• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.219-223
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• 2010

The hyaluronic acid (HA) conjugate bearing $\alpha$-cyclodextrin ($\alpha$-CD) was synthesized as the potential carrier of poly(ethylene glycol) (PEG)-drug conjugates. The HA conjugate was prepared by the reaction between the carboxylic acid of HA and the primary amine of $\alpha$-CD in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1-hydroxybenzotriazole. The chemical structure of the conjugate was confirmed using $^1H$ NMR and FT-IR spectroscopy. The conjugate could form nano-sized particles in the presence of PEG by forming the inclusion complexes between $\alpha$-CD at the backbone of HA, which was demonstrated using electrophoretic light scattering and field emission transmission electron microscopy. It is anticipated that this novel kind of nanoparticles can serve as a useful delivery system for PEGylated drugs.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.179-180
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• 2003

ABA triblock copolymer made up of long middle block(B) and sho.1 terminal blocks(A) is being widely used as thermoplastic elastomers. Block copolymers with non-polar hydrophobic polystyrene and polar hydrophilic poly(ethylene glycol) blocks has been prepared and the physical properties of the solutions of PS-PEG-PS in polar (dimethyl formamide, DMF) and non-polar solvent (benzene) were investigateded[-3]. (omitted)

• 동굴
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• 제76호
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• pp.1-13
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• 2006

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode is studied. Poly(ethylene glycol) was coordinated to a structure formed by the EPD process with YBCO particles. The suspension is characterized in terms of zeta potential and conductivity. The d.c electric fields of 200-300 V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the c-axis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of submicrometer-sized pores and randomly orientated grains were prepared from the solution without PEG.

• 대한화장품학회지
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• 제25권1호
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• pp.107-119
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• 1999

3 Kinds of PEG-hEGF conjugate, PEG5-hEGF, PEG5-hEGF, PEG10-hEGF, were synthesized. Major fractions containing 2 chains of PEG were separated by preparative GPC. Molecular weight was estimated by GPC-MALLS, TOF-Mass and SDS-PAGE, and the data were well corresponding to calculated one. The cell proliferation effect of the conjugates was evaluated, Indicating that the conjugate bound to longer chain PEG exhibits lower activity. Selective modification of hEGF and activity preservation of PEG-hEGF conjugate are undergoing.

• KSBB Journal
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• 제15권6호
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• pp.556-559
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• 2000

Cyclodextrin Glucanotransferase(EC 2.4.1.19 : 1,4-${\alpha}$-glucano) transferase, cyclizing; CGTase) can be separated and recovered in an aqueous two-phase system composed of poly(ethylene glycol)(PEG)/dextran and PEG/salt. In an aqueous two-phase system consisting of PEG 35000 (5%) and dextran T2000 (7%), all cell and debris were collected at the interphase. CGTase partitioned to the denser dextran phase at an yield of 83.4%. On the other hand, in an aqueous two-phase system consisting of PEG 35000 (10%) and sodium phosphate (15%), CGTase partitioned to the denser salt phase at an yield of 95.5%. In order to recover CGTase using an aqueous two-phase system, the PEG/salt system proved to be more efficient than the PEG/dextran system in terms of yield and cost.

• 대한화학회지
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• 제56권3호
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• pp.316-321
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• 2012

Poly(ethylene glycol) (PEG) has been used as a sustainable, non-volatile, and environmentally friendly reaction solvent for the synthesis of functionalized benzene/biaryl and fluoren-9-one derivatives from activated acetylenes and 1,3-diones at $100^{\circ}C$. No additional solvent and catalyst are required.

• 약학회지
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• 제48권1호
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• pp.82-87
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• 2004

Mungbean trypsin inhibitor (MBTI) was isolated and purified from Mung bean which has been used as a galenic and traditional food. MBTI and poly(ethylene glycol) were conjugated by using water soluble carbodiimide. We evaluated the therapeutic value of the MBTI and MBTI-PEG conjugate using animal models, sublethal septic shock model in guinea pig caused by pseudomonal elastase, shock model in rat caused by lipopolysaccharide, and the vascular permeability test by using pseudomonal elastase. In two shock model in guinea p Is and in rat, hypotesion shock was inhibited by pretreatment of MBTI. And also the vascular permeability caused by pseudomonal elastase reduced by pretreatment of MBTI. Also, therapeutic value of the MBTI-PEG conjugate was evaluated by using the sublethal septic shock model caused by pseudomonal elastase. The MBTI-PEG conjugate was more effective than native MBTI against pseudomonal elastase induced septic shock in guinea pig model.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3735-3739
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• 2010

Branched oligopeptides prepared by coupling a very hydrophobic aspartic diamino acid ethyl ester such as Asp $(LeuEt)_2$, $Asp(IleEt)_2$ and $Asp(PheEt)_2$ to glycine or glycylphenylalanine were grafted to the cyclotriphosphazene backbone bearing an equimolar hydrophilic poly(ethylene glycol) (PEG). The properties of the resultant amphiphiles were examined in comparison with those of the linear oligopeptide analogues previously reported. All cyclic phosphazene trimers grafted with the branched tetra- and pentapeptides displayed a normal trend of thermosensitivity depending on their hydrophilic to hydrophobic balance, but the stability and particle size of their micelles were found to be greatly dependent on the fine structure of the branched oligopeptides grafted. The trimers bearing branched tetrapeptides with a low hydrophobicity were found to form unstable micelles initially, which reassemble into thermodynamically more stable polymersomes.

• Macromolecular Research
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• 제12권1호
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• pp.63-70
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• 2004

We have synthesized various types of poly(ethylene glycol) (PEG)-ibuprofen conjugates by the nucleophilic substitution of bromo-terminated PEG with ibuprofen-Cs salt; PN (Pluronic) was also used in place of PEG. All the bromo-terminated PEGs and PN were obtained in high yield. Conversions of the terminal hydroxyl groups to bromo-termini were quantitative, as were the drug conjugation processes. The Ι$_1$/Ι$_3$values obtained from solutions of the ibuprofen-conjugated prodrugs are summarized in relation to those of ibuprofen in water and in aqueous solutions of the original PEG, PN, and several ordinary surfactants. We believe that the fully hydrophilic PEG is completely hydrated and forms no hydrophobic pocket by segment aggregation. These results indicate that the probe environment is significantly hydrophobic, particularly in the solution of prodrug PN, for which the ratio is similar to that obtained from typical micelles of surfactants. The results suggest, therefore, that the present synthetic method is very useful for preparing PEG-based prodrugs from pharmaceuticals having carboxyl functionalities.

• Macromolecular Research
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• 제12권1호
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• pp.38-45
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• 2004

A highly flexible polyimide (PI) was synthesized successfully from ethylene glycol bis(anhydrotrimellitate) (TMEG) and 1,3-bis(4-aminophenoxy)benzene (TPER) for its application in electronics. To enhance the thermal stability and mechanical properties of this novel PI, we prepared PI nanocomposite films using nanoparticles of clays that had been treated with organic intercalating agents (organoclays). We used two types of organoclays: montmo-rillonite (MMT) treated with hexadecylamine (C$\_$16/) and MMT treated with dimethyl dihydrogenated tallow quaternary ammonium (l5A). PI/organoclay hybrid films were obtained by first preparing poly(amic acid) (PAA)/organoclay films and then converting the PAA to polyimide by thermal conversion. PAA was characterized by FT-IR and $^1$H-NMR spectroscopy and the conversion of PAA to PI was confirmed by FT-IR spectroscopy. We analyzed the dispersion of the organoclays in the PI film by X-ray diffraction. The thermal stability and mechanical properties of the hybrid films were also investigated.