Human and mouse specific perivascular gene expression before and after implantation. (A) The expression of human specific perivascular biomarkers α-smooth muscle actin (α-SMA) and SM22α were both up-regulated in co-culture before implantation. (B) There were no differences in the expression of the angiogenic factors VEGFa, ANG-1 and ANG-2 using mouse specific assays at either time point in vivo. Expression of mouse α-SMA was up-regulated one week post-implantation in the EC-group, the opposite regulation as was observed with the human specific α-SMA assay. No differences were found for mouse α-SMA three weeks post-implantation. ** = P <0.01. ANG-1, angiopoietin-1; ANG-2, angiopoietin-2; EC, endothelial cell; VEGFa, vascular endothelial growth factor-a.