  Whole body biodistribution of 100 nanometer sized polymer micellar
nanoparticles (NPs) was determined following intranasal administration using
PET/CT imaging on a clinical scanner. Nanoparticles labeled with Zirconium 89
were administered intranasally or intravenously to Sprague Dawley rats followed
by serial ex vivo PET/CT imaging in a clinical scanner. At 30 minutes and 1
hour following intranasal delivery, the animals were sacrificed and placed in
the PET/CT scanner. Images were acquired and transferred to a workstation for
post-processing. 3D regions of interest were constructed. A different set of
animals were used for ex vivo verification. These animals were also
administered 100 nm polymer micellar NPs and sacrificed at 30 min and 1 hr
following intranasal or intravenous delivery via intra-cardiac perfusion.
Various organs, including brain, lungs, heart, liver, spleen, stomach and
intestines, were procured following exsanguination. A gamma counter determined
activity in each organ for comparison with corresponding PET/CT region of
interest activity measurements. The ex vivo measurements of activity were
consistent with the image-based value determinations. Use of a clinical PET/CT
scanner is a feasible means to determine the temporal and spatial distribution
of radiolabeled agents after intranasal and intravenous delivery. This work may
allow for quantitative in vivo testing of new radionanotheranostic agents.
