Papers by Author: Jong Chul Park

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Authors: K.O. Park, Jae Bong Choi, Jong Chul Park, D.J. Park, Jeong Koo Kim
Abstract: Polyurethane foam was fabricated by ‘two-component method’ for changing cell structures. Compression force applied immediately to the polyurethane foam just after complete foam formation at the top of the mold for generation cell structure of negative Poisson effect. That is what we called pressure-controlled method. The polyurethane foam, produced by pressurecontrol method (CT), has significant higher resilience (52.3%) and similar level of shock absorption (47.5%) compared with control polyurethane foam (resilience is 21.5%, shock absorption is 54%). The PU foam with negative Poisson’s ratio showed excellent resilience with shock absorbance. The pressure-control method divided into two parts (CT0, CT1). The CT1 method is to apply compression force to the foam with time-delayed after foam formation. The PU foam produced by CT1 showed lower stress relaxation time, stress relaxation ratio, and maximum stress than CT0. Hence, CT1 foam is superior to other polyurethane foam as shock absorbing materials, such as shoes for diabetic patients.
Authors: Mi Hee Lee, Yeon I Woo, In Seop Lee, Jeong Koo Kim, Jong Chul Park
Abstract: Tissue-engineering must be either manufactured aseptically or sterilized after processing. To extend protection of medical devices against microbial contamination, various sterilization methods have been suggested. Hydrogen peroxide gas plasma sterilization has been applied in hospitals worldwide for almost a decade. In this study, we investigated the sterilization efficacy of hydrogen peroxide gas plasma sterilizer with porous polyurethane sample. The result is suggested that hydrogen peroxide gas plasma can be applicable to the sterilization of polymer scaffold for tissue engineering materials.
Authors: Hyun Joo Son, Dong Wook Han, H.H. Kim, Hee Joong Kim, In Seop Lee, Jeong Koo Kim, Jong Chul Park
Abstract: In this study, human dermal fibroblast behaviors onto non-porous PLGA (75:25) films immobilized with 1, 10 and 100 µg/ml collagen (CN) or fibronectin (FN) were investigated according to different cell-seeding densities (1,000, 10,000 and 100,000 cells/ml). Cell attachment and proliferation were assessed using water soluble tetrazolium salt. The results indicated that 1 µg/ml of FN-immobilized PLGA film demonstrated significantly (p < 0.05) superior cellular attachment to the intact PLGA film after 4 hr of incubation. Moreover, the number of attached cells was shown to be directly proportional to that of initially seeded cells. After 48 hr, the cells showed significantly (p < 0.05) higher proliferation onto 1 or 10 µg/ml of FN-immobilized PLGA films than onto other PLGA films, regardless of the initial cell-seeding density. In terms of CN-immobilization, cell proliferation was appreciably increased but it was relatively lower than FN-immobilization. These results suggested that ECM-immobilization can enhance the cell affinity of hydrophobic scaffolds and be used to potential applications for tissue engineering by supporting cell growth.
Authors: B.J. Park, Seok Cheol Kim, D.H. Lee, Hyun Joo Son, K.C. Nam, K. Takatori, M. Aihara, Jong Chul Park
Abstract: In this study, a computer-assisted cell tracking system including an automatic image processing program for rapid and precise analysis of cell migration in various conditions was self-designed and L-929 cell migration on the glass coated with type I collagen was examined using this cell tracking system. Furthermore, computer-based image processing software, with the capture program to choose the capture interval and period, and analysis techniques were developed for quantitative analysis of the cell migration on extracellular matrices. The results showed that the migration speed of L-929 cells on the collagen-coated glass was significantly (p < 0.05) increased compared to the non-coated control. On the morphological observations, it was showed that the cells on the collagen-coated glass looked much healthier than those on the control. These results suggested that this cell tracking system would provide tools for the analysis of cell migration in various in vitro conditions and might be effective enough to evaluate various biological events including embryonic development as well as physiological and pathological tissue reorganization.
