in a one-step process by coupling ethylene glycol moieties of various chain lengths to carbon C-10 of artemisinin. The aqueous solubility and log D values were determined in phosphate buffered saline (pH 7.4). The derivatives were screened for antimalarial activity alongside artemether and chloroquine against chloroquine-sensitive (D10) and moderately chloroquine-resistant (Dd2) strains of P. falciparum. The aqueous solubility within each series increased as the ethylene glycol chain lengthened. The IC50 values revealed that all the derivatives were active against both D10 and Dd2 strains. All were less potent than artemether irrespective of the strain. However, they proved to be more potent than chloroquine against the resistant strain. Compound 8, featuring three ethylene oxide units, was the most active of all the synthesized ethers. The conjugation of dihydroartemisinin to ethylene glycol units of various chain lengths through etheral linkage led to water-soluble derivatives. The strategy did not result in an increase of antimalarial activity compared with artemether. It is nevertheless a promising approach to further investigate and synthesize water-soluble derivatives of artemisinin that may be more active than artemether by increasing the ethylene glycol chain length. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society.

  12. Human Oocyte Vitrification: The permeability of metaphase II oocytes to water and ethylene glycol and the appliance toward vitrification

    PubMed Central

    Mullen, Steven F.; Li, Mei; Li, Yuan; Chen, Zi-Jiang; Critser, John K.

    2008-01-01

    Objectives To determine the permeability of human metaphase II oocytes to ethylene glycol and water in the presence of ethylene glycol, and to use this information to develop a method to vitrify human oocytes. Design An incomplete randomized block design was used for this study. Setting A University-affiliated assisted reproductive center. Patients Women undergoing assisted reproduction in the Center for Reproductive Medicine at Shandong University. Interventions Oocytes were exposed to 1.0 molar ethylene glycol in a single step, and photographed during subsequent volume excursions. Main outcome measures A 2-parameter model was employed to estimate the permeability to water and EG. Results Water permeability ranged from 0.15 to 1.17 µm/(min·atm), and ethylene glycol permeability ranged from 1.5 to 30 µm/min between 7 °C at 36 °C. The activation energies for water and ethylene glycol permeability were 14.42 Kcal/mol and 21.20 Kcal/mol, respectively. Conclusions Despite the lower permeability of human MII oocytes to ethylene glycol compared to previously published values for propylene glycol and dimethylsulfoxide, methods to add and remove human oocytes with a vitrifiable concentration of ethylene glycol can be designed which prevent excessive osmotic stress and minimize exposure to high concentrations of this compound. PMID:17681308

  13. Ethylene glycol poisoning: a rare but life-threatening cause of metabolic acidosis—a single-centre experience

    PubMed Central

    Kimmel, Martin; Alscher, Mark Dominik; Braun, Niko

    2012-01-01

    Background. Intoxication with ethylene glycol happen all around the world and without rapid recognition and early treatment, mortality from this is high. Methods. In our study, we retrospectively analysed six cases of ethylene glycol intoxication in our department. We measured ethylene glycol or glycolate levels, lactate levels and calculated the osmolal and anion gap. Results. Data from six patients admitted to the nephrology department between 1999 and 2011 with ethylene glycol poisoning are reported. All patients were men. The mean pH on admission was 7.15 ± 0.20 and the anion and osmolal gap were elevated in five of six patients. Four patients had an acute kidney injury and one patient had an acute-on-chronic kidney injury. All patients survived and after being discharged, two patients required chronic intermittent haemodialysis. Interestingly, at the time of admission, all patients had elevated lactate levels but there was no linear regression between toxic levels and lactate levels and no linear correlation was found between initial lactate levels and anion gap and osmolal gap. Conclusions. The initial diagnosis of ethylene glycol poisoning is difficult and poisoning with ethylene glycol is rare but life threatening and needs rapid recognition and early treatment. Therefore, intoxication with ethylene glycol should not be misdiagnosed as lactic acidosis in patients with metabolic acidosis and elevated lactate levels. PMID:25503773

  14. BULK SYNTHESIS OF SILVER NANORODS IN POLY(ETHYLENE GLYCOL) USING MICROWAVE IRRADIATION

    EPA Science Inventory

    Microwave-assisted (MW), surfactantless, greener approach to bulk synthesis of silver nanorods employing poly (ethylene glycol) (PEG) is described. An aqueous solution of silver nitrate (AgNO-3,- 0.1 M, 4 mL) and 4 mL of PEG (molecular weight 300) were mixed at room temperature t...

  15. Detection of ethylene glycol - toward W51/e2 and G34.3+0.02

    NASA Astrophysics Data System (ADS)

    Lykke, Julie M.; Favre, Cécile

    2014-07-01

    Ethylene glycol (HOCH2CH2OH), also commenly known as antifreeze, is the reduced alcohol version of glycolaldehyde (CH2OHCHO). Glycoladehyde - the simplest possible aldehyde sugar (Marstokk and Møllendal 1973) - is the first intermediate step in the path toward forming more complex and biologically relevant molecules through the the formose reaction, which begins with formaldehyde (H2CO) and ends with the formation of sugars and ultimately ribose, the backbone of RNA (e.g., Larralde et al. 1995). The presence of glycolaldehyde is therefore an important indication that processes leading to biologically relevant molecules are taking place. It is however, still unclear as to how glycolaldehyde and ethylene glycol are formed in the ISM. It has been proposed that they share a common formation pathway through UV-irradiation of methanol (CH3OH) ices mixed with CO (Öberg et al. 2009). So far, ethylene glycol, in its lower energy con-former (g’Ga(CH2OH)2), has been detected toward SgrB2 (N) by Hollis et al. (2002), tentatively toward IRAS 16293-2422 (Jørgensen et al. 2012) and marginally by Kalenskii and Johansson (2010) toward W51 e1/e2. Here we present a firm detection of ethylene glycol toward W51/e2 as well as a first detection toward G34.3+0.02 at 1mm and 3mm using the IRAM 30m telescope.

  16. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (Interagency Science Discussion Draft)

    EPA Science Inventory

    EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from ot...

  17. IRIS Toxicological Review of Ethylene Glycol Mono Butyl Ether (Egbe) (Final Report)

    EPA Science Inventory

    EPA has finalized the Toxicological Review of Ethylene Glycol Mono Butyl Ether: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

  18. An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether (Egbe)

    EPA Science Inventory

    This position paper, An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether, was developed in support of the EPA's evaluation of a petition from the American Chemistry Council requesting to delist EGBE per the Clean Air Act Amendments (CAAA), Titl...

  19. IRIS Toxicological Review of Ethylene Glycol Mono-Butyl Ether (Egbe) (Interagency Science Discussion Draft)

    EPA Science Inventory

    EPA released the draft report, Toxicological Review for Ethylene Glycol Mono-Butyl Ether , that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from ot...

  20. IRIS Toxicological Review of Ethylene Glycol Mono Butyl Ether (Egbe) (Final Report)

    EPA Science Inventory

    EPA has finalized the Toxicological Review of Ethylene Glycol Mono Butyl Ether: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

  1. BULK SYNTHESIS OF SILVER NANORODS IN POLY(ETHYLENE GLYCOL) USING MICROWAVE IRRADIATION

    EPA Science Inventory

    Microwave-assisted (MW), surfactantless, greener approach to bulk synthesis of silver nanorods employing poly (ethylene glycol) (PEG) is described. An aqueous solution of silver nitrate (AgNO-3,- 0.1 M, 4 mL) and 4 mL of PEG (molecular weight 300) were mixed at room temperature t...

  2. In situ mixed donor synthesis of ampicillin with ethylene glycol co-solvent.

    PubMed

    Deaguero, Andria L; Bommarius, Andreas S

    2014-05-01

    Ethylene glycol has the ability to act as a reactant when employed as a co-solvent for the enzymatic synthesis of ampicillin from (R)-phenylglycine methyl ester and 6-aminopenicillanic acid. The side reaction positively affects yield because its product, (R)-phenylglycine hydroxyethyl ester, is an intermediate for ampicillin synthesis. © 2013 Wiley Periodicals, Inc.

  3. The Effect of Ethylene Glycol, Glycine Betaine, and Urea on Lysozyme Thermal Stability

    ERIC Educational Resources Information Center

    Schwinefus, Jeffrey J.; Leslie, Elizabeth J.; Nordstrom, Anna R.

    2010-01-01

    The four-week student project described in this article is an extension of protein thermal denaturation experiments to include effects of added cosolutes ethylene glycol, glycine betaine, and urea on the unfolding of lysozyme. The transition temperatures and van't Hoff enthalpies for unfolding are evaluated for six concentrations of each cosolute,…

  4. Preparation of size tunable giant vesicles from cross-linked dextran(ethylene glycol) hydrogels.

    PubMed

    López Mora, Néstor; Hansen, Jesper S; Gao, Yue; Ronald, Andrew A; Kieltyka, Roxanne; Malmstadt, Noah; Kros, Alexander

    2014-02-25

    We present a novel chemically cross-linked dextran-poly(ethylene glycol) hydrogel substrate for the preparation of dense vesicle suspensions under physiological ionic strength conditions. These vesicles can be easily diluted for individual study. Modulating the degree of cross-linking within the hydrogel network results in tuning of the vesicle size distribution.

  5. An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether (Egbe)

    EPA Science Inventory

    This position paper, An Evaluation of the Human Carcinogenic Potential of Ethylene Glycol Butyl Ether, was developed in support of the EPA's evaluation of a petition from the American Chemistry Council requesting to delist EGBE per the Clean Air Act Amendments (CAAA), Titl...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  7. The Effect of Ethylene Glycol, Glycine Betaine, and Urea on Lysozyme Thermal Stability

    ERIC Educational Resources Information Center

    Schwinefus, Jeffrey J.; Leslie, Elizabeth J.; Nordstrom, Anna R.

    2010-01-01

    The four-week student project described in this article is an extension of protein thermal denaturation experiments to include effects of added cosolutes ethylene glycol, glycine betaine, and urea on the unfolding of lysozyme. The transition temperatures and van't Hoff enthalpies for unfolding are evaluated for six concentrations of each cosolute,…

  8. Spectrophotometric technique quantitatively determines NaMBT inhibitor in ethylene glycol-water solutions

    NASA Technical Reports Server (NTRS)

    Garrard, G. G.

    1967-01-01

    Spectrophotometric method, using a ratio-recording ultraviolet-absorption spectrophotometer, permits analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to detect extremely small concentrations of mercaptobenzothiazole.

  9. Insights on cryoprotectant toxicity from gene expression profiling of endothelial cells exposed to ethylene glycol.

    PubMed

    Cordeiro, Rui Martins; Stirling, Soren; Fahy, Gregory M; de Magalhães, João Pedro

    2015-12-01

    Cryopreservation consists of preserving living cells or tissues generally at -80 °C or below and has many current applications in cell and tissue banking, and future potential for organ banking. Cryoprotective agents such as ethylene glycol (EG) are required for successful cryopreservation of most living systems, but have toxic side effects whose mechanisms remain largely unknown. In this work, we investigated the mechanisms of toxicity of ethylene glycol in human umbilical vein endothelial cells (HUVECs) as a model of the vascular endothelium in perfused organs. Exposing cells to 60% v/v EG for 2 h at 4 °C resulted in only a slight decrease in subsequent cell growth, suggesting only modest toxicity of EG for this cell type. Gene expression analysis with whole genome microarrays revealed signatures indicative of a generalized stress response at 24 h after EG exposure and a trend toward partial recovery at 72 h. The observed changes involved signalling pathways, glycoproteins, and genes involved in extracellular and transmembrane functions, the latter suggesting potential effects of ethylene glycol on membranes. These results continue to develop a new paradigm for understanding cryoprotectant toxicity and reveal molecular signatures helpful for future experiments in more completely elucidating the toxic effects of ethylene glycol in vascular endothelial cells and other cell types. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Exposure of German residents to ethylene and propylene glycol ethers in general and after cleaning scenarios.

    PubMed

    Fromme, H; Nitschke, L; Boehmer, S; Kiranoglu, M; Göen, T

    2013-03-01

    Glycol ethers are a class of semi-volatile substances used as solvents in a variety of consumer products like cleaning agents, paints, cosmetics as well as chemical intermediates. We determined 11 metabolites of ethylene and propylene glycol ethers in 44 urine samples of German residents (background level study) and in urine samples of individuals after exposure to glycol ethers during cleaning activities (exposure study). In the study on the background exposure, methoxyacetic acid and phenoxyacetic acid (PhAA) could be detected in each urine sample with median (95th percentile) values of 0.11 mgL(-1) (0.30 mgL(-1)) and 0.80 mgL(-1) (23.6 mgL(-1)), respectively. The other metabolites were found in a limited number of samples or in none. In the exposure study, 5-8 rooms were cleaned with a cleaner containing ethylene glycol monobutyl ether (EGBE), propylene glycol monobutyl ether (PGBE), or ethylene glycol monopropyl ether (EGPE). During cleaning the mean levels in the indoor air were 7.5 mgm(-3) (EGBE), 3.0 mgm(-3) (PGBE), and 3.3 mgm(-3) (EGPE), respectively. The related metabolite levels analysed in the urine of the residents of the rooms at the day of cleaning were 2.4 mgL(-1) for butoxyacetic acid, 0.06 mgL(-1) for 2-butoxypropionic acid, and 2.3 mgL(-1) for n-propoxyacetic acid. Overall, our study indicates that the exposure of the population to glycol ethers is generally low, with the exception of PhAA. Moreover, the results of the cleaning scenarios demonstrate that the use of indoor cleaning agents containing glycol ethers can lead to a detectable internal exposure of residents. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. A positive chemical ionization GC/MS method for the determination of airborne ethylene glycol and propylene glycols in non-occupational environments.

    PubMed

    Zhu, Jiping; Feng, Yong-Lai; Aikawa, Bio

    2004-11-01

    An analytical method for ethylene glycol and propylene glycols has been developed for measuring airborne levels of these chemicals in non-occupational environments such as residences and office buildings. The analytes were collected on charcoal tubes, solvent extracted, and analyzed by gas chromatography-mass spectrometry using a positive chemical ionization technique. The method had a method detection limit of 0.07 microg m(-3) for ethylene glycol and 0.03 microg m(-3) for 1,2- and 1,3-propylene glycols, respectively, based on a 1.44 m3 sampling volume. Indoor air samples of several residential homes and other indoor environments have been analyzed. The median concentrations of ethylene glycol and 1,2-propylene glycol in nine residential indoor air samples were 53 microg m(-3) and 13 microg m(-3) respectively with maximum values of 223 microg m(-3) and 25 microg m(-3) detected for ethylene glycol and 1,2-propylene glycol respectively. The concentrations of these two chemicals in one office and two laboratories were at low microg m(-3) levels. The maximum concentration of 1,3-propylene glycol detected in indoor air was 0.1 microg m(-3).

  12. Thermosensitivity of bile acid-based oligo(ethylene glycol) stars in aqueous solutions.

    PubMed

    Strandman, Satu; Le Dévédec, Frantz; Zhu, X X

    2011-08-03

    Amphiphilic star-shaped oligo(ethylene glycol)s with a hydrophobic bile acid core and varying number of hydrophilic arms have been made. Their thermal behavior in aqueous solutions depends on the number rather than the length of the arms. The two-armed lithocholate derivative showed the strongest tendency for association and exhibited the lowest cloud point (79 °C) of the oligomers made, as well as another phase separation at a lower temperature (31 °C). The "double thermosensitivity" arising both from the salt-dependent LCST of the oligo(ethylene glycol) segments and the temperature-responsive self-assembly of amphiphilic bile acid derivative provides an interesting path in the design of bile acid-based smart materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    SciTech Connect

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

    2005-10-01

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

  14. Comparison of the metabolism of ethylene glycol and glycolic acid in vitro by precision-cut tissue slices from female rat, rabbit and human liver.

    PubMed

    Booth, E D; Dofferhoff, O; Boogaard, P J; Watson, W P

    2004-01-01

    1. The metabolism of [1,2-(14)C]-ethylene glycol and [1,2-(14)C]-glycolic acid was studied in vitro using precision-cut tissue slices prepared from the livers of female Sprague-Dawley rats, New Zealand white rabbits and humans. The time-course for production of metabolites formed from ethylene glycol at concentrations from 3 to 40 mM was determined to compare quantitatively the differences between species in the rates and amounts of formation of glycolic acid, the presumed developmental toxicant of ethylene glycol. The rates of metabolism of glycolic acid to glyoxylic acid at concentrations from 0.05 to 16 mM by liver tissue from the different species were also determined. The apparent V(max)/K(m) for the metabolic conversions of ethylene glycol to glycolic acid and for glycolic acid to glyoxylic acid in liver tissue from the different species were obtained. 2. There were qualitative differences in the metabolic profiles and quantitative differences in the formation of glycolic acid between the mammalian liver systems. There was an average of 10-fold less glycolic acid produced by liver slices from rabbits compared with rats. With the human liver, the formation of glycolic acid was not detectable using tissue from three of four human donors. A low level of glycolic acid was detected in one liver slice incubation from one of the four subjects, but only at one extended time point; glyoxylate was detected with liver slices from all four humans. 3. Liver slices prepared from female Sprague-Dawley rats, female New Zealand White rabbits and three female human subjects all metabolized glycolic acid to glyoxylic acid. Human liver tissue was the most effective at further metabolizing glycolic acid to glyoxylic acid. The ratios of V(max)/K(m), representing the relative clearance of glycolic acid from liver tissue, were approximately 14:9:1 for human, rat and rabbit liver, respectively. 4. Precision-cut liver slices maintained in dynamic organ culture are good predictors of

  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. Copyright © 2015. Published by Elsevier B.V.

  16. Dielectric behavior of lysozyme and ferricytochrome-c in water/ethylene-glycol solutions.

    PubMed

    Bonincontro, A; Cinelli, S; Onori, G; Stravato, A

    2004-02-01

    This work deals with a dielectric study at radio frequencies of the influence at room temperature of two organic molecules, known as cryo-protectants, ethylene-glycol and glycerol, on conformational and dynamic properties of two model proteins, lysozyme (lys) from chicken egg-white and ferricytochrome-c (cyt-c) from horse heart. Cyt-c is a compact globular protein whereas lys is composed of two structural domains, separated by the active site cleft. Measurements were carried out at the fixed temperature of 20 degrees C varying the concentration of the cosolvent up to 90% w/w. From the analysis of the dielectric relaxation of the protein solution, the effective hydrodynamic radius and the electric dipole moment of the protein were calculated as a function of the cosolvent concentration. The data show that glycerol does not modify significantly the conformation of both proteins and cyt-c is also stable in the presence of ethylene-glycol. On the contrary ethylene-glycol strongly affects the dielectric response of lysozyme denoting a specific effect on its conformation and dynamics. The data are coherently interpreted hypothesizing that glycol molecule wedges between and separates the two domains of lys making them rotationally independent.

  17. Validation of a rapid, automated method for the measurement of ethylene glycol in human plasma.

    PubMed

    Robson, Anna F; Lawson, Alexander J; Lewis, Laura; Jones, Alan; George, Stephen

    2017-07-01

    Background Ethylene glycol is a highly toxic compound found in various household products. Cases of poisoning are rare but may be fatal unless diagnosed and treated promptly. Early recognition of poisoning is critical for the management and recovery of patients. Indirect testing is not specific for the presence of ethylene glycol. Therefore, urgent and accurate measurement should be sought if ingestion is suspected in order to determine the need for treatment with an antidote. Here, we present the validation of an automated assay for measurement of ethylene glycol on an Abbott Architect using a commercially available kit (Catachem). Methods Analytical parameters of imprecision, linearity, stability and bias were determined using spiked human plasma samples processed on both the Catachem assay and on an in-house gas chromatography-mass spectrometry method. Interference was assessed using samples collected into a variety of sample collection tubes and spiked with a number of alcohols. Results Excellent agreement was observed between the two methodologies with the enzymatic assay demonstrating linearity and precision across the relevant clinical range (50-3000 mg/L). In addition, the Catachem assay displayed no interference from a number of different sample tubes and alcohols. However, propylene glycol interference was observed at concentrations associated with excessive use (>1 g/L) and 2,3-butanediol interference observed at concentrations associated with butanone ingestion. Inspection of the enzymatic reaction profile was found to differentiate between alcohols. Conclusions This automated assay is suitable for the diagnosis of ethylene glycol poisoning and is now in routine use, enabling the laboratory to provide a rapid 24 h service with support by gas chromatography-mass spectrometry as necessary.

  18. Synthesis and water-swelling of thermo-responsive poly(ester urethane)s containing poly(epsilon-caprolactone), poly(ethylene glycol) and poly(propylene glycol).

    PubMed

    Loh, Xian Jun; Colin Sng, Kian Boon; Li, Jun

    2008-08-01

    Thermo-responsive multiblock poly(ester urethane)s comprising poly(epsilon-caprolactone) (PCL), poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) segments were synthesized. The copolymers were characterized by GPC, NMR, FTIR, XRD, DSC and TGA. Water-swelling analysis carried out at different temperatures revealed that the bulk hydrophilicity of the copolymers could be controlled either by adjusting the composition of the copolymer or by changing the temperature of the environment. These thermo-responsive copolymer films formed highly swollen hydrogel-like materials when soaked in cold water and shrank when soaked in warm water. The changes are reversible. The mechanical properties of the copolymer films were assessed by tensile strength measurement. These copolymers were ductile when compared to PCL homopolymers. Young's modulus and the stress at break increased with increasing PCL content, whereas the strain at break increased with increasing PEG content. The results of the cytotoxicity tests based on the ISO 10993-5 protocol demonstrated that the copolymers were non-cytotoxic and could be potentially used in biomedical applications.

  19. Ethylene glycol (antifreeze) poisoning in a free-ranging polar bear

    SciTech Connect

    Amstrup, S.C.; Gardner, C.; Myers, K.C.; Oehme, F.W. )

    1989-08-01

    The bright, fluorescent pink-colored remains of a polar bear were found on an Alaskan island with the gravel and snow adjacent to the bear colored bright purple. Traces of fox urine and feces found nearby were also pink. The pink and purple colors were due to rhodamine B, and ethylene glycol (EG) was present in the soil under the carcass. Evidence is given to suggest the bear consumed a mixture of rhodamine B and EG commonly used to mark roads and runways during snow and ice periods. Such wildlife losses could be prevented by substituting propylene glycol for the EG in such mixtures.

  20. Effects of ethylene glycol ethers on the reproduction of Ceriodaphnia dubia.

    PubMed

    Devillers, J; Chezeau, A; Poulsen, V; Thybaud, E

    2003-01-01

    Seven-day static renewal tests with Ceriodaphnia dubia were used to document the chronic toxicity of ethylene glycol ethers and acetates to this invertebrate. The 7-d EC10 (effective concentrations inducing an inhibition of 10% of the reproduction of the tested organisms) values ranged from 0.06 to 1025 mg/l. While a survey of the literature showed that the acute toxicity of these chemicals appeared negligible, our results clearly revealed the potential chronic effects of some of them to this organism occupying an important trophic level in the aquatic ecosystems. The usefulness of this kind of test to better estimate the adverse effects of glycol ethers was stressed.

  1. Polar stationary phases based on poly(oligo ethylene glycol)diacrylates for capillary gas chromatography

    NASA Astrophysics Data System (ADS)

    Shiryaeva, V. E.; Popova, T. P.; Korolev, A. A.; Kanat'eva, A. Yu.; Kurganov, A. A.

    2017-08-01

    New stationary phases for capillary columns in GC are synthesized and studied. The phases are prepared by depositing oligo(ethylene glycol)diacrylates on the column walls and subsequent polymerization (crosslinking) in the presence of peroxide initiators. It is shown that stationary phases based on monomers with molecular weights of 10 kDa or higher exhibit separation properties similar to those of conventional stationary phases based on polyethylene glycol (PEG); however, their thermal stability is higher because they have a higher degree of crosslinking and a more ordered structure of the crosslinked polymers than the respective parameters of phases based on native PEG.

  2. Ethylene glycol (antifreeze) poisoning in a free-ranging polar bear

    USGS Publications Warehouse

    Amstrup, Steven C.; Gardner, Craig L.; Myers, Kevin C.; Oehme, Frederick W.

    1989-01-01

    The bright, fluorescent pink-colored remains of a polar bear were found on an Alaskan island with the gravel and snow adjacent to the bear colored bright purple. Traces of fox urine and feces found nearby were also pink. The punk and purple colors were due to rhodamine B, and ethylene glycol (EG) was present in the soil under the carcass. Evidence is given to suggest the bear consumed a mixture of rhodamine B and EG commonly used to mark roads and runways during snow and ice periods. Such wildlife losses could be prevented by substituting propylene glycol for the EG in such mixtures.

  3. Extraction of actinide and lanthanide complexonates in potassium carbonate-poly(ethylene glycol)-water two-phase aqueous system

    SciTech Connect

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

    1988-09-01

    An extraction system based on poly(ethylene glycol) for preconcentrating, isolating and separating actinides, is proposed. The extraction of actinides and lanthanides in a potassium carbonate-poly(ethylene glycol)-water two-phase aqueous system in the presence of various complexones was studied. Trivalent actinides are quantitatively extracted by poly(ethylene glycol) from potassium carbonate solutions in a system with Xylenol Orange and alizarin complexone. Under these conditions, uranium (VI) and plutonium (IV) are extracted inappreciably into a phase enriched with poly(ethylene glycol), so that they can be separated from trivalent actinides with a separation factor of 10/sup 2/-10/sup 3/. To separate actinides and lanthanides, two complexones were introduced into the system, one of which served as an extractant, and the other as a masking reagent. The best results were obtained for a mixture of Xylenol Orange and hydroxyethylidenediphosphonic acid. The separation coefficients of americium and europium are 4.5-5.6.

  4. Protein-resistant polymer coatings based on surface-adsorbed poly(aminoethyl methacrylate)/poly(ethylene glycol) copolymers.

    PubMed

    Ionov, Leonid; Synytska, Alla; Kaul, Elisabeth; Diez, Stefan

    2010-01-11

    We report on the protein-resistant properties of glass substrates coated with novel copolymers of 2-aminoethyl methacrylate hydrochloride and poly(ethylene glycol) methyl ether methacrylate (AEM-PEG). In comparison to currently available protein-blocking polymer systems, such as poly-l-lysine-poly(ethylene glycol), silane-based poly(ethylene glycol), and poly(ethylene glycol) brushes prepared by surface-initiated polymerization, the proposed AEM-PEG offers the combined advantages of low cost, simplicity of use, and applicability in aqueous solutions. We demonstrate the capability of AEM-PEG to block the surface binding of globular proteins (tubulin), their assemblies (microtubules), and functional motor proteins (kinesin-1). Moreover, we demonstrate the applicability of AEM-PEG for surface patterning of proteins in microfluidic devices.

  5. Noncovalent pegylation by dansyl-poly(ethylene glycol)s as a new means against aggregation of salmon calcitonin.

    PubMed

    Mueller, Claudia; Capelle, Martinus A H; Arvinte, Tudor; Seyrek, Emek; Borchard, Gerrit

    2011-05-01

    During all stages of protein drug development, aggregation is one of the most often encountered problems. Covalent conjugation of poly(ethylene glycol) (PEG), also called PEGylation, to proteins has been shown to reduce aggregation of proteins. In this paper, new excipients based on PEG are presented that are able to reduce aggregation of salmon calcitonin (sCT). Several PEG polymers consisting of a hydrophobic dansyl-headgroup attached to PEGs of different molecular weights have been synthesized and characterized physicochemically. After addition of dansyl-methoxypoly(ethylene glycol) (mPEG) 2 kDa to a 40 times molar excess of sCT resulted in an increase in dansyl-fluorescence and a decrease in 90° light scatter suggesting possible interactions. The aggregation of sCT in different buffer systems in presence or absence of the different dansyl-PEGs was measured by changes in Nile red fluorescence and turbidity. Dansyl-mPEG 2 kDa in a 1:1 molar ratio to sCT strongly reduced aggregation. Reduction of sCT aggregation was also measured for the bivalent dansyl-PEG 3 kDa in a 1:1 molar ratio. Dansyl-mPEG 5 kDa deteriorated sCT aggregation. Potential cytotoxicity and hemolysis were investigated. This paper shows that dansyl-PEGs are efficacious in reducing aggregation of sCT.

  6. Field study of the urinary excretion of ethoxyacetic acid during repeated daily exposure to the ethyl ether of ethylene glycol and the ethyl ether of ethylene glycol acetate.

    PubMed

    Veulemans, H; Groeseneken, D; Masschelein, R; Van Vlem, E

    1987-06-01

    The urinary excretion of ethoxyacetic acid (EAA) was studied in a group of five women daily exposed to the ethyl ether of ethylene glycol (EGEE) and the ethyl ether of ethylene glycol acetate (EGEE-Ac) during 5 d of normal production and 7 d after a 12-d production stop. The mean combined exposure concentration of EGEE and EGEE-Ac (expressed in equivalent weight of EGEE) was 14.0 mg/m3 with occasional slight excursions above the current Belgian occupational exposure limit. The daily combined exposure profiles for EGEE and EGEE-Ac were rather constant during the first observation period, but they tended to decrease during the last week. The urinary EAA excretion clearly increased during the work week. Over the weekends the elimination was far from complete, and even after a prolonged nonexposure period of 12 d traces of the metabolite were still detectable. Based on the observations from the first period, a good linear correlation (r = 0.92) was found between the average exposure over 5 d (14.4 mg/m3) and the EAA excretion at the end of the week (105.7 mg/g creatinine). An EAA estimate of 150 +/- 35 mg/g was found to correspond with repeated 5-d full-shift exposures to the respective occupational exposure limit of EGEE (19 mg/m3) or EGEE-Ac (27 mg/m3).

  7. Injectable biodegradable thermosensitive hydrogel composite for orthopedic tissue engineering. 1. Preparation and characterization of nanohydroxyapatite/poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) hydrogel nanocomposites.

    PubMed

    Fu, Shaozhi; Guo, Gang; Gong, Changyang; Zeng, Shi; Liang, Hang; Luo, Feng; Zhang, Xiaoning; Zhao, Xia; Wei, Yuquan; Qian, Zhiyong

    2009-12-31

    In this study, we synthesized a biodegradable triblock copolymer poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) by ring-opening copolymerization, and nanohydroxyapatite (n-HA) powder was prepared by a hydrothermal precipitation method. The obtained n-HA was incorporated into the PECE matrix to prepare injectable thermosensitive hydrogel nanocomposites. (1)H NMR, FT-IR, XRD, DSC, and TEM were used to investigate the properties of PECE copolymer and n-HA/PECE nanocomposites. The rheological measurements for n-HA/PECE nanocomposites revealed that the gelation temperature was approximately 36 degrees C. The sol-gel-sol transition behavior and phase transition diagrams were recorded through a test tube inverting method. The results showed that n-HA/PECE nanocomposites still had thermoresponsivity like that of PECE thermosensitive hydrogel. The morphology of the nanocomposites was observed by SEM; the results showed that the nanocomposites had a 3D network structure. In addition, the effects of n-HA contents on the properties of n-HA/PECE nanocomposites are also discussed in the paper. From the results, n-HA/PECE hydrogel is believed to be promising for injectable orthopedic tissue engineering due to its good thermosensitivity and injectability.

  8. Degradative properties and cytocompatibility of a mixed-mode hydrogel containing oligo[poly(ethylene glycol)fumarate] and poly(ethylene glycol)dithiol.

    PubMed

    Brink, Kelly S; Yang, Peter J; Temenoff, Johnna S

    2009-02-01

    Our laboratory is currently exploring synthetic oligo(poly(ethylene glycol)fumarate) (OPF)-based biomaterials as a means to deliver fibroblasts to promote regeneration of central/partial defects in tendons and ligaments. In order to further modulate the swelling and degradative characteristics of OPF-based hydrogels, OPF crosslinking via a radically initiated, mixed-mode reaction involving poly(ethylene glycol) (PEG)-diacrylate and PEG-dithiol was investigated. Results demonstrate that mixed-mode hydrogels containing OPF can be formed and that the presence of 20 wt.% PEG-dithiol increases swelling and decreases degradation time vs. 10 wt.% PEG-dithiol and non-thiol-containing hydrogels (20% thiol fold swelling 28.7+/-0.8; 10% thiol fold swelling 11.6+/-1.4; non-thiol 8.7+/-0.2; 20% thiol-containing hydrogels degrade within 15 days in vitro). After encapsulation, tendon/ligament fibroblasts remained largely viable over 8 days of static culture. While the presence of PEG-dithiol did not significantly affect cellularity or collagen production within the constructs over this time period, image analysis revealed that the 20% PEG-dithiol gels did appear to promote cell clustering, with greater values for aggregate area observed by day 8. These experiments suggest that mixed-mode OPF-based hydrogels may provide an interesting alternative as a cell carrier for engineering a variety of soft orthopedic tissues, particularly for applications when it is important to encourage cell-cell contact.

  9. Polystyrene nanoparticles based on poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers.

    PubMed

    Horgan, Adrian; Vincent, Brian

    2003-06-15

    The solubilization of styrene by poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers has been examined. From turbidity measurements the solubility limit of the monomer in the micelles was obtained and the distribution coefficients were evaluated. Dynamic light scattering revealed that below the solubility limit, solubilization leads to a slight increase in micelle size, while above the solubility limit, there is a dramatic increase in particle size and turbidity as oil-in-water emulsions are formed through coalescence of monomer-swollen micelles. Polymerizations carried out below the solubility limit using the graft copolymer micelles as templates resembled microemulsion polymerizations in nature and led to very fine sterically stabilized polystyrene latex particles. Through careful control of the monomer concentration and the polymerization temperature it was possible to obtain spherical nanosize latex particles with similar size to those of the micelle precursors (10 nm) up to 11% monomer by weight. Polymerizations above the solubility limit, on the other hand, showed similarities with emulsion polymerizations and resulted in larger particles with higher polydispersity.

  10. PtIr-WO3 nanostructured alloy for electrocatalytic oxidation of ethylene glycol and ethanol.

    PubMed

    Murawska, Magdalena; Cox, James A; Miecznikowski, Krzysztof

    2014-01-01

    In this article, we characterized tungsten oxide-decorated carbon-supported PtIr nanoparticles and tested it for the electrooxidation reactions of ethylene glycol and ethanol. Phase and morphological evaluation of the proposed electrocatalytic materials are investigated employing various characterization techniques including X-ray diffraction (XRD) and transmission electron microscopy (TEM). Electrochemical diagnostic measurements such as cyclic voltammetry, chronoamperometry, and linear sweep voltammetry revealed that the tungsten oxide-modified PtIr/Vulcan nanoparticles have higher catalytic activity for ethylene glycol and ethanol electrooxidation than that of PtIr/Vulcan. A significant enhancement for electrooxidation of CO-adsorbate monolayers occurred in the presence of a transition metal oxide relative to that of pure PtIr/Vulcan electrocatalyst. The likely reasons for this are modification on the Pt center electronic structure and/or increasing the population of reactive oxo groups at the PtIr/Vulcan electrocatalytic interface in different potential regions.

  11. Dimethyl sulfoxide and ethylene glycol promote membrane phase change during cryopreservation.

    PubMed

    Spindler, R; Wolkers, W F; Glasmacher, B

    2011-01-01

    Fourier transform infrared spectroscopy (FTIR) and cryomicroscopy were used to study the effects of dimethyl sulfoxide and ethylene glycol on cell pellets of human pulmonary microvascular endothelial cells during freezing from 4 degree C to -60 degree C at 1 degree C per min. FTIR analysis showed that membranes undergo a phase change in the presence of cryoprotective agents (CPAs) which was not observed in the absence of CPAs. Cryomicroscopy revealed the formation of intracellular ice and concomitant cell volume changes. Intracellular ice was detected in the majority of the cells both in the presence and absence of CPAs. Membrane phase changes were found to be most pronounced at intermediate concentrations of cryoprotective agents; for dimethyl sulfoxide at around 1 M and for ethylene glycol at around 1.5 M. At those concentrations cell survival after thawing exhibited a maximum. The results indicate that CPAs promote rather than prevent cell dehydration during freezing.

  12. Characterization of Tin/Ethylene Glycol Solar Nanofluids Synthesized by Femtosecond Laser Radiation.

    PubMed

    Torres-Mendieta, Rafael; Mondragón, Rosa; Puerto-Belda, Verónica; Mendoza-Yero, Omel; Lancis, Jesús; Juliá, J Enrique; Mínguez-Vega, Gladys

    2017-05-05

    Solar energy is available over wide geographical areas and its harnessing is becoming an essential tool to satisfy the ever-increasing demand for energy with minimal environmental impact. Solar nanofluids are a novel solar receiver concept for efficient harvesting of solar radiation based on volumetric absorption of directly irradiated nanoparticles in a heat transfer fluid. Herein, the fabrication of a solar nanofluid by pulsed laser ablation in liquids was explored. This study was conducted with the ablation of bulk tin immersed in ethylene glycol with a femtosecond laser. Laser irradiation promotes the formation of tin nanoparticles that are collected in the ethylene glycol as colloids, creating the solar nanofluid. The ability to trap incoming electromagnetic radiation, thermal conductivity, and the stability of the solar nanofluid in comparison with conventional synthesis methods is enhanced. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Spectroscopic and time domain reflectometry studies on acetonitrile - Ethylene glycol binary solutions

    NASA Astrophysics Data System (ADS)

    Mahendraprabu, A.; Kumbharkhane, A. C.; Joshi, Y. S.; Shaikh, S. S.; Kannan, P. P.; Karthick, N. K.; Arivazhagan, G.

    2017-05-01

    Spectroscopic (FTIR and 13C NMR) and time domain reflectometry (in the frequency range from 10 MHz to 25 GHz) studies have been carried out on the binary solutions of acetonitrile (AN) with ethylene glycol (EG). The presence of EG-EG multimers of various orders in neat EG has been confirmed by spectroscopic studies. AN-EG association through the formation of ∁ ≡ N ⋯ H - O , ∁ ≡ N ⋯ H - C(EG) and (EG) C - O ⋯ H - C(AN) hydrogen bonds have been identified using spectral studies. The principal relaxation process of the heteromolecular entities that involve higher order alcohol association in ethylene glycol rich solutions is found to be relatively slower than that in acetonitrile rich solutions in which lower order alcohol association involves in heterointeraction. The angular correlation among the dipoles appears to be described more precisely when the experimental ε∞ values rather than ε∞ =n2 are used for the calculation of geff .

  14. Comparison of conventional freezing and vitrification with dimethylformamide and ethylene glycol for cryopreservation of ovine embryos.

    PubMed

    Varago, F C; Moutacas, V S; Carvalho, B C; Serapião, R V; Vieira, F; Chiarini-Garcia, H; Brandão, F Z; Camargo, L S; Henry, M; Lagares, M A

    2014-10-01

    The aim of this work was to evaluate the efficiency of the cryoprotectants dimethylformamide and ethylene glycol for cryopreservation of ovine embryos using vitrification and conventional freezing. The recovered embryos were distributed randomly in three treatment groups: Gr. 1: conventional freezing (n = 44), Gr. 2: vitrification with ethylene glycol (n = 39) and Gr. 3: vitrification with dimethylformamide (n = 38). Quality of fresh embryos in control group as well as of frozen and vitrified embryos was examined by three methodologies: staining with propidium iodide and Hoechst 33258 and evaluation under fluorescent microscopy, evaluation of re-expansion and hatching rates after culture, and determination of apoptotic index with TUNEL technique. It was established that re-expansion rate in all treatment groups was similar. In the same time, hatching rates were higher in Gr. 1 (40.5%) and Gr. 2 (35.3%) in comparison with Gr. 3 (15.5%, p < 0.05). The number of dead cells in vitrified embryos of Gr. 2 and Gr. 3 was higher (42.6 ± 26.2 and 63.2 ± 34.65, respectively) in comparison with Gr. 1 (conventional freezing, 10.1 ± 8.5, p < 0.05). Embryos vitrified with dimethylformamide included the same quality of apoptotic cells that Gr. 1 (conventional freezing) and fresh embryos. In conclusion, the dimethylformamide and ethylene glycol used as cryoprotectant to vitrify ovine embryos, in the concentrations and exposition time tested in this work, were not as efficient as the conventional freezing for cryopreservation of ovine embryos Thus, the conventional freezing with ethylene glycol was the most efficient method to cryopreserve ovine embryos in comparison with vitrification.

  15. Radiation-grafting of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) onto silicone rubber

    NASA Astrophysics Data System (ADS)

    Flores-Rojas, G. G.; Bucio, E.

    2016-10-01

    Silicone rubber (SR) was modified with a graft of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) using either gamma-radiation or azobisisobutyronitrile (AIBN). The graft efficiency was evaluated as a function of monomer concentration, absorbed dose, reaction temperature, and concentration of AIBN. The hydrophilicity of the grafted films was measured by contact angle and their equilibrium swelling time in ethanol. Additional characterization by infrared (FTIR-ATR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is also reported.

  16. V-structures of ethylene glycol and monoethanolamine in the temperature range of the liquid phase

    NASA Astrophysics Data System (ADS)

    Balabaev, N. K.; Rodnikova, M. N.; Solonina, I. A.; Shirokova, E. V.; Sirotkin, D. A.

    2017-01-01

    Vibration-averaged V-structures for liquid ethylene glycol (EG) and monoethanolamine (MEA) are found in the temperature range of the solvents' liquid phase by means of molecular dynamics. The obtained V-structures' characteristics are compared to X-ray diffraction data on the crystalline phases of these compounds. Good agreement between theoretical and experimental data is observed. The V-structures are compared to that of water.

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

    PubMed

    Selvakumar, P; Suresh, S

    2014-03-01

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

  18. Protective effects of the aqueous extract of Crocus sativus against ethylene glycol induced nephrolithiasis in rats.

    PubMed

    Amin, Bahareh; Feriz, Hanieh Moghri; Hariri, Alireza Timcheh; Meybodi, Naser Tayyebi; Hosseinzadeh, Hossein

    2015-01-01

    This study evaluated the possible protective effect of Crocus sativus L. (saffron) in the treatment of renal calculi. Aqueous extract of saffron (25, 50 and 100 mg/kg, daily) was administered intraperitoneally in two regimens of protective or curative, using male Wistar rats. Urolithiasis was induced by ethylene glycol (% 0.75) in drinking water. Urine was collected for biochemical analysis and the kidneys were prepared for total lipid peroxide and histological evaluation. Ethylene glycol feeding resulted in an increased urine output, renal excretion of oxalate and decreased excretion of citrate and magnesium. Saffron did not show diuretic effect; however, it significantly reduced the elevated urinary oxalate in prophylactic (50 and 100 mg/kg) and curative (100 mg/kg) studies. Only the high dose of prophylactic regimen restored citrate concentration of urine. Increased number of calcium oxalate crystals deposits in the kidney tissue of calculogenic rats was significantly reverted by the prophylactic and high dose of curative saffron treatment. Malondialdehyde (MDA, a lipid peroxidation product) in the kidneys was increased following the lithogenic treatment; however, prophylactic (50, 100 mg/kg) and curative (100 mg/kg) regimens with saffron reduced the elevated levels of MDA. Results in the current study indicate that saffron can protect against ethylene glycol induced calcium oxalate (CaOx) nephrolithiasis. The mechanisms underlying this effect are mediated possibly through effect on the urinary concentration of stone-forming constituents and an antioxidant effect.

