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Hui-Jeong Gwon,Youn-Mook Lim,Young-Chang Nho,장호남,심재운,권일근,김성은 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.3
Biocompatible and pH-responsive poly(ethylene glycol) (PEG)-acrylic acid (AAc) hydrogels were prepared by new technique using γ-irradiation for controlled oral drug delivery. The gel fraction was over 80% and the equal amounts of PEG and AAc blended hydrogel had efficient insulin loading using equilibrium swelling. These hydrogels exhibited unique pH-responsive characteristics in which interpolymer complexes were formed in acidic media and dissociated in neutral or basic environments. The insulin release from the gel was significantly retarded in acidic media while rapid release occurred under neutral/basic conditions. At the high pH solution, the gels swelled rapidly and over 70% of the insulin loaded was released over a period of 10 h. Within 2 h of administration of the insulin-containing gels, significant blood glucose reduction effects were observed in diabetic rats. The blood glucose reduction lasted for up to 10 h following administration.
Identification of Novel Non-Metal Haloperoxidases from the Marine Metagenome
( Hui Jeong Gwon ),( Ide Teruhiko ),( Harayama Shigeaki ),( Sang Ho Baik ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.6
Haloperoxidase (HPO, E.C.1.11.1.7) is a metal-containing enzyme oxidizing halonium species, which can be used in the synthesis of halogenated organic compounds, for instance in the production of antimicrobial agents, cosmetics, etc., in the presence of halides and H2O2. To isolate and evaluate a novel non-metal HPO using a culture-independent method, a cassette PCR library was constructed from marine seawater in Japan. We first isolated a novel HPO gene from Pseudomonas putida ATCC11172 by PCR for constructing the chimeric HPO library (HPO11172). HPO11172 showed each single open-reading frame of 828 base pairs coding for 276 amino acids, respectively, and showed 87% similarity with P. putida IF-3 sequences. Approximately 600 transformants screened for chimeric genes between P. putida ATCC11173 and HPO central fragments were able to identify 113 active clones. Among them, we finally isolated 20 novel HPO genes. Sequence analyses of the obtained 20 clones showed higher homology genes with P. putida or Sinorhizobium or Streptomyces strains. Although the HPO A9 clone showed the lowest homology with HPO11172, clones in group B, including CS19, showed a relatively higher homology of 80%, with 70% identy. E. coli cells expressing these HPO chimeric genes were able to successfully bioconvert chlorodimedone with KBr or KCl as substrate.
Gwon, Hui-Jeong,Lim, Youn-Mook,Nho, Young-Chang,Baik, Sang-Ho Elsevier 2010 Radiation physics and chemistry Vol.79 No.5
<P><B>Abstract</B></P><P>To evaluate the effect of humectants such as glycerol, poly(vinyl alcohol)/glycerol (P/G) hydrogels were prepared by using γ-ray irradiation followed by freeze thawing (FT). The gel fraction ratio (<I>G</I>) and equilibrium swelling ratio (<I>S</I>) of the P/G hydrogels were investigated as functions of glycerol content and FT cycles. Interestingly, <I>G</I> increases while <I>S</I> decreases with increase in glycerol content. This result indicates that even if the glycerol is useful to improve the smoothness and moisture of the hydrogels, further consideration of conditioning the use of glycerol to improve the absorption of exudates from wounds for an advanced wound healing is needed.</P>
One-step synthesis of gene carrier via gamma irradiation and its application in tumor gene therapy
