Graphene coatings for enhanced hemo-compatibility of nitinol stents

In this study, we used graphene, a one-atom thick sheet of carbon atoms, to modify the surfaces of existing implant materials to enhance both bio- and hemo-compatibility. This novel effort meets all functional criteria for a biomedical implant coating as it is chemically inert, atomically smooth and highly durable, with the potential for greatly enhancing the effectiveness of such implants. Specifically, graphene coatings on nitinol, a widely used implant and stent material, showed that graphene coated nitinol (Gr-NiTi) supports excellent smooth muscle and endothelial cell growth leading to better cell proliferation. The authors further determined that the serum albumin adsorption on Gr-NiTi is greater than that of fibrinogen, which is an important and well understood criterion for promoting a lower thrombosis rate. These hemo- and biocompatible properties, along with high strength, chemical inertness and durability provide graphene with an edge over most antithrombogenic coatings for biomedical implants and devices.