MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, Max-Planck-Ring 11, 72076 Tübingen, Germany.
Lab of Molecular and Cellular Neuroimaging, International Center for Primate Brain Research (ICPBR), Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Chinese Academy of Science (CAS), Shanghai 200031, China.
Molecules. 2020 Oct 29;25(21):5019. doi: 10.3390/molecules25215019.
Bridged polymacrocyclic ligands featured by structurally different cages offer the possibility of coordinating multiple trivalent lanthanide ions, giving rise to the exploitation of their different physicochemical properties, e.g., multimodal detection for molecular imaging purposes. Intrigued by the complementary properties of optical and MR-based image capturing modalities, we report the synthesis and characterization of the polymetallic Ln(III)-based chelate comprised of two DOTA-amide-based ligands (DOTA-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) bridged via 1,10-diaza-18-crown-6 (DA18C6) motif. The DOTA-amide moieties and the DA18C6 were used to chelate two Eu(III) ions and one Tb(III) ion, respectively, resulting in a multinuclear heterometallic complex . The bimetallic complex without Tb(III), , displayed a strong paramagnetic chemical exchange saturation transfer (paraCEST) effect. Notably, the luminescence spectra of featured mixed emission including the characteristic bands of Eu(III) and Tb(III). The advantageous features of the complex opens new possibilities for the future design of bimodal probes and their potential applicability in CEST MR and optical imaging.
具有不同笼状结构的桥连多环大环配体为配位多个三价镧系元素离子提供了可能性，从而可以利用它们的不同物理化学性质，例如，进行多模态检测以用于分子成像目的。受光学和基于磁共振（MR）成像捕获模式互补特性的启发，我们报告了由两个基于 DOTA-酰胺的配体（DOTA-1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸）通过 1,10-二氮杂-18-冠-6（DA18C6）桥联组成的多金属 Ln（III）配合物的合成和表征。DOTA-酰胺部分和 DA18C6 分别用于螯合两个 Eu（III）离子和一个 Tb（III）离子，从而得到多核异金属配合物。不含 Tb（III）的双金属配合物 ，显示出强顺磁化学交换饱和转移（paraCEST）效应。值得注意的是， 配合物的荧光光谱显示出混合发射特征，包括 Eu（III）和 Tb（III）的特征谱带。配合物 的这些有利特性为设计双模态探针开辟了新的可能性，并为其在 CEST MR 和光学成像中的潜在应用提供了可能性。
