An imaging-guided self-amplifying photo-immunotherapeutic nanoparticle for STING pathway activation and enhanced cancer therapy

The stimulator of interferon genes (STING) pathway is a promising target in cancer immunotherapy. However, current nanomedicine strategies targeting the STING pathway often suffer from limited tumor specificity and insufficient immune activation. In this study, we developed a novel imaging-guided, self-amplifying photo-immunotherapeutic nanoparticle (SSCOL), comprising a liposome framework that encapsulates the phase-change material perfluoropentane (PFP), the photothermal agent superparamagnetic iron oxide (SPIO), and the STING agonist cGAMP. This nanoparticle exhibits excellent photoacoustic/ultrasound dual-modal imaging capability, enabling precise visualization of tumor tissue. CREKA enables specific binding to fibrin-fibronectin complexes in the tumor stroma, while NIR-induced photothermal effects of SPIO trigger coagulation, amplifying target formation and enhancing nanoparticle accumulation via a positive feedback mechanism. Under photothermal therapy, the phase transition of SSCOL enables the controlled and efficient release of the encapsulated cGAMP, which subsequently activates the STING pathway and triggers a pro-inflammatory cascade, enhances dendritic cell maturation and cytotoxic T lymphocyte activation, and elicits robust immune responses against both primary and metastatic tumors. Collectively, this multifunctional nanoparticle offers a promising strategy that integrates imaging, targeting, and photothermal-enhanced immune activation for STING-mediated cancer immunotherapy.