• 응용화학
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• 제15권1호
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• pp.17-20
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• 2011

A disposable light exposure detector kit has been developed by UV curing of a hydrogel material. The devised light exposure detector kit consisted of light sensitive structures, bottom plate, character sheet and sticky back plate. A light exposure detector kit has a serial light sensitive structures that contain various light sensitive dyes such as rhodamine and fluorescein. The light sensitive structure composed of UV curable hydrogel polymer material as a supporing material and photosensitive dye in a certain concentration. The fabrication procedure of the ligh exposure detector kit is very simple and fast due to UV curing procedure of a photopolymerizable hydrogel material such as poly(ethylene glycol) methyl ether acrylate (PEGMEA) and poly(ethylene glycol) diacrylate (PEGDA) with a photosensitive dye. By the proposed fabrication method, various size and shape of a light exposure detector kit could be fabricated using a flexible elastomer mold. Due to a fast and inexpensive fabrication method, the light exposure detector kit could be use a single use for various industrial applications. According to light irradation, the light sensitive structure on a light exposure detector kit could be lose its color by decomposition of a photosensitive dye chemical in the structure. Thus the amount of the exposed light on a substrate could easily be recognised by changing color or transparency of the structure.

• 접착 및 계면
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• 제24권4호
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• pp.113-119
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• 2023

홍합의 수중 접착능력은 도파(DOPA)와 라이신(Lysine), 히스티딘(Histidine)과 같은 홍합접착단백질의 아미노산 잔기가 중요한 역할을 한다고 보고되었고, 이에 따라, 카테콜과 아민기를 동시에 갖는 접착성 카테콜아민(Catecholamine) 물질을 기반으로 다양한 의공학적 연구가 진행되고 있다. 카테콜기가 도입된 키토산은 아민이 풍부한 키토산에 카테콜기를 도입한 카테콜아민으로, 이를 이용하여 조직접착제나 창상치유제, 지혈제, 약물전달체 및 조직공학용 담체 등 다양한 의공학적 적용이 가능하다. 특히, 키토산-카테콜 물질은 지혈제로 미국 및 한국 식품의약품안전처의 승인을 받아, 연구개발에서부터 제품개발까지 이루어진 홍합 모사 물질이다. 이에 본 총설에서는 지혈제로써의 키토산-카테콜 물질에 대한 연구 동향을 살펴보고자 한다. 이를 위해, 카테콜기가 도입됨에 따라 나타나는 키토산-카테콜의 특성, 지혈 메커니즘, 다양한 제형에 대하여 다루고자 한다.

• Clinical Endoscopy
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• 제56권5호
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• pp.604-612
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• 2023

Background/Aims: We developed a new endoscopic submucosal dissection (ESD) simulator and evaluated its efficacy and realism for use training endoscopists. Methods: An ESD simulator was constructed using polyvinyl alcohol hydrogel sheets and compared to a previous ESD simulator. Between March 1, 2020, and December 30, 2021, eight expert endoscopists from three different centers analyzed the procedure-related factors of the simulator. Five trainees performed gastric ESD exercises under the guidance of these experts. Results: Although the two ESD simulators provided overall favorable outcomes in terms of ESD-related factors, the new simulator had several benefits, including better marking of the target lesion's limits (p<0.001) and overall handling (p<0.001). Trainees tested the usefulness of the new ESD simulator. The complete resection rate improved after 3 ESD training sessions (9 procedures), and the perforation rate decreased after 4 sessions (12 procedures). Conclusions: We have developed a new ESD simulator that can help beginners achieve a high level of technical experience before performing real-time ESD procedures in patients.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1229-1238
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• 2024

This study aimed to develop and assess a chitosan biomedical antibacterial gel ZincOxide-GrapheneOxide/Chitosan/β-Glycerophosphate (ZnO-GO/CS/β-GP) loaded with nano-zinc oxide (ZnO) and graphene oxide (GO), known for its potent antibacterial properties, biocompatibility, and sustained drug release. ZnO nanoparticles (ZnO-NPs) were modified and integrated with GO sheets to create 1% and 3% ZnO-GO/CS/β-GP thermo-sensitive hydrogels based on ZnO-GO to Chitosan (CS) mass ratio. Gelation time, pH, structural changes, and microscopic morphology were evaluated. The hydrogel's antibacterial efficacy against Porphyromonas gingivalis, biofilm biomass, and metabolic activity was examined alongside its impact (MC3T3-e1). The findings of this study revealed that both hydrogel formulations exhibited temperature sensitivity, maintaining a neutral pH. The ZnO-GO/CS/β-GP formulation effectively inhibited P. gingivalis bacterial activity and biofilm formation, with a 3% ZnO-GO/CS/β-GP antibacterial rate approaching 100%. MC3T3-e1 cells displayed good biocompatibility when cultured in the hydrogel extract.The ZnO-GO/CS/β-GP thermo-sensitive hydrogel demonstrates favorable physical and chemical properties, effectively preventing P. gingivalis biofilm formation. It exhibits promising biocompatibility, suggesting its potential as an adjuvant therapy for managing and preventing peri-implantitis, subject to further clinical investigations.

