Enhanced degradation performance and promoted bone regeneration of novel CaCO3-based hybrid coatings on magnesium alloy as bioresorbable orthopedic implants.

[Display omitted] • Novel CaCO 3 hybrid coatings are firstly evaluated in vitro and in vivo on orthopedic Mg alloys. • Glu significantly optimizes the composition and morphology of CaCO 3 coating. • CaCO 3 -based coatings largely inhibit the in vitro and in vivo degradation of Mg alloy. • CaCO 3 @Glu hybrid coating exhibits accelerated osteogenesis in vitro and in vivo. Fast degradation of Mg alloys and slow bone regeneration process largely impede their clinical applications as one kind of degradable metallic orthopedic implants. In current study, novel calcium carbonate (CaCO 3) coatings are prepared via the hydrothermal method and optimized via the addition of glutamate acid (Glu) or dopamine (DOPA) to improve the degradation and biological performance of the MgZnCa alloy. The results revealed that the CaCO 3 coating was mainly composed of rhombohedral calcite aggregates and deposited rod-like aragonite. Whereas, the introduction of Glu or DOPA stabilized plate-like vaterite via the adsorption or incorporation of organic molecules, and suppressed the deposition of rod-like aragonite on CaCO 3 hybrid coating with lower roughness, higher adhesion strength and thickness. Thus, CaCO 3 hybrid coatings endowed the MgZnCa alloy with more favorable in vitro degradation resistance. Furthermore, all CaCO 3 -based coatings showed good in vitro cytocompatibility, while CaCO 3 @Glu hybrid coating exhibited the best in vitro osteogenic activity of osteoblasts, attesting the synergistic effect of Glu and vaterite on the biological activity of the MgZnCa alloy. In vivo results verified the significantly inhibited degradation and promoted osteogenesis of the CaCO 3 @Glu hybrid coating. These results provide important guidelines and rationality for the further application of the CaCO 3 -based coatings on orthopedic implants towards more excellent clinical performance. [ABSTRACT FROM AUTHOR]