Platelet inhibition and endothelial cell adhesion on elastin-like polypeptide surface modified materials

Platelet adhesion and activation are important early markers of biomaterial blood compatibility, while surfaces that promote enhanced endothelial cell adhesion and eNOS expression are strategic targets for long term vascular graft applications. Materials surface modified with fluorinated surface modifiers, containing peptides inspired from elastin cross-linking domains, have been used for the cross-linking of elastin-like polypeptide 4 (ELP4) macromolecules onto polyurethane surfaces. In the present study, ELP4 modified polyurethanes were evaluated in vitro to assess platelet adhesion, microparticle formation and bulk platelet activation following blood-material interactions. Reduced platelet adhesion and bulk platelet activation were observed following contact between reconstituted human blood and the ELP4 materials, relative to the uncoated base polyurethane controls. ELP4 modified materials also promoted endothelial cell adhesion and retention over a period of one week and showed that the endothelial cells exhibited an organized actin cytoskeleton and enhanced endothelial nitric oxide synthase (eNOS) expression relative to the control surfaces. These results indicate that polyurethane elastomers modified with ELP4 covalently bound to fluorinated surface modifiers provide a promising approach for endowing synthetic elastomers with both reduced blood platelet activation properties and enhanced endothelial cell adhesion for potential use in vascular graft applications.