Implanting a Copper Ion into a TiO2Nanorod Array for the Investigation on the Synergistic Antibacterial Mechanism between Mechanical Cracking and Chemical Damage

Titanium (Ti) and its alloys are extensively applied in dental and orthopedic implants due to their characteristics of goodmechanical property and corrosion resistance. However, Ti and its alloyssuffer from the absence of certain biological activity and antibacterialability. Herein, we synthesized a titanium dioxide (TiO2) nanorod array onthe surface of a Ti plate, and the obtained TiO2nanorod array was furthermodified by Cu ions through ion implantation technology in an attempt toendow medical Ti with an antibacterial ability and maintain a normalbiological function synchronously. The antibacterial ability of the TiO2nanorod array with the incorporation of Cu ions was vastly improvedcompared with those of the unmodified TiO2nanorod array and pure Ti.In particular, owing to the synergy between the chemical damage of thereleased Cu2+to the cell and the mechanical cracking of the TiO2nanorodarray, the antibacterial rate of the TiO2nanorod array modified by Cu ionsagainstEscherichia coliorStaphylococcus aureuscould reach 99%. In addition, no cytotoxicity was detected in such prepared coatingduring the CCK-8 assay. Moreover, the corrosion resistance of the sample was significantly better than that of pure Ti. Overall, wedemonstrated that the application of ion implantation technology could open up a promising pathway to design and develop further antibacterial material for the biomedical domain