Molecular Engineering of NIR-II/IIb Emitting AIEgen for Multimodal Imaging-Guided Photo-Immunotherapy.

In view of the great challenges related to the complexity and heterogeneity of tumors, efficient combination therapy is an ideal strategy for eliminating primary tumors and inhibiting distant tumors. A novel aggregation-induced emission (AIE) phototherapeutic agent called T-TBBTD is developed, which features a donor-acceptor-donor (D-A-D) structure, enhanced twisted molecule conformation, and prolonged second near-infrared window (NIR-II) emission. The multimodal imaging function of the molecule has significance for its treatment time window and excellent photothermal/photodynamic performance for multimode therapy. The precise molecular structure and versatility provide prospects for molecular therapy for anti-tumor applications. Fluorescence imaging in the NIR-II window offers advantages with enhanced spatial resolution, temporal resolution, and penetration depth. The prepared AIE@R837 NPs also have controllable performance for antitumor photo-immunotherapy. Following local photo-irradiation, AIE@R837 NPs generate abundant heat, and 1 O2 directly kills tumor cells, induces immunogenic cell death (ICD) as a photo-therapeutic effect, and releases R837, which enhances the synergistic effect of antigen presentation and contributes to the long-lasting protective antitumor immunity. A bilateral 4T1 tumor model revealed that this photo-immunotherapy can eliminate primary tumors. More importantly, it has a significant inhibitory effect on distant tumor growth. Therefore, this method can provide a new strategy for tumor therapy.