• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.379-380
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• 2002

기계적 성질이 우수한 PVC와 생분해성이 우수한 고분자로 알려져 있는 폴리카프로락톤 (PCL)과 블렌드하여 새로운 소재의 생분해성 필름을 제조하여 생분해성 효과에 대해 조사하였으며, 그 결과 PCL/PVC 필름의 표면은 8주 후에 다수의 작은 구멍이 형성되었으며, 이러한 결과는 PCL의 함량이 9%로 낮아도 생분해성을 지닌다는 것을 의미한다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2001년도 가을 학술발표회 논문집
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• pp.440-443
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• 2001

Polymer/layered silicate nanocomposites have recently received considerable attention from both academia and industry as an effective way to overcome the shortcomings of conventional polymer. When the silicate layers are exfoliated and randomly distributed in polymer matrix, the nanocomposites exhibit improved mechanical, thermal and barrier properties. (omitted)

• 한국임상수의학회지
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• 제32권3호
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• pp.224-230
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• 2015

본 연구는 키토산 알지네이트 수화겔을 사용하여 제작된 연골세포의 3차원 구조를 유지하며 생물학적, 생리학적인 기능을 유지하는데 적합한 poly (L-Lactic-co-${\varepsilon}$-Caprolactone) (PLCL) 지지체의 효과에 대한 연구이다. 체내에서 수화겔은 단독으로 지지체 역할을 하기에는 부하를 견디기에 약하다. 이에 본 연구에서는 연골세포와 유사한 세포, 세포외 기질의 3차원적 구성을 만들기 위해 PLCL 지지체와 수화겔을 사용하여 합성 지지체를 제작하였다. 염화나트륨을 사용한 입자 침출 기법으로 85%의 다공성, $300-500{\mu}m$ 크기의 구멍을 가진 탄성력 높은 지지체를 제작하였다. 소의 연골세포와 키토산 알지네이트 겔 혼합물이 PLCL 지지체에 적용되었고 대조군의 알지네이트와 비교 연구하였다. 키토산 알지네이트 수화겔과 연골세포가 혼합된 경우에 알지네이트 단독 사용에 비해 세포 성숙, 증식, 세포외 기질의 합성, sGAG 생성과 II 형 콜라겐의 발현 등의 효과가 좋은 것으로 확인되었다. 본 연구 결과를 통해 PLCL 지지체에 연골세포와 키토산 알지네이트 겔 혼합물을 적용할 경우 세포 증식과 기질의 합성에 적합한 환경을 만들 수 있으며 연골의 복구와 재생에 효과적으로 사용될 수 있을 것으로 기대된다.

• 폴리머
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• 제36권2호
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• pp.124-130
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• 2012

본 연구의 목적은 전기방사법을 사용하여 poly(L-lactide-$co$-${\varepsilon}$-caprolactone) (PLCL)과 marine collagen (MC)이 혼합된 나노섬유를 제조하는 것이다. 전기방사된 나노섬유의 직경과 형태는 여러 공정 변수에 의해서 변화되는데, PLCL과 MC의 혼합비, 노즐과 콜렉터와의 거리, 노즐의 직경, 용액의 방출 속도 그리고 전기장의 세기 변화에 따라 나노파이버의 직경을 주사전자현미경을 통해서 분석하였다. 또한 제조된 나노파이버의 표면변화를 확인하기 위해 물과의 접촉각을 측정하였으며, 나노파이버의 세포 친화성을 평가하기 위해 MG-63을 이용하여 생존율과 흡착형태를 주사전자현미경과 형광현미경을 통해서 관찰하였다. 이와 같은 연구 결과, 방사거리, MC의 함량, 전기장의 세기가 증가할수록 제조된 나노파이버의 평균직경은 감소하는 경향을 나타냈다. 또한 MC의 함량이 증가할수록 나노파이버의 친수성이 증가하였고 세포독성은 관찰되지 않았다. 이에 따라 해양유래 생물에서 추출한 콜라겐은 조직공학용 소재에 새롭게 사용될 수 있을 것으로 예상된다.

• 폴리머
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• 제38권4호
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• pp.477-483
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• 2014

Poly(lactic acid) (PLA) and poly(${\varepsilon}$-caprolactone) (PCL) blends with various components for melt-blown non-wovens were prepared by a twin-screw extruder. Tributyl citrate (TBC) was added in order to improve the miscibility between PLA and PCL. The results showed that small circular particles of PCL were dispersed in PLA matrix uniformly. The addition of PCL had the heterogeneous nucleation effect on the crystallization of PLA and decreased thermal stability of PLA. The flow of pure PLA and blends approached to Newtonian liquid at a low shear rate and expressed more obvious viscoelasticity at a high shear rate.

• Archives of Pharmacal Research
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• 제26권1호
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• pp.76-82
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• 2003

Drug releasing porous poly($\varepsilon$-caprolactone) (PCL)-chitosan matrices were fabricated for bone regenerative therapy. Porous matrices made of biodegradable polymers have been playing a crucial role as bone substitutes and as tissue-engineered scaffolds in bone regenerative therapy. The matrices provided mechanical support for the developing tissue and enhanced tissue formation by releasing active agent in controlled manner. Chitosan was employed to enhance hydrophilicity and biocompatibility of the PCL matrices. PDGF-BB was incorporated into PCL-chitosan matrices to induce enhanced bone regeneration efficacy. PCL-chitosan matrices retained a porous structure with a 100-200 $\mu$m pore diameter that was suitable for cellular migration and osteoid ingrowth. $NaHCO_3$ as a porogen was incorporated 5% ratio to polymer weight to form highly porous scaffolds. PDGF-BB was released from PCL-chitosan matrices maintaining therapeutic concentration for 4 week. High osteoblasts attachment level and proliferation was observed from PCL-chitosan matrices. Scanning electron microscopic examination indicated that cultured osteoblasts showed round form and spread pseudopods after 1 day and showed broad cytoplasmic extension after 14 days. PCL-chitosan matrices promoted bone regeneration and PDGF-BB loaded matrices obtained enhanced bone formation in rat calvarial defect. These results suggested that the PDGF-BB releasing PCL-chitosan porous matrices may be potentially used as tissue engineering scaffolds or bone substitutes with high bone regenerative efficacy.

