Low temperature preparation of phase-tunable and antimicrobial titanium dioxide coating on biomedical polymer implants for reducing implant-related infections

In light of the photocatalytic and antimicrobial properties of titanium dioxide (TiO2), this study deposited thin coatings of TiO2 onto a substrate of polymeric polyetheretherketone (PEEK) using a novel arc ion plating (AIP) method. This paper also describes the precise mechanism behind the antimicrobial properties resulting from the crystal structure of TiO2. Experimental results demonstrated that in preparing the TiO2 coatings, adjusting the target current and substrate bias during deposition enabled the control of the ratio of anatase to rutile crystalline structures in the coating, to attain anatase content between 9.1 and 92.7%. Under typical fluorescent lamp lighting conditions, the TiO2 coatings rich in anatase had superior photocatalytic and, consequently, antimicrobial properties relative to coatings rich in rutile. The TiO2 coatings were deposited without damaging the substrate of polymeric PEEK.

Research highlights
► This study fabricated AIP–TiO2 coatings on a PEEK substrate without any damage.
► The proportion of A–TiO2 to R–TiO2 in the deposited films can be controlled.
► The antimicrobial effectiveness of TiO2 are determined by the proportion of A–TiO2.
► The infection problem could be improved, through the surface modification technique.