Cellular delivery for vascularization of engineered tissues: Reduction of contraction by mural cells

Early perfusion is essential for survival and function of engineered tissues. A promising solution to this problem is the development of stable microvessels within an engineered construct. Transplantation of human endothelial cells within protein gels has been shown to form functional vascular networks both in vitro and after implantation into immunodeficient mice. Co-transplantation of human pericytes, a supporting cell in microvessels, can significantly improve the maturation and stability of vessels formed compared to endothelial cells alone. We hypothesize that the optimization of a system for simultaneous delivery of endothelial cells and pericytes will improve vascularization and vascular stability in engineered tissues. Pericytes are contractile, which can interfere with the formation of vascular structures in protein gels. Here we evaluate strategies to prevent gel contraction.