Antibacterial metal implant with a TiO₂‐conferred photocatalytic bactericidal effect against Staphylococcus aureus

Abstract

Photocatalysis with anatase Titanium dioxide (TiO 2 ) under ultraviolet A (UVA) has a well recognized bactericidal effect. There have been a few reports, however, on the effects of photocatalysis on bio-implant-related infections. The purpose of present study was to evaluate the photocatalytic bactericidal effects of anatase TiO 2 on Staphylococcus aureus (S. aureus) associated with surgical site infections.TiO 2 films were synthesized on commercially pure titanium substrates and SUS316 stainless steel using a plasma source ion implantation method followed by annealing. The chemical composition of the surface layers was determined using GXRD and XPS. The disks were seeded with cultured S. aureus and exposed to UVA illumination from black light. The bactericidal effect of the TiO 2 films was evaluated by counting the survived colonies statistically.A structural gradient anatase type TiO 2 layer formed on all substrates. The viability of the bacteria on the photocatalytic TiO 2 film coated on titanium was suppressed to 7.0% at 30 minutes and 5.5% at 45 minutes, whereas that on a similarly coated stainless steel was suppressed to 45.8% at 30 minute and 28.6% at 45 minutes (ANOVA: p < 0.05). Complete bacterial inactivation was achieved after 90 minutes on titanium and after 60 minutes on stainless steel. The photocatalytic bactericidal effect of TiO 2 is useful for sterilizing the contaminated surfaces of bioimplants.

Titanium Oxide Antibacterial Surfaces in Biomedical Devices

“…Negative pulses of 20 kV having a duration of 50 µs and a repetition rate of 100 Hz gave TiO 2 films with a thickness of 318 nm after annealing at temperatures between 673 K and 1023 K for 1 h. Similar results were obtained by Jing et al (110). Shiraishi et al (111) described the preparation of antibacterial metal implant (titanium and SUS316 stainless steel) with a TiO 2 using a plasma source ion implantation followed by annealing. The TiO 2 layer conferred photocatalytic bactericidal effect against S. aureus under UVA irradiation.…”

Stability and prospect of UV/H2O2 activated titania films for biomedical use

“…Systems penetrating soft tissue, such as bone anchored prostheses or dental implants, are particularly susceptible to infection due to high exposure to bacteria from the environment, and the application of antibiotics for combatting these infections in such cases may not be sufficient [11,32]. Reducing the general use of antibiotics to treat infection has also been a long standing call to limit bacterial resistance [33].…”

“…In applying the photocatalytic bactericidal properties of titania, an on-demand feature for decontamination can be added to biomedical surfaces, and is of particular interest for percutaneous implants and devices. A number of studies have been devoted to this matter and have shown promising results [4,11,[34][35][36][37], but further research is needed to improve efficiency and avoid adverse effects of UV light on healthy tissue, etc.…”

“…As a site-specific, non-antibiotic method, photocatalytic decontamination can also serve to reduce the spread of multiresistant bacteria [11].…”

Band-Gap Change and Photocatalytic Activity of Silica/Titania Composites Associated with Incorporation of CuO and NiO

“…Titania and TiO 2 based semiconductors are of a considerable interest as catalysts, sensors, implants, medical media, corrosion protectors and electronic components widely studied and used in a variety of physicochemical, biological and industrial processes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Introducing dopants of multifarious characters (metals, nonmetals) [16][17][18][19][20][21][22] involves the band gap narrowing of titania materials which gives rise to energy saving for diverse technological purposes.…”