Luminescence Studies of Lanthanide Contrast Agents

描述(申请人提供)：磁共振成像(MRI)造影剂的发展对人类健康非常重要，因为MRI诊断越来越重要。这一领域的一个重要新进展是通过化学交换饱和转移(CEST)过程发现了具有磁共振造影剂功能的Ln(111)配合物。与传统的Gd(111)造影剂不同，Ln(111)CEST造影剂可能含有几乎任何顺磁性的Ln(111)。为了开发更有效的造影剂，研究Ln(111)的配位化学，包括水的配体交换速率、配位数及其在Ln(111)系列中的变化是非常重要的。 本研究的目的是利用直接激发(非配体敏化)发光光谱研究Ln(111)造影剂的配位化学。布法罗大学建立的一种新的激光系统将用于这项工作。主要研究内容包括：1)确定Nd(111)、Sm(111)、Eu(111)、Dy(111)和Yb(111)的直接激发发光条件，定量测定配体基团的激发态猝灭常数；2)利用Sm(111)、Dy(111)和Yb(111)的短发光寿命研究8个和9个配位的Ln(111)配合物之间的动态平衡，得到Eu(111)配合物的配位交换速率常数。3)评价含侧醇基团的单核Ln(111)大环配合物和双核Ln(111)配合物作为MRI造影剂的潜力。这项工作将有助于更好地了解Ln(111)配位化学，并将为生物和化学体系中Ln(111)的研究提供新的工具。新的激光系统也将向全国各地的研究人员开放，并将成为Ln(111)发光研究中心的核心。

DESCRIPTION (provided by applicant): The development of magnetic resonance imaging (MRI) contrast agents is important to human health given the increasing importance of MRI diagnostics. An important new development in this area is based on the discovery of Ln(lll) complexes that function as MRI contrast agents by chemical exchange saturation transfer (CEST) processes. Unlike the more conventional Gd(lll) contrast agents, Ln(lll) CEST agents may contain almost any of the paramagnetic Ln(lll). In order to develop more effective contrast agents, it is important to study Ln(lll) coordination chemistry including water ligand exchange rates, coordination number and variations across the Ln(lll) series. The goal of the proposed research is to use direct-excitation (non-ligand sensitized) luminescence spectroscopy of Nd(lll), Sm(lll), Eu(lll), Dy(lll) and Yb(lll) to study the coordination chemistry of Ln(lll) contrast agents. A new laser system set up at the University of Buffalo, will be used for this work. There are three major research objectives including: 1) to determine the conditions for the direct-excitation luminescence of Nd(lll), Sm(lll), Eu(lll), Dy(lll) and Yb(lll) complexes and quantitate selected ligand group excited state quenching constants, 2) to utilize the short luminescence lifetimes of Sm(lll), Dy(lll) and Yb(lll) to study a dynamic equilibrium between eight and nine coordinate Ln(lll) complexes and to obtain rate constants for ligand exchange for Eu(lll) complexes, 3) to evaluate the potential of mononuclear Ln(lll) macrocyclic complexes containing pendent alcohol groups and dinuclear Ln(lll) complexes as MRI contrast agents. This work will contribute to a better basic understanding of Ln(lll) coordination chemistry and will yield new tools for Ln(lll) research in biological and chemical systems. The new laser system will also be available to researchers throughout the country and will be at the heart of a center for Ln(lll) luminescence research.