• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.269-273
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• 2001

This study presents a new formulation method for improving DNA transfection effi-ciency using a fusogenic peptide and polyethylene glycol-grafted polyethylenimine. Succinimidyls succinate polyethylene glycol (PEG-SSA) was conjugated with polyethylenimine(PEL). PEL is well known for a good endosomal escaping and DNA condensign agent. The positively charged syn-thetic fusogenic peptide, KALA was coated on the negatively charged PEG-g-PEI/DNA and PEI/DNA complexes. The KALA/PEI/ DNA complexes exhibited aggregation behavior at higher KALA coating amount with an effective diameter of around 1,000 nm. However, the LALA/PEG-g-PEI/DNA complexes were 100-300 nm in size with a surface zeta-potential (ζ)value of about +20mV. The conjugated PEG molecules suppressed any KALA-mediated inter-particle aggregation, and thereby improved the transfection efficiency, Consequently, the transfection efficiency of the KALA/PEG-g-PEI/DNA complexes was obtained by utilizing both the fusogenic activity of KALA and the steric repulsion effect of PEC.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.485-489
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• 2017

Polyethylene terephthalate (PET) has been widely applied in polymers and packaging industries to produce synthetic fibers, films, drink bottles or food containers. Therefore, it has become one of the major plastic wastes. In this article, glycolysis known as one of the main methods in PET chemical recycling was investigated using a glycol to break down the polymer into a monomer. Glycolysis of PET and ethylene glycol was performed in a micro-tubing reactor under various conditions. The effect of glycolysis conditions on the product distribution was investigated at experimental conditions of the EG/PET ratio of 1~4, the reaction time of 15~90 min and the reaction temperature of $250{\sim}325^{\circ}C$ with Mn and Cu catalysts. The highest yield of bis (2-hydroxyethyl) terephthalate monomer (BHET) was obtained as 89.46 wt% under the condition of the reaction temperature of $300^{\circ}C$ and the time of 30 min using 10 wt% $Cu/{\gamma}-Al_2O_3$ catalyst, with the PET and ethylene glycol ratio of 1 : 2.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.8-13
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• 2012

The experiments have been performed to obtain zinc complex compound with smaller particle size, which is used as a charge control agent in manufacturing toner. Metallic salts and polyhydric alcohols have been studied to investigate their effects on the formation of different sizes of zinc complex-compound particle. Reactants such as zinc chloride and 3,5-di-tert-butyl salicylic acid have been used to form the complex compound. Polyethylene glycol (PEG-300), glycerin and ethylene glycol have been added into the zinc chloride solution beforehand to lower the reaction rate in the formation of zinc complex-compound. Zirconium (IV) oxychloride octahydrate has been mixed in the zinc chloride solution beforehand to restrain crystals from growing. When PEG-300 and zirconium (IV) oxychloride octahydrate are used to lower the reaction rate and to restrain the particle size from growing, the average particle size of zinc complex compound decreases from 5.28 to 1.84 ${\mu}m$, which is 34.9% of 5.28 ${\mu}m$.

• Polymer(Korea)
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• v.32 no.4
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• pp.305-312
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• 2008

A novel TPC-PEG-TPC with active end-groups was obtained from the end-groups of polyethylene glycol (PEG) modified by terephthaloyl chloride (TPC). These active end-groups can link up with a rare earth ion, which is a luminescent center of a rare earth fluorescent complex. Complexes of Eu-PEG with novel ligands (TPC-PEG-PTC) were synthesized by the coordination of the active reactant (as the first ligand) and phenanthroline (as the second ligand) with $Eu^{3+}$.IR, $^1H$-NMR, element analysis, DSC, WAXD, fluorescent spectroscopy, TGA, and SEM were used to characterize the structure and properties of these complexes. The results showed that this type of complex is a heat storage material with the phase change character of polyethylene glycol (PEG) and the luminescent properties of europium. There was no thermal decomposition of the complex of Eu-PEG until $300^{\circ}C$. SEM showed that the complex of Eu-PEG can be dispersed in PE.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.419-427
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• 1996

