Degradation characteristics and cytocompatibility performance of hydroxyapatite/graphene oxide composite coated pure Mg in physiological environment

Despite being a promising bone implant material, pure magnesium (Mg) has limited clinical application due to its high corrosion rate, mechanical instability, and excess hydrogen evolution in physiological solutions. Herein, a hydroxyapatite (HA) coating and a hydroxyapatite/graphene oxide (HA/GO) composite coating were fabricated on pure Mg surface through electrochemical deposition. The samples were then assessed and characterized in vitro to evaluate their degradation characteristics and cytocompatibility performance using advanced characterization and electrochemical techniques, combined with cell culture assays under physiological conditions. The results revealed that the HA/GO composite coating induced uniform growth of apatite on the Mg surface, significantly enhancing the corrosion resistant of Mg, thereby suppressing hydrogen evolution in simulated body fluid (SBF) solution. Moreover, in vitro biocompatibility test exhibited that the HA/GO composite coating enhanced the intercellular activity of rBMSC cells by providing a favorable environment. This effect is attributed to the presence of multiple chelating sites in GO, which facilitates improved proliferation and osteogenic differentiation.