Antibacterial and osteogenic stem cell differentiation properties of photoinduced TiO₂ nanoparticle-decorated TiO₂ nanotubes.

Abstract

To improve the antibacterial and mammalian cell compatibility properties of titania nanotubes (TNTs) anodized into titanium (Ti). 3-8-nm TiO2 nanoparticles were decorated on the surface and inside TNT (TNT-TiO2) through a hydrothermal method. After UV light treatment, two types of oral bacteria and stem cells were cultured on the samples to determine antibacterial and compatibility properties. TiO2 nanoparticles increased the surface area and photocatalysis of TNTs. Based on the photocatalysis effect and prolonged photo-induced wettability, the numbers of Streptococcus mutans and Porphyromonas gingivalis were lower on the surface of TNT-TiO2 than pure Ti and TNTs after the first 7 days. Specifically, for S. mutans, the glycosytransferase (gtf) genes were downregulated 0.1-0.2-fold on TNT-TiO2. Due to the different topography and high surface energy of TNT-TiO2, stem cells also showed improved osteogenic functions on TNT-TiO2. In this study, we demonstrated for the first time improved antibacterial properties and, at the same time, greater stem cell osteogenic capacity when decorating TNTs with nanosized TiO2 particles, which may significantly improve orthopedic and dental implant efficacy.