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Nielsen LG, Andersen HOB, Kenwright AM, Platas-Iglesias C, So Rensen TJ. Using Chiral Auxiliaries to Mimic the Effect of Chiral Media on the Structure of Lanthanide(III) Complexes Common in Bioimaging and Diagnostic MRI. Inorg Chem 2024; 63:7560-7570. [PMID: 38610098 DOI: 10.1021/acs.inorgchem.3c01589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2024]
Abstract
[Ln·DOTA]- complexes and systems derived therefrom are commonly used in MRI and optical bioimaging. These lanthanide(III) complexes are chiral, and, in solution, they are present in four forms, with two sets of enantiomers, with the ligand donors arranged in either a square antiprismatic, SAP, or twisted square antiprismatic geometry, TSAP. This complicated speciation is found in laboratory samples. To investigate speciation in biological media, when Ln·DOTA-like complexes interact with chiral biomolecules, six Eu·DOTA-monoamide complexes were prepared and investigated by using 1D and 2D 1H NMR. To emulate the chirality of biological media, the amide pendant arm was modified with one or two chiral centers. It is known that a chiral center on the DOTA scaffold significantly influences the properties of the system. Here, it was found that chirality much further away from the metal center changes the available conformational space and that both chiral centers and amide cis/trans isomerism may need to be considered─a fact that, for the optically enriched materials, led to the conclusion that eight chemically different forms may need to be considered, instead of the four forms necessary for DOTA. The results reported here clearly demonstrate the diverse speciation that must be considered when correlating an observation to a structure of a lanthanide(III) complex.
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Affiliation(s)
- Lea Gundorff Nielsen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, Ko̷benhavn Ø DK2100, Denmark
| | - Helene O B Andersen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, Ko̷benhavn Ø DK2100, Denmark
| | - Alan M Kenwright
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Carlos Platas-Iglesias
- Centro Interdisciplinar de Química e Bioloxía (CICA) and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña, Galicia 15071, Spain
| | - Thomas Just So Rensen
- Department of Chemistry & Nano-Science Center, University of Copenhagen, Universitetsparken 5, Ko̷benhavn Ø DK2100, Denmark
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2
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Markiewicz KH, Marmuse L, Mounsamy M, Billotey C, Destarac M, Mingotaud C, Marty JD. Assembly of Poly(vinylphosphonic acid)-Based Double Hydrophilic Block Copolymers by Gadolinium Ions for the Formation of Highly Stable MRI Contrast Agents. ACS Macro Lett 2022; 11:1319-1324. [PMID: 36343111 DOI: 10.1021/acsmacrolett.2c00489] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mixing double-hydrophilic block copolymers containing a poly(vinylphosphonic acid) block with gadolinium ions in water leads to the spontaneous formation of polymeric nanoparticles. With an average diameter near 20 nm, the nanoparticles are stable after dilution or change of pH and ionic strength. High magnetic relaxivities were measured in vitro, and in vivo magnetic resonance imaging on rats demonstrates the high potential of such polymeric assemblies.
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Affiliation(s)
- Karolina H Markiewicz
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse, Cedex 9, France.,Faculty of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland
| | - Laurence Marmuse
- EMR 3738 Ciblage Thérapeutique en Oncologie, Université de Lyon, Université Jean Monnet, Hospices Civils de Lyon, 42023 Saint-Etienne, Cedex 2, France
| | - Margaux Mounsamy
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse, Cedex 9, France
| | - Claire Billotey
- EMR 3738 Ciblage Thérapeutique en Oncologie, Université de Lyon, Université Jean Monnet, Hospices Civils de Lyon, 42023 Saint-Etienne, Cedex 2, France
| | - Mathias Destarac
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse, Cedex 9, France
| | - Christophe Mingotaud
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse, Cedex 9, France
| | - Jean-Daniel Marty
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Paul Sabatier, 118, route de Narbonne, 31062 Toulouse, Cedex 9, France
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3
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Barré R, Mouchel dit Leguerrier D, Ruet Q, Fedele L, Imbert D, Martel‐Frachet V, Fries PH, Molloy JK, Thomas F. Lanthanide Complexes (Gd III and Eu III ) Based on a DOTA-TEMPO Platform for Redox Monitoring via Relaxivity. Chem Asian J 2022; 17:e202200544. [PMID: 35796463 PMCID: PMC9544908 DOI: 10.1002/asia.202200544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/06/2022] [Indexed: 11/27/2022]
Abstract
Three lanthanide complexes (Ln=Gd, Eu) based on a DO3 A ([Ln(L1 )]) or DO2 A ([Ln(L2-3 )]+ ) platform appended by a redox active TEMPO-based arm were prepared. Complex [Ln(L2 )]+ shows an alkyne arm, offering the possibility of postfunctionalization by click reaction to yield [Ln(L3 )]+ . The complexes demonstrate a redox response whereby the hydroxylamine, nitroxide and oxoammonium forms of the arm can be obtained in turn. Luminescence measurements on the europium complexes support an octadentate (L1 , L3 ) or heptadentate (L2 ) chelation by the ligand, with one water molecule in the inner coordination sphere. The relaxivity was determined from 20 kHz to 30 MHz by fast-field cycling NMR. The three GdIII complexes under their hydroxylamine form [Gd(L1 )] and [Gd(L2-3 )]+ show r1 values of 7.0, 5.1 and 5.0 mM-1 s-1 (30 KHz), which increase to 8.8, 5.5 and 6.1 mM-1 s-1 in the nitroxide form. The radical complexes are not toxic against M21 cell lines, at least up to 40 μM. By using EPR spectroscopy we establish that they do not penetrate the cells with the exception of [Eu(L2 )]+ .
