Arsenic trioxide-based nanoparticles for enhanced chemotherapy by activating pyroptosis

Chemotherapy remains a primary treatment option for hepatocellular carcinoma (HCC), yet its clinical benefits are often unsatisfactory. Utilizing arsenic trioxide (ATO) as a model, this study elucidates the role of autophagy inhibition in modulating the cellular response to chemotherapy, shifting cell death from apoptosis to pyroptosis <i>via</i> the caspase-3-GSDME pathway, thereby augmenting the anti-tumor efficacy. Building upon these findings, an ATO nanomedicine delivery system capable of autophagy inhibition to promote pyroptosis for enhanced tumor treatment was developed. Folic acid-modified albumin served as the stabilizer for nano self-assemblies formed through ion pairing between Mn²⁺ and ATO, encapsulating DNAzyme (Dz) targeting Beclin 1, a key autophagy regulator. Characterization studies confirmed efficient encapsulation of ATO and Dz within nanoparticles, designed to disintegrate in the intracellular microenvironment, releasing the all-active components, <i>i.e.</i>, ATO, Mn²⁺, and Dz. Mn²⁺ acted as a metal cofactor to activate Dz for <i>Beclin</i> 1 mRNA cleavage, inhibiting autophagy and augmenting ATO-induced cell pyroptosis. Elevated cell pyroptosis levels not only enhance ATO's direct tumor cell killing capacity but also trigger anti-tumor immune responses, synergistically enhancing efficacy. Upon intravenous injection, the nanomedicine accumulated in tumor tissue and targeted liver cancer cells. Compared to free ATO, the nanomedicine exhibited significantly improved <i>in vivo</i> anti-tumor effects, achieving a 100% 45-day survival rate in mice with favorable biosafety profiles. This study offers novel insights into tumor chemotherapy sensitization and presents a promising strategy for ATO nanoformulation development.