SiNtx Technologies Inc (SINT)

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Time-dependent Enhanced Corrosion of Ti6Al4V in the Presence of H2O2 and Albumin

The long term dissolution behaviour in the presence of albumin and H2O2 can be attributed to the enhanced dissolution of peroxide corrosion products in the presence of albumin, resulting in formation of a thinner oxide layer on the metal surface.

The rate of metal ion release in the presence of albumin and H2O2 was found to depend on potential. At lower potential, a higher metal ion release rate was observed via ICP-MS measurements, and the oxide resistance and capacitance determined from EIS was consistent with a thinner oxide layer than that found at higher potentials.

The corrosion rate of Ti6Al4V in the presence of albumin and H2O2 in 0.15?M NaCl was observed to be significantly higher than that in 0.15?M NaCl alone, emphasising the need to test alloys for biomedical implants in more realistic physiological solutions. It is also essential to make measurements over longer time periods than those typically performed in standard tests involving conventional polarisation curves.

https://www.nature.com/articles/s41598-018-21332-x

Yet another study showing how flawed in-vitro models are. The addition of albumin led to the reduction in the oxide layer of Ti implant over time. Without the oxide layer titanium loses is best defense against corrosion. Consequently its the degradation of the oxide layer that leads to increased Titanium Dioxide in blood.

The second study shows increased corrosion when porous titanium is exposed to an electrolyte only. Judging from the first study, this 2nd study underestimates the occurance of corrosion because they do not factor in albumin into their testing.

In vitro studying corrosion behavior of porous titanium coating in dynamic electrolyte.

The studies of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) show that the pores in the PT play a negetive part in corrosion resistance and the flowing electrolyte can increase the corrosive rate of all titanium samples. The results suggest that pore design of titanium implants should pay attention to the effect of dynamic process of a physiological environment on the corrosion behavior of implants.

https://www.ncbi.nlm.nih.gov/m/pubmed/27772706/