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Affiliation(s)
| | | | - Quentin Ruet
- Institute for Advanced BiosciencesINSERM U1209UMR CNRS 5309Grenoble Alpes University38700La TroncheFrance
- EPHEPSL Research University75014ParisFrance
| | - Lionel Fedele
- Univ. Grenoble AlpesCEACNRSIRIG-LCBM38000GrenobleFrance
| | - Daniel Imbert
- Univ. Grenoble AlpesCEACNRSIRIG-LCBM38000GrenobleFrance
| | - Véronique Martel‐Frachet
- Institute for Advanced BiosciencesINSERM U1209UMR CNRS 5309Grenoble Alpes University38700La TroncheFrance
- EPHEPSL Research University75014ParisFrance
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Thi Kim Dung D, Umezawa M, Ohnuki K, Nigoghossian K, Okubo K, Kamimura M, Yamaguchi M, Fujii H, Soga K. The influence of Gd-DOTA ratios conjugating PLGA-PEG micelles encapsulated IR-1061 in bimodal over–1000 nm near–infrared fluorescence and magnetic resonance imaging. Biomater Sci 2022; 10:1217-1230. [DOI: 10.1039/d1bm01574e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multimodal imaging can provide multidimensional information for understanding concealed microstructures or bioprocesses in biological objects. The combination of over–1000 nm near–infrared (OTN–NIR) fluorescence imaging and magnetic resonance (MR) imaging is...
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Mallik R, Saha M, Mukherjee C. Porous Silica Nanospheres with a Confined Mono(aquated) Mn(II)-Complex: A Potential T1- T2 Dual Contrast Agent for Magnetic Resonance Imaging. ACS APPLIED BIO MATERIALS 2021; 4:8356-8367. [PMID: 35005912 DOI: 10.1021/acsabm.1c00937] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Magnetic resonance imaging has emerged as an indispensable imaging modality for the early-stage diagnosis of many diseases. The imaging in the presence of a contrast agent is always advantageous, as it mitigates the low-sensitivity issue of the measurements and provides excellent contrast in the acquired images even in a short acquisition time. However, the stability and high relaxivity of the contrast agents remained a challenge. Here, molecules of a mononuclear, mono(aquated), thermodynamically stable [log KMnL = 14.80(7) and pMn = 8.97] Mn(II)-complex (1), based on a hexadentate pyridine-picolinate unit-containing ligand (H2PyDPA), were confined within a porous silica nanosphere in a noncovalent fashion to render a stable nanosystem, complex 1@SiO2NP. The entrapped complex 1 (complex 1@SiO2) exhibited r1 = 8.46 mM-1 s-1 and r2 = 33.15 mM-1 s-1 at pH = 7.4, 25 °C, and 1.41 T in N-(2-hydroxyethyl)piperazine-N'-ethanesulfonic acid buffer. The values were about 2.9 times higher compared to the free (unentrapped)-complex 1 molecules. The synthesized complex 1@SiO2NP interacted significantly with albumin protein and consequently boosted both the relaxivity values to r1 = 24.76 mM-1 s-1 and r2 = 63.96 mM-1 s-1 at pH = 7.4, 37 °C, and 1.41 T. The kinetic inertness of the entrapped molecules was established by recognizing no appreciable change in the r1 value upon challenging complex 1@SiO2NP with 30 and 40 times excess of Zn(II) ions at pH 6 and 25 °C. The water molecule coordinated to the Mn(II) ion in complex 1@SiO2 was also impervious to the physiologically relevant anions (bicarbonate, biphosphate, and citrate) and pH of the medium. Thus, it ensured the availability of the inner-coordination site of complex 1 for the coordination of water molecules in the biological media. The concentration-dependent changes in image intensities in T1- and T2-weighted phantom images and uptake of the nanoparticles by the HeLa cell put forward the biocompatible complex 1@SiO2NP as a potential dual-mode MRI contrast agent, an alternative to Gd(III)-containing contrast agents.
