Abstract
We report on the Fe-59 radiolabelling of iron oxide nanoparticle cores through post-synthetic isotope exchange (Fe-59-IONPex) and precursor labelling (Fe-59-IONPpre). Scanning electron microscopy and dynamic light scattering measurements showed no impact of radiolabelling on nanoparticle size or morphology.
While incorporation efficiencies of these methods are comparable-83 and 90% for precursor labelling and post-synthetic isotope exchange, respectively-Fe-59-IONPpre exhibited much higher radiochemical stability in citrated human plasma. Quantitative ex vivo biodistribution study of Fe-59-IONPpre coated with triethylene glycol was performed in Wistar rats.
Following the intravenous administration, high Fe-59 concentration was observed in the lung and the organs of the reticuloendothelial system such as the liver, the spleen and the femur.