Figure 7.

Biochemical analyses of mesenchymal stem cell aggregates following chondrogenic induction. Primary mesenchymal stem cells were infected with Ad.GFP (controls), Ad.IHH alone (IHH), or in combination with TGF-β1 (IHH + TGF-β1) or BMP-2 (IHH + BMP-2), placed into aggregate cultures and assayed biochemically over a 3-week time course. (a) Cell proliferation was evaluated using the ATP assay, and (b) glycosaminoglycan (GAG) content and (c) relative alkaline phosphatase (ALP) activity normalised to DNA are shown for quantification of cartilage matrix production and hypertrophy, respectively. Bars represent mean ± standard deviation from three pellets per group and patient, assessed on five marrow preparations from different patients. *Significant difference (P < 0.05) compared with marker gene-transduced controls. Ad., adenoviral vector; BMP, bone morphogenetic protein; IHH, Indian hedgehog; TGF-β, transforming growth factor beta.