Near-Infrared AIE Probe for Cancer Cell Imaging and Therapeutic Applications

Near infrared (NIR) aggregation-induced emission (AIE)-based luminogens are emerging as powerful materials with significant potential in cancer diagnosis, imaging, and therapy applications. Of precise note are the rapidly progressing areas in the field encompassing deep-tissue imaging, resistance to photobleaching, and biomedicine. Unlike traditional aggregation-caused quenching (ACQ) fluorophores, AIE materials with NIR emissive features can revolutionize the broad transdisciplinary areas of biomedicine, therapy, and healing, making them highly effective for real-time monitoring and healthcare purposes. In this study, we have synthesized a (E)-2-(2-(4'-(2,2-diphenylvinyl)-[1,1'-biphenyl]-4-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium, named as 3T, and explored its antiproliferative potential on MCF-7 and MDA-MB-231 breast cancer cells. The 3T molecule exhibited strong near-infrared (NIR) emission ranging from 600 to 800 nm in a 99% water fraction (f_w). In silico target prediction and molecular docking identified potential target proteins and assessed their binding interactions and affinities. Further, in vitro studies demonstrated efficient cellular internalization and dose-dependent reduction in cell viability. The IC₅₀ values of 32.26 and 35.75 μM were observed in MCF-7 and MDA-MB-231 cells, respectively. The treatment of 3T generated 2.1- and 1.9-fold increases in reactive oxygen species (ROS) for MCF-7 and MDA-MB-231 cells, respectively, and induced a change in mitochondrial membrane potential, leading to apoptosis, as confirmed by flow cytometry studies. The treatment was also effective for tumor spheroids. Thus, NIR AIEgen 3T offered several distinct advantages such as strong antiproliferative ability, stability, and imaging, positioning it as a potential candidate for cancer therapeutic applications.