Bone marrow-derived mesenchymal stem cell (BMSC)-seeded scaffold diameter during chondrogenesis. BMSCs were isolated/expanded under normoxia or hypoxia, seeded within collagen or hyaluronic acid (HA) scaffolds, and subsequently differentiated under normoxia or hypoxia for 14 days in chondrogenic medium. Construct diameter was assessed by using high-quality digital photography and ImageJ software. Data represent the mean ± standard error of the mean of constructs containing (A) collagen scaffolds or (B) HA scaffolds seeded with BMSCs from three donors (five constructs per donor) on the basis of oxygen tension group. Data were pooled on the basis of oxygen tension during expansion or differentiation for (C) collagen scaffolds and (D) HA scaffold seeded with BMSCs. Statistical analysis is represented by the following: *significant P <0.05, **significant P <0.01, and ***significant P <0.001. NS, not significant; RM ANOVA, repeated measures analysis of variance.