Fig. 4.

Perivascular localization of hMSCs. A seeded scaffold containing HUVECs and MesenPro-treated MSCs was explanted after 4 weeks and embedded in paraffin. Serial sections cut from a region containing several transverse vessels (two of which are marked by arrowheads) were immunohistologically stained to identify human-derived structures: a human-specific antibody for PE-CAM (CD31) stained graft-derived endothelium, vascular-associated MSCs stained positive for the mural markers smooth muscle actin (ACTA2) and calponin (CNN1). Numerous erythrocytes within lumens indicate that the vasculature has anastomosed and is functional. Positive signals are brown with hematoxylin counterstaining. (Scale bar: 25 μm.).