Investigation of sandwiched gadolinium (III) complexes with tungstosilicates as potential MRI contrast agents

✍ Scribed by Guoying Sun; Jianghua Feng; Huifeng Wu; Fengkui Pei; Ke Fang; Hao Lei

• Book ID: 103840101
• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 245 KB
• Volume: 22
• Category: Article
• ISSN: 0730-725X
• DOI: 10.1016/j.mri.2004.01.014

✦ Synopsis

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 Ϫ1 • s Ϫ1 in aqueous solution and 6.85 mM Ϫ1 • s Ϫ1 in 0.725 mmol • L Ϫ1 bovine serum albumin solution at 25°C and 9.39 T, respectively. The corresponding T 1 -relaxivity of Gd 3 (SiW 9 ) 2 was 12.6 and 19.3 mM Ϫ1 • s Ϫ1 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 Ϯ 3.9% and 57.4 Ϯ 11.6% within the first 30 min after injection, 31.2 Ϯ 2.6% and 39.9 Ϯ 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.