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.