Hydration number: crucial role in nuclear magnetic relaxivity of Gd(III) chelate-based nanoparticles. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Zairov, Rustem; Khakimullina, Gulshat; Podyachev, Sergey; Nizameev, Irek; Safiullin, Georgy; Amirov, Rustem; Vomiero, Alberto; Mustafina, Asiya
• Is Part Of: Scientific reports. Volume 7:Issue 1(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-12
• Subjects: Natural history -- Research -- Periodicals; Biology -- Research -- Periodicals; Physical sciences -- Research -- Periodicals; Earth sciences -- Research -- Periodicals; Environmental sciences -- Research -- Periodicals; 502.85
• DOI: 10.1038/s41598-017-14409-6
• Languages: English
• ISSNs: 2045-2322

Abstract

Abstract 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 (r1 ) 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 r1 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 r1 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 (r1 = 2.82 mM−1 s−1 and r2 = 3.95 mM−1 s−1 ), while these values tend to increase substantially (r1 = 12.41 mM−1 s−1, r2 = 14.36 mM−1 s−1 ) 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.