Molecular Design and Biomedical Application of AIEgens with Photochemical Activity

Abstract

Photochemical reaction is expected to become a promising type of green chemistry with merits of operational flexibility, excellent regioselectivity, high yield, and mild reaction condition. Recently, aggregation-induced emission (AIE)-based fluorescent molecules with photoresponsivity have been quickly developed and employed in the biomedical field. In this Review, photoresponsive AIE materials based on the inherent photochemical reactions are highlighted according to the photochemical pathways: photoisomerization, photocyclization, photodimerization, and multiple photoreactions. Following this, their biomedical applications are summarized and discussed, including photoactivatable bioimaging, diagnosis, and therapy. Finally, the challenges and future perspectives are presented.

A Fast and Reversible Responsive Bionic Transmembrane Nanochannel for Dynamic Single-Cell Quantification of Glutathione

“…Upon experimental optimizations including a SiRh concentration of 1 mM (Figure S9) and incubation time of 2 h (Figure S10), the condensation reaction of SiRh with amine groups decreased the intensity of positive charges and thus weakened the ICR (blue curve). Considering the increase in contact angle experiments (from 53.8 ± 1.5° to 65.7 ± 1.8°) before and after SiRh modification (Figure S11), the increased surface hydrophobicity might be the reason for the reduced of surface charge. − In addition, the strong fluorescence of SiRh within the nanotip confirmed its successful modification (Figure c). The changes in the surface charge with each step of the modification were also verified by zeta potential measurements on the simulated surface of silica nanoparticles with the same treatment (Figure S12).…”

“…Stimuli-responsive small molecule probes endowed with structural diversity, high selectivity, sensitivity and good responsibility have shown promise for molecular recognition, biosensing and imaging. − Taking the purpose of precise quantification, they have also been synergized with the nanochannels to eliminate the probe diffusion during measurements. For instance, Li et al presented an NO gating system in a nanochannel of a polyethylene terephthalate membrane based on a spiro ring opening-closing reaction between o -phenylenediamine and NO, allowing for ionic NO biosensing .…”

Photoactivatable aggregation‐induced emission luminogens based on photodehydrogenation reactions for biomedical applications

“…In addition, they usually suffer from some shortcomings such as poor targeting ability of cancer cells, low treatment efficiency, strong side effects, and so forth [47]. Unlike traditional chemotherapy drugs, photoactivatable chemotherapeutic prodrugs can be controlled ease in vivo before photoactivation, or unclear photoactivation mechanism in the solid state [8,58]. More research in the future should be devoted to the development of novel AIE probes that can undergo photodehydrogenation reactions under near-infrared (NIR) light irradiation.…”

Bright and White Light-Triggered Aggregation-Induced Emission Nanoparticles Prepared in Miniemulsions for Photodynamic Theranostics

“…16,17 This involves improving the photophysical properties of AIE PSs, enhancing their stability and biocompatibility within biological systems, and optimizing their responsiveness to specific biomarkers. 18,19 By introducing specific functional groups or constructing complex molecular architectures, researchers have successfully developed AIE PSs with higher ROS generation efficiency, better targeting capabilities, and lower toxicity. 7,20−22 For instance, Wang et al 18 focused on the in situ synthesis of an AIE PS within cancer cells that specifically targets mitochondria, enabling precise and targeted PDT.…”

“…Much effort has been dedicated to enhance the performance of AIE PSs through molecular design and synthesis strategy. , This involves improving the photophysical properties of AIE PSs, enhancing their stability and biocompatibility within biological systems, and optimizing their responsiveness to specific biomarkers. , By introducing specific functional groups or constructing complex molecular architectures, researchers have successfully developed AIE PSs with higher ROS generation efficiency, better targeting capabilities, and lower toxicity. ,− For instance, Wang et al focused on the in situ synthesis of an AIE PS within cancer cells that specifically targets mitochondria, enabling precise and targeted PDT. This approach leverages the unique property of AIE materials to enhance the selectivity and efficiency of cancer cell ablation, minimizing the impact on surrounding healthy tissues .…”