Fig. 9

Bionic composite hydrogel Gel-OCS/MBGN regulates bone defect healing through loading EVs to modulate the miR-19b-3p/WWP1 axis. Note A Observing the healing of femurs in each group of rats by naked eye; B, C Observing the new bone formation at the site of femoral defect in each group of rats by X-ray and Micro-CT; D, E BV/TV and BMC analysis in (C) (* indicates P < 0.05 compared with PBS group, # indicates P < 0.05 compared with Gel-OCS/MBGN@EVs-inhibitor NC group); F Pathological changes in new bone formation at the site of femoral defect in each group of rats detected by H&E staining, Scale bar: 200 μm; G Collagen fiber formation in new bone formation at the site of femoral defect in each group of rats detected by Masson staining, Scale bar: 100 μm; H, I Expression of OPN, a marker of osteogenic differentiation, detected by immunohistochemical staining in each group of rats at the site of femoral defect (cytoplasm), Scale bar: 50 μm, red arrows indicate OPN-positive cells; J Expression levels of miR-19b-3p and WWP1 at the site of femoral defect in each group of rats detected by RT-qPCR (N = 6, * indicates P < 0.05 compared with PBS group, # indicates P < 0.05 compared with Gel-OCS/MBGN@EVs-inhibitor NC group). K Western blot was used to detect the protein expression levels of WWP1 in the femoral defect of each group (N = 6, * indicates P < 0.05 compared with the PBS group, # indicates P < 0.05 compared with the Gel-OCS/MBGN@EVs-inhibitor NC group)