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 via 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.e., ATO, Mn²⁺, and Dz. Mn²⁺ acted as a metal cofactor to activate Dz for Beclin 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 in vivo 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.