Enhanced Long-term Antithrombogenicity Instigated by Covalently-Attached Surface Modifier on Biomedical Polymers

Abstract

During a variety of medical procedures such as renal dialysis, bypass surgery, and lung transplantation patient blood is exposed to the surface of a number of polymeric materials such as polycarbonate (PC), poly (vinyl chloride) (PVC) and polysulfone (PS) for a period up to several days. Such exposure may result in undesirable protein-material interactions that can potentially trigger deleterious biological processes including thrombosis, which may be responsible for other complications such as cognitive disability. In order to address this issue, we have further examined the behavior of an ultrathin antifouling and antithrombogenic coating based on monoethylene glycol silane surface chemistry. Samples of polymeric substrates were exposed to blood flow at a shear rate of ~20 s-1 for time periods of 3 and 6 hours, as well as 3 days. No additional anticoagulant chemistry was applied in the experiments. For all time periods, platelet adhesion, aggregation, and thrombus formation on the coated surfaces was inhibited compared to bare substrates (coated PC performing the best, followed by PVC-, and then PS-coated), strongly supporting the results of previous research conducted over far shorter blood contact times.