• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.49-52
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• 2002

합성 고분자의 생분해는 환경 보존이라는 측면에서 중요시 되고 있으며 봉합사나 bone fixation, 그리고 implant와 같은 의학적 응용면에서도 상당한 관심의 대상이 되어오고 있다 glycolic acid, L-lactic acid, $\varepsilon$-caprolactone에 근거하는 지방족 폴리에스터는 생분해성 봉합사로서 응용되고 있으나 여전히 열적, 기계적 가공특성과 같은 적정특성들이 부족하다.$^1$ 한편 폴리아마이드는 유사한 구조를 갖는 폴리에스터와 비교할 때에 상대적으로 높은 유리전이온도와 높은 융점을 가지고 있는 반면 높은 흡습성으로 인한 물성저하가 야기될 수 있다. (중략)

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.255-255
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• 2006

Polymeric nanoparticles are recognized as promising drug carriers [1]. Here, novel tri-block copolymers based on poly PPDO, PCL and PEG were synthesized and employed for the formulation of reproducible polymeric nanoparticles [2]. To estimate the feasibility of the polymer to form polymeric nanoparticles, nanoparticles were prepared by co-solvent evaporation technique. Polymerization and structural features of the polymer were analyzed by different physico-chemical techniques. Existence of hydrophobic domains as a core of nanoparticles was characterized by $^{1}H-NMR$ spectroscopy, and further confirmed by fluorescence technique using pyrene as probe.

• Fibers and Polymers
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• 제3권3호
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• pp.103-108
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• 2002

The viscosity effect of matrix polymer on melt exfoliation behavior of an organoclay in poly($\varepsilon$-caprolactone) (PCL) was investigated. The viscosity of matrix polymer was controlled by changing the molecular weight of poly($\varepsilon$-eaprolactone), the processing temperature, and the rotor speed of a mini-molder. Applied shear stress facilitates the diffusion of polymer chains into the gallery of silicate layers by breaking silicate agglomerates down into smaller primary particles. When the viscosity of PCL is lower, silicate agglomerates are not perfectly broken into smaller primary particles. At higher viscosity, all of silicate agglomerates are broken down into primary particles, and finally into smaller nano-scale building blocks. It was also found that the degree of exfoliation of silicate layers is dependent upon not only the viscosity of matrix but thermodynamic variables.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.45.2-45.2
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• 2009

A coronary graft fabricated from PLGA poly (lactic-co-glycolic acid) and chitosan electros puns deposited on poly caprolactone (PCL) electro spun tube. Mechanical properties of tube were evaluated through extruder machine depending on thickness of vessel wall. Biocompatible properties were evaluated by SEM morphology, amount of cell counting and MTT assay method for depending on culture days (1, 3, 5 days). MTT assay, counting cell and SEM morphology showed that cells were fast growth and immigration after 5 days. Biodegradability was monitored through loss weigh method for incubator days.

• 폴리머
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• 제39권1호
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• pp.40-45
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• 2015

혈항혈전성 표면의 제조를 위해 간단한 비용매 휘발 방법을 통하여 고탄성체이면서 생분해성 폴리 락티드-카프로락톤 공중합체 필름의 표면상에 연잎 구조물과 유사한 마이크로 돌기를 만들어 주었다. 표면 구조와 소수성도, 항혈전 효과 등을 시험했으며, 결정화도와 탄성회복률 등의 물리적 특성도 분석하였다. 그 결과 비용매와 메틸렌클로라이드의 혼합 부피비 1:2에서 연잎표면과 유사한 최적의 효과를 얻었으며, 이때 수접촉각은 $124^{\circ}$였다. 혈소판 부착시험에서는 처리하지 않는 군에 비해 약 10%만 부착되는 효과를 확인할 수 있었다.

• Korea-Australia Rheology Journal
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• 제12권2호
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• pp.101-105
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• 2000

The crystallization behavior of homo polypropylene (PP) and PP in the PP-poly($\varepsilon$-caprolactone) (PCL) blends during isothermal crystallization has been investigated using differential scanning calorimeter (DSC) and advanced rheometric expansion system (ARES). From the storage modulus data of the homo PP and PP-PCL blends during isothermal crystallization, the volume fraction of crystallized material ($X_t$) of the homo PP and PP in the PP-PCL blends was calculated using the various rheological models. The results of $X_t$ of the homo PP and PP in the PP-PCL blends from ARES measurement were compared with the results from DSC. The $X_t$ of the homo PP was found to be higher in the ARES measurement than in the DSC. The crystallization rate of the homo PP was found to be faster in the rheological measurements than in the thermal analysis. The $X_t$ of PP in the PP-PCL blends with various compositions was obtained from the thermal analysis and rheological measurements. The $X_t$ of PP in the PP-PCL blends obtained from the thermal analysis and rheological measurements are not consistent. This discrepancy of $X_t$ may be due to the morphological changes resulted from the different crystallization kinetics of PP in the PP-PCL blends.

