Development and Biomechanical Characterization of a Novel Bilayer Vascular Graft

Abstract

Vascular grafts are currently used to treat cardiovascular diseases such as arthrosclerosis by bypass surgery and as vascular access in hemodialysis [1]. There are a number of types of grafts including autologous vessels (such saphenous vein), synthetic grafts (such as expanded polytetrafluoroethylene) and tissue engineered blood vessels. Currently synthetic grafts are most commonly used as blood vessel replacements and there are a number of problems associated with them. One main impediment is that these grafts are not suitable for small-diameter (less than 6mm) vessel replacement [1, 2], due to high occlusion rates. The major concern over the other alternatives such as autologous vessels and tissue engineered products is their availability. Thus, new approaches to constructing biomimetic small-diameter blood vessel equivalents, that are immediately available, may address the unmet demand in this area. Therefore, we have designed a novel bilayer vascular construct which is made up of a nanofibrous intimal-equivalent as thromboresistant vessel lumen and a mimetic extracellular matrix (ECM) as medial-equivalent for smooth muscle cells (SMC) from native artery to invade and remodel the ECM.