Zairov Rustem, Khakimullina Gulshat, Podyachev Sergey, Nizameev Irek, Safiullin Georgy, Amirov Rustem, Vomiero Alberto, Mustafina Asiya
A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences, Arbuzov str., 8, 420088, Kazan, Russia.
Kazan (Volga region) Federal university, Kremlyovskaya str., 18, 420008, Kazan, Russia.
Sci Rep. 2017 Oct 25;7(1):14010. doi: 10.1038/s41598-017-14409-6.
Today, nanostructure-based contrast agents (CA) are emerging in the field of magnetic resonance imaging (MRI). Their sensitivity is reported as greatly improved in comparison to commercially used chelate-based ones. The present work is aimed at revealing the factors governing the efficiency of longitudinal magnetic relaxivity (r) in aqueous colloids of core-shell Gd(III)-based nanoparticles. We report for the first time on hydration number (q) of gadolinium(III) as a substantial factor in controlling r values of polyelectrolyte-stabilized nanoparticles built from water insoluble complexes of Gd(III). The use of specific complex structure enables to reveal the impact of the inner-sphere hydration number on both r values for the Gd(III)-based nanoparticles and the photophysical properties of their luminescent Tb(III) and Eu(III) counterparts. The low hydration of TTA-based Gd(III) complexes (q ≈ 1) agrees well with the poor relaxivity values (r = 2.82 mMs and r = 3.95 mMs), while these values tend to increase substantially (r = 12.41 mMs, r = 14.36 mMs) for aqueous Gd(III)-based colloids, when macrocyclic 1,3-diketonate is applied as the ligand (q ≈ 3). The regularities obtained in this work are fundamental in understanding the efficiency of MRI probes in the fast growing field of nanoparticulate contrast agents.
如今，基于纳米结构的造影剂（CA）正在磁共振成像（MRI）领域崭露头角。据报道，与市售的基于螯合物的造影剂相比，它们的灵敏度有了显著提高。目前的工作旨在揭示控制核壳型钆（III）基纳米粒子水胶体中纵向磁弛豫率（r）效率的因素。我们首次报道了钆（III）的水合数（q）是控制由钆（III）的水不溶性配合物构建的聚电解质稳定纳米粒子r值的一个重要因素。使用特定的配合物结构能够揭示内球水合数对钆（III）基纳米粒子的r值及其发光铽（III）和铕（III）对应物的光物理性质的影响。基于噻吩甲酰三氟丙酮的钆（III）配合物的低水合度（q≈1）与较差的弛豫率值（r = 2.82 mM s和r = 3.95 mM s）非常吻合，而当应用大环1,3 - 二酮作为配体（q≈3）时，基于钆（III）的水胶体的这些值往往会大幅增加（r = 12.41 mM s，r = 14.36 mM s）。这项工作中获得的规律对于理解纳米颗粒造影剂快速发展领域中MRI探针的效率至关重要。
