Inhalable biomimetic polyunsaturated fatty acid-based nanoreactors for peroxynitrite-augmented ferroptosis potentiate radiotherapy in lung cancer.

The limited efficacy and poor tumor accumulation remain crucial challenges for radiotherapy against lung cancer. To address these limitations, we rationally developed a polyunsaturated fatty acid (PUFA)-based nanoreactor (DHA-N@M) camouflaged with macrophage cell membrane to improve tumoral distribution and achieve peroxynitrite-augment ferroptosis for enhanced radiotherapy against lung cancer. After nebulization, the nanoreactors exhibited superior pulmonary accumulation in orthotopic lung cancer-bearing mice, with 70-fold higher than intravenously injected nanoreactors at 12 h post-administration, and distributed deeply in the tumors. DHA-N@M selectively released nitric oxide (NO) in glutathione (GSH)-enriched tumor cells, with consumption of GSH and subsequent inactivation of glutathione peroxidase 4 (GPX4). Under radiation, NO reacted with radiotherapy-induced reactive oxygen species (ROS) to generate peroxynitrite (ONOO-), resulting in redox homeostasis disruption. Combined with docosahexaenoic acid (DHA)-induced lipid metabolism disruption, overwhelming ferroptosis was induced both in vitro and in vivo. Notably, DHA-N@M mediated ferroptosis-radiotherapy significantly suppressed tumor growth with a 93.91% inhibition in orthotopic lung cancer models. Therefore, this design provides a nebulized ferroptosis-radiotherapy strategy for lung cancer.