  19. Hydrophilization of poly(caprolactone) copolymers through introduction of oligo(ethylene glycol) moieties.

    PubMed

    Wurth, Jonathan J; Blumenthal, Nils R; Shastri, V Prasad

    2014-01-01

    In this study, a new family of poly(ε-caprolactone) (PCL) copolymers that bear oligo(ethylene glycol) (OEG) moieties is described. The synthesis of three different oligo(ethylene glycol) functionalized epoxide monomers derived from 2-methyl-4-pentenoic acid, and their copolymerization with ε-caprolactone (CL) to poly(CL-co-OEG-MPO) copolymers is presented. The statistical copolymerization initiated with SnOct2/BnOH yielded the copolymers with varying OEG content and composition. The linear relationship between feed ratio and incorporation of the OEG co-monomer enables control over backbone functional group density. The introduction of OEG moieties influenced both the thermal and the hydrophilic characteristics of the copolymers. Both increasing OEG length and backbone content resulted in a decrease in static water contact angle. The introduction of OEG side chains in the PCL copolymers had no adverse influence on MC-3TE3-E1 cell interaction. However, changes to cell form factor (Φ) were observed. While unmodified PCL promoted elongated (anisotropic) morphologies (Φ = 0.094), PCL copolymer with tri-ethylene glycol side chains at or above seven percent backbone incorporation induced more isotropic cell morphologies (Φ = 0.184) similar to those observed on glass controls (Φ = 0.151).

  20. Use of ethylene glycol to evaluate gradient performance in gradient-intensive diffusion MR sequences.

    PubMed

    Spees, William M; Song, Sheng-Kwei; Garbow, Joel R; Neil, Jeffrey J; Ackerman, Joseph J H

    2012-07-01

    Imaging a phantom of known dimensions is a widely used and simple method for calibrating MRI gradient strength. However, full-range characterization of gradient response is not achievable using this approach. Measurement of the apparent diffusion coefficient of a liquid with known diffusivity allows for calibration of gradient amplitudes across a wider dynamic range. An important caveat is that the temperature dependence of the liquid's diffusion characteristics must be known, and the temperature of the calibration phantom must be recorded. In this report, we demonstrate that the diffusion coefficient of ethylene glycol is well described by Arrhenius-type behavior across the typical range of ambient MRI magnet temperatures. Because of ethylene glycol's utility as an NMR chemical-shift thermometer, the same (1)H MR spectroscopy measurements that are used for gradient calibration also simultaneously "report" the sample temperature. The high viscosity of ethylene glycol makes it well-suited for assessing gradient performance in demanding diffusion-weighted imaging and spectroscopy sequences. Copyright © 2011 Wiley Periodicals, Inc.

  1. New deuterated oligo(ethylene glycol) building blocks and their use in the preparation of surface active lipids possessing labeled hydrophilic tethers.

    PubMed

    Faragher, Robert J; Schwan, Adrian L

    2008-02-15

    For the introduction of additional analysis protocols of tethered molecules, a method is presented to prepare functionalized, deuterated oligo(ethylene glycols) from ethylene glycol-d4. Partial oligomerization of ethylene glycol-d4 and conversion to ditosylates is accompanied by coupling reactions to prepare doubly benzyl protected oligo(ethylene glycols) with two to five repeating units. The tetramer bearing 16 deuteria was elaborated at both ends to eventually prepare 2,3-di-O-phytanyl-sn-glycerol-1-tetraethylene glycol-d,l-alpha-lipoic acid ester (DPTL), which bears a fully deuterated tetra(ethylene glycol) spacer group. Through linking of functionalized components, an analogue of DPTL possessing an octa(ethylene glycol) spacer group was prepared, both in deuterated and unlabeled form.

  2. Difference of carboxybetaine and oligo(ethylene glycol) moieties in altering hydrophobic interactions: a molecular simulation study.

    PubMed

    Shao, Qing; White, Andrew D; Jiang, Shaoyi

    2014-01-09

    Polycarboxybetaine and poly(ethylene glycol) materials resist nonspecific protein adsorption but differ in influencing biological functions such as enzymatic activity. To investigate this difference, we studied the influence of carboxybetaine and oligo(ethylene glycol) moieties on hydrophobic interactions using molecular simulations. We employed a model system composed of two non-polar plates and studied the potential of mean force of plate-plate association in carboxybetaine, (ethylene glycol)4, and (ethylene glycol)2 solutions using well-tempered metadynamics simulations. Water, trimethylamine N-oxide, and urea solutions were used as reference systems. We analyzed the variation of the potential of mean force in various solutions to study how carboxybetaine and oligo(ethylene glycol) moieties influence the hydrophobic interactions. To study the origin of their influence, we analyzed the normalized distributions of moieties and water molecules using molecular dynamics simulations. The simulation results showed that oligo(ethylene glycol) moieties repel water molecules away from the non-polar plates and weaken the hydrophobic interactions. Carboxybetaine moieties do not repel water molecules away from the plates and therefore do not influence the hydrophobic interactions.

  3. The operation of enzymatic fuel cell fabricated with rationally designed poly(caprolactone-g-ethylene glycol) copolymers.

    PubMed

    Korkut, Seyda; Kilic, Muhammet Samet; Sanal, Timur; Hazer, Baki

    2017-07-01

    This study describes construction of an enzymatic fuel cell comprised of poly(caprolactone-g-ethylene glycol) coated novel glucose oxidase anode and laccase cathode. Rationally designed poly(caprolactone-g-ethylene glycol) containing various poly(ethylene glycol) percentages ranging between 2.67 and 15.04% were synthesized chemically and tested separately for operation of the fuel cell system to achieve the best energy generation. The maximum power density was found to be 80.55μWcm(-2) at 0.91V (vs. Ag/AgCl) in pH5, 100mM citrate buffer (20°C) by the addition of 30mM of glucose from the electrodes coated with 11.34% poly(ethylene glycol) containing polymer with a quantity of 600μg. High poly(ethylene glycol) percentages with more numbers of long poly(ethylene glycol) brushes lead to the creation of a complexity in the polymer morphology and steric hindrance effect for electron transport. The graft copolymer was easily used for the fuel cell system owing to its biocompatible and microporous film morphology. The grafted polymer was able to facilitate enzymatic glucose oxidation and oxygen reduction while simultaneously producing high catalytic electrical currents. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    PubMed

    Munakata, Shinsuke; Hatori, Kuniyuki

    2013-11-01

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

  5. Relative toxicities of pure propylene and ethylene glycol and formulated deicers on plant species

    SciTech Connect

    DuFresne, D.L.; Pillard, D.A.

    1994-12-31

    Propylene and ethylene glycol deicers are commonly used at airports in the US and other countries to remove and retard the accumulation of snow and ice on aircraft. Deicers may not only enter water bodies without treatment, due to excessive storm-related flow, but also may expose terrestrial organisms to high concentrations through surface runoff. Most available toxicity data are for aquatic vertebrates and invertebrate species; this study examined effects on terrestrial and aquatic plants. Terrestrial plant species included both a monocot (rye grass, Lolium perenne) and a dicot (lettuce, Lactuca saliva). Aquatic species included a single cell alga (Selenastrum capricomutum), and an aquatic macrophyte (duckweed, Lemna minor). Glycol deicers were obtained in the formulated mixtures used on aircraft. Pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Parameters measured included germination, root and shoot length, survival, and growth. Formulated deicers, like those used at airports, were generally more toxic than pure chemicals, based on glycol concentration. This greater toxicity of formulated deicers is consistent with results of tests using animal species.

  6. Evaluation of glove material resistance to ethylene glycol dimethyl ether permeation

    SciTech Connect

    Menke, R.; Chelton, C.F.

    1988-08-01

    Some glycol ethers have been reported to cause adverse reproductive effects in exposed male and female workers, and skin absorption has been determined to be an important route of entry of this class of chemicals. Because ethylene glycol dimethyl ether (EGDME) is a possible component of lithium-based primary battery electrolyte systems, a study was undertaken to determine the resistance of various commercially available gloves to permeation of this liquid. The gloves were tested by the ASTM Method F-739-81, and butyl rubber was found to be the most effective barrier to permeation. Further studies determined that the butyl gloves could be reused if they were reconditioned overnight in a vacuum oven at 50 degrees C. When a mixture of ethylene glycol dimethyl ether (30% v/v) and propylene carbonate (70% v/v) was tested, the results indicated that the propylene carbonate retards the permeation of the glycol ether by a factor of 10. This is believed to be caused by the propylene carbonate coating the surface of the butyl membrane to reduce the sorption of EGDME.

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

    PubMed

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

    2014-08-01

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

  8. Aqueous sols of oligo(ethylene glycol) surface decorated polydiacetylene vesicles for colorimetric detection of Pb 2+.

    PubMed

    Narkwiboonwong, Pat; Tumcharern, Gamolwan; Potisatityuenyong, Anupat; Wacharasindhu, Sumrit; Sukwattanasinitt, Mongkol

    2011-01-15

    A series of ethylene glycol (EG), triethylene glycol (3EG) and pentaethylene glycol (5EG) esters of 10,12-pentacosadiynoic acid (PCDA) are synthesized. The glycol ester lipids can be hydrated and well dispersed in water but they cannot form polydiacetylenes upon UV irradiation. They however can be mixed with PCDA up to 30 mol% and polymerized to form blue sols. The mixed polydiacetylene sols show blue to red thermochromic transition with two-stepped transition temperatures. The first transition temperature decreases with the increase of the glycol ester content as well as the length of their chains indicating greater fluidity of the self-assembled structure due to less collaborative hydrogen bonding among the lipid head groups. These mixed polydiacetylene sol prepared from 30 mol% of the penta(ethylene glycol) ester show linear colorimetric response selectively to Pb(2+) in the range of 5-30 μM. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Fast determination of ethylene glycol, 1,2-propylene glycol and glycolic acid in blood serum and urine for emergency and clinical toxicology by GC-FID.

    PubMed

    Hložek, Tomáš; Bursová, Miroslava; Čabalaa, Radomír

    2014-12-01

    A simple, cost effective, and fast gas chromatography method with flame ionization detection (GC-FID) for simultaneous measurement of ethylene glycol, 1,2-propylene glycol and glycolic acid was developed and validated for clinical toxicology purposes. This new method employs a relatively less used class of derivatization agents - alkyl chloroformates, allowing the efficient and rapid derivatization of carboxylic acids within seconds while glycols are simultaneously derivatized by phenylboronic acid. The entire sample preparation procedure is completed within 10 min. To avoid possible interference from naturally occurring endogenous acids and quantitation errors 3-(4-chlorophenyl) propionic acid was chosen as an internal standard. The significant parameters of the derivatization have been found using chemometric procedures and these parameters were optimized using the face-centered central composite design. The calibration dependence of the method was proved to be quadratic in the range of 50-5000 mg mL(-1), with adequate accuracy (92.4-108.7%) and precision (9.4%). The method was successfully applied to quantify the selected compounds in serum of patients from emergency units. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Poly(ethylene glycol) analogs grafted with low molecular weight poly(ethylene imine) as non-viral gene vectors.

    PubMed

    Zhang, Zhenfang; Yang, Cuihong; Duan, Yajun; Wang, Yanming; Liu, Jianfeng; Wang, Lianyong; Kong, Deling

    2010-07-01

    A novel class of non-viral gene vectors consisting of low molecular weight poly(ethylene imine) (PEI) (molecular weight 800 Da) grafted onto degradable linear poly(ethylene glycol) (PEG) analogs was synthesized. First, a Michael addition reaction between poly(ethylene glycol) diacrylates (PEGDA) (molecular weight 258 Da) and d,l-dithiothreitol (DTT) was carried out to generate a linear polymer (PEG-DTT) having a terminal thiol, methacrylate and pendant hydroxyl functional groups. Five PEG-DTT analogs were synthesized by varying the molar ratio of diacrylates to thiols from 1.2:1 to 1:1.2. Then PEI (800 Da) was grafted onto the main chain of the PEG-DTTs using 1,1'-carbonyldiimidazole as the linker. The above reaction gave rise to a new class of non-viral gene vectors, (PEG-DTT)-g-PEI copolymers, which can effectively complex DNA to form nanoparticles. The molecular weights and structures of the copolymers were characterized by gel permeation chromatography, (1)H nuclear magnetic resonance and Fourier transform infrared spectroscopy. The size of the nanoparticles was<200 nm and the surface charge of the nanoparticles, expressed as the zeta potential, was between+20 and+40 mV. Cytotoxicity assays showed that the copolymers exhibited much lower cytotoxicities than high molecular weight PEI (25 kDa). Transfection was performed in cultured HeLa, HepG2, MCF-7 and COS-7 cells. The copolymers showed higher transfection efficiencies than PEI (25 kDa) tested in four cell lines. The presence of serum (up to 30%) had no inhibitory effect on the transfection efficiency. These results indicate that this new class of non-viral gene vectors may be a promising gene carrier that is worth further investigation.

  11. Comparative toxicity of formulated glycol deicers and pure ethylene and propylene glycol to Ceriodaphnia dubia and Pimephales promelas

    SciTech Connect

    Pillard, D.A. )

    1995-02-01

    Airlines use deicers to remove ice and snow from aircraft before flights, and to retard the inflight buildup of these materials. Many of the deicers are formulated mixtures of ethylene glycol (EG) or propylene glycol (PG) and a variety of additives. Because these deicers may be intentionally or accidentally released into aquatic ecosystems, the possibility exists for direct and indirect adverse effects on aquatic organisms. Laboratory studies evaluated the comparative toxicity of formulated glycol deicers and pure materials on the water flea, Ceriodaphnia dubia, and fathead minnow, Pimephales promelas. Acute and short-term chronic tests were performed according to US Environmental Protection Agency (EPA) guidelines. The formulated mixtures were found to be substantially more toxic than either of the pure glycol materials. The 48-h LC50s for C. dubia were 13,140 mg/L and 1,020 mg/L using formulated EG and PG, and 34,400 mg/L and 18,340 mg/L using pure EG and PG, respectively. The 96-h LC50s for P. promelas were 8,050 mg/L and 710 mg/L using formulated EG and PG, and 72,860 mg/L and 55,770 mg/L using pure EG and PG, respectively. Chronic IC25s for C. dubia were 3,960 mg/L and 640 mg/L using formulated EG and PG; 12,310 mg/L and 13,470 mg/L using pure EG and PG. Chronic IC25s for P. promelas were 3,660 mg/L and 110 mg/L using formulated EG and PG; 22,520 mg/L and 6,940 mg/L using pure EG and PG. For airports that have stormwater discharge permits, numerical limits for EG and PG are generally listed; potential toxicity is assumed to be due to the glycol materials. However, other compounds in the mixtures may either contribute substantially to, or in some cases overshadow, the toxicity of the glycol materials.

  12. Increasing the repeating units of ethylene glycol-based dimethacrylates directed toward reduced oxidative stress and co-stimulatory factors expression in human monocytic cells.

    PubMed

    Tamura, Atsushi; Fukumoto, Izumi; Yui, Nobuhiko; Matsumura, Mitsuaki; Miura, Hiroyuki

    2015-03-01

    The ethylene glycol-based dimethacrylates are commonly used in biomaterials and dental restorative materials as a cross-linking agent. In this study, toxic effect of triethylene glycol dimethacrylate (TEGDMA) and poly(ethylene glycol) dimethacrylates (PEG-DMAs) with various ethylene glycol repeating units was investigated in terms of cytotoxicity, oxidative stress, and the expression of co-stimulatory factors in human leukemia cell line (THP-1 cells) to verify the effect of ethylene glycol repeating units. Note that the 1-octanol/water partition coefficient of PEG-based dimethacrylates decreased with increasing the ethylene glycol repeating units, indicating that the hydrophilicity of PEG-DMAs increased with ethylene glycol repeating units. The toxic effect of PEG-DMAs such as cytotoxicity, oxidative stress, and the expression of CD86 in treated THP-1 cells are reduced with increasing the ethylene glycol repeating units in PEG-DMAs. However, the expression of CD54 in treated THP-1 cells was not influenced with the ethylene glycol repeating units and the maximal expression level of CD54 was observed at the concentration range of 2-4 mM for all samples. Accordingly, hydrophilic character of PEG-DMAs with long ethylene glycol chains definitely alleviates the some toxic aspect of PEG-based DMAs. This finding would provide important insight into the design of new biomaterials and dental materials with superior biocompatibility. © 2014 Wiley Periodicals, Inc.

  13. Biotic and abiotic degradation behaviour of ethylene glycol monomethyl ether (EGME).

    PubMed

    Fischer, A; Hahn, C

    2005-05-01

    Glycol ethers are widely used in many processes in the chemical industry. Their high water solubility means they are used as solvents for different purposes (e.g. lacquers and varnishes). Since glycol ethers are known to produce toxic metabolites such as the teratogenic methoxyacetic acid during biodegradation, the biological treatment of glycol ethers can be hazardous. However, using oxidizing agents like hydrogen peroxide could be a feasible option for treating wastewater containing glycol ether. In this study, both-, biodegradation and abiotic oxidation experiments with ethylene glycol monomethyl ether (EGME) as contaminant were performed. The biodegradation experiments were conducted with a synthetic model wastewater containing 15 wt% NaCl and 5000 mgl(-1) of EGME. While experiments with the fungus Aspergillus versicolor resulted in the exhaustive biotic degradation of EGME, the toxic metabolite methoxyacetic acid (MAA) was produced as a 'dead end' product. Sodium hydroxide was added to adjust the decreasing pH caused by the production of MAA. In abiotic degradation experiments with EGME, other degradation products--organic acids and toxic aldehydes, e.g. methoxy acetaldehyde (MALD)--were detected. It must be taken into account that EGME and its biotic and abiotic degradation products are usually not analysed in routine wastewater measurements owing to their physical properties.

  14. Self-assembly of brush-like poly[poly(ethylene glycol) methyl ether methacrylate] synthesized via aqueous atom transfer radical polymerization.

    PubMed

    Hussain, Hazrat; Mya, Khine Yi; He, Chaobin

    2008-12-02

    Self-assembly of brush-like well-defined poly[poly(ethylene glycol) methyl ether methacrylate] homopolymers, abbreviated as P(PEGMA-475) and P(PEGMA-1100) is investigated in aqueous solution by employing dynamic/static light scattering (DLS/SLS) and transmission electron microscopy (TEM), whereas 475 and 1100 is molar mass of the respective PEGMA macromonomer. The mentioned brush-like homopolymers are synthesized by aqueous ATRP at room temperature. The critical association concentration (CAC) of the synthesized polymers in water depends on the length of the PEG side chains but not on the overall molar mass of the polymer. Thus, approximately the same CAC of approximately 0.35 mg/mL is estimated for various P(PEGMA-1100) samples, and approximately 0.7 mg/mL is estimated for P(PEGMA-475) series. All the investigated P(PEGMA-1100) samples form multimolecular micelles in aqueous solution, where the hydrodynamic size (Rh) and the aggregation number (Nagg) of micelles decreases as the molecular weight of P(PEGMA-1100) increases. This can be attributed to the increased steric hindrances between the PEG side chains in corona of micelles formed by higher molar mass P(PEGMA-1100). The tendency of micelle formation by samples of P(PEGMA-475) series is significantly lower than that of P(PEGMA-1100) series, as demonstrated by their significantly higher CAC and micelles of lower Nagg. The Rh of micelles does not depend strongly on polymer concentration, which suggests that these micelles are formed via the closed association model. Micelles formed by P(PEGMA-1100) series slightly shrink with increase in temperature from 25 to 60 degrees C, while those of P(PEGMA-475) series are found to be insensitive to the same temperature variation. Finally, TEM is carried out to visualize the formed micelles after transferring the aqueous solution to carbon film.

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

    PubMed

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

    2008-12-01

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

  16. Effect of poly(ethylene glycol) molecular weight on tensile and swelling properties of oligo(poly(ethylene glycol) fumarate) hydrogels for cartilage tissue engineering.

    PubMed

    Temenoff, Johnna S; Athanasiou, Kyriacos A; LeBaron, Richard G; Mikos, Antonios G

    2002-03-05

    This study was designed to determine the effect of changes in poly(ethylene glycol) (PEG) molecular weight on swelling and mechanical properties of hydrogels made from a novel polymer, oligo(poly(ethylene glycol) fumarate) (OPF), recently developed in our laboratory. Properties of hydrogels made from OPF with initial PEG molecular weights of 860, 3900, and 9300 were examined. The PEG 3900 formulation had a tensile modulus of 23.1 +/- 12.4 kPa and percent elongation at fracture of 53.2 +/- 13.7%; the PEG 9300 formulation had similar tensile properties (modulus: 16.5 +/- 4.6 kPa, elongation: 76.0 +/- 26.4%). However, the PEG 860 gels had a significantly higher modulus (89.5 +/- 50.7 kPa) and a significantly smaller percent elongation at fracture (30.1 +/- 6.4%), when compared with other formulations. Additionally, there were significant differences in percent swelling between each of the formulations. Molecular weight between crosslinks (M(c)) and mesh size were calculated for each OPF formulation. M(c) increased from 2010 +/- 116 g/mol with PEG 860 to 6250 +/- 280 g/mol with PEG 9300. Mesh size calculations showed a similar trend (76 +/- 2 A for PEG 860 to 160 +/- 6 A for PEG 9300). It was also found that these hydrogels could be laminated if a second layer was added before the first had completely crosslinked. Mechanical testing of these laminated gels revealed that the presence of an interfacial area did not significantly alter their tensile properties. These results suggest that the material properties of OPF-based hydrogels can be altered by changing the molecular weight of PEG used in synthesis and that multilayered OPF hydrogel constructs can be produced, with each layer having distinct mechanical properties.

  17. Toxicities of ethylene glycol and ethylene glycol monoethyl ether in Fischer 344/N rats and B6C3F/sub 1/ mice

    SciTech Connect

    Melnick, R.L.

    1984-08-01

    The toxicities of ethylene glycol (EG) and ethylene glycol monoethyl ether (EGEE) were studied in Fischer 344/N rats and B6C3F/sub 1/ mice. In a 13-week study, EG was administered in feed to groups of 10 rats and 10 mice of both sexes at dose levels of 0 (control), 0.32, 0.63, 1.25, 2.5, and 5.0%. Kidney/body weight ratios were elevated in the 2.5 and 5.0% dose groups of male and female rats relative to controls, while serum urea nitrogen and serum creatinine levels were elevated in the two highest dose groups of male rats. Toxic nephrosis and crystal deposits in renal tubules were observed in the 2.5 and 5.0% dose groups of male rats. Crystals were also observed in brains of male rats in the 5.0% dose group. Nephrosis was the only lesion observed in female rats (5.0% dose group). Mild, compound-related lesions were seen in kidneys (nephrosis) and livers (centrilobular degeneration) of male mice in the 2.5 and 5.0% dose groups. Groups of 50 rats and 50 mice of both sexes were administered EGEE by gavage in a 2-year study at dose levels of 0 (control), 0.5, 1.0 and 2.0 g/kg body weight. Gross lesions noted at necropsy indicate that chronic treatment of rats with EGEE at dose levels of 0.5 or 1.0 g/kg body weight caused an apparent enlargement of the adrenal gland in male rats and interfered with the development of spontaneous lesions of the spleen (males and females), pituitary (males and females), testis (males), and subcutaneous tissue in the mammary gland region (females) that commonly occur in the aging Fischer 344/N rat. 12 references, 4 figures, 8 tables.

  18. Dexamethasone-loaded poly(D, L-lactic acid) microspheres/poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) micelles composite for skin augmentation.

    PubMed

    Fan, Min; Liao, Jinfeng; Guo, Gang; Ding, Qiuxia; Yang, Yi; Luo, Feng; Qian, Zhiyong

    2014-04-01

    Soft tissue augmentation using various injectable fillers has gained popularity as more patients seek esthetic improvement through minimally invasive procedures requiring little or no recovery time. The currently available injectable skin fillers can be divided into three categories. With careful assessment, stimulatory fillers are the most ideal fillers. In this study, dexamethasone-loaded poly(D, L-lactic acid) (PLA) microspheres of approximately 90 micro m suspended in poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) micelles were prepared as stimulatory filler for skin augmentation. The biodegradable PECE copolymer can form nano-sized micelles in water, which instantly turns into a non-flowing gel at body temperature due to micellar aggregation. The PECE micelles (making up 90% of composite) served as vehicle for subcutaneous injection were metabolized within 44 days. At the same time, the dexamethasone-loaded PLA microspheres (10% of composite) merely served as stimulus for connective tissue formation. Dexamethasone-loaded PLA microspheres/PECE micelles composite presented great hemocompatibility in vitro. It was demonstrated in the in vive study that the composite was biodegradable, biocompatible, nontoxic and nonmigratory. Histopathological studies indicated that the composite could stimulate collagen regeneration. Furthermore, granuloma, the main complication of the stimulatory fillers, did not appear when the composite was injected into the back of SD rats, because of the dexamethasone controlled release from the composite. All results suggested that dexamethasone-loaded PLA microspheres/PECE micelles composite may be an efficient and promising biomaterial for skin augmentation.

  19. Click chemistry grafting of poly(ethylene glycol) brushes to alkyne-functionalized pseudobrushes.

    PubMed

    Ostaci, Roxana-Viorela; Damiron, Denis; Grohens, Yves; Léger, Liliane; Drockenmuller, Eric

    2010-01-19

    A versatile method for the grafting of azide-terminated polymer chains to alkyne-functionalized pseudobrushes by the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition has been developed. First, poly[(propargyl methacrylate)-r-(glycidyl methacrylate)-r-(methyl methacrylate)] random copolymers with monomer ratios of respectively 27/27/46, 41/31/28, and 45/55/0 were synthesized by RAFT polymerization. Then, dense alkyne-functionalized pseudobrushes were grafted in melt by thermal ring-opening of the glycidyl groups by the silanols from the silicon substrate. Finally, the grafting of tailor-made alpha-methoxy-omega-azido-poly(ethylene glycol)s (M(w) approximately 5000, 20,000, and 50,000 g/mol) by Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition was performed in sealed reactors at 60 degrees C for 72 h using a polymer weight fraction of 10% in tetrahydrofuran and Cu(PPh(3))(3)Br/DIPEA as the catalytic system. Alkyne-functionalized pseudobrushes and poly(ethylene glycol) brushes were characterized by ellipsometry, scanning probe microscopy, and water contact angle measurements. This "grafting-to" approach represents a fast and versatile method to provide thick and homogeneous polymer brushes with a high surface coverage. A major benefit of this strategy is the tunable and versatile tethering of alkyne functionalities to silicon substrates using a straightforward spin-coating procedure.

  20. The Use of Ethylene Glycol to Evaluate Gradient Performance in Gradient-Intensive Diffusion MR Sequences

    PubMed Central

    Spees, William M.; Song, Sheng-Kwei; Garbow, Joel R.; Neil, Jeffrey J.; Ackerman, Joseph J.H.

    2011-01-01

    Imaging a phantom of known dimensions is a widely used and simple method for calibrating MRI gradient strength. However, full-range characterization of gradient response is not achievable using this approach. Measurement of the apparent diffusion coefficient of a liquid with known diffusivity allows for calibration of gradient amplitudes across a wider dynamic range. An important caveat is that the temperature-dependence of the liquid’s diffusion characteristics must be known, and the temperature of the calibration phantom must be recorded. In this report we demonstrate that the diffusion coefficient of ethylene glycol is well-described by Arrhenius-type behavior across the typical range of ambient MRI magnet temperatures. Because of ethylene glycol’s utility as an NMR chemical-shift thermometer, the same 1H MR spectroscopy measurements that are used for gradient calibration also simultaneously “report” the sample temperature. The high viscosity of ethylene glycol makes it well-suited for assessing gradient performance in demanding diffusion-weighted imaging and spectroscopy sequences. PMID:22127787

  1. Preparation and electrochemical performance of gel polymer electrolytes using tri(ethylene glycol) dimethacrylate

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Soo; Shin, Jung-Han; Doh, Chil-Hoon; Moon, Seong-In; Kim, Sang-Pil

    A gel polymer electrolyte (GPE) is prepared from tri(ethylene glycol) dimethacrylate monomer, benzoyl peroxide, and 1.0 M LiPF 6/ethylene carbonate:diethyl carbonate (1:1 vol.%). The LiCoO 2|graphite cells are assembled and their electrochemical properties are evaluated at various current densities and temperatures. The viscosity of the precursor containing 5 vol.% tri(ethylene glycol) dimethacrylate monomer is around 4.6 mPa s. The ionic conductivity of the gel polymer electrolyte at 20 °C is around 5.9×10 -3 S cm -1. The gel polymer electrolyte has good electrochemical stability up to 4.5 V versus Li/Li +. The capacity of the cell at the 1.0 C rate is 89% of the discharge capacity at the 0.2 C rate. The capacity of the cell at temperature of -10 °C is 81% of the discharge capacity at 20 °C. The discharge capacity of the cell with gel polymer electrolyte is stable with charge-discharge cycling.

  2. Analysis of gamma-hydroxybutyric acid, DL-lactic acid, glycolic acid, ethylene glycol and other glycols in body fluids by a direct injection gas chromatography-mass spectrometry assay for wide use.

    PubMed

    Van Hee, Paul; Neels, Hugo; De Doncker, Mireille; Vrydags, Nicolas; Schatteman, Katinka; Uyttenbroeck, Wim; Hamers, Nicole; Himpe, Dirk; Lambert, Willy

    2004-01-01

    Analysis of blood of severely intoxicated patients always requires prompt investigation. Diagnosis of intoxication with ethylene glycol, gamma-hydroxybutyric acid or D-lactic acid takes hours, since several different procedures are required. Rapid derivatization of the common hydroxyl function may resolve this analytical problem. Here we describe a fast method for the simultaneous measurement of ethylene glycol, glycolic acid, gamma-hydroxybutyric acid and racemic lactic acid. Only 20 microl of serum, plasma or urine are required for immediate derivatization at 70 degrees C with 750 microl of bis-N,O-trimethylsilyl trifluoroacetamide after adding 20 microl of internal standard solution (1,3-propylene glycol) and 20 microl of the catalyst dimethylformamide. After centrifugation an aliquot is transferred to a gas chromatographic system and analyzed with electron-impact mass spectrometry in selective ion monitoring mode. The derivatized acids and ethylene glycol are well separated and detected with a limit of detection ranging from 0.12 mg/l for ethylene glycol to 0.95 mg/l for gamma-hydroxybutyric acid, while the limit of quantification ranged from 0.4 mg/l for ethylene glycol to 3.15 mg/l for gamma-hydroxybutyric acid. The method is linear from 0.5 to 1800 mg/l blood for ethylene glycol, from 0.7 to 1200 mg/l for lactic acid, from 1.2 to 1800 mg/l for glycolic acid, and from 3.2 to 200 mg/l for gamma-hydroxybutyric acid, with analytical recoveries, accuracy, day-to-day and within-day precision well within the required limits. Total analysis time with one calibrator was 30 min, derivatization time included. This method is very suitable for emergency toxicology, since several toxic substances can be quantified simultaneously in a fast and sensitive manner.

  3. 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. © 2013.

  4. Hydrophilic poly (ethylene glycol) capped poly (lactic-co-glycolic) acid nanoparticles for subcutaneous delivery of insulin in diabetic rats.

    PubMed

    S, Saravanan; S, Malathi; P S L, Sesh; S, Selvasubramanian; S, Balasubramanian; V, Pandiyan

    2017-02-01

    The aim of the present study is to evaluate the effect of insulin loaded poly(ethylene glycol) capped poly(lactic-co-glycolic)acid nanoparticles (ISPPLG NPs) by subcutaneous administration in diabetic rats. A series of biodegradable low molecular weight PLGA [90/10 (PLG2) and 80/20 (PLG4)] copolymers were synthesized by melt polycondensation and their ISPPLG NPs were synthesized by water-oil-water (W/O/W) emulsion solvent evaporation method. The PLGA copolymers and their nanoparticles were characterized. The maximum encapsulation efficiency of ISPPLG4 NPs is 66% and the diameter of the nanoparticles is about 140nm. The in-vivo studies of ISPPLG NPs carried out in diabetic rats by subcutaneous administration show considerable reduction in serum glucose level along with partial restoration of tissue defense systems. Histopathological studies reveal that ISPPLG NPs could restore the damages caused by oxidants during hyperglycaemia. The subcutaneous administration of ISPPLG4 NPs is thus an effective method of reducing hyperglycaemia associated complications.

  5. Assessment of the genotoxicity of three cryoprotectants used for human oocyte vitrification: dimethyl sulfoxide, ethylene glycol and propylene glycol.

    PubMed

    Aye, M; Di Giorgio, C; De Mo, M; Botta, A; Perrin, J; Courbiere, B

    2010-07-01

    Vitrification requires high concentrations of cryoprotectants that may induce long-term toxic effects on cells. The aim of this study was to evaluate the possible genotoxicity of three cryoprotectants extensively used for oocyte vitrification: dimethyl sulfoxide (DMSO), ethylene glycol (EG) and propylene glycol (PROH). For this purpose, a Chinese Hamster Ovary cell line (CHO), commonly used in genetic toxicology, was selected as an in vitro biological model to assess both the induction of DNA strand-breaks as identifiable by the alkaline comet assay and the persistence of chromosomal damages (micronuclei) as analyzed by the micronucleus assay. Results showed that DMSO was not genotoxic. EG did not exert direct genotoxic activity, however EG exhibited significant genotoxic and clastogenic activities in the presence of an external cytochrome-based P450 oxidation system (S9 Mix). PrOH produced in vitro DNA-damage leading to chromosome mutations in the presence and absence of the S9 Mix. These results showed that high concentrations of EG and PrOH could induce in vitro chromosomal damage in eukaryotic cells.

  6. DEVELOPMENT OF A PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR ETHYLENE GLYCOL AND ITS MAJOR METABOLITE, GLYCOLIC ACID, IN RATS AND HUMANS

    SciTech Connect

    Corley, Rick A.; Bartels, M J.; Carney, E W.; Weitz, Karl K.; Soelberg, Jolen J.; Gies, Richard A.; Thrall, Karla D.

    2005-05-19

    An extensive database on the toxicity and modes of action of the major industrial chemical, ethylene glycol (EG), has been developed over the past several decades. These studies have consistently identified the kidney as a primary target organ, with rats being more sensitive than mice and males more sensitive than females following chronic exposure. Renal toxicity has been associated with the terminal metabolite, oxalic acid which can precipitate with calcium to form crystals. EG also induces developmental toxicity, although these effects appear to require high-doses or accelerated dose-rates, and have been reported only in rats and mice. The developmental toxicity of EG has been attributed to the intermediate metabolite, glycolic acid (GA). The developmental toxicity of EG has been the subject of extensive research and regulatory review in recent years. Therefore, a physiologically based pharmacokinetic (PBPK) model was developed to integrate the extensive mode of action and pharmacokinetic data on EG and GA for use in developmental risk assessment. Metabolic rate constants and partition coefficients for EG and GA were estimated from in vitro studies. Other biochemical constants were optimized from appropriate in vivo pharmacokinetic studies. The resulting PBPK model includes inhalation, oral, dermal, intravenous and subcutaneous routes of administration. Metabolism of EG and GA were described in the liver with elimination via the kidneys. Several rat and human metabolism studies were used to validate the resulting PBPK model. Consistent with these studies, simulations indicated that the metabolism of EG to GA was essentially first-order (linear) up to 2500 mg/kg/day while the metabolism of GA saturated between bolus ethylene glycol doses of 200 and 1000 mg/kg/day. This saturation results in non-linear increases in blood GA concentrations, correlating with the developmental toxicity of EG. Pregnancy had no effect on maternal EG and GA kinetics over a broad dose

  7. The complexity of Orion: an ALMA view. II. gGg'-ethylene glycol and acetic acid

    NASA Astrophysics Data System (ADS)

    Favre, C.; Pagani, L.; Goldsmith, P. F.; Bergin, E. A.; Carvajal, M.; Kleiner, I.; Melnick, G.; Snell, R.

    2017-07-01

    We report the first detection and high angular resolution (1.8″× 1.1″) imaging of acetic acid (CH3COOH) and gGg'-ethylene glycol (gGg'(CH2OH)2) toward the Orion Kleinmann-Low (Orion-KL) nebula. The observations were carried out at 1.3 mm with ALMA during Cycle 2. A notable result is that the spatial distribution of the acetic acid and ethylene glycol emission differs from that of the other O-bearing molecules within Orion-KL. While the typical emission of O-bearing species harbors a morphology associated with a V-shape linking the hot core region to the compact ridge (with an extension toward the BN object), the emission of acetic acid and ethylene glycol mainly peaks at about 2'' southwest from the hot core region (near sources I and n). We find that the measured CH3COOH:aGg'(CH2OH)2 and CH3COOH:gGg'(CH2OH)2 ratios differ from those measured toward the low-mass protostar IRAS 16293-2422 by more than one order of magnitude. Our best hypothesis to explain these findings is that CH3COOH, aGg'(CH2OH)2, and gGg'(CH2OH)2 are formed on the icy surface of grains and are then released into the gas-phase via co-desorption with water, by way of a bullet of matter ejected during the explosive event that occurred in the heart of the nebula about 500-700 yr ago.

  8. Ru-Containing Magnetically Recoverable Catalysts: A Sustainable Pathway from Cellulose to Ethylene and Propylene Glycols.

    PubMed

    Manaenkov, Oleg V; Mann, Joshua J; Kislitza, Olga V; Losovyj, Yaroslav; Stein, Barry D; Morgan, David Gene; Pink, Maren; Lependina, Olga L; Shifrina, Zinaida B; Matveeva, Valentina G; Sulman, Esther M; Bronstein, Lyudmila M

    2016-08-24

    Biomass processing to value-added chemicals and biofuels received considerable attention due to the renewable nature of the precursors. Here, we report the development of Ru-containing magnetically recoverable catalysts for cellulose hydrogenolysis to low alcohols, ethylene glycol (EG) and propylene glycol (PG). The catalysts are synthesized by incorporation of magnetite nanoparticles (NPs) in mesoporous silica pores followed by formation of 2 nm Ru NPs. The latter are obtained by thermal decomposition of ruthenium acetylacetonate in the pores. The catalysts showed excellent activities and selectivities at 100% cellulose conversion, exceeding those for the commercial Ru/C. High selectivities as well as activities are attributed to the influence of Fe3O4 on the Ru(0)/Ru(4+) NPs. A facile synthetic protocol, easy magnetic separation, and stability of the catalyst performance after magnetic recovery make these catalysts promising for industrial applications.

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

    PubMed

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

    2013-11-01

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

  10. Ethylene glycol, but not DMSO, could replace glycerol inclusion in soybean lecithin-based extenders in ram sperm cryopreservation.

    PubMed

    Najafi, Abouzar; Daghigh-Kia, Hossein; Dodaran, Hossein Vaseghi; Mehdipour, Mahdieh; Alvarez-Rodriguez, Manuel

    2017-02-01

    The aim of this study was to evaluate the effects of glycerol, ethylene glycol or DMSO in a soybean lecithin extender for freezing ram semen. In this study, 20 ejaculates were collected from four Ghezel rams and diluted with soybean lecithin extender with glycerol (7%), ethylene glycol (3%, 5% and 7%) or DMSO (3%, 5% and 7%). Sperm motility (CASA), membrane integrity (HOS test), viability, total abnormality, mitochondrial activity (Rhodamine 123) and apoptotic features (Annexin V/Propidium iodide) were assessed after thawing. There was no significant difference between glycerol and ethylene glycol at different concentrations (3% and 5%) regarding sperm total and progressive motility, viability, and membrane integrity. The least percentages of mitochondrial functionality were observed in samples frozen with all different DMSO concentrations tested (P<0.05). Moreover, the percentage of post-thawed dead sperm was the greatest for all the DMSO concentrations compared with other groups (P<0.05). Thus, DMSO had an adverse effect on the post thaw ram sperm parameters. In contrast, ethylene glycol could be a desirable substitute of glycerol in the freezing extender, in view of similar results obtained in post-thaw quality of ram semen cryopreserved in a soybean lecithin extender. We propose that glycerol in a soybean lecithin based extender could be replaced by ethylene glycol at 3% or 5% concentrations. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Electrodeposition of Fe3O4 layer from solution of Fe2(SO4)3 with addition ethylene glycol

    NASA Astrophysics Data System (ADS)

    Dahlan, Dahyunir; Asrar, Allan

    2016-03-01

    The electrodeposition of Fe3O4 layer from the solution Fe2(SO4)3 with the addition of ethylene glycol on Indium Tin Oxide (ITO) substrate has been performed. The electrodeposition was carried out using a voltage of 5 volts for 120 seconds, with and without the addition of 2% wt ethylene glycol. Significant effects of temperature on the resulting the samples is observed when they are heated at 400 °C. Structural characterization using X-ray diffraction (XRD) shows that all samples produce a layer of Fe3O4 with particle size less than 50 nanometers. The addition of ethylene glycol and the heating of the sample causes a shrinkage in particle size. The scanning electron microscopy (SEM) characterization shows that Fe3O4 layer resulting from the process of electrodeposition of Fe2(SO4)3 without ethylene glycol, independent of whether the sample is heated or not, is uneven and buildup. Layer produced by the addition of ethylene glycol without heating produces spherical particles. On contrary, when the layer is heated the spherical particles transform to irregularly-shaped particles with smaller size.

  12. Simultaneous and cost-effective determination of ethylene glycol and glycolic acid in human serum and urine for emergency toxicology by GC-MS.

    PubMed

    Hložek, Tomáš; Bursová, Miroslava; Čabala, Radomír

    2015-02-01

    A simple, cost-effective, and fast gas chromatography method with mass spectrometry detection (GC-MS) for simultaneous measurement of ethylene glycol, 1,2-propylene glycol and glycolic acid was developed and validated for clinical toxicology purposes. Successful derivatization of glycolic acid with isobutyl chloroformate was achieved directly in serum/urine while glycols are simultaneously derivatized by phenylboronic acid. The entire sample preparation procedure is completed within 10 min. The assay was proved to be quadratic in the range of 50 to 5000 mgL(-1) with adequate accuracy (96.3-105.8%) and precision (CV ≤ 8.9%). The method was successfully applied to quantify the selected compounds in serum of patients from emergency units and the results correlated well with parallel GC-FID measurements (R(2) 0.9933 for ethylene glycol and 0.9943 for glycolic acid). Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  13. Actuator based on sulfonated comb copolymer of poly (ethylene-co-vinyl alcohol) grafted by poly (ethylene glycol)

    NASA Astrophysics Data System (ADS)

    Gong, Guifen; Li, Lei; Zhang, Yujun

    2007-07-01

    Comb copolymer consisting of poly (ethylene-co-vinyl alcohol) (EVAL) as backbone and poly (ethylene glycol) (PEG) as side chains (EVAL-g-PEG) has been synthesized, then it was sulfonated by 1,3-propane sultone to get the final ionomer (EVAL-g-SPEG), and ionic polymer-metal composite (IPMC) based on EVAL-g-SPEG was prepared through electroless deposition of platinum onto the surfaces of EVAL-g-SPEG membrane. The graft copolymers were characterized with respect to molecular weight using gel permeation chromatography (GPC) and composition using 1H-NMR. The results showed that the No. of PEG graft of the side chains is n=1, 2 and others. Thermal properties were examined by DSC and TG. The melt temperature (T m) and glass transition temperature (T g) of the comb copolymer increase with the increasing length and the number of the side chains. Moreover, the deformation performance of IPMC material was tested and its results show that the starting response voltage of IPMC actuator decreases with the increasing IEC value. On the other hand, the starting response voltage increases with the decreased side chain length. The IPMC with n=2 side chain length of PEG has the maximum tip displacement, and the maximum tip displacement of IPMC membrane generally decreases with the side chain length of EVAL-g-SPEG. This feature may be the reflection of two opposite effects, namely the decreasing ion densities and increasing water sorption of the membrane.

  14. Oligo(ethylene glycol)-modified β-cyclodextrin-based polyrotaxanes for simultaneously modulating solubility and cellular internalization efficiency.

