MOUSE INFLAMMATORY RESPONSE TO STAINLESS-STEEL CORROSION PRODUCTS

Corrosion occurs regularly following long-term implantation of stainle ss steel. Little is known about the inflammatory and immunological pot ential of stainless steel corrosion products. AISI 316L stainless stee l was anodically dissolved in a physiologically solution, HBSS, throug h a chronoamperometric process by imposing an external constant curren t of 0.5 mA. The solution, containing 245 mu g of Fe, 112 mu g of Cr, 75 mu g of Ni and 13 mu g of Mo, was injected in the peritoneal cavity of male C57BL/6 mice. Five animals were used per survival period of t ime: 4, 16, 24, and 48 h, 1, 2, 4, 8 and 16 weeks. Three control mice per survival period of time were injected with HBSS. For each assay, p eritoneal samples were analysed not only for the total number of cells but also for the percentages of macrophages, lymphocytes and polymorp honuclear (PMN) cells, which were estimated by differential counting o n Wright-stained cytocentrifuge preparations. Our follow-up study show ed that stainless steel corrosion products induced an acute inflammato ry response for a period of one week as demonstrated by the influx of PMN cells and macrophages. In contrast neither a chronic inflammation nor an immune response was observed indicating that the stainless stee l solution caused a minor tissue response.