Development of a Tri-Layered Vascular Construct and In Vitro Evaluation of Endothelization.

Abstract

Advances in the development of vascular substitutes for small-sized arteries are ongoing because the present grafts do not entirely meet the requirements of native equivalents and are suboptimal in clinical performance. This study aims to develop a tri-layered vascular construct mimicking natural tissue using polyester blends and to investigate its endothelization through in vitro studies as a potential small-caliber vascular graft. The innermost layer is obtained by dip coating as a tubular porous film with a lumen diameter of 3mm and a pore size of ≤8µm. Circumferentially aligned electrospun fiber (diameter 100-800nm) with a deviation angle of 15° are deposited over the porous film forming the intermediate layer. The random electrospun fibers (diameter 100-1100nm) deviating at different angles are wrapped as the outermost layer. The mechanical properties of the tri-layered vascular construct are determined to be 44.80±14.80MPa for Young's modulus and 4.25±0.75MPa for ultimate tensile strength. MTS and cell behavior studies show that the isolated human umbilical cord vein endothelial cells proliferate and line the lumen of the vascular substitute. The vascular construct developed, with its biomimetic architecture, mechanical features, size, and endothelization, can be tested with in vivo studies.