Enhanced corrosion resistance and biocompatibility of magnesium alloy by hydroxyapatite/graphene oxide bilayer coating

Fast degradation is the major limitation for biomedical application of Mg alloy. In the current work, a bilayer coating (HA/GO#) with hydroxyapatite as the inner layer and graphene oxide as the out layer was prepared on AZ31 alloy. Graphene oxide could sufficiently inhibit the formation and growth of corrosion cracks on hydroxyapatite layer, which result in its superior corrosion resistance. In vitro cell viability results suggested that MC3T3-E1 cells exhibited larger spreading area on HA/GO# coating at the initial 4 h of incubation. Furthermore, cells on HA/GO# coating showed superior proliferation rate. Considering its satisfied corrosion resistance and biocompatibility, the as prepared bilayer coating on AZ31 alloy is promising for clinical application. (C) 2020 Elsevier B.V. All rights reserved.