TRANSPLANTATION OF HUMAN ENDOTHELIAL-CELL MONOLAYER ON ARTIFICIAL VASCULAR PROSTHESIS - THE EFFECT OF GROWTH-SUPPORT SURFACE-CHEMISTRY, CELL SEEDING DENSITY, ECM PROTEIN COATING, AND GROWTH-FACTORS

The failure rates of synthetic vascular grafts, when placed in low blo od flow environments in humans, are not acceptable. Thus, endothelial cell (EC) seeding technology of vascular grafts was developed to prepa re prostheses lined with a human monolayer expressing optimal thrombor esistant properties. In a clinical setting, endothelialization of a gr aft can be achieved using higher cell seeding densities, or by creatin g a surface on which EC can adhere and grow to confluence. But, human endothelial cells show little or no proliferation on the currently ava ilable graft materials. In this study, surface modification of PTFE an d ePTFE by ammonia plasma treatment was carried out to enhance its int eractions with ECM protein, EC growth factors, and with EC harvested f rom human umbilical vein (HUVEC), and from human saphenous veins (HSVE C). Our data shows that various vascular graft materials generated fro m ammonia plasma treated PTFE and ePTFE exhibited statistically signif icant improvements in HUVEC and HSVEC growth when compared to their re spective controls (p values < 0.001). Growth of HSVEC on ammonia plasm a treated ePTFE without ECM protein coating was also found to be stati stically significant in comparison to that on fibronectin coated ePTFE (p < 0.001). The final HSVEC cell densities found on various ePTFE su rfaces prepared from ammonia plasma treated ePTFE, suggests that trans plantation of HSVEC monolayers on vascular prostheses can be establish ed within clinically relevant times. Ammonia plasma treatment process provides an unique opportunity to surface modify prosthetic materials of various construct to transplant mammalian cells including those tha t have undergone ex vivo gene transfer, and to deliver angiogenic mole cules to a target area for tissue development.