177Lu Radiolabelled AIE Dots for Multimodal Imaging Guided Photothermal/Radiopharmaceutical Tumor Therapy

Abstract Aggregation‐induced emission luminogens (AIEgens) in the second near‐infrared region (NIR‐II,1000‐1700 nm) have shown tremendous potential as theragnostic probe for tumor multimodal diagnostic imaging and combined treatment owing to their programmable optical, structural and functional properties. Herein, we presented a radionuclide 177 Lu‐labeled AIEgen, 177 Lu‐2TT‐oC6B dots, for NIR‐II fluorescence and SPECT/CT imaging‐guided tumor photothermal and radiopharmaceutical therapy. Intriguingly, 177 Lu‐2TT‐oC6B self‐assembled into 10 nm dots, exhibited high NIR‐II fluorescence quantum yield (QY, 1.34 %) and unprecedented photothermal conversion efficiency (PCE, 70.3 %) in vitro , furtherly performed extremely long blood circulation (T 1/2 =52.4 h), persistent tumor accumulation and retention in tumor (NIR‐II SNR=5.56; SPECT SNR=36.59) via intravenous administration in vivo . Furthermore, upon NIR light activation and 177 Lu irradiation, 177 Lu‐2TT‐oC6B demonstrated great application potential in synergistic photothermal/radiopharmaceutical tumor therapy.