• Polymer(Korea)
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• v.36 no.4
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• pp.420-426
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• 2012

In this study, we prepared polymer micelles containing quercetin and rutin, known as antioxidants, using poly(${\varepsilon}$-caprolactone)-b-poly(ethylene glycol), and evaluated in vitro skin permeation of the active materials. Quercetin and rutin loaded micelles were characterized by DSC (differential scanning calorimetry), HPLC (high performance liquid chromatography) and DLS (dynamic light scattering) measurements. The particle size of the polymer micelles increased in a concentration dependent manner (0.5~2.0% PCL-b-PEG). The Zeta potential of quercetin and rutin loaded micelles remained constant. To evaluate the skin penetration of PCL-b-PEG micelles, Franz diffusion cell experiment was performed. The aqueous solutions of quercetin and rutin were used as the control groups. Quercetin and rutin loaded PCL-b-PEG micelles showed more efficient skin permeation than the control groups. Safety assessment (patch test) of quercetin and rutin loaded PCL-b-PEG micelles on skin was performed to test application possibility of the polymer micelles to cosmetics. Any adverse symptoms were not observed.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.28-36
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• 2011

Diblock copolymers composed of poly(${\varepsilon}$-caprolactone) (PCL) and poly(N,N-dimethylamino-2-ethyl methacrylate) (PDMAEMA), or methoxy polyethylene glycol(PEG), were synthesized via a combination of ring-opening polymerization and atom-transfer radical polymerization in order to prepare polymeric nanoparticles as an antifungal drug carrier. Amphotericin B (AmB), a natural antibiotic, was incorporated into the polymeric nanoparticles. The physical properties of AmB-incorporated polymeric nanoparticles with PCL-b-PDMAEMA and PCL-b-PEG were studied in relation to morphology and particle size. In the aggregation state study, AmB-incorporated PCL-b- PDMAEMA nanoparticles exhibited a monomeric state pattern of free AmB, whereas AmB-incorporated PCL-b- PEG nanoparticles displayed an aggregated pattern. In in vitro hemolysis tests with human red blood cells, AmBincorporated PCL-b-PDMAEMA nanoparticles were seen to be 10 times less cytotoxic than free AmB (5 ${\mu}g$/ml). In addition, an improved antifungal activity of AmBincorporated polymeric nanoparticles was observed through antifungal activity tests using Candida albicans, whereas polymeric nanoparticles themselves were seen not to affect activity. Finally, in vitro AmB release studies were conducted, proving the potential of AmB-incorporated PCL-b-PDMAEMA nanoparticles as a new formulation candidate for AmB.

• Journal of Pharmaceutical Investigation
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• v.38 no.3
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• pp.163-169
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• 2008

Liposomes are spherical vesicles composed of lipid bilayer membranes. However, the conventional liposomes have been found to be plagued by rapid opsonization and taken up by the reticuloendothelial system (RES), resulting in shortened circulation time and limited intracellular uptake to target cell. In this study, polyethyleneglycol-cationic liposomes (PCL) containing cationic lipid and DSPE-mPEG were prepared by thin film cast-hydration method. The PEG liposomes had approximately $97.0{\pm}1.3\;nm$ of mean particle diameter and $-21.7{\pm}1.2\;mV$ of zeta potential value. PCL had $96.4{\pm}1.8\;nm$ of mean particle diameter and $-8.7{\pm}1.1\;mV$ of zeta potential value with a decrease of about 10 mV compared to the PEG liposomes. Loading of model drug, doxorubicin (DOX), in liposomes were carried out by using remote loading method and the loading efficiency of DOX in liposomes was about $95.0{\pm}1.9%$. Intracellular uptake and cytotoxicity of PCL were higher than that of PEG liposomes to murine B16F10 melanoma cells. In addition, anti-tumor activity of PCL was similar to that of PEG liposomes on growth of A549 human lung carcinoma in BALB/c mice. Consequently, PCL modified with cationic lipid may be applicable as anticancer drug carriers that can increase intracellular uptake and therapeutic efficacy.

• Polymer(Korea)
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• v.28 no.3
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• pp.232-238
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• 2004

MPEG-PCL diblock copolymers consisting of methoxy poly(ethylene glycol) (MPEG) and $\varepsilon$-caprolactone (CL) as drug carriers were synthesized by ring-opening polymerization MPEG-PCL diblock copolymers were characterized by X-ray diffraction and differential scanning calorimetry. After freeze milling of block copolymers and albumin bovine-fluorescein isothiocyanate (FITC-BSA) as model protein, the wafers loaded FITC-BSA were fabricated by direct compression method. The release profiles of FITC-BSA were examined using pH 7.4 PBS for 14 days at 37$^{\circ}C$. The release amount was determined by fluorescence intensity by using the fluorescence spectrophotometer. The morphological change of wafers was observed by digital camera and scanning electron microscope. The release rate and initial burst of BSA increased with increasing PEG molecular weights and decreasing PCL molecular weights in the segments of MPEG -PCL diblock copolymers.

• Macromolecular Research
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• v.15 no.7
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• pp.623-632
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• 2007

Thermosensitive nanoparticles were prepared via the self-assembly of two different $poly({\varepsilon}-caprolactone)$-based block copolymers of poly(N-isopropylacrylamide)-b-$poly({\varepsilon}-caprolactone)$ (PNPCL) and poly(ethylene glycol)-b-$poly({\varepsilon}-caprolactone)$ (PEGCL). The self-aggregation and thermosensitive behaviors of the mixed nanoparticles were investigated using $^1H-NMR$, turbidimetry, differential scanning microcalorimetry (micro-DSC), dynamic light scattering (DLS), and fluorescence spectroscopy. The copolymer mixtures (mixed nanoparticles, M1-M5, with different PNPCL content) formed nano-sized self-aggregates in an aqueous environment via the intra- and/or intermolecular association of hydrophobic PCL chains. The microscopic investigation of the mixed nanoparticles showed that the critical aggregation concentration (cac), the partition equilibrium constants $(K_v)$ of pyrene, and the aggregation number of PCL chains per one hydrophobic microdomain varied in accordance with the compositions of the mixed nanoparticles. Furthermore, the PNPCL harboring mixed nanoparticles evidenced phase transition behavior, originated by coil to the globule transition of PNiPAAm block upon heating, thereby resulting in the turbidity change, endothermic heat exchange, and particle size reduction upon heating. The drug release tests showed that the formation of the thermosensitive hydrogel layer enhanced the sustained drug release patterns by functioning as an additional diffusion barrier.