Magnesium alloys are ideal materials in clinical applications
for
their excellent mechanical properties, while potential cytotoxicity
with rapid degradation limits their clinical applications. Moreover,
it is also important for implants to avoid inflammation caused by
bacterial infections in the early stage of implantation. Therefore,
copper-doped anhydrous calcium phosphate nanoparticles were fabricated
by the hydrothermal method and dispersed in a dicalcium phosphate
dihydrate (DCPD)/Polycaprolactone (PCL) composite coating to improve
its bacteriostatic properties, corrosion resistance, and biocompatibility
in this paper. The impedance of the DCPD/PCL/Cu-doped anhydrous calcium
phosphate (Cu-ADCP) composite-coated sample is 1 order of magnitude
higher than that of the bare magnesium alloy, and the corrosion current
density decreases by 2 orders of magnitude, indicating that the composite
coating incorporating nanoparticles can effectively enhance the corrosion
resistance. The in vitro cell experiments show its biocompatibility
with sustained growth in cellular activity and increased alkaline
phosphatase activity. Most importantly, the embedded copper-doped
nanoparticles significantly improve the antibacterial properties of
the composite coating. Compared with the composite coating with almost
no antibacterial ability, the antibacterial rate reached 96 and 98%
for Escherichia coli and Staphylococcus aureus, respectively, after the nanoparticles
were embedded, making them a promising choice for orthopedic applications.