Multifunctional Rare-Earth Vanadate Nanoparticles: Luminescent Labels, Oxidant Sensors, and MRI Contrast Agents
Multifunctional Rare-Earth Vanadate Nanoparticles: Luminescent Labels, Oxidant Sensors, and MRI Contrast Agents
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DOI：
10.1021/nn504170x
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发表时间：
2014-11-01
期刊：
影响因子：
17.1
通讯作者：
Alexandrou, Antigoni
中科院分区：
文献类型：
--
作者：
Abdesselem, Mouna;Schoeffel, Markus;Alexandrou, Antigoni
收集关于多个病理生理参数的信息对于理解复杂的病理是必不可少的，特别是在个体间差异很大的情况下。我们报道了多功能纳米粒子，它们是磁共振成像(MRI)中的发光探针、氧化剂传感器和造影剂。钒酸钇基质中的Eu3+离子已被证明能发出强烈的、不闪烁的、稳定的发光。在Eu3+被可逆光还原为Eu2+，并被H_2O_2等氧化剂重新氧化后，导致发光的调制，时间和空间分辨的光学氧化剂检测是可行的。此外，顺磁性Gd3+的加入还赋予了该体系质子弛豫增强性质。我们合成并表征了直径为5 nm或30 nm的纳米粒子，其组成为GdVO4和Gd0.6Eu0.4VO4。这些颗粒保留了YVO4：Eu的发光和氧化剂检测特性。此外，在20 MHz下，直径为5 nm的GdVO4和Gd0.6Eu0.4VO4纳米粒子的质子弛豫度高于商品化的Gd3+络合化合物Dotarem。核磁共振色散谱显示，在10 MHz以上，弛豫系数增加。络合滴定表明稀土的浸出可以忽略不计。将5 nm纳米粒子注射到小鼠体内，30min后用MRI观察其在肝脏和膀胱的浓集。因此，这些多功能的稀土钒酸盐纳米颗粒为同时进行光学和磁共振检测铺平了道路，特别是在广泛的生理和病理生理条件下的体内定位进化和活性氧物种检测。
Collecting information on multiple pathophysiological parameters is essential for understanding complex pathologies, especially given the large interindividual variability. We report here multifunctional nanoparticles which are luminescent probes, oxidant sensors, and contrast agents in magnetic resonance imaging (MRI). Eu3+ ions in an yttrium vanadate matrix have been demonstrated to emit strong, nonblinking, and stable luminescence. Time- and space-resolved optical oxidant detection is feasible after reversible photoreduction of Eu3+ to Eu2+ and reoxidation by oxidants, such as H2O2, leading to a modulation of the luminescence emission. The incorporation of paramagnetic Gd3+ confers in addition proton relaxation enhancing properties to the system. We synthesized and characterized nanoparticles of either 5 or 30 nm diameter with compositions of GdVO4 and Gd0.6Eu0.4VO4. These particles retain the luminescence and oxidant detection properties of YVO4:Eu. Moreover, the proton relaxivity of GdVO4 and Gd0.6Eu0.4VO4 nanoparticles of 5 nm diameter is higher than that of the commercial Gd3+ chelate compound Dotarem at 20 MHz. Nuclear magnetic resonance dispersion spectroscopy showed a relaxivity increase above 10 MHz. Complexometric titration indicated that rare-earth leaching is negligible. The 5 nm nanoparticles injected in mice were observed with MRI to concentrate in the liver and the bladder after 30 min. Thus, these multifunctional rare-earth vanadate nanoparticles pave the way for simultaneous optical and magnetic resonance detection, in particular, for in vivo localization evolution and reactive oxygen species detection in a broad range of physiological and pathophysiological conditions.