Biomimetic Coatings on Orthopedic Implants: a Review

Abstract

AbstractIn bone replacement surgery, replacement of joints (of hip, knee, finger and jaw) is a major sub discipline, requiring mechanically strong and biologically compatible, or biocompatible, implants. Since mechanical strength can only be achieved with metals that lack the required biocompatibility, surface treatments to improve that lack have been studied extensively. Since the mineral phase of bone consists of various calcium salts, the most relevant one being (carbonated) apatite, the surface treatments of choice are coatings of such salts on orthopedic implants have been successfully developed. (Bulk ceramics of CaP are too brittle to be used for load bearing implants). Although currently used coatings as obtained by plasma spraying have been highly successful, the high temperature and line-of-sight nature of the plasma spray process prevent (1) coatings to be deposited on implants made of polymer composites, (2) coatings to be deposited on complex surfaces and/or within porous implants and (3) biological molecules such as growth factors or antibiotics to be included in the coating. Therefore, we and several other research groups have focussed our attention to so called biomimetic coatings, that are produced at ambient temperature by a precipitation process from fluids resembling body fluids in their inorganic composition. In this presentation, we will give a review of some current developments on biomimetic coatings.