Osteogenic Differentiation of Human Mesenchymal Stem Cells: Effects of the compositions of biodegradable polymers and the initial cell-seeding density / 대한정형외과학회잡지

PURPOSE: To investigate the effects of initial cell-seeding density and the compositions of biodegradable polymer scaffolds on the osteogenic differentiation of human mesenchymal stem cells. MATERIALS AND METHODS: Human mesenchymal stem cells (hBMSCs) were cultured three-dimensionally onto biodegradable polymers with three different compositions (65/35 PLGA, 85/15 PLGA, PLLA), and osteogenic differentiation was studied by; histology, immuno-histochemistry, and transmision/scanning electron microscopy. RESULTS: In terms of the amount of extracellular matrix (ECM) produced, the 65/35 PLGA (23% of the whole volume) was found to produce more ECM than 85/15 PLGA (21%) and PLLA (13%). Osteoblastic differentiation of hBMSCs was induced in all scaffolds examined and the deposition of ECM with calcifications started after 2 weeks of culture. The amount of calcium deposited on the 65/35 PLGA dramatically increased at 4 weeks. On comparing low cell-seeding density with the high cell-seeding density on 65/35 PLGA, calcium deposits reached similar levels at 6 weeks. CONCLUSION: Three-dimensional culture of hBMSCs on biodegrable polymer scaffolds induced bone formation, which was dependent on the compositions of the scaffolds and the initial cell-seeding density.

Tissue-engineered reconstitution of oral mucosa using polydioxanone mesh

The lack of sufficient oral mucosa available for intra-oral reconstruction has been dealt with by the use of skin or oral mucosa grafts harvested from donor sites but grafts requires more than one surgical procedures and could cause donor site morbidity. Many investigators have attempted to increase available soft tissue by tissue engineered skin or oral mucosa replacements for clinical applications. But, reconstructed mucosa by several methods have low physical properties such as rolling and contraction. The aims of this study were to develope an in vitro experimental model that maintains an epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally cultured oral mucosa embedded with Polydioxanone mesh by histological and immunohistochemical analysis. The results were as follows; 1. Oral mucosa reconstructed by three-dimensional organotypic culture revealed similar morphologic characteristics to equvalent normal oral mucosa in the point that they show stratification and differentiation. 2. The expression of cytokeratin 10/13 and involucrin in the cultured tissue showed the same pattern with normal oral mucosa suggesting that organotypic co-culture condition is able to induce cellular differentiation. 3. After insertion of polydioxanone mesh, increased tensile strength were observed. These results suggest that three-dimensional organotypic co-culture of the oral mucosa cell lines with the dermal equvalent consisting type I collagen and fibroblasts reproduce the morphologic and immunohistochemical characteristics similar to those in vivo condition. And increased physical properties by use of polydioxanone mesh will helpful for clinical applications.