RRC ID 87517
Author Kojima T, Tanaka R, Zhou J, Fukamachi H, Yoshimura K, Sugamori Y, Kobayashi H, Nonaka N, Kuwata H, Munakata M, Shibata Y.
Title Co-Optimization of in Vitro Biofunctionality and Electrochemical Passivity in Self-Doped TiO2 Surfaces.
Journal ACS Omega
Abstract Titanium is a well-established biomaterial, with its passive oxide film playing a key role in regulating interfacial chemistry and biofunctionality. However, the relationship between the biofunctionality of the passive TiO2 film and its semiconducting properties remains underexplored. To address this gap, self-doped TiO2 was fabricated on titanium via hydrothermal oxidation in hydrogen peroxide. This additive-free approach enabled the intrinsic effects of semiconducting behavior to be studied independently. Thin-film X-ray diffraction and Raman microspectroscopy identified partial reduction of Ti4+ to Ti3+, consistent with the formation of oxygen-deficient states characteristic of n-type semiconductors. Treatment conditions were varied to control the defect level. Moderate treatment produced a pronounced n-type character while preserving electrochemical passivity, whereas prolonged treatment yielded thicker, cracked films with reduced semiconducting response. The modified surfaces exhibited antibacterial activities against Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and promoted in vitro osteogenic functions, including upregulation of the redox-responsive genes Hic-5 and Sod2. These results demonstrate that defect-mediated n-type semiconducting properties are closely linked to biofunctionality, and that tuning self-doping to moderate levels is the key for co-optimizing the biological performance and corrosion resistance of titanium.
Volume 11(4)
Pages 6718-6727
Published 2026-2-3
DOI 10.1021/acsomega.5c12292
PMID 41658110
PMC PMC12878777
Resource
Human and Animal Cells MC3T3-E1(RCB1126)