Expression of vascular endothelial growth factor-a (VEGFa) from human cells. Baseline gene (A) and protein (B) expression of VEGFa was significantly higher for MSCs compared with ECs grown in two-dimensional culture in vitro. (C) The relative gene expression of VEGFa from co-cultured constructs was also higher one week after dynamic three-dimensional culture in vitro and one week after implantation in vivo. * = P <0.05, ** = P <0.01, *** = P <0.001. ECs, endothelial cells; MSCs, mesenchymal stem cells.