To solubilize practically insoluble biphenyl dimethyl dicarboxylate (DDB), which has been used for the treatment of chronic hepatitis as tablets or hard capsules, the solubilities of DDB in various hydrophilic, oily and hydrocarbon vehicles, and aqueous surfactant solutions were measured by high performance liquid chromatography. It was found that, among the vehicles studied, polyethylene glycol (PEG) 300 revealed the best solvency, and the solubility reached 17.6 mg/ml at 37$^{\circ}C$. The addition of glycyrrhizic acid ammonium salt (GAA) to DDB-PEG 300 solution (5-20 mg/g) inhibited the formation of precipitates, and at the concentration of 10 mg/g, any precipitaction was not observed even after 2 years at 4$^{\circ}C$. Furthermore, GAA markedly enhanced the permeation of DDB through the rabbit duodenal mucosa in a concentration dependent manner. The addition of copolyvidone (ca. 1.0%) to DDB-GAA-PEG 300 system (1 : 0.5 97.5 w/w) was most effective in preventing the considerable precipitation of DDB-PEG 300 solution (7.5 mg/750 mg) when mixed with water of 300-900 ml at 37$^{\circ}C$. GAA showed a synergistic effect in the prevention of precipitate formation. This finding suggests that this DDB formulation may form less precipitation when DDB soft capsules disintegrate and diffuse into the gastrointestinal fluid, resulting in improving the bioavailability Dissolution rate of DDB (7.5 mg) from sort elastic capsules of DDB-GAA-PEG 300 system was rapid. The supersaturation state was maintained for 2 hr at the concentration of 7.35$\pm$3.3 mg in 900 ml of water without precipitation. The total amount of DDB dissolved from this new formulation was 5.3 and 6.1 times higher, when compared to marketed DDB tablets (25 mg) and capsules (7.5 mg), respectively.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.1-7
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• 2006

The purpose of the present study was to formulate the aqueous solution of 1-cyclopent-3-enylmethyl-6(3,5-dimethyl-benzoyl)-5-ethyl-1H-pyrimidine-2,4-dione (CPD), a novel antivirus compound containing pirimidine structure. For this purpose, the effects of various solubilization agents such as cosolvents [ethanol, propylene glycol (PG), polyethylene glycol 300 (PEG 300), polyethylene glycol 400 (PEG 400), glycerin], surfactants (Tween 80, Cremophor$^{(R)}$ RH40, Cremophor$^{(R)}$ EL, Poloxamer 407, Poloxamer 188) and a complexation agent [hydroxypropyl-${\beta}$-cyclodextrin (HPBCD)] , on the solubility of CPD in aqueous solution were evaluated. The solubility of CPD in water was under $1\;{\mu}g/ml$ at $20^{\circ}C$. Cosolvents such as ethanol, PG, PEG 300, PEG 400 and glycerin did not enhance the solubility of CPD at the $0{\sim}40\%$ concentration range. The solubility of CPD was significantly elevated by the addition of cosolvents over the $80\%$ concentration range. On the other hand, tween 80, Cremophor$^{(R)}$ L, Cremophor$^{(R)}$ RH40, and HPBCD showed enhanced effects on the solubility of CPD. The enhanced effects of Poloxamer 407 or Poloxamer 188 on the CPD solubility were less pronounced compared with tween 80, Cremophor$^{(R)}$ L or Cremophor$^{(R)}$ RH40. As a results, tween 80 aqueous solution was selected as an optimum solvent system. The aqueous solutions containing $20\%$ tween 80 were formulated as a dosing solution containing CPD for its intraperitoneal and intrahypodermic administration, respectively, The formular showed physical stability after stored for 7 days at $4^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• v.34 no.5
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• pp.385-391
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• 2004

