A Dual-Functional Antibiofilm Nanoplatform Integrating Photothermal Bactericidal Activity with Ga3+-Mediated Iron Metabolism Interference.

Abstract

Bacterial biofilms severely compromise antibiotic efficacy and accelerate drug resistance. Herein, a dual-functional nanoplatform (Ga-PDA NPs) was constructed through the coordination-driven assembly of gallium ions (Ga3+) and polydopamine (PDA) for synergistic photothermal and metabolic antibiofilm therapy. The PDA matrix serves as both a high-efficiency photothermal agent and a pH-responsive ligand, facilitating Ga3+ release within the acidic biofilm microenvironment. Under near-infrared irradiation, Ga-PDA NPs generate heat to disrupt bacterial membranes and the extracellular matrix. Concurrently, the released Ga3+ functions as a "Trojan horse," penetrating bacterial cells to interfere with iron metabolism, thereby triggering lethal iron starvation and widespread metabolic dysfunction. In vitro experiments verified potent bactericidal activity against Pseudomonas aeruginosa and Staphylococcus aureus. Moreover, when incorporated into bacterial cellulose membranes, this composite system exhibited excellent biocompatibility and effectively promoted the healing of biofilm-infected wounds in mice. Overall, this dual-functional nanoplatform provides a promising therapeutic strategy for the management of biofilm-associated infections.