Chondrogenic evaluation of expanded cells. After expansion on Plastic, BECM, or UECM, hBMSCs or hUSCs were cultured in a pellet system supplemented with a serum-free chondrogenic medium for 14 days. (a–d) Alcian blue staining (AB) and (e–h) immunohistochemical staining (IHC) were used to detect sulfated GAGs and type II collagen, respectively. Scale bar = 800 μm. Biochemical analysis was used to measure DNA and GAG amount, which can be used to calculate (i) DNA ratio (cell viability) and (j) ratio of GAG to DNA (chondrogenic index). TaqMan® real-time PCR was used to evaluate (k) ACAN and (l) COL2A1 mRNAs. * p < 0.05. Data are shown as average ± SD for n = 4.