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Affiliation(s)
- Riya Mallik
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Muktashree Saha
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Chandan Mukherjee
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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Fe-HBED Analogs: A Promising Class of Iron-Chelate Contrast Agents for Magnetic Resonance Imaging. CONTRAST MEDIA & MOLECULAR IMAGING 2019; 2019:8356931. [PMID: 31969797 PMCID: PMC6961518 DOI: 10.1155/2019/8356931] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/21/2019] [Indexed: 12/26/2022]
Abstract
Contrast-enhanced magnetic resonance imaging is an essential tool for disease diagnosis and management; all marketed clinical magnetic resonance imaging (MRI) contrast agents (CAs) are gadolinium (Gd) chelates and most are extracellular fluid (ECF) agents. After intravenous injection, these agents rapidly distribute to the extracellular space and are also characterized by low serum protein binding and predominant renal clearance. Gd is an abiotic element with no biological recycling processes; low levels of Gd have been detected in the central nervous system and bone long after administration. These observations have prompted interest in the development of new MRI contrast agents based on biotic elements such as iron (Fe); Fe-HBED (HBED = N,N′-bis(2-hydroxyphenyl)ethylenediamine-N,N′-diacetic acid), a coordinatively saturated iron chelate, is an attractive MRI CA platform suitable for modification to adjust relaxivity and biodistribution. Compared to the parent Fe-HBED, the Fe-HBED analogs reported here have lower serum protein binding and higher relaxivity as well as lower relative liver enhancement in mice, comparable to that of a representative gadolinium-based contrast agent (GBCA). Fe-HBED analogs are therefore a promising class of non-Gd ECF MRI CA.
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Urbanovský P, Kotek J, Carniato F, Botta M, Hermann P. Lanthanide Complexes of DO3A-(Dibenzylamino)methylphosphinate: Effect of Protonation of the Dibenzylamino Group on the Water-Exchange Rate and the Binding of Human Serum Albumin. Inorg Chem 2019; 58:5196-5210. [PMID: 30942072 DOI: 10.1021/acs.inorgchem.9b00267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Protonation of a distant, noncoordinated group of metal-based magnetic resonance imaging contrast agents potentially changes their relaxivity. The effect of a positive charge of the drug on the human serum albumin (HSA)-drug interaction remains poorly understood as well. Accordingly, a (dibenzylamino)methylphosphinate derivative of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) was efficiently synthesized using pyridine as the solvent for a Mannich-type reaction of tBu3DO3A, formaldehyde, and Bn2NCH2PO2H2 ethyl ester. The ligand protonation and metal ion (Gd3+, Cu2+, and Zn2+) stability constants were similar to those of the parent DOTA, whereas the basicity of the side-chain amino group of the complexes (log KA = 5.8) was 1 order of magnitude lower than that of the free ligand (log KA = 6.8). The presence of one bound water molecule in both deprotonated and protonated forms of the gadolinium(III) complex was deduced from the solid-state X-ray diffraction data [gadolinium(III) and dysprosium(III)], from the square antiprism/twisted square antiprism (SA/TSA) isomer ratio along the lanthanide series, from the fluorescence data of the europium(III) complex, and from the 17O NMR measurements of the dysprosium(III) and gadolinium(III) complexes. In the gadolinium(III) complex with the deprotonated amino group, water exchange is extremely fast (τM = 6 ns at 25 °C), most likely thanks to the high abundance of the TSA isomer and to the presence of a proximate protonable group, which assists the water-exchange process. The interaction between lanthanide(III) complexes and HSA is pH-dependent, and the deprotonated form is bound much more efficaciously (∼13% and ∼70% bound complex at pH = 4 and 7, respectively). The relaxivities of the complex and its HSA adduct are also pH-dependent, and the latter is approximately 2-3 times increased at pH = 4-7. The relaxivity for the supramolecular HSA-complex adduct ( r1b) is as high as 52 mM-1 s-1 at neutral pH (at 20 MHz and 25 °C). The findings of this study stand as a proof-of-concept, showing the ability to manipulate an albumin-drug interaction, and thus the blood pool residence time of the drug, by introducing a positive charge in a side-chain amino group.
