Surface Nanocrystallization for Bacterial Control

Stainless steel is commonly used in indwelling medical devices, food preparation, and heavy industry. Bacteria display reduced adherence to nanocrystallized stainless steel. In this article, we present quantitative information on the surface adhesive force, surface electron work function, and bacterial adherence to surfaces of nanocrystallized stainless steel with differing grain sizes. Surface nanocrystallization was achieved by sandblasting followed by recovery treatment. The adhesive force of bacterial binding to nanocrystallized surfaces was measured using an atomic force microscope with a synthetic-peptide-coated AFM tip designed to mimic the bacterial binding site of Pseudomonas aeruginosa, a common pathogen known to form biofilms. The electron work function of the steel surfaces was measured, and bacterial binding assays were performed using subinoculated P. aeruginosa cultures. It was demonstrated that for nanograined steel surfaces, the adhesive force, peptide adherence, surface electron activity, and bacterial binding all decreased with decreasing grain size.