Electrodeposition of hydroxyapatite on 3D surfaces

Abstract

Titanium and its alloys have been frequently employed in many orthopedic and implant applications. In order to provide bioactivity to these materials, as well as enhance osteointegration, their surfaces are usually coated with hydroxyapatite (HAp). Adhesion of bone cells to the implant surface, bond strength and durability of the implants are highly dependent on the characteristics of the Ti substrate and the methods used in the hydroxyapatite coating process. Compared to other methods, anodic oxidation for preparing TiO2 nanotube arrays has attracted more and more attention due to its simplicity, low cost, self-ordering process, and the ease of controlling the nanotube morphology by changing anodization conditions. Anodization to form tube layers is usually carried out by applying a potential step at a constant voltage in aqueous electrolyte containing fluoride ions. The electrochemical anodization is self-organizing: it leads to an array of oxide nanotubes aligned perpendicularly to the substrate surface and to a well-defined tube length. The tubes are attached to the metal surface and are thus already electrically connected. In this project, which will be held on the Laboratory of Electrochemical and Physicochemical Materials and Interfaces (LEPMI - Grenoble, France) under the supervision of Prof. Dr. Ricardo Pereira Nogueira and Dr. Virginie Roche, titanium substrates will be anodized to create a TiO2 nanotube layer on their surfaces, which can significantly stimulate apatite formation. Hydroxyapatite will be electroplated onto the surface of the nanotubes. The kinetic of this deposition will be studied. (AU)