Protein adsorption and platelet attachment and activation, on TiN, TiC, and DLC coatings on titanium for cardiovascular applications

Abstract

The hemocompatibility of a TiN/TiC/diamond-like carbon (DLC) multilayer structure, deposited on titanium substrates for use as coatings for a heart valve prosthesis, has been studied through the adsorption of blood proteins and the adhesion and attachment of blood platelets. All of the surfaces were characterized by stylus profilometry and water contact angles. The adsorption of albumin and fibrinogen to the surfaces was assessed using the Amido Black assay, whereas platelet attachment was studied by scanning electron microscopy and quantified using stereological techniques. The degree of platelet spreading on the surfaces was seen to correlate with differences in surface energy, indicated from contact angle measurements. The greatest spreading was seen on the more hydrophilic surfaces. When studying protein adsorption to the surfaces, no correlation could be determined between contact angle results and levels of adsorption, although the most hydrophilic surfaces did appear to promote greater amounts of fibrinogen adsorption. Thrombus formation was observed to some degree on all of the surfaces, with the exception of the DLC coating. This coating also promoted less spreading of platelets than the other surfaces. The good hemocompatibility of the DLC coating is attributed to its hydrophobicity and smooth surface, resulting in a higher ratio of albumin to fibrinogen than any of the other surfaces.

Electrochemical and antimicrobial properties of diamondlike carbon-metal composite films

“…For example, diamondlike carbon has been considered for use in a coronary artery stents, synthetic heart valves, left ventricular assist devices, and artificial hearts, because platelet activation and platelet adhesion occur less often on diamondlike carbon-coated surfaces than on conventional (titanium, titanium carbide, titanium nitride, or stainless steel) surfaces [31][32][33][34][35][36][37][38]. Another medical application for diamondlike carbon thin films is use on hip joint prostheses and knee joint prostheses.…”

Biofouling on protective coatings for implantable MEMS

“…It is also generally recognized that hydrophilic surfaces are more likely to resist protein adsorption, and that hydrophobic surfaces usually will adsorb a monolayer of tightly adsorbed proteins [6]. However, the nature of body contact determines the biological response and hydrophilic coatings seem not to be favorable for blood interfacing applications [7], [8], [9]. In the presented work, coatings generally accepted as biocompatible materials i.e.…”

Influence of Surface Texture on Friction Properties of Mechanical Seals for Blood -Design Concept of Sealing Surface of Mechanical Seal for Ventricular Assist Device-

“…Therefore, it is believed that the creation of small and dispersed concaves that can suppress protein adsorption is required to satisfy the requirements for mechanical seals in VADs. We propose Diamond-Like Carbon (DLC), which suppresses adsorption [19][20][21], should be coated on a textured seal ring to avoid periodic frictional peaks.…”