• 폴리머
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• 제30권3호
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• pp.196-201
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• 2006

온도감응성 고분자인 폴리 (에틸렌 글리콜)을 기본으로 하는 다이블록 및 트리블록 폴리에스테르 공중합체들은 비독성과 생체적합성 그리고 생분해성 특징 때문에 조직공학 분야 및 주사제형의 약물전달체에서 많은 응용이 이루어지고 있다. 본 연구에서는 다이블록 공중합체를 이용한 솔-젤 전이 현상을 갖는 고분자를 평균분자량 750 g/mole의 메톡시 폴리 (에틸렌 글리콜)과 카프로락톤을 실온에서 HCl $Et_2O$ 존재 하에서 개환중합을 통하여 합성하였다. 이 공중합체를 이용하여 in vivo상에서 골수간엽줄기세포와 골유도물질인 덱사메타손의 존재 여부에 따라 골분화의 가능성을 조사하였다. 조직을 파라핀으로 고정시켜 슬라이드를 제조한 후 hematoxylin & eosin, 본쿠사 및 오스테오칼신 염색을 통하여 골형성 정도를 확인하였다. 결론적으로 덱사메타손이 함유된 젤이 골형성에 도움을 주지만 젤만으로는 강한 골형성을 유도할 수 없으므로 줄기세포나 다른 골형성 유도재료를 사용하면 우수하게 골형성 효과를 가져올 것이라고 판단되었다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.263-263
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• 2006

Poly (ethylene glycol)(PEG) - Poly (${\varepsilon}-caprolactone(CL)$) - Poly (D,L lactide(LA) (PCLA-PEG-PCLA) was synthesized by ring-opening polymerization to form temperature sensitive hydrogel triblock copolymer. The triblock copolymer was acrylated by acryloyl chloride. ${\beta}-amino$ ester was used as a pH sensitive moiety, in this study ${\beta}$- amino ester obtained from 1,4-butandiol diacrylate, and 4, 4' trimethylene dipiperidine, it have pKb around 6.6. pH/temperature sensitive penta-block copolymer (PAE-PCL-PEG-PCL-PAE) was synthesized by addition polymerization from acrylated triblock copolymer, 1,4-butandiol diacrylate, and 4, 4' trimethylene dipiperidine. Their physicochemical properties of triblock and penta-block copolymers were characterized by $^1H-NMR$ spectroscopy and gel permeation spectroscopy. Sol-gel phase transition behavior of PAE-PCL-PEG-PCL-PAE block copolymers were investigated by remains stable method. Aqueous media of the penta-block copolymer (at 20 wt%) changed from a sol phase at pH 6.4 and $10^{\circ}C$ to a gel phase at pH 7.4 and $37^{\circ}C$. The sol-gel transition properties of these block copolymers are influenced by the hydrophobic/hydrophilic balance of the copolymers, block length, hydrophobicity, stereo-regularity of the hydrophobic of the block copolymer, and the ionization of the pH function groups in the copolymer depended on the changing of environmental pH, respectively. The degradation and the stabilization at pH 7.4 and $37^{\circ}C$, and the stabilization at pH 6.4 and $10^{\circ}C,\;5^{\circ}C,\;0^{\circ}C$, of the gel were determined. The results of toxicity experiment show that the penta block copolymer can be used for injection drug delivery system. The sol?gel transition of this block copolymer also study by in vitro test ($200{\mu}l$ aqueous solution at 20wt% polymer was injected to mouse). Insulin loading and releasing by in vitro test was investigated, the results showed that insulin can loading easily into polymer matrix and release time is around 14-16days. The PAE-PCL-PEG-PCL-PAE can be used as biomaterial for drug, protein, gene loading and delivery.

• 폴리머
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• 제34권5호
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• pp.459-463
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• 2010

전신 진균감염 치료에 널리 사용되는 광범위 항진균제이며 대표적인 소수성 약물인 amphotericin B(AmB)의 효과적인 점막부착형 약물전달체로서 가용화제인 L-arginine, 점착성 고분자인 카보폴(carbopol), 온도감응성 고분자인 Poloxamer 407(P 407)로 구성된 하이드로젤 제형을 제조하였다. L-Arginine의 첨가로 AmB의 용해도가 2.6 mg/mL까지 향상되었으며, P 407 수용액은 20% w/v 이상의 농도에서 온도 변화에 따른 졸-젤-졸 상전이(phase transition)를 보였다. 이러한 상전이 온도는 약물 및 L-arginine의 존재에 의해 영향을 받았고, 점착성 고분자인 카보폴의 혼합에 의해 상전이 영역이 확장되었다. L-Arginine의 가용화 효과로 AmB의 약물방출특성이 향상되었고, 점착성 고분자인 카보폴의 첨가는 농도에 의존하여 약물방출을 지연시키는 효과가 있었다.