Jeong, Sung In,Park, Seong-Cheol,Park, Sun-Jeong,Kim, Eun-Ji,Heo, Hun,Park, Jong-Seok,Gwon, Hui-Jeong,Lim, Youn-Mook,Jang, Mi-Kyeong DOVE MEDICAL PRESS 2018 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.13 No.-
<P><B>Introduction</B></P><P>Although numerous studies have been conducted with the aim of developing drug-delivery systems, chemically synthesized gene carriers have shown limited applications in the biomedical fields due to several problems, such as low-grafting yields, undesirable reactions, difficulties in controlling the reactions, and high-cost production owing to multi-step manufacturing processes.</P><P><B>Materials and methods</B></P><P>We developed a 1-step synthesis process to produce 2-aminoethyl methacrylate-grafted water-soluble chitosan (AEMA-g-WSC) as a gene carrier, using gamma irradiation for simultaneous synthesis and sterilization, but no catalysts or photoinitiators. We analyzed the AEMA graft site on WSC using 2-dimensional nuclear magnetic resonance spectroscopy (2D NMR; 1H and 13C NMR), and assayed gene transfection effects in vitro and in vivo.</P><P><B>Results</B></P><P>We revealed selective grafting of AEMA onto C6-OH groups of WSC. AEMA-g-WSC effectively condensed plasmid DNA to form polyplexes in the size range of 170 to 282 nm. AEMA-g-WSC polyplexes in combination with psi-hBCL2 (a vector expressing short hairpin RNA against <I>BCL2</I> mRNA) inhibited tumor cell proliferation and tumor growth in vitro and in vivo, respectively, by inducing apoptosis.</P><P><B>Conclusion</B></P><P>The simple grafting process mediated via gamma irradiation is a promising method for synthesizing gene carriers.</P>
Preparation and Characterization of Radiation Fabricated β-Glucan Hydrogels for Wound Dressing
Hui-Jeong Gwon(권희정),Sung-Jun Ahn(안성준),Jin-Oh Jeong(정진오),Su-Min Kim(김수민),Jong-Seok Park(박종석),Sung In Jeong(정성린),Young-Chang Nho(노영창),Youn-Mook Lim(임윤묵) 한국고분자학회 2017 폴리머 Vol.41 No.4
화학가교제의 사용없이 감마선을 이용하여 β-glucan, poly(vinyl alcohol)(PVA), poly(vinyl pyrrolidone)(PVP), κ-carrageenan(κC), glycerin으로 구성된 고분자 하이드로젤을 제조하였다. 25, 50, 75 kGy로 감마선 조사선량을 달리하여 하이드로젤을 제조한 후, 젤화율, 팽윤도, 압축강도의 측정을 통해 제조된 하이드로젤의 물리적 특성을 확인하였다. 조사선량의 증가에 따라 하이드로젤의 가교밀도가 증가되어 젤화율과 압축강도는 증가하였고, 팽윤도는 감소되었다. 제조된 베타글루칸 하이드로젤로 손상된 조직의 재생 특성을 평가해 보기 위해 동물실험을 수행하였고, 그 결과 베타글루칸이 함유된 하이드로젤이 빠른 상처 치유능을 나타내었고, 상용제품과 비교 시에도 동등한 치료효과를 관찰할 수 있었다. 따라서 감마선으로 제조된 β-glucan/PVA/PVP/κC/glycerin 하이드로젤은 화학가교제 독성의 우려 없이 β-glucan에 의한 향상된 치료효과와 더불어 향후 조직재생용 소재로서 유용하게 사용될 수 있을 것으로 사료된다. Hydrogels consisted of β-glucan, poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), κ-carrageenan (κC) and glycerin were prepared by gamma-ray irradiation for damaged tissue regeneration. Irradiation doses of 25, 50, and 75 kGy were exposed, respectively, to the β-glucan hydrogel to evaluate the effect of irradiation dose on physical properties. The physical properties were examined such as gel fraction, absorption ratio, and compressive strength. It was found that the gel fraction and the compressive strength increased with increasing the irradiation dose. This is due to the fact that the crosslinking density increases with increasing the irradiation dose, whereas the absorption ratio decreased with increasing the irradiation dose. On observing the wound healing of rat skin, the resulting hydrogels accelerated the wound repair, which can be attributed to the release of β-glucan from the hydrogel. Therefore, radiation fabricated β-glucan/PVA/PVP/κC/glycerin blended hydrogel was suitable for wound healing and could be considered as good tissue regeneration biomaterials without chemical toxicity.
