Light activated “spy” bacteria: Mediated PTT/PDT/Lysozyme hydrolysis for synergistic treatment of <i>MRSA</i> wound infections

<i>Methicillin-resistant Staphylococcus aureus</i> (<i>MRSA</i>) presents a significant challenge in wound infection treatment due to its antibiotic resistance and biofilm formation. To address this, we utilized <i>Escherichia coli</i> (Ec) as a carrier to deliver lysozyme (LYZ) and adsorb the photosensitizer indocyanine green (ICG), resulting in the Ec-LYZ-ICG multi-functional antimicrobial platform. Since both Ec and <i>MRSA</i> are bacteria, this platform can act as a “spy”, evading the immune surveillance of <i>MRSA</i> and effectively penetrating infection sites. Upon exposure to 808 nm laser irradiation, Ec-LYZ-ICG utilizes the synergistic effects of photothermal therapy (PTT) and photodynamic therapy (PDT) induced by ICG, which ruptures Ec membrane and releases LYZ. The combined PTT and PDT directly damage <i>MRSA</i>, while LYZ further hydrolyzes <i>MRSA</i>. This strategy, with its “spy-like” camouflage and penetration abilities, overcomes <i>MRSA</i>’s antibiotic resistance and immune evasion, providing new insights and approaches for the precise treatment of <i>MRSA</i> infections.