Superhemophobic titania nanotube array surfaces for blood contacting medical devices

Abstract

Hemocompatibility of blood-contacting medical devices is necessary to prevent device failure. As soon as a material encounters blood, proteins and platelets will adsorb and attach to its surface. This leads to thrombosis and clot formation on the surfaces, restricting blood flow and in some cases leading to inflammation and device failure. To avoid these complications, patients receiving blood-contact devices are prescribed blood thinning medications, which must be taken for the rest of the patient's life. Some devices can be pre-clotted to improve hemocompatibility, but the benefits will not last the device's entire life. Enhancing hemocompatibility has been a focus of recent research. Proposed methods have included diamond-like carbon surfaces, heparin-based surface coatings, modified polymer surfaces, and titania nanotube arrays. These methods have all shown some enhancement of hemocompatibility initially, but no approach has proven durable over long periods of time. Superhemophobic surfaces are a new approach to improving hemocompatibility, but the interactions of blood components with these surfaces have not been studied in depth. In this study, we have developed superhemophobic surfaces by modifying the surface topography and surface chemistry of titanium. The surface topography was modified by creating titania nanotube arrays through a well-documented anodization technique. Superhemophobicity was induced by modifying the titania nanotube arrays with two different silanes using chemical vapor deposition. The investigations of blood interactions with superhemophobic surfaces showed reduced protein adsorption and platelet adhesion/activation, indicating this a potential approach for enhancing material hemocompatibility.