Expression of adhesion molecules and cytokines <i>in vitro</i> by endothelial cells seeded on various polymer surfaces coated with titaniumcarboxonitride

Although endothelial cell (EC) seeding improves the patency of vascular prostheses, the detachment of adherent ECs after the restoration of circulation remains one of the major obstacles. Polymer surfaces for endothelialization can be optimized. In this study, polyethylene terephthalate (PET), polypropylene (PP), polytetrafluoroethylene (PTFE), polyurethane (PUR), and silicone were coated with a titaniumcarboxonitride (Ti(C,N,O)) layer by a plasma-assisted chemical vapor deposition process to verify the effect of titanium onto human saphenous vein ECs. Almost confluent EC monolayers were evaluated for 1) proliferation activity and 2) expression of adhesion molecules using cellular enzyme-linked immunosorbent assay and release of cytokines. The results showed that all titanium-coated polymers and uncoated PET have no toxic effect on human saphenous vein ECs excepting uncoated PTFE, PP, and silicone. Moreover, growing ECs showed an insignificant decrease in cytokine production and an unessential change in basal expression of adhesion molecules. Tumor necrosis factor-alpha-induced response depends on polymer surface: for example, intercellular adhesion molecule-1 expression decreased. E-selectin expression was unchanged for culturing ECs on coated PET, PP, and PTFE and reduced for polyurethane and silicone. Vascular cell adhesion molecule-1 expression was unchanged for coated PUR and silicone and reduced for PET, PP, and PTFE. In summary, titanium-coating layers promote adhesion of human ECs on polymer vascular grafts with no proinflammatory reaction of ECs.