Optimization of peptide modified gold coated polyurethanes as potential substrates for endothelial cell growth

Over 350,000 vascular graft replacements are performed in the United States each year. While the use of artificial materials has proved adequate for large diameter implants problems with long-term patency of small diameter grafts have yet to be overcome. Graft failure is often due to activation of the intrinsic mechanism for blood clotting due to blood contact with the artificial surface. This can lead to thrombus formation, emboli and occlusion of the blood vessel. Attaching the naturally occuring endothelial cell layer to the lumen of the artificial vessel could provide the antithrombotic mechanism normally present in vivo. To provide this protection, the lumen of the artificial blood vessel needs to be made amenable to endothelial cell growth. To this end, it is proposed that the use of gold coated polyurethanes for the chemisorption of cell adhesion peptides, via the thiol moiety of cysteine, could be used to promote endothelial cell growth. In this study, cysteine and three syntehtic peptides, were chemisorbed to gold coated polyurethane surfaces. The modified surfaces were characterized and the effect of amino acid concentration and chemisorption time on the surfaces was analyzed. Quantification of the chemisorbed cysteine via an enzyme linked assay was also attempted.NRC publication: Ye