Superparamagnetic Iron Oxide–Erastin–Polyethylene Glycol Nanotherapeutic Platform: A Ferroptosis-Based Approach for the Integrated Diagnosis and Treatment of Nasopharyngeal Cancer

Erastin can induce ferroptosis in tumor cells as an effective small molecule inhibitor. However, its application is hampered by a lack of water solubility. This study investigated the effects of superparamagnetic iron oxide (SPIO)-erastin-polyethylene glycol (PEG) nanoparticles prepared by loading SPIO-PEG nanoparticles with erastin on ferroptosis. SPIO-erastin-PEG nanoparticles exhibited square and spherical shapes with good dispersibility. The zeta potential and hydrodynamic size of SPIO-erastin-PEG were measured as (-37.68 ± 2.706) mV and (45.75 ± 18.88) nm, respectively. On T₂-weighted imaging, the nanosystem showed significant contrast enhancement compared to no-enhancement magnetic resonance imaging (MRI). SPIO-erastin-PEG induced ferroptosis by increasing reactive oxygen species and iron content and promoting the accumulation of lipid peroxides and the degradation of glutathione peroxidase 4. Pharmacokinetic experiments revealed a half-life of 1.25 ± 0.05 h for the SPIO-erastin-PEG solution in circulation. Moreover, significant antitumorigenic effects of SPIO-erastin-PEG have been demonstrated in 5-8F cells and mouse-bearing tumors. These results indicated that the synthesized SPIO-erastin-PEG nanoplatform could induce ferroptosis effects in vitro and in vivo while exhibiting favorable physical characteristics. This approach may provide a new strategy for theranostic nanoplatform for nasopharyngeal cancer.