Paramagnetic lanthanide chelates for multicontrast MRI

Cakić, Nevenka; Savić, Tanja; Stricker-Shaver, Janice; Truffault, Vincent; Platas‐Iglesias, Carlos; Mirkes, C; Pohmann, R; Scheffler, Klaus; Angelovski, Goran

doi:10.1039/c6cc04011j

Cited by 27 publications

(70 citation statements)

References 23 publications

(36 reference statements)

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“…The problem of multiple isomers is not limited to tetra-substituted macrocyclic derivatives. In fact, many DOTA analogs with only one or two fluorinated arms are present in solution as more than one isomer ( 2 – 4 ), the percentage of which varies according to the lanthanide (Kenwright et al, 2008 ; Chalmers et al, 2010 ; Placidi et al, 2013 ; Cakic et al, 2016 ).…”

Section: Improving the Sensitivity Of 19 F Probesmentioning

confidence: 99%

“… Chemical structures of non-responsive paramagnetic 19 F probes ( 1 , Kim et al, 1997 ; 2 , Cakic et al, 2016 ; 3 , Placidi et al, 2013 ; 4 , Chalmers et al, 2010 ; 5–6 , Chalmers et al, 2011a ; 7 , Chalmers et al, 2011a , b ; 8–9 , Davies et al, 2015 ; 10 , Jiang et al, 2011 ; 11 , Chalmers et al, 2010 ; 12 , Srivastava et al, 2017a , b ; 13 , Blahut et al, 2016 , 2017 ). …”

Section: Improving the Sensitivity Of 19 F Probesmentioning

confidence: 99%

“…In general, the stronger relaxing metals with the higher μ eff near 10, Tb III , Dy III , and Ho III decrease both T 1 and T 2 the most. Lanthanides such as Er III , Tm III , and in the extreme case Gd III , have lower T 2 / T 1 ratio and hence lower sensitivity (Table 2 ) (Chalmers et al, 2010 , 2011a , b ; Jiang et al, 2011 ; Harvey et al, 2012b ; Placidi et al, 2013 ; Blahut et al, 2016 ; Cakic et al, 2016 ; Srivastava et al, 2017b ). Do note that the PRE effect is determined by other parameters beyond the μ eff of the metal ion; it is also dependent on the magnetic field strength and on the distance separating the 19 F nuclei and the paramagnetic metal ion (Equation 1–5).…”

Section: Improving the Sensitivity Of 19 F Probesmentioning

confidence: 99%

“…Two examples of dual 19 F-CEST agents have been reported. A fluorinated Eu-DOTAm-Gly complex with two trans trifluoromethyl groups ( 2 , Figure 1 ) generated sufficient 19 F and CEST contrast in vitro despite multiple isomers in solution (Cakic et al, 2016 ). Unfortunately, the contrast agent was not detected in ex vivo by 19 F MRI, possibly due to interactions with tissues that substantially reduced T 2.…”

Section: Exploiting the Metal Ion To Design Responsive Fluorine Probementioning

confidence: 99%

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Fluorinated Paramagnetic Complexes: Sensitive and Responsive Probes for Magnetic Resonance Spectroscopy and Imaging

2018

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Fluorine magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) of chemical and physiological processes is becoming more widespread. The strength of this technique comes from the negligible background signal in in vivo 19F MRI and the large chemical shift window of 19F that enables it to image concomitantly more than one marker. These same advantages have also been successfully exploited in the design of responsive 19F probes. Part of the recent growth of this technique can be attributed to novel designs of 19F probes with improved imaging parameters due to the incorporation of paramagnetic metal ions. In this review, we provide a description of the theories and strategies that have been employed successfully to improve the sensitivity of 19F probes with paramagnetic metal ions. The Bloch-Wangsness-Redfield theory accurately predicts how molecular parameters such as internuclear distance, geometry, rotational correlation times, as well as the nature, oxidation state, and spin state of the metal ion affect the sensitivity of the fluorine-based probes. The principles governing the design of responsive 19F probes are subsequently described in a “how to” guide format. Examples of such probes and their advantages and disadvantages are highlighted through a synopsis of the literature.

