Programmed enhancement of endogenous iron-mediated lysosomal membrane permeabilization for tumor...

Ferroptosis and pyroptosis, as emerging regulated forms of cell death capable of overcoming apoptotic resistance, demonstrate promising potential in tumor therapy. Given that iron manipulation and reactive oxygen species elevation serve as common stimuli for both processes, inducing lysosomal membrane permeabilization (LMP) with ensuing release of lysosomal contents (including iron ions and cathepsins) is anticipated to realize dual induction of ferroptosis/pyroptosis. Herein, we report a folic acid and croconaine molecule-functionalized upconversion nanoparticle (UCNP-Cro/FA) that is able to mobilize intracellular stores of endogenous iron and spatiotemporally control the lysosome-intrinsic Fenton chemistry, thereby triggering LMP-associated cell death. The process of endogenous iron mobilization occurs through two key steps: Cro-mediated coordination of abundant Fe³⁺ ions within lysosomes, followed by UV-emitting upconversion core-mediated photoreduction, resulting in Fe²⁺ ions release. Both in vitro and in vivo experiments show that UCNP-Cro/FA + NIR treatment effectively boost LMP by endogenous iron-mediated •OH production, ultimately triggering irreversible tumor cell death via ferroptosis and Caspase-1/GSDMD-dependent pyroptosis pathways. Moreover, this process potentiates tumor immunogenicity, holding promise for tumor immunotherapy. Overall, this work proposes a feasible tumor therapy strategy that integrates ferroptosis and pyroptosis through the efficient application and activation of endogenous iron.