Zn2+ Responsive Bimodal Magnetic Resonance Imaging and Fluorescent Imaging Probe Based on a Gadolinium(III) Complex
Zn2+ Responsive Bimodal Magnetic Resonance Imaging and Fluorescent Imaging Probe Based on a Gadolinium(III) Complex
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基于钆(III)络合物的Zn2响应双峰磁共振成像和荧光成像探针
DOI：
10.1021/ic301308z
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发表时间：
2012-09-03
影响因子：
4.6
通讯作者：
Chen, Zhong-Ning
中科院分区：
文献类型：
--
作者：
Luo, Jian;Li, Wei-Sheng;Chen, Zhong-Ning
合成了Zn2+响应双峰磁共振成像(MRI)和发光成像探针GdL。检查了弛豫率和发光特性。当存在0.5当量的Zn2+时，纵向弛豫率在23 MHz和25°C下从3.8 mM(-1) s(-1)增加到5.9 mM(-1) s(-1)，增强了55%，而荧光则增加了7倍。 Zn2+ 响应成像探针在生理 pH 范围内对各种生物相关阴离子和金属离子显示出良好的选择性和耐受性，无论是弛豫度还是发光性。体外体模图像和活细胞共焦荧光图像表明，双峰Zn2+探针通过Zn2+配位，能够有效增强T-1加权成像对比度和发光成像效果，具有优异的细胞膜通透性和生物相容性。光谱和电喷雾电离质谱 (ESI-MS) 研究表明，当 0.5 和 1 当量的 Zn2+ 分别与 GdL 络合物结合时，会形成两种不同的 Zn2+ 结合物质，(GdL)(2)Zn 和 GdLZn。晶体结构测定和镝诱导的O-17 NMR位移（DIS）实验表明，Zn2+与GdL络合后分子量的增加和分子刚性的改善是弛豫增强的主要因素。发光的显着增强是由于 Zn2+ 与 8-磺酰胺喹啉发色团结合后的重原子效应和分子刚性大大增加。
A Zn2+-responsive bimodal magnetic resonance imaging (MRI) and luminescence imaging probe GdL was synthesized. The relaxivity and luminescence properties were examined. In the presence of 0.5 equiv of Zn2+, the longitudinal relaxivity is increased from 3.8 mM(-1) s(-1) to 5.9 mM(-1) s(-1) at 23 MHz and 25 degrees C with 55% enhancement, whereas the fluorescence exhibits a 7-fold increase. The Zn2+ responsive imaging probe shows favorable selectivity and tolerance over a variety of biologically relevant anions and metal ions in physiological pH range for both relaxivity and luminescence. In vitro phantom images and confocal fluorescence images in living cells show that the bimodal Zn2+ probe can effectively enhance T-1-weighted imaging contrast and luminescence imaging effect through Zn2+ coordination with excellent cellmembrane permeability and biocompatibility. Spectral and electrospray ionization mass spectrometry (ESI-MS) studies indicate that two different Zn2+-bound species, (GdL)(2)Zn and GdLZn, are formed when 0.5 and 1 equiv of Zn2+ are bound to GdL complex, respectively. Crystal structural determination and dysprosium-induced O-17 NMR shift (DIS) experiment demonstrate that the increased molecular weight and the improved molecular rigidity upon complexation of Zn2+ with GdL is the primary factor for relaxivity enhancement. Significant enhancement of the luminescence is due to a heavy atom effect and much increased molecular rigidity upon Zn2+ binding to 8-sulfonamidoquinoline chromophore.