Effects of MgF2 coating on the biodegradation and biological properties of magnesium

Abstract

The rapid degradation rate has been a hindrance to promote the clinical application of biodegradable magnesium (Mg). To solve this problem, researchers have devoted to the surface modification of Mg for years. Magnesium fluoride (MgF2) coating is easy to obtain and has excellent corrosion resistance, which has long-term research value in surface modification of magnesium implants. However, we are still lacking in understanding the influence of process parameters, sizes of film and other factors on the protective effect of MgF2 coating, and its biocompatibility also needs to be verified. In this paper, the sizes, corrosion resistance and biocompatibility of the chemical conversion film (MgF2) with different preparation time were studied. Through in vitro immersion, electrochemical simulation, structure and composition analysis and cytotoxicity test, we derived the rules that the MgF2 film with greater thickness and better corrosion resistance was prepared under longer preparation time. The differences of several characterization methods were compared. Meanwhile, we demonstrated that the MgF2 film had great cytocompatibility and the attachment and growth of osteoblasts on the surface of the film were quite satisfied. These conclusions are of great significance for the applications of the MgF2 film in orthopedic clinical implantation.