Surface Engineering of Poly(ethylene terephthalate) for Durable Hemocompatibility via a Surface Interpenetrating Network Technique

Heparin was covalently bonded on chemically inert PET substrate using a surface modification technique–surface interpenetrating network with the purpose of fabricating long‐lasting biocompatible materials as vascular grafts. FTIR and XPS spectra confirmed the successful heparinization of PET (PET‐Hep). The density of surface‐immobilized heparin as quantified by a colorimetric method could reach 2.4 μg cm−2 (in the reported optimal range: 1.5–3.0 μg cm−2). The hemocompatibility of the heparin‐immobilized PET was improved as evidenced by a platelet adhesion test: significantly less platelet adhesion on PET‐Hep (11.60%) than on untreated PET (48.91%). An MTT assay indicated PET‐Hep was nontoxic to human dermal fibroblast cells. After an initial 5.24% loss of heparin from PET‐Hep in the first 14 h immersion in PBS buffer solution, no further leaching of heparin was found.