Mitocytosis-inducing nanoparticles alleviate gemcitabine resistance via dual disruption of pyrimidine synthesis and redox homeostasis in pancreatic ductal adenocarcinoma

Metabolic reprogramming in pancreatic ductal adenocarcinoma (PDAC) poses a significant challenge to the efficacy of gemcitabine-based chemotherapy. Aberrant activation of intracellular pyrimidine metabolism is a key factor contributing to the reduced effectiveness of gemcitabine. Combining gemcitabine with metabolic regulators targeting critical pathways may alleviate gemcitabine resistance. In this study, we focus on the abnormal activation of dihydroorotate dehydrogenase (DHODH) in PDAC cells, a pivotal enzyme in the de novo pyrimidine synthesis pathway that diminishes cellular sensitivity to gemcitabine and catalyzes the reduction of ubiquinone to ubiquinol, playing an essential role in maintaining cellular redox homeostasis. To address these challenges, we developed GE11 peptide-modified polyphenol-iron chelate nanoparticles for co-delivery the long carbon chain-modified gemcitabine and the DHODH inhibitor leflunomide, with peptide modification enabling nanoparticles to target PDAC cells with high expression of epidermal growth factor receptor. The nanoparticles demonstrated the ability to induce mitocytosis and achieve deep tumor penetration in PDAC tissues. Upon drug release at the core lesion, the three components, modified gemcitabine, leflunomide and iron ions synergistically enhanced tumor cell killing by alleviating gemcitabine resistance and disrupting cellular redox homeostasis to induce multimodal cell death. In an in situ pancreatic cancer mouse model, this strategy exhibited superior anti-tumor efficacy compared to the standard AG chemotherapy regimen (nab-paclitaxel and gemcitabine), even at a 6.3-fold lower gemcitabine concentration. These findings underscore the potential of this approach as a highly effective therapeutic strategy for PDAC treatment.