Co-delivery of polyphyllin II and IR780 PLGA nanoparticles induced pyroptosis combined with photothermal to enhance hepatocellular carcinoma immunotherapy.

The clinical efficacy of immunotherapy for hepatocellular carcinoma (HCC) is significantly limited by the low immunogenicity of the tumor. Recent studies have revealed that both pyroptosis and photothermal therapy can effectively induce tumor immunogenic cell death (ICD) in liver cancer cells. Polyphyllin II (PPII), the major active component of Rhizoma Paridis, has been demonstrated for the first time to induce pyroptosis in tumor cells, while IR780 is activated by 808 nm laser to transform light energy into heat energy, effectively eliminating tumor cells. However, both PPII and IR780 are afflicted with challenges such as low solubility and poor targeting, significantly limiting their utilization. To address these problems, the pyroptosis inducer PPII and photosensitizer IR780 were co-loaded in PLGA nanoparticles by precipitation method, and the aptamer AS1411 was modified on the surface of nanoparticles to construct the targeting nanoparticles (Apt/PPII/IR780-NPs). The nanoparticles exhibit a pH/NIR dual-response intelligent release feature, which realizes the targeted and controlled release of drugs in tumor site. Furthermore, it can rapidly release PPII to induce cell pyroptosis under laser irradiation, combining with IR780-based photothermal therapy exert a significant synergistic anti-tumor effect in vitro and in vivo. This process not only promotes maturation of DCs and activates effector T cells, thereby initiating adaptive immunity, but also generates enduring and effective immune memory. In addition, Apt/PPII/IR780-NPs significantly improved the Anti-PD-1 efficacy. In summary, chemo-photothermal therapy based on Apt/PPII/IR780-NPs can significantly enhance tumor ICD, which provides a promising new strategy for HCC immunotherapy.