Osteogenic differentiation of human adipose-derived stem cells : comparison of two different inductive media

Human mesenchymal stem cells (MSCs) have the potential to differentiate into cells of connective tissue lineages, including bone, cartilage, fat, muscle and also neurons. In our study we have examined the phenotypic profile of human adipose tissue-derived stem cells (hASCs) and compared different osteogenic-inductive media to assess hASC differentiation. Cells were enzymatically isolated from adipose tissues derived by liposuction from several adult human donors, purified and then expanded in culture. We obtained an abundant yield of hASCs with a constant proliferative trend, a doubling time of about 68 h and a mild variable clonogenic capacity. At passage 4, hASCs expressed MSC-related cell surface antigens (CD13, CD105, CD54, CD90, CD44), and subsequently hASCs were induced to differentiate into the osteogenic lineage for at least 3 weeks of culture in two distinct media, OM1 and OM2, differing in dexamethasone and ascorbic acid concentrations. Osteogenic differentiation of OM1- and OM2-cultured cells was assessed by evaluating cell morphology, osteopontin expression, alkaline phosphatase activity and calcium deposition. OM2 medium showed a higher osteogenic potential than OM1, as assessed by increased levels of calcium deposition, alkaline phospatase activity and osteopontin expression in comparison with OM1-differentiated cells. We conclude that hASCs efficiently differentiate into osteogenic lineage, particularly when cultured in inductive medium supplemented with 10 nM dexamethasone and 150 microM ascorbic acid.