Membrane restructuring and ordering: Antimicrobial mechanism of Zn3Al-LDH nanosheets against Gram-negative bacteria

Abstract

Despite the promising potential of zinc-aluminum layered double hydroxides (Zn3Al-LDHs) for antimicrobial applications, the dynamic interactions between Zn3Al-LDH and bacterial membranes at the interface remain poorly elucidated. This study employs all-atom molecular dynamics simulations using hybrid CHARMM36/ClayFF force fields to systematically investigate how Zn3Al-LDH nanosheets modify Escherichia coli-mimetic membranes. Our results reveal a three-stage interaction process that induces structural reorganization and compaction of the lipid bilayer, manifesting as membrane thickening and a reduced area per lipid. We find that these changes arise from synergistic charge screening and molecular ordering, particularly when the nanosheets are aligned parallel to the membrane. Based on these findings, we propose a dual antimicrobial mechanism that combines mechanical membrane stiffening with oxidative stress induced by Zn2+ leaching. These insights provide a foundation for engineering LDH-based surfaces with enhanced antibacterial efficacy.