AIEgens for Bacterial Imaging and Ablation

Abstract

Accurate and sensitive diagnosis of pathogenic bacterial infection is a fundamental first step for correct bacteria management, helping to avoid the development of drug-resistant bacteria caused by the inappropriate use and overuse of antibiotics. Fluorescence probes as a promising visual tool can help identify pathogens rapidly and reliably. However, rigidly structured traditional fluorescence probes generally suffer from the drawback of aggregation-caused quenching (ACQ) effect, which greatly undermines their advantages with respect to sensitivity. Luminogens with aggregation-induced emission properties, namely AIEgens, can overcome the ACQ effect and certain AIEgen-based materials are capable of generating reactive oxygen species (ROS) in the aggregate states. Hence, they have become powerful tools for imaging and killing bacteria. This review summarizes the recent advances in AIEgens for the diagnosis and treatment of pathogen infections. Special attention has been paid to the molecular design, the application in bacterial imaging and ablation in vitro and in vivo, and the biocompatibility of AIEgens. Finally, the challenges and prospects are discussed in terms of using AIEgens to advance precision therapies for pathogen infections.

Aggregation-Induced Emission Artificial Enzyme (AIEzyme) with DNase-Like Activity: Imaging and Matrix Cleavage for Combating Bacterial Biofilm

“…In contrast, many common AIEgens kill bacteria by photo-generated ROS, photothermal effect and their own toxicity. 26,[49][50][51] So, for general antibacterial methods based on AIEgens, the regular irradiation and dressing change are usually required. [52][53][54] As for the proposed anti-biofilm method based on AIEzymes (Figure 7a), the irradiation and the dressing change are not required, avoiding the frequent operations and the exogenous infection.…”

“…[19][20][21][22][23][24] So, AIEgens become a kind of ideal tools for imaging microorganisms, cancer cells and so on. [25][26][27] On the other hand, many AIEgens can also kill planktonic bacteria by photo-induced reactive oxygen species (ROS), photothermal effect and their own toxicity. [28][29] However, they are expert at killing planktonic bacteria rather than anti-biofilm, because biofilm is markedly more resistant to environment stresses including ROS, high temperature and antibacterial agents.…”

Aggregation‐Induced Emission Luminogens with Photoresponsive Behaviors for Biomedical Applications

“…As the bacterial surface is always negatively charged, various AIEgens with positive charge have been synthesized to exhibit light-up fluorescence upon binding with bacteria via strong electrostatic interactions, [28,77,79] some of these AIEgens, such as TGP, have been mentioned above. Upon connection with certain biomolecules as bacteria recognition groups, AIEgens further exhibit a higher selectivity for binding to bacteria.…”

Boosting the photodynamic therapy of near-infrared AIE-active photosensitizers by precise manipulation of the molecular structure and aggregate-state packing

“…35 As a noninvasive feature and controllability method, PDT treatment can overcome the side effects of traditional methods such as radiotherapy, chemotherapy, and surgical resection. [36][37][38] To achieve an efficient PDT process, photosensitizers (PSs) [39][40][41][42] with excellent reactive oxygen species (ROS) generation ability are highly desired. 43,44 In biologically relevant processes, however, the chemical structures, the physiological environments, [45][46][47] and the self-assembled forms [48][49][50] of PSs have a salient influence on the inherent properties including the ROS generation ability as well as the emission behaviors.…”