In vitro study using calvaria-derived osteogenic primary cultures for evaluation of cytotoxicity of some Ti-based alloys for biomedical applications

摘要

Titanium and some of its alloys have been largely used in the production of prostheses and special medical and dental devices due to their properties, such as low Young's modulus values, corrosion resistance and biocompatibility. Provided that there are not adverse and no uncontrollable reactions are elicited in the biological system, the implanted material should be regarded as biocompatible. The in vitro cytotoxicity tests represent the initial step of the process, and could be considered as a pre-selection of those materials. This in vitro study aimed to evaluate the differentiation of calvaria-derived osteogenic primary cultures supplemented with ascorbic acid (AA$5 μg/mL)/p-glycerophosphate (βGP; 10 mM). It was analyzed the in vitro cytotoxicity as well as the differentiation of osteoblastic cells cultived on the Ti6Al4V, Ti1SZr5Mo, Ti15Zr10Mo e Ti15Zr15Mo alloys with different time periods. We have performed, to evaluate the cytotoxicity of the alloys, the assay MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenayl-2H-tetrazolium bromide) and scanning electron microscopy (SEM) with 24,48 and 72 hours. Besides to the mineralization nodules formation was analyzed by the assay alizarin red with 15 and 30 days as well as the alkaline phosphatase activity (ALP). The present results demonstrated that all alloys studied presented no cytotoxic effects on the osteogenic cells. In addition, the nodule mineralization formation was observed, as well as a high activity of alkaline phosphatase. All of them, independently from the material, showed a central and flattened cell body and numerous and long processes. Therefore these alloys no affected the in vitro proliferation, differentiation and biomineralization of osteoblastic cells, key characteristics to bone development.