Enhanced antibacterial activity of Ti-Cu alloy by selective acid etching

Titanium-copper (Ti-Cu) alloys showed potential application in clinical field due to their excellent antibacterial properties. A selective acid etching (SAE) was applied to Ti-Cu alloy in order to further improve the antibacterial properties. The phase constitute and the surface microstructure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), the corrosion properties and Cu ion release behavior were measured by electrochemical testing and inductively coupled plasma spectrometry (ICP), the antibacterial property was assessed by a plate-count method and the cell compatibility was evaluated by CCK-8 test. It was shown that more Ti2Cu particles were exposed on the surface of Ti-Cu sample after SAE treatment, which increased the corrosion current density and accelerated the Cu ion release due to the galvanic corrosion between Ti-Ti2Cu couple. The plate counting results demonstrated that the antibacterial ability of Ti-Cu alloy was significantly enhanced from 79% to >99.9% by SAE treatment due to the multifunction of increased Ti2Cu phase on the surface, Cu ion release and the formation of Cu2O. Besides, no cytotoxicity was detected to MC3T3-E1 cells on all test samples.

Automated summary

The antibacterial properties of titanium-copper (Ti-Cu) alloys were significantly enhanced through selective acid etching treatment, which exposed more Ti2Cu particles on the surface, accelerated the release of copper ions, and formed Cu2O, without exhibiting cytotoxicity on cells.