In vitro comparative biocompatibility testing of Carbofilm coated and uncoated polyetherimide for cardiovascular application

When blood contacts the surface of a material, several processes take place including the activation of coagulation and immune systems. The aim of this work is to study in vitro the biological reactions seen from the point of view of hemocompatibility and cytocompatibility of a new polymer suggested as an artificial surface for cardiovascular applications: Carbofilm® coated polyetherimide (C®PEI) in comparison to polyetherimide (PEI), the uncoated form. PEI and C®PEI showed no signs of acute cytotoxicity although following long term incubation with PEI cytotoxicity was somewhat increased; both materials supported good endothelial cell adhesion with a higher level of cell proliferation on the coated form. No significant difference was detected in the activation of the inflammatory response and in thrombogenicity tested by assay of prostaglandin E2 (PGE2) and tromboxane B2 (TXB2) respectively, following incubation of the biomaterials with platelet-rich plasma (PRP). Complement activation assessed by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE)/Western Blot analysis of both contacting plasma and protein which adsorbed on the surface of the polymers showed both materials to be activators of complement. In conclusion, Carbofilm® coating, showing lower cytotoxic activity and higher endothelial cell growth in comparison with uncoated material, seems to increase PEI compatibility.