Precise Molecular Engineering of Type I Photosensitizers with Near‐Infrared Aggregation‐Induced Emission for Image‐Guided Photodynamic Killing of Multidrug‐Resistant Bacteria

Abstract

Abstract Multidrug resistance (MDR) bacteria pose a serious threat to human health. The development of alternative treatment modalities and therapeutic agents for treating MDR bacteria‐caused infections remains a global challenge. Herein, a series of near‐infrared (NIR) anion–π+ photosensitizers featuring aggregation‐induced emission (AIE‐PSs) are rationally designed and successfully developed for broad‐spectrum MDR bacteria eradication. Due to the strong intramolecular charge transfer (ICT) and enhanced highly efficient intersystem crossing (ISC), these electron‐rich anion–π+ AIE‐PSs show boosted type I reactive oxygen species (ROS) generation capability involving hydroxyl radicals and superoxide anion radicals, and up to 99% photodynamic killing efficacy is achieved for both Methicillin‐resistant Staphylococcus aureus (MRSA) and multidrug resistant Escherichia coli (MDR E. coli) under a low dose white light irradiation (16 mW cm−2). In vivo experiments confirm that one of these AIE‐PSs exhibit excellent therapeutic performance in curing MRSA or MDR E. coli‐infected wounds with negligible side‐effects. The study would thus provide useful guidance for the rational design of high‐performance type I AIE‐PSs to overcome antibiotic resistance.

Keywords

• aggregation‐induced emission
• multidrug resistance bacteria
• photodynamic therapy
• photosensitizers
• type I reactive oxygen species