Engineered Vascular Graft Using Nanoscale Decellularized Arteries Modified with Controlled-Release Heparin and Vascular Endothelial Growth Factor

We designed and developed a readily-available vascular graft for in situ tissue engineering using nanoscale decellularized arterial scaffolds modified with heparin hyaluronic acid (HA) hydrogel and sustained release vascular endothelial growth factor (VEGF) gelatin microspheres. Heparin HA hydrogel offered anti-coagulation properties and inhibited platelet aggregation (in vitro and in vivo), while controlled-release VEGF facilitated bone marrow stromal cell proliferation for nearly one month in vitro. Once implanted, the engineered vascular grafts were patent, antithrombotic, assisted the recruitment of endothelial cells in vivo, enhanced endothelium formation and maintained mechanical stability, whereas all the control grafts occluded. Our histological, immunohistochemical and electron microscopic analyses of the engineered vascular grafts demonstrated the existence of endothelial cells, smooth muscle cells and the presence of extracellular components such as collagen and elastin for two months post-implantation. This work demonstrates the feasibility of vascular graft with an anticoagulation activity and can recruit endothelial cells properties for in situ blood vessel regeneration.