Fig. 5

Assessment of osteogenesis in the bone tissue. a Western blot analysis showed that the Smad1, RUNX2, BMP-2, OPN and OGN protein levels increased in the bone tissue of the fracture sites stimulated with BMMSC-Exos. b The grey value ratios were quantified using ImageJ software (NIH, USA). The experiments were performed on three separate occasions. c The immunohistochemical analysis of BMMSC-Exos promoted osteogenesis in vivo. Immunohistochemical analysis of BMP-2 (C1), Smad1 (C2), RUNX2 (C3), OPN (C4), OGN (C5) and OCN (C6) was used to detect osteogenesis in the femur specimens. The brown colour represents positive staining of BMP-2, Smad1, RUNX2, OPN, OGN and OCN. The integrated optical density of positive staining was measured (C1′–C6′). Abbreviations: CM, conditioned medium; CM-Exo, exosome-depleted conditioned medium; Exo, exosomes. **P < 0.01 vs the control group; ^##P < 0.01 vs the CM-Exo group