Induction of Ferroptosis by an Amalgam of Extracellular Vesicles and Iron Oxide Nanoparticles Overcomes Cisplatin Resistance in Lung Cancer

Extracellular vesicles (EVs) hold potential as effective carriers for drug delivery, providing a promising approach to resolving challenges in lung cancer treatment. Traditional treatments, such as with the chemotherapy drug cisplatin, encounter resistance in standard cell death pathways like apoptosis, prompting the need to explore alternative approaches. This study investigates the potential of iron oxide nanoparticles (IONP) and EVs to induce ferroptosis--a regulated cell death mechanism--in lung cancer cells. We formulated a novel EV and IONP-based system, namely ExoFeR, and observed that ExoFeR demonstrated efficient ferroptosis induction, evidenced by downregulation of ferroptosis markers (xCT/SLC7A11 and GPX4), increased intracellular and mitochondrial ferrous iron levels, and morphological changes in mitochondria. To enhance efficacy, tumor-targeting transferrin (TF)-conjugated ExoFeR (ExoFeRTF) was developed. ExoFeRTF outperformed ExoFeR, exhibiting higher uptake and cell death in lung cancer cells. Mechanistically, nuclear factor erythroid 2-related factor 2 (Nrf2)--a key regulator of genes involved in glutathione biosynthesis, antioxidant responses, lipid metabolism, and iron metabolism--was found downregulated in the ferroptotic cells. Inhibition of Nrf2 intracellular translocation in ExoFeRTF-treated cells was also observed, emphasizing the role of Nrf2 in modulating ferroptosis-dependent cell death. Furthermore, ExoFeR and ExoFeRTF demonstrated the ability to sensitize chemo-resistant cancer cells, including cisplatin-resistant lung cancer patient-derived tumoroid organoids. In summary, ExoFeRTF presents a promising and multifaceted therapeutic approach for combating lung cancer by intrinsically inducing ferroptosis and sensitizing chemo-resistant cells.