Fluorine-incorporated amorphous carbon coating inhibits adhesion of blood cells to biomaterials

When the surfaces of biomaterials come into contact with human blood, the contact can induce adhesion and activation of platelets and leukocytes following protein adhesion, and these complex reactions cause responses in the body including biomaterial-associated thrombosis and inflammation. Fluorine-incorporated amorphous carbon (a-C:H:F) is widely known as an antithrombogenic thin film and is regarded as a promising coating that can solve the problem of blood-contacting medical devices. However, the anti-inflammatory properties of a-C:H:F have not yet been elucidated. Polymorphonuclear neutrophil leukocytes (neutrophils) play important roles in thrombosis and inflammation, and platelets that adhere to and become activated on biomaterial, which are also key factors of thrombus formation, promote adhesion of neutrophils in an inflammatory process. In this study, to evaluate the antithrombogenic and anti-inflammatory properties of a-C:H:F coating, we analyzed the platelets that had adhered to and become activated on, as well as neutrophils that had adhered to, a-C:H:F-coated SUS316L, which is a conventional material used for medical devices. The a-C:H:F-coated SUS316L suppressed platelet adhesion and activation and neutrophil adhesion to a greater extent than uncoated SUS316L. These results showed that a-C:H:F coating is a suitable and biocompatible coating for implanted devices because it controls the initial thrombotic and inflammatory reactions of biomaterials.