title: Paramagnetic water-soluble metallofullerenes having the highest relaxivity for MRI contrast agents.
abstract: Water-soluble gadolinium (Gd) endohedral metallofullerenes have been synthesized as polyhydroxyl forms (Gd@C(82)(OH)(n)(), Gd-fullerenols) and their paramagnetic properties were evaluated by in vivo as well as in vitro for the novel magnetic resonance imaging (MRI) contrast agents for next generation. The in vitro water proton relaxivity, R(1) (the effect on 1/T(1)), of Gd-fullerenols is significantly higher (20-folds) than that of the commercial MRI contrast agent, Magnevist (gadolinium-diethylenetriaminepentaacetic acid, Gd-DTPA) at 1.0 T close to the common field of clinical MRI. This unusually high proton relaxivity of Gd-fullerenols leads to the highest signal enhancement at extremely lower Gd concentration in MRI studies. The strong signal was confirmed in vivo MRI at lung, liver, spleen, and kidney of CDF1 mice after i.v. administration of Gd-fullerenols at a dose of 5 micromol Gd/kg, which was 1/20 of the typical clinical dose (100 micromol Gd/kg) of Gd-DTPA.
authors.affiliation: Basic Research Institute, Nihon Schering K.K., 6-64 Nishimiyahara 2-chome Yodogawa-ku, Osaka, 532-0004, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Mikawa
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.forename: M
authors.initials: M
authors.lastname: Okumura
authors.forename: M
authors.initials: M
authors.lastname: Narazaki
authors.forename: Y
authors.initials: Y
authors.lastname: Kanazawa
authors.forename: N
authors.initials: N
authors.lastname: Miwa
authors.forename: H
authors.initials: H
authors.lastname: Shinohara
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry / Q000493:pharmacokinetics; D003287:Contrast Media / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D005069:Evaluation Studies as Topic; D005260:Female; D037741:Fullerenes; D005682:Gadolinium / Q000737:chemistry / Q000493:pharmacokinetics; D019786:Gadolinium DTPA / Q000737:chemistry / Q000493:pharmacokinetics; D007089:Image Enhancement / Q000379:methods*; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008279:Magnetic Resonance Imaging; D051379:Mice; D019906:Nuclear Magnetic Resonance, Biomolecular; D009942:Organometallic Compounds / Q000737:chemistry; D019047:Phantoms, Imaging; D011522:Protons; D012995:Solubility; D013154:Spleen / Q000378:metabolism / Q000473:pathology; D014018:Tissue Distribution
chemical_list: D003287:Contrast Media; D037741:Fullerenes; D009942:Organometallic Compounds; D011522:Protons; C108127:fullerenol; D002244:Carbon; D005682:Gadolinium; D019786:Gadolinium DTPA