Magnesium alloy with superhydrophilic magnesium/gallium-layered double hydroxides coating with antibacterial property as implant material

Bacterial infection of an implant can cause implant failure and lead to complications. Magnesium and its alloys have been selected as implant materials, since they are biodegradable and possess suitable elastic moduli. However, the rapid rate of degradation of magnesium and its alloys in the body, as well as attachment of bacterial cells on their surfaces, limits their application as implants. Therefore, this paper reports a superhydrophilic magnesium/gallium-layered double hydroxides (SH/Mg-Ga LDHs) coating. The SH/Mg-Ga LDHs coating exhibited excellent superhydrophilic properties and prevented bacterial attachment on the surface of magnesium alloy. Furthermore, the coating demonstrated outstanding antibacterial performance, with inhibition rates exceeding 99% against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Additionally, the coating reduced the corrosion current density of the magnesium alloy from 7.49 × 10^–6 to 1.67 × 10^–7 A/cm², and increased the corrosion potential from − 1.55 V/SCE to − 0.35 V/SCE, thereby significantly improving the corrosion resistance of the magnesium alloy. The number of platelets adhering to the coating was nearly zero, and the thrombosis index increased from 92 to 96%, effectively preventing thrombus formation. Therefore, the Mg-Ga LDHs coating provided a feasible solution to improve the properties of magnesium alloy implant materials and promote the application of magnesium alloys.