Fig. 5. Effects of short-term hypoxic treatment on SVFC osteogenic differentiation and vascularization within 3D bioprinted constructs in OGM/EGM. (A) Timeline and treatment for 3D bioprinted SVFC laden constructs. Hypoxia group represented the 7 day hypoxic conditioning and 14 day normoxic conditioning, while the normoxia group represented 21 day culture in normal oxygen tension; (B) short-term hypoxia did not significantly change ALP expression and activity (scale bar = 1 mm); (C) IHC staining of αSMA and CD31 after in total 21 day culture in both groups (scale bar = 50 μm); (D) qPCR analysis of vascularization markers (i.e. VEGFA, VE-cadherin and HIF1A) and osteogenic differentiation markers (i.e. ALP, Runx2 and OCN) in 3D bioprinted constructs after 21 day culture in normoxia and hypoxia groups. Relative gene expression is presented as normalized to 18S and expressed relative to cells in normoxia for 21 days (n = 3; *p < 0.05, **p < 0.01).