    PubMed

    Tamura, Atsushi; Ohashi, Moe; Yui, Nobuhiko

    We developed stimuli-labile polyrotaxanes (PRXs) composed of β-cyclodextrin (β-CD), Pluronic as an axle polymer, and acid-cleavable N-triphenylmethyl groups as bulky stopper molecules, and found that the PRXs are potent therapeutics for Niemann-Pick type C disease, because the PRX can effectively reduce intracellular cholesterol through the intracellular release of threaded β-CDs. In general, the PRXs need to be chemically modified with hydrophilic functional groups because PRXs are not soluble in aqueous media. Herein, four series of oligo(ethylene glycol)s (OEGs) with different ethylene glycol repeating unit (2 or 3) and chemical structure of OEG terminal (hydroxy or methoxy) were modified onto the threaded β-CDs in PRX. The effects of the structure of OEG on the aqueous solubility, toxicity, and cellular internalization efficiency of OEG-modified PRXs were investigated to optimize the chemical structure of OEG. The hydroxy-terminated OEG-modified PRXs showed excellent solubility in aqueous media and no toxicity, regardless of the number of ethylene glycol repeating units. In the case of the methoxy-terminated OEG-modified PRXs, sufficient solubility in aqueous media and negligible toxicity were observed when the number of ethylene glycol repeating units was 3, while low solubility and toxicity were observed when the ethylene glycol repeating unit was 2. Additionally, cellular uptake levels of methoxy-terminated OEG-modified PRXs in RAW264.7 cells were higher than those of hydroxy-terminated OEG-modified PRXs. Consequently, the chemical structure of the OEG strongly affects the chemical and biological properties of the PRXs, and that a methoxy-terminated OEG with 3 ethylene glycol repeating units is the most preferable modification of PRXs, since the resultant PRX is sufficiently soluble in aqueous media, non-toxic, and possesses high cellular internalization efficiency.

  15. Reversible subacute ethylene glycol monomethyl ether toxicity associated with microfilm production: a case report.

    PubMed

    Cohen, R

    1984-01-01

    The first reported case of a possible toxic effect of ethylene glycol monomethyl ether (EGME) exposure in the microfilm manufacturing industry is described. Reversible subjective central nervous system complaints and asymptomatic hematopoietic effects occurred following inhalation and skin exposure to EGME. Hematopoietic changes occurred at airborne levels which have been associated with reproductive and teratogenic effects in other studies. This finding leads to a recommendation for further research to determine whether or not hematopoietic medical surveillance can provide an indication of not only EGME hematopoietic effects but also an indication of sufficient EGME exposure to affect human reproduction and fetal development.

  16. Investigation on thermo physical characteristics of ethylene glycol based Al:ZnO nanofluids

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    The present work describes the experimental aspects of viscosity and thermal conductivity characteristics of nanofluids. Aluminium doped zinc oxide nanostructures were synthesized by chemical precipitation method. Ultrasonic technique is used to disperse the nanostructures in ethylene glycol. Structural and morphological properties of Al doped ZnO nanostructures are characterized using X-ray diffractometer and scanning electron microscopic technique. The effect of concentration and temperature on thermo-physical properties of Al/ZnO nanofluids is also investigated. The experimental results showed there is enhancement in thermal conductivity with rise in temperature which can be utilized for coolant application.

  17. On the structures of ethylene glycol, monoethanolamine, and ethylenediamine in the liquid phase

    NASA Astrophysics Data System (ADS)

    Balabaev, N. K.; Kraevskii, S. V.; Rodnikova, M. N.; Solonina, I. A.

    2016-05-01

    Characteristics of instant (I) and frozen (F) structures of ethylene glycol (EG), monoethanolamine (MEA), and ethylenediamine (ED) are determined by means of molecular dynamics in the temperature range of 268-443 K. Radial distribution functions are obtained and compared for the I- and F-structures of fluids. Coordination numbers of molecules are calculated and the energies of intermolecular hydrogen bonds are estimated for the studied compounds. The greatest difference between the I- and F-structures is observed in ED, and the least difference is observed in EG. The F-structures are compared to the crystal structures of the studied compounds.

  18. Viscosity of copper oxide nanoparticles dispersed in ethylene glycol and water mixture

    SciTech Connect

    Namburu, Praveen K.; Kulkarni, Devdatta P.; Das, Debendra K.; Misra, Debasmita

    2007-11-15

    Nanofluids are new kinds of fluids engineered by dispersing nanoparticles in base fluids. This paper presents an experimental investigation of rheological properties of copper oxide nanoparticles suspended in 60:40 (by weight) ethylene glycol and water mixture. Nanofluids of particle volume percentage ranging from 0% to 6.12% were tested. The experiments were carried over temperatures ranging from -35 C to 50 C to demonstrate their applicability in cold regions. For the particle volume concentrations tested, nanofluids exhibited Newtonian behavior. An experimental correlation was developed based on the data, which relates viscosity with particle volume percent and the nanofluid temperature. (author)

  19. Effectiveness of ethylene glycol bis (2-aminoethyl ether) tetraacetic acid (EGTA) against cerium toxicity.

    PubMed

    Shrivastava, Sadhana; Mathur, R

    2004-09-01

    Therapeutic efficacy of EGTA (ethylene glycol bis (2-aminoethyl ether) tetraacetic acid) against cerium intoxicated mice was studied. Administration of cerium showed significant decrease in haemoglobin percentage, RBC counts and blood glucose level with an increase in the activity of serum transaminases and WBC counts. Decrease in the activity of alkaline phosphatase and glycogen content was noted in liver and kidney after cerium exposure. Light and electron microscopical investigations showed that these changes were recouped considerably with the administration of EGTA suggesting its therapeutic efficacy against cerium toxicity.

  20. Preparation of polyion complex micelles from poly(ethylene glycol)-block-polyions.

    PubMed

    Bayó-Puxan, Núria; Dufresne, Marie-Hélène; Felber, Arnaud E; Castagner, Bastien; Leroux, Jean-Christophe

    2011-12-10

    Polyion complex micelles (PICMs) arise from the spontaneous self-assembly of ionic polymers of opposite charges to form a condensate that is dispersed in aqueous media by a hydrophilic segment, usually poly(ethylene glycol) (PEG), present on at least one of the two ionic polymers. PICMs are used for many applications, especially drug delivery. This protocol paper describes the preparation by atom transfer radical polymerization (ATRP) of diblock copolymers of PEG bearing either positive or negative charges, both of which have been shown to form PICMs. Furthermore, methods of preparation and characterization of PICMs loaded with nucleic acid drugs are presented.

  1. Rheological non-Newtonian behaviour of ethylene glycol-based Fe2O3 nanofluids.

    PubMed

    Pastoriza-Gallego, María Jose; Lugo, Luis; Legido, José Luis; Piñeiro, Manuel M

    2011-10-25

    The rheological behaviour of ethylene glycol-based nanofluids containing hexagonal scalenohedral-shaped α-Fe2O3 (hematite) nanoparticles at 303.15 K and particle weight concentrations up to 25% has been carried out using a cone-plate Physica MCR rheometer. The tests performed show that the studied nanofluids present non-Newtonian shear-thinning behaviour. In addition, the viscosity at a given shear rate is time dependent, i.e. the fluid is thixotropic. Finally, using strain sweep and frequency sweep tests, the storage modulus G', loss modulus G″ and damping factor were determined as a function of the frequency showing viscoelastic behaviour for all samples.

  2. A fully biocompatible poly(ethylene glycol)-gold plasmonic crystal for optical sensing

    NASA Astrophysics Data System (ADS)

    Kwon, Hyunsoo; Ryu, Shinyoung; Lee, Soonil; Kim, Sunghwan

    2015-09-01

    A significant challenge in nano and biophotonics is to demonstrate fully biocompatible nano-optics devices that can perform biofunctions in vivo. Here we present a scalable, cost-effective, and large-area nanofabrication method for creating a quasi-3D plasmonic crystal using poly(ethylene glycol) (PEG) and gold (Au), both biocompatible materials. The plasmonic crystal was prepared by depositing an Au layer on the upper hemisphere of the replicated PEG nanospheres array. Additionally we demonstrated that the fabricated plasmonic crystal can behave as a label-free glucose sensor with sensitivity and figure-of-merit values comparable to other plasmonic crystal based sensors.

  3. Patterning protein molecules on poly(ethylene glycol) coated Si(111).

    PubMed

    Jun, Yongseok; Cha, Taewoon; Guo, Athena; Zhu, X-Y

    2004-08-01

    We demonstrate spatially localized immobilization of protein molecules on high-density poly(ethylene glycol) (PEG) coated Si(111). Patterns of HO- and CH3O-terminated PEG regions are formed on silicon surfaces based on soft lithography techniques and an efficient reaction between alcohol functional groups and chlorine-terminated silicon. Activation of the HO-terminated PEG brush is achieved via either partial oxidation to form aldehyde groups or via attachment of efficient leaving groups. Protein molecules are covalently immobilized to these activated regions on the PEG/Si surface.

  4. Hydrogen bonds in ethylene glycol, monoethanolamine, and ethylenediamine complexes with water

    NASA Astrophysics Data System (ADS)

    Krest'yaninov, M. A.; Titova, A. G.; Zaichikov, A. M.

    2017-02-01

    The structures of ethylene glycol, aminoethanol, and ethylenediamine complexes with water and the formation of hydrogen bonds of different types are optimized using the B3LYP hybrid functional and the aug-CC-pVTZ basis. The parameters of the hydrogen bonds, their energies of interaction, and their oscillation frequencies are calculated, and NBO and QTAIM analyses are performed. The order of hydrogen bonds according to strength is obtained: O-HW···N > O-HW···O > O-H···OW.

  5. Investigation on thermo physical characteristics of ethylene glycol based Al:ZnO nanofluids

    SciTech Connect

    Kiruba, R. E-mail: drkingson@karunya.edu; George, Ritty; Gopalakrishnan, M.; Kingson Solomon Jeevaraj, A.

    2015-06-24

    The present work describes the experimental aspects of viscosity and thermal conductivity characteristics of nanofluids. Aluminium doped zinc oxide nanostructures were synthesized by chemical precipitation method. Ultrasonic technique is used to disperse the nanostructures in ethylene glycol. Structural and morphological properties of Al doped ZnO nanostructures are characterized using X-ray diffractometer and scanning electron microscopic technique. The effect of concentration and temperature on thermo-physical properties of Al/ZnO nanofluids is also investigated. The experimental results showed there is enhancement in thermal conductivity with rise in temperature which can be utilized for coolant application.

  6. Reaction mechanism of ethylene glycol decomposition on Pt model catalysts: A density functional theory study

    NASA Astrophysics Data System (ADS)

    Lv, Cun-Qin; Yang, Bo; Pang, Xian-Yong; Wang, Gui-Chang

    2016-12-01

    Understanding and controlling bond beak sequence is important in catalytic processes. The DFT-GGA method combined with slab model was performed to study the ethylene glycol decomposition on various Pt model catalysts such as close-packed Pt(111), stepped Pt(211) and a more open one, Pt(100). Calculation results show that the adsorption energies of ethylene glycol and other decomposition species depend on the coordination number of surface atom, that is, low coordination number correspond to high adsorption energy. Moreover, it was found that final products of ethylene glycol decomposition are CO and H2 on all model catalysts, but the reaction mechanism varies: On Pt(111), the first step is Osbnd H bond scission, followed by Csbnd H bond cleavage, namely C2H6O2 → HOCH2CH2O + H → HOCH2CHO + 2H→ HOCH2CO +3H → OCH2CO + 4H → OCHCO + 5H → CO + HCO + 5H → 2CO + 6H→ 2CO + 3H2; On Pt(211) and Pt(100), however, it is a second Osbnd H bond cleavage that follows the initial Osbnd H bond scission, that is, C2H6O2 → HOCH2CH2O + H → OCH2CH2O + 2H → OCHCH2O + 3H → OCHCHO + 4H → 2HCO + 4H → 2CO + 6H → 2CO + 3H2 on Pt(211), and C2H6O2 →HOCH2CH2O+ H → OCH2CH2O + 2H→OCHCH2O+3H→OCCH2O+4H→CO+H2CO+4H→CO+HCO+5H→2CO+6H→2CO+3H2 on Pt(100) For the catalytic order of ethylene glycol to form H2, it may be determined based on the rate-controlling step, and it is Pt(111) > Pt(211) > Pt(100).

  7. Magnetohydrodynamic flow of water/ethylene glycol based nanofluids with natural convection through a porous medium

    NASA Astrophysics Data System (ADS)

    Zeeshan, A.; Ellahi, R.; Hassan, M.

    2014-12-01

    In this study, the natural convection boundary layer flow along with inverted cone, magnetic and heat generation on water and ethylene glycol based nanofluids is considered by means of variable wall temperature. Porous medium is also taken into account. The physical problem is first modeled and then the governing equations are transformed into nonlinear ordinary differential equations under the assumptions of the Boussinesq approximation. Analytical solutions of nonlinear coupled equations are obtained by the homotopy analysis method. Correlation of skin friction and heat transfer rate corresponding to active parameters is also presented. Obtained results are illustrated by graphs and tables in order to see the effects of physical parameters.

  8. Thermo-reversible gelation of atactic poly(methyl methacrylate) in poly(ethylene glycol) oligomers.

    PubMed

    Gao, Yun; Yu, Chunhong; Chen, Minzhi; Wang, Xiaoliang; Zhou, Dongshan; Xue, Gi

    2013-04-01

    The temperature-concentration behavior of physical gel by atactic poly(methyl methacrylate) (aPMMA) in poly(ethylene glycol) oligomer (PEG400) was investigated. A liquid-liquid demixing interferes with a glass transition during cooling. The combination of demixing and T g leads to the formation of amorphous gels at low temperature. We suggest that the gelation of aPMMA/PEG400 is a glassy gel, in which short-range attractive depletion interaction in the polymer/oligomer system was the driving force at molecular level.

  9. Surface characterization of poly(L-lactic acid)-methoxy poly(ethylene glycol) diblock copolymers by static and dynamic contact angle measurements, FTIR, and ATR-FTIR.

    PubMed

    Mert, O; Doganci, E; Erbil, H Y; Demir, A S

    2008-02-05

    The surface composition and surface free energy properties of two types of amphiphilic and semicrystalline diblock copolymers consisting of poly(L-lactic acid) coupled to (methoxy poly(ethylene glycol) (PLLA-MePEG) having differing block lengths of PEG were investigated by using static and dynamic contact angle measurements, transmission Fourier infrared spectroscopy (FTIR), and attenuated total reflection spectroscopy (ATR-FTIR) and compared with results obtained from PLLA and MePEG homopolymers. The contact angle results were evaluated by using the van Oss-Good method (acid-base method), and it was determined that the Lewis base surface tension coefficient (gamma-) of the copolymers increased with an increase of the PEG molar content at the copolymer surface. This result is in good agreement with the transmission FTIR and ATR-FTIR results but not proportional to them, indicating that the surfaces of the copolymers are highly mobile and that the molecular rearrangement takes place upon contact with a polar liquid drop. The dynamic contact angle measurements showed that the strong acid-base interaction between the oxygen atoms in the copolymer backbone of the relatively more hydrophilic PEG segments with the Lewis acidic groups of the polar and hydrogen-bonding water molecules enabled the surface molecules to restructure (conformational change) at the contact area, so that the PEG segments moved upward, whereas the apolar methyl pendant groups of PLLA segments buried downward.

  10. Nonviral Plasmid DNA Carriers Based on N,N'-Dimethylaminoethyl Methacrylate and Di(ethylene glycol) Methyl Ether Methacrylate Star Copolymers.

    PubMed

    Mendrek, Barbara; Sieroń, Łukasz; Żymełka-Miara, Iwona; Binkiewicz, Paulina; Libera, Marcin; Smet, Mario; Trzebicka, Barbara; Sieroń, Aleksander L; Kowalczuk, Agnieszka; Dworak, Andrzej

    2015-10-12

    Star polymers with random and block copolymer arms made of cationic N,N'-dimethylaminoethyl methacrylate (DMAEMA) and nonionic di(ethylene glycol) methyl ether methacrylate (DEGMA) were synthesized via atom transfer radical polymerization (ATRP) and used for the delivery of plasmid DNA in gene therapy. All stars were able to form polyplexes with plasmid DNA. The structure and size of the polyplexes were precisely determined using light scattering and cryo-TEM microscopy. The hydrodynamic radius of a complex of DNA with star was dependent on the architecture of the star arms, the DEGMA content and the number of amino groups in the star compared to the number of phosphate groups of the nucleic acid (N/P ratio). The smallest polyplexes (Rh90°∼50 nm) with positive zeta potentials (∼15 mV) were formed of stars with N/P=6. The introduction of DEGMA into the star structure caused a decrease of polyplex cytotoxicity in comparison to DMAEMA homopolymer stars. The overall transfection efficiency using HT-1080 cells showed that the studied systems are prospective gene delivery agents. The most promising results were obtained for stars with random copolymer arms of high DEGMA content.

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

    PubMed

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

    2013-02-11

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

  12. 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.

  13. Alcea rosea root extract as a preventive and curative agent in ethylene glycol-induced urolithiasis in rats

    PubMed Central

    Ahmadi, Marzieh; Rad, Abolfazl Khajavi; Rajaei, Ziba; Hadjzadeh, Mousa-Al-Reza; Mohammadian, Nema; Tabasi, Nafiseh Sadat

    2012-01-01

    Introduction: Alcea rosea L. is used in Asian folk medicine as a remedy for a wide range of ailments. The aim of the present study was to investigate the effect of hydroalcoholic extract of Alcea rosea roots on ethylene glycol-induced kidney calculi in rats. Materials and Methods: Male Wistar rats were randomly divided into control, ethylene glycol (EG), curative and preventive groups. Control group received tap drinking water for 28 days. Ethylene glycol (EG), curative and preventive groups received 1% ethylene glycol for induction of calcium oxalate (CaOx) calculus formation; preventive and curative subjects also received the hydroalcoholic extract of Alcea rosea roots in drinking water at dose of 170 mg/kg, since day 0 or day 14, respectively. Urinary oxalate concentration was measured by spectrophotometer on days 0, 14 and 28. On day 28, the kidneys were removed and examined histopathologically under light microscopy for counting the calcium oxalate deposits in 50 microscopic fields. Results: In both preventive and curative protocols, treatment of rats with hydroalcoholic extract of Alcea rosea roots significantly reduced the number of kidney calcium oxalate deposits compared to ethylene glycol group. Administration of Alcea rosea extract also reduced the elevated urinary oxalate due to ethylene glycol. Conclusion: Alcea rosea showed a beneficial effect in preventing and eliminating calcium oxalate deposition in the rat kidney. This effect is possibly due to diuretic and anti-inflammatory effects or presence of mucilaginous polysaccharides in the plant. It may also be related to lowering of urinary concentration of stone-forming constituents. PMID:22701236

  14. Rapeseed oil monoester of ethylene glycol monomethyl ether as a new biodiesel.

    PubMed

    Dayong, Jiang; Xuanjun, Wang; Shuguang, Liu; Hejun, Guo

    2011-01-01

    A novel biodiesel named rapeseed oil monoester of ethylene glycol monomethyl ether is developed. This fuel has one more ester group than the traditional biodiesel. The fuel was synthesized and structurally identified through FT-IR and P(1P)H NMR analyses. Engine test results show that when a tested diesel engine is fueled with this biodiesel in place of 0# diesel fuel, engine-out smoke emissions can be decreased by 25.0%-75.0%, CO emissions can be reduced by 50.0%, and unburned HC emissions are lessened significantly. However, NOx emissions generally do not change noticeably. In the area of combustion performance, both engine in-cylinder pressure and its changing rate with crankshaft angle are increased to some extent. Rapeseed oil monoester of ethylene glycol monomethyl ether has a much higher cetane number and shorter ignition delay, leading to autoignition 1.1°CA earlier than diesel fuel during engine operation. Because of certain amount of oxygen contained in the new biodiesel, the engine thermal efficiency is improved 13.5%-20.4% when fueled with the biodiesel compared with diesel fuel.

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

    PubMed Central

    Nagasaki, Yukio

    2010-01-01

    A poly(ethylene glycol)-b-poly[2-(N,N-dimethylamino)ethyl methacrylate] block copolymer possessing a reactive acetal group at the end of the poly(ethylene glycol) (PEG) chain, that is, acetal-PEG-b-PAMA, was synthesized by a proprietary polymerization technique. Gold nanoparticles (GNPs) were prepared using the thus-synthesized acetal-PEG-b-PAMA block copolymer. The PEG-b-PAMA not only acted as a reducing agent of aurate ions but also attached to the nanoparticle surface. The GNPs obtained had controlled sizes and narrow size distributions. They also showed high dispersion stability owing to the presence of PEG tethering chains on the surface. The same strategy should also be applicable to the fabrication of semiconductor quantum dots and inorganic porous nanoparticles. The preparation of nanoparticles in situ, i.e. in the presence of acetal-PEG-b-PAMA, gave the most densely packed polymer layer on the nanoparticle surface; this was not observed when coating preformed nanoparticles. PEG/polyamine block copolymer was more functional on the metal surface than PEG/polyamine graft copolymer, as confirmed by angle-dependent x-ray photoelectron spectroscopy. We successfully solubilized the C60 fullerene into aqueous media using acetal-PEG-b-PAMA. A C60/acetal-PEG-b-PAMA complex with a size below 5 nm was obtained by dialysis. The preparation and characterization of these materials are described in this review. PMID:27877362

  16. Preparation of Humidity-Sensitive Poly(Ethylene Glycol) Inverse Opal Micropatterns Using Colloidal Lithography.

    PubMed

    Yu, Bing; Cong, Hailin; Yang, Zhen; Yang, Shujing; Wang, Yuezhong; Zhai, Feng; Wang, Yifan

    2017-09-05

    Humidity-sensitive poly(ethylene glycol) (PEG) inverse opals with micropatterns of 2 μm wide anti-swell-broken grooves were prepared using polystyrene (PS) colloidal crystals as templates and colloidal lithography. Monodisperse PS colloids were deposited in an ordered manner onto glass slides using a double-substrate vertical deposition method to form colloidal crystal templates. Poly(ethylene glycol) diacrylate (PEGDA) with photoinitiator was infiltrated into the interspaces of the colloidal crystals and photo-crosslinked by UV irradiation through a photomask. After removal the PS templates and unexposed PEGDA by tetrahydrofuran (THF), PEG hydrogel micropatterns with three-dimensional ordered porous structures were obtained. The band gaps of the PS colloidal crystals and corresponding PEG hydrogel inverse opals were measured by UV-VIS reflection spectrometer, calculated by Bragg law and simulated by Band SOLVE. The obtained PEG hydrogel inverse opal micropatterns can be used as sensors for humidity sensing due to absorption and desorption of moisture in the band gap structures. The sensor had a very reliable performance after repeated humidity sensing, and could be mass produced facilely with very low cost. The photopatterned anti-swell-broken grooves play an important role in the reliability of the sensors.

  17. 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.

  18. Comparison of methanol and ethylene glycol oxidation by alloy and Core-Shell platinum based catalysts

    NASA Astrophysics Data System (ADS)

    Kaplan, D.; Burstein, L.; Rosenberg, Yu.; Peled, E.

    2011-10-01

    Two Core-Shell, RuCore-PtShell and IrNiCore-PtRuShell, XC72-supported catalyst were synthesized in a two-step deposition process with NaBH4 as reducing agent. The structure and composition of the Core-Shell catalysts were determined by EDS, XPS and XRD. Electrochemical characterization was performed with the use of cyclic voltammetry. Methanol and ethylene glycol oxidation activities of the Core-Shell catalysts (in terms of surface and mass activities) were studied at 80 °C and compared to those of a commercial Pt-Ru alloy catalyst. The surface activity of the alloy based catalyst, in the case of methanol oxidation, was found to be superior as a result of optimized surface Pt:Ru composition. However, the mass activity of the PtRu/IrNi/XC72 was higher than that of the alloy based catalyst by ∼50%. Regarding ethylene glycol oxidation, while the surface activity of the alloy based catalyst was slightly higher than that of the Pt/Ru/XC72 catalyst, the latter showed ∼66% higher activities in terms of A g-1 of Pt. These results show the potential of Core-Shell catalysts for reducing the cost of catalysts for DMFC and DEGFC.

  19. Cell adhesion on poly(propylene fumarate-co-ethylene glycol) hydrogels.

    PubMed

    Tanahashi, Kazuhiro; Mikos, Antonios G

    2002-12-15

    We synthesized poly(propylene fumarate-co-ethylene glycol) block copolymers [P(PF-co-EG)] that were crosslinked to form hydrogels and investigated the effect of copolymer composition on cell adhesion to the hydrogels. These copolymers were water soluble when the molar ratio of ethylene glycol repeating unit to propylene fumarate repeating unit was higher than 4.4. The water content of swollen hydrogels increased from 29 to 63% and the water contact angle decreased from 38 to 21 degrees as the molar ratio increased from 0.6 to 4.4. No significant change in either property was observed for ratios higher than 4.4. In a cell adhesion assay under serum-free conditions, the number of adherent platelets and smooth muscle cells decreased from 21 to 2% and from 78 to 20% of the initial seeding density, respectively, as the molar ratio increased from 0.6 to 7.8. Adherent smooth muscle cells did not spread on the hydrogels of the compositions tested. Adherent platelets did not show any filopodia. These results suggest that the hydrophilicity of P(PF-co-EG) hydrogels is one of the factors affecting cell adhesion, and that copolymer modification may be required for enhancing cell adhesion for an application involving the copolymers as in situ crosslinkable cell carriers.

  20. 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.

  1. Melting point equations for the ternary system water/sodium chloride/ethylene glycol revisited.

    PubMed

    Benson, James D; Bagchi, Aniruddha; Han, Xu; Critser, John K; Woods, Erik J

    2010-12-01

    Partial phase diagrams are of considerable utility in the development of optimized cryobiological procedures. Recent theoretical predictions of the melting points of ternary solutions of interest to cryobiology have caused us to re-examine measurements that our group made for the ethylene-glycol-sodium chloride-water phase diagram. Here we revisit our previous experiments by measuring melting points at five ethylene-glycol to sodium chloride ratios (R values; R=5, 10, 15, 30, and 45) and five levels of concentration for each ratio. Melting points were averaged from three measurements and plotted as a function of total solute concentration for each R value studied. The new measurements differed from our original experimental values and agreed with predicted values from both theoretical models. Additionally, the data were fit to the polynomial described in our previous report and the resulting equation was obtained: T(m) = (38.3-2.145 x 10⁻¹ R)w + (81.19 - 2.909×10⁻¹ R)w², where w is the total solute mass fraction. This new equation provided good fits to the experimental data as well as published values and relates the determined polynomial constants to the R value of the corresponding isopleths of the three dimensional phase diagram, allowing the liquids curve for any R value to be obtained. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. A newly developed chemically crosslinked dextran-poly(ethylene glycol) hydrogel for cartilage tissue engineering.

    PubMed

    Jukes, Jojanneke M; van der Aa, Leonardus J; Hiemstra, Christine; van Veen, Theun; Dijkstra, Pieter J; Zhong, Zhiyuan; Feijen, Jan; van Blitterswijk, Clemens A; de Boer, Jan

    2010-02-01

    Cartilage tissue engineering, in which chondrogenic cells are combined with a scaffold, is a cell-based approach to regenerate damaged cartilage. Various scaffold materials have been investigated, among which are hydrogels. Previously, we have developed dextran-based hydrogels that form under physiological conditions via a Michael-type addition reaction. Hydrogels can be formed in situ by mixing a thiol-functionalized dextran with a tetra-acrylated star poly(ethylene glycol) solution. In this article we describe how the degradation time of dextran-poly(ethylene glycol) hydrogels can be varied from 3 to 7 weeks by changing the degree of substitution of thiol groups on dextran. The degradation times increased slightly after encapsulation of chondrocytes in the gels. The effect of the gelation reaction on cell viability and cartilage formation in the hydrogels was investigated. Chondrocytes or embryonic stem cells were mixed in the aqueous dextran solution, and we confirmed that the cells survived gelation. After a 3-week culturing period, chondrocytes and embryonic stem cell-derived embryoid bodies were still viable and both cell types produced cartilaginous tissue. Our data demonstrate the potential of dextran hydrogels for cartilage tissue engineering strategies.

  3. Self-assembled hydrogel nanoparticles composed of dextran and poly(ethylene glycol) macromer.

    PubMed

    Kim, I S; Jeong, Y I; Kim, S H

    2000-09-15

    Biodegradable hydrogel nanoparticles were prepared from glycidyl methacrylate dextran (GMD) and dimethacrylate poly(ethylene glycol) (DMP). GMD was synthesized by coupling of glycidyl methacrylate to dextran in the presence of 4-(N,N-dimethylamino)pyridine (DMAP) using dimethylsulfoxide (DMSO) as an aprotic solvent. DMP was synthesized from poly(ethylene glycol) (PEG) and methacryloyl chloride. GMD/DMP (abbreviated as DP) hydrogel was prepared by radical polymerization of GMD and DMP using ammonium peroxydisulfate (APS) as an initiator and UV curing. DP hydrogel nanoparticles were obtained by diafiltration method using DMSO solution. The GMD and DMP were characterized by fourier transform infrared spectroscopy. Fluorescence probe technique was used to investigate the self-assembly of DP in water using pyrene as a hydrophobic probe. The critical association concentration (CAC) was determined to be 5.6 x 10(-2) g/l. The shape of DP hydrogel nanoparticles was spherical when observed by transmission electron microscope (TEM). The size range of DP hydrogel nanoparticles was about 20 approximately 50 nm. The hydrodynamic size of DP hydrogel nanoparticles was measured by photon correlation spectroscopy (PCS) and gradually increased with time in PBS (0.1 M, pH 7.4). Drug release study was performed using clonazepam (CNZ) as a hydrophobic model drug. In vitro release rate of CNZ from the DP hydrogel nanoparticles was dependent on the existence of dextranase and the pH of the release medium.

  4. Preparation of monodisperse and size-controlled poly(ethylene glycol) hydrogel nanoparticles using liposome templates.

    PubMed

    An, Se Yong; Bui, Minh-Phuong Ngoc; Nam, Yun Jung; Han, Kwi Nam; Li, Cheng Ai; Choo, Jaebum; Lee, Eun Kyu; Katoh, Shigeo; Kumada, Yoichi; Seong, Gi Hun

    2009-03-01

    Liposomes were used as templates to prepare size-controlled and monodisperse poly(ethylene glycol) (PEG) hydrogel nanoparticles. The procedure for the preparation of PEG nanoparticles using liposomes consists of encapsulation of photopolymerizable PEG hydrogel solution into the cavity of the liposomes, extrusion through a membrane with a specific pore size, and photopolymerization of the contents inside the liposomes by UV irradiation. The size distributions of the prepared particles were 1.32+/-0.16 microm (12%), 450+/-62 nm (14%), and 94+/-12 nm (13%) after extrusion through membrane filters with pore sizes of 1 microm, 400 nm, and 100 nm, respectively. With this approach, it is also possible to modify the surface of the hydrogel nanoparticles with various functional groups in a one-step procedure. To functionalize the surface of a PEG nanoparticle, methoxy poly(ethylene glycol)-aldehyde was added as copolymer to the hydrogel-forming components and aldehyde-functionalized PEG nanoparticles could be obtained easily by UV-induced photopolymerization, following conjugation with poly-L-lysine-FITC through amine-aldehyde coupling. The prepared PEG particles showed strong fluorescence from FITC on the edge of the particles using confocal microscopy. The immobilization of biomaterials such as enzymes in hydrogel particles could be performed with loading beta-galactosidases during the hydration step for liposome preparation without additional procedures. The resorufin produced by applying resorufin beta-D-galactopyranoside as the substrate showed the fluorescence under the confocal microscopy.

  5. Facile preparation of silver nanoparticles homogeneously immobilized in hierarchically monolithic silica using ethylene glycol as reductant.

    PubMed

    Yu, Huan; Zhu, Yang; Yang, Hui; Nakanishi, Kazuki; Kanamori, Kazuyoshi; Guo, Xingzhong

    2014-09-07

    A facile and "green" method was proposed to introduce Ag nanoparticles (Ag NPs) into the hierarchically monolithic silica uniformly in the presence of (3-aminopropyl)-triethoxysilane (APTES) and ethylene glycol. APTES is used to modify the monolith by incorporating amino groups onto the surface of meso-macroporous skeletons, while ethylene glycol is employed as the productive reductant. Ag NPs are homogeneously immobilized in hierarchically monolithic silica after reduction and drying at 40 °C for different duration times, and the embedded amount of Ag NPs can reach 15.44 wt% when treated once. The embedment of Ag NPs increases with the repeat treatment and the APTES amount, without uncontrollable crystalline growth. The surface areas of Ag NPs embedded in silica monoliths after heat treatment at 300 and 400 °C are higher than those before heat treatment. The modification via APTES and the embedment of Ag NPs does not spoil the morphology of monolithic silica, while changing the pore structures of the monolith. A tentative formation process and a reduction mechanism are proposed for the modification, reduction and embedment. Ag NPs embedded in monolithic silica is promising for wide applications such as catalysis and separation.

  6. Acyclovir delivery matrices based on poly(ethylene glycol)/chitosan semi-interpenetrating networks.

    PubMed

    Diez-Sales, O; Dolz, M; Hernandez, M J; Casanovas, A; Herraez, M

    2007-06-01

    Chitosan matrix systems have been studied as potential vehicles for the prolonged release of acyclovir (ACV). The influence of chitosan concentration (from 0.83% to 1.67%) on viscoelastic properties of formulations with and without glyoxal was analyzed. For chitosan-poly(ethylene glycol) 400 formulations loss modulus (G'') are greater than storage modulus (G'). This corresponds to the characteristic behavior of nonstructured systems. When glyoxal was added to the chitosan-poly(ethylene glycol) 400 formulations, gelled matrix was obtained (i.e., G' is higher than G''), except for the lowest chitosan concentration. ACV release rates for the both types of systems, with and without glyoxal, were also determined. The ACV diffusion coefficient values from matrices are less than for the respective formulation without glyoxal and it was found to depend on the crosslink density within the matrices. Viscoelastic parameters, dynamic moduli (G', G''), and complex viscosity (eta*), were correlated with the ACV diffusion coefficients (D). The complex viscosity (eta*) could be used as a parameter of predictive value for the release rate of drugs.

  7. 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

  8. 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.

  9. Poly(N-vinylimidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids.

    PubMed

    Schemeth, Dieter; Noël, Jean-Christophe; Jakschitz, Thomas; Rainer, Matthias; Tessadri, Richard; Huck, Christian W; Bonn, Günther K

    2015-07-23

    In this study we report the novel polymeric resin poly(N-vinyl imidazole/ethylene glycol dimethacrylate) for the purification and isolation of phenolic acids. The monomer to crosslinker ratio and the porogen composition were optimized for isolating phenolic acids diluted in acetonitrile at normal phase chromatography conditions, first. Acetonitrile serves as polar, aprotic solvent, dissolving phenolic acids but not interrupting interactions with the stationary phase due to the approved Hansen solubility parameters. The optimized resin demonstrated high loading capacities and adsorption abilities particularly for phenolic acids in both, acetonitrile and aqueous solutions. The adsorption behavior of aqueous standards can be attributed to ion exchange effects due to electrostatic interactions between protonated imidazole residues and deprotonated phenolic acids. Furthermore, adsorption experiments and subsequent curve fittings provide information of maximum loading capacities of single standards according to the Langmuir adsorption model. Recovery studies of the optimized polymer in the normal-phase and ion-exchange mode illustrate the powerful isolation properties for phenolic acids and are comparable or even better than typical, commercially available solid phase extraction materials. In order to prove the applicability, a highly complex extract of rosemary leaves was purified by poly(N-vinyl imidazole/ethylene glycol dimethacrylate) and the isolated compounds were identified using UHPLC-qTOF-MS.

  10. Rapeseed Oil Monoester of Ethylene Glycol Monomethyl Ether as a New Biodiesel

    PubMed Central

    Dayong, Jiang; Xuanjun, Wang; Shuguang, Liu; Hejun, Guo

    2011-01-01

    A novel biodiesel named rapeseed oil monoester of ethylene glycol monomethyl ether is developed. This fuel has one more ester group than the traditional biodiesel. The fuel was synthesized and structurally identified through FT-IR and P1PH NMR analyses. Engine test results show that when a tested diesel engine is fueled with this biodiesel in place of 0# diesel fuel, engine-out smoke emissions can be decreased by 25.0%–75.0%, CO emissions can be reduced by 50.0%, and unburned HC emissions are lessened significantly. However, NOx emissions generally do not change noticeably. In the area of combustion performance, both engine in-cylinder pressure and its changing rate with crankshaft angle are increased to some extent. Rapeseed oil monoester of ethylene glycol monomethyl ether has a much higher cetane number and shorter ignition delay, leading to autoignition 1.1°CA earlier than diesel fuel during engine operation. Because of certain amount of oxygen contained in the new biodiesel, the engine thermal efficiency is improved 13.5%–20.4% when fueled with the biodiesel compared with diesel fuel. PMID:21403894

  11. Antiurolithiatic Effects of Solanum xanthocarpum Fruit Extract on Ethylene-Glycol-Induced Nephrolithiasis in Rats

    PubMed Central

    Patel, PK; Patel, MA; Saralai, MG; Gandhi, TR

    2012-01-01

    This study was designed to evaluate the effects of Solanum xanthocarpum fruit extract in ethylene-glycol-induced urolithiasis in the male Wistar rats. Nephrolithiasis was induced in male Wistar rats by adding ethylene glycol (0.75%) in drinking water for 28 days. Animals were divided into six groups, each containing six viz. Vehicle control, model control, S. xanthocarpum methanol extract in different doses of 100, 200, and 400 mg/kg p.o., Cystone (750 mg/kg, p.o.) served as a standard. Hyperoxaluria as well as an increase in the excretion of calcium, phosphate, uric acid and decrease in citrate and magnesium in urine, impairment of renal function and oxidative imbalance in kidney were observed in the calculi-induced group. Treatment with S. xanthocarpum decreases hyperoxaluria, calcium, and uric acid, improves renal function, and also produces antioxidant effects. Crystalluria was characterized by excretion calcium oxalate (CaOX) crystals, which were enormous in the lithogenic group but smaller in the drug-treated group. The histology showed that the calculi-induced group had a large deposition of CaOX crystals in kidney while the treated group had trivial and fewer deposits. The result indicates the antiurolithiatic activity of S. xanthocarpum mediated possibly by CaOX crystal inhibition, diuretic, antioxidant and maintaining balance between stone promoter and inhibitor constituents, and this study rationalized its medicinal use in urolithiasis. PMID:23112535

  12. N-Monosubstituted Methoxy-oligo(ethylene glycol) Carbamate Ester Prodrugs of Resveratrol.

    PubMed

    Mattarei, Andrea; Azzolini, Michele; Zoratti, Mario; Biasutto, Lucia; Paradisi, Cristina

    2015-09-03

    Resveratrol is a natural polyphenol with many interesting biological activities. Its pharmacological exploitation in vivo is, however, hindered by its rapid elimination via phase II conjugative metabolism at the intestinal and, most importantly, hepatic levels. One approach to bypass this problem relies on prodrugs. We report here the synthesis, characterization, hydrolysis, and in vivo pharmacokinetic behavior of resveratrol prodrugs in which the OH groups are engaged in an N-monosubstituted carbamate ester linkage. As promoiety, methoxy-oligo(ethylene glycol) groups (m-OEG) (CH₃-[OCH₂CH₂]n-) of defined chain length (n = 3, 4, 6) were used. These are expected to modulate the chemico-physical properties of the resulting derivatives, much like longer poly(ethylene glycol) (PEG) chains, while retaining a relatively low MW and, thus, a favorable drug loading capacity. Intragastric administration to rats resulted in the appearance in the bloodstream of the prodrug and of the products of its partial hydrolysis, confirming protection from first-pass metabolism during absorption.

  13. Hydrogen production through aqueous-phase reforming of ethylene glycol in a washcoated microchannel.

    PubMed

    D'Angelo, M Fernanda Neira; Ordomsky, Vitaly; Paunovic, Violeta; van der Schaaf, John; Schouten, Jaap C; Nijhuis, T Alexander

    2013-09-01

    Aqueous-phase reforming (APR) of biocarbohydrates is conducted in a catalytically stable washcoated microreactor where multiphase hydrogen removal enhances hydrogen efficiency. Single microchannel experiments are conducted following a simplified model based on the microreactor concept. A coating method to deposit a Pt-based catalyst on the microchannel walls is selected and optimized. APR reactivity tests are performed by using ethylene glycol as the model compound. Optimum results are achieved with a static washcoating technique; a highly uniform and well adhered 5 μm layer is deposited on the walls of a 320 μm internal diameter (ID) microchannel in one single step. During APR of ethylene glycol, the catalyst layer exhibits high stability over 10 days after limited initial deactivation. The microchannel presents higher conversion and selectivity to hydrogen than a fixed-bed reactor. The benefits of using a microreactor for APR can be further enhanced by utilizing increased Pt loadings, higher reaction temperatures, and larger carbohydrates (e.g., glucose). The use of microtechnology for aqueous-phase reforming will allow for a great reduction in the reformer size, thus rendering it promising for distributed hydrogen production. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Hydrogen production from steam reforming of ethylene glycol over iron loaded on MgO

    NASA Astrophysics Data System (ADS)

    Chen, Mingqiang; Wang, Yishuang; Liang, Tian; Yang, Jie; Yang, Zhonglian

    2017-01-01

    In this study, a series of Fe-based catalysts loaded on MgO were prepared by a precipitation technique. And they were tested in hydrogen production from steam reforming of ethylene glycol (SRE), which was a representative model compound of fast bio-oil. The catalysts were characterized by XRD, SEM and H2-TPR analysis. The results showed that the crystalline phases of catalysts contained Fe2O3 (Hematite), Fe3O4 (Magnetite), Fe2MgO4 (iron magnesium oxide) and MgO, and morphology of MgO was changed from the rugby-ball like particles to spherical particles with the addition of Fe. In addition, the catalytic test results indicated that the 18%Fe/MgO catalyst exhibited the highest ethylene glycol conversion (˜99.8%) and H2 molar percent (˜77%) during at the following conditions: H2O/C molar ratio is 5˜7, the feeding rate is 14 mL/h and the reaction temperature at 600˜650°C. Furthermore, the 18%Fe/MgO catalyst can keep outstanding stability during SRE for 12 h.

  15. Improving enzymatic hydrolysis of corn stover pretreated by ethylene glycol-perchloric acid-water mixture.

    PubMed

    He, Yu-Cai; Liu, Feng; Gong, Lei; Lu, Ting; Ding, Yun; Zhang, Dan-Ping; Qing, Qing; Zhang, Yue

    2015-02-01

    To improve the enzymatic saccharification of lignocellulosic biomass, a mixture of ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) was used for pretreating corn stover in this study. After the optimization in oil-bath system, the optimum pretreatment temperature and time were 130 °C and 30 min, respectively. After the saccharification of 10 g/L pretreated corn stover for 48 h, the saccharification rate was obtained in the yield of 77.4 %. To decrease pretreatment temperature and shorten pretreatment time, ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) media under microwave irradiation was employed to pretreat corn stover effectively at 100 °C and 200 W for 5 min. Finally, the recovered hydrolyzates containing glucose obtained from the enzymatic hydrolysis of pretreated corn stovers could be fermented into ethanol efficiently. These results would be helpful for developing a cost-effective pretreatment combined with enzymatic saccharification of cellulosic materials for the production of lignocellulosic ethanol.

  16. Alginate-Poly(ethylene glycol) Hybrid Microspheres for Primary Cell Microencapsulation.

    PubMed

    Mahou, Redouan; Meier, Raphael P H; Bühler, Léo H; Wandrey, Christine

    2014-01-09

    The progress of medical therapies, which rely on the transplantation of microencapsulated living cells, depends on the quality of the encapsulating material. Such material has to be biocompatible, and the microencapsulation process must be simple and not harm the cells. Alginate-poly(ethylene glycol) hybrid microspheres (alg-PEG-M) were produced by combining ionotropic gelation of sodium alginate (Na-alg) using calcium ions with covalent crosslinking of vinyl sulfone-terminated multi-arm poly(ethylene glycol) (PEG-VS). In a one-step microsphere formation process, fast ionotropic gelation yields spherical calcium alginate gel beads, which serve as a matrix for simultaneously but slowly occurring covalent cross-linking of the PEG-VS molecules. The feasibility of cell microencapsulation was studied using primary human foreskin fibroblasts (EDX cells) as a model. The use of cell culture media as polymer solvent, gelation bath, and storage medium did not negatively affect the alg-PEG-M properties. Microencapsulated EDX cells maintained their viability and proliferated. This study demonstrates the feasibility of primary cell microencapsulation within the novel microsphere type alg-PEG-M, serves as reference for future therapy development, and confirms the suitability of EDX cells as control model.