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Affiliation(s)
- Peter Urbanovský
- Department of Inorganic Chemistry , Universita Karlova (Charles University) , Hlavova 2030 , 12843 Prague 2 , Czech Republic
| | - Jan Kotek
- Department of Inorganic Chemistry , Universita Karlova (Charles University) , Hlavova 2030 , 12843 Prague 2 , Czech Republic
| | - Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica , Università del Piemonte Orientale "A. Avogadro" , Viale T. Michel 11 , 15121 Alessandria , Italy
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica , Università del Piemonte Orientale "A. Avogadro" , Viale T. Michel 11 , 15121 Alessandria , Italy
| | - Petr Hermann
- Department of Inorganic Chemistry , Universita Karlova (Charles University) , Hlavova 2030 , 12843 Prague 2 , Czech Republic
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Wahsner J, Gale EM, Rodríguez-Rodríguez A, Caravan P. Chemistry of MRI Contrast Agents: Current Challenges and New Frontiers. Chem Rev 2019; 119:957-1057. [PMID: 30350585 PMCID: PMC6516866 DOI: 10.1021/acs.chemrev.8b00363] [Citation(s) in RCA: 849] [Impact Index Per Article: 169.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tens of millions of contrast-enhanced magnetic resonance imaging (MRI) exams are performed annually around the world. The contrast agents, which improve diagnostic accuracy, are almost exclusively small, hydrophilic gadolinium(III) based chelates. In recent years concerns have arisen surrounding the long-term safety of these compounds, and this has spurred research into alternatives. There has also been a push to develop new molecularly targeted contrast agents or agents that can sense pathological changes in the local environment. This comprehensive review describes the state of the art of clinically approved contrast agents, their mechanism of action, and factors influencing their safety. From there we describe different mechanisms of generating MR image contrast such as relaxation, chemical exchange saturation transfer, and direct detection and the types of molecules that are effective for these purposes. Next we describe efforts to make safer contrast agents either by increasing relaxivity, increasing resistance to metal ion release, or by moving to gadolinium(III)-free alternatives. Finally we survey approaches to make contrast agents more specific for pathology either by direct biochemical targeting or by the design of responsive or activatable contrast agents.
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Affiliation(s)
- Jessica Wahsner
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Eric M. Gale
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Aurora Rodríguez-Rodríguez
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Peter Caravan
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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Caravan P, Esteban-Gómez D, Rodríguez-Rodríguez A, Platas-Iglesias C. Water exchange in lanthanide complexes for MRI applications. Lessons learned over the last 25 years. Dalton Trans 2019; 48:11161-11180. [DOI: 10.1039/c9dt01948k] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Coordination chemistry offers convenient strategies to modulate the exchange of coordinated water molecules in lanthanide-based contrast agents.
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Affiliation(s)
- Peter Caravan
- The Institute for Innovation in Imaging and the A. A. Martinos Center for Biomedical Imaging
- Massachusetts General Hospital
- Harvard Medical School
- Charlestown
- USA
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química
- Universidade da Coruña
- 15008 A Coruña
- Spain
| | - Aurora Rodríguez-Rodríguez
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química
- Universidade da Coruña
- 15008 A Coruña
- Spain
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química
- Universidade da Coruña
- 15008 A Coruña
- Spain
- The Institute for Innovation in Imaging and the A. A. Martinos Center for Biomedical Imaging
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Phukan B, Malikidogo KP, Bonnet CS, Tóth É, Mondal S, Mukherjee C. A Bishydrated, Eight–Coordinate Gd(III) Complex with Very Fast Water Exchange: Synthesis, Characterization, and Phantom MR Imaging. ChemistrySelect 2018. [DOI: 10.1002/slct.201801629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Bedika Phukan
- Department of ChemistryIndian Institute of Technology Guwahati, Guwahati 781039, Assam India
| | - Kyangwi P. Malikidogo
- Centre de Biophysique MoléculaireCNRS, UPR 4301Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| | - Célia S. Bonnet
- Centre de Biophysique MoléculaireCNRS, UPR 4301Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| | - Éva Tóth
- Centre de Biophysique MoléculaireCNRS, UPR 4301Université d'Orléans, rue Charles Sadron, 45071 Orléans, France
| | - Samsuzzoha Mondal
- Department of Chemical SciencesTata Institute of Fundamental Research 1 Homi Bhabha Road, Colaba, Mumbai 400005 India
| | - Chandan Mukherjee
- Department of ChemistryIndian Institute of Technology Guwahati, Guwahati 781039, Assam India
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Dai L, Jones CM, Chan WTK, Pham TA, Ling X, Gale EM, Rotile NJ, Tai WCS, Anderson CJ, Caravan P, Law GL. Chiral DOTA chelators as an improved platform for biomedical imaging and therapy applications. Nat Commun 2018; 9:857. [PMID: 29487362 PMCID: PMC5829242 DOI: 10.1038/s41467-018-03315-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 02/02/2018] [Indexed: 11/28/2022] Open
Abstract
Despite established clinical utilisation, there is an increasing need for safer, more inert gadolinium-based contrast agents, and for chelators that react rapidly with radiometals. Here we report the syntheses of a series of chiral DOTA chelators and their corresponding metal complexes and reveal properties that transcend the parent DOTA compound. We incorporated symmetrical chiral substituents around the tetraaza ring, imparting enhanced rigidity to the DOTA cavity, enabling control over the range of stereoisomers of the lanthanide complexes. The Gd chiral DOTA complexes are shown to be orders of magnitude more inert to Gd release than [GdDOTA]−. These compounds also exhibit very-fast water exchange rates in an optimal range for high field imaging. Radiolabeling studies with (Cu-64/Lu-177) also demonstrate faster labelling properties. These chiral DOTA chelators are alternative general platforms for the development of stable, high relaxivity contrast agents, and for radiometal complexes used for imaging and/or therapy. MRI contrast agents containing the rare earth metal gadolinium are very effective, yet unstable and thus potentially hazardous. Here, the authors developed complexes between gadolinium and the scaffolding compound DOTA with increased stability, which also lend themselves to radiometal labelling.
