An Overview of DLC Coatings for Biological Applications

This paper gives an overview on diamond-like carbon (DLC) coatings in biomedical research and applications. DLC is a class of materials with shows an excellent biocompatibility as well as very good tribological properties. By the incorporation of additional elements into the DLC all of these properties can be changed within a certain range. The amount of different proteins adsorbed on the surface can be influenced by the concentration of additional elements in the DLC film. These adsorbed proteins will then subsequently influence cell attachment, cell proliferation and cell differentiation. Certain toxic elements such as Cu, Ag, V, embedded in the DLC will, when exposed to a biological media, be released and cause toxic reactions. This allows the preparation of surfaces with a tunable antibacterial effect. Concerning the wear of UHMWPE cups operated against DLC coated hip joint balls, depending on the experimental setup, different results are found in the literature. Especially, the proteins adsorbed on the joint surfaces strongly influenced the wear results obtained. DLC coatings have an excellent haemocompatibility, which is expressed in a decreased thrombus formation. DLC coated cardiovascular implants such as artificial heart valves, blood pumps and stents are already commercially available.