Preparation of sonoactivated TiO₂-DVDMS nanocomposite for enhanced antibacterial activity

Titanium dioxide (TiO₂) nanoparticle has good photo-/sono-catalytic features, the reunion of this particle in solution-phase generally limits the extensive biomedical application. In the present study, the aggregation of TiO₂ nanoparticles was alleviated by facile fabrication under different pH conditions. A novel TiO₂ nanocomposite was further synthesized by properly conjugation with trace amount of DVDMS sensitizer (named DFT). The characterization, sonoactivity, as well as the antibacterial efficiency were specially evaluated. The results showed that the sonochemical activity of DFT was greatly improved as compared with the simple surface modification of TiO₂ (F-TiO₂) and free DVDMS, regarding to the hydroxyl radicals and singlet oxygen yields using the same ultrasound exposure. Moreover, ultrasonic stimulation of DFT exhibited excellent bacterial eradication, with up to 92.41% of killing efficiency in S. aureus. The flow cytometry analysis indicated an increased intracellular ROS and membrane disturbance by combination of DFT and ultrasound. The findings suggest that the proper fabrication and DVDMS incorporation greatly improved the sonocatalytic process of TiO₂, and the ultrasound based biomedical applications of DFT deserve future deep investigation.