Co-Optimization of in Vitro Biofunctionality and Electrochemical Passivity in Self-Doped TiO₂ Surfaces

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Titanium (Ti) is a widely used biomaterial, with its passive titanium dioxide (TiO2) film crucial for biofunctionality.
• The link between the semiconducting properties of TiO2 films and their biofunctionality is not well understood.

Purpose of the Study:

• To investigate the relationship between the semiconducting properties of TiO2 films and their biofunctionality.
• To fabricate self-doped TiO2 films on titanium using a novel additive-free method.

Main Methods:

• Hydrothermal oxidation in hydrogen peroxide to create self-doped TiO2 films.
• Thin-film X-ray diffraction and Raman microspectroscopy to characterize film properties.
• Electrochemical analysis to assess passivity and defect levels.

Main Results:

• Fabricated TiO2 films exhibited n-type semiconducting behavior due to oxygen deficiency (Ti3+).
• Moderate doping enhanced antibacterial activity and in vitro osteogenic functions.
• Prolonged treatment led to film cracking and reduced semiconducting properties.

Conclusions:

• Defect-mediated n-type semiconducting properties of TiO2 films are intrinsically linked to enhanced biofunctionality.
• Optimizing self-doping levels in TiO2 is critical for balancing biological performance and corrosion resistance in titanium biomaterials.