• Advanced Composite Materials
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• 제17권2호
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• pp.157-166
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• 2008

In this study, multiwalled carbon nanotubes (MWCNTs) were compounded with the poly($\varepsilon$-caprolactone) (PCL) matrix at the solution state using chloroform. For homogeneous dispersion of MWCNTs in polymer matrix, oxygen-containing groups were introduced on the surface of MWCNTs. The mechanical properties of the PCL/MWCNTs composites were effectively increased due to the incorporation of MWCNTs. The composites were characterized using scanning electron microscopy in order to obtain information on the dispersion of MWCNT in the polymeric matrix. In case of 1.2 wt% of MWCNTs in the matrix, strength and modulus of the composite increased by 12.1% and 164.3%, respectively. In addition, the dispersion of MWCNTs in the PCL matrix resulted in substantial decrease of the electrical resistivity of the composites as the MWCNTs loading was increased from 0 to 2.0 wt%. Furthermore, thermal stability of the PCL and PCL/MWCNTs-COOH composites were investigated using the data acquired from the thermogravimetric analysis. The detailed kinetics of the thermal degradation of the composites was investigated by analyzing their thermal behavior at different heating rates in a nitrogen atmosphere. Activation energy of thermal degradation was determined by using the equations proposed by Kissinger and Flynn-Wall-Ozawa. The apparent activation energy of PCL/MWCNTs-COOH composite was considerably higher than that of neat PCL.

• 폴리머
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• 제31권2호
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• pp.153-159
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• 2007

생분해성 분자 날인 고분자는 바이오센서 약물 전달 등의 생의학적 분야에 적응이 가능하다. 그러므로, 본 연구에서는 생분해성 고분자인 $poly(\varepsilon-caprolactone)$ (PCL) 매크로머를 가교제로 사용하여 theophylline 분자 날인 고분자를 광중합을 통해 제조하고 물성을 조사하였다. PCL 매크로머는 말단에 아크릴기를 갖도록 합성하였으며 FT-IR과 $^1H-NMR$로 확인하였다. PCL 매크로머의 합성수율은 약 78 mol%였다. Theophylline의 제거 및 재결합 실험은 UV/Vis분광기를 이용하여 용액 내 theophylline의 농도를 확인함으로써 이루어졌다. Theophylline분자 날인 고분자의 생분해성 실험을 $37^{\circ}C$의 PBS 용액 내에서 진행한 결과 우수한 생분해성을 보였다.

• Fibers and Polymers
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• 제6권1호
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• pp.13-18
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• 2005

PLA/LPCL/HPCL blend fibers composed of poly (lactic acid) (PLA), low molecular weight poly ($\varepsilon$-caprolactone) (LPCL), and high molecular weight poly ($\varepsilon$-caprolactone) (HPCL) were prepared by melt blending and spinning for bioab­sorbable filament sutures. The effects of blending time and blend composition on the X-ray diffraction patterns and tensile properties of PLA/LPCL/HPCL blend fibers were characterized by WAXD and UTM. In addition, the effect of in vitro degra­dation on the weight loss and tensile properties of the blend fibers hydrolyzed during immersion in a phosphate buffer solu­tion at pH 7.4 and 37$^{\circ}C$ for 1-8 weeks was investigated. The peak intensities of PLA/LPCL/HPCL blend fibers in X-ray diffraction patterns decreased with an increase of blending time and LPCL contents in the blend fibers. The weight loss of PLA/LPCL/HPCL blend fibers increased with an increase of blending time, LPCL contents, and hydrolysis time while the tensile strength and modulus of the blend fibers decreased. The tensile strength and modulus of the blend fibers were also found to be increased with an increase of HPCL contents in the blend fibers. The optimum conditions to prepare PLA/LPCL/HPCL blend fibers for bioabsorbable sutures are LPCL contents of $5 wt\%, HPCL contents of $35 wt\%, and blending time of 30 min. The strength retention of the PLA/LPCL/HPCL blend fiber prepared under optimum conditions was about $93.5\% even at hydrolysis time of 2 weeks.

• Macromolecular Research
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• 제17권8호
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• pp.575-579
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• 2009

Copolymerization of L-lactide and s-caprolactone initiated by tin (II) octoate (Sn(Oct)$_2$) was carried out in supercritical chlorodifluoromethane (R22) with varying reaction conditions (time and temperature) and amounts of monomer and catalyst, under a pressure of 250 bar. The optimum conditions were a reaction time of 10 h and a temperature of 130 $^{\circ}C$, which is similar to the temperature used in bulk copolymerization system. The conversion increased from 56% to 76% by increasing the reaction time from 1 to 10 h. The molecular weight also increased to 75,900 g.mol$^{-1}$ over the same period, while the increased monomer concentration resulted in a high molecular weight of 86,400 g.mol$^{-1}$ and a monomer conversion of 84%. Raising the reaction temperature from 90 to 130 $^{\circ}C$ increased the monomer conversion as well as the poly-L-lactide-co-${\varepsilon}$-caprolactone (PLCL) molecular weight. The variation on the stannous octoate catalyst suggested that less catalyst would decrease the caprolactone content of the polymer.