Iron oxide nanoparticles as agents for combined therapy and magnetic resonance imaging

Multifunctional iron-oxide based nanoparticles for magnetic fluid hyperthermia (MFH-therapy) and magnetic resonance imaging (MRI-diagnostics) have been investigated for their morpho-dimensional characteristics and relaxometric properties. The nanoparticles were constituted of a spherical Fe3O4 core with diameter d = 19.2 +/- 3.6 nm, coated with meso-2,3-dimercaptosuccinic acid (DMSA). The 1H NMR results showed a longitudinal r1 relaxivity curve typical of high-anisotropy materials and a transverse relaxivity that, at clinical field mu 0H = 1.5 tesla, was similar to 3 times higher than the one of commercial MRI contrast agents. The system displayed a SAR similar to 110 +/- 30 W/gFe3O4 , i.e., high enough to allow for a successful combination of MFH-assisted-hyperthermia and hadron therapy on pancreatic tumor cells.