A Size-Adaptive Nanomicrobicide for Synergistic Photothermal and Gaseous Dismantling of Multidrug-Resistant Biofilms

Biofilms significantly impede the efficacy of conventional antimicrobial agents, particularly in multidrug-resistant (MDR) infections. In this work, we developed a size-adaptive, bismuth-based nanomicrobicide encapsulated with neutrophil membranes (Bi₂S₃/SNP@CM), designed to selectively generate nitric oxide (NO) within acidic biofilms under near-infrared (NIR) irradiation. The nanomicrobicide's adaptive size ensures deeper biofilm penetration and accumulation, while the neutrophil membrane coating enhances biocompatibility and targeting at infection sites. Upon NIR irradiation, localized heating and NO release synergistically eradicate MDR biofilms. Furthermore, the interactions between the nanomicrobicide and glutathione, as well as the reactions between NO and ROS, disrupt the intracellular redox balance, further amplifying the antibacterial efficacy. This innovative design affords a promising nanomicrobicide for effectively treating MDR biofilm infections.