You shall not pass: Ti nanospike-based sterilizer in fluid flow reactor

We report the laser-ablative fabrication of antibacterial nanostructures, combining mechanical and chemotoxic effects, by femto- and nanosecond laser ablation and their testing on Staphylococcus aureus and Pseudomonas aeruginosa strains. A Ti surface, covered with nanospikes and periodical surface ripples, provides a strong anti-biofilm effect, and the addition of cytotoxic nanoparticles (NPs) (Ag, Se) enhances the overall bactericidal activities. A flow reactor, including Ti nanospike-covered wafers as a through-flow sterilizer, allowed reduction of the bacterial population by two orders. Several types of nanostructures with/without biofilms were characterized by scanning electron microscopy and energy-dispersive x-ray spectroscopy. Their antibacterial properties were demonstrated by standard live/dead tests and were suggested to originate from the combined chemical toxicity of NPs and mechanical damage caused by sharp nanoscale relief on Ti.

Automated summary

This study reported on the fabrication of antibacterial nanostructures using laser ablation, showing that nanospikes and periodic surface ripples on a Ti surface have strong anti-biofilm effects. The addition of cytotoxic nanoparticles (Ag, Se) further enhanced the bactericidal activities. The antibacterial properties of these nanostructures were demonstrated through live/dead tests, with the combination of chemical toxicity of nanoparticles and mechanical damage from sharp nanoscale relief on Ti being the primary mechanisms.