Corrosion Inhibition of Orthopedic Implants with Antioxidants

The demand for orthopedic implants will continue to rise, as millions of people need it to alleviate pain and increase mobility concerns lost due to joint related disorders. Though largely successful, cases of implant failure remain as cases of aseptic loosening and periprosthetic osteolysis resulting from wear particles and metal ions accelerate harmful processes that detach the implant from its environment. Wear particles and metal ions are degradation products resulting from processes like corrosion. To lessen the concern of corrosion for titanium and other metallic implants, antioxidants that are anti-inflammatory in nature are being researched as potential corrosion inhibitors. In this study, vitamin E and curcumin are present in solutions of bovine calf serum (BCS) at different concentrations of 0.05, 0.5, and 1.0 µg/mL to test the corrosion resistance of Ti-6Al-4V samples. The aims of this project include the assessment of vitamin E as a corrosion inhibitor, the evaluation of curcumin as a corrosion inhibitor, and the determination of curcumin or vitamin E as the more effective corrosion inhibitor. By using electrochemical corrosion characterization and surface characterization methods such as Scanning Electron Microscopy (SEM) and 3D profilometry, the effect of these antioxidants as corrosion inhibitors will be evaluated and compared based on parameters such as corrosion current density, corrosion potential, polarization resistance, and double layer capacitance values, as well as surface roughness and inhibition efficiency. The novelty in this work is that corrosion research has not been done so far with vitamin E, curcumin, and titanium samples in a small range (µg/mL). Our results showed that both higher concentrations of curcumin and vitamin E present in BCS displayed more corrosion resistance and higher inhibitor efficiencies compared to the control. It is hypothesized that curcumin and vitamin E formed protective films on the Ti-6Al-4V surface, but curcumin had the greater protection in lower concentrations than vitamin E, awarding it as the more effective inhibitor. More research is needed to further investigate concentrations of vitamin E and curcumin to increase inhibitor efficiencies, as well as performing toxicity tests, and exploring methods to incorporate antioxidants into implant design.