  17. Alginate-Poly(ethylene glycol) Hybrid Microspheres for Primary Cell Microencapsulation

    PubMed Central

    Mahou, Redouan; Meier, Raphael P. H.; Bühler, Léo H.; Wandrey, Christine

    2014-01-01

    The progress of medical therapies, which rely on the transplantation of microencapsulated living cells, depends on the quality of the encapsulating material. Such material has to be biocompatible, and the microencapsulation process must be simple and not harm the cells. Alginate-poly(ethylene glycol) hybrid microspheres (alg-PEG-M) were produced by combining ionotropic gelation of sodium alginate (Na-alg) using calcium ions with covalent crosslinking of vinyl sulfone-terminated multi-arm poly(ethylene glycol) (PEG-VS). In a one-step microsphere formation process, fast ionotropic gelation yields spherical calcium alginate gel beads, which serve as a matrix for simultaneously but slowly occurring covalent cross-linking of the PEG-VS molecules. The feasibility of cell microencapsulation was studied using primary human foreskin fibroblasts (EDX cells) as a model. The use of cell culture media as polymer solvent, gelation bath, and storage medium did not negatively affect the alg-PEG-M properties. Microencapsulated EDX cells maintained their viability and proliferated. This study demonstrates the feasibility of primary cell microencapsulation within the novel microsphere type alg-PEG-M, serves as reference for future therapy development, and confirms the suitability of EDX cells as control model. PMID:28788456

  18. Integrative design of a poly(ethylene glycol)-poly(propylene glycol)-alginate hydrogel to control three dimensional biomineralization.

    PubMed

    Cha, Chaenyung; Kim, Eun-Seok; Kim, Il Won; Kong, Hyunjoon

    2011-04-01

    A mineralized polymeric matrix has been extensively studied to understand biomineralization processes and to further regulate phenotypic functions of various cells involved in osteogenesis and physiological homeostasis. It has been often proposed that several matrix variables including charge density, hydrophobicity, and pore size play vital roles in modulating composition and morphology of minerals formed within a three dimensional (3D) matrix. However, the aspects have not yet been systematically examined because a tool enabling the independent control of the matrix variables is lacking. This study presents an advanced integrative strategy to control morphology and composition of biominerals with matrix properties, by using a hydrogel formulated to independently control charge density, hydrophobicity, and porosity. The hydrogel consists of poly(ethylene glycol) monomethacrylate (PEGmM), poly(propylene glycol) monomethacrylate (PPGmM), and methacrylic alginate (MA), so the charge density and hydrophobicity of the hydrogel can be separately controlled with mass fractions of MA and PPGmM. Also, hydrogels which present only nano-sized pores, termed nanoporous hydrogels, are lyophilized and rehydrated to prepare the hydrogels containing micro-sized pores, termed microporous hydrogels. We find that increasing the mass fractions of MA and PPGmM of the microporous hydrogel promotes the growth of apatite layers because of the increases in the charge density, hydrophobicity and pore size. In contrast, increasing mass fractions of MA and PPGmM of the nanoporous hydrogel enhances the formation of calcium carbonate minerals. The dependency of the mineralization on hydrogel variables is related to the change in supersaturation of mineral ions. Overall, the results of this study will be highly useful to better understand the interplay of matrix variables in biomineralization and to design a wide array of mineralized matrix potentially used in cell therapies and tissue

  19. Morphology and surface properties of blends of Eudragit RS with different poly(ethylene glycol)s.

    PubMed

    Lovrecich, M; Rubessa, F

    1998-02-01

    The purpose of this study was to investigate the morphology and surface properties of blends of Eudragit RS, a hydrophobic polymer mainly used for film coating, and poly(ethylene glycol)s (PEG), amphiphilic polymers used as softeners for films. Blends of Eudragit RS and PEGs were prepared as films using the casting technique from methylene chloride. The morphology of those films was evaluated by scanning electron microscopy before and after treatment with water. Sessile drop technique was used to measure solid/liquid contact angles in order to calculate surface free-energy parameters and to investigate phase separation using the Cassie-Baxter approach. Films containing 20, 40, 50, and 60% PEG 3400 and PEG 6000 appeared morphologically unchanged after treatment with water; no phase separation was noticed. Films containing PEG 14,000 after treatment with water showed the presence of a solid emulsion in the range 40, 50, and 60% PEG; a multiple solid emulsion was shown for films containing 60% PEG 20,000. The presence of two-phase systems was shown using contact angle measurements and results were in agreement with microscopic analysis. Calculated surface free-energy parameters indicated that PEG 3400 and 20,000 in a critical concentration of 10% can modify surface parameters of Eudragit RS: for PEG 6000 and 14,000 this critical concentration was found to be between 10 and 20%. The surface polarity of PEG 3400, 6000, and 14,000 was found to be drastically reduced upon addition of 5% Eudragit RS; spontaneous surface layering of Eudragit RS could be reasonably hypothesized for PEG 3400. This study revealed that surface parameters of a polymer can be modified in the presence of a relatively small amount of a second material.

  20. Influence of ethylene glycol and propylene glycol on polymer diffusion in poly(butyl acrylate-co-methyl methacrylate) latex films.

    PubMed

    Schroeder, Walter F; Liu, Yuanqin; Tomba, J Pablo; Soleimani, Mohsen; Lau, Willie; Winnik, Mitchell A

    2010-03-11

    We describe fluorescence resonance energy transfer (FRET) experiments carried out to examine the effect of ethylene glycol and propylene glycol on the early stages of polymer diffusion in poly(butyl acrylate-co-methyl methacrylate) latex films. In our approach, we temporarily arrest the drying process of a wet latex film by sealing the film in a previously cooled airtight sample chamber. This arrests propagation of the drying front and suppresses polymer diffusion during the measurements. We then measure donor fluorescence decays from 0.5 mm diameter spots at various locations on the film. From our analysis, we obtain information about the earliest stages of polymer diffusion as the film is still drying. We also investigate the effect of these glycols on polymer diffusion at longer aging times on predried latex films. Ethylene glycol and propylene glycol retard polymer diffusion at early times immediately after the passing of the drying front but enhance the rate of polymer diffusion at later aging times. This behavior is described quantitatively in terms of free-volume theory and the partitioning of the glycols between the aqueous and polymer phases in the film.

  1. Nano-structured Platinum-based Catalysts for the Complete Oxidation of Ethylene Glycol and Glycerol

    NASA Astrophysics Data System (ADS)

    Falase, Akinbayowa

    Direct alcohol fuel cells are a viable alternative to the traditional hydrogen PEM fuel cell. Fuel versatility, integration with existing distribution networks, and increased safety when handling these fuels increases their appeal for portable power applications. In order to maximize their utility, the liquid fuel must be fully oxidized to CO2 so as to harvest the full amount of energy. Methanol and ethanol are widely researched as potential fuels to power these devices, but methanol is a toxic substance, and ethanol has a much lower energy density than other liquids such as gasoline or glucose. Oxidation of complex fuels is difficult to realize, due to difficulty in breaking carbon-carbon bonding and poisoning of the catalysts by oxidative byproducts. In order to achieve the highest efficiency, an anode needs to be engineered in such a way as to maximize activity while minimizing poisoning effects of reaction byproducts. We have engineered an anode that uses platinum-based catalysts that is capable of completely oxidizing ethylene glycol and glycerol in neutral and alkaline media with little evidence of CO poisoning. We have constructed a hybrid anode consisting of a nano-structured PtRu electrocatayst with an NAD-dependent alcohol dehydrogenase for improved oxidation of complex molecules. A nano-structured PtRu catalyst was used to oxidize ethylene glycol and glycerol in neutral media. In situ infrared spectroscopy was used to verify complete oxidation via CO2 generation. There was no evidence of poisoning by CO species. A pH study was performed to determine the effect of pH on oxidative current. The peak currents did not trend at 60 mV/pH unit as would be expected from the Nernst equation, suggesting that adsorption of fuel to the surface of the electrode is not an electron-transfer step. We synthesized nano-structured PtRu, PtSn, and PtRuSn catalysts for oxidation of ethylene glycol and glycerol in alkaline media. The PtRu electrocatalyst the highest oxidative

  2. Synthesis and characterization of novel biotinylated biodegradable poly(ethylene glycol)-b-poly(carbonate-lactic acid) copolymers.

    PubMed

    Xie, Zhigang; Guan, Huili; Lü, Changhai; Chen, Xuesi; Jing, Xiabin

    2005-11-01

    Poly(ethylene glycol)-b-poly(5-benzyloxy-trimethylene carbonate-lactic acid) copolymers (PEG-b-P(BTMC-LA)) were synthesized by ring-opening polymerization of lactide and 5-benzyloxy trimethylene carbonate in the presence of mono-hydroxyl poly(ethylene glycol) with diethyl zinc as catalyst. They were further converted into deprotected copolymers with the pendant hydroxyl groups by hydrogenolysis in the presence of Pd(OH)2/C, and finally conjugated with biotin through the free hydroxyl groups. Gel permeation chromatography, Fourier transform infrared, differential scanning calorimetry and 1H nuclear magnetic resonance studies confirmed the copolymer structures and successful attachment of biotin to the copolymer.

  3. Synthesis and characterization of poly(D,L-lactide)-poly(ethylene glycol) multiblock poly(ether-ester-urethane)s

    NASA Astrophysics Data System (ADS)

    Haw, Tan Ching; Ahmad, Azizan; Anuar, Farah Hannan

    2015-09-01

    In this study, poly(D,L-lactide)-poly(ethylene glycol) multiblock poly(ether-ester-urethane)s was synthesized in the framework of environmental friendly products to meet the need for highly flexible polymers. Triblock copolymer with poly(ethylene glycol) as center block and poly(D,L-lactide) as side block were first synthesized by ring-opening polymerization of D,L-lactide, followed by chain extension reaction of triblocks using hexamethylene diisocyanate (HMDI). NMR and infra-red spectroscopies were used to determine the molecular composition whereas XRD analysis revealed crystallinity behavior of synthesized multiblock copolymers.

  4. Testicular toxicity produced by ethylene glycol monomethyl and monoethyl ethers in the rat.

    PubMed Central

    Foster, P M; Creasy, D M; Foster, J R; Gray, T J

    1984-01-01

    Ethylene glycol monomethyl ether (EGME) and ethylene glycol monoethyl ether (EGEE) were administered orally to young male rats at doses varying from 50 to 500 mg/kg/day and 250 to 1000 mg/kg/day for EGME and EGEE, respectively, for 11 days. At sequential times animals were killed and testicular histology examined. The initial and major site of damage following EGME treatment was restricted to the primary spermatocytes undergoing postzygotene meiotic maturation and division. EGEE produced damage of an identical nature, but a larger dose was required to elicit equivalent severity (500 mg EGEE/kg being approximately equivalent to 100 mg EGME/kg). Additionally, within the spermatocyte population, differential sensitivity was observed depending on the precise stage of meiotic maturation: dividing (stage XIV) and early pachytene (stages I-II) greater than late pachytene (stages VIII-XIII) greater than mid-pachytene (stages III-VII). Equivalent doses of methoxyacetic acid (MAA) and ethoxyacetic acid (EAA) gave injury similar to the corresponding glycol ether. When animals were pretreated with inhibitors of alcohol metabolism followed by a testicular toxic dose of EGME (500 mg/kg), an inhibitor of alcohol dehydrogenase (pyrazole) offered complete protection. Pretreatment with the aldehyde dehydrogenase inhibitors disulfiram or pargyline did not ameliorate the testicular toxicity of EGME. In mixed cultures of Sertoli-germ cells, MAA and not EGME produced effects on spermatocytes analogous to that seen in vivo, at concentrations approximately equivalent to steady-state plasma levels after a single oral dose of EGME (500 mg/kg). It would seem likely that a metabolite (MAA or possibly methoxyacetaldehyde) and not EGME is responsible for the production of testicular damage. Images FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 9. (a) FIGURE 9. (b) PMID:6499806

  5. Atmospheric chemistry of toxic contaminants 2. Saturated aliphatics: Acetaldehyde, dioxane, ethylene glycol ethers, propylene oxide

    SciTech Connect

    Grosjean, D. )

    1990-11-01

    Detailed mechanisms are outlined for the chemical reactions that contribute to in-situ formation and atmospheric removal of the saturated aliphatic contaminants acetaldehyde, dioxane, ethylene glycol ethers (methyl, ethyl, n-butyl) and propylene oxide. In-situ formation is of major importance for acetaldehyde. In-situ removal involves reaction with OH (all compounds) and, for acetaldehyde, photolysis and reaction with NO{sub 3}. Acetaldehyde, dioxane, and the ethers are rapidly removed (half-lives of less than one day), leading to PAN (acetaldehyde) and to 2-oxodioxane and formaldehyde (dioxane). Reaction products of the glycol ethers include a large number of hydroxyesters, hydroxyacids, and hydroxycarbonyls. Propylene oxide reacts only slowly with OH, with an atmospheric half-life of 3 - 10 days, to yeild formaldehyde, acetaldehyde, and PAN. Uncertainties in the reaction mechanisms for dioxane, the glycol ethers, and propylene oxide are discussed and include C-C vs C-O bond scission in alkoxy radicals as well as alkoxy radical unimolecular decomposition vs reaction with oxygen.

  6. Cellulose nanocrystal-poly(oligo(ethylene glycol) methacrylate) brushes with tunable LCSTs.

    PubMed

    Grishkewich, Nathan; Akhlaghi, Seyedeh Parinaz; Zhaoling, Yao; Berry, Richard; Tam, Kam C

    2016-06-25

    This paper reports on the synthesis of poly(oligoethylene glycol) methyl ether acrylate (POEGMA) grafted cellulose nanocrystals (CNCs) via surface initiated atom transfer radical polymerization (ATRP). An ATRP initiator (α-Bromoisobutyryl bromide) was covalently bonded to the surface of CNCs, followed by copolymerizing di(ethylene glycol) methyl ether methacrylate (MEO2MA) and oligoethylene glycol methyl ether methacrylate (OEGMA300) monomers from the surface using Cu(I)Br/2,2-dipyridal. Multiple POEGMA-g-CNC systems with varying MEO2MA/OEGMA300 content were synthesized, and they displayed a range of lower critical solution temperatures (LCSTs) in aqueous medium. μDSC endotherms and microstructural analysis indicated the collapse of POEGMA chains, followed by the aggregation of nanoparticles above their LCSTs. Cloud point measurements demonstrated a hysteresis in the heating and cooling of the POEGMA-g-CNC systems. It was found that the LCST of the nanoparticles could be tuned to between 23.8 to 63.8°C by adjusting the OEGMA300 content of the POEGMA brushes.

  7. Membranes of Polymers of Intrinsic Microporosity (PIM-1) Modified by Poly(ethylene glycol)

    PubMed Central

    Bengtson, Gisela; Neumann, Silvio; Filiz, Volkan

    2017-01-01

    Until now, the leading polymer of intrinsic microporosity PIM-1 has become quite famous for its high membrane permeability for many gases in gas separation, linked, however, to a rather moderate selectivity. The combination with the hydrophilic and low permeable poly(ethylene glycol) (PEG) and poly(ethylene oxides) (PEO) should on the one hand reduce permeability, while on the other hand enhance selectivity, especially for the polar gas CO2 by improving the hydrophilicity of the membranes. Four different paths to combine PIM-1 with PEG or poly(ethylene oxide) and poly(propylene oxide) (PPO) were studied: physically blending, quenching of polycondensation, synthesis of multiblock copolymers and synthesis of copolymers with PEO/PPO side chain. Blends and new, chemically linked polymers were successfully formed into free standing dense membranes and measured in single gas permeation of N2, O2, CO2 and CH4 by time lag method. As expected, permeability was lowered by any substantial addition of PEG/PEO/PPO regardless the manufacturing process and proportionally to the added amount. About 6 to 7 wt % of PEG/PEO/PPO added to PIM-1 halved permeability compared to PIM-1 membrane prepared under similar conditions. Consequently, selectivity from single gas measurements increased up to values of about 30 for CO2/N2 gas pair, a maximum of 18 for CO2/CH4 and 3.5 for O2/N2. PMID:28587247

  8. Dehydration and Dehydrogenation of Ethylene Glycol on Rutile TiO2(110)

    SciTech Connect

    Li, Zhenjun; Kay, Bruce D.; Dohnalek, Zdenek

    2013-08-07

    The interactions of ethylene glycol (EG) with partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on the surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one EG per two Ti sites. Most of the adsorbed ethanol (~80%) undergoes further reactions to other products. Two major channels are observed, dehydration yielding ethylene and water and dehydrogenation yielding acetaldehyde and hydrogen. Hydrogen formation is rather surprising as it has not been observed previously on TiO2(110) from simple organic molecules. The coverage dependent yields of ethylene and acetaldehyde correlate well with that of water and hydrogen, respectively. Dehydration dominates at lower EG coverages (< 0.2 ML) and plateaus as the coverage is increased to saturation. Dehydrogenation is observed primarily at higher EG coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.

  9. Application of poly(ethylene glycol)-b-poly(epsilon-caprolactone) copolymers with different Poly(ethylene glycol) contents for the preparation of PEG-coated nanoparticles.

    PubMed

    Hou, Jingwen; Qian, Changyun; Zhang, Yanting; Guo, Shengrong

    2013-02-01

    This work used one poly(ethylene glycol)-b-poly(epsilon-caprolactone) (PEG-b-PCL) copolymer with low PEG content as matrix material and the copolymers with high PEG content as emulsifier to prepare PEG-coated nanoparticles for controlled release of paclitaxel by solvent evaporation technique. The copolymers were synthesized by ring-opening polymerization and characterized by 1H NMR and gel permeation chromatography (GPC). The effects of the composition and concentration of the copolymers used as emulsifier on the diameters and encapsulation efficiency of nanoparticles were investigated. The mean hydrodynamic diameters of the nanoparticles measured by dynamic light scattering ranged from 70 to 160 nm. The higher PEG content of emulsifier led to bigger diameter of nanoparticles and the emulsifier concentration (0.1%-1.0%) had no obvious influence on the diameters. The paclitaxel-loaded nanoparticles could achieve a sustained drug release for 7 days. When 2%-30% (w/v) of inulin was used as cryoprotectant during freeze drying process, the lyophilized nanoparticles could be well reconstituted into aqueous solution and the hydrodynamic diameter was not obviously changed.

  10. Poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers: preparation and aqueous solution properties.

    PubMed

    Horgan, Adrian; Saunders, Brian; Vincent, Brian; Heenan, Richard K

    2003-06-15

    A series of water-soluble, amphiphilic graft copolymers has been prepared by free-radical copolymerization of methoxypoly(ethylene glycol) macromonomers, with either methyl methacrylate or butyl methacrylate as the comonomers, in water/ethanol solvent mixtures. Lower molecular weight copolymers were obtained by increasing the concentration of the initiator, azobisisobutyronitrile (AIBN), used in the polymerization reaction. However, the route used also led to the formation of significant quantities of tetramethylsuccinodinitrile, a toxic byproduct resulting from the cage reaction of AIBN. Static fluorescence measurements using pyrene as a probe, along with 1H NMR experiments, showed that the graft copolymers form aggregates in water at very low concentrations (approximately 0.01 g l(-1)) with the pendant hydrophilic graft chains forming a stabilizing shell around the hydrophobic backbone. An increase in the hydrophile-lipophile balance of the graft copolymers was found to lead to smaller aggregates with lower aggregation numbers and highly swollen hydrophilic shells, as revealed by small angle neutron scattering (SANS).

  11. Preparation and in vitro characterization of dexamethasone-loaded poly(D,L-lactic acid) microspheres embedded in poly(ethylene glycol)-poly({varepsilon}-caprolactone)-poly(ethylene glycol) hydrogel for orthopedic tissue engineering.

    PubMed

    Fan, Min; Guo, QingFa; Luo, JingCong; Luo, Feng; Xie, Ping; Tang, XiaoHai; Qian, ZhiYong

    2013-08-01

    The corium is decreased to about half of its thickness in skin defects and wrinkles due to gravity and environment. In this study, dexamethasone/poly(d,l-lactic acid) (Mn = 160,000) microspheres were incorporated into poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (Mn = 3300) hydrogel to prepare an injectable hydrogel composite. The composite was designed to increase the thickness of the corium. Dexamethasone/poly(d,l-lactic acid) microspheres were prepared by oil-in-water emulsion/solvent evaporation technique. The properties of microspheres were investigated by size distribution measurement, scanning electron microscope and x-ray diffraction. Drug loading, encapsulation efficiency, and drug delivery behavior of microspheres were also studied in detail. Cell adhesion of microspheres was investigated by NIH3T3 cell in vitro. The properties of hydrogel composite were investigated by scanning electron microscope, rheological measurements and methyl thiazolyl tetrazolium assay. Drug release from composite was determined by HPLC-UV analysis. These results suggested that poly(d,l-lactic acid) microspheres encapsulating dexamethasone embedded in poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) hydrogel might have prospective application in orthopedic tissue engineering field.

  12. Proposed occupational exposure limits for select ethylene glycol ethers using PBPK models and Monte Carlo simulations.

    PubMed

    Sweeney, L M; Tyler, T R; Kirman, C R; Corley, R A; Reitz, R H; Paustenbach, D J; Holson, J F; Whorton, M D; Thompson, K M; Gargas, M L

    2001-07-01

    Methoxyethanol (ethylene glycol monomethyl ether, EGME), ethoxyethanol (ethylene glycol monoethyl ether, EGEE), and ethoxyethyl acetate (ethylene glycol monoethyl ether acetate, EGEEA) are all developmental toxicants in laboratory animals. Due to the imprecise nature of the exposure data in epidemiology studies of these chemicals, we relied on human and animal pharmacokinetic data, as well as animal toxicity data, to derive 3 occupational exposure limits (OELs). Physiologically based pharmacokinetic (PBPK) models for EGME, EGEE, and EGEEA in pregnant rats and humans have been developed (M. L. Gargas et al., 2000, Toxicol. Appl. Pharmacol. 165, 53-62; M. L. Gargas et al., 2000, Toxicol. Appl. Pharmacol. 165, 63-73). These models were used to calculate estimated human-equivalent no adverse effect levels (NAELs), based upon internal concentrations in rats exposed to no observed effect levels (NOELs) for developmental toxicity. Estimated NAEL values of 25 ppm for EGEEA and EGEE and 12 ppm for EGME were derived using average values for physiological, thermodynamic, and metabolic parameters in the PBPK model. The uncertainties in the point estimates for the NOELs and NAELs were estimated from the distribution of internal dose estimates obtained by varying key parameter values over expected ranges and probability distributions. Key parameters were identified through sensitivity analysis. Distributions of the values of these parameters were sampled using Monte Carlo techniques and appropriate dose metrics calculated for 1600 parameter sets. The 95th percentile values were used to calculate interindividual pharmacokinetic uncertainty factors (UFs) to account for variability among humans (UF(h,pk)). These values of 1.8 for EGEEA/EGEE and 1.7 for EGME are less than the default value of 3 for this area of uncertainty. The estimated human equivalent NAELs were divided by UF(h,pk) and the default UFs for pharmacodynamic variability among animals and among humans to calculate the

  13. Si-C linked oligo(ethylene glycol) layers in silicon-based photonic crystals: optimization for implantable optical materials.

    PubMed

    Kilian, Kristopher A; Böcking, Till; Gaus, Katharina; Gal, Michael; Gooding, J Justin

    2007-07-01

    Porous silicon has shown potential for various applications in biology and medicine, which require that the material (1) remain stable for the length of the intended application and (2) resist non-specific adsorption of proteins. Here we explore the efficacy of short oligo(ethylene glycol) moieties incorporated into organic layers via two separate strategies in achieving these aims. In the first strategy the porous silicon structure was modified in a single step via hydrosilylation of alpha-oligo(ethylene glycol)-omega-alkenes containing three or six ethylene glycol units. The second strategy employs two steps: (1) hydrosilylation of succinimidyl-10-undecenoate and (2) coupling of an amino hexa(ethylene glycol) species. The porous silicon photonic crystals modified by the two-step strategy displayed greater stability relative to the single step procedure when exposed to conditions of physiological temperature and pH. Both strategies produced layers that resist non-specific adsorption of proteins as determined with fluorescently labelled bovine serum albumin. The antifouling behaviour and greater stability to physiological conditions provided by this chemistry enhances the suitability of porous silicon for biomaterials applications.

  14. MICROWAVE-ASSISTED SHAPE CONTROLLED BULK SYNTHESIS OF AG AND FE NANORODS IN POLY (ETHYLENE GLYCOL) SOLUTIONS

    EPA Science Inventory

    Bulk syntheses of silver (Ag) and iron (Fe) nanorods using poly (ethylene glycol), PEG, under microwave irradiation (MW) conditions are reported. Favorable conditions to make Ag nanorods were established and can be extended to make Fe nanorods with uniform size and shape. The nan...

  15. Comparing ethylene glycol with glycerol for cryopreservation of buffalo bull semen in egg-yolk containing extenders.

    PubMed

    Swelum, A A; Mansour, H A; Elsayed, A A; Amer, H A

    2011-09-15

    The objective of this work was to evaluate the possibility of substituting glycerol for ethylene glycol when cryopreserving buffalo semen. Semen of eight buffalo bulls was mixed, pooled, and frozen in one of these four diluents: centrifuged Tris egg yolk glycerol; centrifuged Tris egg yolk ethylene glycol; centrifuged Milk egg yolk glycerol; or centrifuged Milk egg yolk ethylene glycol. Semen quality parameters assessed after thawing were motility, survivability, livability, sperm abnormality, acrosome integrity, and plasma membrane integrity. Conception rate and pregnancy rate were calculated after insemination of 104 buffaloes by straws of different groups (26 female/extender). Improvement in livability, sperm abnormality, acrosome integrity, plasma membrane integrity, conception rate, and pregnancy rate were seen when using ethylene glycol to replace glycerol when freezing buffalo bull semen in centrifuged TRIS egg yolk 61.15 ± 0.73, 24.85 ± 0.41, 69.10 ± 0.81, 71.75 ± 0.72, 46.2%, and 46.2%, respectively, followed by centrifuged milk egg yolk extenders. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. AuPd/polyaniline as the anode in an ethylene glycol microfluidic fuel cell operated at room temperature.

    PubMed

    Arjona, N; Palacios, A; Moreno-Zuria, A; Guerra-Balcázar, M; Ledesma-García, J; Arriaga, L G

    2014-08-04

    AuPd/polyaniline was used for the first time, for ethylene glycol (EG) electrooxidation in a novel microfluidic fuel cell (MFC) operated at room temperature. The device exhibits high electrocatalytic performance and stability for the conversion of cheap and fully available EG as fuel.

  17. Luminescent oligo(ethylene glycol)-functionalized cyclometalated platinum(II) complexes: cellular characterization and mitochondria-specific localization.

    PubMed

    Guo, Zhengqing; Tong, Wah-Leung; Chan, Michael C W

    2014-02-18

    A readily tunable series of non-planar oligo(ethylene glycol)-substituted phosphorescent Pt(II) complexes has been investigated as live cell imaging agents; suitable structural modifications can give good cellular uptake, traceable mitochondria-specific localization and potent cytotoxic characteristics towards HeLa cells.

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

    NASA Astrophysics Data System (ADS)

    Paulo, Maria Joao; de Matos, Bruno Ribeiro; Ntais, Spyridon; Fonseca, Fabio Coral; Tavares, Ana C.

    2013-02-01

    Mg-Al hydrotalcite-like compounds with OH- ions intercalated in the gallery and modified with monobutylether ethylene glycol ( mbeeg) were prepared from Mg6Al2(CO3)(OH)16·4H2O by the reconstruction method. The effect of the ethylene glycol, a moderate surfactant, on the textural properties and on the vapor water sorption of the layered double hydroxides was investigated by transmission electron microscopy and nitrogen and water sorption techniques. The ion conductivity of the samples was measured at 98 % RH up to 180 °C. The compounds are formed by nanoplatelets with a lateral size inferior to 20 nm. The addition of the ethylene glycol was found to increase the specific surface area, total pore volume, and water sorption capacity of the Mg-Al layered double hydroxide. However, it also decreased the average pore diameter, and the ion conductivity of the ethylene glycol modified layered double hydroxide was lower than expected based on the samples' specific surface area and water content.

  19. MICROWAVE-ASSISTED SHAPE CONTROLLED BULK SYNTHESIS OF AG AND FE NANORODS IN POLY (ETHYLENE GLYCOL) SOLUTIONS

    EPA Science Inventory

    Bulk syntheses of silver (Ag) and iron (Fe) nanorods using poly (ethylene glycol), PEG, under microwave irradiation (MW) conditions are reported. Favorable conditions to make Ag nanorods were established and can be extended to make Fe nanorods with uniform size and shape. The nan...

  20. Separation of parent homopolymers from polystyrene and poly(ethylene oxide) based block copolymers by liquid chromatography under limiting conditions of desorption-3. Study of barrier efficiency according to block copolymers' chemical composition.

    PubMed

    Rollet, Marion; Pelletier, Bérengère; Berek, Dušan; Maria, Sébastien; Phan, Trang N T; Gigmes, Didier

    2016-09-02

    Liquid Chromatography under Limiting Conditions of Desorption (LC LCD) is a powerful separation tool for multicomponent polymer systems. This technique is based on a barrier effect of an appropriate solvent, which is injected in front of the sample, and which decelerates the elution of selected macromolecules. In this study, the barrier effects have been evaluated for triblock copolymers polystyrene-b-poly(ethylene oxide)-b-polystyrene (PS-b-PEO-b-PS) according to the content of polystyrene (wt% PS) and PEO-block molar mass. PS-b-PEO-b-PS samples were prepared by Atom Transfer Radical Polymerization (ATRP). The presence of respective parent homopolymers was investigated by applying optimized LC LCD conditions. It was found that the barrier composition largely affects the efficiency of separation and it ought to be adjusted for particular composition range of block copolymers.

  1. Physical properties at the base for the development of an all-atom force field for ethylene glycol.

    PubMed

    Szefczyk, Borys; Cordeiro, M Natália D S

    2011-03-31

    Ethylene glycol, the simplest of the diols, is a popular solvent, an antifreeze agent, a coolant, and a precursor in polymer production. In molecular modeling it is a model compound used to develop potentials for complex systems, like sugars. Despite the fact that many force fields for ethylene glycol exist in the literature, only few of them have been designed to reproduce the macroscopic properties of glycol and its mixtures, and rather more attention has been paid to the microscopic structure of the liquid. Those potentials that reproduce the properties accurately, apply also nonstandard fudge factors, therefore are not fully compatible with any popular force field. In this paper, we present a new potential for ethylene glycol, based on the OPLS all-atom force field and fully compatible with it, as well as with popular models for water. This potential is carefully validated against a broad range of physical properties measured experimentally and published in the literature. These properties include the density, expansion coefficient, compressibility, enthalpy of vaporization, surface tension, self-diffusion coefficient, and viscosity. Therefore, the potential presented here may be used in simulations of not only pure glycol but also mixtures with water, organic solvents, ionic liquids, phase interfaces, etc.

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

    PubMed Central

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

    2016-01-01

    Microfluidic chip electrophoresis (MCE) is a powerful separation tool for biomacromolecule analysis. However, adsorption of biomacromolecules, particularly proteins onto microfluidic channels severely degrades the separation performance of MCE. In this paper, an anti-protein-fouling MCE was fabricated using a novel sandwich photolithography of poly(ethylene glycol) (PEG) prepolymers. Photopatterned microchannel with a minimum resolution of 10 μm was achieved. After equipped with a conventional online electrochemical detector, the device enabled baseline separation of bovine serum albumin, lysozyme (Lys), and cytochrome c (Cyt-c) in 53 s under a voltage of 200 V. Compared with a traditional polydimethylsiloxane MCE made by soft lithography, the PEG MCE made by the sandwich photolithography not only eliminated the need of a master mold and the additional modification process of the microchannel but also showed excellent anti-protein-fouling properties for protein separation. PMID:27493702

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

    PubMed

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

    2016-07-01

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

  4. Temperature, Molecular Weight, and Concentration Dependences of Thermal Diffusion for Ethylene Glycol Oligomers and Crown Ethers

    NASA Astrophysics Data System (ADS)

    Maeda, Kousaku; Kita, Rio; Shinyashiki, Naoki; Yagihara, Shin

    The Soret coefficient ST of ethylene glycol oligomers (EGOs) and crown ethers (CEs) in water were obtained by thermal diffusion forced Rayleigh scattering by changing the temperature, molecular weight, and concentration. The effect of a hydroxyl group on the EGOs and the effect of the cyclic structure of CEs on the thermal diffusion were determined systematically by changing the molecular weights of the EGOs and CEs. For dilute aqueous solutions, EGOs and CEs, except EG, show positive ST values that decrease with increasing temperature, which is similar to the results of previous studies on mixtures of water and organic solvents. The temperature dependence of ST changes its behavior from negative to positive with decreasing number of repeating units of EGOs. This behavior is related to the increase in the number density of the hydroxyl group. The ST values of EG show two different concentration regions, namely, the low concentration (0-2 wt %) and high concentration (2-100 wt %) regions.

  5. Poly(ethylene glycol)-salt aqueous two-phase systems with easily recyclable volatile salts.

    PubMed

    van Berlo, M; Luyben, K C; van der Wielen, L A

    1998-06-26

    Aqueous two-phase systems (ATPSs) have great potential in the downstream processing of fermentation products. However, the consumption of large amounts of auxiliary materials limits application in industrial practice. Promising alternatives to the salts used so far are volatile salts such as ammonium bicarbonate and ammonium carbamate, which can be recycled to the extraction system as gaseous carbon dioxide and ammonia. In this work, it is demonstrated that ammonium carbamate in combination with poly(ethylene glycol) (PEG, molecular masses of 2000, 4000 and 10000) indeed produces aqueous two-phase systems (ATPSs) at a temperature of 25 degrees C and atmospheric pressure. Ammonium bicarbonate is clearly not suitable as a phase-forming salt, because of its too-low solubility in water.

  6. Rheological and volumetric properties of TiO2-ethylene glycol nanofluids

    PubMed Central

    2013-01-01

    Homogeneous stable suspensions obtained by dispersing dry TiO2 nanoparticles in pure ethylene glycol were prepared and studied. Two types of nanocrystalline structure were analyzed, namely anatase and rutile phases, which have been characterized by scanning electron microscopy. The rheological behavior was determined for both nanofluids at nanoparticle mass concentrations up to 25%, including flow curves and frequency-dependent storage and loss moduli, using a cone-plate rotational rheometer. The effect of temperature over these flow curve tests at the highest concentration was also analyzed from 283.15 to 323.15 K. Furthermore, the influence of temperature, pressure, nanocrystalline structure, and concentration on the volumetric properties, including densities and isobaric thermal expansivities, were also analyzed. PMID:23763850

  7. 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

  8. 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.

  9. Broadband Dielectric Study on Dynamics of Poly(vinyl pyrrolidone)-Poly(ethylene glycol) Blend

    NASA Astrophysics Data System (ADS)

    Tsubotani, S.; Sudo, S.; Nakamura, H.; Shinyashiki, N.; Yagihara, S.; Sengwa, R. J.

    2004-04-01

    Dielectric measurements for blends of poly(vinyl pyrrolidone) (PVP) (Mw=40,000) and poly(ethylene glycol) (PEG) (Mw=400) with various compositions were carried out in the frequency range of 1μHz to 10GHz and temperatures range between 298 and 173K. Three relaxation processes were observed above 298K. The high frequency process (h1 process) is caused by the chain motion of PEG, the middle frequency process (m process) is caused by the segmental motion of PVP chains, and the low frequency process is caused by ionic impurities in the mixture. The relaxation time of h1 process increased with decreasing temperature and separated into two processes at 253K. Moreover h1 process was separated again at 223K. The relaxation time of h1 process was 100s at 208K. The glass transition is attributed to the motion of unfrozen PEG molecules.

  10. Rheological non-Newtonian behaviour of ethylene glycol-based Fe2O3 nanofluids

    PubMed Central

    2011-01-01

    The rheological behaviour of ethylene glycol-based nanofluids containing hexagonal scalenohedral-shaped α-Fe2O3 (hematite) nanoparticles at 303.15 K and particle weight concentrations up to 25% has been carried out using a cone-plate Physica MCR rheometer. The tests performed show that the studied nanofluids present non-Newtonian shear-thinning behaviour. In addition, the viscosity at a given shear rate is time dependent, i.e. the fluid is thixotropic. Finally, using strain sweep and frequency sweep tests, the storage modulus G', loss modulus G″ and damping factor were determined as a function of the frequency showing viscoelastic behaviour for all samples. PMID:22027018

  11. Engineering a novel biosynthetic pathway in Escherichia coli for production of renewable ethylene glycol.

    PubMed

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

    2016-02-01

    Ethylene glycol (EG) is an important commodity chemical with broad industrial applications. It is presently produced from petroleum or natural gas feedstocks in processes requiring consumption of significant quantities of non-renewable resources. Here, we report a novel pathway for biosynthesis of EG from the renewable sugar glucose in metabolically engineered Escherichia coli. Serine-to-EG conversion was first achieved through a pathway comprising serine decarboxylase, ethanolamine oxidase, and glycolaldehyde reductase. Serine provision in E. coli was then enhanced by overexpression of the serine-biosynthesis pathway. The integration of these two parts into the complete EG-biosynthesis pathway in E. coli allowed for production of 4.1 g/L EG at a cumulative yield of 0.14 g-EG/g-glucose, establishing a foundation for a promising biotechnology. © 2015 Wiley Periodicals, Inc.

  12. The effects of ethylene glycol and dimethyl sulfoxide on cerebroside metastability.

    PubMed

    Curatolo, W

    1985-07-11

    Aqueous dispersions of n-acyl cerebrosides are known to exhibit metastable polymorphism of the type: (Formula: see text). The involvement of hydration in this metastable polymorphism has been investigated by differential scanning calorimetric studies of aqueous palmitoylgalactocerebroside (C16:0-CER) dispersions in the presence of agents which disrupt water structure. In the presence of 50 vol% ethylene glycol or 50 vol% dimethyl sulfoxide, only a single reversible ordered----liquid-crystalline transition is observed. This single ordered----liquid-crystalline transition exhibits a smaller enthalpy and occurs at a lower temperature than the major Polymorph II----liquid-crystal transition observed for dispersions in water alone. These results indicate that metastable polymorphism in C16:0-CER is related to hydration.

  13. Diketopyrrolopyrrole-based Conjugated Polymers Bearing Branched Oligo(Ethylene Glycol) Side Chains for Photovoltaic Devices.

    PubMed

    Chen, Xingxing; Zhang, Zijian; Ding, Zicheng; Liu, Jun; Wang, Lixiang

    2016-08-22

    Conjugated polymers are essential for solution-processable organic opto-electronic devices. In contrast to the great efforts on developing new conjugated polymer backbones, research on developing side chains is rare. Herein, we report branched oligo(ethylene glycol) (OEG) as side chains of conjugated polymers. Compared with typical alkyl side chains, branched OEG side chains endowed the resulting conjugated polymers with a smaller π-π stacking distance, higher hole mobility, smaller optical band gap, higher dielectric constant, and larger surface energy. Moreover, the conjugated polymers with branched OEG side chains exhibited outstanding photovoltaic performance in polymer solar cells. A power conversion efficiency of 5.37 % with near-infrared photoresponse was demonstrated and the device performance could be insensitive to the active layer thickness.

  14. Polyion-counterion interactions in sodium carboxymethylcellulose-ethylene glycol-water ternary solutions.

    PubMed

    Sharma, Ramesh; Das, Chanchal; Dahal, Sanjay; Das, Bijan

    2013-02-15

    Polyion-counterion interactions in sodium carboxymethylcellulose-ethylene glycol-water ternary system have been investigated with special reference to their variations with the polyelectrolyte concentration, the medium relative permittivity and the temperature using electrical conductance measurements. The experimental data have been analyzed on the basis of a model for semidilute polyelectrolyte conductivity which takes into account the scaling arguments proposed by Dobrynin et al. Concentration-dependent moderate counterion condensation (24-33%) was observed. Counterion condensation is found to be spontaneous which depends upon the EG-content of the medium and the temperature. A major proportion of the current is transported by the carboxymethylcellulose polyions. The results further demonstrated that the monomer units experience more frictional resistance in solution as the EG-content increases or as the temperature decreases.

  15. 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.

  16. Radiation grafting of oligo(ethylene glycol) ethyl ether methacrylate on polypropylene

    NASA Astrophysics Data System (ADS)

    Komasa, Justyna; Miłek, Andrzej; Ulański, Piotr; Rosiak, Janusz M.

    2014-01-01

    Oligo(ethylene glycol) ethyl ether methacrylate (OEGMA) can be grafted onto polypropylene (PP) films by post-irradiation grafting, forming a thermosensitive polymer layer, as indicated by FT-IR and contact angle measurements. In the first step, PP foils are irradiated by electron beam (5.5 kGy/min, up to 300 kGy) in the presence of air. Subsequently, the irradiated foils react with the monomer in oxygen-free solutions in isopropanol (up to 2 M of monomer) at 70 °C. Degree of grafting of OEGMA can be controlled by proper selection of absorbed dose, monomer concentration and reaction time. This work is a part of a broader project on thermosensitive materials facilitating cell growth and detachment for optimizing cell layer engineering techniques in the treatment of burn wounds.

  17. Reproductive toxicity of ethylene glycol monoethyl ether tested by continuous breeding of CD-1 mice

    SciTech Connect

    Lamb, J.C. IV; Gulati, D.K.; Russell, V.S.; Hommel, L.; Sabharwal, P.S.

    1984-08-01

    The reproductive toxicity of ethylene glycol monoethyl ether (EGEE) was evaluated in the Fertility Assessment by Continuous Breeding protocol. Both male and female CD-1 mice were given 0, 0.5, 1.0 or 2% EGEE in the drinking water and were housed as breeding pairs continuously for 14 weeks. Significant adverse effects on fertility were seen at 1 and 2% but not at 0.5%. After the continuous breeding phase of this test was completed, treated males were housed with control females and treated females with control males and fertility and reproduction were compared to the corresponding pairs of control male and control female mice. Both males and females from the 1 and 2% groups were affected. Testicular atrophy decreased sperm motility and increased abnormal sperm were noted in the treated males, but no specific anomalies were detected in the females. 7 references, 1 figure, 7 tables.

  18. Improved anticoagulation of titanium by sequential immobilization of oligo(ethylene glycol) and 2-methacryloyloxyethyl phosphorylcholine.

    PubMed

    Pan, Chang-Jiang; Hou, Yan-Hua; Liu, Heng-Quan; Ding, Hong-Yan; Dong, Yun-Xiao

    2013-12-01

    Titanium and its alloys have been widely used for blood-contacting biomedical devices; however, their blood compatibility needs to be improved. In this study, titanium surface was modified by sequential immobilization of oligo(ethylene glycol) (OEG) and 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve its anticoagulation. Water contact angle results showed an excellent hydrophilic surface after the immobilization. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) confirmed that OEG and MPC were successfully immobilized on titanium surface. Static platelet adhesion and APTT (activated partial thromboplastin time) experiments suggested that the anticoagulation of titanium was significantly enhanced by the immobilization of OEG and further by subsequent MPC grafting. The approach in the present study opens up a window of promising an effective and efficient method to improve the anticoagulation of blood-contact biomedical devices such as coronary stents.

