title: Integrity of (111)In-radiolabeled superparamagnetic iron oxide nanoparticles in the mouse.
abstract: BACKGROUND
  Iron-oxide nanoparticles can act as contrast agents in magnetic resonance imaging (MRI), while radiolabeling the same platform with nuclear medicine isotopes allows imaging with positron emission tomography (PET) or single-photon emission computed tomography (SPECT), modalities that offer better quantification. For successful translation of these multifunctional imaging platforms to clinical use, it is imperative to evaluate the degree to which the association between radioactive label and iron oxide core remains intact in vivo.
  
  
  METHODS
  We prepared iron oxide nanoparticles stabilized by oleic acid and phospholipids which were further radiolabeled with (59)Fe, (14)C-oleic acid, and (111)In.
  
  
  RESULTS
  Mouse biodistributions showed (111)In preferentially localized in reticuloendothelial organs, liver, spleen and bone. However, there were greater levels of (59)Fe than (111)In in liver and spleen, but lower levels of (14)C.
  
  
  CONCLUSIONS
  While there is some degree of dissociation between the (111)In labeled component of the nanoparticle and the iron oxide core, there is extensive dissociation of the oleic acid component.
authors.affiliation: Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115; Nanomedicine Science and Technology Center, Northeastern University, Boston, MA 02115.
authors.forename: Haotian
authors.initials: H
authors.lastname: Wang
authors.affiliation: Nanomedicine Science and Technology Center, Northeastern University, Boston, MA 02115.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Nanomedicine Science and Technology Center, Northeastern University, Boston, MA 02115.
authors.forename: Dattatri
authors.initials: D
authors.lastname: Nagesha
authors.affiliation: Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115.
authors.forename: Richard I
authors.initials: RI
authors.lastname: Duclos
authors.affiliation: Nanomedicine Science and Technology Center, Northeastern University, Boston, MA 02115.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Sridhar
authors.affiliation: Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115. Electronic address: s.gatley@neu.edu.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Gatley
mesh_terms: D000818:Animals; D002626:Chemistry, Pharmaceutical; D005290:Ferric Compounds / Q000737:chemistry* / Q000493:pharmacokinetics; D007205:Indium Radioisotopes; D007553:Isotope Labeling; D008024:Ligands; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008297:Male; D051379:Mice; D019301:Oleic Acid / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D049268:Positron-Emission Tomography; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005290:Ferric Compounds; D007205:Indium Radioisotopes; D008024:Ligands; D058185:Magnetite Nanoparticles; D010743:Phospholipids; C000499:ferric oxide; D019301:Oleic Acid; D011092:Polyethylene Glycols
keywords: Mouse; Radioactivity; SPION