Unloaded or O2-loaded 20% μtank scaffolds and ASCs were implanted into 4 mm murine calvarial defects for 8 weeks. (A, B) μCT of calvarial defects with scaffolds pseudocolored magenta and compared to empty defects in the contralateral side; scale bar = 4 mm. (C) Quantification of bone volume normalized to empty defect (n = 5), (D) Quantification of bone cross-sectional area compared to empty defect (n = 5), (E,F) H&E (inset boxes show where OPN immunostaining in I and J were taken from) and (G, H) Masson’s trichrome staining; Scale bar in E-H = 500 μm, (I, J) Immunofluorescence images of osteopontin staining; Scale bar = 50 μm, (K) Quantification of OPN immunostained area (n = 12), (L) Quantification of OPN signal intensity (n = 12). (*,*** represent p < 0.05, 0.001).