Fig. 7.

ETV2-DPSCs/MS accelerate recovery of rat critical-size bone defect by rapid activation of HIF-1 signaling (A) Representative images of the three-dimensional reconstruction of rat calvarial defects using micro-CT at four weeks post-surgery. The orange circle outlines the 5 mm-diameter initial defect range. (B) Quantitative analyses of BMD, BV/TV, BS/TV, and Tb.Th (C) H&E staining of the defect area. The black arrow indicates neovasculars. Scale bar: 200 μm (D) Representative images of immunofluorescence labeling RUNX2 in tissue sections of defect area at 3 d post-modeling. Red arrows indicate RUNX2⁺ cells. Scale bar: 200 μm (E) Representative images of immunofluorescence labeling CD31 in tissue sections of defect area at 3 d post-modeling. Red arrows indicate novel blood vessels. Scale bar: 200 μm (F) Representative images of immunofluorescence co-staining ETV2 (red) and HIF-1α (green) in tissue sections of defect area at 3 d post-modeling. Scale bar: 200 μm (G) Representative images of immunofluorescence co-staining OPN (green) and Collagen-1 (red) in tissue sections of defect area at four weeks post-modeling. Scale bar: 200 μm (H–L) Quantification of the proportion of RUNX2⁺ cells, neovascularization region, HIF-1α⁺ cells, OPN⁺ area, and COL-1⁺ area. (MS, microsphere; NB, novel bone; F, fibrous tissue; and NC, negative control. Data are presented as the mean of >3 independent experiments ±SD. *P < 0.05, **P < 0.01, and ***P < 0.001).