AIE-based ruthenium complexes as photosensitizers for specifically photo-inactivate gram-positive bacteria.

The emergence of multidrug-resistant bacterial have caused severe burden for public health. Particularly, Staphylococcus aureus as one of ESKAPE pathogens have induced various infectious diseases and resulted in increasing deaths. Developing new antibacterial agents is still urgent and challenging. Fortunately, in this study, based on aggregation-induced emission (AIE) ruthenium complexes were designed and synthesized, which realized the high efficiency of reactive oxygen species generation and remarkably killed S. aureus unlike conventional antibiotics action. Significantly, owing to good singlet oxygen production ability, Ru1 at only 4 μg/mL of concentration displayed good antibacterial photodynamic therapy effect upon white light irradiation and could deplete essential coenzyme NADH to disrupt intracellular redox balance. Also, the electrostatic interaction between Ru1 and bacteria enhanced the possibility of antibacterial. Under light irradiation, Ru1 could efficiently inhibit the biofilm growth and avoid the development of drug-resistant. Furthermore, Ru1 possessed excellent biocompatibility and displayed remarkable therapy effect in treating mice-wound infections in vivo. These findings indicated that AIE-based ruthenium complexes as new antibacterial agent had great potential in photodynamic therapy of bacteria and addressing the drug-resistance crisis.