Gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid conjugate of arabinogalactan as a potential liver-targeting magnetic resonance imaging contrast agent

•AG-CM-EDA-DOTA-Gd was synthesized and characterized as the MRI contrast agent.•The T1-relaxivity of AG-CM-EDA-DOTA-Gd was 1.86 times than that of Gd-DOTA.•The imaging of the liver showed enhancement after injection of AG-CM-EDA-DOTA-Gd.•AG-CM-EDA-DOTA-Gd was a potential liver-specific contrast agent for MRI.

A novel biocompatible macromolecule (AG-CM-EDA-DOTA-Gd) was synthesized as a liver magnetic resonance imaging (MRI) contrast agent. AG-CM-EDA-DOTA-Gd consisted of a carboxymethyl-arabinogalactan unit conjugated with gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (Gd-DOTA) via ethylenediamine, and was specifically designed to bind to hepatocyte asialoglycoprotein in vivo, in an effort to develop a potential new tool for the diagnosis of liver diseases. The T1-relaxivity (8.87 mmol−1 L s−1) of AG-CM-EDA-DOTA-Gd was 1.86 times than that of Gd-DOTA (4.76 mmol−1 L s−1) in D2O at 9.4 T and 25 °C. MRI experiments showed significant enhancement in rat liver following the intravenous administration of AG-CM-EDA-DOTA-Gd (0.094 mmol Gd3+/kg body weight), which persisted for longer than Gd-DOTA (0.098 mmol Gd3+/kg body weight). The mean percentage enhancements in the liver parenchyma were 85.2 ± 6.5% and 19.3 ± 3.3% for AG-CM-EDA-DOTA-Gd and Gd-DOTA, respectively. The results of this study therefore indicate that AG-CM-EDA-DOTA-Gd could be used as a potential liver-targeting contrast agent for MRI.

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