Human adipose-derived stem cells isolated from young and elderly women: their differentiation potential and scaffold interaction during in vitro osteoblastic differentiation.

BACKGROUND AIMS: Several authors have demonstrated that adipose tissue contains multipotent cells capable of differentiation into several lineages, including bone, cartilage and fat. METHODS: This study compared human adipose-derived stem cells (hASC) isolated from 26 female donors, under 35 and over 45 years old, showing differences in their cell numbers and proliferation, and evaluated their in vitro adipocytic and osteoblastic differentiation potential. RESULTS: The cellular yield of hASC from older donors was significantly greater than that from younger donors, whereas their clonogenic potential appeared slightly reduced. There were no significant discrepancies between hASC isolated from young and elderly women regarding their in vitro adipocytic differentiation, whereas the osteoblastic potential was significantly reduced by aging. We also assessed the influence of hydroxyapatite (HAP) and silicon carbide (SiC-PECVD) on hASC. Even when cultured on scaffolds, hASC from younger donors had better differentiation into osteoblast-like cells than hASC from older donors; their differentiation ability was up-regulated by the presence of HAP, whereas SiC-PECVD produced no significant effect on hASC osteoblastic differentiation. CONCLUSIONS: The large numbers of hASC resident in adipose tissue and their differentiation features suggest that they could be used for a successful bone regeneration process in vivo. We have shown that age does not seem to affect cell viability and in vitro adipocytic differentiation significantly, whereas it does affects osteoblastic differentiation, in the absence and presence of two-dimensional and three-dimensional scaffolds.

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.