• Molecules and Cells
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• 제38권7호
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• pp.663-668
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• 2015

hBMSCs are multipotent cells that are useful for tissue regeneration to treat degenerative diseases and others for their differentiation ability into chondrocytes, osteoblasts, adipocytes, hepatocytes and neuronal cells. In this study, biodegradable elastic hydrogels consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(${\varepsilon}$-caprolactone) (PCL) scaffolds were evaluated for tissue engineering because of its biocompatibility and the ability to control the release of bioactive peptides. The primary cultured cells from human bone marrow are confirmed as hBMSC by immunohistochemical analysis. Mesenchymal stem cell markers (collagen type I, fibronectin, CD54, $integrin1{\beta}$, and Hu protein) were shown to be positive, while hematopoietic stem cell markers (CD14 and CD45) were shown to be negative. Three different hydrogel scaffolds with different block compositions (PEG:PCL=6:14 and 14:6 by weight) were fabricated using the salt leaching method. The hBMSCs were expanded, seeded on the scaffolds, and cultured up to 8 days under static conditions in Iscove's Modified Dulbecco's Media (IMDM). The growth of MSCs cultured on the hydrogel with PEG/PCL= 6/14 was faster than that of the others. In addition, the morphology of MSCs seemed to be normal and no cytotoxicity was found. The coating of the vascular endothelial growth factor (VEGF) containing scaffold with Matrigel slowed down the release of VEGF in vitro and promoted the angiogenesis when transplanted into BALB/c nude mice. These results suggest that hBMSCs can be supported by a biode gradable hydrogel scaffold for effective cell growth, and enhance the angiogenesis by Matrigel coating.

• 한국해양바이오학회지
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• 제7권2호
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• pp.58-70
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• 2015

Injectable RGD-bioconjugated Mussel Adhesive Proteins (RGD-MAPs) composite hydroxypropyl methylcellulose (HPMC) hydrogels provide local periodontal tissue for bone filling in periodontal surgery. Previously we developed a novel type of injectable self-supported hydrogel (2 mg/ml of RGD-MAPs/HPMC) based porcine nano hydroxyapatite (MPH) for dental graft, which could good handling property, biodegradation or biocompatibility with the hydrogel disassembly and provided efficient cell adhesion activity and no inflammatory responses. Herein, the aim of this work was to evaluate bone formation following implantation of MPH and collagen membrane in rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created on each animal. Defects were filled with different graft materials: 1) collagen membrane, 2) collagen membrane with MPH, 3) collagen membrane with bovine bone hydroxyapatite (BBH), and 4) control. The animals were sacrificed after 2 and 8 weeks of healing periods for histologic analysis. Both sites receiving MPH and BBH showed statistically increased augmented volume and new bone formation (p < 0.05). However, there was no statistical difference in new bone formation between the MPH, BBH and collagen membrane group at all healing periods. Within the limits of this study, collagen membrane with MPH was an effective material for bone formation and space maintaining in rabbit calvarial defects.

• 생명과학회지
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• 제24권4호
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• pp.437-446
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• 2014

트립탄 계열의 약물을 경구 복용 시에 트립탄은 소화 시스템에 의하여 생물학적 이용도가 감소되며, 혈중 약물 농도가 시간의 경과에 따라 급격히 감소되고, 위장 장애의 가능성 등이 있다는 문제들을 나타낸다. 일반 겔 패치의 부작용을 개선하기 위하여 패치는 하이드로겔 형태로 제조하였다. 하이드로겔 패치의 주가 되는 메트릭스의 고분자는 PVA를 사용하였고, PEG는 PVA의 분자 간/분자 내 수소결합을 유도하기 위해 첨가물로서 사용되었고 알모트립탄 약물이 부가되었다. 또한 PVA 체인간의 미세 상분리를 가속하기 위해 매우 낮은 온도에서 액체질소가 사용되었다. FT-IR 분석에서 PVA, PEG 그리고 알모트립탄의 흡수 밴드를 확인하였다. PEG 함량이 증가함에 따라 결정화도, 수분흡수력과 인장강도들은 증가하였다. 약물방출 실험에서 약물 방출량은 PEG의 함량이 높은 하이드로겔이 약물 방출 시에 팽윤이 더 잘 이루어져 증가하였다. 본 실험에서 10 wt%의 PEG를 첨가하여 제조된 하이드로겔의 약물 방출량이 가장 좋았다. 또한 10 wt%의 PEG가 함유된 하이드로겔은 2시간째까지 전체 약물의 약 60%가 방출됨을 확인하였고, 24시간째까지도 방출이 계속되었다. 따라서 제조된 하이드로겔은 triptan의 1차 투여 이후 24시간 이내에 재발하는 편두통 환자들을 대상으로 한 트립탄의 2차 투여를 위한 경피흡수형 패치로서 적합하다.