Fig. 4

Therapeutic effect of BMSCs with different ER stress levels on cartilage defects. a Macroscopic appearance in cartilage defect healing in the four groups at 4, 12, and 26 weeks after surgery. b ICRS macroscopic scores for all samples from the four groups at different times after surgery (Fig. 4 a). c Biomechanical testing was performed at 12 weeks and 26 weeks after surgery. d Safranin O-fast green staining of repaired cartilage in vivo at each time point, respectively. Scale bar: 200 μm. e Histological scores for the samples from the four groups according to the ICRS Scale (Fig. 4 d). The values were means ± S.D.; * indicate P < 0.05, ** indicate P < 0.01, *** indicate P < 0.001