Figure 4. Intra-articular injection of psoralen significantly promoted OA rabbit model cartilage regeneration in vivo. (A) Macroscopic observation of femoral condylar cartilage. (B) HE staining, (C) Masson staining, (D) Safranin O/Fast Green staining, (E) Gross morphological score, (F) Histological score. The lower score, the smaller the cartilage damage and the better the repair effect. ** represents P < 0.01, *** represents P < 0.001.