[Study of inducing bone marrow-derived mesenchymal stem cells into chondrocytes in vitro].

Objective:To explore a method of isolation,culture and chondrogenic phenotype differentiation of mesenchymal stem cells(MSCs) from the bone marrow of rats in vitro and to offer experimental reference for the resources of seeding cells in cartilage tissue engineering. Methods:MSCs were isolated from bone marrow and purified by density gradient centrifuge and cultured in vitro. The MSC adherence formed and those in passage 3 were chosen to induce into chondrogenic differentiation. After 7,14,21 days,immunohistochemical techique was applied to detect the expression of collagen typeⅡ. The differentiated cells were implanted on the CPP/PLLA composites. After the cell-scaffold complex was cultured in vitro for one week,the ultrastructure of the scaffold was observed with scanning electron microscopy. Results:The differentiated cells changed from a spindle-like fibroblastic appearance to a polygonal shape,the capability of proliferation was down markedly. Immunohistochemical staining of collagen II were positive for the pass age,especially in the 21st days. Induced MSCs were well adherent to the scaffold composites and the cells were embedded by the cell-matrix. Conclusion:Under the induced medium,MSCs can differentiate into chondrogenic phenotype and secrete specificity matrix of cartilage in vitro. MSCs can likely be served as optimal cell source for cartilage tissue engineering.