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Affiliation(s)
- Lixiong Dai
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Chloe M Jones
- The Athinoula A. Martinos Center for Biomedical Imaging, The Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, 02129, United States
| | - Wesley Ting Kwok Chan
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Tiffany A Pham
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, United States
| | - Xiaoxi Ling
- Department of Medicine, University of Pittsburgh, Pittsburgh, 15261, Pennsylvania, United States
| | - Eric M Gale
- The Athinoula A. Martinos Center for Biomedical Imaging, The Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, 02129, United States
| | - Nicholas J Rotile
- The Athinoula A. Martinos Center for Biomedical Imaging, The Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, 02129, United States
| | - William Chi-Shing Tai
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Carolyn J Anderson
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, United States. .,Department of Medicine, University of Pittsburgh, Pittsburgh, 15261, Pennsylvania, United States. .,Departments of Pharmacology & Chemical Biology and Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, United States.
| | - Peter Caravan
- The Athinoula A. Martinos Center for Biomedical Imaging, The Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, 02129, United States.
| | - Ga-Lai Law
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.
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12
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Phukan B, Mukherjee C, Goswami U, Sarmah A, Mukherjee S, Sahoo SK, Moi SC. A New Bis(aquated) High Relaxivity Mn(II) Complex as an Alternative to Gd(III)-Based MRI Contrast Agent. Inorg Chem 2018; 57:2631-2638. [PMID: 29424537 DOI: 10.1021/acs.inorgchem.7b03039] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Disclosed here are a piperazine, a pyridine, and two carboxylate groups containing pentadentate ligand H2pmpa and its corresponding water-soluble Mn(II) complex (1). DFT-based structural optimization implied that the complex had pentagonal bipyramidal geometry where the axial positions were occupied by two water molecules, and the equatorial plane was constituted by the ligand ON3O donor set. Thus, a bis(aquated) disc-like Mn(II) complex has been synthesized. The complex showed higher stability compared with Mn(II)-EDTA complex [log KMnL = 14.29(3)] and showed a very high r1 relaxivity value of 5.88 mM-1 s-1 at 1.41 T, 25 °C, and pH = 7.4. The relaxivity value remained almost unaffected by the pH of the medium in the range of 6-10. Although the presence of 200 equiv of fluoride and bicarbonate anions did not affect the relaxivity value appreciably, an increase in the value was noticed in the presence of phosphate anion due to slow tumbling of the complex. Cell viability measurements, as well as phantom MR images using clinical MRI imager, consolidated the possible candidature of complex 1 as a positive contrast agent.
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Affiliation(s)
- Bedika Phukan
- Department of Chemistry , Indian Institute of Technology Guwahati , Guwahati 781039 , Assam , India
| | - Chandan Mukherjee
- Department of Chemistry , Indian Institute of Technology Guwahati , Guwahati 781039 , Assam , India
| | - Upashi Goswami
- Centre for Nanotechnology , Indian Institute of Technology Guwahati , Guwahati 781039 , Assam , India
| | - Amrit Sarmah
- Department of Molecular Modelling , Institute of Organic Chemistry and Biochemistry ASCR , Flemingovo nám. 2 , CZ-166 10 Prague 6 , Czech Republic
| | - Subhajit Mukherjee
- Department of Chemistry , National Institute of Technology , Durgapur 713209 , West Bengal , India
| | - Suban K Sahoo
- Department of Applied Chemistry , S.V. National Institute of Technology , Surat 395007 , Gujarat , India
| | - Sankar Ch Moi
- Department of Chemistry , National Institute of Technology , Durgapur 713209 , West Bengal , India
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Abstract
MRI contrast is often enhanced using a contrast agent. Gd3+-complexes are the most widely used metallic MRI agents, and several types of Gd3+-based contrast agents (GBCAs) have been developed. Furthermore, recent advances in MRI technology have, in part, been driven by the development of new GBCAs. However, when designing new functional GBCAs in a small-molecular-weight or nanoparticle form for possible clinical applications, their functions are often compromised by poor pharmacokinetics and possible toxicity. Although great progress must be made in overcoming these limitations and many challenges remain, new functional GBCAs with either small-molecular-weight or nanoparticle forms offer an exciting opportunity for use in precision medicine.
