Sonodynamic interfacial-assisted photosensitizer disrupts lipid bilayer order to eradicate gram-negative bacteria using HB@ZIF-8 nanoparticles

Here, we report a general ultrasound-assisted photodynamic strategy that overcomes this challenge by employing hypocrellin B (HB), originally a narrow-spectrum agent initially effective against Gram-positive bacteria, to eradicate Gram-negative bacteria. By applying exogenous ultrasound (US), we induce interfacial electron movement and leverage the cavitation effect to disrupt the lipid bilayer structure of the outer membrane (OM). Consequently, 200 μg mL −1 of HB@ZIF-8 (ZHB) achieves an almost 7-log reduction in Escherichia coli counts within 20 min, which is sixfold higher compared to the antibacterial activity exhibited by HB alone. Molecular dynamics simulations combined with 1.3-fold increase in fluorescence signals in OM permeability experiments confirm that the synergy of ultrasound and photodynamic treatment promotes OM permeability, facilitating rapid diffusion of ROS and HB into inner membrane and intracellular regions. Furthermore, the ZHB exhibited superior inhibition of bacterial proliferation, remarkably extending Shine Muscat grapes shelf life by up to 15 days. Therefore, the sonodynamic interfacial-assisted photosensitizer ZHB prepared in this work was found effective in enhancing the antimicrobial effect against foodborne pathogens.