Size and shape of aggregates and biochemical analyses. Gross images of representative aggregates of each studied group are presented. (A) Aggregates transduced with single adenoviral vectors correspond to positive controls (a) and (b), Ad.SOX9 (c), Ad.FGF-2 (d), Ad.TGF-β1 (e), and AD.IGF-1 (f). (B) Aggregates transduced with combined adenoviral vectors correspond to positive controls (g) and (h), Ad.IGF-1/Ad.TGF-β1 (i), Ad.IGF-1/Ad.FGF-2 (j), Ad.SOX9/Ad.IGF-1/Ad.TGF-β1 (k) and, Ad.SOX9/Ad.IGF-1/Ad.FGF-2 (l). (C) Biochemical analyses of in vitro aggregates for total content of DNA, glycosaminoglycans (GAGs) and collagen. Aggregates were papain-digested and analyzed for total content of DNA, sulfated GAGs, and synthesized collagen. The content of GAGs and collagen were normalized by the DNA content of each sample. Data are presented as a mean ± standard deviation from three aggregates per group (n = 3). *P <0.05.