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Section: Improving the Sensitivity Of 19 F Probesmentioning

confidence: 99%

Section: Improving the Sensitivity Of 19 F Probesmentioning

confidence: 99%

Section: Improving the Sensitivity Of 19 F Probesmentioning

confidence: 99%

Section: Exploiting the Metal Ion To Design Responsive Fluorine Probementioning

confidence: 99%

See 2 more Smart Citations

Fluorinated Paramagnetic Complexes: Sensitive and Responsive Probes for Magnetic Resonance Spectroscopy and Imaging

2018

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“…The uptaken materials can be i) recycled back (in early and recycling endosomes), or ii) degraded (in late endosomes and lysosomes) . Along the endocytic pathway, the intravesicular pH decreases reaching values between 6.0–6.8 in early endosomes and 4.5–5.5 in late endosomes and lysosomes …”

Section: Introductionmentioning

confidence: 99%

Modulation of the Prototropic Exchange Rate in pH‐Responsive Yb‐HPDO3A Derivatives as ParaCEST Agents

et al. 2018

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The aim of this work was to design new pH‐sensitive paramagnetic chemical exchange saturation transfer (paraCEST) agents with a more acidic pH readout window with respect to the Yb complex of the 10‐(2‐hydroxypropyl)‐1,4,7,10‐ tetraazacyclododecane‐1,4,7‐triacetic acid (HPDO3A). In particular, three HPDO3A derivatives have been synthesized by substituting the methyl group on the 2‐hydroxypropyl arm with the electron withdrawing substituents –CF3, –CH2NH2 and –CH2OH. The Yb complexes have been characterized in terms of i) number and relative abundance of isomers present and, ii) pH sensitivity range in CEST applications. The influence of the introduced substituents on the –OH proton acidity and kex has been investigated and the new agents have been compared with the parent Yb‐HPDO3A. All complexes showed an increased acidity and an enhanced exchange rate of the –OH proton. As a consequence, the pH‐CEST sensitivity has been shifted to more acidic values. Eventually, the –CH2OH bearing derivative has been tested to assess the intra‐endosomal pH which is too acidic to be determined with Yb‐HPDO3A.

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Definition of the Labile Capping Bond Effect in Lanthanide Complexes

Rodríguez-Rodríguez

Regueiro‐Figueroa

Esteban‐Gómez

et al. 2016

Chemistry A European J

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Abstract:We report two novel macrocyclic ligands containing a cyclen unit, a methyl group, a picolinate arm and two acetate pendant arms attached to two nitrogen atoms of the macrocycle either in trans (1,7-H3Medo2ampa) or in cis (1,4-H3Medo2ampa) positions. These ligands provide eight-coordination to the Ln 3+ ions leaving a coordination position available for a water molecule that occupies a capping position in the twisted square antiprismatic polyhedron (1,4-H3Medo2ampa) or one of the positions of the square antiprism (1,7-H3Medo2ampa). The charge neutral [Gd(1,7-Medo2ampa)] complex presents an unprecedentedly low water exchange rate (kex 298 = 8.8 10 3 s -1 ), while water exchange in [Gd(1,] is three orders of magnitude faster (kex 298 = 6.6 10 6 s -1 ). These results showcase the labile capping bond phenomenon: a ligand occupying a capping position is hindered by the environment and thus is intrinsically labile.

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Paramagnetic lanthanide chelates for multicontrast MRI

Cited by 27 publications

References 23 publications

Fluorinated Paramagnetic Complexes: Sensitive and Responsive Probes for Magnetic Resonance Spectroscopy and Imaging

Fluorinated Paramagnetic Complexes: Sensitive and Responsive Probes for Magnetic Resonance Spectroscopy and Imaging

Modulation of the Prototropic Exchange Rate in pH‐Responsive Yb‐HPDO3A Derivatives as ParaCEST Agents

Definition of the Labile Capping Bond Effect in Lanthanide Complexes

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