Fabrication of an antibacterial zinc oxide film on biodegradable magnesium alloy and its biocompatibility

To avoid the rapid degradation of magnesium alloy AZ31B after implantation in the body, the addition of a zinc oxide (ZnO) film was examined. A rough surface was fabricated by femtosecond laser on AZ31B at frequencies of 100, 200, 300, 500, and 800 kHz, before adding a ZnO film by wet metallurgy. Scanning electron microscopy (SEM) indicated that 500 kHz femtosecond laser frequency produced a coral-like surface morphology on AZ31B and the ZnO film had a needle-like structure. X-ray diffraction (XRD) revealed that the film mainly consisted of Zn and ZnO. Potentiodynamic polarization curves revealed that the ZnO film exhibited a better corrosion resistance than bare AZ31B. It also possessed superior cell proliferation ability and higher suppression of a representative device-related infection of Escherichia coli strain than bare AZ31B. This study provides a novel film strategy for manufacturing biodegradable magnesium alloys with good corrosion resistance, biocompatibility, and antibacterial properties.