Necropotosis-Induciable Nanoliposomes for Enhanced Cancer Sonoimmunotherapy in Vitro

Background: Necroptosis has emerged as a therapeutic target for stimulating antitumor immune responses in dying tumor cells. However, its suppressed expression of receptor-interacting protein kinase 3 (RIPK3), a key enzyme in necrosis in most cancer cells, limits the clinical translation to exploiting necroptosis. Design: We fabricated a multifunctional phase-transition nanoparticles platform by constructing Lip-ICG-PFP-cRGD, utilizing liposome and indocyanine green (ICG) as the shell and perfluoropentane (PFP) as the core. The platform system represented the combination of sonodynamic therapy (SDT) and immunotherapy for cancer treatment by inducing necroptosis and disrupting the cell membrane through the acoustic cavitation effect mediated by ultrasound. In addition to their inherent contrasting ability under photoacoustic imaging, our liposomes may also be used as an ultrasound imaging probe after being irradiated with low-intensity focused ultrasound (LIFU). Results: : We demonstrate that nanoparticles can trigger necroptosis in ovarian cancer cells, which ruptures cell membrane by acoustic cavitation effect. When exposed to LIFU, the nanoparticles effectively facilitate the release of damage-associated molecular patterns by inducing burst-mediated cell-membrane decomposition. Moreover, the PFP phase change caused RIPK3/MLKL-independent necroptosis by acoustic cavitation effect, resulting in the release of biologically active DAMPs (CRT and HMGB1) to facilitate antitumor immunity. Therefore, necroptosis-inducible nanoparticles remarkably enhance antitumor immunity by activating CD8 + cytotoxic T cells and maturing dendritic cells in vitro. Conclusion: We have successfully synthesized Lip-ICG-PFP-cRGD nanoparticles, which can achieve SDT and provoke necroptosis by bubble-mediated cell membrane rupture. The innovative nanoparticle causes immunogenic cell death in cancer cells via RIPK3-independent necroptosis, which is a promising enhancer for cancer immunotherapy.