Surface-engineering of Poly(ethylene terephthalate) for improved haemocompatibility

Abstract

Cardiovascular diseases (CVD) remain the number one cause of mortality globally. Compared with autologous vessels, synthetic vascular grafts such as poly (ethylene terephthalate) (PET) vascular grafts are still widely used to replace or bypass diseased arteries. However, PET is susceptible to thrombosis when in contact with blood. In this study, “bioactive”/“bioinert” agents – heparin and poly(ethylene glycol) (PEG) were immobilized covalently on chemically inert PET substrate using a special surface modification technique – surface interpenetrating network (IPN) successfully. The improved haemocompatibility of heparin modified PET surface was proved by a platelet adhesion assay. The PEG modified PET substrate also demonstrated decreased platelet adhesion. Further research has been conducted to immobilize aliphatic chains ended with sulfate and carboxylate groups (existing in heparin) on a model substrate. In vitro thrombus formation test indicated an interesting anticoagulating action between those anionic groups with an optimal ratio in the range of (3:1) and (4.5:1).