• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.524-536
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• 1994

Chitosan is known to be a good biocompatible natural polymer. Polyethyleneglycol monomethacrylates(PEGM) were grafted onto chitosan and their reaction conditions and properties of the graft polymers obtained were estimated. Using ceric ammonium nitrate(CAN) as the initiator, the optimum condition for graft polymerization was determined amount of the initiator and monomer concentrations and reaction time. Grafting yields such as total conversion, the percentage of grafting and the efficiency of grafting were calculated and examined the optimum reaction condition for high grafting yields. The percentage of grafting and total conversion were maximum at condition that the concentration of initiator was $4{\sim}5{\times}10^{-3}M$, the concentration of monomer was 0.5~0.6M, the reaction time was 2~3 hours and the reaction temperature was about $40^{\circ}C$. Thermal characteristics, solubility for chitosan solvents and inherent viscosity of synthesized graft copolymers were investigated. In high initiator concentration, characteristics of chitosan were greatly diminshed. In case of inherent viscosities, chitosan-g-PE-90 was 2.81 dl/g, chitosan-g-PE-200, 3.01dl/g and chitosan-g-PE-350, 4.93dl/g. And a tendency of viscosity increase depending on the length of ethylene oxide residue was confirmed. Degree of swelling, tensile strength, elongation of membrane prepared from graft copolymers were determined. Properties of graft copolymers were affected by percentage of grafting and length of ethylene oxides residue in polyethylene glycol monomethacrylates. Tensile strength, elongation and degree of swelling of graft copolymers were remarkably improved than chitosan. As percentage of grafting increased, the amount of drug permeation was also increased.

• Journal of Pharmaceutical Investigation
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• v.21 no.1
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• pp.11-22
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• 1991

The purpose of this study was for the enhancement of dissolution rate of ketoprofen. The solid dispersions composed of ketoprofen(KP) and polyethylene glycol(PEG) 4000 or 6000 were prepared by fusion method at various ratios of KP to PEG (0.5 : 10, 1 : 10, 2 : 10, 3 : 10 and 4 : 10(w/w)) and their physical mixtures were also prepared at the above ratios. Dissolution tests, X-ray diffraction study and differential scanning calorimetry study were carried out. It was found that the dissolution rates of solid dispersion and physical mixture at any ratio of the two components discribed above were greater than that of the pure ketoprofen. X-ray diffraction studies of ketoprofen suggested that less than 1 to 10 ratio of ketoprofen to PEG4000 (or 6000) was required to dispersion amorphous state in the carrier. In addition, the studies of DSC showed that ketoprofen had a sharp endothermic peak at $94^{\circ}C$ but not for the solid dispersion at the same temperature.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.288-295
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• 1992

The reduction of nitrobenzene by triirondodecacarbonyl over phase transfer catalysts was investigated. The phase transfer catalysts showed a good yield of aniline at room temperature. Benzyltriethylammonium chloride, tricaprylmethyl ammonium chloride, 18-crown-6 and polyethyleneglycol-400 were good phase transfer catalysts in this reaction. The effect of reaction temperature, concentration of sodium hydroxide and organic solvents on the reaction rate and yield of aniline were studied in this work.

• Mycobiology
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• v.34 no.2
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• pp.73-78
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• 2006

Inter-specific hybridization between Pleurotus pulmonarius and P. florida was attempted through PEG-induced protoplast fusion to select a fusant. The protocol for protoplast release, regeneration and fusion in these two Pleurotus species was standardized using the variables controlling the process. The mixture of mycolytic enzymes, i.e. commercial cellulase, crude chitinase and pectinase, KCl (0.6 M) as osmotic stabilizer, pH 6 of the phosphate buffer and an incubation time of 3 hours resulted in the maximum release of protoplasts from 3-day-old mycelia of P. florida ($5.3{\sim}5.75{\times}10^{7}$ protoplasts/g) and P. pulmonarius ($5.6{\sim}6{\times}10^{7}$ protoplasts/g). The isolated protoplasts of P. florida regenerated mycelium with 3.3% regeneration efficiency while P. pulmonarius showed 4.1% efficiency of regeneration. Polyethyleneglycol (PEG)-induced fusion of protoplasts of these two species resulted in 0.28% fusion frequency. The fusant produced fruiting bodies on paddy straw but required a lower temperature of crop running ($24{\pm}2^{\circ}C$) than its parents which could fruit at $28{\pm}2^{\circ}C$. The stable fusant strain was selected by testing for the selected biochemical markers i.e. Carbendazim tolerance and utilization of the lignin degradation product, vanillin.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.11
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• pp.985-993
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• 2006

