Antibacterial activity of copper-bearing 316L stainless steel for the prevention of implant-related infection.

Implant-related infection (IRI) is a devastating complication in orthopedic procedures. Traditional materials used in orthopedics are susceptible to bacterial infection. In this study, we developed a copper-bearing 316L stainless steel (316L-Cu SS) for the prevention of IRI. This 316L-Cu SS allowed stable and continuous release of copper ions with a rate of 5.079 ng/cm² /day. Compared with 316L stainless steel (316L SS), 316L-Cu SS exhibited a broad-spectrum antibacterial effect against Staphylococcus aureus, Escherichia coli, and Staphylococcus epidermidis with the bacterial reduction percentages of 95.2, 94.8, and 94.1%, respectively. The antibiofilm activity was confirmed by crystal violet assay, scanning electron microscopy, and confocal laser scanning microscopy. The in vivo antibacterial performance was tested on a rat model. When nails were treated with a low concentration of bacteria, 316L SS group exhibit a bone infection with a radiographic score of 8.9 ± 1.1 and a histological score of 10.4 ± 1.0, which were higher than 316L-Cu SS group (1.2 ± 0.2 and 0.9 ± 0.2), indicating IRI was reduced by 316L-Cu SS. When nails were treated with a high concentration of bacteria, IRI was also alleviated by 316L-Cu SS. Together, these results demonstrated that 316L-Cu SS is a promising material for preventing IRI.