A Minimal Common Osteochondrocytic Differentiation Medium for the Osteogenic and Chondrogenic Differentiation of Bone Marrow Stromal Cells in the Construction of Osteochondral Graft

To regenerate the complex tissue such as bone-cartilage construct using tissue engineering approach, controllable differentiation of bone marrow stromal cells (BMSCs) into chondrogenic and osteogenic lineages is crucially important. This study proposes to test a minimum common osteochondrocytic differentiation medium (MCDM) formulated by including common soluble supplements (dexamethasone and ascorbic acid) used to induce chondrogenic and osteogenic differentiation. The MCDM coupled with supplemented growth factors was tested for its ability to differentiate BMSCs into osteogenic and chondrogenic lineages in both two-dimensional and three-dimensional culture systems. When transforming growth factor beta 3 was added to MCDM, BMSCs differentiated to chondrocyte-like cells, evidenced by the expression of glycosaminoglycans and type II collagen, whereas osteogenic differentiation was induced by supplementing osteogenic protein-1, resulting in detectable expression of osteopontin and osteocalcin. These chondrogenic and osteogenic differentiation markers were significantly enhanced in the three-dimensional cultures compared to the two-dimensional monolayer cultures. The results achieved in this study lay a foundation for future development of osteochondral graft, which could be engineered from bilayered scaffold with spatially loaded growth factors to control BMSC differentiation.