Study On Differentiation Into Chondrocytes Of Human Bone Marrow Mesenchymal Stem Cells In Vitro

Aim To isolate, culture, and multiply mesenchymal stem cells (MSCs) from human bone marrow aspiration, then induce MSCs with special culture medium and detect the expression of collagen type II of chondrocyte with semiquantitative RT-PCR analysis to explore the possibity of its differentiation into chondrocytes in vitro. That will give a new support for using of MSCs in cartilage engineering and theraping the functional disorder or deficiency of chondrocytes.Methods: Bone marrow aspiration samples were obtained from 8 adult human donors 28 to 65 years old without severe hematopietic and genetic diseases. They were diluted to five folds in conventional culture medium (DMEM supplemented with 10% fetal bovine serum ) and centrifugated 5 minutes at 2000rpm. Discarded the supernatant and fat layer, the remain layer of solution that contains mononuclear cells were suspended in 5ml conventional culture medium. Then cells derived from adult human bone marrow were seeded with a concentration of 1×10⁶cells/ml in DMEM in 25cm² culture flask. Cultures are maintained at 37°C in a humidified atmosphere containing 5%CO₂. The medium was changed first time after 72 hours, and once every 3 days thereafter. When the cultures reached nearly 80% of confluence, cells were trypsinized by 0. 25% trypsin, collected, resuspended, and passaged with a concentration of (6-8)×10³cells/cm² in conventional culture medium in a 25cm² culture flask. The media were changed every 3 days. The passage 3 MSCs were seeded with a concen-...