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14
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Hydration number: crucial role in nuclear magnetic relaxivity of Gd(III) chelate-based nanoparticles. Sci Rep 2017; 7:14010. [PMID: 29070882 PMCID: PMC5656664 DOI: 10.1038/s41598-017-14409-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/09/2017] [Indexed: 12/28/2022] Open
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-1s-1 and r2 = 3.95 mM-1s-1), while these values tend to increase substantially (r1 = 12.41 mM-1s-1, r2 = 14.36 mM-1s-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.
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15
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Sevrain CM, Berchel M, Couthon H, Jaffrès PA. Phosphonic acid: preparation and applications. Beilstein J Org Chem 2017; 13:2186-2213. [PMID: 29114326 PMCID: PMC5669239 DOI: 10.3762/bjoc.13.219] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/19/2017] [Indexed: 12/26/2022] Open
Abstract
The phosphonic acid functional group, which is characterized by a phosphorus atom bonded to three oxygen atoms (two hydroxy groups and one P=O double bond) and one carbon atom, is employed for many applications due to its structural analogy with the phosphate moiety or to its coordination or supramolecular properties. Phosphonic acids were used for their bioactive properties (drug, pro-drug), for bone targeting, for the design of supramolecular or hybrid materials, for the functionalization of surfaces, for analytical purposes, for medical imaging or as phosphoantigen. These applications are covering a large panel of research fields including chemistry, biology and physics thus making the synthesis of phosphonic acids a determinant question for numerous research projects. This review gives, first, an overview of the different fields of application of phosphonic acids that are illustrated with studies mainly selected over the last 20 years. Further, this review reports the different methods that can be used for the synthesis of phosphonic acids from dialkyl or diaryl phosphonate, from dichlorophosphine or dichlorophosphine oxide, from phosphonodiamide, or by oxidation of phosphinic acid. Direct methods that make use of phosphorous acid (H3PO3) and that produce a phosphonic acid functional group simultaneously to the formation of the P-C bond, are also surveyed. Among all these methods, the dealkylation of dialkyl phosphonates under either acidic conditions (HCl) or using the McKenna procedure (a two-step reaction that makes use of bromotrimethylsilane followed by methanolysis) constitute the best methods to prepare phosphonic acids.
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Affiliation(s)
- Charlotte M Sevrain
- CEMCA UMR CNRS 6521, Université de Brest, IBSAM. 6 Avenue Victor Le Gorgeu, 29238 Brest, France
| | - Mathieu Berchel
- CEMCA UMR CNRS 6521, Université de Brest, IBSAM. 6 Avenue Victor Le Gorgeu, 29238 Brest, France
| | - Hélène Couthon
- CEMCA UMR CNRS 6521, Université de Brest, IBSAM. 6 Avenue Victor Le Gorgeu, 29238 Brest, France
| | - Paul-Alain Jaffrès
- CEMCA UMR CNRS 6521, Université de Brest, IBSAM. 6 Avenue Victor Le Gorgeu, 29238 Brest, France
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16
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Wang L, Lin H, Ma L, Sun C, Huang J, Li A, Zhao T, Chen Z, Gao J. Geometrical confinement directed albumin-based nanoprobes as enhanced T1 contrast agents for tumor imaging. J Mater Chem B 2017; 5:8004-8012. [DOI: 10.1039/c7tb02005h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We report a facile strategy to assemble geometrically confined albumin-based nanoparticles as T1 contrast agents for sensitive tumor imaging.
