Papers by Author: Ik Chan Kwon

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Authors: Sung Won Kim, Yun Sik Nam, Yeon Jin Min, Jong Ho Kim, Kwang Meyong Kim, Kui Won Choi, In Sup Noh, Ik Chan Kwon
Abstract: Stability and disintegration of natural polyelectrolyte complex microspheres for protein drugs delivery have been extensively investigated because of their great influence on the drug release patterns. In this study, we tested stability of microspheres with alginate (Alg) core layered by either chitosan (Chi) or glycol chitosan (GChi) by examining release profiles of fluorophorelabeled bovine serum albumin (BSA) and lysozyme (Lys) from the microspheres. While GChi shell was disintegrated quickly, Chi-shell microspheres showed good stability in PBS. Disintegration of the coated layer induced the core material instable. The results indicated that while the charges of the shell material provided additional diffusion barrier against the protein release, the key factor to hold the proteins inside the microspheres was the integrity of the outer coating layer.
Authors: Moon Kyu Lee, Chang Yang Lee, Dong Ryul Kim, Ik Chan Kwon, Kui Won Choi
Abstract: The purpose of the present study was to develop a polymer film loaded with drug to effectively prevent pin tract infection. It was found that the polymer, poly ethylene-co-vinyl acetate blended with tetrahydrofuran, showed better flexibility and deformability than the other polymers: poly caprolactone18 and poly caprolactone44. Polymer films, poly ethylene-co-vinyl acetate, were divided into five testing groups dependent on the loading concentration of rifampici (5, 10, 15, and 20 wt %). The surface morphology of polymer films was examined by a scanning electron microscopy. It was found that the concentration of drug was a main factor to determine the roughness of the film. Considering the roughness of polymer films, 5 wt % of rifampicin might be the maximum concentration for further applications. Hence, the antibiotic drug-loaded polymer films were manufactured by mixing poly(ethylene-co-vinylacetate) and tetrahydrofuran with rifampicin(antibiotic drug). The film cast was designed as a shape of disk (inner Ø5mm and outer Ø20mm) to be suitable for pins for external fixation in orhtopaedics. The drug-loaded polymer solvent, the amount of 0.6cc, was molded into the disk-shaped film and dried into a airtight box at 15°C for 24 hrs. The drug release characteristics(1, 2, 3, 4 and 5 wt%) were examined as a function of soaking time in phosphate buffered saline (PBS, 10 ml) using an enzyme-linked immunosorbent assay. Rifampicin was linearly released for first 100 hrs(~4 days) for all antibiotic drug-loaded polymer films. Afterward, the drug was released at a slower pace as a function of square root of time until 1000 hrs (~40 days). This slow drug release can be explained by their hydrophobic characteristics of poly ethylene-co-vinyl acetate and rifampicin. The antibiotic drug-loaded polymer film can be intrinsically able to prevent the bacteria adhesion by wrapping the pin track area, and perform active and effective infection-resistant by a sustained antibiotic-release.
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