title: A novel polyacrylamide magnetic nanoparticle contrast agent for molecular imaging using MRI.
abstract: A novel polyacrylamide superparamagnetic iron oxide nanoparticle platform is described which has been synthetically prepared such that multiple crystals of iron oxide are encapsulated within a single polyacrylamide matrix (PolyAcrylamide Magnetic [PAM] nanoparticles). This formulation provides for an extremely large T2 and T2* relaxivity of between 620 and 1140 sec(-1) mM(-1). Administration of PAM nanoparticles into rats bearing orthotopic 9L gliomas allowed quantitative pharmacokinetic analysis of the uptake of nanoparticles in the vasculature, brain, and glioma. Addition of polyethylene glycol of varying sizes (0.6, 2, and 10 kDa) to the surface of the PAM nanoparticles resulted in an increase in plasma half-life and affected tumor uptake and retention of the nanoparticles as quantified by changes in tissue contrast using MRI. The flexible formulation of these nanoparticles suggests that future modifications could be accomplished allowing for their use as a targeted molecular imaging contrast agent and/or therapeutic platform for multiple indications.
authors.affiliation: University of Michigan, Ann Arbor, USA.
authors.forename: Bradford A
authors.initials: BA
authors.lastname: Moffat
authors.forename: G Ramachandra
authors.initials: GR
authors.lastname: Reddy
authors.forename: Patrick
authors.initials: P
authors.lastname: McConville
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Hall
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Chenevert
authors.forename: Raoul R
authors.initials: RR
authors.lastname: Kopelman
authors.forename: Martin
authors.initials: M
authors.lastname: Philbert
authors.forename: Ralph
authors.initials: R
authors.lastname: Weissleder
authors.forename: Alnawaz
authors.initials: A
authors.lastname: Rehemtulla
authors.forename: Brian D
authors.initials: BD
authors.lastname: Ross
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000818:Animals; D001932:Brain Neoplasms / Q000175:diagnosis; D003287:Contrast Media / Q000737:chemistry / Q000493:pharmacokinetics; D006207:Half-Life; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011092:Polyethylene Glycols; D051381:Rats; D011916:Rats, Inbred F344; D014407:Tumor Cells, Cultured; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D003287:Contrast Media; D011092:Polyethylene Glycols; D000099166:Polyacrylamides