A synergistic strategy of AIE and electron asymmetry anchored in covalent organic frameworks for enhanced periodontitis photodynamic therapy.

Periodontitis, a widespread inflammatory disease, is difficult to treat effectively due to incomplete mechanical cleaning and increasing antibiotic resistance. To overcome this issue, we developed a new covalent organic framework, THP-PE-COF, which combines aggregation-induced emission (AIE) with local asymmetric electron distribution (LAED) to enhance photodynamic therapy (PDT). The AIE unit prolongs fluorescence lifetime and inhibits charge recombination, while the electron-donating triphenylthiophene (THP) induces LAED to form local dipoles that promote oxygen adsorption and charge separation. Compared with control THP-PB-COF and THP-BPE-COF, THP-PE-COF exhibited improved light absorption, charge dynamics, and reactive oxygen species (ROS) generation. It showed strong antibacterial activity against Porphyromonas gingivalis and Fusobacterium nucleatum in vitro and demonstrated effective periodontitis treatment with decreased inflammatory responses in vivo. This work pioneered the integration of AIE and LAED in COFs, providing a promising antibiotic-free strategy for periodontal therapy.