Oxidation-Responsive, Eu^II/III-Based, Multimodal Contrast Agent for Magnetic Resonance and Photoacoustic Imaging

Abstract

We report, for the first time, a multimodal, oxidation-responsive contrast agent for magnetic resonance imaging and photoacoustic imaging that uses the differences in the properties between Eu in the +2 and +3 oxidation states. The enhancement of contrast in T1-weighted magnetic resonance and photoacoustic imaging was observed in the +2 but not in the +3 oxidation state, and the complex is a known chemical exchange saturation transfer agent for magnetic resonance imaging in the +3 oxidation state.

The first example of fluorescence of the solid individual compounds of Eu2+ ion: EuCl2, EuI2, EuBr2

“…The promising use of Eu 2+ FL is also in efficient tricolor lamp phosphors and for visualizing X‐ray images using memory phosphors . Eu 2+ FL could also be usefull to control the valence state of multimodal, oxidation‐responsive contrast agents for magnetic resonance imaging and photoacoustic imaging using differences in the properties between Eu 2+ and Eu 3+ oxidation states . Finally, electronically excited Eu 2+ ions emitting bright blue or green FL have recently been detected as emitters or enhancers in chemiluminescent systems during oxidation of organoaluminum compounds.…”

“…Finally, electronically excited Eu 2+ ions emitting bright blue or green FL have recently been detected as emitters or enhancers in chemiluminescent systems during oxidation of organoaluminum compounds. Most studies on Eu 2+ FL have focused mainly on different Eu 2+ ‐doped solid matrices, containing from 0.01% to several per cent Eu (for example references and references therein). Reports of studies on the FL of divalent lanthanides and the photoluminescence (PL) of simple individual compounds such as EuX 2 (X = Cl, Br, I), EuO, EuS, EuCO 3 and others are absent from the literature.…”

Recent Advances of Bioresponsive Nano-Sized Contrast Agents for Ultra-High-Field Magnetic Resonance Imaging

“…Molecular imaging enables the quantitative characterization and measurement of biological diagnosis at the cellular and molecular level, which will inevitably advance the modern and future medical imaging and diagnosis (Wu and Shu, 2018;. However, the current critical issue lies in developing novel and appropriate contrast agents to meet the biological compatibility for different species (Basal et al, 2017). MRI with nanoparticle contrast agent offers one desired solution to realize molecular imaging.…”

Synthesis, Characterization, and Handling of EuII-Containing Complexes for Molecular Imaging Applications

“…Divalent europium is a paramagnetic ion with photophysical and electrochemical properties that can be modulated with coordination chemistry (Gansow et al, 1977 ; Yee et al, 1980 , 1983 ; Sabbatini et al, 1982 , 1984 ; Antonio and Soderholm, 1996 ; Jiang et al, 1998 ; Shipley et al, 1999 ; Burai et al, 2000 ; Soderholm et al, 2002 ; Botta et al, 2003 ; Christoffers and Starynowicz, 2008 ; Gamage et al, 2010 ; Pan et al, 2011 ; Garcia and Allen, 2012a , b ; Gál et al, 2013 ; Kelly et al, 2015 ; Kuda-Wedagedara et al, 2015 ; Regueiro-Figueroa et al, 2015 ; Allen, 2016 ; Ekanger et al, 2016a , 2017 ; Jin et al, 2016 ; Vanek et al, 2016 ; Basal et al, 2017a , b ; Burnett et al, 2017 ; Kawasaki et al, 2017 ; Corbin et al, 2018 ; Jenks et al, 2018 ). Because of these tunable properties, divalent europium complexes have potential use as molecular-imaging probes that sense O 2 , which is important because O 2 imbalances are often correlated with disease (Shweiki et al, 1992 ; Barnham et al, 2004 ; Mattson, 2004 ; Lin and Beal, 2006 ; Park et al, 2008 ; Facciabene et al, 2011 ).…”