Enhanced Corrosion Resistance and Biocompatibility of NaMgF3 Coating on Mg-Zn-Ca Alloy: An In Vivo and In Vitro Study

The objective of the present work is to investigate the in vitro and in vivo performance of NaMgF3 coating on Mg-3Zn-0.2Ca (MZC) alloy for bone applications. NaMgF3 coating is developed on MZC alloy by using NaF solution, which prepares the F(-)containing coating while avoiding the use of hydrofluoric acid, which is of higher toxicity. The dense NaMgF3 coating with a thickness of approximate to 20 mu m contributes to reducing the corrosion rate of MZC exposed to Hanks' solution by approximate to 43% from 0.7 to 0.4 mm y(-1). The NaMgF3 coating also depresses the corrosion rate of MZC in vivo, causing the residual volume of the implanted MZC rods to increase from below 70% to approximate to 90%. Besides, the toughness value of MZC rods coated with NaMgF3 after implantation is 2780 MJ m(-3), which demonstrates the continuous and sufficient mechanical support that is provided by it for bone repair. Importantly, osteoblasts can adhere and differentiate on the coating surface, and the NaMgF3 coating enhanced the biocompatibility and osteogenesis of the MZC alloy. So, the NaMgF3-coated MZC alloy could be used in bone repair applications.