Bio-compatibility of the surface layer of pyrolytic graphite

Carbon materials are generally well tolerated by animal cells, so biomaterials of this type have come into routine use for constructing medical implants. The formation of surface layer makes them attractive for coating implants, e.g. in orthopaedic and dental surgery. The system biocompatibility is controlled mainly by its surface properties. The chemical state of the surface is given mainly by the material and by the method of surface preparation. On the other hand, biocompatibility can be improved by a suitable change of the surface morphology, e.g. by influencing the surface roughness. We prepared a surface coating of carbon fibre reinforced carbon composite using a layer of pyrolytic graphite and we used grinding and polishing of the layer for roughness control. The purpose of this article is to define the surface and surface roughness of carbon fibre reinforced carbon composite with and without a pyrolytic graphite layer and after defined surface treatment, and to correlate the results with several parameters of tissue cell growth. The main result of this work shows that, using the proper characterisation of the surface parameters, there is a statistically significant correlation with biocompatibility, especially, with adhesion and proliferation of cells. (C) 2003 Elsevier Science B.V. All rights reserved.