title: Investigation of sandwiched gadolinium (III) complexes with tungstosilicates as potential MRI contrast agents.
abstract: Two gadolinium-sandwiched complexes with tungstosilicates, K(13)[Gd(SiW(11)O(39))(2)] (Gd(SiW(11))(2)) and K(11)H(6)[Gd(3)O(3)(SiW(9)O(34))(2)] (Gd(3)(SiW(9))(2)), have been investigated by in vitro and in vivo experiments as potential contrast agents for magnetic resonance imaging (MRI). T(1)-relaxivity of Gd(SiW(11))(2)was 6.59 mM(-1).s(-1) in aqueous solution and 6.85 mM(-1).s(-1) in 0.725 mmol.L(-1) bovine serum albumin solution at 25 degrees C and 9.39 T, respectively. The corresponding T(1)-relaxivity of Gd(3)(SiW(9))(2) was 12.6 and 19.3 mM(-1).s(-1) per Gd, respectively. MRI for Sprague-Dawley rats showed longer and more remarkable enhancement in rat liver after i.v. injection of these two complexes: 39.4 +/- 3.9% and 57.4 +/- 11.6% within the first 30 min after injection, 31.2 +/- 2.6% and 39.9 +/- 7.6% in the next 60 min for Gd(SiW(11))(2) and Gd(3)(SiW(9))(2) at doses of 0.081 and 0.084 mmol Gd/kg, respectively. Our preliminary in vitro and in vivo study indicates that Gd(SiW(11))(2) and Gd(3)(SiW(9))(2) are favorable candidates for hepatic contrast agents for MRI. However, the two complexes exhibit higher acute toxicity and need to be modified and studied further before clinical use.
authors.affiliation: Laboratory of New Drug Research, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors.forename: Guoying
authors.initials: G
authors.lastname: Sun
authors.forename: Jianghua
authors.initials: J
authors.lastname: Feng
authors.forename: Huifeng
authors.initials: H
authors.lastname: Wu
authors.forename: Fengkui
authors.initials: F
authors.lastname: Pei
authors.forename: Ke
authors.initials: K
authors.lastname: Fang
authors.forename: Hao
authors.initials: H
authors.lastname: Lei
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000633:toxicity; D005682:Gadolinium / Q000633:toxicity; D007089:Image Enhancement / Q000379:methods; D007668:Kidney / Q000033:anatomy & histology; D007928:Lethal Dose 50; D008099:Liver / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017640:Silicates / Q000633:toxicity; D023382:Toxicity Tests, Acute; D017973:Tungsten Compounds / Q000633:toxicity
chemical_list: D003287:Contrast Media; D017640:Silicates; D017973:Tungsten Compounds; D005682:Gadolinium