  19. Poly(ethylene glycol)-stabilized silver nanoparticles for bioanalytical applications of SERS spectroscopy.

    PubMed

    Shkilnyy, Andriy; Soucé, Martin; Dubois, Pierre; Warmont, Fabienne; Saboungi, Marie-Louise; Chourpa, Igor

    2009-09-01

    The present work depicts the efficient one-step synthesis and detailed evaluation of stable aqueous colloids of silver nanoparticles (NPs) coated with poly(ethylene glycol) (PEG) covalently attached to their surface. Due to steric repulsion between polymer-modified surfaces, the stability of the nanoparticle suspension was preserved even at high ionic strength (0.1 M NaCl). At the same time, the PEG coating remains sufficiently permeable to allow surface-enhanced Raman scattering (SERS) from micromolar concentrations of small molecules such as the anticancer drug mitoxantrone (MTX). The enhancement efficiency of the hot spot-free Ag-PEG was compared to that of citrate-stabilized Ag colloids used after pre-aggregation. The potential of the polymer-stabilized colloids developed in this study is discussed in terms of bioanalytical applications of SERS spectroscopy.

  20. Effect of Moringa oleifera Lam. root-wood on ethylene glycol induced urolithiasis in rats.

    PubMed

    Karadi, Ravindra V; Gadge, Navneet B; Alagawadi, K R; Savadi, Rudraprabhu V

    2006-04-21

    In India, drumstick (Moringa oleifera Lam. (Moringaceae)) is commonly used as a phytotherapeutic agent. The effect of oral administration of aqueous and alcoholic extract of Moringa oleifera root-wood on calcium oxalate urolithiasis has been studied in male Wistar albino rats. Ethylene glycol feeding resulted in hyperoxaluria as well as increased renal excretion of calcium and phosphate. Supplementation with aqueous and alcoholic extract of Moringa oleifera root-wood significantly reduced the elevated urinary oxalate, showing a regulatory action on endogenous oxalate synthesis. The increased deposition of stone forming constituents in the kidneys of calculogenic rats was also significantly lowered by curative and preventive treatment using aqueous and alcoholic extracts. The results indicate that the root-wood of Moringa oleifera is endowed with antiurolithiatic activity.

  1. Low-temperature synthesis of metal tungstates nanocrystallites in ethylene glycol

    SciTech Connect

    Chen Di; Shen Guozhen; Tang Kaibin; Zheng Huagui; Qian Yitai

    2003-11-26

    In this paper, we report the low-temperature synthesis of metal tungstate, MWO{sub 4} (M=Ca, Sr, Ba, Cd, Zn, Pb) nanocrystallites. By reaction between metal chloride and sodium tungstate in ethylene glycol at 180 deg. C for 10 h, well-crystallized tungstate particles were successfully obtained. Characterization by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) shows that the product powders consist of nanosize particles. Photoluminescence measurement reveals that the as-obtained CaWO{sub 4}, CdWO{sub 4}, and PbWO{sub 4} show excitonic peaks at about 430, 500 and 500 nm, respectively. The solvent and reaction conditions are important in the formation of the products.

  2. Ultrafine silver nanoparticles obtained from ethylene glycol at room temperature: catalyzed by tungstate ions.

    PubMed

    Li, Jin; Zhu, Junwu; Liu, Xiaoheng

    2014-01-07

    Ethylene glycol (EG) has been widely utilized to fabricate silver nanoparticles with uniform size and morphology. However, the majority of the work reported to date using EG routinely require not only heating, but also a surfactant. In the present paper, we report a surfactant-free and facile method for the synthesis of fairly monodisperse smaller silver nanoparticles (~6 nm) through the reaction of silver ions with EG by using tungstates (such as potassium tungstate, sodium tungstate) as catalysts at room temperature. Particularly, in this method, tungstates as catalysts can dramatically speed up the reduction of silver ions, and EG acts as both a solvent and a reducing agent to reduce silver ions to Ag metal. Meantime, we have carried out a series of experiments to investigate the performance of the as-prepared silver nanoparticles. It was found that the silver nanoparticles show excellent catalytic activity for the reduction of 4-nitrophenol in the presence of NaBH4.

  3. Spectral Reflectance of Duckweed (Lemna Gibba L.) Fronds Exposed to Ethylene Glycol

    NASA Technical Reports Server (NTRS)

    Dong, Weijin; Carter, Gregory A.; Barber, John T.

    2001-01-01

    When duckweed (Lemna Gibba L.) fronds are exposed to ethylene glycol (EG) anatomy is altered, allowing an increase in water uptake that causes a darkening of frond appearance. Spectroradiometry was used to quantify changes in frond reflectance that occurred throughout the 400-850 nm spectrum under various EG concentrations and exposure times. The threshold concentration of EG at which a reflectance change could be detected was between 35 and 40 mM, approximately the same as by visual observation. EG-induced changes in frond reflectance were maximum at concentrations of 50 mM or greater. Reflectance changes were detectable within 24h of exposure to 100 mM EG,2-3 days prior to changes in frond appearance. The spectroradiometry of duckweed may serve as a rapid and sensitive technique for detection of ecosystem exposure to EG and perhaps other stress agents.

  4. Interaction of CuCl2 with poly(ethylene glycol) under microwave radiation

    NASA Astrophysics Data System (ADS)

    Tverjanovich, A.; Grevtsev, A.; Bereznev, S.

    2017-01-01

    CuCl2 solutions various concentration in poly(ethylene glycol) (PEG) are treated with microwave (MW) radiation. Optical absorption and FT-IR spectra of the solutions before treatment and after treatment are discussed. It is proposed that before treatment Cu2+ ions have rhombic distorted octahedral coordination in solution with four oxygen atoms of PEG and two Cl‑ ions. These oxygen atoms can be from hydroxyl or ether groups of PEG, depending on the relative ration OH‑ groups and Cu2+ ions. MW treatment of the solution results in a two-step reaction divided in time. The first stage of MW treatment leads to the reduction of Cu2+ ions to Cu+ ions. At the second stage Cu+ ions are reduced to Cu0 forming high-purity copper nanoparticles. In the same time PEG transforms with a formation of carbonyl groups. The shape of the obtained nanoparticles depends on the molecular weight of the used PEG.

  5. Dissolution of biomacromolecules in organic solvents by nano-complexing with poly(ethylene glycol).

    PubMed

    Mok, Hyejung; Kim, Ho Jeong; Park, Tae Gwan

    2008-05-22

    Various biomacromolecules (BMs) such as proteins, DNA, and carbohydrates are extremely difficult to be dissolved in a single organic solvent phase for sustained release or targeted delivery formulation. In this study, three different BMs could be solubilized in selected organic solvents by forming poly(ethylene glycol) (PEG)-assisted nano-complexes while maintaining their structural integrity. Dynamic light scattering (DLS) and atomic force microscopy (AFM) analysis revealed that proteins, DNA, and carbohydrate polymers could be nano-complexed with PEG in various organic solvents. The diameter of nano-complexes decreased roughly from approximately 600 nm to approximately 100 nm with increasing weight ratio of PEG/BM. The present solubilization technique could be potentially applied for sustained release formulations of various therapeutic biological drugs.

  6. Catechol-grafted poly(ethylene glycol) for PEGylation on versatile substrates.

    PubMed

    Lee, Hyukjin; Lee, Kang Dae; Pyo, Kyung Bo; Park, Sung Young; Lee, Haeshin

    2010-03-16

    We report on catechol-grafted poly(ethylene) glycol (PEG-g-catechol) for the preparation of nonfouling surfaces on versatile substrates including adhesion-resistant PTFE. PEG-g-catechol was prepared by the step-growth polymerization of PEO to which dopamine, a mussel-derived adhesive molecule, was conjugated. The immersion of substrates into an aqueous solution of PEG-g-catechol resulted in robust PEGylation on versatile surfaces of noble metals, oxides, and synthetic polymers. Surface PEGylation was unambiguously confirmed by various surface analytical tools such as ellipsometry, goniometry, infrared spectroscopy, and X-ray photoelectron spectroscopy. Contrary to existing PEG derivatives that are difficult-to-modify synthetic polymer surfaces, PEG-g-catechol can be considered to be a new class of PEGs for the facile surface PEGylation of various types of surfaces.

  7. Thermal conductivity studies of metal dispersed multiwalled carbon nanotubes in water and ethylene glycol based nanofluids

    SciTech Connect

    Jha, Neetu; Ramaprabhu, S.

    2009-10-15

    High thermal conducting metal nanoparticles have been dispersed on the multiwalled carbon nanotubes (MWNTs) outer surface. Structural and morphological characterizations of metal dispersed MWNTs have been carried out using x-ray diffraction analysis, high resolution transmission electron microscopy, energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy. Nanofluids have been synthesized using metal-MWNTs in de-ionized water (DI water) and ethylene glycol (EG) base fluids. It has been observed that nanofluids maintain the same sequence of thermal conductivity as that of metal nanoparticles Ag-MWNTs>Au-MWNTs>Pd-MWNTs. A maximum enhancement of 37.3% and 11.3% in thermal conductivity has been obtained in Ag-MWNTs nanofluid with DI water and EG as base fluids, respectively, at a volume fraction of 0.03%. Temperature dependence study also shows enhancement of thermal conductivity with temperature.

  8. Photocatalytic current on a mercury electrode in acidified ethylene glycol solutions of tribenzylamine

    SciTech Connect

    Kokilashvili, R.G.; Dzhaparidze, Dzh.I.; Pleskov, Yu.V.

    1986-01-01

    In ethylene glycol solutions of acid on a mercury cathode in the presence of tribenzylamine (TrBA), catalytic currents of the liberation of hydrogen are observed. Under the same conditions, with illumination of the electrode, the authors detected photocurrents that can be interpreted as the light-stimulated catalytic liberation of hydrogen. In both cases the determining role, in all probability, is played by the tribenzylammonium cation adsorbed on mercury, according to the authors. Photocurrent was measured on an electrode in the form of a hanging mercury drop. An OSL-1 illuminator with DRSh-250 mercury lamp, with interface filters, was used to illuminate the electrode and in individual measurements an LPM-11 laser was used. The light intensity was varied with the aid of neutral glasses NG. The investigated process consists of photoreduction of adsorbed TrBAH/sup +/.

  9. Fabrication of anticoagulation layer on titanium surface by sequential immobilization of poly (ethylene glycol) and albumin.

    PubMed

    Pan, Chang-Jiang; Hou, Yan-Hua; Zhang, Bin-Bin; Zhang, Lin-Cai

    2014-01-01

    This paper presents a simple method to sequentially immobilize poly (ethylene glycol) (PEG) and albumin on titanium surface to enhance the blood compatibility. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis indicated that PEG and albumin were successfully immobilized on the titanium surface. Water contact angle results showed a better hydrophilic surface after the immobilization. The immobilized PEG or albumin can not only obviously prevent platelet adhesion and activation but also prolong activated partial thromboplastin time (APTT), leading to the improved anticoagulation. Moreover, immobilization of albumin on PEG-modified surface can further improve the anticoagulation. The approach in the present study provides an effective and efficient method to improve the anticoagulation of blood-contact biomedical devices such as coronary stents.

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

    NASA Astrophysics Data System (ADS)

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

    2017-05-01

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

  11. Thermo-acoustical molecular interaction study in binary mixtures of glycerol and ethylene glycol

    NASA Astrophysics Data System (ADS)

    Kaur, Kirandeep; Juglan, K. C.; Kumar, Harsh

    2017-07-01

    Ultrasonic velocity, density and viscosity are measured over the entire composition range for binary liquid mixtures of glycerol (CH2OH-CHOH-CH2OH) and ethylene glycol (HOCH2CH2OH) at different temperatures and constant frequency of 2MHz using ultrasonic interferometer, specific gravity bottle and viscometer respectively. Measured experimental values are used to obtained various acoustical parameters such as adiabatic compressibility, acoustic impedance, intermolecular free length, relaxation time, ultrasonic attenuation, effective molar weight, free volume, available volume, molar volume, Wada's constant, Rao's constant, Vander Waal's constant, internal pressure, Gibb's free energy and enthalpy. The variation in acoustical parameters are interpreted in terms of molecular interactions between the components of molecules of binary liquid mixtures.

  12. Development of Macroporous Poly(ethylene glycol) Hydrogel Arrays Within Microfluidic Channels

    PubMed Central

    Lee, Andrew G.; Arena, Christopher P.; Beebe, David J.; Palecek, Sean P.

    2010-01-01

    The mass transport of solutes through hydrogels is an important design consideration in materials used for tissue engineering, drug delivery, and protein arrays used to quantify protein concentration and activity. We investigated the use of poly(ethylene glycol) (PEG) as a porogen to enhance diffusion of macromolecules into the interior of polyacrylamide and PEG hydrogel posts photopatterned within microfluidic channels. The diffusion of GST–GFP and dextran–FITC into hydrogels was monitored and effective diffusion coefficients were determined by fitting to the Fickian diffusion equations. PEG-diacrylate (Mr 700) with porogen formed a macroporous structure and permitted significant penetration of 250 kDa dextran. Proteins copolymerized in these macroporous hydrogels retained activity and were more accessible to antibody binding than proteins copolymerized in nonporous gels. These results suggest that hydrogel macroporosity can be tuned to regulate macromolecular transport in applications such as tissue engineering and protein arrays. PMID:21028794

  13. MS-Monitored Conjugation of Poly(ethylene glycol) Monomethacrylate to RGD Peptides

    PubMed Central

    Bol’shakov, Oleg I.; Akala, Emmanuel O.

    2014-01-01

    Development of biologically active polymers is an active area of research due to their applications in varied and diverse fields of biomedical research: cell adhesion, tissue proliferation, and drug delivery. Recent advances in chemical modification allow fine-tuning of the properties of biomedical polymers to improve their applications: blood circulation half-life, stimuli-responsive degradation, site-specific targeting, drug loading, etc. In this article, convergent synthesis of polymerizable macromonomers bearing a site-specific ligand (RGD peptide) using a low molecular weight MA-poly(ethylene glycols) (PEGs) is presented. The method affords macromonomers useful as the starting materials to produce biomedical polymers. We found matrix assisted laser desorption/ionization mass spectromerty convenient in monitoring the conjugation process via step-by-step following of PEG modification. PMID:24976670

  14. An Improved Strategy for the Synthesis of Ethylene Glycol by Oxamate-Mediated Catalytic Hydrogenation.

    PubMed

    Satapathy, Anilkumar; Gadge, Sandip T; Bhanage, Bhalchandra M

    2017-04-10

    The present study reports an improved approach for the preparation of ethylene glycol (EG) by using carbon monoxide as C1 chemical by a two-step oxidative carbonylation and hydrogenation sequence. In the first step, oxamates are synthesized through oxidative cross double carbonylation of piperidine and ethanol by using Pd/C catalyst under phosphine ligand-free conditions and subsequently hydrogenated by Milstein's catalyst (carbonylhydrido[6-(di-t-butylphosphinomethylene)-2-(N,N-diethylaminomethyl)-1,6-dihydropyridine]ruthenium(II)). The presented stepwise oxamate-mediated coupling provides the basis for a new strategy for the synthesis of EG by selective upgrading of C1 chemicals. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Acoustic Levitator Power Device: Study of Ethylene-Glycol Water Mixtures

    NASA Astrophysics Data System (ADS)

    Caccamo, M. T.; Cannuli, A.; Calabrò, E.; Magazù, S.

    2017-05-01

    Acoustic levitator power device is formed by two vertically and opposed high output acoustic transducers working at 22 kHz frequency and produces sound pressure levels of 160 dB. The acoustic waves are monitored from an oscilloscope using a signal amplifier. The ability to perform contactless measurements, avoidance of undesired contamination from the container, are some of advantages of this apparatus. Acoustic levitation can be also used for sample preparation of high concentrated mixtures starting from solutions. In the present paper, an acoustic levitator power device is employed to collect data on levitated water mixtures of Ethylene Glycol (EG) which are then analysed by Infra-Red spectroscopy. The study allows to follow the drying process versus time and to obtain a gel-like compound characterized by an extended chemical crosslinking.

  16. Incorporation of Therapeutic Interventions in Physiologically Based Pharmacokinetic Modeling of Human Clinical Case Reports of Accidental or Intentional Overdosing with Ethylene Glycol

    SciTech Connect

    Corley, Rick A.; McMartin, K. E.

    2005-05-16

    Ethylene glycol is a high production volume chemical used in the manufacture of resins and fibers, antifreeze, deicing fluids, heat transfer and hydraulic fluids. Although occupational uses of ethylene glycol have not been associated with adverse effects, there are case reports where humans have either intentionally or accidentally ingested large quantities of ethylene glycol, primarily from antifreeze. The acute toxicity of ethylene glycol in humans and animals and can proceed through three stages, each associated with a different metabolite: central nervous system depression (ethylene glycol), cardiopulmonary effects associated with metabolic acidosis (glycolic acid) and ultimately renal toxicity (oxalic acid), depending upon the total amounts consumed and effectiveness of therapeutic interventions. A physiologically based pharmacokinetic (PBPK) model developed in a companion paper (Corley et al., 2004) was refined in this study to include clinically relevant treatment regimens for ethylene glycol poisoning such as hemodialysis or metabolic inhibition with either ethanol or fomepizole. Such modifications enabled the model to describe several human case reports which included analysis of ethylene glycol and/or glycolic acid. Such data and model simulations provide important confirmation that the PBPK model developed previously can adequately describe the pharmacokinetics of ethylene glycol in humans following low, occupational or environmentally relevant inhalation exposures, as well as massive oral doses even under conditions where treatments have been employed that markedly affect the disposition of ethylene glycol and glycolic acid. By integrating the case report data sets with controlled studies in this PBPK model, it was demonstrated that fomepizole, if administered early enough in a clinical situation, can be more effective than ethanol or hemodialysis in preventing the metabolism of ethylene glycol to more toxic metabolites. Hemodialysis remains an

  17. Quick freezing of unfertilized mouse oocytes using ethylene glycol with sucrose or trehalose.

    PubMed

    Rayos, A A; Takahashi, Y; Hishinuma, M; Kanagawa, H

    1994-01-01

    Unfertilized mouse oocytes were frozen by directly plunging them into liquid nitrogen vapour after equilibration in a freezing medium containing 3 mol ethylene glycol l-1 with 0.25 mol sucrose or trehalose l-1 for 5-40 min. After thawing and dilution of the cryoprotectant, oocytes of normal morphology were inseminated in vitro and the effect of equilibration period on the rates of fertilization and development in vitro was examined. Regardless of the equilibration in the freezing medium, no significant difference was observed on the fertilization rate of frozen-thawed oocytes. However, higher fertilization and higher normal fertilization rates were obtained with equilibration in 3 mol ethylene glycol l-1 with either 0.25 mol sucrose l-1 or trehalose for 20 and 40 min than with 5 and 10 min equilibration. Development rates to two-cell embryos and expanded blastocysts of in vitro fertilized frozen-thawed oocytes that were equilibrated in the freezing medium for 20 and 40 min were significantly higher (P < 0.05 or P < 0.01) than with 5 min equilibration. Development in vivo was assessed by transferring blastocysts derived from unfertilized oocytes frozen by the optimum treatment (20 min equilibration in the freezing medium before freezing) into the uterine horns of day 3 pseudopregnant female recipients. The development rate of frozen-thawed oocytes to the blastocyst stage after insemination in vitro was significantly lower than that of the non-frozen control (P < 0.001). However, transfer of the blastocysts derived from frozen-thawed oocytes to the uterine horns of the recipients in fetal development and implantation rates similar to those of the control.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Preparation and characterization of poly(propylene fumarate-co-ethylene glycol) hydrogels.

    PubMed

    Suggs, L J; Kao, E Y; Palombo, L L; Krishnan, R S; Widmer, M S; Mikos, A G

    1998-01-01

    We describe the preparation and bulk characterization of a cross-linked poly(propylene fumarate-co-ethylene glycol), p(PF-co-EG), hydrogel. Eight block copolymer formulations were made varying four different design parameters including: poly(ethylene glycol) (PEG) molecular weight, poly(propylene fumarate) (PPF) molecular weight, copolymer molecular weight, and ratio of PEG to PPF. Two different cross-linking formulations were also tested, one with a cross-linking monomer and one without. The extent of the cross-linking reaction and the degree of swelling in aqueous solution were determined on copolymer formulations made without a cross-linking monomer. The values of molecular weight between cross-links, Mc ranged from 300 +/- 120 to 1190 +/- 320 as determined from swelling data (n = 3). The equilibrium volume swelling ratios, Q, varied from 1.5 +/- 0.1 to 3.0 +/- 0.1. This ratio was found to increase with increasing PEG content in the copolymer and decrease with increasing PPF molecular weight. The values for complex dynamic elastic moduli magnitudes of E*, ranged from 0.9 +/- 0.2 to 13.1 +/- 1.1 MPa for the formulations with the cross-linking monomer, N-vinyl pyrrolidinone (VP) (n = 3). The ultimate tensile stresses on the formulations made with VP ranged from 0.15 +/- 0.03 to 1.44 +/- 1.06 MPa, and tensile moduli ranged from 1.11 +/- 0.20 to 20.66 +/- 2.42 MPa (n = 5). All of the mechanical properties increased with increasing PPF molecular weight and decreased with increasing PEG content in the copolymer. These data show that the physical properties of p(PF-co-EG) hydrogels can be tailored for specific applications by altering the material composition.

  19. Development of an AMBER-compatible transferable force field for poly(ethylene glycol) ethers (glymes).

    PubMed

    Barbosa, Nathalia S V; Zhang, Yong; Lima, Eduardo R A; Tavares, Frederico W; Maginn, Edward J

    2017-06-01

    An all-atom force field consistent with the general AMBER force field (GAFF) format for poly(ethylene glycol) dimethyl ether (diglyme or G2) was developed by fitting to experimental liquid densities and dielectric constants. Not surprisingly, the new force field gives excellent agreement with experimental liquid phase densities and dielectric constants over a wide temperature range. Other dynamic and thermodynamic properties of liquid G2 such as its self-diffusion coefficient, shear viscosity, and vaporization enthalpy were also calculated and compared to experimental data. For all of the properties studied, the performance of the proposed new force field is better than that of the standard GAFF force field. The force field parameters were transferred to model two other poly(ethylene glycol) ethers: monoglyme (G1) and tetraglyme (G4). The predictive ability of the modified force field for G1 and G4 was significantly better than that of the original GAFF force field. The proposed force field provides an alternative option for the simulation of mixtures containing glymes using GAFF-compatible force fields, particularly for electrochemical applications. The accuracy of a previously published force field based on the OPLS-AA format and the accuracies of two modified versions of that force field were also examined for G1, G2, and G4. It was found that the original OPLS-AA force field is superior to the modified versions of it, and that it has a similar accuracy to the proposed new GAFF-compatible force field. Graphical abstract Transferability of an AMBER-compatible force field parameterized for G2 to other glymes.

  20. Haematological and spermatotoxic effects of ethylene glycol monomethyl ether in copper clad laminate factories

    PubMed Central

    Shih, T.; Hsieh, A.; Liao, G.; Chen, Y.; Liou, S.

    2000-01-01

    OBJECTIVES—To investigate the effects of ethylene glycol monomethyl ether (EGME) on haematology and reproduction in exposed workers.
METHODS—53 Impregnation workers from two factories that make copper clad laminate with EGME as a solvent were recruited as the exposed group. Another group of 121 lamination workers with indirect exposure to EGME was recruited as the control group. Environmental monitoring of concentrations of EGME in air and biological monitoring of urinary methoxyacetic acid (MAA) concentrations were performed. Venous blood was collected for routine and biochemical analyses. Semen was collected from 14 workers exposed to EGME for sperm analysis and was compared with 13 control workers.
RESULTS—Results of haematological examination showed that the haemoglobin, packed cell volume, and red blood cell count in the male workers exposed to EGME were significantly lower than in the controls. The frequency of anaemia in the exposed group (26.1%) was significantly higher than in the control group (3.2%). However, no differences were found between the female workers exposed and not exposed to EGME. After adjustment for sex, body mass index, and duration of employment, red blood cell count was significantly negatively associated with air concentrations of EGME, and haemoglobin, packed cell volume, and red blood cell count were significantly negatively associated with urinary concentrations of MAA. The pH of semen in the exposed workers was significantly lower than in the control workers, but there were no significant differences in the sperm count or sperm morphology between the exposed and control groups.
CONCLUSION—It can be concluded that EGME is a haematological toxin, which leads to anaemia in the exposed workers. However, the data from this study did not support the theory of a spermatotoxic effect of EGME.


Keywords: ethylene glycol monomethyl ether; haematological disorders; spermatotoxicity PMID:10769301

  1. The role of serum proteins in Staphylococcus aureus adhesion to ethylene glycol coated surfaces.

    PubMed

    Schuster, Swen; Yu, Wenqi; Nega, Mulugeta; Chu, Ya-Yun; Zorn, Stefan; Zhang, Fajun; Götz, Friedrich; Schreiber, Frank

    2014-11-01

    Bacterial adhesion on implants is a first step in the development of chronic foreign body associated infections. Finding strategies to minimize bacterial adhesion may contribute to minimize such infections. It is known that surfaces with oligo-ethylene-glycol (EG3OMe) or poly-ethylene-glycol (PEG2k) terminations decrease unspecific protein adsorption and bacterial adhesion. However, little is known about the influence of serum and its components on bacterial adhesion. We therefore prepared two coatings on gold surface with HS-(CH2)11EG3OMe (EG3OMe) and PEG2k-thiol and studied the role of bovine serum albumin (BSA), γ-globulins, and serum on Staphylococcus aureus adhesion. While BSA and lysozyme showed no adherence even when applied at very high concentrations (100 mg/ml), γ-globulins adsorbed already from 10 mg/ml on. The adsorption of γ-globulins was, however, significantly decreased when it was mixed with BSA in a ratio of 3:1, as it is in the serum. Pretreatment of EG3OMe and PEG2k coatings with γ-globulins or serum strongly promoted adherence of S. aureus when resuspended in buffer, suggesting that γ-globulins play a pivotal role in promoting S. aureus adhesion by its IgG binding proteins; the finding that a spa-deletion mutant, lacking the IgG binding protein A, showed decreased adherence corroborated this. Similarly, when S. aureus was pretreated with serum or γ-globulins its adherence was also significantly decreased. Our findings show that particularly γ-globulins bind to the coated surfaces thus mediating adherence of S. aureus via its protein A. As pretreatment of S. aureus with serum or γ-globulins significantly decreased adherence, treatment of patients with γ-globulins before implant surgery might lower the risk of implant-associated infections. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    NASA Astrophysics Data System (ADS)

    Li, Xiaomeng; Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

    2012-01-01

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

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

    PubMed

    Mascitti, Andrea; Lupacchini, Massimiliano; Guerra, Ruben; Taydakov, Ilya; Tonucci, Lucia; d'Alessandro, Nicola; Lamaty, Frederic; Martinez, Jean; Colacino, Evelina

    2017-01-01

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

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

    PubMed Central

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

    2017-01-01

    The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene) glycols (PEGs), as safe grinding assisting agents (liquid-assisted grinding, LAG). A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents. In general, cleaner reaction profiles were observed in the presence of PEGs, compared to dry-grinding procedures. PMID:28179944

  5. Endogenous oxalogenesis after acute intravenous loading with ethylene glycol or glycine in rats receiving standard and vitamin B6-deficient diets.

    PubMed

    Teerajetgul, Yaovalak; Hossain, Rayhan Zubair; Machida, Noriko; Sugaya, Kimio; Ogawa, Yoshihide

    2008-10-01

    The effect on endogenous oxalate synthesis of acute intravenous loading with ethylene glycol or glycine was investigated in rats on a standard or a vitamin B6-deficient diet. Twenty-four male Wistar rats weighing approximately 180 g were randomly divided into ethylene glycol and glycine groups of 12 animals each. These groups were further divided into two subgroups of six animals each that were fed either a standard or a vitamin B6-deficient diet for 3 weeks. Animals of these two subgroups received an intravenous infusion of 20 mg (322.22 micromol) of ethylene glycol or 100 mg (1332.09 micromol) of glycine, respectively. Urine samples were collected just before intravenous infusion of each substance and at hourly intervals until 5 h after receiving the infusion. Urinary oxalate, glycolate, and citrate levels were measured by capillary electrophoresis. Urinary oxalate and glycolate excretion was significantly increased after ethylene glycol administration. Significant differences between the control and vitamin B6-deficient groups were found. In contrast, there were only small changes of oxalate and glycolate excretion after glycine administration. Recovery of the given dose of ethylene glycol as oxalate in 5-h urine was 0.31% and 7.15% in the control and vitamin B6-deficient groups, respectively, whereas recovery of glycolate was 0.68% and 7.22%, respectively. Ethylene glycol loading has a significant effect on urinary oxalate excretion in both normal and vitamin B6-deficient rats, whereas glycine loading only has a small effect. Oxalate and glycolate excretion after ethylene glycol loading were respectively 23-fold and 11-fold higher in vitamin B6-deficient rats than in controls.

  6. Assessing the toxic effects of ethylene glycol ethers using Quantitative Structure Toxicity Relationship models

    SciTech Connect

    Ruiz, Patricia; Mumtaz, Moiz; Gombar, Vijay

    2011-07-15

    Experimental determination of toxicity profiles consumes a great deal of time, money, and other resources. Consequently, businesses, societies, and regulators strive for reliable alternatives such as Quantitative Structure Toxicity Relationship (QSTR) models to fill gaps in toxicity profiles of compounds of concern to human health. The use of glycol ethers and their health effects have recently attracted the attention of international organizations such as the World Health Organization (WHO). The board members of Concise International Chemical Assessment Documents (CICAD) recently identified inadequate testing as well as gaps in toxicity profiles of ethylene glycol mono-n-alkyl ethers (EGEs). The CICAD board requested the ATSDR Computational Toxicology and Methods Development Laboratory to conduct QSTR assessments of certain specific toxicity endpoints for these chemicals. In order to evaluate the potential health effects of EGEs, CICAD proposed a critical QSTR analysis of the mutagenicity, carcinogenicity, and developmental effects of EGEs and other selected chemicals. We report here results of the application of QSTRs to assess rodent carcinogenicity, mutagenicity, and developmental toxicity of four EGEs: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol and their metabolites. Neither mutagenicity nor carcinogenicity is indicated for the parent compounds, but these compounds are predicted to be developmental toxicants. The predicted toxicity effects were subjected to reverse QSTR (rQSTR) analysis to identify structural attributes that may be the main drivers of the developmental toxicity potential of these compounds.

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

    PubMed

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

    2001-09-15

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

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

    PubMed

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

    2009-02-01

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

  9. Determination of trace amounts of ethylene glycol and its analogs in water matrixes by liquid chromatography/tandem mass spectrometry.

    PubMed

    Tran, Buu N; Okoniewski, Richard; Bucciferro, Anthony; Jansing, Robert; Aldous, Kenneth M

    2014-01-01

    Contamination of drinking water by ethylene glycol (EG) is a public health concern. EG causes adverse health effects in humans and animals, including cardiopulmonary and acute renal failure. EG and other glycols, such as propylene glycol (PG) are major components in antifreeze liquids, which may be the main source of contamination of ground water. A sensitive LC/electrospray ionization (ESI)-MS/MS method was developed to measure trace amounts of EG, diethylene glycol, and 1,2- and 1,3-PG in several water sources, including municipal tap, lake, river, and salinated water. In this method, glycols in water samples were derivatized with benzoyl chloride by the Schotten-Baumann reaction, followed by liquid-liquid extraction using pentane as the organic solvent prior to the LC/ESI-MS/MS determination. QC included analysis of a method blank and samples fortified at low and high levels. Analytical data showed excellent linear calibration for all observed glycols, with good precision and accuracy. The method detection limits for the studied glycols ranged from 1.9 to 6.1 ng/mL across the water matrixes tested. This method is suitable to help assess water quality in areas that may be prone to glycol contamination.

  10. Subchronic toxicity of ethylene glycol in Wistar and F-344 rats is related to metabolism and clearance of metabolites.

    SciTech Connect

    Cruzan, G; Corley, Rick A.; Hard, G; Mertens, J W.; McMartin, K. E.; Snellings, W; Gingell, Ralph; Deyo, J A.

    2004-10-01

    Ethylene Glycol (CAS RN 107-21-1) can to cause kidney toxicity via the formation of calcium oxalate crystals in a variety of species including humans. Numerous repeated dose studies conducted in rats have indicated that male rats are more susceptible than female rats. Furthermore, subchronic and chronic studies using different dietary exposure regimens have indicated that male Wistar rats may be more sensitive to renal toxicity than male F344 rats. This study was, therefore, conducted to compare the toxicity of ethylene glycol in the two strains of rats under identical exposure conditions and to evaluate the potential contribution of toxicokinetic differences to strain sensitivity. Ethylene glycol was mixed in the diet at concentrations to deliver constant target dosage levels of 0, 50, 150, 500, or 1000 mg/kg/day for 16 weeks to groups of 10 male Wistar and 10 male F-344 rats based upon weekly group mean body weights and feed consumption. Kidneys were examined histologically for calcium oxalate crystals and pathology. Samples of blood, urine and kidneys from satellite animals exposed to 0, 150, 500, or 1000 mg/kg/day for 1 or 16 weeks were analyzed for ethylene glycol, glycolic acid and oxalic acid. Treatment of Wistar rats at 1000 mg/kg/day resulted in the death of 2 rats; in addition, at 500 and 1000 mg/kg/day, group mean body weights were decreased compared to control throughout the 16 weeks. In F-344 rats exposed at 1000 mg/kg/day and in Wistar rats at 500 and 1000 mg/kg/day, there were lower urine specific gravities, higher urine volumes, and increased absolute and relative kidney weights. In both strains of rats treated at 500 and 1000 mg/kg/day, some or all treated animals had increased calcium oxalate crystals in the kidney tubules and crystal nephropathy. The effect was more severe in Wistar rats than in F-344 rats. Accumulation of oxalic acid in the kidneys of both strains of rats were consistent with the dose- and strain-dependent toxicity. As the

  11. Subchronic toxicity of ethylene glycol in Wistar and F-344 rats related to metabolism and clearance of metabolites.

    PubMed

    Cruzan, George; Corley, Richard A; Hard, Gordon C; Mertens, Jos J W M; McMartin, Kenneth E; Snellings, William M; Gingell, Ralph; Deyo, James A

    2004-10-01

    Ethylene glycol (CAS RN 107-21-1) can cause kidney toxicity via the formation of calcium oxalate crystals in a variety of species, including humans. Numerous repeated dose studies conducted in rats have indicated that male rats are more susceptible than female rats. Furthermore, subchronic and chronic studies using different dietary exposure regimens have indicated that male Wistar rats may be more sensitive to renal toxicity than male Fischer-344 (F-344) rats. This study was conducted to compare the toxicity of ethylene glycol in the two strains of rats under identical exposure conditions and to evaluate the potential contribution of toxicokinetic differences to strain sensitivity. Ethylene glycol was mixed in the diet at concentrations to deliver constant target dosage levels of 0, 50, 150, 500, or 1000 mg/kg/day for 16 weeks to groups of 10 male Wistar and 10 male F-344 rats based on weekly group mean body weights and feed consumption. Kidneys were examined histologically for calcium oxalate crystals and pathology. Samples of blood, urine, and kidneys from satellite animals exposed to 0, 150, 500, or 1000 mg/kg/day for 1 or 16 weeks were analyzed for ethylene glycol, glycolic acid, and oxalic acid. Treatment of Wistar rats at 1000 mg/kg/day resulted in the death of two rats; in addition, at 500 and 1000 mg/kg/day, group mean body weights were decreased compared to control throughout the 16 weeks. In F-344 rats exposed at 1000 mg/kg/day and in Wistar rats receiving 500 and 1000 mg/kg/day, there were lower urine specific gravities, higher urine volumes, and increased absolute and relative kidney weights. In both strains of rats treated at 500 and 1000 mg/kg/day, some or all treated animals had increased calcium oxalate crystals in the kidney tubules and crystal nephropathy. The effect was more severe in Wistar rats than in F-344 rats. Accumulation of oxalic acid in the kidneys of both strains of rats was consistent with the dose-dependent and strain

  12. NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Ethylene Glycol.

    PubMed

    2004-01-01

    The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for ethylene glycol (EG) to cause adverse effects on reproduction and development in humans. EG was selected for evaluation due to recent toxicity and occupational exposure information and widespread exposure in the general public. EG is a small, hydroxy-substituted hydrocarbon used as a chemical intermediate in the production of polyester compounds. It is also found in automotive anti-freeze, industrial coolants, hydraulic fluids, and windshield deicer fluids. The results of this evaluation on EG are published in a NTP-CERHR monograph which includes: 1) the Expert Panel Report on the Reproductive and Developmental Toxicity of Ethylene Glycol, 2) the NTP Brief, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to EG on human development and reproduction based on the conclusions of the NTP-CERHR Expert Panel Report and the public comments received on that report. These conclusions concurred with those of the expert panel. First, although EG could possibly affect human development if exposures are sufficiently high, there is negligible concern for developmental effects in humans at current proposed/estimated exposure levels. There is no direct evidence that exposure of people to EG adversely affects reproduction or development, but studies reviewed by the expert panel show that oral exposure to high doses of EG can adversely affect development in mice and rats. These studies indicate doses that exceed saturation of the glycolic acid metabolism are needed to produce developmental toxicity. Proposed exposure scenarios constructed by the expert panel and current proposed/estimated exposure levels suggest that human exposures are at least 100- to 1000-fold lower than the dose expected to result in metabolic

  13. Aggregation behavior of poly(ethylene glycol-bl-propylene sulfide) di- and triblock copolymers in aqueous solution.

    PubMed

    Cerritelli, Simona; O'Neil, Conlin P; Velluto, Diana; Fontana, Antonella; Adrian, Marc; Dubochet, Jacques; Hubbell, Jeffrey A

    2009-10-06

    Block copolymers of poly(ethylene glycol)-bl-poly(propylene sulfide) (PEG-PPS) have recently emerged as a new macromolecular amphiphile capable of forming a wide range of morphologies when dispersed in water. To understand better the relationship between stability and morphology in terms of the relative and absolute block compositions, we have synthesized a collection of PEG-PPS block copolymers and quantified their critical aggregation concentration and observed their morphology using cryogenic transmission electron microscopy after thin film hydration with extrusion and after solvent dispersion from tetrahydrofuran, a solvent for both blocks. By understanding the relationship between aggregate character and block copolymer architecture, we have observed that whereas the relative block lengths control morphology, the stability of the aggregates upon dilution is determined by the absolute block length of the hydrophobic PPS block. We have compared results obtained with PEG-PPS to those obtained with poly(ethylene glycol)-bl-poly(propylene oxide)-bl-poly(ethylene glycol) block copolymers (Pluronics). The results reveal that the PEG-PPS aggregates are substantially more stable than Pluronic aggregates, by more than an order of magnitude. PEG-PPS can form a wide variety of stable or metastable morphologies in dilute solution within normal time and temperature ranges, whereas Pluronics can generally form only spherical micelles under the same conditions. On the basis of these results, block copolymers of PEG with poly(propylene sulfide) may present distinct advantages over those with poly(propylene glycol) for a number of applications.

  14. A sensitive estimation of residual ethylene glycol in ethylene oxide sterilized medical devices by HPLC with electrospray ionization mass spectrometric detection.

    PubMed

    Hari, P R; Naseerali, C P; Sreenivasan, K

    2009-01-15

    A novel analytical methodology for the estimation of residual ethylene glycol (EG) in ethylene oxide sterilized polymer is reported. The method involves the monitoring of ammonium adduct of EG ions in the presence of 10 mM ammonium acetate buffer and methanol using electrospray ionization liquid chromatography and mass spectrometry (LC-ESI-MS). The method enables the detection and quantification of EG without prior derivatization up to a level of 0.06 microg/ml. The potentiality of the method is demonstrated by estimating EG in ethylene oxide (EtO) sterilized polyethylene terephthalate fabric used in heart valve sewing ring. The method is simple, rapid and can routinely be used for the quantification of residual EG in EtO sterilized medical devices.

  15. Synthesis and characterization of poly(methoxyl ethylene glycol-caprolactone-co-methacrylic acid-co-poly(ethylene glycol) methyl ether methacrylate) pH-sensitive hydrogel for delivery of dexamethasone.

    PubMed

    Wang, Ke; Xu, Xu; Wang, YuJun; Yan, Xi; Guo, Gang; Huang, MeiJuan; Luo, Feng; Zhao, Xia; Wei, YuQuan; Qian, ZhiYong

    2010-04-15

    In this work, a novel pH-sensitive hydrogels based on macromonomer of methoxyl poly(ethylene glycol)-poly(caprolactone)-acryloyl chloride (MPEG-PCL-AC, PCE-AC), poly(ethylene glycol) methyl ether methacrylate (MPEGMA), and methacrylic acid (MAA) were successfully synthesized by heat-initiated free radical polymerization method. The obtained macromonomers and hydrogels were characterized by (1)H NMR and FT-IR, respectively. Morphology study, swelling behavior, in vitro drug release behavior, acute oral toxicity of hydrogels, and cytotoxicity of PCE-AC macromonomer were also investigated in this paper. Finally, the hydrogels demonstrated that the sharp change in different pH value, thus believing to be promising the suitability of the candidate for oral drug-delivery systems.

  16. Engineering oligo(ethylene glycol) based nonfouling surfaces and microstructures for biomedical applications

    NASA Astrophysics Data System (ADS)

    Ma, Hongwei

    This thesis presents the initial development of oligo(ethylene glycol) (OEG) based "nonfouling"---protein and cell resistant---coatings that can be applied to a wide range of biomedical applications. The hypothesis underlying this work is that a high density of OEG will eliminate nonspecific protein adsorption thus reduce or eradicate undesired surface phenomena, such as poor biocompatibility, which are direct consequences of the nonspecific protein adsorption. A generalized method for creating functionalized nonfouling surfaces was developed by combining two strategies, namely "Surface-Initiated Atom Transfer Radical Polymerization of Oligo(ethylene glycol) methyl methacrylate (SI-ATRP of OEGMA)" and "Modular design of initiator", demonstrated on gold (metallic materials), glass and silicon oxide (hydroxylated substrates). SI-ATRP was able to achieve an OEG coating with a density higher than all the pre-existing techniques could achieve. It also provided control over the coating thickness and architecture that are not easily controlled by other techniques. Thickness-density profile of poly(OEGMA) was constructed based on SI-ATRP from mixed SAMs on gold. For the first time, we constructed a map of protein resistance of PEG coated surfaces, which reveals the relationship between the poly(OEGMA) coatings and their protein adsorption. Besides its scientific implications, the practical use (from an engineering point of view) of these results is that the information shall be instructive in designing nonfouling surfaces by providing critical structural parameters. This thesis also demonstrates integration of SI-ATRP with micro and nano scale pattern fabrication, which further expands the applications of this technology. In vitro cell culturing on patterned surfaces confirmed that high-density OEG coatings were exceptionally nonfouling even in physiological milieu, which shows great promise for the in vivo study of OEG coatings. A prototype protein microarray was

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

    PubMed

    Davidovich-Pinhas, Maya; Bianco-Peled, Havazelet

    2011-07-01

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

  18. An ethylene glycol intercalated monometallic layered double hydroxide based on iron as an efficient bifunctional catalyst.