An experiment to find out the removal mechanism of PEG(polyethyleneglycol) by using UV-enhanced $O_2$ GPC (gas phase cleaning) at low substrate temperature below $200^{\circ}C$ was executed under various process conditions, such as substrate temperature, UV exposure, and $O_2$ gas. The possibility of using $UV/O_2$ GPC as a low-temperature in-situ cleaning tool for organic removal was confirmed by the removal of a PEG film with a thickness of about 200 nm within 150 sec at a substrate temperature of $200^{\circ}C$. Synergistic effects by combining photo-dissociation and photo oxidation can only remove the entire PEG film without residues within experimental splits. In $UV/O_2$ GPC with substrate temperatures higher than the glass transition temperature, the substantial increase in the PEG removal rate can be explained by surface-wave formation. The photo-dissociation of PEG film by UV exposure results in the formation of end aldehyde by dissociation of back-bone chain and direct decomposition of light molecules. The role of oxygen is forming peroxide radicals and/or terminating the dis-proportionation reaction by forming peroxide.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.309-314
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• 1985

Autoxotrophic mutants of a cellulolytic baterium Cellulomonas sp. CS 1-1 were grown at $30^{\circ}C$ for 6hr using a complete medium containing 0.5M sucrose and for another 90 min after addition of 0.3 U/ml penicillin G, and were protoplasted by 0.2mg/ml lysozyme for 2hr. Prototrophic recombinants were obtained at the rates of $10^{-3}$ to $10^{-5}$by fusing the protoplasts in the presence of 40% polyethyleneglycol3350. Nystatin could be used to eliminate fungal contamination during the regeneration of the plotaplasts.

• Journal of Pharmaceutical Investigation
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• v.38 no.1
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• pp.15-21
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• 2008

Liposomes as one of the efficient drug carriers have some shortcomings such as their short circulation time, fast clearance from human body by reticuloendothelial system (RES) and limited intracellular uptake to target cell. In this study, polyethylenglycol (PEG)-incorporated cationic liposomes were prepared by ionic complexation of positively charged liposomes with carboxylated polyethyleneglycol (mPEG-COOH). The cationic liposomes had approximately $98.6{\pm}1.0nm$ of mean particle diameter and $42.8{\pm}0.8mV$ of zeta potential value. The PEG-incorporated cationic liposomes had $110.1{\pm}1.2nm$ of mean particle diameter with an increase of about 10 nm compared to the cationic liposomes. Zeta potential value of them was $12.9{\pm}0.6mV$ indicating 30mV decrease of cationic charge compared to the cationic liposomes. The amount of PEG which was incorporated onto the cationic liposomes was assayed by using picrate assay method and the incorporation efficiency was $58.4{\pm}1.1%$. Loading efficiency of model drug, doxorubicin, into cationic liposomes or PEG-incorporated cationic liposomes was about $96.0{\pm}0.7%$. Results of intracellular uptake which were evaluated by flow cytometry analysis of doxorubicin loaded liposomes showed that intracellular uptake of PEG-incorporated cationic liposomes was higher than the cationic liposomes or DSPE-mPEG liposomes. In addition, cytotoxicity of PEG-incorporated cationic liposomes was comparable to cationic liposomes. Consequently, the PEG-incorporated cationic liposomes of which surface was incorporated with PEG by ionic complex may be applicable as anticancer drug carriers that can increase therapeutic efficacy.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.930-934
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• 1998

The modified poly(ethylene terephthalate) (PET) was synthesized by copolymerizing dimethyl terephthalate with ethylene glycol, polyethyleneglycol, and dodecylbenzene sulfonate as a surfactant. After characterization of viscosity, color, and contant angle, hydrophilic characteristics of the modified PET depending on additives was discussed.

• YAKHAK HOEJI
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• v.31 no.1
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• pp.42-44
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• 1987

Ziperol, anti-tussive, is considerably bitter. Therefore, it is necessary to mitigate the bitterness in ziperol syrup for children. In this experiment, it was attempted to mitigate the bitterness of zipeprol by means of polymers such as $\beta$-cyclodextrin, arabic gum, HPMC(hydroxypropyl methylcellulose), PEG 2000(polyethyleneglycol 2000), PVP(polyvinylpyrrolidone). Caffeine was used as the reference standard of bitterness. In the result of this experiment, $\beta$-cyclodextrin, would mitigate the bitterness of zipeprol more largely than any other polymers. Arabic gum was the second choice which would mitigate the bitterness of zipeprol.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.299.2-300
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• 2003

Various bupivacaine-Ioaded microspheres were prepared with poly (d,l-Iactide) (PLA) by solvent extraction method. The internal solution of polymer(PLA R104) and drug in glacial acetic acid was introduced into the external phase of polyvinylpyrrolidone (PVP K-30) in polyethyleneglycol (PEG), and emulsified to be an oil-in-oil (o/o) emulsion. The o/o emulsion was poured to the buffer solution. (omitted)