Papers by Author: In Seop Lee

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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.
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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.
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Authors: In Ho Han, Jai Hyuk Choi, Bao Hong Zhao, Hong Koo Baik, In Seop Lee
Abstract: The surface morphology of commercially pure titanium was investigated with varying electrical waveform. Controlling of electrical pulse width is effective to change pore sizes. Longer electrical pulse width was induced, larger size of pores were generated.
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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.
425
Authors: Dong Hwan Kim, Soon Ho Kwon, Seong Hyeon Hong, Hyoun Ee Kim, In Seop Lee, Young Chul Jung
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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.
307
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
805
Authors: Bao Hong Zhao, Hai Lan Feng, Xiao Dan Sun, Fu Zhai Cui, In Seop Lee
Abstract: A part of the titanium dental implant surface, which will meet connective tissue after being inserted in mandibular bone, was coated with calcium phosphate by ion beam assisted deposition (IBAD). Twenty-four implants of coated and uncoated group were randomly placed in mandibles after 3 months of premolars extraction in beagle dogs. All the implants were firmly anchored in the bone and had no clinical signs of peri-implant inflammation after 3-month insertion. The probing depth in calcium phosphate coated group is 1.9±0.2 mm, less than in control group (2.1±0.2 mm) (p<0.05). Most of the probing sites tended to bleed upon probing in two groups. It might indicate that the calcium phosphate coating has the potential to promote soft tissue integration.
751
Authors: M.K. Kim, Jung Yoo Choi, Ui Won Jung, In Seop Lee, T. Inoue, Seong Ho Choi
Abstract: The aim of this study is to evaluate the effects of coating implants with hydroxyapatite (HA) by an ion beam-assisted deposition (IBAD) method and to compare them with implants prepared with machined and anodized surfaces. Twenty-four implants in this study were divided into three groups; machined, anodized, anodized plus IBAD surface implants. Implant stability and osseointegration were assessed by resonance frequency analysis (RFA) and histologic analysis. We can conclude that implants coated by HA by IBAD demonstrate characteristics of contact osteogenesis, but the research design does not permit conclusions regarding long-term treatment outcome with implants. Further studies are needed.
597
Authors: Dong Joo Lee, In Seop Lee
Abstract: The hygrothermal degradation of glass fiber/nylon composite was investigated after aged at 25°C, 50°C, 75°C and 100°C up to 1 month of total exposure in aqueous solution. The effects of moisture absorption and thermal aging on mechanical properties are compared as functions of temperature, fiber volume and concentration of sodium chloride. The amount of water absorption increases when the aging temperature is increased and the concentration of NaCl is lowered. In general, the mechanical properties decrease with amount of water absorption. The degradation rate of various mechanical properties is different depending on the temperature, fiber volume and the concentration of NaCl. The diffusion mechanisms of water in short-fiber reinforced nylon are discussed as functions of fiber volume, molding conditions and concentration of sodium chloride.
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