Chemical Doping of Iron Oxide Inside Apoferritin to Form an MRI Contrast Agent with High R1 and Low R2

Maria Veronica Clavijo Jordan¹, Kevin M. Bennett¹

Chemical doping is implemented in order to disrupt magnetic moment coupling within a crystal and render a paramagnetic nanoparticle. Tunstate is introduced inside the apoferritin cavity as a dopant of the iron oxide core. The crystal surface un-coupled moments are in close contact with the surrounding water protons to reduce overall longitudinal relaxation. The paramagnetic apoferritin composite resulted in a particle r₁ of 4870mM^-1s^-1 and r₂/r₁ of 1.86 making them a sensitive nanoparticle agent for in vivo molecular MRI.