Anin vitroandin vivocomparison of Mg(OH)2-, MgF2- and HA-coated Mg in degradation and osteointegration

Magnesium hydroxide (Mg(OH)(2)), magnesium fluoride (MgF2), and hydroxyapatite (HA) films on Mg are widely studied owing to their easy preparation and favorable corrosion protection. Nevertheless, the most suitable film with the best performance for biomedical applications between the three films remains unknown. Therefore, the performance of the three coatings fromin vitrotoin vivomust be systematically investigated. In this study, Mg(OH)(2), MgF2, and HA films were fabricated on pure Mg. Electrochemical analysis and the hydrogen evolution test suggested that the HA film showed the bestin vitrocorrosion resistance, followed by MgF(2)and Mg(OH)(2)films.In vitrocell culture indicated that the extract of the MgF2-coated sample was most beneficial for the osteogenic differentiation of MC3T3-E1 cells and the vascularization of human umbilical vein endothelial cells (HUVECs), which might be ascribed to the existence of the F element in the film. The result of this subcutaneous implantation showed that the HA film exhibited the bestin vivocorrosion resistance and induced the lightest inflammatory response. Femoral implantation data revealed that the HA film exhibited the best osseointegration. Furthermore, the major organs and blood indicators of all of the tested rats were normal in 8 weeks. In summary, though thein vitrobiological performance of the MgF(2)film was the best among the three films, the HA film showed the bestin vivoperformance, suggesting that it is a more promising modification method for orthopedic applications.