Planar AIEgens with Enhanced Solid‐State Luminescence and ROS Generation for Multidrug‐Resistant Bacteria Treatment

Abstract

Planar luminogens have encountered difficulties in overcoming intrinsic aggregation‐caused emission quenching by intermolecular π‐π stacking interactions. Although excited‐state double‐bond reorganization (ESDBR) can guide us on designing planar aggregation‐induced emission (AIE) luminogens (AIEgens), its mechanism has yet been elucidated. Major challenges in the field include methods to efficiently restrict ESDBR and enhance AIE performance without using bulky substituents (e.g., tetraphenylethylene and triphenylamine). In this study, we rationally developed fluoro‐substituent AIEgens with stronger intermolecular H‐bonding interaction for restricted molecular motions and increased crystal density, leading to decreased nonradiative decay rate by one order of magnitude. The adjusted ESDBR properties also show a corresponding response to variation in viscosity. Furthermore, their aggregation‐induced reactive oxygen species (ROS) generations have been discovered. The application of such planar AIEgen in treating multidrug‐resistant bacteria has been demonstrated in a mouse model. The relationship between ROS generation and distinct E/Z‐configurational stacking behaviors have been further understood, providing a design principle for synthesizing planar AIEgen‐based photosensitizers.

Recent advances of AIE light-up probes for photodynamic therapy

“…With these strategies, various AIEgens with improved absorption, red-shied emission, and enhanced ROS production have been developed, and Table 1 summarizes the photophysical properties of these AIE photosensitizers, which await further engineering for real practical applications. [32][33][34][35] 2.2. Design concepts of AIE light-up probes 2.2.1 Aggregation-induced light-up.…”

A photo-sensitizable phage for multidrug-resistant Acinetobacter baumannii therapy and biofilm ablation

“…[12][13][14] In contrast, organic small molecules have high biosafety owing to easy metabolism in vivo, and they hold great promise in PACT. [15][16][17] However, many of the small molecular photosensitizers (PSs) used in PACT suffer from poor sensitivity due to inefficient generation of ROS and poor selectivity due to the lack of bacterial targeting ability. Thus the aim of this article is to develop a novel PACT agent that possess high selectivity and sensitivity to ght against MRAB and their biolms.…”

Acceptor Engineering for Optimized ROS Generation Facilitates Reprogramming Macrophages to M1 Phenotype in Photodynamic Immunotherapy

“…[5] In addition, it is well-known that there are two major types of PDT mechanisms triggered by the photosensitizers to produce various ROS: type Im echanism generating free radicals and type II mechanism generating singlet oxygen. [6] However,the relationship between the ROS generating signatures (e.g., efficiency and type) and the corresponding activating efficacyo fi mmune response for anti-tumor has been ambiguous and rarely explored. [7] For instance,itremains unclear what is the role of ROSgenerated from different mechanisms in repolarizing TAMs,a nd the effect of extracellular ROS and intracellular ROSo nt his process.T herefore,weanticipate that abetter understanding of the underneath mechanism in PDT immunotherapy will provide more insights into the rational design of specific photosensitizers for more effective cancer treatment.…”