(A) Articular cartilage repair scores at 2 weeks postoperation (n=10). (B–G) Representative histology of full cartilage repair at 2 weeks postoperation. Specimens from young mice (B, C), juvenile mice (D, E), and adult mice (F, G) are stained with hematoxylin and eosin and Safranin-O stains. Scale bar, 100 μm. *p<0.0001.