Antibacterial Performance and Cytocompatibility of Hierarchically Textured 316LVM Stainless Steel Modified by Cathodic Plasma Electrolytic Oxidation, Acid Etching, and Copper Containing Coating

Abstract

Implant‐associated infections remain a major challenge for stainless steel (SS) biomaterials because bacterial adhesion and biofilm formation can compromise clinical performance. This study investigated a hierarchical surface treatment for 316LVM SS combining cathodic plasma electrolytic oxidation (CPEO), acid etching (ET), and a copper‐based coating to improve antibacterial activity while preserving cytocompatibility. CPEO generated a microstructured oxide surface, acid ET introduced additional nanoscale features, and CuO deposition provided surface chemical functionalization. The modified surfaces were characterized in terms of morphology, roughness, wettability, surface chemistry, and electrochemical behavior, and their antibacterial and cytocompatibility performance were evaluated against Staphylococcus aureus and human dental pulp stem cells (hDPSCs). Among the tested conditions, the CPEO + ET + CuO surface showed the strongest antibacterial effect, reducing bacterial adhesion. Cell viability remained acceptable at the initial evaluation times, although a slight reduction was observed for the Cu‐containing layer on day 7, suggesting a time‐dependent response. Electrochemical tests showed that the surface modification route did not impair the corrosion resistance of 316LVM SS and, for some conditions, promoted improved corrosion behavior. These findings indicate that hierarchical texturing followed by a Cu‐containing layer is a promising strategy for improving the antibacterial performance of 316LVM SS while preserving cytocompatibility and corrosion behavior.