Smooth muscle cell ingrowth of a surface-modified ePTFE vascular graft

A variety of attempts have been made to improve small diameter expanded polytetrafluoroethylene (ePTFE) vascular grafts through cellular and tissue engineering. Some of these techniques have made their way into clinical trials. Coating of endothelial cells via surface modifications has increased graft patency in some hands but lack of firm adhesion of the seeded cells on the graft surface can lead to graft failures. We increased cell-graft and graft-tissue interactions by inducing smooth muscle cell growth into the pores of the graft wall through chemical modification of superficial surfaces, including those of the transmural pores. In contrast to non-modified surfaces seeded cells adhered on and proliferated into the modified pores and internodal surfaces. Cellular growth into these critical pores spaces seemed to arise from surface modification including defluorination and oxygenation incorporation leading to changes in chemical composition, surface tension, cell-surface interaction and modified surface fibril aggregation.