NIR AIE luminogens for primary and metastasis tumor imaging and tracking applications

Modern lifestyle changes, including irregular diets and late-night activities, have contributed to a significant rise in cancer rates, particularly among younger demographics, highlighting the pressing need for early detection and treatment. Fluorescence imaging techniques play a crucial role in tumor diagnosis, yet traditional organic fluorescent materials suffer from limitations such as poor photostability and fluorescence quenching in aggregates. This paper introduces the design and synthesis of four aggregation-induced emission (AIE) molecules with near-infrared I emission, which are aimed at overcoming fluorescence quenching in the molecular aggregation state. The photophysical properties of these molecules (BTA-TT, BTA-TTM, BTA-FT, and BTA-FTM) were investigated and they exhibited TICT and AIE behaviors in varying water fractions, along with notably large Stokes shifts. In vitro imaging of the four molecules successfully imaged lysosomes within 4T1 cells and they displayed minimal dark toxicity. Moreover, these AIEgens exhibited excellent anti-photobleaching properties, which were superior to those of commercial dyes. In addition, BTA-FTM nanoparticles coated with PEG-2000 showed biosafety and enabled tumor imaging in mice for 59 hours, revealing the tumor metastases in the heart and lungs of mice. This research contributes to the development of novel near-infrared molecules for advanced diagnostic applications.