Cytotoxicity of novel titanium alloys aiming biomedical applications

Abstract

Titanium and its alloys are used in orthopedic and dental implants due to the appropriate characteristics of biocompatibility and high corrosion resistance and excellent mechanical strength/density ratio when compared to other metallic alloys used in the biomedical area. Among the titanium alloys used in Brazil and in the world for orthopedic implants, the most used is the Ti-6Al-4V alloy, since it has a very higher mechanical strength than pure titanium. In addition, implants that are present on the market are susceptible to degradation by mechanical wear, corrosion or tribocorrosion (joint corrosion action and mechanical wear), which is why they have a relatively short shelf life. However, Ti-6Al-4V alloy has elements considered cytotoxic: vanadium causes allergic reactions in human tissues and aluminum is associated with long-term neurological disorders. Therefore, searches for new alloys without these elements are being carried out. Alloys containing niobium, zirconium, molybdenum and tantalum are the most promising, since these elements are considered ²-stabilizers. Therefore, adding them to titanium changes its microstructure and mechanical properties, and may make it more efficient as biomaterial. In addition, it is important that these new materials stimulate, or do not interfere, in cell growth and expansion. Preliminary tests can be performed from the cell culture system, in which it is possible to thoroughly analyze cellular and extracellular matrix events (ECM). Thus, the main focus of this project is the study of in vitro cytotoxicity of new titanium-based alloys, aiming at biomedical applications, as well as to analyze the morphology of osteogenic cells in advanced periods.