Antimony Component Schottky Nanoheterojunctions as Ultrasound-Heightened Pyroptosis Initiators for Sonocatalytic Immunotherapy.

ABSTRACT

Sonocatalytic therapy (SCT) holds promise due to its exceptional penetration depth; however, the rapid recombination of electron-hole (e--h+) pairs and the complex tumor microenvironment (TME) impede its broader application. Herein, we discovered that antimony (Sb)-based nanomaterials induced pyroptosis in cancer cells. Therefore, a Schottky heterojunction containing a Sb component (Sb2Se3@Pt) was effectively designed and constructed via in-situ growth of platinum (Pt) nanoparticles (NPs) on a Sb2Se3 semiconductor with narrow bandgaps, which were utilized as US-heightened pyroptosis initiators to induce highly effective pyroptosis in cancer cells to boost SCT-immunotherapy. The biological effects of the Sb2Se3@Pt nanoheterojunction itself combined with the sonocatalytic amplification of oxidative stress significantly induced Caspase-1/GSDMD-dependent pyroptosis in cancer cells. Therefore, SCT treatment with Sb2Se3@Pt not only effectively restrained tumor proliferation but also induced potent immune memory responses and suppressed tumor recurrence. Furthermore, the integration of this innovative strategy with immune checkpoint blockade (ICB) treatment elicited a systemic immune response, effectively augmenting therapeutic effects and impeding the growth of abscopal tumors. Overall, this study provides further opportunities to explore pyroptosis-mediated SCT-immunotherapy.