Weiyuan Xu, Xinhui Xiao, Zheng Cai, Jiao Xu, Weihao Yan, T. Yang, Mei Huang, Peijie Guan, Xiaoying Wu, Yong Jian, Yunkai Wang, Fangfu Ye, Zhihan Yan, Lixiong Dai
Abstract Gadolinium (Gd3+) based contrast agents (GBCAs) are widely used in magnetic resonance imaging (MRI) but are limited due to Gd3+ leakage risk and low sensitivity. Gd-DOTA enjoys the highest inertness and stability among the clinical GBCAs, and lipophilic 3-phenylpropylamine and 3,3-diphenylpropylamine were linked to Gd-DOTABA in this study, giving Gd-L1 and Gd-L2 for hepatobiliary and vascular MRI, respectively. Both complexes demonstrated superior inertness, with dissociation half-lives in 1 M HCl solution and at 37 °C measured to be around 4 times longer than that of Gd-DOTA. The hepatic MRI performance of Gd-L1 was comparable to commercial Gd-BOPTA as investigated in mice. The r1 of Gd-L2 in the presence of HSA was determined as high as 14.8 mM–1 s–1 (1.4 T and 37 °C), and its blood elimination half-life was determined at around 18 min in a rabbit model, thus making it an effective candidate for vascular MRI.