Functionalizing Diatomite-Based Micro-Arc Coatings for Orthopedic Implants: Influence of TiO2 Addition

Abstract

The method of micro-arc oxidation has been utilized to synthesize a protective biocompatible coating for a bioresorbable orthopedic Mg implant. This paper presents the results of comprehensive research of micro-arc coatings based on diatomite—a biogenic material consisting of shells of diatom microalgae. The main focus of this study was the functionalization of diatomite-based micro-arc coatings by incorporating particles of titania (TiO2) into them. Various properties of the resulting coatings were examined and evaluated. XRD analysis revealed the formation of a new magnesium orthosilicate phase—forsterite (Mg2SiO4). It was established that the corrosion current density of the coatings decreased by 1–2 orders of magnitude after the inclusion of TiO2 particles, depending on the coating process voltage. The adhesion strength of the coatings increased following the particle incorporation. The processes of dissolution of both coated and uncoated samples in a sodium chloride solution were studied. The in vitro cell viability was assessed, which showed that the coatings significantly reduced the cytotoxicity of Mg samples.

Study of the Structural-Phase State of Hydroxyapatite Coatings Obtained by Detonation Spraying at Different O2/C2H2 Ratios

“…There are several common methods for this purpose including thermal spraying, immersion method, dynamic mixing, microarc oxidation, sol-gel method, pulsed laser deposition and many others [4][5][6][7][8]. Micro-arc oxidation (MAO, micro-arc oxidation) has recently become quite widespread due to the relative simplicity of the coating process [9,10]. Among other deposition methods, gasthermal methods are also widely used to create various biocompatible coatings.…”