FIGURE 7.

In vivo evaluation of PPD‐sEVs for OA improvement in the ACLT mouse model. (A) Schematic illustration of ACLT surgery, sEVs intra‐articular injection, and cartilage harvest timeline; (B) Representative images of H&E and Safranin O‐Fast Green (Safranin O) staining. Black triangles indicate cartilage loss and destruction, scale bar: 200 μm; (C) Statistic data of OARSI scores in each group (n = 5); (D) Representative images of immunohistochemistry analysis for cartilage matrix anabolism biomarkers (Aggrecan, Collagen Ⅱ) and catabolism biomarkers (ADAMTS5, MMP13) in each group, scale bar: 100 μm; (E, F) Quantitative analysis of immunohistochemical staining of cartilage matrix anabolism biomarkers (Aggrecan, Collagen Ⅱ) (n = 5); (G, H) Quantitative analysis of immunohistochemical staining of cartilage matrix catabolism biomarkers (ADAMTS5, MMP13) (n = 5). The fold change of each marker in each group was normalized against the Sham group (vs. Sham group); (I) Representative images of TUNEL staining analysis to detect chondrocyte apoptosis (Red) in articular cartilage in different groups, scale bar, 100 μm; (J) Quantitative analysis of apoptotic chondrocytes in each group (n = 5), scale bar, 100 μm. *P < 0.05, **P < 0.01