Fig. 4. Middle- and long-term in vivo efficacy of focal osteochondral defect treatment in nude rats.

A Macroscopic images of surgically created focal defects (left images of each group) and 4, 8, 12, and 24 weeks after treatments (right images of each time point). The top row shows native and defect only group. The bottom row shows defect and cell sheet group. B Safranin-O staining of each condition. Representative images of samples at 4 weeks (n = 14), 8 weeks (n = 3), 12 weeks (n = 3), and 24 weeks (n = 3) are shown. Bars: Top and third rows: 500 µm, second and bottom rows: 100 µm.