Functionally-graded 3D Tubular Scaffolds for Vascular Tissue RegenerationTo date, there is no small-diameter prosthetic arterial graft (<6 mm) clinically accepted for use in the peripheral circulation and coronary vessels, which affects over 500,000 patients each year. Purely synthetic grafts such as Dacron and Polytetrafluoroethylene (PTFE) have been effective for some vascular applications, but are limited to the high-flow/low-resistance conditions of large diameter vessels (>6 mm) due to unsatisfactory long term patency because of thrombosis and intimal hyperplasia. Many alternative vascular grafts have been engineered using synthetic polymer and animal-derived matrices to overcome these complications. Prosthetic grafts can be seeded with endothelial cells (ECs); however, adhesion/retention of endothelial cells to naked scaffolds is poor. Therefore, there is an unmet need for bioengineered vascular device, especially small diameter grafts for coronary bypass.
We have recently engineered a functionally-graded vascular graft by integrating bioresorbable synthetic polymers with vascular proteins. This 3D tubular construct of nanomatrix mimics the layered-matrix structure of native arteries by matching mechanical and functional properties for vascular grafts. Moreover, incorporation of vascular proteins such as collagen and elastin that allows viable tissue constructs by cultivating single or multiple cell types. ECM milieu could also be controlled by enrichment with specific growth factors (e.g.VEGF) for angiogenesis. We focus to combine our functionally-layered graft strategy with the incorporation of physiologically-relevant native ECM biomatrices system for fabricating an advanced 3D vascular construct demonstrating enhanced lumen endothelialization and robust biomechanics.