[Evaluation of differentiation potential of human bone marrow-derived mesenchymal stromal cells to cartilage and bone cells].

OBJECTIVES: This study was designed to identify the characteristics and surface antigen properties of mesenchymal stromal cells (MSC) isolated and cultured from bone marrow of healthy subjects and to assess their differentiation potential to osteoblast and chondroblast lineage cells.

METHODS: Mononuclear cells were isolated by density-gradient separation from 1-3 ml of bone marrow collected from 10 donors of bone transplantation aged between 4 months and 18 years. These mononuclear cells were cultured in flasks containing 10% fetal calf serum, which resulted in growth of fibroblast-like cells showing adhesion onto the culture flask. Physical properties of the cells were identified and flow cytometric immunophenotyping was performed to specify surface antigen properties. Differentiation of mesenchymal stromal cells in specific media to chondroblasts and osteoblasts was evaluated. Osteoblasts and chondroblasts were stained with Alizarin red and Alcian blue, respectively, and microphotographed.

RESULTS: In vitro yield of MSCs showed no age-related differences in terms of morphological and adhesive properties. While cells of stromal origin showed strong positivity (90% to 99%) to characteristic CD105, CD44, CD166, CD29, CD90, and CD73 antibodies, hematopoietic cells remained negative (0% to 5%) to CD45, CD34, CD14, and HLA-DR antibodies. It was observed that MSCs produced in cell-specific media differentiated to osteoblasts and chondroblasts in all passages (p1-15) tested, including late passages.

CONCLUSION: It seems that the use of MSCs would provide promising treatment strategies in bone marrow transplantation, inherited diseases, and organ repair; in in vitro assessment of biological effects of biomaterials in orthopedics; and in repair of bone and cartilage injuries.