Inhibition of Staphylococcus aureus biofilm by a copper-bearing 317L-Cu stainless steel and its corrosion resistance

• The 317L-Cu SS with excellent biocidal effect has been designed and manufactured.
• The Zebra fish model was introduced to evaluate the cytotoxicity of 317L-Cu SS.
• The copper addition did not significantly decrease the corrosion resistance of the 317L-Cu SS.

The present study investigated the antibacterial performance, corrosion resistance and surface properties of antibacterial austenitic 317L-Cu stainless steel (317L-Cu SS). After 4.5 wt% copper was added to 317L stainless steel (317L SS), the new alloy underwent solid solution and aging heat treatment. Fluorescent staining using 4′,6-diamidino-2-phenylindole (DAPI) revealed that the 317L-Cu SS showed strong antibacterial efficacy, achieving a 99% inhibition rate of sessile Staphylococcus aureus cells after 5 days. The corrosion data obtained by potentiodynamic polarization curves indicated that in comparison with 317L SS, the pitting potential and corrosion current density of 317L-Cu slightly decreased due to the addition of Cu. The 317L-Cu SS exhibited no cytotoxicity against zebrafish (Danio rerio) embryos. The experimental results in this study demonstrated that the new alloy has potential applications in medical and daily uses.