Regulation of nanotopography of ionic liquid gel particles through the introduction of a second network and its impact on antibacterial properties

The inherent antibacterial properties of micro/nanoparticles hold promise for addressing the growing challenge of bacterial resistance to antibiotics. Thus, developing new types of micro/nanoparticles is of great significance. Herein, we present a novel class of bigel particles, which are composed of 1-butyl-3-methylimidazolium hexafluorophosphate as the liquid dispersion medium, poly-methyl methacrylate as the polymer network of the seed gel, and poly-γ-methacryloxypropyltrimethoxysilane as the introduced secondary network. We demonstrate that the nanotopography of these bigels can be easily regulated by adjusting the pH, resulting in particles with the same composition but varying shapes and surface nanotopographies. Antibacterial testing reveals that the inherent antibacterial property of the bigel particles can be significantly enhanced by controlling their nanotopographies while showing no toxicity to mammalian cells. This work expands the range of materials available for antimicrobial micro/nanoparticles, introduces a method for controlling the nanotopography of ionic liquid gel particles, and demonstrates that the nanotopography of flexible organic micro/nanoparticles can influence their intrinsic antibacterial properties.