Cytotoxic and genotoxic study of in vitro released productos of stainless steel 316L with bioactive ceramic coatings

Abstract

The stainless steel AISI 316L is the must used biomaterial for the making of temporal prosthesis, but it presents severe limitations for permanent implants due to the generation and migration of metallic ions to the surrounding peripheral tissues, which produces oxygen reactive species (ERO) and damages of the ADN, increasing the possibility of local tumors and mechanical failure of the implant. A strategy used to minimize the generation of ions is the superficial modification of the implants by means of inorganic coatings, ceramic or vitreous, applied by the sol-gel process; this method has a series of comparative advantages, compared to other deposition methods, as good adherence, easy application, minimum drying problems, low densification temperatures and the possibility of adding particles and/or organic groups that improve the adhesion of the cell to the implant, increasing the biocompatibility. In the present work, the citotoxic effects were valuated by means of the MTT technique, and the genotoxic ones by electrophoresis of individual cell gels (Cometa test), on CHO cells, of the released products in a MEM media, after a period of 30 days, of the stainless steel 316L with no coat, coated with a coat of silica glass (MC), or with two coats of the same glass, containing bioactive particles of hydroxyapatite (HA), glass (V) or glassceramic powder (VC). The results show that there is not citotoxic effects in a test with an aging of 30 days in MEM media; a genotoxic effect was found in the A and MC samples, but without real risk for cell systems.