Fig. 1

The synthesis of SPION1-4 and MSPION1-4 with physical characterization. a, Schematic illustration of the synthesis process of MSPION. b, c, TEM images of the SPION1-4 nanoparticles prepared in 30 mL mixed solvents of diglycol/ethylene glycol with the volume ratio of 0, 0.23, 0.61, or 1.33 (b), or the MSPION1-4 nanoparticles prepared at 250 ^oC for 0.1 h, 12 h, 72 h, or 120 h based on SPION3 (c). d, e, SEM (d) and TEM (e) images of MSPION3 nanoparticles. f-i, Fe and O Elemental mapping (f), XRD spectrum (g), magnetization curve (h), and high-resolution XPS spectra of Fe2p (i) for MSPION3 without any surface coating or drug loading