Hybrid Nanoplatform: Enabling a Precise Antitumor Strategy via Dual-Modal Imaging-Guided Photodynamic/Chemo-/Immunosynergistic Therapy

Photodynamic therapy (PDT) has been widely used in tumor therapy due to its high spatial-temporal control and noninvasiveness. However, its clinical application is limited by weak efficacy, shallow tissue penetration, and phototoxicity. Herein, a facile theranostic nanoplatform based on photoswitchable lanthanide-doped nanoparticles was designed. Typically, these nanoparticles had UV-blue and 1525 nm emission upon 980 nm excitation and 1525 nm emission upon 800 nm excitation. We further used these nanoparticles for achieving real-time near-infrared (NIR)-IIb imaging (800 nm) with a high signal-to-noise ratio and imaging-guided PDT (980 nm). Moreover, such a photoswitchable nanoplatform capping with pH-sensitive calcium phosphate for coloading doxorubicin (a chemotherapeutic immunogenic cell death [ICD] inducer) and paramagnetic Mn2+ ions enhances T-1-magnetic resonance imaging in the tumor microenvironment. Our results suggest that this theranostic nanoplatform could not only kill tumor cells directly through dual-modal image-guided PDT/chemotherapy but also inhibit distant tumor and lung metastasis through ICD. Therefore, it has great potential for clinical application.