Gwon, Hui-Jeong,Yoshioka, Hideki,Song, Nho-Eul,Kim, Jong-Hui,Song, Young-Ran,Jeong, Do-Youn,Baik, Sang-Ho M. Dekker 2012 PREPARATIVE BIOCHEMISTRY AND BIOTECHNOLOGY Vol.42 No.2
<P>This study examined the efficient production and optimal separation procedures for pure L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) from a mixture of diastereomers synthesized by whole-cell aldol condensation reaction, harboring diastereoselectivity-enhanced L-threonine aldolase in Escherichia coli JM109. The addition of the reducing agent sodium sulfite was found to stimulate the production of L-threo-DOPS without affecting the diastereoselectivity ratio, especially at the 50 mM concentration. The optimal pH for diastereoselective synthesis was 6.5. The addition of Triton X-100 also strongly affected the synthesis yield, showing the highest conversion yield at a 0.75% concentration; however, the diastereoselectivity of the L-threonine aldolase was not affected. Lowering the temperature to 10C did not significantly affect the diastereoselectiviy without affecting the synthesis rate. At the optimized conditions, a mixture of L-threo-DOPS and L-erythro-DOPS was synthesized by diastereoselectivity-enhanced L-threonine aldolase from E. coli in a continuous process for 100 hr, yielding an average of 4.0 mg/mL of L-threo-DOPS and 60% diastereoselectivity (de), and was subjected to two steps of ion exchange chromatography. The optimum separation conditions for the resin and solvent were evaluated in which it was found that a two-step process with the ion-exchange resin Dowex 50 W 8 and activated carbon by washing with 0.5 N acetic acid was sufficient to separate the L-threo-DOPS. By using two-step ion-exchange chromatography, synthesized high-purity L-threo-DOPS of up to 100% was purified with a yield of 71%. The remaining substrates, glycine and 3,4-dihydroxybenzaldehyde, were recovered successfully with a yield of 71.2%. Our results indicate this potential procedure as an economical purification process for the synthesis and purification of important L-threo-DOPS at the pharmaceutical level.</P>
Characterization of PVA/glycerin hydrogels using γ-irradiation for advanced wound dressings
Hui-Jeong Gwon,Youn-Mook Lim,Sung-Jun An,Min-Ho Youn,Seol-Hee Han,장호남,Young-Chang Nho 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6
The aim of this study was to investigate the enhanced absorption property of PVA/Glycerin (PVA/Gly) hydrogel for advanced wound dressing. A simple crosslinking method was introduced to prepare the PVA/Gly hydrogels with the use of γ-irradiation. An absorption ratio and thermal properties of the PVA/Gly hydrogels can be controlled by varying the irradiation dose and weight ratio of the PVA/Gly. When the PVA/Gly content was 20/5 wt% and the irradiation dose at 25 kGy, the PVA/Gly hydrogels showed excellent absorption properties (>350%). These results imply that the PVA/Gly hydrogel is highly absorbent and converts wound exudates to the hydrogel matrices that create a moist and clean environment in the wound healing process. Therefore, the PVA/Gly hydrogel prepared by this method can be used as an advanced wound dressing.
방사선을 이용한 느릅나무 추출 다당류가 함유된 하이드로젤의 제조 및 항염증성 평가
권희정(Hui Jeong Gwon),박은지(Eun Ji Park),최종배(Jong Bae Choi),임종영(Jong Young Lim),정진오(Jin Oh Jeong),신영민(Young Min Shin),정성린(Sung In Jeong),박종석(Jong Seok Park),임윤묵(Youn Mook Lim),최영훈(Young Hun Choi),김상숙(Sang 한국고분자학회 2014 폴리머 Vol.38 No.1
본 연구에서는 방사선 기술을 이용하여 항염증 특성을 가지는 천연 추출물을 함유하는 고분자 하이드로젤을 제조하여 항염증 패치로서의 유용성을 확인하였다. 천연 추출물로는 오래 전부터 전통 민간요법으로 항염제나 궤양 및 종양 치료 등에 사용되고 있는 느릅나무를 사용하였고, 생체 적합성 고분자인 poly(vinyl alcohol)(PVA)와 보습률 향상을 위해 글리세린을 첨가하여 감마선 가교에 의해 다당류 함유 고분자 하이드로젤을 제조하였다. 제조된 하이드로젤은 항염증 패치로 사용하기에 우수한 기계적 물성을 나타내었고, 사이토카인 분비를 효과적으로 억제함은 물론 세포독성도 나타나지 않는 것을 확인하였다. 결론적으로 느릅나무 추출 다당류가 함유된 하이드로젤은 항염증패치로써 유용하게 사용될 수 있음을 확인하였다. In this study, polysaccharide-poly(vinyl alcohol) (PVA) hydrogels were prepared by using γ-ray and evaluatedfor potential application as an anti-inflammation patch. Ulmus davidiana var. japonica (UD), one of polysaccharides hasbeen particularly used as an oriental remedy for the treatment of inflammation and ulcers. PVA as a biocompatible polymerand glycerin as a moisturizer were blended with the UD, and its hydrogels were prepared by radiation crosslinking. Characterizations for UD hydrogels were performed by using cytotoxicity assay, antioxidant activity test, and physicochemicaltest such as gel fraction ratio, and swelling behavior. The results showed that these UD hydrogels had excellentphysical properties, anti-inflammation activity, and non-cytotoxicity on the cells. Therefore, these polysaccharidebased-UD hydrogels can be effectively used as an inflammation patch.