Figure 1. Coimplantation of human Mesenchymal Progenitor Cells and Endothelial Progenitor Cells induces in vivo vascularization of a tissue construct.

During embryogenesis, angioblasts differentiate into Endothelial Cells and organize to form the primordial capillary-like structures. Mesenchymal Stem Cells differentiate into pericytes assuming positions surrounding the endothelial cells in the newly formed vessels. Pericytes regulate maturation and stabilization of the vascular network. Melero-Martin and colleagues reproduced vasculogenesis in a tissue construct using Matrigel as the scaffold. Cord blood-derived Endothelial Progenitor Cells or adult blood Endothelial Progenitor Cells where co-implanted with either bone marrow-derived or cord blood derived Mesenchymal Progenitor Cells to produce a stable and mature vascular network when implanted in vivo. The vascular structures where composed of human Endothelial Progenitor Cells surrounded by α-smooth muscle actin positive mesenchymal cells anastomosed with host vessels.