In contrast to monomers that are randomly distributed in solution or in an amorphous state, constructing a highly crystalline framework with precise molecular arrangement might provide materials with markedly enhanced functionalities. Herein, a large π-conjugated electron donor-acceptor (D-A) type molecule was designed and synthesized, which self-assembles through hydrogen bonds to form an organic framework named PFC-513. The ordered arrangement dramatically boosts the quantum yield (ΦΔ) of singlet oxygen generation, classified as type IIreactive oxygen species (ROS), from 0.01 for the monomer to 0.98 for PFC-513, while enabling the hydroxyl radical generation (type I ROS), which is absent in the monomeric state. Such dual-mode Type I/II Photosensitization grants PFC-513 potent antibacterial activity against methicillin-resistant bacteria and E. coli. Beyond direct antibacterial action, PFC-513 can simultaneously downregulate key pro-inflammatory cytokines and chemokines under light irradiation for a diabetic wound, therefore synergistically accelerating wound healing. This work establishes a new paradigm for engineering crystalline porous frameworks with superior PDT efficacy, offering a promising strategy for combating infections and promoting wound repair.
Cheng et al. (Fri,) studied this question.