In-vitro analysis of metallic particles, colloidal nanoparticles and ions in wear-corrosion products of SUS317L stainless steel

The present study attempts to clarify the relative cytotoxic levels of ions, colloidal nanoparticles, and metallic particles found in wear-corrosion products of SUS317L stainless steel. The wear-corrosion products were generated in pin-on-plate wear tests in a calcium-magnesium-free phosphate buffered saline solution (PBS(−)). Of all the particles and ions generated by wear-corrosion, colloidal nanoparticles induced maximum cytotoxicity. Metallic particles were much better tolerated than colloidal nanoparticles. Levels of iron and chromium ions released into the PBS(−) solution were too low to induce cytotoxic effects. Cytotoxic effects due to nickel were still smaller than those due to the colloidal nanoparticles. These nanoparticles consisted mainly of phosphate-containing amorphous iron hydroxide formed by precipitation, and possibly mechanochemical reaction during wear-corrosion.