Spatiotemporal Blockade of Autophagy and Macropinocytosis in Pancreatic Cancer via Lysosomal-Activated Nanoreactors

Autophagy blockade has emerged as a promising strategy to enhance the antitumor efficacy of pancreatic ductal adenocarcinoma (PDAC). However, autophagy inhibition in PDAC may induce compensatory macropinocytosis to maintain cellular homeostasis by upregulating nuclear factor erythroid 2-related factor 2 (NRF2). In this study, lysosomal-activated nanoreactors loaded with the NRF2 inhibitor ML385 (CPZI-Ms) are developed to spatiotemporally block autophagy and inhibit macropinocytosis. The nanoreactors, which preferentially accumulate in lysosomes, undergo degradation in the acidic lysosomal environment, triggering a Fenton-like reaction between the released Cu 2 ⁺ ions and H₂O₂ to generate hydroxyl radicals. This results in lysosomal membrane permeabilization, which further leads to not only lysosomal autophagy blockade, but also the leakage of Cu 2 ⁺ and ML385 into the cytoplasm. Cu 2 ⁺ induces extensive oxidative stress throughout the whole cell, while ML385 suppresses compensatory macropinocytosis response activated by autophagy blocking. As a result, the Panc02 cells become a “besieged fortress”, with impaired autophagic clearance and restricted nutrient uptake. In vivo, CPZI-Ms effectively suppress tumor growth in Panc02-bearing mice, offering a promising nanoplatform for enhancing cancer cell killing. Taken together, the present work provides an innovative anti-tumor insight by spatiotemporally blocking autophagic flux and inhibiting compensatory macropinocytosis.