Nanoparticle Biokinetics in Mice and Nonhuman Primates.

Despite the preponderance of iron oxide nanoparticles (NPs) designed for theranostic applications, widespread clinical translation of these NPs lags behind. A better understanding of how NP pharmacokinetics vary between small and large animal models is needed to rapidly customize NPs for optimal performance in humans. Here we use noninvasive magnetic resonance imaging (MRI) to track iron oxide NPs through a large number of organ systems in vivo to investigate NP biokinetics in both mice and nonhuman primates. We demonstrate that pharmacokinetics are similar between mice and macaques in the blood, liver, spleen, and muscle, but differ in the kidneys, brain, and bone marrow. Our study also demonstrates that full-body MRI is practical, rapid, and cost-effective for tracking NPs noninvasively with high spatiotemporal resolution. Our techniques using a nonhuman primate model may provide a platform for testing a range of NP formulations.