    PubMed

    Nagarajan, Rajamani; Gupta, Pankaj; Singh, Poonam; Chakraborty, Pinki

    2016-11-01

    Given the fact that the literature describing the intercalation of organic molecules in monometallic LDH systems is scarce, the present investigation is aimed at the generation of ethylene glycol intercalated Fe(II)-Fe(III) LDH with the objective of enhancing the surface area for further catalytic applications of industrially important and environmentally harmful organics. The solvothermal reaction of FeCl3 with urea in an ethylene glycol medium yielded a brown colored powder which was characterized employing a wide range of analytical techniques including high resolution powder X-ray diffraction (PXRD), scanning electron microscopy, thermal analysis, X-ray photo electron spectroscopy (XPS), elemental (C, H, N and S) analysis, UV-visible, photoluminescence spectroscopy measurements, BET surface area and pore-size analysis. The observed reflections in the PXRD pattern were indexed in a rhombohedral symmetry with a = 3.175 and c = 31.9 Å. Combining the results from the Fe 2p core level analysis and anion contents from elemental and thermogravimetric analysis, a formula of Fe(2+)1.06 Fe(3+)0.94 (O2C2H4) (OH)4 was deduced for the sample. The intercalation of EG in the interlayer was confirmed from FTIR and Raman spectroscopy measurements. The d-d transitions of the Fe(3+)-ion and the charge transfer transition of the Fe(ii)-Fe(iii) lattice were evident in the UV-visible spectrum. Blue indigoid emission bands arising from the transitions present in the Fe(3+)-ion were noticed in the photoluminescence spectrum. The measured BET surface area and pore diameter of the sample were 144 m(2) g(-1) and 12.5 nm, respectively. Almost instant decolourisation of the Xylenol Orange (XO) dye occurred in the presence of H2O2 and the LDH sample as catalyst. Similar observations were encountered for Methyl Orange (MO) and Methylene Blue (MB) dyes. All these reactions followed pseudo first-order kinetics. The industrially important reductive conversion of nitro aromatics was catalyzed

  19. Steam Reforming of Ethylene Glycol over MgAl₂O₄ Supported Rh, Ni, and Co Catalysts

    SciTech Connect

    Mei, Donghai; Lebarbier, Vanessa M.; Xing, Rong; Albrecht, Karl O.; Dagle, Robert A.

    2015-11-25

    Steam reforming of ethylene glycol (EG) over MgAl₂O₄ supported metal (15 wt.% Ni, 5 wt.% Rh, and 15 wt.% Co) catalysts were investigated using combined experimental and theoretical methods. Compared to highly active Rh and Ni catalysts with 100% conversion, the steam reforming activity of EG over the Co catalyst is comparatively lower with only 42% conversion under the same reaction conditions (500°C, 1 atm, 119,000 h⁻¹, S/C=3.3 mol). However, CH₄ selectivity over the Co catalyst is remarkably lower. For example, by varying the gas hour space velocity (GHSV) such that complete conversion is achieved for all the catalysts, CH₄ selectivity for the Co catalyst is only 8%, which is much lower than the equilibrium CH₄ selectivity of ~ 24% obtained for both the Rh and Ni catalysts. Further studies show that varying H₂O concentration over the Co catalyst has a negligible effect on activity, thus indicating zero-order dependence on H₂O. These experimental results suggest that the supported Co catalyst is a promising EG steam reforming catalyst for high hydrogen production. To gain mechanistic insight for rationalizing the lower CH₃ selectivity observed for the Co catalyst, the initial decomposition reaction steps of ethylene glycol via C-O, O-H, C-H, and C-C bond scissions on the Rh(111), Ni(111) and Co(0001) surfaces were investigated using density functional theory (DFT) calculations. Despite the fact that the bond scission sequence in the EG decomposition on the three metal surfaces varies, which leads to different reaction intermediates, the lower CH₄ selectivity over the Co catalyst, as compared to the Rh and Ni catalysts, is primarily due to the higher barrier for CH₄ formation. The higher S/C ratio enhances the Co catalyst stability, which can be elucidated by the facile water dissociation and an alternative reaction path to remove the CH species as a coking precursor via the HCOH formation. This work was financially supported by the United

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

    PubMed

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

    2016-03-01

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

  1. Insulin Particle Formation in Supersaturated Aqueous Solutions of Poly(Ethylene Glycol)

    PubMed Central

    Bromberg, Lev; Rashba-Step, Julia; Scott, Terrence

    2005-01-01

    Protein microspheres are of particular utility in the field of drug delivery. A novel, completely aqueous, process of microsphere fabrication has been devised based on controlled phase separation of protein from water-soluble polymers such as polyethylene glycols. The fabrication process results in the formation of spherical microparticles with narrow particle size distributions. Cooling of preheated human insulin-poly(ethylene glycol)-water solutions results in the facile formation of insulin particles. To map out the supersaturation conditions conducive to particle nucleation and growth, we determined the temperature- and concentration-dependent boundaries of an equilibrium liquid-solid phase separation. The kinetics of formation of microspheres were followed by dynamic and continuous-angle static light scattering techniques. The presence of PEG at a pH that was close to the protein's isoelectric point resulted in rapid nucleation and growth. The time elapsed from the moment of creation of a supersaturated solution and the detection of a solid phase in the system (the induction period, tind) ranged from tens to several hundreds of seconds. The dependence of tind on supersaturation could be described within the framework of classical nucleation theory, with the time needed for the formation of a critical nucleus (size <10 nm) being much longer than the time of the onset of particle growth. The growth was limited by cluster diffusion kinetics. The interfacial energies of the insulin particles were determined to be 3.2–3.4 and 2.2 mJ/m2 at equilibrium temperatures of 25 and 37°C, respectively. The insulin particles formed as a result of the process were monodisperse and uniformly spherical, in clear distinction to previously reported processes of microcrystalline insulin particle formation. PMID:16254391

  2. Online Aerosol Mass Spectrometry of Single Micrometer-Sized Particles Containing Poly(ethylene glycol)

    SciTech Connect

    Bogan, M J; Patton, E; Srivastava, A; Martin, S; Fergenson, D; Steele, P; Tobias, H; Gard, E; Frank, M

    2006-10-25

    Analysis of poly(ethylene glycol)(PEG)-containing particles by online single particle aerosol mass spectrometers equipped with laser desorption ionization (LDI) is reported. We demonstrate that PEG-containing particles are useful in the development of aerosol mass spectrometers because of their ease of preparation, low cost, and inherently recognizable mass spectra. Solutions containing millimolar quantities of PEGs were nebulized and, after drying, the resultant micrometer-sized PEG containing particles were sampled. LDI (266 nm) of particles containing NaCl and PEG molecules of average molecular weight <500 generated mass spectra reminiscent of mass spectra of PEG collected by other MS schemes including the characteristic distribution of positive ions (Na{sup +} adducts) separated by the 44 Da of the ethylene oxide units separating each degree of polymerization. PEGs of average molecular weight >500 were detected from particles that also contained t the tripeptide tyrosine-tyrosine-tyrosine or 2,5-dihydroxybenzoic acid, which were added to nebulized solutions to act as matrices to assist LDI using pulsed 266 nm and 355 nm lasers, respectively. Experiments were performed on two aerosol mass spectrometers, one reflectron and one linear, that each utilize two time-of-flight mass analyzers to detect positive and negative ions created from a single particle. PEG-containing particles are currently being employed in the optimization of our bioaerosol mass spectrometers for the application of measurements of complex biological samples, including human effluents, and we recommend that the same strategies will be of great utility to the development of any online aerosol LDI mass spectrometer platform.

  3. Oligo(ethylene glycol)-functionalized disiloxanes as electrolytes for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengcheng; Dong, Jian; West, Robert; Amine, Khalil

    Functionalized disiloxane compounds were synthesized by attaching oligo(ethylene glycol) chains, -(CH 2CH 2O)- n, n = 2-7, via hydrosilation, dehydrocoupling, and nucleophilic substitution reactions and were examined as non-aqueous electrolyte solvents in lithium-ion cells. The compounds were fully characterized by 1H, 13C, and 29Si nuclear magnetic resonance (NMR) spectroscopy. Upon doping with lithium bis(oxalato)borate (LiBOB) or LiPF 6, the disiloxane electrolytes showed conductivities up to 6.2 × 10 -4 S cm -1 at room temperature. The thermal behavior of the electrolytes was studied by differential scanning calorimetry, which revealed very low glass transition temperatures before and after LiBOB doping and much higher thermal stability compared to organic carbonate electrolytes. Cyclic voltammetry measurements showed that disiloxane-based electrolytes with 0.8 M LiBOB salt concentration are stable to 4.7 V. The LiBOB/disiloxane combinations were found to be good electrolytes for lithium-ion cells; unlike LiPF 6, LiBOB can provide a good passivation film on the graphite anode. The LiPF 6/disiloxane electrolyte was enabled in lithium-ion cells by adding 1 wt% vinyl ethylene carbonate (VEC). Full cell performance tests with LiNi 0.80Co 0.15Al 0.05O 2 as the cathode and mesocarbon microbead (MCMB) graphite as the anode show stable cyclability. The results demonstrate that disiloxane-based electrolytes have considerable potential as electrolytes for use in lithium-ion batteries.

  4. [Decontamination of some spices by ethylene oxide. Development of 2-chloroethanol and ethylene glycol during the preservation].

    PubMed

    Chaigneau, M; Muraz, B

    1993-01-01

    After the disinfection by ethylene oxide and storage by ethylene oxide in definite conditions of 16 spices (parsley, chervil, tarragone, chive, thyme, rosemary, coriander, nutmeg, mace, cinnamon, allspices, clove, pepper), the authors observed the fast loss of residual ethylene oxide and ethyleneglycol. On the contrary, the persistence of 2-chloroethanol was followed up for 6 months. They turn their attention to the toxicity of this compound to ensure the protection of customers.

  5. Equations for obtaining melting points for the ternary system ethylene glycol/sodium chloride/water and their application to cryopreservation.

    PubMed

    Woods, E J; Zieger, M A; Gao, D Y; Critser, J K

    1999-06-01

    The present study describes the H(2)O-NaCl-ethylene glycol ternary system by using a differential scanning calorimeter to measure melting points (T(m)) of four different ratios (R) of ethylene glycol to NaCl and then devising equations to fit the experimental measurements. Ultimately an equation is derived which characterizes the liquidus surface above the eutectic for any R value in the system. This study focuses on ethylene glycol in part because of recent evidence indicating it may be less toxic to pancreatic islets than Me(2)SO, which is currently used routinely for islet cryopreservation. The resulting physical data and previously determined information regarding the osmotic characteristics of canine pancreatic islets are combined in a mathematical model to describe the volumetric response to equilibrium-rate freezing in varying initial concentrations of ethylene glycol. Copyright 1999 Academic Press.

  6. Synthesis of branched poly(methyl methacrylate)s via controlled/living polymerisations exploiting ethylene glycol dimethacrylate as branching agent.

    PubMed

    Isaure, Francoise; Cormack, Peter A G; Graham, Susan; Sherrington, David C; Armes, Steven P; Bütun, Vural

    2004-05-07

    With appropriate choice of reaction composition and conditions, copolymerisation of methyl methacrylate and ethylene glycol dimethacrylate using Cu-based ATRP or GTP methodologies yields soluble branched polymers in facile one-pot reactions.

  7. 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

  8. Proton nuclear magnetic resonance spectroscopic detection and determination of ethylene glycol dimethacrylate as a contaminant of methyl methacrylate raw material.

    PubMed

    Hanna, G M; Lau-Cam, C A

    1995-01-01

    A simple, specific, and accurate proton nuclear magnetic resonance (1H NMR) spectroscopic method is presented for detection and assay of ethylene glycol dimethacrylate dimer as a contaminant of methyl methacrylate monomer. In addition to minimizing exposure of the analyst to the irritant and toxic methacrylic acid esters, the proposed method requires no sample preparation. Quantitations are based on integrals for signals of methylene protons of ethylene glycol dimethacrylate at 4.37 ppm and methyl protons of methyl methacrylate at 3.70 ppm. Analysis of 10 synthetic mixtures of the monomer with 1-11% of dimer yielded a dimer recovery of 100.5 +/- 2.05% (mean +/- standard deviation). Correspondence (correlation coefficient, r = 0.9999) between the amount of dimer added and the amount found was excellent. The proposed method measures as little as 1% of dimer.

  9. Prophylactic effect of coconut water (Cocos nucifera L.) on ethylene glycol induced nephrocalcinosis in male wistar rat.

    PubMed

    Gandhi, M; Aggarwal, M; Puri, S; Singla, S K

    2013-01-01

    Many medicinal plants have been employed during ages to treat urinary stones though the rationale behind their use is not well established. Thus, the present study was proposed to evaluate the effect of coconut water as a prophylactic agent in experimentally induced nephrolithiasis in a rat model. The male Wistar rats were divided randomly into three groups. Animals of group I (control) were fed standard rat diet. In group II, the animals were administrated 0.75% ethylene glycol in drinking water for the induction of nephrolithiasis. Group III animals were administrated coconut water in addition to ethylene glycol. All the treatments were continued for a total duration of seven weeks. Treatment with coconut water inhibited crystal deposition in renal tissue as well as reduced the number of crystals in urine. Furthermore, coconut water also protected against impaired renal function and development of oxidative stress in the kidneys. The results indicate that coconut water could be a potential candidate for phytotherapy against urolithiasis.

  10. Performance of AA5052 alloy anode in alkaline ethylene glycol electrolyte with dicarboxylic acids additives for aluminium-air batteries

    NASA Astrophysics Data System (ADS)

    Wang, DaPeng; Zhang, DaQuan; Lee, KangYong; Gao, LiXin

    2015-11-01

    Dicarboxylic acid compounds, i.e. succinic acid (SUA), adipic acid (ADA) and sebacic acid (SEA), are used as electrolyte additives in the alkaline ethylene glycol solution for AA5052 aluminium-air batteries. It shows that the addition of dicarboxylic acids lowers the hydrogen gas evolution rate of commercial AA5052 aluminium alloy anode. AA5052 aluminium alloy has wide potential window for electrochemical activity and better discharge performance in alkaline ethylene glycol solution containing dicarboxylic acid additives. ADA has the best inhibition effect for the self-corrosion of AA5052 anode among the three dicarboxylic acid additives. Fourier transform infrared spectroscopy (FT-IR) reveals that dicarboxylic acids and aluminium ions can form coordination complexes. Quantum chemical calculations shows that ADA has a smaller energy gap (ΔE, the energy difference between the lowest unoccupied orbital and the highest occupied orbital), indicating that ADA has the strongest interaction with aluminium ions.

  11. 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.

  12. Development of poly(propylene fumarate-co-ethylene glycol) as an injectable carrier for endothelial cells.

    PubMed

    Suggs, L J; Mikos, A G

    1999-01-01

    Poly(propylene fumarate-co-ethylene glycol) [P(PF-co-EG)] hydrogels were examined as in situ polymerizable carriers for endothelial cells. The temperature increase from 37 degrees C during cross-linking was measured. The maximum temperature did not increase above 38.3 degrees C for any copolymer formulation. The temperature profiles also appeared to be independent of the amount or molecular weight of poly(ethylene glycol). These materials were polymerized in situ in a subcutaneous rat model and evaluated for initial biocompatibility. A normal wound-healing response was seen with formation and subsequent maturity of a fibrous capsule. Endothelial cells were embedded in vitro during the cross-linking process and their proliferation was assessed over the first 24 h. There was significant DNA synthesis by the embedded endothelial cells during this time period. These data suggest that P(PF-co-EG) hydrogels could be developed for use as injectable cell carriers.

  13. Influence of ethylene glycol on CaCO 3 particles formation via carbonation in the gas-slurry system

    NASA Astrophysics Data System (ADS)

    Konopacka-łyskawa, Donata; Lackowski, Marcin

    2011-04-01

    Calcium carbonate precipitation was investigated in the gas-slurry system in the reaction of calcium hydroxide and carbon dioxide. The precipitation process was occurred in the presence of ethylene glycol (EG). The used organic additive changed the viscosity of reactive mixture, the solubility of carbon dioxide and the solubility of calcium carbonate which influence CaCO 3 precipitation conditions. The course of reaction was monitored by conductivity probe. The increase concentration of ethylene glycol in the reactive mixture caused higher CO 2 usage to achieve the end point of reaction. Calcium carbonate was precipitated as calcite and produced CaCO 3 particles formed agglomerates in all experiments. The size of obtained CaCO 3 particles decreased when the EG concentration increased from 0% to 15% (by vol.). The further increase of EG concentration in solution up to 20% resulted in an increase of the size of CaCO 3 particles.

  14. Outcome of patients in acute poisoning with ethylene glycol--factors which may have influence on evolution.

    PubMed

    Tanasescu, A; Macovei, R A; Tudosie, M S

    2014-01-01

    Intoxication with ethylene glycol occurs as a result of intentional ingestion in suicide attempts or accidentally. Clinical ethylene glycol poisoning is not specific and occurs in many poisoning cases therefore the diagnosis is difficult. Early diagnostic and establishment of therapy are very important for a favorable evolution. The mortality rate of ethylene glycol intoxication ranges between 1 and 22% depending on the amount of alcohol ingestion and the time period between alcohol ingestion and initiation of therapy. Retrospectively analyzed data from 18 patients admitted with ethylene glycol poisoning in the emergency department between 2011 and 2012. The following were taken into consideration: incidence of intoxication in the group study, medical history, the amount ingested and the time since the ingestion of ethylene glycol and the admission to hospital, presence of metabolic acidosis and laboratory test results on admission (urea, creatinine osmolar or anion gaps), the treatment initiated and the outcome of the patient. 18 patients with ethylene glycol intoxication were admitted to hospital between 2011 and 2012. The initial diagnosis based on a detailed clinical history in combination with the presence of metabolic acidosis with elevation of the osmolar or anion gaps. 12 of the 18 patients were man (66%) and age range interval was between 23 and 77 years. The time from the ingestion of ethylene glycol and the admission to hospital was between 30 minutes and older than 24 hours. 14 patients have been presented earlier to the hospital, between 30 minutes and 12 hours (in the first part of the clinical stage) and 13 of the 14 patients had a favorable evolution. One of these patients had an unfavorable evolution. Regarding this patient, the amount ingested was unknown. 10 of the 18 patients had a voluntary ingestion (55,55%) and 6 of the 18 patients had an alcoholism medical history. The amount ingested by the patients was between 20 ml and 500 ml. Metabolic

  15. Ethylene glycol poisoning in three dogs: Importance of early diagnosis and role of hemodialysis as a treatment option.

    PubMed

    Schweighauser, A; Francey, T

    2016-02-01

    Poisoning with ethylene glycol as contained in antifreeze can rapidly lead to irreversible acute renal failure and other organ damage. It carries a grave prognosis unless diagnosed early and adequate treatment is initiated within 8 hours of ingestion. Toxicity of ethylene glycol is related to the production of toxic metabolites by the enzyme alcohol dehydrogenase (ADH), leading to early signs of severe polyuria (PU) and polydipsia (PD), gastritis, ataxia and central nervous depression, followed by progressive dehydration, and ultimately oligoanuric renal failure. In addition to general supportive care, therapeutic interventions must include either antidotes blocking ADH-mediated metabolism or blood purification techniques to remove both the parent compound and the toxic metabolites. The goal of this case report is to describe three cases of acute antifreeze intoxication in dogs, and to discuss treatment options available for this poisoning.

  16. Analysis of different synthetic homopolymers by the use of a new calculation software for tandem mass spectra.

    PubMed

    Baumgaertel, Anja; Scheubert, Kerstin; Pietsch, Bernhard; Kempe, Kristian; Crecelius, Anna C; Böcker, Sebastian; Schubert, Ulrich S

    2011-06-30

    The manual interpretation of tandem mass spectra of synthetic polymers is very time-consuming. Therefore, a new software tool was developed to accelerate the interpretation of spectra obtained without requiring any further knowledge about the polymer class or the fragmentation behavior under high-energy collision-induced dissociation (CID) conditions. The software only requires an alphabetical list of elements and a peak list of the measured substance as an xml file for the evaluation of the chosen mass spectrum. Tandem mass spectra of different homopolymers, like poly(2-oxazoline)s, poly(ethylene glycol) and poly(styrene), were interpreted by the new software tool. This contribution describes a fast and automated software tool for the rapid analysis of homopolymers. Copyright © 2011 John Wiley & Sons, Ltd.

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

    SciTech Connect

    Bharti, Shivani; Tripathi, S. K.; Kaur, Gurvir; Gupta, Shikha

    2015-08-28

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

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Bharti, Shivani; Kaur, Gurvir; Gupta, Shikha; Tripathi, S. K.

    2015-08-01

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

  20. Microgel formation in the free radical crosslinking copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethcrylate (EGDMA)

    SciTech Connect

    Xiudong Sung; Yuen-Yuen Chiu; Lee, L.J.

    1996-12-31

    The formation of heterogeneous structure through intramolecular reaction is an important feature in the free radical crosslinking copolymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA). Such structure formation affects not only the curing behavior but also the rheological changes of the resin. In this work, the effect of co-monomer composition on the reaction kinetics, rheological changes and microgel formation of MMA-EGDMA copolymerization was studied. A percolation model was adopted to simulate such monovinyl-divinyl reactions.

  1. Adapting biodegradable oligo(poly(ethylene glycol) fumarate) hydrogels for pigment epithelial cell encapsulation and lens regeneration.

    PubMed

    Zhang, Mimi W; Park, Hansoo; Guo, Xuan; Nakamura, Kenta; Raphael, Robert M; Kasper, F Kurtis; Mikos, Antonios G; Tsonis, Panagiotis A

    2010-04-01

    This study investigated the encapsulation of newt iris pigment epithelial cells (PECs), which have the ability to regenerate a lens by trans-differentiation in vivo, within a biodegradable hydrogel of oligo(poly(ethylene glycol) fumarate) crosslinked with poly(ethylene glycol)-diacrylate. Hydrogel beads of initial diameter of 1 mm were fabricated by a molding technique. The swelling ratio and degradation rate of the hydrogel beads decreased with increasing crosslinking ratios. Confocal microscopy confirmed the cytocompatibility of crosslinking hydrogel formulations as evidenced by the viability of an encapsulated model cell line within a crosslinked hydrogel bead. Hydrogel beads encapsulating iris PECs were also implanted into lentectomized newts in vivo; histological evaluation of explants after 30 days revealed a regenerated lens, thus demonstrating that the presence of degrading hydrogel did not adversely affect lens regeneration. The results of this study suggest the potential of a method for lens regeneration involving oligo(poly(ethylene glycol) fumarate) hydrogels for iris PEC encapsulation and transplantation.

  2. Adapting Biodegradable Oligo(Poly(Ethylene Glycol) Fumarate) Hydrogels for Pigment Epithelial Cell Encapsulation and Lens Regeneration

    PubMed Central

    Zhang, Mimi W.; Park, Hansoo; Guo, Xuan; Nakamura, Kenta; Raphael, Robert M.; Kasper, F. Kurtis

    2010-01-01

    This study investigated the encapsulation of newt iris pigment epithelial cells (PECs), which have the ability to regenerate a lens by trans-differentiation in vivo, within a biodegradable hydrogel of oligo(poly(ethylene glycol) fumarate) crosslinked with poly(ethylene glycol)-diacrylate. Hydrogel beads of initial diameter of 1 mm were fabricated by a molding technique. The swelling ratio and degradation rate of the hydrogel beads decreased with increasing crosslinking ratios. Confocal microscopy confirmed the cytocompatibility of crosslinking hydrogel formulations as evidenced by the viability of an encapsulated model cell line within a crosslinked hydrogel bead. Hydrogel beads encapsulating iris PECs were also implanted into lentectomized newts in vivo; histological evaluation of explants after 30 days revealed a regenerated lens, thus demonstrating that the presence of degrading hydrogel did not adversely affect lens regeneration. The results of this study suggest the potential of a method for lens regeneration involving oligo(poly(ethylene glycol) fumarate) hydrogels for iris PEC encapsulation and transplantation. PMID:19514850

  3. The effect of oculo-acupuncture on recovery from ethylene glycol-induced acute renal injury in dogs.

    PubMed

    Liu, Jianzhu; Song, Kun-Ho; You, Myung-Jo; Son, Dong-Soo; Cho, Sung-Whan; Kim, Duck-Hwan

    2007-01-01

    The potential recovery effect by oculo-acupuncture (OA) on ethylene glycol-induced acute renal injury in dogs was investigated. Acute renal damage was induced by ingestion of ethylene glycol in six mongrel dogs. The dogs were assigned to control (three dogs) and experimental (three dogs) groups. The control group did not receive any treatment, while the experimental group was treated with oculo-acupuncture at kidney/urinary bladder region plus zhong jiao region of the eyes after the induction of renal damage. Serum blood urea nitrogen (BUN), creatinine, sodium (Na), chloride (Cl), and potassium (K) were measured in both control and experimental groups. The blood RBC and Hb were also examined. The serum BUN and creatinine activities in the experimental group were lower than those in the control group, the serum Na and Cl had the irregular change in both groups, and the blood Hb in the control and experimental group showed decreasing tendency. Significant differences were observed on the 3rd and 7th day in BUN, 7th day in creatinine, 2nd day in Na and Cl, and 7th day in Hb when compared to the control group. Whereas, serum K concentration and RBC in the experimental group did not change significantly. The recovery findings of the renal injury were also observed in the experimental group histopathologically. In conclusion, OA therapy (kidney/urinary bladder region plus zhong jiao region) was effective for recovery of the renal injury induced by ethylene glycol in dogs.

  4. Oligomer-to-polymer transition in short ethylene glycol chains connected to mobile hydrophobic anchors.

    PubMed

    Tanaka, Motomu; Rehfeldt, Florian; Schneider, Matthias F; Gege, Christian; Schmidt, Richard R; Funari, Sérgio S

    2005-01-01

    We studied the structure of short ethylene glycol (EG) chains with N repeating units (EGN, N = 3, 6, 9, 12, and 15) connected to hydrophobic dihexadecyl chains by means of a combination of differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS/WAXS). These synthetic amphiphiles dispersed in water form planar lamellar stacks and hexagonal cylinders confining the EG chains to restricted geometries. Owing to the self-assembly of the anchoring points, the lateral density of EG chains in planar lamella can be quantitatively controlled. Furthermore, the chain-melting phase transition of the anchors enables us to "switch" the intermolecular distance reversibly. SAXS/WAXS results suggest that the shorter EG chains (N = 3, 6, and 9) assume a helical conformation in stacks of planar lamella. When the EG chains are further elongated (N = 12 and 15), the lamellar periodicities cannot be explained by a linear extrapolation of shorter oligomers, but can be interpreted well as polymer brushes following the scaling theorem. Such rich phase behaviors of EGN molecules can be used as a simple model of oligo/poly-saccharide chains on cell surfaces, which act not only as flexible repellers between neighboring cells but also as stable spacers for functional ligands.

  5. Lubricin is expressed in chondrocytes derived from osteoarthritic cartilage encapsulated in poly (ethylene glycol) diacrylate scaffold.

    PubMed

    Musumeci, G; Loreto, C; Carnazza, M L; Coppolino, F; Cardile, V; Leonardi, R

    2011-01-01

    Osteoarthritis (OA) is characterized by degenerative changes within joints that involved quantitative and/or qualitative alterations of cartilage and synovial fluid lubricin, a mucinous glycoprotein secreted by synovial fibroblasts and chondrocytes. Modern therapeutic methods, including tissue-engineering techniques, have been used to treat mechanical damage of the articular cartilage but to date there is no specific and effective treatment. This study aimed at investigating lubricin immunohistochemical expression in cartilage explant from normal and OA patients and in cartilage constructions formed by Poly (ethylene glycol) (PEG) based hydrogels (PEG-DA) encapsulated OA chondrocytes. The expression levels of lubricin were studied by immunohistochemistry: i) in tissue explanted from OA and normal human cartilage; ii) in chondrocytes encapsulated in hydrogel PEGDA from OA and normal human cartilage. Moreover, immunocytochemical and western blot analysis were performed in monolayer cells from OA and normal cartilage. The results showed an increased expression of lubricin in explanted tissue and in monolayer cells from normal cartilage, and a decreased expression of lubricin in OA cartilage. The chondrocytes from OA cartilage after 5 weeks of culture in hydrogels (PEGDA) showed an increased expression of lubricin compared with the control cartilage. The present study demonstrated that OA chondrocytes encapsulated in PEGDA, grown in the scaffold and were able to restore lubricin biosynthesis. Thus our results suggest the possibility of applying autologous cell transplantation in conjunction with scaffold materials for repairing cartilage lesions in patients with OA to reduce at least the progression of the disease.

  6. Coupled molecular dynamics-stochastic model for thermal conductivity of ethylene glycol based copper nanofluid.

    PubMed

    Ghosh, M M; Rai, R K

    2014-04-01

    A coupled molecular dynamics (MD)-stochastic simulation based model has been proposed here for the thermal conductivity of ethylene glycol (EG) based copper nanofluid. The model is based on the thermal evolution of the nanoparticles dispersed in the nanofluid which is in contact with a heat source. It is natural that the nanoparticles dispersed in the nanofluid would move randomly by Brownian motion and repeatedly collide with the heat source. During each collision the nanoparticles would extract some heat by conduction mode from the heat source and this heat would be dissipated to the base fluid during Brownian motion by a combination of conduction and microconvection mode. Thus, in addition to normal conductive heat transfer through the base fluid (EG) itself (without nanoparticles) some amount of heat is transferred by the collision of the nanoparticles with the heat source. The extent of this additional heat transfer has been estimated in the present model to estimate the enhancement in thermal conductivity of EG based copper nanofluid, as a function of volume fraction loading of nanoparticles. The prediction of the present model has been compared with the experimental data available in literature, and it has shown a reasonable agreement between the theoretical prediction and the experimental data.

  7. Comparative study of the viscoelastic mechanical behavior of agarose and poly(ethylene glycol) hydrogels.

    PubMed

    Roberts, Justine J; Earnshaw, Audrey; Ferguson, Virginia L; Bryant, Stephanie J

    2011-10-01

    This study presents a comparative investigation into differences in the mechanical properties between two hydrogels commonly used in cartilage tissue engineering [agarose vs. poly(ethylene glycol) (PEG)], but which are formed through distinctly different crosslinking mechanisms (physical vs. covalent, respectively). The effects of hydrogel chemistry, precursor concentration, platen type (nonporous vs. porous) used in compression bioreactors, and degradation (for PEG) on the swelling properties and static and dynamic mechanical properties were examined. An increase in precursor concentration resulted in decreased equilibrium mass swelling ratios but increased equilibrium moduli and storage moduli for both hydrogels (p < 0.05). Agarose displayed large stress relaxations and a frequency dependence indicating its viscoelastic properties. Contrarily, PEG hydrogels displayed largely elastic behavior with minimal stress relaxation and frequency dependence. In biodegradable PEG hydrogels, the largely elastic behavior was retained during degradation. The type of platen did not affect static mechanical properties, but porous platens led to a reduced storage modulus for both hydrogels implicating fluid flow. In summary, agarose and PEG exhibit vastly different mechanical behaviors; a finding largely attributed to differences in their chemistries and fluid movement. Taken together, these design choices (hydrogel chemistry/structure, loading conditions) will likely have a profound effect on the tissue engineering outcome. Copyright © 2011 Wiley Periodicals, Inc.

  8. Rheological and recovery properties of poly(ethylene glycol) diacrylate hydrogels and human adipose tissue.

    PubMed

    Patel, Parul Natvar; Smith, Connie Kathleen; Patrick, Charles W

    2005-06-01

    The viscosity and elastic and viscous moduli of poly(ethylene glycol) diacrylate (PEGDA) hydrogels and human abdominal adipose tissue are measured as a function of shear rate and frequency. Results indicate that both materials exhibit shear thinning and are viscoelastic in nature. Rheological tests suggest that the hydrogels become firmer as strain and frequency increase. Adipose tissue, however, begins to fail at higher strains and frequencies. This behavior is confirmed by measuring the complex modulus of both materials as a function of strain. Recovery properties are also measured for each material as a function of deformation. Although PEGDA hydrogels are able to recover up to 78% of their original height after 15% deformation, adipose tissue is not able to recover over the range of deformations tested. The frequencies and strains over which the tests are conducted are those physiologically experienced by the human body. The hydrogels are able to withstand this range of forces and, hence, are appropriate for use as a soft tissue filler material. In addition, the hydrogels swell 38.1% +/- 0.9% independent of surface area. The complex modulus of hydrogels of varying polymer concentrations is also measured as a function of strain to determine the effects of changing polymer content. These results indicate that as polymer content increases, the hydrogels become firmer due to the higher number of polymer chains and behave more elastically. Copyright 2005 Wiley Periodicals, Inc.

  9. An FT-IR study on intramolecular hydrogen-bonding in ethylene glycol derivatives

    NASA Astrophysics Data System (ADS)

    Singelenberg, F. A. J.; van der Maas, J. H.; Kroon-Batenburg, L. M. J.

    1991-05-01

    The OH-streching region of a number of mono-alkyl ethers of (poly) ethylene glycols in dilute CCl 4 solution has been investigated by FT-IR. Non-H-bonded conformers are observed in addition to intramolecularly H-bonded ones. Different H-bonds can be distinguished when more than one ether-oxygen is present. The frequency of the non-bonded conformer is identical for all compounds and the same holds for the 5-R conformer. Furthermore the relative intensities of these peaks are identical in all spectra. The OH-frequency of the 8-R and 11-R conformers depends on the length and the type of the chain substituted at O(3) and O(4), respectively. MM2 calculations have been carried out for some of the compounds. The stability of the conformers proves to be in the order 11-R&>;5-R&>;;8-R&>; non-H-bonded. Interatomic distances and angles indicate that the H-bonds in the 8-R and 11-R conformers are bifurcated and "trifurcated", respectively.

  10. Ethylene glycol adjusted nanorod hematite film for active photoelectrochemical water splitting.

    PubMed

    Fu, Li; Yu, Hongmei; Li, Yongkun; Zhang, Changkun; Wang, Xunying; Shao, Zhigang; Yi, Baolian

    2014-03-07

    We reported a facile adjusted method for the synthesis of high surface area nanorod hematite film as a photoanode for application in water splitting. Crystalline hematite nanorods (EG-α-Fe2O3) are fabricated by electrodeposition in Fe(2+) precursor solution with the addition of ethylene glycol (EG) and followed by annealing at 450 °C. The nanorod hematite film fabricated by the modified electrodeposition approach exhibits a more uncompact structure than α-Fe2O3 obtained by directly electrodepositing on the FTO substrate. The optical and structural characteristics of the obtained film are also tested. The results infer that EG can tune the morphology of hematite and improve the photoabsorption in the visible light region due to its inducement of one-dimensional growth of crystal hematite. It also enhances the photoresponse activity of hematite in water splitting by improving the activities at the semiconductor/solution interface. The photocurrent density of EG-α-Fe2O3 nanorods increased to 0.24 mA cm(-2) at 1.4 V vs. RHE in 1 M KOH (pH = 13.6), almost 5 times higher than the original α-Fe2O3 (0.05 mA cm(-2), measured under the same conditions).

  11. Synthesis and characterization of macroporous poly(ethylene glycol)-based hydrogels for tissue engineering application.

    PubMed

    Sannino, A; Netti, P A; Madaghiele, M; Coccoli, V; Luciani, A; Maffezzoli, A; Nicolais, L

    2006-11-01

    Peptide activated poly(ethylene glycol) (PEG)-based hydrogels have received wide attention as material for tissue engineering application. However, the close structure of these materials may pose severe barriers to tissue invasion and nutrient transport. The aim of this work was to synthesize highly interconnected macroporous PEG hydrogels, suitable for use as tissue engineering scaffolds, by combining the photocrosslinking reaction with a foaming process. In particular, various porous samples, differing for both the polymer molecular weight and concentration in the starting precursor solution, have been prepared and characterized by means of scanning electron microscopy and mercury porosimetry. Moreover, water swelling properties have been evaluated and compared with those of the conventional nonporous ones, by performing both equilibrium and kinetic swelling measurements in distilled water. Results indicated that foamed hydrogels display a well-interconnected porous network, suitable for tissue invasion and free molecular trafficking within them. Pores dimension as well as swelling rate can be modulated by polymer concentrations and bubbling agent composition in the precursor solution.

  12. Contaminated soils (III): in vitro dermal absorption of ethylene glycol and nonylphenol in human skin.

    PubMed

    Moody, Richard P; Joncas, Julie; Richardson, Mark; Petrovic, Sanya; Chu, Ih

    2010-01-01

    Dermal absorption of contaminants from soils at federal contaminated sites in Canada was investigated using one hydrophile, (14)C-ethylene glycol (EG), and one lipophile, (14)C-nonylphenol (NP). In vitro dermal absorption of EG and NP was examined in dermatomed (0.4-0.5 mm) human skin using Bronaugh Teflon flow-through cells with Hanks HEPES buffered (pH 7.4) receiver solution with 4% bovine serum albumin (BSA). Tests were conducted under occlusive conditions with and without a commercial gardening soil spiked with EG or NP applied to skin at a soil load of 5 mg/cm(2). With percent absorption in skin depot included, a total of 9.9 + or - 6.28% (n = 6) and 34.8 + or - 8.47% (n = 6) absorption of EG with and without soil, respectively, and 20.6 + or - 5.56% (n = 7) and 41.1 + or - 6.46% (n = 7) of NP, with and without soil, respectively, were obtained. For tests without soil a reverse pattern was observed with significantly lower percent absorption into the receiver than depot with the lipophile NP, but significantly higher percent absorption in receiver versus depot for the hydrophile EG. This pattern was different in tests with soil, and caution needs to be exercised when extrapolating data from in vitro tests conducted without soil in human health risk assessments at contaminated sites.

  13. 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

  14. Thermal contraction of aqueous glycerol and ethylene glycol solutions for optimized protein-crystal cryoprotection.

    PubMed

    Shen, Chen; Julius, Ethan F; Tyree, Timothy J; Moreau, David W; Atakisi, Hakan; Thorne, Robert E

    2016-06-01

    The thermal contraction of aqueous cryoprotectant solutions on cooling to cryogenic temperatures is of practical importance in protein cryocrystallography and in biological cryopreservation. In the former case, differential contraction on cooling of protein molecules and their lattice relative to that of the internal and surrounding solvent may lead to crystal damage and the degradation of crystal diffraction properties. Here, the amorphous phase densities of aqueous solutions of glycerol and ethylene glycol at T = 77 K have been determined. Densities with accuracies of <0.5% to concentrations as low as 30%(w/v) were determined by rapidly cooling drops with volumes as small as 70 pl, assessing their optical clarity and measuring their buoyancy in liquid nitrogen-argon solutions. The use of these densities in contraction matching of internal solvent to the available solvent spaces is complicated by several factors, most notably the exclusion of cryoprotectants from protein hydration shells and the expected deviation of the contraction behavior of hydration water from bulk water. The present methods and results will assist in developing rational approaches to cryoprotection and an understanding of solvent behavior in protein crystals.

  15. Shape Dependent Thermal Conductivity of TiO2-Deionized Water and Ethylene Glycol Dispersion.

    PubMed

    Pal, Bhupender; Mallick, Soumya Suddha; Pal, Bonamali

    2015-05-01

    This paper presents the importance of different shapes and crystal phases of TiO2 nanostructures such as TiO2 P-25 (70:30 anatase and rutile), as-prepared nanorods (pure anatase) and sodium titanate nanotubes (orthorhombic Na2Ti2O5 x H2O crystal) on the thermal conductivity of de-ionized water and ethylene glycol. It revealed that TiO2 nanorods (L x W = 81-134 nm x 8-13 nm and surface area = 79 m2 g(-1)) showed always higher thermal conductivity than porous nanotubes (L x W = 85-115 nm x 9-12 nm and surface area = 176 m2 g(-1)) and commercial TiO2 P-25 (30-55 nm surface area = 56 m2 g(-1)), which was explained by their differences in crystallinity, crystal phases, compactness, surface exposed atoms, surface area and much greater mean free path of longitudinal phonon vibrations along its lateral dimensions. The subsequent effect of sonication time from 5-10 h results into the breakdown of TiO2 nanorods cluster (42 to 28 nm) with the instantaneous increase in negative zeta potential values from -31 to -45 mV, respectively, seems to be an additional cause for enhancement in its thermal conductivity.

  16. Molecular dynamics of ethylene glycol dimethacrylate glass former: influence of different crystallization pathways.

    PubMed

    Viciosa, María T; Correia, Natália T; Salmerón Sánchez, Manuel; Gómez Ribelles, José L; Dionísio, Madalena

    2009-10-29

    The crystallization induced by different thermal treatments of a low molecular weight glass former, ethylene glycol dimethacrylate (EGDMA), was investigated by dielectric relaxation spectroscopy (DRS) and differential scanning calorimetry (DSC). The fully amorphous material, dielectrically characterized for the first time, exhibits three relaxation processes: the alpha-relaxation related to dynamic glass transition whose relaxation rate obeys a Vogel-Fulcher-Tamman-Hesse (VFTH) law and two secondary processes (beta and gamma) with Arrhenius temperature dependence. Therefore, the evaluation of distinct crystallization pathways driven by different thermal histories was accomplished by monitoring the mobility changes in the multiple dielectric relaxation processes. Besides isothermal cold-crystallization, nonisothermal crystallizations coming from both the melt and the glassy states were induced. While an amorphous fraction, characterized by a glass transition, remains subsequent to crystallization from the melt, no alpha-relaxation is detected after the material undergoes nonisothermal cold-crystallization. In the latter, the secondary relaxations persist with a new process that evolves at low frequencies, designated as alpha' that was also detected at advanced crystallization states under isothermal cold-crystallization. Under the depletion of the alpha-relaxation, the beta-process when detected becomes better resolved keeping the same location prior to crystallization leading to a decoupled temperature dependence relative to the alpha-process.

  17. Thermal conductivity and viscosity measurements of ethylene glycol-based Al2O3 nanofluids

    PubMed Central

    2011-01-01

    The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction. The thermal conductivity and viscosity were experimentally determined at temperatures ranging from 283.15 K to 323.15 K using an apparatus based on the hot-wire method and a rotational viscometer, respectively. It has been found that both thermal conductivity and viscosity increase with the concentration of nanoparticles, whereas when the temperature increases the viscosity diminishes and the thermal conductivity rises. Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available. New viscosity experimental data yield values more than twice larger than the base fluid. The influence of particle size on viscosity has been also studied, finding large differences that must be taken into account for any practical application. These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity. PMID:21711737

  18. A tetra(ethylene glycol) derivative of benzothiazole aniline enhances Ras-mediated spinogenesis.

    PubMed

    Megill, Andrea; Lee, Taehee; DiBattista, Amanda Marie; Song, Jung Min; Spitzer, Matthew H; Rubinshtein, Mark; Habib, Lila K; Capule, Christina C; Mayer, Michael; Turner, R Scott; Kirkwood, Alfredo; Yang, Jerry; Pak, Daniel T S; Lee, Hey-Kyoung; Hoe, Hyang-Sook

    2013-05-29

    The tetra(ethylene glycol) derivative of benzothiazole aniline, BTA-EG4, is a novel amyloid-binding small molecule that can penetrate the blood-brain barrier and protect cells from Aβ-induced toxicity. However, the effects of Aβ-targeting molecules on other cellular processes, including those that modulate synaptic plasticity, remain unknown. We report here that BTA-EG4 decreases Aβ levels, alters cell surface expression of amyloid precursor protein (APP), and improves memory in wild-type mice. Interestingly, the BTA-EG4-mediated behavioral improvement is not correlated with LTP, but with increased spinogenesis. The higher dendritic spine density reflects an increase in the number of functional synapses as determined by increased miniature EPSC (mEPSC) frequency without changes in presynaptic parameters or postsynaptic mEPSC amplitude. Additionally, BTA-EG4 requires APP to regulate dendritic spine density through a Ras signaling-dependent mechanism. Thus, BTA-EG4 may provide broad therapeutic benefits for improving neuronal and cognitive function, and may have implications in neurodegenerative disease therapy.

