Tunable morphological changes of asymmetric titanium nanosheets with bactericidal properties

Area of Science:

• Biomaterials science
• Surface engineering
• Nanotechnology

Background:

• Titanium and its alloys are preferred for medical implants but are prone to bacterial infections.
• Existing antibacterial strategies often involve antibiotics or coatings, which can lead to resistance.
• Surface nanotopography offers a physical mechanism for bacterial inactivation, reducing reliance on chemical agents.

Purpose of the Study:

• To investigate the relationship between hydrothermal etching time and the antibacterial efficacy of titanium surfaces.
• To optimize nanosheet morphology for enhanced mechano-bactericidal activity.
• To develop a physical antibacterial surface for medical implants.

Main Methods:

• Fabrication of bactericidal nanosheets on titanium surfaces using time-dependent hydrothermal processing.
• Systematic variation of hydrothermal etching times (0.5 to 60 hours).
• Evaluation of antibacterial efficiency against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria.

Main Results:

• Titanium surfaces etched for 6 hours demonstrated maximal antibacterial efficiency: 99%±3% against P. aeruginosa and 90%±9% against S. aureus.
• The most effective surfaces featured nanosheets with sharp edges approximately 10 nm in size.
• The developed nanotopographies exhibit superior mechano-bactericidal activity compared to previously reported nanostructured titanium surfaces.

Conclusions:

• Hydrothermal etching is an effective method for creating physically bactericidal titanium surfaces.
• Optimizing etching time allows for tuning nanosheet morphology and maximizing antibacterial efficacy.
• This approach presents a promising strategy for developing infection-resistant medical implants.