• 폴리머
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• 제26권3호
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• pp.326-334
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• 2002

본 실험에서는 PCL 마이크로캡슐을 제조하여 형태적 분석 및 제조 조건에 따른 특성을 살펴보고 약물방출거동을 통하여 약물전달체계로서의 가능성을 고찰하였으며 액중건조법을 사용하여 약물을 함유한 마이크로캡슐을 제조하였다. 마이크로캡슐 입경과 형태는 교반속도, 교반시간 그리고 유화제의 농도에 따라 어떠한 영향을 받는가에 대하여 관찰하였다. 마이크로캡슐의 모양과 표면을 image analyzer와 SEM으로 관찰한 결과 제조된 마이크로캡슐은 평균 입경이 40~400$\pm$20 $mu extrm{m}$로 주름이 발달된 구형의 형태였다. 제조된 PCL 마이크로캡슐의 약물함유 여부는 FT-IR을 사용하여 확인하였고 접촉각 측정을 통해 PCL과 약물간의 계면에서의 부착일을 살펴보았다. 또한 방출거동을 살펴보기 위해 UV/vis. 흡광광도법으로 흡광도를 측정하여 용출된 약물비 양을 정량 하였으며, 그 결과, 유화제의 농도를 높게 하여 제조한 마이크로캡슐의 약물 방출이 상당히 빠름을 알 수 있었다.

• 대한의용생체공학회:의공학회지
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• 제34권3호
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• pp.111-116
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• 2013

Finite element analysis(FEA) has been extensively applied in the analyses of biomechanical properties of stents. Geometrically, a closed-cell stent is an assembly of a number of repeated unit cells and exhibits periodicity in both longitudinal and circumferential directions. This study concentrates on various parameters of the FEA models for the analysis of drug-eluting biodegradable polymeric stents for application to the treatment of coronary artery disease. In order to determine the mechanical characteristics of biodegradable polymeric stents, FEA was used to model two different types of stents: tubular stents(TS) and helicoidal stents(HS). For this modeling, epigallocatechin-3-O-gallate (EGCG)-eluting poly[(L-lactide-co-${\varepsilon}$-caprolactone), PLCL] (E-PLCL) was chosen as drug-eluting stent materials. E-PLCL was prepared by blending PLCL with 5% EGCG as previously described. In addition, the effects of EGCG blending on the mechanical properties of PLCL were investigated for both types of stent models. EGCG did not affect tensile strength at break, but significantly increased elastic modulus of PLCL. It is suggested that FEA is a cost-effective method to improve the design of drug-eluting biodegradable polymeric stents.

• Macromolecular Research
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• 제17권12호
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• pp.1025-1031
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• 2009

Several kinds of biodegradable hydrogels were prepared via in situ photopolymerization of Pluronic F127/poly($\varepsilon$-caprolactone) macromer and acrylic acid (AA) comonomer in aqueous medium. The swelling kinetics measurements showed that the resultant hydrogels exhibited both thermo- and pH-sensitive behaviors, and that this stimuli-responsiveness underwent a fast reversible process. With increasing pH of the local buffer solutions, the pH sensitivity of the hydrogels was increased, while the temperature sensitivity was decreased. In vitro hydrolytic degradation in the buffer solution (pH 7.4, $37^{\circ}C$), the degradation rate of the hydrogels was greatly improved due to the introduction of the AA comonomer. The in vitro release profiles of bovine serum albumin (BSA) in-situ embedded into the hydrogels were also investigated: the release mechanism of BSA based on the Peppas equation was followed Case II diffusion. Such biodegradable dual-sensitive hydrogel materials may have more advantages as a potentially interesting platform for smart drug delivery carriers and tissue engineering scaffolds.

• 방사선산업학회지
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• 제7권1호
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• pp.45-49
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• 2013

In tissue engineering application, a fibrous structure of scaffolds has been issued as an alternative system to regulate cell survival and tissue regeneration, and electrospinning technique has been popularly used to generate fibrous meshes or sheets mimicking the structure of native extracellular matrix (ECM). However, recent strategy in the scaffold development is expanded to provide the structural property as well as a biological property of native ECM, a variety of surface modification techniques have been used to introduce biological property. In this study, we developed biomimetic poly(L-lactide-co-${\varepsilon}$-caprolactone) (PLCL) nano- and micro-fibrous scaffolds as a unique platform with structural and biological properties with native ECM using electrospinning method and gamma-ray irradiation. Surface morphology of the scaffolds was observed by scanning electron microscopy, and alteration of surface property was evaluated with toluidine blue O staining, water contact angle measurement and ATR-FTIR analysis.