title: Organic radical contrast agents for magnetic resonance imaging.
abstract: We report a molecular design that provides an intravenously injectable organic radical contrast agent (ORCA) for which the molecular (1)H water relaxivity (r(1)) is ca. 5 mM(-1) s(-1). The ORCA is based on spirocyclohexyl nitroxide radicals and poly(ethylene glycol) chains conjugated to a fourth-generation polypropylenimine dendrimer scaffold. The metal-free ORCA has a long shelf life and provides selectively enhanced magnetic resonance imaging in mice for over 1 h.
authors.affiliation: Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Rajca
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Michael
authors.initials: M
authors.lastname: Boska
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Paletta
authors.forename: Arnon
authors.initials: A
authors.lastname: Olankitwanit
authors.forename: Michael A
authors.initials: MA
authors.lastname: Swanson
authors.forename: Deborah G
authors.initials: DG
authors.lastname: Mitchell
authors.forename: Sandra S
authors.initials: SS
authors.lastname: Eaton
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Eaton
authors.forename: Suchada
authors.initials: S
authors.lastname: Rajca
mesh_terms: D003287:Contrast Media; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009930:Organic Chemicals
chemical_list: D003287:Contrast Media; D009930:Organic Chemicals