  19. A Tetra(Ethylene Glycol) Derivative of Benzothiazole Aniline Enhances Ras-Mediated Spinogenesis

    PubMed Central

    Megill, Andrea; Lee, Taehee; DiBattista, Amanda Marie; Song, Jung Min; Spitzer, Matthew H.; Rubinshtein, Mark; Habib, Lila K.; Capule, Christina C.; Mayer, Michael; Turner, R. Scott; Kirkwood, Alfredo; Yang, Jerry; Pak, Daniel T. S.; Lee, Hey-Kyoung

    2013-01-01

    The tetra(ethylene glycol) derivative of benzothiazole aniline, BTA-EG4, is a novel amyloid-binding small molecule that can penetrate the blood–brain barrier and protect cells from Aβ-induced toxicity. However, the effects of Aβ-targeting molecules on other cellular processes, including those that modulate synaptic plasticity, remain unknown. We report here that BTA-EG4 decreases Aβ levels, alters cell surface expression of amyloid precursor protein (APP), and improves memory in wild-type mice. Interestingly, the BTA-EG4-mediated behavioral improvement is not correlated with LTP, but with increased spinogenesis. The higher dendritic spine density reflects an increase in the number of functional synapses as determined by increased miniature EPSC (mEPSC) frequency without changes in presynaptic parameters or postsynaptic mEPSC amplitude. Additionally, BTA-EG4 requires APP to regulate dendritic spine density through a Ras signaling-dependent mechanism. Thus, BTA-EG4 may provide broad therapeutic benefits for improving neuronal and cognitive function, and may have implications in neurodegenerative disease therapy. PMID:23719799

  20. Synthesis and Thermal Responses of Polygonal Poly(ethylene glycol) Analogues.

    PubMed

    Kawasaki, Shunichi; Muraoka, Takahiro; Hamada, Tsutomu; Shigyou, Kazuki; Nagatsugi, Fumi; Kinbara, Kazushi

    2016-04-05

    As a new type of topological poly(ethylene glycol) (PEG) analogue, a series of polygonal PEGs with digonal to hexagonal structures were developed. Polygonal PEGs with structures between the digonal and tetragonal types showed molecular-level dispersion in water at 20 °C, whereas the pentagonal and hexagonal PEGs aggregated, which is suggestive of enhanced hydrophobicity by ring expansion. Heating induced conformational changes in the polygonal PEGs and increased their hydrophobicity. Among the polygonal PEGs, only the trigonal and hexagonal PEGs showed a distinct thermal response to form and increase the size of the aggregates, respectively. Given that tetragonal and pentagonal PEGs only marginally responded to heat treatment, the thermal responses are likely due to a topological effect. At low temperatures, the larger polygonal PEGs are more restricted despite the expanded rings. The trigonal PEG showed the largest change in mobility, whereas the tetragonal PEG exhibited the smallest change. Hence, the topology of the polygonal PEGs influences the intramolecular packing and the local dynamics.

  1. Pure iron nanoparticles prepared by electric arc discharge method in ethylene glycol

    NASA Astrophysics Data System (ADS)

    Hosseynizadeh Khezri, S.; Yazdani, A.; Khordad, R.

    2012-09-01

    Pure iron nanoparticles (NPs) are fabricated using a simple and low-cost electric arc-discharge method in ethylene glycol (EG). The effect of different arc discharge currents (10, 20 and 30 A) on the size and optical absorption of the NPs is studied. Dynamic light scattering (DLS) and UV-visible spectroscopy data indicate that at the arc current of 10 A, the size of the particles is about 103 nm, and it can raise the arc current leading to larger NPs. UV-visible spectroscopy data show that the solvent gets more and more transparent with time, an effect which, sonication, proves that is related to agglomeration of the NPs. The evidence of pure Fe NPs is investigated by means of X-ray diffraction (XRD) measurement the average size of which is about 14 nm using Scherrer's relation. Magnetization measurements of the samples are carried out by alternating gradient force magnetometer (AGFM). These results have shown that the arc discharge method is an effective method for preparing magnetic fluids in one step and EG is the effective medium for caring Fe NPs against oxidation. Therefore, the method can pave the way for the synthesis of other NPs such as Fe, Fe-Co, Fe-Pt and iron oxide.

  2. Rheological Characterization of Polysaccharide–Poly(ethylene glycol) Star Copolymer Hydrogels

    PubMed Central

    Yamaguchi, Nori; Chae, Byeong-Seok; Zhang, Le; Kiick, Kristi L.; Furst, Eric M.

    2008-01-01

    Binding interactions between low molecular weight heparin (LMWH) and heparin-binding peptides (HBP) have been applied as a strategy for the assembly of hydrogels that are capable of sequestering growth factors and delivering them in a controlled manner. In this work, the assembly of four-arm star poly(ethylene glycol) (PEG)–LMWH conjugate with PEG–HBP conjugates has been investigated. The interactions between LMWH and the heparin-binding regions of antithrombin III (ATIII) or the heparin interacting protein (HIP) have been characterized via heparin affinity chromatography and surface plasmon resonance (SPR); results indicate that the two peptides have slightly different affinities for heparin and LMWH, and bind LMWH with micromolar affinity. Solutions of the PEG–LMWH and of mixtures of the PEG–LMWH and PEG–HBP were characterized via both bulk rheology and laser tweezer microrheology. Interestingly, solutions of PEG–LMWH (2.5 wt % in PBS) form hydrogels in the absence of PEG–ATIII or PEG–HIP, with storage moduli, determined via bulk rheological measurements, in excess of the loss moduli over frequencies of 0.1–100 Hz. The addition of PEG–ATIII or PEG–HIP increases the moduli in direct proportion to the number of cross-links introduced. Characterization of the hydrogels via microrheology shows the gel microstructure is composed of polymer-rich fibrillar structures surrounded by polymer-depleted buffer. Potential applications of these hydrogels are discussed. PMID:16004430

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

    PubMed

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

    2009-03-03

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

  4. Quick freezing of one-cell mouse embryos using ethylene glycol with sucrose.

    PubMed

    Rayos, A A; Takahashi, Y; Hishinuma, M; Kanagawa, H

    1992-03-01

    One-cell mouse embryos were frozen by direct plunging into liquid nitrogen (LN(2)) vapor after equilibration in 3 M ethylene glycol with 0.25 M sucrose (freezing medium) for 5 to 40 minutes. After thawing, the embryos were cultured in vitro and the effects of the equilibration period and dilution method were examined. No significant difference was observed in the in vitro survival of embryos when 0.5 or 1.0 M sucrose was used for the dilution of the cryoprotectant for each equilibration period. The highest survival rate (67.2%) was obtained when the embryos were equilibrated for 10 minutes, and the cryoprotectant diluted with either 0.5 or 1.0 M sucrose after thawing. Shorter (5 minutes) or prolonged (40 minutes) equilibration of embryos in the freezing medium yielded significantly lower survival rates. Dilution by direct transfer of the frozen-thawed embryos into PB1 resulted in lower survival rates than when 0.5 or 1.0 M sucrose was used. The in vitro development to the blastocyst stage of one-cell mouse embryos frozen after 10 minutes equilibration in the freezing medium and diluted after thawing in 0.5 M sucrose was significantly lower than the control (68.0 vs 92.7%). However, transfer of the blastocysts developing from frozen-thawed one-cell mouse embryos into the uterine horns of the recipients resulted in fetal development and implantation rates similar to the control.

  5. pH-Responsive globular poly(ethylene glycol) for photodynamic tumor therapy.

    PubMed

    Ku, Eun Bi; Lee, Dong Jin; Na, Kun; Choi, Sung-Wook; Youn, Yu Seok; Bae, Soo Kyung; Oh, Kyung Taek; Lee, Eun Seong

    2016-12-01

    In this study, we report the development of extremely small-sized globular poly(ethylene glycol) (gPEG) that can specifically recognize tumor acidic pH. gPEG coupled with chlorin e6 (Ce6, a photosensitizing drug) and 2,3-dimethylmaleic acid (DMA, as a pH-responsive moiety) (gPEG-Ce6-DMA, particle size: 3-4nm in diameter) was easily dispersed in phosphate buffered saline (PBS) without any of the nanoparticle fabrication steps. We observed that gPEG-Ce6-DMA displayed pH-dependent zeta-potential changes due to coupling (at pH 7.4) or decoupling (at pH 6.8-6.0) of DMA. As a result, the uptake of gPEG-Ce6-DMA was significantly increased in tumors at acidic pH, likely due to the decoupling of DMA (backing cationic primary amines). As a result, the preferential cellular uptake of gPEG-Ce6-DMA at acidic pH allowed for a significant enhancement of in vitro/in vivo photodynamic tumor cell ablation under light illumination.

  6. Passive nutrient addition for the biodegradation of ethylene glycol in storm water.

    PubMed

    Safferman, Steven I; Azar, Roger A; Sigler, Stephanie

    2002-01-01

    This laboratory proof-of-concept research examined the feasibility of adding solid, slow-release macronutrients to a biofilm reactor system to achieve the effective biodegradation of a predominately organic polluted storm water. The target scenario was treating ethylene glycol in storm water, representing the runoff of airport deicing and anti-icing fluids. However, the results can also be generalized for any water polluted with a predominately carbonaceous material. The use of a solid, slow-release nutrient source, compared to amending with a soluble solution in proportion to influent flow, would be ideal for storm water applications and other specialized wastewater flows when maintenance requirements and operational support must be minimized. Several commercially available fertilizers were preliminarily examined to determine which had the best potential to provide the required amount of nutrients. A time-released, polymer-coated granular fertilizer was ultimately selected. Based on laboratory studies, it was found that this fertilizer could provide a controllable source of macronutrients that enabled treatment to a similar degree as if the macronutrients had been dissolved in the influent. The only major operational problem was reduced nutrient delivery from the fertilizer after it became coated with a thick biofilm. However, the inherent intermittent nature of storm water production resulting in wet/dry cycles may minimize the development of a thick biofilm.

  7. Thermal conductivity and viscosity measurements of ethylene glycol-based Al2O3 nanofluids

    NASA Astrophysics Data System (ADS)

    Pastoriza-Gallego, María José; Lugo, Luis; Legido, José Luis; Piñeiro, Manuel M.

    2011-12-01

    The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction. The thermal conductivity and viscosity were experimentally determined at temperatures ranging from 283.15 K to 323.15 K using an apparatus based on the hot-wire method and a rotational viscometer, respectively. It has been found that both thermal conductivity and viscosity increase with the concentration of nanoparticles, whereas when the temperature increases the viscosity diminishes and the thermal conductivity rises. Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available. New viscosity experimental data yield values more than twice larger than the base fluid. The influence of particle size on viscosity has been also studied, finding large differences that must be taken into account for any practical application. These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity.

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

    PubMed

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

    2013-12-01

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

  9. Towards stable catalysts for aqueous phase conversion of ethylene glycol for renewable hydrogen.

    PubMed

    Koichumanova, Kamila; Vikla, Anna Kaisa K; de Vlieger, Dennis J M; Seshan, K; Mojet, Barbara L; Lefferts, Leon

    2013-09-01

    Aqueous-phase reforming of ethylene glycol over alumina-supported Pt-based catalysts is reported. Performance of the catalysts is investigated by conducting kinetics and in situ attenuated total reflectance (ATR)-IR spectroscopic analysis. Pt/γ-Al2 O3 is unstable under APR conditions (270 °C, 90 bar) and undergoes phase transformation to boehmite [AlO(OH)]. This conversion of alumina is studied in situ by using ATR-IR spectroscopy; transition into boehmite proceeds even at milder conditions (210 °C, 40 bar). Pt/γ-Al2 O3 deactivates irreversibly because the Pt surface area decreases owing to an increasing metal particle size and coverage with boehmite. However, Pt supported on boehmite itself shows stable activity. Surprisingly, the rate of formation of hydrogen per Pt surface atom is significantly higher on boehmite compared to an alumina-supported catalyst. This observation seems correlated to both increased concentration of surface OH groups as well as to enhanced oxidation of Pt when comparing Pt/γ-Al2 O3 with Pt/AlO(OH). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    PubMed Central

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

    2015-01-01

    Half mustard (CEES) and nitrogen mustard (NM) are commonly used surrogates and vesicant analogs of the chemical warfare agent sulfur mustard. In the current study, in situ forming poly(ethylene glycol) (PEG)-based doxycycline hydrogels are developed and evaluated for their wound healing efficacy in CEES and NM exposed rabbit corneas in organ culture. The hydrogels, characterized by UV-Vis spectrophotometry, rheometry, and swelling kinetics, showed that the hydrogels are optically transparent, have good mechanical strength and a relatively low degree of swelling (<7%). In vitro doxycycline release from the hydrogel disks (0.25% w/v) was found to be biphasic with release half times of ~12 and 72 h, respectively, with 80–100% released over a 7-day period. Permeation of doxycycline through vesicant wounded corneas was found to be 2.5 to 3.4 fold higher than non-wounded corneas. Histology and immunofluorescence studies showed a significant reduction of matrix metalloproteinase-9 (MMP-9) and improved healing of vesicant exposed corneas by doxycycline hydrogels compared to a similar dose of doxycycline delivered in phosphate buffered saline (PBS, pH 7.4). In conclusion, the current studies demonstrate that the doxycycline-PEG hydrogels accelerate corneal wound healing after vesicant injury offering a therapeutic option for ocular mustard injuries. PMID:19853296

  11. Effect of inorganic salts on crystallization of poly(ethylene glycol) in frozen solutions.

    PubMed

    Izutsu, Ken-ichi; Aoyagi, Nobuo

    2005-01-06

    The effect of inorganic salts on eutectic crystallization of poly(ethylene glycol) (PEG) 1500-20,000 in frozen solution was studied to model the polymer and inorganic salt interaction in freeze-dried formulations. Thermal analysis of an aqueous PEG 3000 solution showed a eutectic PEG crystallization exotherm at approximately -47 degrees C and a subsequent PEG crystal melting endotherm at -14.9 degrees C. Addition of sodium chloride prevented the PEG crystallization in the freeze-concentrated solution surrounding ice crystals. Higher concentration NaCl was required to retain higher molecular weight PEG in the amorphous state. Various inorganic salts prevented the PEG crystallization to varying degrees depending mainly on the position of the anion in the Hofmeister's lyotropic series. Some salting-in and 'intermediate' salts (NaSCN, NaI, NaBr, NaCl, LiCl, KCl, and RbCl) inhibited the crystallization of PEG 7500 in frozen solutions. On the other hand, salting-out salts (NaH2PO4, Na2HPO4, Na2SO4, and NaF) did not show an apparent effect on the PEG crystallization. Some salting-out salts induced PEG crystallization in PEG and sucrose combination frozen solutions. The varying abilities of salts to prevent the PEG crystallization in frozen solutions strongly suggested that the solutes had different degrees of miscibility in the freeze-concentrates.

  12. Implementation of tetra-poly(ethylene glycol) hydrogel with high mechanical strength into microfluidic device technology

    PubMed Central

    Takehara, Hiroaki; Nagaoka, Akira; Noguchi, Jun; Akagi, Takanori; Sakai, Takamasa; Chung, Ung-il; Kasai, Haruo; Ichiki, Takanori

    2013-01-01

    Hydrogels have several excellent characteristics suitable for biomedical use such as softness, biological inertness and solute permeability. Hence, integrating hydrogels into microfluidic devices is a promising approach for providing additional functions such as biocompatibility and porosity, to microfluidic devices. However, the poor mechanical strength of hydrogels has severely limited device design and fabrication. A tetra-poly(ethylene glycol) (tetra-PEG) hydrogel synthesized recently has high mechanical strength and is expected to overcome such a limitation. In this research, we have comprehensively studied the implementation of tetra-PEG gel into microfluidic device technology. First, the fabrication of tetra-PEG gel/PDMS hybrid microchannels was established by developing a simple and robust bonding technique. Second, some fundamental features of tetra-PEG gel/PDMS hybrid microchannels, particularly fluid flow and mass transfer, were studied. Finally, to demonstrate the unique application of tetra-PEG-gel-integrated microfluidic devices, the generation of patterned chemical modulation with the maximum concentration gradient: 10% per 20 μm in a hydrogel was performed. The techniques developed in this study are expected to provide fundamental and beneficial methods of developing various microfluidic devices for life science and biomedical applications. PMID:24404072

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

    PubMed Central

    2015-01-01

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

  14. Lubricin is expressed in chondrocytes derived from osteoarthritic cartilage encapsulated in poly (ethylene glycol) diacrylate scaffold

    PubMed Central

    Musumeci, G.; Loreto, C.; Carnazza, M.L.; Coppolino, F.; Cardile, V.; Leonardi, R.

    2011-01-01

    Osteoarthritis (OA) is characterized by degenerative changes within joints that involved quantitative and/or qualitative alterations of cartilage and synovial fluid lubricin, a mucinous glycoprotein secreted by synovial fibroblasts and chondrocytes. Modern therapeutic methods, including tissue-engineering techniques, have been used to treat mechanical damage of the articular cartilage but to date there is no specific and effective treatment. This study aimed at investigating lubricin immunohistochemical expression in cartilage explant from normal and OA patients and in cartilage constructions formed by Poly (ethylene glycol) (PEG) based hydrogels (PEG-DA) encapsulated OA chondrocytes. The expression levels of lubricin were studied by immunohistochemistry: i) in tissue explanted from OA and normal human cartilage; ii) in chondrocytes encapsulated in hydrogel PEGDA from OA and normal human cartilage. Moreover, immunocytochemical and western blot analysis were performed in monolayer cells from OA and normal cartilage. The results showed an increased expression of lubricin in explanted tissue and in monolayer cells from normal cartilage, and a decreased expression of lubricin in OA cartilage. The chondrocytes from OA cartilage after 5 weeks of culture in hydrogels (PEGDA) showed an increased expression of lubricin compared with the control cartilage. The present study demonstrated that OA chondrocytes encapsulated in PEGDA, grown in the scaffold and were able to restore lubricin biosynthesis. Thus our results suggest the possibility of applying autologous cell transplantation in conjunction with scaffold materials for repairing cartilage lesions in patients with OA to reduce at least the progression of the disease. PMID:22073377

  15. 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

  16. Effect of the Physicochemical Properties of Poly(Ethylene Glycol) Brushes on their Binding to Cells

    PubMed Central

    McNamee, Cathy E.; Yamamoto, Shinpei; Higashitani, Ko

    2007-01-01

    We investigated the effect of the number of oxyethylene groups (polymer molecular weight) and the interchain binding and/or entanglements of methoxy-terminated-poly(ethylene glycol) (m-PEG) brushes on their ability to adsorb to living malignant melanoma B16F10 cells. We used the atomic force microscope colloid probe method to determine the adhering ability of the m-PEG brushes to the cells, as the magnitude of the adhesion force between the m-PEG modified particles and the living cells in a physiological buffer was related to the binding strength of the m-PEGs to the cells. We saw that m-PEG brushes (average molecular weights 330, 1900, and 5000 g/mol), which were chemically attached to silica particles, may bind to living B16F10 cells. The binding of m-PEGs to living B16F10 cells increased as the oxyethylene chain length of the m-PEGs increased, if the m-PEGs had a low degree of entanglements or little inter-m-PEG chain binding. A high degree of entanglements or interchain binding decreased the ability of an m-PEG chain to bind to a living cell. The effect of m-PEG (molecular weight 1900 g/mol) being present at cell surfaces for 24 h was also seen not to induce the death of the cells or affect their growth. PMID:17434943

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

    PubMed

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

    2016-01-01

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

  18. FTIR spectroscopic study of poly(ethylene glycol)-nifedipine dispersion stability in different relative humidities.

    PubMed

    Iqbal, Waleed S; Chan, K L

    2015-01-01

    Solid dispersion has shown to be a promising formulation strategy to enhance dissolution for hydrophobic drugs. However, solid dispersions are often thermodynamically unstable, there is a continuous interest in studying their stabilities. In this study, attenuated total reflectance Fourier transform infrared (ATR-FTIR) was used to compare the amount of crystalline nifedipine formed in different formula of poly(ethylene glycol) (PEG)-nifedipine solid dispersions when exposed at various relative humidities (RHs) for 2 h at 40°C. The ratio of the crystalline nifedipine band and an internal reference band in the out of plane δ(C-H) region has been used to indicate the relative degree of drug crystallisation in a sample. A band ratio of ∼0.05 and 0.5 was respectively indicative of a fully amorphous or crystallised drug in the formula. Results show that increasing the RH generally increases the amount of crystalline nifedipine. Formulations with low (5%, w/w) nifedipine concentration in higher molecular weight PEG were found to be better at resisting crystallisation. Deliquescence of the 10% nifedipine in PEG 4000 was observed at 77% and 100% RH with a reduction in crystalline nifedipine. All 5% (w/w) nifedipine samples were stable at RH below 77%. Crystallisation of nifedipine occurred at all RH when drug loading was increased to 10% (w/w). © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  19. 3D cell entrapment in crosslinked thiolated gelatin-poly(ethylene glycol) diacrylate hydrogels

    PubMed Central

    Fu, Yao; Xu, Kedi; Zheng, Xiaoxiang; Giacomin, A. Jeffrey; Mix, Adam W.; Kao, Weiyuan John

    2012-01-01

    The combined use of natural ECM components and synthetic materials offers an attractive alternative to fabricate hydrogel-based tissue engineering scaffolds to study cell-matrix interactions in three-dimensions (3D). A facile method was developed to modify gelatin with cysteine via a bifunctional PEG linker, thus introducing free thiol groups to gelatin chains. A covalently crosslinked gelatin hydrogel was fabricated using thiolated gelatin and poly(ethylene glycol) diacrylate (PEGdA) via thiol-ene reaction. Unmodified gelatin was physically incorporated in a PEGdA-only matrix for comparison. We sought to understand the effect of crosslinking modality on hydrogel physicochemical properties and the impact on 3D cell entrapment. Compared to physically incorporated gelatin hydrogels, covalently crosslinked gelatin hydrogels displayed higher maximum weight swelling ratio (Qmax), higher water content, significantly lower cumulative gelatin dissolution up to 7 days, and lower gel stiffness. Furthermore, fibroblasts encapsulated within covalently crosslinked gelatin hydrogels showed extensive cytoplasmic spreading and the formation of cellular networks over 28 days. In contrast, fibroblasts encapsulated in the physically incorporated gelatin hydrogels remained spheroidal. Hence, crosslinking ECM protein with synthetic matrix creates a stable scaffold with tunable mechanical properties and with long-term cell anchorage points, thus supporting cell attachment and growth in the 3D environment. PMID:21955690

  20. Poly(ethylene glycol) hydrogels with cell cleavable groups for autonomous cell delivery

    PubMed Central

    Kar, Mrityunjoy; Shih, Yu-Ru Vernon; Velez, Daniel Ortiz; Cabrales, Pedro; Varghese, Shyni

    2015-01-01

    Cell-responsive hydrogels hold tremendous potential as cell delivery devices in regenerative medicine. In this study, we developed a hydrogel-based cell delivery vehicle, in which the encapsulated cell cargo control its own release from the vehicle in a protease-independent manner. Specifically, we have synthesized a modified poly(ethylene glycol) (PEG) hydrogel that undergoes degradation responding to cell-secreted molecules by incorporating disulfide moieties onto the backbone of the hydrogel precursor. Our results show the disulfide-modified PEG hydrogels disintegrate seamlessly into solution in presence of cells without any external stimuli. The rate of hydrogel degradation, which ranges from hours to months, is found to be dependent upon the type of encapsulated cells, cell number, and fraction of disulfide moieties present in the hydrogel backbone. The differentiation potential of human mesenchymal stem cells released from the hydrogels is maintained in vitro. The in vivo analysis of these cell-laden hydrogels, through a dorsal window chamber and intramuscular implantation, demonstrated autonomous release of cells to the host environment. The hydrogel-mediated implantation of cells resulted in higher cell retention within the host tissue when compared to that without a biomaterial support. Biomaterials that function as a shield to protect cell cargos and assist their delivery in response to signals from the encapsulated cells could have a wide utility in cell transplantation and could improve the therapeutic outcomes of cell-based therapies. PMID:26606444

  1. Insulin/poly(ethylene glycol)-block-poly(L-lysine) Complexes: Physicochemical Properties and Protein Encapsulation.

    PubMed

    Pippa, Natassa; Kalinova, Radostina; Dimitrov, Ivaylo; Pispas, Stergios; Demetzos, Costas

    2015-06-04

    Insulin (INS) was encapsulated into complexes with poly(ethylene glycol)-block-poly(L-lysine) (PEG-b-PLys), which is a polypeptide-based block copolymer (a neutral-cationic block polyelectrolyte). The particular cationic-neutral block copolymer can complex INS molecules in aqueous media via electrostatic interactions. Light-scattering techniques are used to study the complexation process and structure of the hybrid nanoparticles in a series of buffers, as a function of protein concentration. The physicochemical and structural characteristics of the complexes depend on the ionic strength of the aqueous medium, while the concentration of PEG-b-PLys was constant through the series of solutions. As INS concentration increased the size distribution of the complexes decreased, especially at the highest ionic strength. The size/structure of complexes diluted in biological medium indicated that the copolymer imparts stealth properties and colloidal and biological stability to the complexes, features that could in turn affect the clearance properties in vivo. Therefore, these studies could be a rational roadmap for designing the optimum complexes/effective nanocarriers for proteins and peptides.

  2. Fabrication of dopamine modified polylactide-poly(ethylene glycol) scaffolds with adjustable properties.

    PubMed

    Shen, Jiali; Shi, Dongjian; Shi, Chang; Li, Xiaojie; Chen, Mingqing

    2017-12-01

    Bio-based polymers have been widely used to be as scaffolds for repairing the bone defects. However, the polymer scaffolds are generally lack of bioactivity and cell recognition site. Seeking effective ways to improve the bioactivity and interaction between materials and tissue or cells is clinically important for long-term performance of bone repair materials. In this work, polylactide-b-poly(ethylene glycol)-b-polylactide (PLA-PEG-PLA, PLEL) tri-block copolymers were firstly synthesized by ring-opening polymerization of lactide using PEG with various molecular weights. Inspired by excellent adhesion of dopamine (DA), a facile and effective method was developed to fabricate polydopamine (PDA) and polydopamine/nano-hydroxyapatite (PDA/n-HA) modified PLEL scaffolds by deposition of PDA and PDA/n-HA coating. The surface structure, degradation rates and mineralization of the modified PLEL scaffolds were investigated, and obviously improved after immobilization of PDA and PDA/n-HA coatings. Moreover, the biocompatible results showed a significant increase in cells viability and adhesion. Therefore, the surface modification with PDA and PDA/n-HA could not only adjust the properties of scaffolds, but also reinforce the interfacial adhesion between the PLEL and cells.

  3. Toxicity review of ethylene glycol monomethyl ether and its acetate ester.

    PubMed

    Johanson, G

    2000-05-01

    Ethylene glycol monomethyl ether (EGME) and its acetate ester (EGMEA) are highly flammable, colorless, moderately volatile liquids with very good solubility properties. They are used in paints, lacquers, stains, inks and surface coatings, silk-screen printing, photographic and photo lithographic processes, for example, in the semiconductor industry, textile and leather finishing, production of food-contact plastics, and as an antiicing additive in hydraulic fluids and jet fuel. EGME and EGMEA are efficiently absorbed by inhalation as well as via dermal penetration. Dermal absorption may contribute substantially to the total uptake following skin contact with liquids or vapours containing EGME or EGMEA. EGMEA is rapidly converted to EGME in the body and the two substances are equally toxic in animals. Therefore, the two substances should be considered as equally hazardous to man. Effects on peripheral blood, testes, and sperm have been reported at occupational exposure levels ranging between 0.4 and 10 ppm EGME in air, and with additional, possibly substantial, dermal exposure. Severe malformations and disturbed hematopoiesis have been linked with exposure to EGME and EGMEA at unknown, probably high, levels. Embryonic deaths in monkeys and impaired spermatogenesis in rabbits have been reported after daily oral doses of 12 and 25 mg per kg body weight, respectively. In several studies, increased frequency of spontaneous abortions, disturbed menstrual cycle, and subfertility have been demonstrated in women working in the semiconductor industry. The contribution of EGME in relation to other exposure factors in the semiconductor industry is unclear.

  4. Poly(ethylene glycol) hydrogels with cell cleavable groups for autonomous cell delivery.

    PubMed

    Kar, Mrityunjoy; Vernon Shih, Yu-Ru; Velez, Daniel Ortiz; Cabrales, Pedro; Varghese, Shyni

    2016-01-01

    Cell-responsive hydrogels hold tremendous potential as cell delivery devices in regenerative medicine. In this study, we developed a hydrogel-based cell delivery vehicle, in which the encapsulated cell cargo control its own release from the vehicle in a protease-independent manner. Specifically, we have synthesized a modified poly(ethylene glycol) (PEG) hydrogel that undergoes degradation responding to cell-secreted molecules by incorporating disulfide moieties onto the backbone of the hydrogel precursor. Our results show the disulfide-modified PEG hydrogels disintegrate seamlessly into solution in presence of cells without any external stimuli. The rate of hydrogel degradation, which ranges from hours to months, is found to be dependent upon the type of encapsulated cells, cell number, and fraction of disulfide moieties present in the hydrogel backbone. The differentiation potential of human mesenchymal stem cells released from the hydrogels is maintained in vitro. The in vivo analysis of these cell-laden hydrogels, through a dorsal window chamber and intramuscular implantation, demonstrated autonomous release of cells to the host environment. The hydrogel-mediated implantation of cells resulted in higher cell retention within the host tissue when compared to that without a biomaterial support. Biomaterials that function as a shield to protect cell cargos and assist their delivery in response to signals from the encapsulated cells could have a wide utility in cell transplantation and could improve the therapeutic outcomes of cell-based therapies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Preparation of poly(ethylene glycol) protected nanoparticles with variable bioconjugate ligand density.

    PubMed

    Gindy, Marian E; Ji, Shengxiang; Hoye, Thomas R; Panagiotopoulos, Athanassios Z; Prud'homme, Robert K

    2008-10-01

    Maleimide-functional poly(ethylene glycol)-b-poly(epsilon-caprolactone) nanoparticles (NPs) were prepared via the Flash NanoPrecipitation technique. Subsequent reaction with a model ligand, bovine serum albumin (BSA), was conducted using thiol-maleimide conjugation. Reaction of up to 22% of NP surface maleimide-PEG tethers was obtained, with the percent conversion being essentially independent of the ratio of maleimide-PEG to methyl-PEG over the range 30-100%, respectively. At the highest surface coverage, BSA is calculated to essentially cover the NP surface area. Reaction parameters (reaction order and docking constant) describing the extent of ligand conjugation were determined. The reaction order is applicable to the conjugation of ligands presenting free thiol functionalities, while the value of the docking constant is ligand-dependent and accounts for physical and dynamic properties of the ligand-PEG interaction. Jointly, the particle formation process, using block copolymer-directed kinetically controlled assembly and surface functionalization represent a versatile new platform for the preparation of bioconjugated NPs with accurate control of ligand density and minimal processing steps.

  6. Synthesis of uniform polyaniline nanorods with the assistance of ethylene glycol

    NASA Astrophysics Data System (ADS)

    Qiu, Wei; Ma, Li; Gan, Mengyu; Yan, Jun; Zeng, Shu; Li, Zhitao; Bai, Youqian

    2014-04-01

    The uniform polyaniline (PANI) nanorods were prepared by the chemical method with the assistance of ethylene glycol (EG) medium. The morphology and structure of the PANI nanorods were characterized by SEM, TEM, FTIR, and UV-vis technique, and the effects of stirring on the morphology, structure, electrical conductivity, and electrochemical behavior of PANI were investigated. The results showed that as-synthesized PANI can be facilely dispersed in water and ethanol to form colloids. During the reaction, the H-bonding between molecules of PANI and EG plays a key role for the one-dimensional. In the presence of stirring, uniform PANI nanorods with diameters of 50-80 nm and length up to 400-800 nm can be obtained, and the aspect ratio is about 4. While in the absence of stirring, the aspect ratio of nanorods increases to more than 10, the diameter and length are 20-60 nm and 0.2-1 μm, respectively. In addition, the stirring can result in a higher doping level, conductivity, and degree of oxidation. Based on these results, a possible formation mechanism of PANI nanostructures is presented.

  7. Exploring Antiurolithic Effects of Gokshuradi Polyherbal Ayurvedic Formulation in Ethylene-Glycol-Induced Urolithic Rats

    PubMed Central

    Shirfule, Amol L.; Racharla, Venkatesh; Qadri, S. S. Y. H.; Khandare, Arjun L.

    2013-01-01

    Gokshuradi Yog (GY) is a polyherbal ayurvedic formulation used traditionally for several decades in India for the treatment of urolithiasis. The aim of the present study was to determine the underlying mechanism of GY action in the management of calcium oxalate urolithiasis. The effect of Gokshuradi polyherbal aqueous extracts (GPAEs) was studied on various biochemical parameters involved in calcium oxalate formation by employing in vitro and in vivo methods. GPAE exhibited significant antioxidant activity against 1, 1-diphenyl-2-picrylhydrazyl free radical and inhibited lipid peroxidation in the in vitro experiments. The rat model of urolithiasis induced by 0.75% ethylene glycol (EG) and 1% ammonium chloride (AC) in water caused polyuria, weight loss, impairment of renal function, and oxidative stress and decreased antioxidant enzyme activities in untreated control groups. However, GPAE- (25, 50, and 100 mg/kg) treated groups caused diuresis accompanied by a saluretic effect and revealed significant increase in antioxidant enzyme activities along with decreased oxalate synthesizing biochemical parameters at higher doses. This study revealed the antiurolithic effect of GPAE mediated possibly through inhibiting biochemical parameters involved in calcium oxalate formation, along with its diuretic and antioxidant effects, hence supporting its use in the treatment of calcium oxalate urolithiasis. PMID:23554833

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

    PubMed

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

    2002-04-23

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

  9. Chitosan hollow nanospheres fabricated from biodegradable poly-D,L-lactide-poly(ethylene glycol) nanoparticle templates.

    PubMed

    Wang, Weijia; Luo, Chao; Shao, Shijun; Zhou, Shaobing

    2010-11-01

    Biodegradable chitosan hollow nanospheres were fabricated by employing uniform poly-D,L-lactide-poly(ethylene glycol) (PELA) nanoparticles as templates. Chitosan was adsorbed onto the surface of PELA nanoparticle templates through the electrostatic interaction between the sulphuric acid groups from sodium dodecyl sulfate (SDS) on the templates and the amino groups of the chitosan. Subsequently, the core-coated structure of chitosan-PELA nanospheres was obtained with the adsorbed chitosan layer being further crosslinked with glutaraldehyde. After the removal of the templates, PELA cores, chitosan hollow nanospheres were achieved. The mean size and size distribution of these nanospheres were measured with dynamic light scattering. The hollow structure was identified by transmission electron microscopy, atomic force microscopy and laser confocal scanning microscope. The antitumor drug model, adriamycin hydrochloride, was adsorbed on/into the chitosan hollow nanospheres. The drug release behaviors were investigated in phosphate buffered solution (PBS) at pH 7.4 and acetate buffered solution (ABS) at pH 4.5, respectively, at 37°C, and in vitro tumor cell growth inhibition assay was also evaluated. The biodegradable hollow nanospheres possess great potential applications in nanomedicine. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Drying and Storage Effects on Poly(ethylene glycol) Hydrogel Mechanical Properties and Bioactivity

    PubMed Central

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

    2014-01-01

    Hydrogels based on poly(ethylene glycol) (PEG) are increasingly used in biomedical applications due to the ability to control cell-material interactions by tuning hydrogel physical and biological properties. Evaluation of stability after drying and storage are critical in creating an off-the-shelf biomaterial that functions in vivo according to original specifications. However, there has not been a study that systematically investigates the effects of different drying conditions and hydrogel compositional variables. In the first part of this study, PEG-diacrylate hydrogels underwent common processing procedures (vacuum-drying, lyophilizing, hydrating then vacuum-drying) and the effect of this processing on the mechanical properties and swelling ratios was measured. Significant changes in compressive modulus, tensile modulus, and swelling ratio only occurred for select processed hydrogels. No consistent trends were observed after processing for any of the formulations tested. The effect of storage conditions on cell adhesion and spreading on collagen- and streptococcal collagen-like protein (Scl2-2)-PEG-diacrylamide hydrogels was then evaluated to characterize bioactivity retention after storage. Dry storage conditions preserved bioactivity after 6 weeks of storage; whereas, storage in PBS significantly reduced bioactivity. This loss of bioactivity was attributed to ester hydrolysis of the protein linker, acrylate-PEG-N-hydroxysuccinimide. These studies demonstrate that these processing methods and dry storage conditions may be used to prepare bioactive PEG hydrogel scaffolds with recoverable functionality after storage. PMID:24123725

  11. Treatment of patients with ethylene glycol or methanol poisoning: focus on fomepizole

    PubMed Central

    Mégarbane, Bruno

    2010-01-01

    Ethylene glycol (EG) and methanol are responsible for life-threatening poisonings. Fomepizole, a potent alcohol dehydrogenase (ADH) inhibitor, is an efficient and safe antidote that prevents or reduces toxic EG and methanol metabolism. Although no study has compared its efficacy with ethanol, fomepizole is recommended as a first-line antidote. Treatment should be started as soon as possible, based on history and initial findings including anion gap metabolic acidosis, while awaiting measurement of alcohol concentration. Administration is easy (15 mg/kg-loading dose, either intravenously or orally, independent of alcohol concentration, followed by intermittent 10 mg/kg-doses every 12 hours until alcohol concentrations are <30 mg/dL). There is no need to monitor fomepizole concentrations. Administered early, fomepizole prevents EG-related renal failure and methanol-related visual and neurological injuries. When administered prior to the onset of significant acidosis or organ injury, fomepizole may obviate the need for hemodialysis. When dialysis is indicated, 1 mg/kg/h-continuous infusion should be provided to compensate for its elimination. Side-effects are rarely serious and with a lower occurrence than ethanol. Fomepizole is contraindicated in case of allergy to pyrazoles. It is both efficacious and safe in the pediatric population, but is not recommended during pregnancy. In conclusion, fomepizole is an effective and safe first-line antidote for EG and methanol intoxications. PMID:27147840

  12. Beyond poly(ethylene glycol): linear polyglycerol as a multifunctional polyether for biomedical and pharmaceutical applications.

    PubMed

    Thomas, Anja; Müller, Sophie S; Frey, Holger

    2014-06-09

    Polyglycerols (sometimes also called "polyglycidols") represent a class of highly biocompatible and multihydroxy-functional polymers that may be considered as a multifunctional analogue of poly(ethylene glycol) (PEG). Various architectures based on a polyglycerol scaffold are feasible depending on the monomer employed. While polymerization of glycidol leads to hyperbranched polyglycerols, the precisely defined linear analogue is obtained by using suitably protected glycidol as a monomer, followed by removal of the protective group in a postpolymerization step. This review summarizes the properties and synthetic approaches toward linear polyglycerols (linPG), which are at present mainly based on the application of ethoxyethyl glycidyl ether (EEGE) as an acetal-protected glycidol derivative. Particular emphasis is placed on the manifold functionalization strategies including, e.g., the synthesis of end-functional linPGs or multiheterofunctional modifications at the polyether backbone. Potential applications like bioconjugation and utilization as a component in degradable biomaterials or for diagnostics, in which polyglycerol acts as a promising PEG substitute are discussed. In the last section, the important role of linear polyglycerol as a macroinitiator or as a highly hydrophilic segment in block co- or terpolymers is highlighted.

  13. 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.

  14. Kolaviron protects against ethylene glycol monoethyl ether-induced toxicity in boar spermatozoa.

    PubMed

    Adedara, I A; Farombi, E O

    2014-05-01

    This study investigated the ameliorative effects of kolaviron (a biflavonoid from the seed of Garcinia kola) and vitamin C on ethylene glycol monoethyl ether (EGEE)-induced oxidative damage in boar spermatozoa in vitro. EGEE (1.0 mm) was incubated with boar spermatozoa for 3 h with or without either kolaviron (50 and 100 μm) or vitamin C (1.0 mm). Spermatozoa parameters were determined hourly during the incubation period, whereas aminotransferases and alkaline phosphatase activities and oxidative stress indices were assessed after the incubation period. Results showed a time-dependent decline in spermatozoa motility and viability with significant elevation in total abnormalities in EGEE-treated spermatozoa. Exposure to EGEE resulted in significant increase in aminotransferases, alkaline phosphatase and superoxide dismutase (SOD) activities, whereas it markedly decreased glutathione (GSH) level, catalase (CAT) and glutathione S-transferase (GST) activities with concomitant increase in hydrogen peroxide (H2 O2 ) and malondialdehyde (MDA) levels. Pre-treatment of spermatozoa with kolaviron or vitamin C significantly decreased H2 O2 and MDA levels, improved spermatozoa characteristics and ameliorated oxidative damage in EGEE-treated spermatozoa. Taken together, EGEE exhibited its spermatotoxicity via induction of oxidative stress. The protective effects by kolaviron and vitamin C against EGEE-induced oxidative damage may be due to their intrinsic antioxidative potentials.

  15. A molecular dynamics simulations study on ethylene glycol-water mixtures in mesoporous silica

    NASA Astrophysics Data System (ADS)

    Schmitz, Rebecca; Müller, Niels; Ullmann, Svenja; Vogel, Michael

    2016-09-01

    We perform molecular dynamics simulations to investigate structural and dynamical properties of ethylene glycol-water (EG-WA) mixtures in mesoporous silica. To obtain comprehensive insights into the dependence of liquid behaviors on the confinement features, we exploit that straightforward modification of the force field parameters allows us to vary the properties of the hydrogen-bond network of the confined liquid, we alter the polarity of the silica surface, and we consider amorphous as well as crystalline matrices. It is observed that the confinement induces a micro-phase separation in the liquid, which qualitatively depends on the properties of both liquid and matrix so that EG or WA molecules may be preferentially adsorbed at the silica surface. Furthermore, it is found that the confinement strongly affects the liquid dynamics. Largely independent of the polarity and structure of the matrix, structural relaxation is about a factor of 104 slower at the pore wall than in the pore center. Moreover, the non-Arrhenius temperature dependence of the bulk mixture turns into an Arrhenius behavior of the confined mixture so that the spatial restriction can slow down or speed up the structural relaxation, depending on temperature.

  16. Dielectric Properties of Boron Nitride-Ethylene Glycol (BN-EG) Nanofluids

    NASA Astrophysics Data System (ADS)

    Fal, Jacek; Cholewa, Marian; Gizowska, Magdalena; Witek, Adam; ŻyŁa, GaweŁ

    2017-02-01

    This paper presents the results of experimental investigation of the dielectric properties of ethylene glycol (EG) with various load of boron nitride (BN) nanoparticles. The nanofuids were prepared by using a two-step method on the basis of commercially available BN nanoparticles. The measurements were carried out using the Concept 80 System (NOVOCONTROL Technologies GmbH & Co. KG, Montabaur, Germany) in a frequency range from 10 Hz to 10 MHz and temperatures from 278.15 K to 328.15 K. The frequency-dependent real (ɛ ^' }) and imaginary (ɛ ^' ' }) parts of the complex permittivity (ɛ ^*) and the alternating current (AC) conductivity are presented. Also, the effect of temperature and mass concentrations on the dielectric properties of BN-EG nanofluids are demonstrated. The results show that the most significant increase can be achieved for 20 wt.% of BN nanoparticles at 283.15 K and 288.15 K, that is eleven times larger than in the case of pure EG.

  17. Covalent enzyme immobilization by poly(ethylene glycol) diglycidyl ether (PEGDE) for microelectrode biosensor preparation.

    PubMed

    Vasylieva, Natalia; Barnych, Bogdan; Meiller, Anne; Maucler, Caroline; Pollegioni, Loredano; Lin, Jian-Sheng; Barbier, Daniel; Marinesco, Stéphane

    2011-06-15

    Poly(ethylene glycol) diglycidyl ether (PEGDE) is widely used as an additive for cross-linking polymers bearing amine, hydroxyl, or carboxyl groups. However, the idea of using PEGDE alone for immobilizing proteins on biosensors has never been thoroughly explored. We report the successful fabrication of microelectrode biosensors based on glucose oxidase, d-amino acid oxidase, and glutamate oxidase immobilized using PEGDE. We found that biosensors made with PEGDE exhibited high sensitivity and a response time on the order of seconds, which is sufficient for observing biological processes in vivo. The enzymatic activity on these biosensors was highly stable over several months when they were stored at 4 °C, and over at least 3d at 37 °C. Glucose microelectrode biosensors implanted in the central nervous system of anesthetized rats reliably monitored changes in brain glucose levels induced by sequential administration of insulin and glucose. PEGDE provides a simple, low cost, non-toxic alternative for the preparation of in vivo microelectrode biosensors.

