21:T485,Bacterial infectious diseases, especially those caused by Gram-positive bacteria, have been seriously threatening human health. Preparation of a multifunctional system bearing both rapid bacterial differentiation and effective antibacterial effects is highly in demand, but remains a severe challenge. Herein, we rationally designed and successfully developed a sequence of aggregation-induced emission luminogens (AIEgens) with orderly enhanced D-A strength. Evaluation of structure-function relationships reveals that AIEgens having intrinsic positive charge and proper ClogP value are able to stain Gram-positive bacteria. Meanwhile, one of the presented AIEgens (TTPy) can generate reactive oxygen species (ROS) in extraordinarily high efficiency under white light irradiation due to the smaller singlet-triplet energy gap. Thanks to the NIR emission, excellent specificity to Gram-positive bacteria, and effective ROS generation efficiency, TTPy has been proved to perform well in selective photodynamic killing of Gram-positive bacteria in vitro, such as S. aureus and S. epidermidis, even in S. aureus-infected rat wounds.22:T535,The highly oxygen-dependent nature of photodynamic therapy (PDT) limits its therapeutic efficacy against hypoxic solid tumors in clinics, which is an urgent problem to be solved. Herein, we develop an oxygen-independent supramolecular photodynamic agent that produces hydroxyl radical (^•OH) by oxidizing water in the presence of intracellularly abundant pyruvic acid under oxygen-free conditions. A fluorene-substituted BODIPY was designed as the electron donor and coassembled with perylene diimide as the electron acceptor to form the quadruple hydrogen-bonded supramolecular photodynamic agent. Detailed mechanism studies reveal that intermolecular electron transfer and charge separation upon light irradiation result in an efficient generation of radical ion pairs. Under oxygen-free conditions, the cationic radicals directly oxidize water to generate highly cytotoxic ^•OH, and the anionic radicals transfer electrons to pyruvic acid, realizing the catalytic cycle. Thus, this photodynamic agent exhibited superb photocytotoxicity even under severe hypoxic environments and excellent in vivo antitumor efficacy on HeLa-bearing mouse models. This work provides a strategy for constructing oxygen-independent photodynamic agents, which opens up an avenue for effective PDT against hypoxic tumors.23:T558,Abstract The severe hypoxia in solid tumors and the vicious aggregation‐caused fluorescence quenching (ACQ) of conventional photosensitizers (PSs) have limited the application of fluorescence imaging‐guided photodynamic therapy (PDT), although this therapy has obvious advantages in terms of its precise spatial–temporal control and noninvasive character. PSs featuring type I reactive oxygen species (ROS) based on free radicals and novel aggregation‐induced emission (AIE) characteristics (AIE‐PSs) could offer valuable opportunities to resolve the above problems, but molecular engineering methods are rare in previous reports. Herein, a strategy is proposed for generating stronger intramolecular charge transfer in electron‐rich anion‐π + AIE‐active luminogens (AIEgens) to help suppress nonradiative internal conversion and to promote radiative and intersystem crossing to boost free radical generation. Systematic and detailed experimental and theoretical calculations prove the proposal herein: the electron‐donating abilities are enhanced in collaborative donors, and the AIE‐PSs exhibit higher performance in near‐infrared fluorescence imaging‐guided cancer PDT in vitro / vivo. This work serves as an important reference for the design of AIE‐active free radical generators to overcome the ACQ and tumor hypoxia challenges in PDT.24:T598,

	Year	Citations

Abstract

References