In vitro chondrogenic phenotype differentiation of bone marrow-derived mesenchymal stem cells.

In order to study the chondrogenic phenotype differentiation of adult sheep bone marrow-derived mesenchymal stem cells (MSCs) in a defined medium as potential seed cells for cartilage tissue engineering. MSCs were isolated by density centrifugation with Percoll solution from bone marrow aspirated from sheep iliac crest. The third passage of MSCs were induced with H-DMEM containing TGF-beta3, IGF-I, Dexamethasone and VitC. The shape and ultrastructure of cells were observed, toluidine blue stain for GAG and immunohistochemistry for type II collagen were applied for chondrogenic phenotype identification. After 14 days of induction, MSCs changed from a spindle-like appearance to a polynal shape, a large amount of endoplasmic reticulum, Golgi complex and mitochondria were observed, and the differentiation of MSCs chondrogenic phenotype was verified by positive staining of toluidine blue and immunohistochemistry. MSCs derived from bone marrow can differentiate to chondrogenic phenotype when induced in vitro and can be used as optimal seed cells for cartilage tissue engineering.