Abstract: Objective: To construct a TiO₂ nanotube coating that can release antibacterial peptide in a controlled manner on the surface of titanium. Methods: TiO₂ nanotubes were constructed on the surface of titanium by anodizing. The antibacterial peptide HHC-36 was combined with poly lactic-co-glycolic acid (PLGA) microspheres, and they were loaded on the TiO₂ nanotubes by double solvent emulsification and volatilization technology. The morphology of the specimens was observed with SEM. Release curve of the antibacterial peptide was investigated. The antibacterial activity of the experimental material was tested by observing and measuring the inhibition zone. Results: TiO₂ nanotubes with diameter of (100±20) nm were constructed on the surface of titanium. After PLGA-HHC-36 was loaded on the TiO₂ nanotube, microspheres with small pores could be observed with SEM. The experimental specimens showed sustained release of HHC-36 that lasted for at least 15 days. An inhibition zone with a diameter of 14 mm was observed around the experimental specimen and the inhibition zone showed no visible change after 10 days. Conclusion: A TiO₂ nanotube coating that can release antibacterial peptide in a controlled manner was successfully constructed on the surface of titanium. The experimental material revealed long-lasting antibacterial property.

Key words: TiO₂ nanotube, PLGA microsphere, antimicrobial coating, antibiotic peptide HHC-36