The development of bacterial resistance makes the treatment of biofilm-associated infections extremely challenging. Photodynamic therapy (PDT), as a new treatment method, has shown great potential in antibacterial treatment, especially for drug-resistant bacterial infections. In this work, a highly effective cationic AIE antibacterial agent (β-PM-PIO) was developed based on PIO derivatives, which achieved effective antibacterial and biofilm treatment. In addition, its photophysical properties, antibacterial mechanism and whether it can induce bacterial resistance were studied in depth. β-PM-PIO has unique AIE features and excellent singlet oxygen generation ability. Meanwhile, the introduction of hydrophilic pyridine cations can not only improve the permeability of β-PM-PIO to biofilms, but also give it the function of targeting gram-positive bacteria. In addition to the fluorescence visualization of Gram-positive bacteria and the biofilm formed by them, β-PM-PIO can also show excellent antibacterial and anti-biofilm performance against Gram-positive bacteria under the synergistic effect of phototoxicity and dark toxicity, and hardly induce bacterial resistance in the treatment process. It is noteworthy that β-PM-PIO also has excellent resistance to methicillin-resistant Staphylococcus aureus (MRSA) in vivo.
Ph. D. candidate Jianqing Li in our group and Ph. D. candidate Zijuan Meng in China University of Geosciences (Wuhan) are the first authors of this article, and this work has been published in Small (DOI: 10.1002/ SMll.202200743).