Antibacterial Performance of Zr-BMG, Stainless Steel, and Titanium Alloy with Laser-Induced Periodic Surface Structures

A laser-induced periodic surface structure (LIPSS) was shown to have antibacterial adhesion properties in previous research. In this study, the antibacterial performance of LIPSS on traditional biometals (stainless steel and titanium alloy) and a potential biometal (zirconium-based bulk metallic glass, Zr-BMG) was investigated. A femtosecond laser was used to fabricate LIPSS on the specimens. Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) were used to examine the antibacterial behavior of the LIPSS samples. The bacterial adhesion force on each specimen was evaluated by an atomic force microscopy (AFM) cell probe. The results showed that the LIPSS on all three metal surfaces significantly lowered antibacterial adhesion compared to polished metal specimens. E. coli demonstrated a higher adhesion force but a lower surface adhesion rate compared to S. aureus. The Zr-BMG specimen with LIPSS has multiple antimicrobial mechanisms (physical antiadhesion and chemical elimination), while the traditional biometals (316L and TC4) mainly offer physical antiadhesion. Finally, an in vitro/vivo study showed that specimens with LIPSS surfaces did not significantly affect the biocompatibility of the specimens. This study reveals that the Zr-BMG specimen with femtosecond laser-processed LIPSS is an ideal choice for achieving an antibacterial surface.