Target-activated selective photodynamic antibacterial therapy: In situ enhancing 1O2 yield of conjugated polyelectrolytes by E. coli surface

Abstract

Photodynamic antimicrobial therapy has emerged as promising strategy to address the growing challenge of antibiotic resistance. However, its potential is often hindered by limited selectivity of photosensitizers and non-specific cytotoxicity during treatment. In this study, we present a novel mechanism utilizing positively charged conjugated polyelectrolytes (PFBT) for target-activated selective photodynamic antibacterial therapy. The negatively charged surface of Escherichia coli (E. coli) induces in situ modulation of the polymer's aggregation state, and triggers a 350% enhancement in PFBT's singlet oxygen generation, while negligible activation can be observed by mammalian cells. This selective activation enabled efficient photodynamic eradication of bacteria with minimal toxicity to mammalian cells, promoting rapid wound healing in infection scenarios. These findings pave the way for the development of in situ target-activated optical therapeutic strategies that prioritize specificity while minimizing collateral damage to healthy tissues.

Keywords: Optical property regulation; Photodynamic antibacterial; Target-activated.