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Affiliation(s)
- Lirong Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
| | - Hongyu Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
| | - Lengceng Ma
- Department of Electronic Science and Fujian Key Laboratory of Plasma and Magnetic Resonance
- Xiamen University
- Xiamen 361005
- China
| | - Chengjie Sun
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
| | - Jiaqi Huang
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
| | - Ao Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
| | - Tian Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
| | - Zhong Chen
- Department of Electronic Science and Fujian Key Laboratory of Plasma and Magnetic Resonance
- Xiamen University
- Xiamen 361005
- China
| | - Jinhao Gao
- State Key Laboratory of Physical Chemistry of Solid Surfaces
- The MOE Laboratory of Spectrochemical Analysis & Instrumentation
- The Key Laboratory for Chemical Biology of Fujian Province, and iChEM
- College of Chemistry and Chemical Engineering
- Xiamen University
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17
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Souri N, Tian P, Lecointre A, Lemaire Z, Chafaa S, Strub JM, Cianférani S, Elhabiri M, Platas-Iglesias C, Charbonnière LJ. Step by Step Assembly of Polynuclear Lanthanide Complexes with a Phosphonated Bipyridine Ligand. Inorg Chem 2016; 55:12962-12974. [DOI: 10.1021/acs.inorgchem.6b02414] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nabila Souri
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Institut
Pluridisciplinaire Hubert Curien (IPHC, UMR 7178), CNRS-Université de Strasbourg,, ECPM, 25, rue Becquerel, 67087 Strasbourg Cedex, France
- Laboratoire d’électrochimie des Matériaux Moléculaires
et des Complexes, LEMMC, Faculté de Technologie, Université de Sétif-1, Sétif, Algeria
| | - Pingping Tian
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Institut
Pluridisciplinaire Hubert Curien (IPHC, UMR 7178), CNRS-Université de Strasbourg,, ECPM, 25, rue Becquerel, 67087 Strasbourg Cedex, France
| | - Alexandre Lecointre
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Institut
Pluridisciplinaire Hubert Curien (IPHC, UMR 7178), CNRS-Université de Strasbourg,, ECPM, 25, rue Becquerel, 67087 Strasbourg Cedex, France
| | - Zoé Lemaire
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Institut
Pluridisciplinaire Hubert Curien (IPHC, UMR 7178), CNRS-Université de Strasbourg,, ECPM, 25, rue Becquerel, 67087 Strasbourg Cedex, France
| | - Salah Chafaa
- Laboratoire d’électrochimie des Matériaux Moléculaires
et des Complexes, LEMMC, Faculté de Technologie, Université de Sétif-1, Sétif, Algeria
| | - Jean-Marc Strub
- Laboratoire
de Spectrométrie de Masse Bio-Organique, IPHC, UMR 7178, CNRS-Université de Strasbourg, ECPM, 25, rue Becquerel, 67087 Strasbourg, France
| | - Sarah Cianférani
- Laboratoire
de Spectrométrie de Masse Bio-Organique, IPHC, UMR 7178, CNRS-Université de Strasbourg, ECPM, 25, rue Becquerel, 67087 Strasbourg, France
| | - Mourad Elhabiri
- Laboratoire de Chimie Bioorganique et Médicinale, UMR 7509, CNRS-Université de Strasbourg, ECPM, 25, rue Becquerel, 67087 Strasbourg Cedex 02, France
| | - Carlos Platas-Iglesias
- Universidade da Coruña, Centro de Investigacións
Científicas Avanzadas (CICA) and Departamento de Química
Fundamental, Facultade de Ciencias, 15071 A Coruña, Galicia, Spain
| | - Loïc J. Charbonnière
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Institut
Pluridisciplinaire Hubert Curien (IPHC, UMR 7178), CNRS-Université de Strasbourg,, ECPM, 25, rue Becquerel, 67087 Strasbourg Cedex, France
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18
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Longo DL, Arena F, Consolino L, Minazzi P, Geninatti-Crich S, Giovenzana GB, Aime S. Gd-AAZTA-MADEC, an improved blood pool agent for DCE-MRI studies on mice on 1 T scanners. Biomaterials 2015; 75:47-57. [PMID: 26480471 DOI: 10.1016/j.biomaterials.2015.10.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 09/30/2015] [Accepted: 10/05/2015] [Indexed: 10/22/2022]
Abstract
A novel MRI blood-pool contrast agent (Gd-AAZTA-MADEC) has been compared with established blood pool agents for tumor contrast enhanced images and angiography. Synthesis, relaxometric properties, albumin binding affinity and pharmacokinetic profiles are reported. For in vivo studies, angiographic images and tumor contrast enhanced images were acquired on mice with benchtop 1T-MRI scanners and compared with MS-325, B22956/1 and B25716/1. The design of this contrast agent involved the elongation of the spacer between the targeting deoxycholic acid moiety and the Gd-AAZTA imaging reporting unit that drastically changed either the binding affinity to albumin (KA(HSA) = 8.3 × 10(5) M(-1)) and the hydration state of the Gd ion (q = 2) in comparison to the recently reported B25716/1. The very markedly high binding affinity towards mouse and human serum albumins resulted in peculiar pharmacokinetics and relaxometric properties. The NMRD profiles clearly indicated that maximum efficiency is attainable at magnetic field strength of 1 T. In vivo studies showed high enhancement of the vasculature and a prolonged accumulation inside tumor. The herein reported pre-clinical imaging studies show that a great benefit arises from the combination of a benchtop MRI scanner operating at 1 T and the albumin-binding Gd-AAZTA-MADEC complex, for pursuing enhanced angiography and improved characterization of tumor vascular microenvironment.
