• 폴리머
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• 제33권3호
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• pp.219-223
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• 2009

전기방사 공정을 이용하여 제조된 나노파이버는 나노 소자, 필터, 방호닦, 항균성 드레싱 및 약물전달 등 다양한 분야에서 이용되고 있다. 약물전달시스템(drug delivery system, DDS)은 기존 의약품의 부작용을 최소화하며 그 효능 및 효과를 극대화할 수 있어야 하고 필요한 양의 약물을 원하는 환부에 효율적으로 전달할 수 있어야 한다. 본 연구에서는 전기유체역학공정의 하나인 전기방사공정을 이용하여, poly($\varepsilon$-carprolactone)(PCL) poly(ethylene oxide(PEO)를 나노파이버 매트로 만들었으며, 고분자와 동시 방사된 Rhodamine B의 방출량을 측정하였다. PCL/Rhodamine B/PEO/PCL 나노파이버 매트는 전기방사 시간을 통한 두께 조절을 통하여 약물전달 거동이 조절될 수 있음을 확인하였으며, 실제 Peptide를 PEO와 동시 전기방사시켜 얻어진 나노파이버 peptide가 방출되는 거동을 확인하였다. PCL/Peptide/PEO/PCL시스템에서 방출된 peptide는 약물방출 시험 후에도 약물로서의 활성도를 잃지 않았으며, 이러한 나노파이버를 이용한 Peptide 방출메커니즘은 새로운 약물전달시스템으로 적용 및 응용될 수 있을 것으로 예상된다.

• Macromolecular Research
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• 제11권4호
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• pp.283-290
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• 2003

Organic drugs including aspirin, omeprazole, and naproxen with three different levels of octanol/water partition coefficient were examined for their release behavior from the amphiphilic PCL-b-PEO-b-PCL (PCEC) matrix. Scanning electron micrograph (SEM) of PCEC illustrated a well defined two-phase morphology consisted of dispersed poly(ethylene oxide) (PEO) domain and continuous polycaprolactone (PCL) phase. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) experiments veri tied that three model drugs are dissolved as a molecular dispersion in PCEC matrix. The release of hydrophilic aspirin closely followed the water absorption profile of the matrix indicating that its major fraction is present in PEO domain. However, substantial amount of aspirin present in less hydrophilic region displayed discontinuous biphasic release pattern. In the case of omeprazole with intermediate hydrophobicity consistent release behavior was observed for a period of 24 hrs after the rapid liberation of ca. 10% of the drug presumably partitioned in PEO phase. It was ascribed to the fact that the progressive hydration of PCEC matrix gradually increased the chance of drug/water exposure to compensate the exhaustion of device. Naproxen with the highest octanol/water distribution coefficient among three model drugs exhibited a limited release of 35% for 24 hrs. Finally, hydroxypropyl methylcellulose phthalate (HPMCP)/PCEC blend matrix demonstrated an accelerated and quantitative release of hydrophobic naproxen by generating high porosity and thereby expanding polymer/water interface.

• 폴리머
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• 제37권3호
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• pp.332-341
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• 2013

H-shaped amphiphilic pentablock copolymers $(PSt)_2-b-PCL-b-PEO-b-PCL-b-(PSt)_2$ was synthesized via chemoenzymatic method by combining enzyme-catalyzed ring-opening polymerization (eROP) of ${\varepsilon}$-caprolactone (${\varepsilon}$-CL) and atom transfer radical polymerization (ATRP) of styrene. By this process, we obtained copolymers with controlled molecular weight and low polydispersity. The structure and composition of the obtained copolymers were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) and infrared spectroscopy analysis (IR). The crystallization behavior of the copolymers was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The crystallization behavior of the H-shaped block copolymers demonstrated a PCL dominate crystallization. The self-assembly behavior of the copolymers was investigated in aqueous media. The hydrodynamic diameters of the copolymer micelles in aqueous solution were measured by dynamic light scattering (DLS). The morphology of the copolymer micelles was observed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The hydrodynamic diameters of spherical micelles declined gradually with the increase of the hydrophobic chain lengths of the copolymers. The critical micelle concentration (CMC) values were determined from fluorescence emission, and it was found that the CMCs decreased with an increase of PSt hydrophobic block lengths.