Sol-gel production of bioactive nanocoatings for medical applications. Part 1: an introduction

Coatings offer the possibility of modifying the surface properties of surgical-grade materials to achieve improvements in performance, reliability and biocompatibility. Sol-gel-derived coatings demonstrate promise owing to their relative ease of production, ability to form a physically and chemically pure and uniform coating over complex geometric shapes and potential to deliver exceptional mechanical properties owing to their nanocrystalline structure. Other advantages unique to sol-gel include the production of a homogeneous material, since mixing takes place on the atomic scale, and its relatively low processing temperature avoids decomposition of the coating materials and limits the damage to metallic substrate materials as a result of exposure to elevated temperatures. A range of materials can be adapted easily for a number of biomedical and engineering applications.