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Affiliation(s)
- Dario Livio Longo
- Istituto di Biostrutture e Bioimmagini (CNR) c/o Molecular Biotechnology Center, Via Nizza 52, 10126, Torino, Italy; Molecular Imaging Center, University of Torino, Via Nizza 52, 10126, Torino, Italy.
| | - Francesca Arena
- Molecular Imaging Center, University of Torino, Via Nizza 52, 10126, Torino, Italy; Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Torino, Italy
| | - Lorena Consolino
- Molecular Imaging Center, University of Torino, Via Nizza 52, 10126, Torino, Italy; Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Torino, Italy; CAGE Chemicals Srl, Via Bovio 6, 28100, Novara, Italy
| | - Paolo Minazzi
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale "A. Avogadro" Largo Donegani 2/3, 28100, Novara, Italy; CAGE Chemicals Srl, Via Bovio 6, 28100, Novara, Italy
| | - Simonetta Geninatti-Crich
- Molecular Imaging Center, University of Torino, Via Nizza 52, 10126, Torino, Italy; Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Torino, Italy
| | - Giovanni Battista Giovenzana
- Dipartimento di Scienze del Farmaco, Università del Piemonte Orientale "A. Avogadro" Largo Donegani 2/3, 28100, Novara, Italy; CAGE Chemicals Srl, Via Bovio 6, 28100, Novara, Italy
| | - Silvio Aime
- Istituto di Biostrutture e Bioimmagini (CNR) c/o Molecular Biotechnology Center, Via Nizza 52, 10126, Torino, Italy; Molecular Imaging Center, University of Torino, Via Nizza 52, 10126, Torino, Italy; Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126, Torino, Italy
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19
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Abstract
This perspective outlines strategies towards the development of MR imaging probes that our lab has explored over the last 15 years. Namely, we discuss methods to enhance the signal generating capacity of MR probes and how to achieve tissue specificity through protein targeting or probe activation within the tissue microenvironment.
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Affiliation(s)
- Eszter Boros
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Eric M Gale
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Peter Caravan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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20
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Elhabiri M, Abada S, Sy M, Nonat A, Choquet P, Esteban-Gómez D, Cassino C, Platas-Iglesias C, Botta M, Charbonnière LJ. Importance of Outer-Sphere and Aggregation Phenomena in the Relaxation Properties of Phosphonated Gadolinium Complexes with Potential Applications as MRI Contrast Agents. Chemistry 2015; 21:6535-46. [DOI: 10.1002/chem.201500155] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 11/10/2022]
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21
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Boros E, Caravan. P. Probing the structure-relaxivity relationship of bis-hydrated Gd(DOTAla) derivatives. Inorg Chem 2015; 54:2403-10. [PMID: 25693053 PMCID: PMC4758459 DOI: 10.1021/ic503035f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two structural isomers of the heptadentate chelator DO3Ala were synthesized, with carboxymethyl groups at either the 1,4- or 1,7-positions of the cyclen macrocycle. To interrogate the relaxivity under different rotatational dynamics regimes, the pendant primary amine was coupled to ibuprofen to enable binding to serum albumin. These chelators 6a and 6b form bis(aqua) ternary complexes with Gd(III) or Tb(III) as estimated from relaxivity measurements or luminescence lifetime measurements in water. The relaxivity of [Gd(6a)(H2O)2] and [Gd(6b)(H2O)2] was measured in the presence and absence of coordinating anions prevalent in vivo such as phosphate, lactate, and bicarbonate and compared with data attained for the q = 2 complex [Gd(DO3A)(H2O)2]. We found that relaxivity was reduced through formation of ternary complexes with lactate and bicarbonate, albeit to a lesser degree then the relaxivity of Gd(DO3A). In the presence of 100-fold excess phosphate, relaxivity was slightly increased and typical for q = 2 complexes of this size (8.3 mM(-1) s(-1) and 9.5 mM(-1) s(-1), respectively, at 37 °C, 60 MHz). Relaxivity for the complexes in the presence of HSA corresponded well to relaxivity obtained for complexes with reduced access for inner-sphere water (13.5 and 12.7 mM(-1) s(-1) at 37 °C, 60 MHz). Mean water residency time at 37 °C was determined using temperature-dependent (17)O-T2 measurements at 11.7 T and calculated to be (310)τM = 23 ± 1 ns for both structural isomers. Kinetic inertness under forcing conditions (pH 3, competing DTPA ligand) was found to be comparable to [Gd(DO3A)(H2O)]. Overall, we found that the replacement of one of the acetate arms of DO3A with an amino-propionate arm does not significantly alter the relaxometric and kinetic inertness properties of the corresponding Gd complexes; however, it does provide access to easily functionalizable q = 2 derivatives.
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Affiliation(s)
- Eszter Boros
- The Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, Massachusetts 02129, United States
| | - Peter Caravan.
- The Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, Massachusetts 02129, United States
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