Bacterial Surface Appendages Modulate the Antimicrobial Activity Induced by Nanoflake Surfaces on Titanium

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Microbiology

Background:

• Bioinspired nanotopography offers a strategy for creating antimicrobial surfaces to prevent implant-associated infections.
• While 1D nanostructures have been explored, the antibacterial mechanisms of 2D nanostructures remain unclear.

Purpose of the Study:

• To investigate the antibacterial properties and mechanisms of 2D nanoflake surfaces on titanium (Ti).
• To understand the role of bacterial surface appendages in the interaction with these nanoflakes.

Main Methods:

• Hydrothermal synthesis was used to create 2D nanoflake surfaces on Ti substrates.
• The effects of these surfaces on Escherichia coli (E. coli) attachment, growth, and intracellular reactive oxygen species (ROS) were analyzed.
• Mutant strains of E. coli lacking type-1 fimbriae (ΔfimA) or flagella (ΔfliC) were used to assess the role of these appendages.

Main Results:

• The 2D nanoflake surfaces inhibited E. coli attachment and growth.
• Nanoflakes induced intracellular ROS accumulation in E. coli.
• Type-1 fimbriae offered protection to bacteria, while flagella increased susceptibility due to membrane abrasion.

Conclusions:

• 2D nanoflake surfaces exhibit antimicrobial activity against E. coli by impairing growth and inducing ROS.
• Bacterial surface structures, specifically type-1 fimbriae and flagella, play distinct roles in modulating bacterial interaction and susceptibility to nanoflake surfaces.
• These findings provide insights for designing effective antimicrobial surfaces for medical applications.