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Gongneung dong, South Korea

Kim G.,Chosun University | Ahn S.,Chosun University | Kim Y.,Modern Cell and Tissue Technologies Inc. | Cho Y.,Hallym University | Chun W.,Hallym University
Journal of Materials Chemistry | Year: 2011

Collagen is the most promising natural biomaterial and has been used in various tissue engineering applications for skin, bone, and cartilage because it provides good biocompatibility and low antigenicity. Although collagen is an excellent candidate material for various biomedical applications, its difficult processability and mechanical properties have remained important limitations. To overcome the problems, several methods including indirect printing combined with a sacrificing mold and low-temperature printing were suggested. However, it is difficult to fabricate precisely controlled 3D pore structure using the methods. In a previous study, we introduced a three-dimensional (3D) pore-structure-controlled collagen scaffold fabricated by a 3D dispensing system supplemented with a cryogenic and freeze-drying system. The fabricated scaffold had remarkably good cellular behaviour (cell migration and differentiation) but poor mechanical stability due to the highly porous structure consisting of micro-sized strands and poor mechanical nature of collagen. To overcome this deficiency, we designed a hybrid (core/shell) scaffold composed of an outer collagen and an inner alginate. The collagen/alginate scaffolds exhibited good structural stability (core-shell structure), increased Young's modulus about seven times compared to pure collagen scaffold under a similar pore-structure, and resulted in good cell viability, similar to a pure collagen scaffold. In an in vivo test, the hybrid scaffold was used as a dermal substitute and provided good granulation tissue formation and rapid vascularisation. © 2011 The Royal Society of Chemistry. Source


Kim G.H.,Chosun University | Ahn S.H.,Chosun University | Lee H.J.,Chosun University | Lee S.,Modern Cell and Tissue Technologies Inc. | And 2 more authors.
Journal of Materials Chemistry | Year: 2011

Biomedical scaffolds have been widely used to regenerate various tissues and organs. One technology used for scaffold fabrication is rapid prototyping (RP), which has the advantage of easy control of the internal microstructure of scaffolds. However, scaffolds fabricated using RP technology show low resolution of struts and too smooth struts, which can deteriorate initial cell attachment and proliferation. To overcome this problem, we propose a hybrid technology combining a RP system and electrohydrodynamic (EHD) direct writing, which has been used to generate highly roughened microsized threads for enhanced cellular behavior with controllable mechanical properties. The resulting structure consists of alternating layers of microsized struts and highly roughened threads. The results of culturing osteoblast-like cells show significantly enhanced biological properties of the scaffold (approximately 2 times the cell viability and 2.5 times the bone mineralization) compared to the scaffolds fabricated using RP technology, and we believe that the combined process can be a promising method for fabricating three-dimensional biomedical scaffolds in soft and hard tissue regeneration. © 2011 The Royal Society of Chemistry. Source


Trademark
Modern Cell and Tissue Technologies Inc. | Date: 2009-09-22

Biological preparations for pharmaceutical purposes, Pharmaceutical preparations for use in cell therapy of wounded skin, Biological skin tissue intended for subsequent implantation, Pharmaceutical preparations for skin regeneration, Pharmaceutical preparations for the treatment of burns, Pharmaceutical preparations for the treatment of skin ulcers. Artificial skin for testing safety and efficacy of pharmaceutics, Artificial skin for testing safety and efficacy of cosmetics, Artificial skin for research of skin carcinogenesis, Artificial skin for testing inflammatory agents, Artificial skin for testing potential irritants, Artificial skin for testing potential allergens, Artificial skin for testing skin whitening agents, Artificial skin for testing transdermal absorption of pharmaceutics. Artificial skin for surgical purposes, Artificial skin for the replacement of skin.


Trademark
Modern Cell and Tissue Technologies Inc. | Date: 2009-09-29

Biological preparations for pharmaceutical purposes, Pharmaceutical preparations for use in cell therapy of wounded skin, Biological skin tissue intended for subsequent implantation, Pharmaceutical preparations for skin regeneration, Pharmaceutical preparations for the treatment of burns, Pharmaceutical preparations for the treatment of skin ulcers. Artificial skin for testing safety and efficacy of pharmaceutics, Artificial skin for testing safety and efficacy of cosmetics, Artificial skin for research of skin carcinogenesis, Artificial skin for testing inflammatory agents, Artificial skin for testing potential irritants, Artificial skin for testing potential allergens, Artificial skin for testing skin whitening agents, Artificial skin for testing transdermal absorption of pharmaceutics. Artificial skin for surgical purposes, Artificial skin for the replacement of skin.


Lee J.,Modern Cell and Tissue Technologies Inc. | Choi Y.-J.,Modern Cell and Tissue Technologies Inc. | Kim C.H.,Korea Institute of Radiological and Medical Sciences | Kim H.-Y.,Konkuk University | Son Y.,Kyung Hee University
Tissue Engineering and Regenerative Medicine | Year: 2011

In this study, we evaluated the accessibility of chitosan-based scaffold for tissue-engineered hyaline cartilage (TEHC) in vitro and in vivo using costal chondrocytes (CCs) as an alternative donor source. Acetylated chitosan scaffold (ACS) was prepared by the treatment of the porous chitosan scaffold (CS) with acetic anhydride. After acetylation of CS, the structural integrity and porosity were maintained but the strength of the scaffold was reduced and the dissolubility was increased. To evaluate the effectiveness of ACS as a scaffold for TEHC, ASCs with or without hyaluronic acid (HA) coating and commercial collagen scaffold (COL) as a control were used for cartilage reconstruction in vitro. In three-dimensional culture within sponge-form scaffolds, CCs re-differentiated to hyaline cartilage-like constructs, which were featured by GAG, type II collagen expression and lacunae-like structure. In contrast to no infiltration of inoculated CCs in the COL, extensive infiltration of CCs to the inner part of the scaffold was observed in ACSs with or without hyaluronic acid coating. For the in vivo evaluation of TEHC in the capacity to repair osteochondral defects, TEHC was transplanted to the full thickness cartilage defects made on the patellar grove of rabbit knee and was evaluated by immunohistological examination and Wakitani's histological scoring method of the regenerative tissues. TEHC successfully restored hyaline type cartilage and subchondral bone as well, in contrast to the fibrocartilage formation in the untreated control. In conclusion, ACSs serve a scaffold for the reconstruction of hyaline cartilage by inoculated CCs in vitro and also for the repair of osteochondral defect on the articular cartilage in vivo. Source

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