In Vivo Biodistribution of Amino-Functionalized Ceria Nanoparticles in Rats Using Positron Emission Tomography

A variety of nanoparticles have been proposed for several biomedical applications. To gauge the therapeutic potential of these nanoparticles, in vivo biodistribution is essential and mandatory. In the present study, ceria nanoparticles (5 nm average particle size) were labeled with <sup>18</sup>F to study their in vivo biodistribution in rats by positron emission tomography (PET). The <sup>18</sup>F isotope was anchored by reaction of <i>N</i>-succinimidyl 4-[<sup>18</sup>F]­fluorobenzoate (<sup>18</sup>F-SFB) with a modified nanoparticle surface obtained by silylation with 3-aminopropylsilyl. Radiolabeled ceria nanoparticles accumulated mainly in lungs, spleen, and liver. Metabolic products of the radiolabeled nanoparticulate material were excreted into the urinary tract.