Design of Mn(1,4-DO2A) derivatives as stable and inert contrast agents for magnetic resonance imaging

作者：Weiyuan Xu, Zheng Cai, Fabio Carniato, Yi Lü, Xinjian Ye, Xinhui Xiao, Jiao Xu, Gengshen Mo, Yinghui Ding, Yong Jian, Xinzhong Ruan, Zhihan Yan, Fangfu Ye, Carlos Platas‐Iglesias, Mauro Botta, Lixiong Dai · 发表于：Communications Chemistry · 年份：2025 · DOI：10.1038/s42004-025-01615-x · 被引用次数：7 · 研究领域：Lanthanide and Transition Metal Complexes、Medical Imaging Techniques and Applications、Advanced MRI Techniques and Applications

Manganese(II) is considered a valuable alternative to gadolinium(III) in developing contrast agents (CAs) for magnetic resonance imaging (MRI). However, due to the labile nature of common Mn(II) complexes, designing ligands that enable stable and inert complexation is essential before clinical application. Mn(1,4-Et4DO2A) bearing four ethyl groups, is found to have a log KMnL as high as 17.86, together with a pMn of 7.52 at pH 7.4. Kinetically, Mn(1,4-Et4DO2A) is approximately 20 times more inert than Mn(1,4-DO2A) in the presence of a 25-fold excess of Zn(II) at pH 6.0 and 37 °C, with the incorporation of a benzoic group to one pendant arm extending the half-life time (t1/2) to around 22 hours. Its r1 is measured as 2.34 and 2.20 mM−1 s−1 at 310 K and 1.5 and 3.0 T, respectively, representing an approximate 50% increase compared to Mn(1,4-DO2A). Mn(1,4-Et4DO2A) shows hepatic preference in mice, and its efficacy in diagnosing orthotopic hepatocellular carcinoma (HCC) is also confirmed. Manganese(II) offers a promising alternative to gadolinium(III) for MRI contrast agents, but stability issues hinder clinical use. Here, the authors develop Mn(1,4-Et4DO2A), a stable and inert complex that demonstrates valuable imaging efficacy and hepatic preference in mice.