  18. Preparation and characterization of novel poly(ethylene glycol) paclitaxel derivatives.

    PubMed

    Arpicco, Silvia; Stella, Barbara; Schiavon, Oddone; Milla, Paola; Zonari, Daniele; Cattel, Luigi

    2013-10-01

    Paclitaxel has been found to be very effective against several human cancers; one of the major problems with its use is its poor solubility, which makes necessary its solubilization with excipients that can determine allergic reactions often severe. The aim of this study is to develop highly water-soluble prodrugs of paclitaxel. For this purpose we prepared a series of new paclitaxel-poly(ethylene glycol) (PEG) conjugates that were characterized and evaluated for their in vitro stability and cytotoxicity. In particular, in order to modulate the release of paclitaxel from prodrugs, we prepared different compounds introducing PEG in the drug C2' and/or C7 positions via ester or carbamate linkage. The conjugates were obtained in high purity and good yield. The carbamate prodrugs were highly stable in different media, while the compounds obtained linking PEG at C2' position through an ester bond showed lower stability. Finally, the cytotoxic activity of the conjugates was evaluated on two cancer cell lines and the results showed that all the derivatives had a reduced cytotoxicity compared to that of paclitaxel.

  19. Improving the Dielectric Properties of Ethylene-Glycol Alkanethiol Self-Assembled Monolayers

    PubMed Central

    2014-01-01

    Self-assembled monolayers (SAMs) can be formed at the interface between solids and fluids, and are often used to modify the surface properties of the solid. One of the most widely employed SAM systems is exploiting thiol-gold chemistry, which, together with alkane-chain-based molecules, provides a reliable way of SAM formation to modify the surface properties of electrodes. Oligo ethylene-glycol (OEG) terminated alkanethiol monolayers have shown excellent antifouling properties and have been used extensively for the coating of biosensor electrodes to minimize nonspecific binding. Here, we report the investigation of the dielectric properties of COOH-capped OEG monolayers and demonstrate a strategy to improve the dielectric properties significantly by mixing the OEG SAM with small concentrations of 11-mercaptoundecanol (MUD). The monolayer properties and composition were characterized by means of impedance spectroscopy, water contact angle, ellipsometry and X-ray photoelectron spectroscopy. An equivalent circuit model is proposed to interpret the EIS data and to determine the conductivity of the monolayer. We find that for increasing MUD concentrations up to about 5% the resistivity of the SAM steadily increases, which together with a considerable decrease of the phase of the impedance, demonstrates significantly improved dielectric properties of the monolayer. Such monolayers will find widespread use in applications which depend critically on good dielectric properties such as capacitive biosensor. PMID:24447311

  20. Synthesis and Characterization of Tunable Poly(Ethylene Glycol): Gelatin Methacrylate Composite Hydrogels

    PubMed Central

    Hutson, Che B.; Nichol, Jason W.; Aubin, Hug; Bae, Hojae; Yamanlar, Seda; Al-Haque, Shahed; Koshy, Sandeep T.

    2011-01-01

    Poly(ethylene glycol) (PEG) hydrogels are popular for cell culture and tissue-engineering applications because they are nontoxic and exhibit favorable hydration and nutrient transport properties. However, cells cannot adhere to, remodel, proliferate within, or degrade PEG hydrogels. Methacrylated gelatin (GelMA), derived from denatured collagen, yields an enzymatically degradable, photocrosslinkable hydrogel that cells can degrade, adhere to and spread within. To combine the desirable features of each of these materials we synthesized PEG-GelMA composite hydrogels, hypothesizing that copolymerization would enable adjustable cell binding, mechanical, and degradation properties. The addition of GelMA to PEG resulted in a composite hydrogel that exhibited tunable mechanical and biological profiles. Adding GelMA (5%–15% w/v) to PEG (5% and 10% w/v) proportionally increased fibroblast surface binding and spreading as compared to PEG hydrogels (p<0.05). Encapsulated fibroblasts were also able to form 3D cellular networks 7 days after photoencapsulation only within composite hydrogels as compared to PEG alone. Additionally, PEG-GelMA hydrogels displayed tunable enzymatic degradation and stiffness profiles. PEG-GelMA composite hydrogels show great promise as tunable, cell-responsive hydrogels for 3D cell culture and regenerative medicine applications. PMID:21306293

  1. Bioactive Modification of Poly(ethylene glycol) Hydrogels for Tissue Engineering

    PubMed Central

    Zhu, Junmin

    2010-01-01

    In this review, we explore different approaches for introducing bioactivity into poly(ethylene glycol) (PEG) hydrogels. Hydrogels are excellent scaffolding materials for repairing and regenerating a variety of tissues because they can provide a highly swollen three-dimensional (3D) environment similar to soft tissues. Synthetic hydrogels like PEG-based hydrogels have advantages over natural hydrogels, such as the ability for photopolymerization, adjustable mechanical properties, and easy control of scaffold architecture and chemical compositions. However, PEG hydrogels alone cannot provide an ideal environment to support cell adhesion and tissue formation due to their bio-inert nature. The natural extracellular matrix (ECM) has been an attractive model for the design and fabrication of bioactive scaffolds for tissue engineering. ECM-mimetic modification of PEG hydrogels has emerged as an important strategy to modulate specific cellular responses. To tether ECM-derived bioactive molecules (BMs) to PEG hydrogels, various strategies have been developed for the incorporation of key ECM biofunctions, such as specific cell adhesion, proteolytic degradation, and signal molecule-binding. A number of cell types have been immobilized on bioactive PEG hydrogels to provide fundamental knowledge of cell/scaffold interactions. This review addresses the recent progress in material designs and fabrication approaches leading to the development of bioactive hydrogels as tissue engineering scaffolds. PMID:20303169

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

    PubMed

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

    2014-09-01

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

  3. A novel rapamycin-polymer conjugate based on a new poly(ethylene glycol) multiblock copolymer

    PubMed Central

    Tai, Wanyi; Chen, Zhijin; Barve, Ashutosh; Peng, Zhonghua; Cheng, Kun

    2014-01-01

    Purpose Rapamycin has demonstrated potent anti-tumor activity in preclinical and clinical studies. However, the clinical development of its formulations was hampered due to its poor solubility and undesirable distribution in vivo. Chemical modification of rapamycin presents an opportunity for overcoming the obstacles and improving its therapeutic index. The objective of this study is to develop a drug-polymer conjugate to increase the solubility and cellular uptake of rapamycin. Methods We developed the rapamycin-polymer conjugate using a novel, linear, poly(ethylene glycol) (PEG) based multiblock copolymer. Cytotoxicity and cellular uptake of the rapamycin-polymer conjugate were evaluated in various cancer cells. Results The rapamycin-polymer conjugate provides enhanced solubility in water compared with free rapamycin and shows profound activity against a panel of human cancer cell lines. The rapamycin-polymer conjugate also presents high drug loading capacity (wt% ~ 26%) when GlyGlyGly is used as a linker. Cellular uptake of the conjugate was confirmed by confocal microscopy examination of PC-3 cells that were cultured in the presence of FITC-labled polymer (FITC-polymer). Conclusion This study suggests that the rapamycin-polymer conjugate is a novel anti-cancer agent that may provide an attractive strategy for treatment of a wide variety of tumors. PMID:24072263

  4. Crosslinking density influences chondrocyte metabolism in dynamically loaded photocrosslinked poly(ethylene glycol) hydrogels.

    PubMed

    Bryant, Stephanie J; Chowdhury, Tina T; Lee, David A; Bader, Dan L; Anseth, Kristi S

    2004-03-01

    In approaches to tissue engineer articular cartilage, an important consideration for in situ forming cell carriers is the impact of mechanical loading on the cell composite structure and function. Photopolymerized hydrogel scaffolds based on poly(ethylene glycol) (PEG) may be synthesized with a range of crosslinking densities and corresponding macroscopic properties. This study tests the hypothesis that changes in the hydrogel crosslinking density influences the metabolic response of encapsulated chondrocytes to an applied load. PEG hydrogels were formulated with two crosslinking densities that resulted in gel compressive moduli ranging from 60 to 670 kPa. When chondrocytes were encapsulated in these PEG gels, an increase in crosslinking density resulted in an inhibition in cell proliferation and proteoglycan synthesis. Moreover, when the gels were dynamically loaded for 48 h in unconfined compression with compressive strains oscillating from 0 to 15% at a frequency of 1 Hz, cell proliferation and proteoglycan synthesis were affected in a crosslinking-density-dependent manner. Cell proliferation was inhibited in both crosslinked gels, but was greater in the highly crosslinked gel. In contrast, dynamic loading did not influence proteoglycan synthesis in the loosely crosslinked gel, but a marked decrease in proteoglycan production was observed in the highly crosslinked gel. In summary, changes in PEG hydrogel properties greatly affect how chondrocytes respond to an applied dynamic load.

  5. An in situ infrared spectroscopic investigation of the pyrolysis of ethylene glycol encapsulated in silica sodalite.

    SciTech Connect

    Maroni, V. A.; Epperson, S. J.; Chemical Engineering; Univ. of Tulsa

    2001-11-29

    The thermal stability and pyrolysis of ethylene glycol (EG) encapsulated in the sodalite cages of all-silica sodalite were studied by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and transmission infrared spectroscopy. Evidence for the presence of encapsulated CO2 formed as a result of partial decomposition of EG molecules was observed starting at about 600 K. Complete, irreversible pyrolysis of the EG occurred between 675 and 775 K. After treatment at 775 K, the CO2 remained encapsulated in the sodalite framework, even though there were spectroscopic indications that the pyrolysis caused a disordering of the sodalite framework. There appeared to be a temperature dependence of the conformational interactions of the EG O---H groups up to 600 K, which was mainly manifested as a weakening of intramolecular hydrogen bonding. The only detectable encapsulated products of the EG decomposition in an inert (N2 or Ar) environment were CO2 and a carbonaceous (coke- or soot-like) residue. There was no evidence of other encapsulated products, such as CO, H2, H2O, or light hydrocarbons.

  6. Fabrication and characterization of plasma-polymerized poly(ethylene glycol) film with superior biocompatibility.

    PubMed

    Choi, Changrok; Hwang, Inseong; Cho, Young-Lai; Han, Sang Y; Jo, Dong H; Jung, Donggeun; Moon, Dae W; Kim, Eun J; Jeon, Chang S; Kim, Jeong H; Chung, Taek D; Lee, Tae G

    2013-02-01

    A newly fabricated plasma-polymerized poly(ethylene glycol) (PP-PEG) film shows extremely low toxicity, low fouling, good durability, and chemical similarity to typical PEG polymers, enabling live cell patterning as well as various bioapplications using bioincompatible materials. The PP-PEG film can be overlaid on any materials via the capacitively coupled plasma chemical vapor deposition (CCP-CVD) method using nontoxic PEG200 as a precursor. The biocompatibility of the PP-PEG-coated surface is confirmed by whole blood flow experiments where no thrombi and less serum protein adsorption are observed when compared with bare glass, polyethylene (PE), and polyethylene terephthalate (PET) surfaces. Furthermore, unlike bare PE films, less fibrosis and inflammation are observed when the PP-PEG-coated PE film is implanted into subcutaneous pockets of mice groin areas. The cell-repellent property of PP-PEG is also verified via patterning of mammalian cells, such as fibroblasts and hippocampal neurons. These results show that our PP-PEG film, generated by the CCP-CVD method, is a biocompatible material that can be considered for broad applications in biomedical and functional materials fields.

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

    PubMed

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

    2014-08-01

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

  8. Interaction of Hyaluronan Binding Peptides with Glycosaminoglycans in Poly(ethylene glycol) Hydrogels

    PubMed Central

    2015-01-01

    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

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

    PubMed

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

    2010-02-01

    Half mustard (CEES) and nitrogen mustard (NM) are commonly used surrogates and vesicant analogs of the chemical warfare agent sulfur mustard. In the current study, in situ forming poly(ethylene glycol) (PEG)-based doxycycline hydrogels are developed and evaluated for their wound healing efficacy in CEES and NM-exposed rabbit corneas in organ culture. The hydrogels, characterized by UV-Vis spectrophotometry, rheometry, and swelling kinetics, showed that the hydrogels are optically transparent, have good mechanical strength and a relatively low degree of swelling (<7%). In vitro doxycycline release from the hydrogel disks (0.25% w/v) was found to be biphasic with release half times of approximately 12 and 72h, respectively, with 80-100% released over a 7-day period. Permeation of doxycycline through vesicant wounded corneas was found to be 2.5 to 3.4 fold higher than non-wounded corneas. Histology and immunofluorescence studies showed a significant reduction of matrix metalloproteinase-9 (MMP-9) and improved healing of vesicant-exposed corneas by doxycycline hydrogels compared to a similar dose of doxycycline delivered in phosphate buffered saline (PBS, pH 7.4). In conclusion, the current studies demonstrate that the doxycycline-PEG hydrogels accelerate corneal wound healing after vesicant injury offering a therapeutic option for ocular mustard injuries.

  10. Immobilization of oriented protein molecules on poly(ethylene glycol)-coated Si(111).

    PubMed

    Cha, Taewoon; Guo, Athena; Jun, Yongseok; Pei, Duanqing; Pei, Duanquing; Zhu, Xiao-Yang

    2004-07-01

    A high-density poly(ethylene glycol) (PEG)-coated Si(111) surface is used for the immobilization of polyhistidine-tagged protein molecules. This process features a number of properties that are highly desirable for protein microarray technology: (i) minimal nonspecific protein adsorption; (ii) highly uniform surface functionality; (iii) controlled protein orientation; and (iv) highly specific immobilization reaction without the need of protein purification. The high-density PEG-coated silicon surface is obtained from the reaction of a multi-arm PEG (mPEG) molecule with a chlorine terminated Si(111) surface to give a mPEG film with thickness of 5.2 nm. Four out of the eight arms on each immobilized mPEG molecule are accessible for linking to the chelating iminodiacetic acid (IDA) groups for the binding of Cu(2+) ions. The resulting Cu(2+)-IDA-mPEG-Si(111) surface is shown to specifically bind 6x histidine-tagged protein molecules, including green fluorescent protein (GFP) and sulfotransferase (ST), but otherwise retains its inertness towards nonspecific protein adsorption. We demonstrate a particular advantage of this strategy: the possibility of protein immobilization without the need of prepurification. Surface concentrations of relevant chemical species are quantitatively characterized at each reaction step by X-ray photoelectron spectroscopy (XPS). This kind of quantitative analysis is essential in tuning surface concentration and chemical environment for optimal sensitivity in probe-target interaction.

  11. Cyclodextrin/poly(ethylene glycol) polypseudorotaxane hydrogels as a promising sustained-release system for lysozyme.

    PubMed

    Higashi, Taishi; Tajima, Anna; Motoyama, Keiichi; Arima, Hidetoshi

    2012-08-01

    In this study, to clarify the utility of polypseudorotaxane (PPRX) hydrogels composed of poly(ethylene glycol) (PEG) and α- or γ-cyclodextrin (α- or γ-CyD) as a sustained-release system for protein drugs, we prepared CyD PPRX hydrogels including lysozyme, and then the release profiles of lysozyme from these hydrogels and the release mechanisms were investigated. The α- and γ-CyD formed PPRX hydrogels by threading onto one PEG chain and two PEG chains, respectively. The formation of α- and γ-CyD PPRX hydrogels including lysozyme was based on physical cross-linking arisen from their columnar structures. The in vitro release rates of lysozyme were markedly decreased by the encapsulation into CyD PPRX hydrogels. In addition, when release data were plotted according to Korsmeyer-Peppas model, the exponent values (n) in the α- and γ-CyD systems had no statistically significant difference, suggesting that these release mechanisms were almost same. In conclusion, these results suggest that α- and γ-CyD PPRX hydrogels possess the potential as a sustained-release system for lysozyme.

  12. Effect of incorporation of ethylene glycol into PEDOT:PSS on electron phonon coupling and conductivity

    SciTech Connect

    Lin, Yow-Jon Ni, Wei-Shih; Lee, Jhe-You

    2015-06-07

    The effect of incorporation of ethylene glycol (EG) into poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on electron phonon coupling and conductivity is investigated. It is shown that the carrier density (N{sub C}) increases significantly and the carrier mobility (μ) increases slightly at 300 K. The increased intensity of the Raman spectrum between 1400 and 1450 cm{sup −1}, following EG treatment (that is, the quinoid-dominated structures of the PEDOT chain), leads to an increase in the number of polarons (bipolarons), which leads to an increase in N{sub C}. In addition, μ in PEDOT:PSS samples with or without EG addition exhibits a strong temperature dependence, which demonstrates the dominance of tunneling (hopping) at low (high) temperatures. The high conductivity of PEDOT:PSS samples with the addition of EG is attributed to the combined effect of the modification of the electron-phonon coupling and the increase in N{sub C} (μ)

  13. Effects of surfactant micelles on viscosity and conductivity of poly(ethylene glycol) solutions

    NASA Astrophysics Data System (ADS)

    Wang, Shun-Cheng; Wei, Tzu-Chien; Chen, Wun-Bin; Tsao, Heng-Kwong

    2004-03-01

    The neutral polymer-micelle interaction is investigated for various surfactants by viscometry and electrical conductometry. In order to exclude the well-known necklace scenario, we consider aqueous solutions of low molecular weight poly(ethylene glycol) (2-20)×103, whose radial size is comparable to or smaller than micelles. The single-tail surfactants consist of anionic, cationic, and nonionic head groups. It is found that the viscosity of the polymer solution may be increased several times by micelles if weak attraction between a polymer segment and a surfactant exists, ɛ

  14. ROLE OF TUNGSTEN IN THE AQUEOUS PHASE HYDRODEOXYGENATION OF ETHYLENE GLYCOL ON TUNGSTATED ZIRCONIA SUPPORTED PALLADIUM

    SciTech Connect

    Marin-Flores, Oscar G.; Karim, Ayman M.; Wang, Yong

    2014-11-15

    The focus of the present work was specifically on the elucidation of the role played by tungsten on the catalytic activity and selectivity of tungstated zirconia supported palladium (Pd-mWZ) for the aqueous phase hydrodeoxygenation (APHDO) of ethylene glycol (EG). Zirconia supported palladium (Pd-mZ) was used as reference. The catalysts were prepared via incipient wet impregnation and characterized using X-ray diffraction (XRD), temperature-programmed reduction (TPR), CO pulse chemisorption, CO-DRIFTS, ammonia temperature-programmed desorption (NH3-TPD) and pyridine adsorption. The presence of W results in larger Pd particles on supported Pd catalysts, i.e., 0.9 and 6.1 nm Pd particles are for Pd-mZ and Pd-mWZ, respectively. For comparison purposes, the activity of the catalytic materials used in this work was obtained using a well-defined set of operating conditions. The catalytic activity measurements show that the overall intrinsic activity of Pd particles on mWZ is 1.9 times higher than on mZ. APHDO process appears to be highly favored on Pd-mWZ whereas Pd-mZ exhibits a higher selectivity for reforming. This difference in terms of selectivity seems to be related to the high concentration of Brønsted acid sites and electron-deficient Pd species present on Pd-mWZ.

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

    PubMed Central

    Lee, Soah; Tong, Xinming

    2016-01-01

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

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

    PubMed

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

    2014-10-08

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

  17. Selective catalytic two-step process for ethylene glycol from carbon monoxide

    PubMed Central

    Dong, Kaiwu; Elangovan, Saravanakumar; Sang, Rui; Spannenberg, Anke; Jackstell, Ralf; Junge, Kathrin; Li, Yuehui; Beller, Matthias

    2016-01-01

    Upgrading C1 chemicals (for example, CO, CO/H2, MeOH and CO2) with C–C bond formation is essential for the synthesis of bulk chemicals. In general, these industrially important processes (for example, Fischer Tropsch) proceed at drastic reaction conditions (>250 °C; high pressure) and suffer from low selectivity, which makes high capital investment necessary and requires additional purifications. Here, a different strategy for the preparation of ethylene glycol (EG) via initial oxidative coupling and subsequent reduction is presented. Separating coupling and reduction steps allows for a completely selective formation of EG (99%) from CO. This two-step catalytic procedure makes use of a Pd-catalysed oxycarbonylation of amines to oxamides at room temperature (RT) and subsequent Ru- or Fe-catalysed hydrogenation to EG. Notably, in the first step the required amines can be efficiently reused. The presented stepwise oxamide-mediated coupling provides the basis for a new strategy for selective upgrading of C1 chemicals. PMID:27377550

  18. Specific Heat Capacity of Physically Confined Ethylene glycol in Nano Pores

    NASA Astrophysics Data System (ADS)

    Amanuel, Samuel; Linthicum, Will

    2013-03-01

    Sensible heat is a cheap and effective means of storing solar energy where energy storage density can be improved by enhancing the specific heat capacity of the heat transfer materials. Formulating composite materials of heat transfer fluids is a mechanism by which the bulk specific heat capacity can be altered and preferably increased. Traditionally, the specific heat capacity of composite material is evaluated from the weighed average of the individual specific heat capacities of the constituents. This, however, does not take into account the effect of interfacial atoms and molecules. The effect of interfacial atoms and molecules becomes increasingly significant when one of the constituents has dimensions in nano meters. In this study, we evaluate the role of interfacial molecules on the specific heat capacity of composite systems. In order to systematically control the interfacial molecules, we have measured the specific heat capacity of ethylene glycol when it is physically confined in nano pores. This work has been supported financially by Union College Faculty Research Fund, NSF-EEC 0939322 and New York State NASA space grant for financial support.

  19. Metabolic engineering of Corynebacterium glutamicum for the de novo production of ethylene glycol from glucose.

    PubMed

    Chen, Zhen; Huang, Jinhai; Wu, Yao; Liu, Dehua

    2016-01-01

    Development of sustainable biological process for the production of bulk chemicals from renewable feedstock is an important goal of white biotechnology. Ethylene glycol (EG) is a large-volume commodity chemical with an annual production of over 20 million tons, and it is currently produced exclusively by petrochemical route. Herein, we report a novel biosynthetic route to produce EG from glucose by the extension of serine synthesis pathway of Corynebacterium glutamicum. The EG synthesis is achieved by the reduction of glycoaldehyde derived from serine. The transformation of serine to glycoaldehyde is catalyzed either by the sequential enzymatic deamination and decarboxylation or by the enzymatic decarboxylation and oxidation. We screened the corresponding enzymes and optimized the production strain by combinatorial optimization and metabolic engineering. The best engineered C. glutamicum strain is able to accumulate 3.5 g/L of EG with the yield of 0.25 mol/mol glucose in batch cultivation. This study lays the basis for developing an efficient biological process for EG production. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  20. Effects of sulpiride and ethylene glycol monomethyl ether on endometrial carcinogenicity in Donryu rats.

    PubMed

    Taketa, Yoshikazu; Inoue, Kaoru; Takahashi, Miwa; Sakamoto, Yohei; Watanabe, Gen; Taya, Kazuyoshi; Yoshida, Midori

    2016-06-01

    Sulpiride and ethylene glycol monomethyl ether (EGME) are known ovarian toxicants that stimulate prolactin (PRL) secretion, resulting in hypertrophy of the corpora lutea and increased progesterone (P4) production. The purpose of the present study was to investigate how the PRL stimulatory agents affected uterine carcinogenesis and to clarify the effects of PRL on endometrial adenocarcinoma progression in rats. Ten-week-old female Donryu rats were treated once with N-ethyl-N'-nitro-N-nitrosoguanidine (20 mg kg(-1) ), followed by treatment with sulpiride (200 ppm) or EGME (1250 ppm) from 11 weeks of age to 12 months of age. Sulpiride treatment inhibited the incidence of uterine adenocarcinoma and precancerous lesions of atypical endometrial hyperplasia, whereas EGME had no effect on uterine carcinogenesis. Sulpiride markedly prevented the onset of persistent estrus throughout the study period, and EGME delayed and inhibited the onset of persistent estrus. Moreover, sulpiride-treated animals showed high PRL and P4 serum levels without changes in the levels of estradiol-17β, low uterine weights and histological luteal cell hypertrophy. EGME did not affect serum PRL and P4 levels. These results suggest that the prolonged low estradiol-17β to P4 ratio accompanied by persistent estrous cycle abnormalities secondary to the luteal stimulatory effects of PRL may explain the inhibitory effects of sulpiride on uterine carcinogenesis in rats. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Complement activation by sulfonated poly(ethylene glycol)-acrylate copolymers through alternative pathway.

    PubMed

    Jang, Hong Seok; Ryu, Kyu Eun; Ahn, Woong Shick; Chun, Heung Jae; Dal Park, Hyung; Park, Ki Dong; Kim, Young Ha

    2006-07-01

    Previously, novel poly(ethylene glycol) (PEG) and sulfonated PEG acrylate (PEG-SO(3)A/OA) copolymers were prepared as coating and/or blending materials for biomedical applications. Surfaces modified with copolymers exhibited increased anti-coagulation properties and decreased plasma adsorption level due to increased hydrophilic properties and reorientation characteristics of PEG/PEG-SO(3)A chains in water phase. As continuation study, anti-complement effects of PEG-SO(3)/OA copolymers were investigated in vitro, and compared with those of low-density polyethylene (LDPE) and PEG/OA. C3 activation by PEG-SO(3)/OA samples was lower than that by PEG/OA samples, which was attributed to decreased surface nucleophile level of samples. PEG-SO(3)/OA samples increased inhibition of Bb production, resulting in decreased C5 activation. Owing to reduced activations of C3 and C5, PEG-SO(3)/OA samples markedly decreased SC5b-9 levels in plasma.

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

    PubMed

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

    2008-04-01

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

  3. Encapsulation of Huh-7 cells within alginate-poly(ethylene glycol) hybrid microspheres.

    PubMed

    Mahou, Redouan; Tran, Nhu Mai; Dufresne, Murielle; Legallais, Cécile; Wandrey, Christine

    2012-01-01

    Novel calcium alginate poly(ethylene glycol) hybrid microspheres (Ca-alg-PEG) were developed and evaluated as potentially suitable materials for cell microencapsulation. Grafting 5-13% of the backbone units of sodium alginate (Na-alg) with α-amine-ω-thiol PEG maintained the gelling capacity in presence of calcium ions, while thiol end groups allowed for preparing chemically crosslinked hydrogel via spontaneous disulfide bond formation. The combination of these two gelling mechanisms yielded Ca-alg-PEG. Human hepatocellular carcinoma cells (Huh-7) were encapsulated in Ca-alg-PEG and calcium alginate beads (Ca-alg), and cultured for 2 weeks under agitation conditions. Immediately after completion of the microencapsulation, the cell viability was 60% and similar in Ca-alg-PEG and Ca-alg. The proliferation of Huh-7 encapsulated in Ca-alg-PEG was slightly higher than in Ca-alg. Accelerated proliferation after 2 weeks was observed for the encapsulation in Ca-alg-PEG. The production of albumin confirmed the functionality of the encapsulated Huh-7 cells. The study confirms the suitability of Ca-alg-PEG and the one-step technology for cell microencapsulation.

  4. Enhanced yield of ethylene glycol production from d-xylose by pathway optimization in Escherichia coli.

    PubMed

    Cabulong, Rhudith B; Valdehuesa, Kris Niño G; Ramos, Kristine Rose M; Nisola, Grace M; Lee, Won-Keun; Lee, Chang Ro; Chung, Wook-Jin

    2017-02-01

    The microbial production of renewable ethylene glycol (EG) has been gaining attention recently due to its growing importance in chemical and polymer industries. EG has been successfully produced biosynthetically from d-xylose through several novel pathways. The first report on EG biosynthesis employed the Dahms pathway in Escherichia coli wherein 71% of the theoretical yield was achieved. This report further improved the EG yield by implementing metabolic engineering strategies. First, d-xylonic acid accumulation was reduced by employing a weak promoter which provided a tighter control over Xdh expression. Second, EG yield was further improved by expressing the YjgB, which was identified as the most suitable aldehyde reductase endogenous to E. coli. Finally, cellular growth, d-xylose consumption, and EG yield were further increased by blocking a competing reaction. The final strain (WTXB) was able to reach up to 98% of the theoretical yield (25% higher as compared to the first study), the highest reported value for EG production from d-xylose. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    PubMed

    Hwang, Yongsung; Sangaj, Nivedita; Varghese, Shyni

    2010-10-01

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

  6. Preparation of poly(ethylene glycol)-attached dendrimers encapsulating photosensitizers for application to photodynamic therapy.

    PubMed

    Kojima, Chie; Toi, Yoko; Harada, Atsushi; Kono, Kenji

    2007-01-01

    Photodynamic therapy (PDT) is a noninvasive treatment of some diseases including cancer. We have developed poly(ethylene glycol) (PEG)-attached dendrimers as a drug-carrier candidate. In this study, we prepared nanocapsules of photosensitizers using PEG-attached dendrimers for application to PDT. Two PEG-attached dendrimers derived from poly(amido amine) (PAMAM) and poly(propylene imine) (PPI) dendrimers (PEG-PAMAM and PEG-PPI) were synthesized, and rose bengal (RB) and protoporphyrin IX (PpIX) were used as photosensitizers. Results showed that fewer PpIX molecules were encapsulated by both PEG-attached dendrimers than RB, but the complexes were more stable under physiological conditions. Furthermore, we demonstrated that PEG-PPI held photosensitizers in a more stable manner than PEG-PAMAM because of their inner hydrophobicity. We described the cytotoxicity of the complexes of photosensitizers induced by light irradiation in vitro. The complex of PpIX with PEG-PPI exhibited efficient cytotoxicity, compared with free PpIX. It was suggested that the cytotoxicity was caused by the high level of singlet oxygen production and the efficient delivery to mitochondria. Our results suggest that these PEG-attached dendrimers are a promising vehicle for PDT.

  7. Ethylene glycol or methanol intoxication: which antidote should be used, fomepizole or ethanol?

    PubMed

    Rietjens, S J; de Lange, D W; Meulenbelt, J

    2014-02-01

    Ethylene glycol (EG) and methanol poisoning can cause life-threatening complications. Toxicity of EG and methanol is related to the production of toxic metabolites by the enzyme alcohol dehydrogenase (ADH), which can lead to metabolic acidosis, renal failure (in EG poisoning), blindness (in methanol poisoning) and death. Therapy consists of general supportive care (e.g. intravenous fluids, correction of electrolytes and acidaemia), the use of antidotes and haemodialysis. Haemodialysis is considered a key element in the treatment of severe EG and methanol intoxication and is aimed at removing both the parent compound and its toxic metabolites, reducing the duration of antidotal treatment and shortening the hospital observation period. Currently, there are two antidotes used to block ADH-mediated metabolism of EG and methanol: ethanol and fomepizole. In this review, the advantages and disadvantages of both antidotes in terms of efficacy, safety and costs are discussed in order to help the physician to decide which antidote is appropriate in a specific clinical setting.

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

    PubMed

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

    2014-06-01

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

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

    PubMed

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

    2008-09-01

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

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

    PubMed

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

    2014-07-20

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

  11. Micropatterning of Poly(Ethylene Glycol) Diacrylate Hydrogels with Biomolecules to Regulate and Guide Endothelial Morphogenesis

    PubMed Central

    Moon, James J.; Hahn, Mariah S.; Kim, Iris; Nsiah, Barbara A.

    2009-01-01

    Angiogenesis, which is morphogenesis undertaken by endothelial cells (ECs) during new blood vessel formation, has been traditionally studied on natural extracellular matrix proteins. In this work, we aimed to regulate and guide angiogenesis on synthetic, bioactive poly(ethylene glycol)-diacrylate (PEGDA) hydrogels. PEGDA hydrogel is intrinsically cell nonadhesive and highly resistant to protein adsorption, allowing a high degree of control over presentation of ligands for cell adhesion and signaling. Since these materials are photopolymerizable, a variety of photolithographic technologies may be applied to spatially control presentation of bioactive ligands. To manipulate EC adhesion, migration, and tubulogenesis, the surface of PEGDA hydrogels was micropatterned with a cell adhesive ligand, Arg-Gly-Asp-Ser (RGDS), in desired concentrations and geometries. ECs cultured on these RGDS patterns reorganized their cell bodies into cord-like structures on 50-μm-wide stripes, but not on wider stripes, suggesting that EC morphogenesis can be regulated by geometrical cues. The cords formed by ECs were reminiscent of capillaries with cells participating in the self-assembly and reorganization into multicellular structures. Further, endothelial cord formation was stimulated on intermediate concentration of RGDS at 20 μg/cm2, whereas it was inhibited at higher concentrations. This work has shown that angiogenic responses can be tightly regulated and guided by micropatterning of bioactive ligands and also demonstrated great potentials of micropatterned PEGDA hydrogels for various applications in tissue engineering, where vascularization prior to implantation is critical. PMID:18803481

  12. Microencapsulation of islets within alginate/poly(ethylene glycol) gels cross-linked via Staudinger ligation

    PubMed Central

    Hall, Kristina K.; Gattás-Asfura, Kerim M.; Stabler, Cherie L.

    2010-01-01

    Functionalized alginate and PEG polymers were used to generate covalently linked alginate-PEG (XAlgPEG) microbeads of high stability. The cell-compatible Staudinger ligation scheme was used to chemoselectively cross-link phosphine-terminated poly(ethylene glycol) (PEG) to azide-functionalized alginate, resulting in XAlgPEG hydrogels. XAlgPEG microbeads were formed by co-incubation of the two polymers, followed by ionic cross-linking of the alginate using barium ions. The enhanced stability and gel properties of the resulting XAlgPEG microbeads, as well as the compatibility of these polymers for the encapsulation of islets and beta cells lines, were investigated. Our data show that XAlgPEG microbeads exhibit superior resistance to osmotic swelling compared to traditional barium cross-linked alginate (Ba-Alg) beads, with a 5-fold reduction in observed swelling, as well as resistance to dissolution via chelation solution. Diffusion and porosity studies found XAlgPEG beads to exhibit properties comparable to standard Ba-Alg. Our data found XAlgPEG microbeads to be highly cell compatible with insulinoma cell lines, as well as rat and human pancreatic islets, where the viability and functional assessment of cells within XAlgPEG were comparable to Ba-Alg controls. The remarkable improved stability, as well as demonstrated cellular compatibility, of XAlgPEG hydrogels makes them an appealing option for a wide variety of tissue engineering applications. PMID:20654745

  13. Injectable and Photopolymerizable Tissue-Engineered Auricular Cartilage Using Poly(Ethylene Glycol) Dimethacrylate Copolymer Hydrogels

    PubMed Central

    Papadopoulos, Anestis; Bichara, David A.; Zhao, Xing; Ibusuki, Shinichi; Anseth, Kristi S.; Yaremchuk, Michael J.

    2011-01-01

    In this study we investigated the histological, biochemical, and integrative features of the neocartilage using swine auricular chondrocytes photoencapsulated into two poly(ethylene glycol) dimethacrylate (PEGDM) copolymer hydrogels of a different degradation profile: degradable (PEG-4,5LA-DM) and nondegradable (PEGDM) macromers in molar ratios of 60:40 and 70:30. Integration of the engineered tissue with existing native cartilage was examined using an articular cartilaginous ring model. Experimental group samples (total n = 96) were implanted subcutaneously into nude mice and harvested at 6, 12, and 18 weeks. Nonimplanted constructs (total n = 16) were used as controls for quantification of DNA, glycosaminoglycan, and hydroxyproline. Histologically, neocartilage resembled both the cellular population and composition of the extracellular matrix of the native swine auricular cartilage. DNA content demonstrated that the photoencapsulated chondrocytes were capable of survival and proliferation over time. Both glycosaminoglycan and hydroxyproline contents appeared higher in the neotissue, which was supported by less degradable PEGDM hydrogel. Integration of neocartilage with surrounding native cartilage improved with time, resulting in the development of tight integration interface. PEGDM copolymer hydrogels can support in vivo chondrogenesis by photoencapsulating auricular chondrocytes. PMID:20695772

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

    PubMed

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

    2016-09-01

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

  15. Antiurolithiatic effect of lithocare against ethylene glycol-induced urolithiasis in Wistar rats

    PubMed Central

    Lulat, Sumaiya I.; Yadav, Yogesh Chand; Balaraman, R.; Maheshwari, Rajesh

    2016-01-01

    Aim: This study is aimed to investigate the protective effect of Lithocare (LC) (a polyherbal formulation) against ethylene glycol (EG) induced urolithiasis in Wistar rats. Materials and Methods: The protective effect of LC (400 and 800 mg/kg) was evaluated using EG-induced urolithiasis in rats. Results: Administration of EG in drinking water resulted in hyperoxaluria, hypocalcemia as well as an increased renal excretion of phosphate. Supplementation with LC significantly reduced the urinary calcium, oxalate, and phosphate excretion dose-dependently. There was a significant reduction in the levels of calcium, oxalate as well as a number of calcium oxalate crystals deposits in the kidney tissue of rats administered with LC in EG-treated rats. There was a significant reduction in creatinine, urea, uric acid, and blood urea nitrogen when LC was administered in EG-treated rats. Conclusions: From this study, it was concluded that the supplementation of LC protected EG-induced urolithiasis as it reduced the growth of urinary stones. The mechanism underlying this effect might be due to its antioxidant, diuretic, and reduction in stone-forming constituents. PMID:26997728

  16. Doxorubicin conjugate of poly(ethylene glycol)-block-polyphosphoester for cancer therapy.

    PubMed

    Sun, Chun-Yang; Dou, Shuang; Du, Jin-Zhi; Yang, Xian-Zhu; Li, Ya-Ping; Wang, Jun

    2014-02-01

    Polyphosphoesters with repeating phosphoester linkages in the backbone can be easily functionalized, are biodegradable and potentially biocompatible, and may be potential candidates as polymer carriers of drug conjugates. Here, the efficacy of a polyphosphoester drug conjugate as an anticancer agent in vivo is assessed for the first time. With controlled synthesis, doxorubicin conjugated to poly(ethylene glycol)-block-polyphosphoester (PPEH-DOX) via labile hydrazone bonds form spherical nanoparticles in aqueous solution with an average diameter of ≈60 nm. These nanoparticles are effectively internalized by MDA-MB-231 breast cancer cells and release the conjugated doxorubicin in response to the intracellular pH of endosomes and lysosomes, resulting in significant antiproliferative activity in cancer cells. Compared with free doxorubicin injection, PPEH-DOX injection exhibits much longer circulation behavior in the plasma of mice and leads to enhanced drug accumulation in tumor cells. In an MDA-MB-231 xenograft murine model, inhibition of tumor growth with systemic delivery of PPEH-DOX nanoparticles is more pronounced compared with free doxorubicin injection, suggesting the potential of polyphosphoesters as carriers of drug conjugates in cancer therapy.

  17. Efficient dehalogenation of automobile shredder residue in NaOH/ethylene glycol using a ball mill.

    PubMed

    Kameda, Tomohito; Fukuda, Yuuzou; Park, Kye-Sung; Grause, Guido; Yoshioka, Toshiaki

    2009-01-01

    We investigated the effectiveness of sodium hydroxide/ethylene glycol (NaOH/EG) for dehalogenation of automobile shredder residue (ASR) using a ball mill. Efficient dehalogenation was achieved at atmospheric pressure by combining the use of EG (196 degrees C b.p.) as a replacement solvent for NaOH with ball milling, which improved contact between ASR and OH(-) in solution. Moderate NaOH concentrations and increased ball mill rotation speeds produced high dechlorination that was not significantly affected by the weight ratio of ASR to EG. NaOH/EG dechlorination increased with temperature with an apparent activation energy of 50 kJ mol(-1) confirming that the reaction proceeded under chemical reaction control. The modified shrinking-core model was appropriate to explain the dechlorination process. Low chloro levels in our NaOH/EG-treated ASR suggested that this material could be used for feedstock recycling and the wet process may be applicable for dehalogenation of other important waste streams.

  18. Adsorption of hydrophobically end-capped poly(ethylene glycol) on cellulose.

    PubMed

    Holappa, Susanna; Kontturi, Katri S; Salminen, Arto; Seppälä, Jukka; Laine, Janne

    2013-11-12

    Adsorption of poly(ethylene glycol), hydrophobically end-capped with octadecenylsuccinic anhydride (OSA-PEG-OSA), on an ultrathin film of cellulose has been studied by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM). Normally, PEG does not adsorb on cellulosic surfaces, but the use of the telechelic hydrophobic modification was found to promote adsorption. The influence of the conformation of the polymer in solution prior to adsorption and the subsequent properties of the adsorbed layer were investigated. The adsorption experiments were done at concentrations below and above the critical association concentration. The adsorption of OSA-PEG-OSA on cellulose was observed to occur in four distinct stages. Because of the amphiphilic nature of cellulose, further adsorption experiments were performed on hydrophobic (polystyrene) and hydrophilic (silica) model substrates to illuminate the contribution of hydrophobic and hydrophilic factors in the adsorption phenomenon. As expected, the kinetics and the mechanism of adsorption were strongly dependent on the chemical composition of the substrate.

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

    PubMed Central

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

    2006-01-01

    Micelles from the mixture of poly(ethylene glycol)-phosphatidyl ethanolamine conjugate (PEG-PE) and D-α-tocopheryl polyetheyene glycol 1000 succinate (TPGS) were prepared loaded with the poorly soluble anticancer drug camptothecin (CPT). The solubilization of CPT by the mixed micelles was more efficient than with earlier described micelles made of PEG-PE alone. CPT-loaded mixed micelles were stable upon storage and dilution and firmly retained the incorporated drug. The cytotoxicity of the CPT-loaded mixed micelles against various cancer cells in vitro was remarkably higher than that of the free drug. PEG-PE/TPGS mixed micelles may serve as pharmaceutical nanocarriers with improved solubilization capacity for poorly soluble drugs. PMID:16242875

  20. Antioxidants inhibition of high plasma androgenic markers in the pathogenesis of ethylene glycol (EG)-induced nephrolithiasis in Wistar rats.

    PubMed

    Naghii, Mohammad Reza; Mofid, Mahmood; Hedayati, Mehdi; Khalagi, Kazem

    2014-04-01

    The association between serum gonadal steroids and urolithiasis in males received only limited attention. Calcium oxalate urolithiasis is induced by administration of ethylene glycol in drinking water. It appears that the administration of natural antioxidants has been used to protect against nephrolithiasis in human and experimental animals. The purpose is to study the potential role of antioxidants as inhibitors of high plasma androgenic markers or hyperandrogenicity in the pathogenesis of ethylene glycol-induced nephrolithiasis in Wistar rats. Male Wistar rats were studied in 4-week period. Group 1 (control) was fed a standard commercial diet. Group 2 received the same diet with 0.5 % of ethylene glycol. Group 3 received EG plus the diet and water added with antioxidant nutrients and lime juice as the dietary source of citrate. Group 4 and Group 5 were treated similar to Group 2 and Group 3 with 0.75 % of ethylene glycol. For antioxidant supplementation, the standard diet enriched with 4,000.0 μg vitamin E and 1,500.0 IU vitamin A for each rat per day added to the diet once a week, and provided daily with 5.0 mg vitamin C, 400.0 μg vitamin B6, 20.0 μg selenium, 12.0 mg zinc, and 2.0 mg boron for each rat per day in their drinking water. After treatment period, collection of blood was performed and kidneys were removed and used for histopathological examination. The results based on various assays, measuring size of crystal deposition, and histological examinations showed that high concentration of androgens acts as promoter for the formation of renal calculi due to ethylene glycol consumption and the inhibitory role of antioxidant complex in the formation of renal calculi disease. Data revealed that the size and the mean number of crystal deposits determined in EG 0.75 % treated groups (G4) were significantly higher than the EG-treated groups, added with antioxidant nutrients and lime juice (G5). The mean concentration of androgens in Group 4 increased after