Electrochemical testing of a novel alloy in natural and artificial body fluids.

There is a recent trend in tissue engineering and regenerative medicine to use nanotechnology and bionanomaterials to obtain materials that mimic the surface properties of a natural tissue. From this perspective, nanolevel tissue engineering can be viewed as a novel anatomy of the future. In this paper, a novel titanium-based alloy is studied following this strategy. The alloy nanostructuration is proposed as an improved alternative for restorative prosthodontics or an implantable biomaterial. Tests in (i) standard solution of simulated body fluid (SBF) and (ii) natural saliva were performed to investigate the alloy's electrochemical stability. The results show that nanochannel growth on the alloy surface confers a higher stability than that of the untreated one in both natural and simulated environments.

Enhancement of the electrochemical behaviour and biological performance of Ti-25Ta-5Zr alloy by thermo-mechanical processing.

A new Ti-25Ta-5Zr alloy based only on non-toxic and non-allergic elements was elaborated in as-cast and thermo-mechanical processed, recrystallized states (XRD and SEM) in order to be used as candidate material for implant applications. Its long-term interactions with Ringer-Brown and Ringer solutions of different pH values and its cytocompatibility were determined. The thermo-mechanically processed alloy has nobler electrochemical behaviour than as-cast alloy due to finer microstructure obtained after the applied treatment. Corrosion and ion release rates presented the lowest values for the treated alloy. Nyquist and Bode plots displayed higher impedance values and phase angles for the processed alloy, denoting a more protective passive film. SEM micrographs revealed depositions from solutions that contain calcium, phosphorous and oxygen ions (EDX analysis), namely calcium phosphate. An electric equivalent circuit with two time constants was modelled. Cell culture experiments with MC3T3-E1 pre-osteoblasts demonstrated that thermo-mechanically processed Ti-25Ta-5Zr alloy supports a better cell adhesion and spreading, and enhanced cell proliferation. Altogether, these data indicate that thermo-mechanical treatment endows the alloy with improved anticorrosion and biological performances.