Aggregation-induced Emission Probe for Fluorescence/Photoacoustic Dual-modality Imaging and Photodynamic/Photothermal Treatment

The combination of near-infrared (NIR) fluorescence imaging (FLI) and photoacoustic imaging (PAI) can effectively compensate for each other's inherent limitations, which can provide reliable and rich information on tumor biology. Therefore, the development of FL/PA dual-modality imaging probes is beneficial for achieving precision cancer diagnosis and treatment. Herein, we designed an efficient phototherapy agent methoxy bithiophene indene (OTIC), which was based on aggregation-induced emission (AIE) active fluorophores. To improve the water dispersion and enrichment of OTIC at the tumor site, OTIC nanoparticles (OTIC NPs) were prepared by a nanoprecipitation method. The balance between radiation and non-radiation energy dissipation was regulated by the strong donor-acceptor interaction and intramolecular motion. So OTIC NPs exhibited bright NIR fluorescence, photoacoustic signals, efficient generation of reactive oxygen species, and high photothermal conversion efficiency under NIR irradiation. Accurate imaging of the tumor and mice sentinel lymph nodes (SLNs) with OTIC NPs was visualized by NIR FL/PA dual-modal imaging. With the comprehensive imaging information provided by OTIC NPs in vivo, tumors were ablated under laser irradiation, which greatly improved the therapeutic efficacy. OTIC NPs would be possible to realize the precise guidance of FL/PA imaging for tumor treatment in the future clinical application.