Authors: Sang Gil Lee, Jung Bok Lee, Jong Chul Park, Young Il Yang, Jeong Koo Kim
Abstract: The effect of β-glucan-reinforced PLGA scaffold on cell proliferation was investigated. The PLGA scaffolds were prepared by salt-leaching method. The prepared scaffolds were grafted with (1→3) (1→6)-β-glucan in various ratios after plasma treatment on the surface. The surface of the scaffold was characterized by scanning electron microscope (SEM). The HDFs (Human dermal fibroblasts, 1105 cells/scaffold) were used to evaluate the cell proliferation on PLGA scaffold before and after plasma/β-glucan treatment. In results, in the β-glucan treated scaffolds, the pores seemed to become narrower and even looked like closed form. The result of cell proliferation showed that the plasma/β-glucan treated scaffolds had narrower pores because the β-glucan was attached in the pores that would not be allowed the cells to penetrate into the inner areas. Consequently, cell proliferation was not effective in the plasma/β-glucan treated scaffolds in this study.
Authors: Yeon I Woo, Hyun Joo Son, Hye Ryeon Lim, Mi Hee Lee, Hyun Sook Baek, Kazufumi Tsubaki, Jong Chul Park
Abstract: Glucans have been reported to stimulate immunity and to promote wound healing. Adult human dermal fibroblast (aHDF) cultured in serum free (serum-starvation). Proliferation of aHDF was measured at various concentrations of β-glucan by MTT assay, and migration was observed for 36h on microscope. The result of fibroblast bioassay, β-glucan had positive influence. In this study, the direct effects of β-glucan on proliferation and migration of human dermal fibroblasts were examined in vitro. That means β-D-glucan has the effect to enhance proliferation and aHDF migration speed, and has the potential as a wound healing agent.
Authors: In Ho Han, Jai Hyuk Choi, Hong Koo Baik, Jong Chul Park, Jeong Koo Kim, Kwon Yong Lee, S.-M. Chung, In Seop Lee
Abstract: The surface properties of scaffolds are important since cell affinity is the most crucial factor to be concerned when the biodegradable polymeric material is utilized as a scaffold in tissue engineering. The surface of biodegradable non-porous poly (lactic-co-glycolic acid) (PLGA) scaffolds were treated by atmospheric pressure dielectric barrier discharge (APDBD). The wetting angle of APDBD treated PLGA were decreased from the untreated PLGA of 73° to 42°. FTIR-ATR analyses showed hydroxyl groups were not detected regardless of treated condition, but the intensities of both ether groups and carbonyl groups were increased with treatment time and oxygen flow rate. Treatment time and oxygen flux are equally effective to make the PLGA surface more hydrophilic.
Authors: Jin Hyun Chung, Hye Ryeon Lim, Tek Hyung Lee, Mi Hee Lee, Yeon I Woo, Hyun Sook Baek, Seung Jin Lee, Jeong Koo Kim, Jong Chul Park
Abstract: Poly (D,L-latic-co-glycolic acid) (PLGA) has been used as the artificial scaffold for blood vessel formation. In order to hinder smooth muscle cell (SMC) angiogenesis, new scaffold design method of loading Epigallocatechin 3-O-gallate (EGCG) on PLGA film was introduced. PLGA and EGCG were dissolved in acetone and film-shape scaffold was manufactured. Antiangiogenetic effect of EGCG released on scaffold was analyzed for SMC and human umbilical vein endothelial cell (HUVEC) and method for selective inhibition from the difference of growth of SMC and HUVEC was suggested.
Authors: In Seop Lee, J.M. Park, Hyun Joo Son, Jong Chul Park, Geun Hee Lee, Y.H. Lee, Fu Zhai Cui
Abstract: Implantable neural prostheses form hybrid interfaces with biological constructs, and the application of electrical fields can restore functions of patients with neurological damages. The various stoichiometric compositions of iridium oxide were synthesized using reactive magnetron sputtering. The charge injection behavior of iridium oxide deposited with an O2/Ar ratio of 0.5 was similar to pure Ir. The charge density of iridium oxide increased with increasing O2/Ar ratio, and increasing thickness of iridium oxide.
Authors: In Seop Lee, Jong Chul Park, Geun Hee Lee, Won Seon Seo, Yun Hee Lee, Kwon Yong Lee, Jong Kweon Kim, Fu Zhai Cui
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