Micro/nano-structured TiO₂ surface with dual-functional antibacterial effects for biomedical applications

Area of Science:

• Biomaterials Science
• Nanotechnology
• Infectious Diseases

Background:

• Implant-associated infections are a significant clinical challenge due to rising antibiotic resistance.
• Current treatments are limited by bacterial resistance, necessitating novel antibacterial strategies.
• Biomimetic surface topographies show promise but often lack efficacy against Gram-positive bacteria.

Purpose of the Study:

• To design and evaluate a novel substrate combining micro/nano-pillar arrays with titanium dioxide (TiO2).
• To investigate the topographical bacteriostatic effects of the pillar array independent of photocatalysis.
• To explore the potential synergistic antibacterial activity against antibiotic-resistant bacteria.

Main Methods:

• Fabrication of a novel model substrate featuring periodic micro/nano-pillar array and TiO2.
• Systematic investigation of the topographical effects on bacterial adhesion, growth, proliferation, and viability in the dark.
• Utilized Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) as model bacterial strains.

Main Results:

• The sub-micron pillar array significantly inhibited adhesion, growth, and proliferation of S. aureus and E. coli.
• Antibacterial effect attributed to spatial confinement and limited contact area provided by the topography.
• The topography alone was not lethal to bacteria within 24 hours, indicating a need for complementary mechanisms.

Conclusions:

• Periodic micro/nano-pillar arrays demonstrate significant bacteriostatic effects against common implant-associated pathogens.
• This topographical approach offers a non-antibiotic strategy for combating antibiotic resistance.
• Future work will explore the synergistic antibacterial activity of X-ray induced photocatalysis of TiO2 for enhanced efficacy.