The purpose of the present study was to formulate the aqueous solution of $20-O-{\beta}-D-glucopyranosyl-20(S)-protopanaxadiol\;(IH-901)$, an intestinal bacterial metabolic derivative from Ginseng protopanaxadiol saponin. For this purpose, the effects of various solubilization agents such as cosolvents [ethanol, propylene glycol (PG), polyethylene glycol 300 (PEG 300), polyethylene glycol 400 (PEG 400), glycerin], surfactants $(Tween\;80,\;Cremophor^{\circledR}\;RH40,\;Cremophor^{\circledR}\;EL,\;Poloxamer\;407,\;Poloxamer\;188)$ and a complexation agent $[hydroxypropyl-{\beta}-cyclodextrin\;(HPBCD)]$, on the solubility of IH-90l in aqueous solution were evaluated. The solubility of IH-901 in water was under $1\;{\mu}g/ml\;at\;20^{\circ}C$. Cosolvents such as ethanol, PG, PEG 300, PEG 400 and glycerin did not enhance the solubility of IH-901 at the 0 - 40% concentration range. The solubility of IH-901 was significantly elevated by the addition of cosolvents over the 80% concentration range. On the other hand, tween 80, $Cremophor^{\circledR}\;EL,\;Cremophor^{\circledR}\;RH40$ and HPBCD showed enhanced effects on the solubility of IH-901. The enhanced effects of Poloxamer 407 or Poloxamer 188 on the IH-901 solubility were less pronounced compared with $Cremophor^{\circledR}\;EL\;or\;Cremophor^{\circledR}\;RH40$. As a results, $Cremophor^{\circledR}$ aqueous solution was selected as an optimum solvent system. The aqueous solutions containing 10% $Cremophor^{\circledR}\;EL$ and 7% $Cremophor^{\circledR}\;RH40$ were formulated as dosing solutions containing 5.0 mg/ml of IH-901 for its intravenous and oral administration, respectively. The formular showed physical stability after stored for 7 days at $4^{\circ}C$.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.2
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• pp.61-66
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• 2012

Bismuth(Bi) nanoparticles were synthesized at room temperature by a modified polyol process using bismuth(III) carbonate basic as precursor. In addition, some characteristics of the synthesis with respect to the exchange of a capping agent/surface stabilizer and solvent type were observed. When polyvinylpyrroldone was added, the finest Bi nanoparticles were synthesized in diethylene glycol(DEG), while the coarsest nanoparticles were formed in polyethylene glycol(PEG). The particle size immediately after synthesis was proportionate to final particle size which was determined by particle growth through coalescence and aggregation during drying. As a result, the finest Bi particles with the diameter range of several tens of nanometers - 300 nm were finally obtained in DEG. Regardless of the type of capping agent/surface stabilizer, extensive coalescence and aggregation behavior occurred in PEG, resulting in final products agglomerated with coarse particles.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.300.2-300.2
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• 2003

Unlike cationic liposome/DNA complexes, neutralliposomes containing plasmid DNA are stable in blood and does not selectively entrapped in the lung. The objective of this study was to construct neutral liposomes containing plasmid DNA with optimal encapsulation efficiency. Plasmid DNA (pGL2 clone 753,-6 kb) was encapsulated by the freeze/thawing method into liposomes composed of 1-palmitoyl-2-oleyl-sn-glycerol-3-phosphocholine(POPC), didodecyldimethylammonium bromide(DDAB), distaroylphosphatidyl-ethanolamine polyethylene glycol 2000(DSPE-PEG 2000) and DSPE-PEG 2000-maleimide. (omitted)

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2033-2037
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• 2014

A reaction mixture was developed for formation of soft organic monolith that was easily smashed, rinsed, refluxed, filtered, and dried to give monolith particles having high pore volume of macropores. This phase was almost without mesopores. The reaction mixture was composed of methacrylic acid, ethylene glycol dimethacrylate, polyethylene glycol (porogen), and an initiator in a mixed solvent of toluene and isooctane. The selection of porogen and its amount was carefully carried out to obtain the optimized separation efficiency of the resultant phase. The median macropore size was 1.6 ${\mu}m$, and the total pore volume was 3.0-3.4 mL/g. The median particle size (volume based) was 15 ${\mu}m$, and the range of particle size distribution was very broad. Nevertheless the column (1 ${\times}$ 300 mm) packed with this phase showed good separation efficiency (N~10,000-16,000) comparable to that of a commercial column packed with 5 ${\mu}m$ C18 silica particles.