Fig. 7

Histological analysis on ACLR postoperative. A Representative image of the tendon-bone interface by hematoxylin and eosin staining at 4 and 8 weeks postoperatively among the control group, the BMSC-Exos group and the BMSC-Exos mimic group, with quantification of the relative width of the interface. Scale bar: 200 μm. B The interface is outlined by the black line. C–E Safranin-O/Fast Green staining at the tendon-bone interface and quantification of fibrocartilage in the interface region after ACLR at 4 and 8 weeks postoperatively among the control group, the BMSC-Exos group and the BMSC-Exos mimic group. Scale bar: 100 μm. F, H Immunohistochemical staining of COL2α1 at the tendon-bone interface and quantification after ACLR at 4 and 8 weeks postoperatively among the control group, the BMSC-Exos group and the BMSC-Exos mimic group. Scale bar: 100 μm. I, J Immunofluorescence staining of CD163 at the tendon-bone interface and quantification after ACLR at 2 weeks postoperatively among the control group, the BMSC-Exos group and the BMSC-Exos mimic group. Scale bar: 50 μm. B, bone; T, tendon graft. Data are presented as mean ± SD. Statistical analysis was performed with one-way ANOVA followed by Tukey’s multiple comparisons test. n = 6. ^*P < 0.05, ^**P < 0.01.