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Jian Y, Mo G, Xu W, Liu Y, Zhang Z, Ding Y, Gao R, Xu J, Zhu J, Shu K, Yan Z, Carniato F, Platas-Iglesias C, Ye F, Botta M, Dai L. Chiral Pyclen-Based Heptadentate Chelates as Highly Stable MRI Contrast Agents. Inorg Chem 2024; 63:8462-8475. [PMID: 38642052 DOI: 10.1021/acs.inorgchem.4c01028] [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: 04/22/2024]
Abstract
In recent years, pyclen-based complexes have attracted a great deal of interest as magnetic resonance imaging (MRI) contrast agents (CAs) and luminescent materials, as well as radiopharmaceuticals. Remarkably, gadopiclenol, a Gd(III) bishydrated complex featuring a pyclen-based heptadentate ligand, received approval as a novel contrast agent for clinical MRI application in 2022. To maximize stability and efficiency, two novel chiral pyclen-based chelators and their complexes were developed in this study. Gd-X-PCTA-2 showed significant enhancements in both thermodynamic and kinetic stabilities compared to those of the achiral parent derivative Gd-PCTA. 1H NMRD profiles reveal that both chiral gadolinium complexes (Gd-X-PCTA-1 and Gd-X-PCTA-2) have a higher relaxivity than Gd-PCTA, while variable-temperature 17O NMR studies show that the two inner-sphere water molecules have distinct residence times τMa and τMb. Furthermore, in vivo imaging demonstrates that Gd-X-PCTA-2 enhances the signal in the heart and kidneys of the mice, and the chiral Gd complexes exhibit the ability to distinguish between tumors and normal tissues in a 4T1 mouse model more efficiently than that of the clinical agent gadobutrol. Biodistribution studies show that Gd-PCTA and Gd-X-PCTA-2 are primarily cleared by a renal pathway, with 24 h residues of Gd-X-PCTA-2 in the liver and kidney being lower than those of Gd-PCTA.
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Affiliation(s)
- Yong Jian
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325035
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Gengshen Mo
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Weiyuan Xu
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Yao Liu
- Sichuan Key Laboratory of Medical Imaging, School of Pharmacy and Nanchong Key laboratory of MRI Contrast Agent, North Sichuan Medical College, Nanchong, People's Republic of China 637000
| | - Zhichao Zhang
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Yinghui Ding
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Ruonan Gao
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Jiao Xu
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Jiang Zhu
- Sichuan Key Laboratory of Medical Imaging, School of Pharmacy and Nanchong Key laboratory of MRI Contrast Agent, North Sichuan Medical College, Nanchong, People's Republic of China 637000
| | - Kun Shu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325027
| | - Zhihan Yan
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325027
| | - Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, Italy 15121
| | - Carlos Platas-Iglesias
- Departamento de Química Fundamental, Facultade de Ciencias, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, A Coruña, Spain 15008
| | - Fangfu Ye
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325035
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, Viale T. Michel 11, Alessandria, Italy 15121
| | - Lixiong Dai
- Joint Centre of Translational Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People's Republic of China 325035
- Joint Centre of Translational Medicine, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, People's Republic of China 325000
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2
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Uzal-Varela R, Rodríguez-Rodríguez A, Lalli D, Valencia L, Maneiro M, Botta M, Iglesias E, Esteban-Gómez D, Angelovski G, Platas-Iglesias C. Endeavor toward Redox-Responsive Transition Metal Contrast Agents Based on the Cross-Bridge Cyclam Platform. Inorg Chem 2024; 63:1575-1588. [PMID: 38198518 PMCID: PMC10806912 DOI: 10.1021/acs.inorgchem.3c03486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024]
Abstract
We present the synthesis and characterization of a series of Mn(III), Co(III), and Ni(II) complexes with cross-bridge cyclam derivatives (CB-cyclam = 1,4,8,11-tetraazabicyclo[6.6.2]hexadecane) containing acetamide or acetic acid pendant arms. The X-ray structures of [Ni(CB-TE2AM)]Cl2·2H2O and [Mn(CB-TE1AM)(OH)](PF6)2 evidence the octahedral coordination of the ligands around the Ni(II) and Mn(III) metal ions, with a terminal hydroxide ligand being coordinated to Mn(III). Cyclic voltammetry studies on solutions of the [Mn(CB-TE1AM)(OH)]2+ and [Mn(CB-TE1A)(OH)]+ complexes (0.15 M NaCl) show an intricate redox behavior with waves due to the MnIII/MnIV and MnII/MnIII pairs. The Co(III) and Ni(II) complexes with CB-TE2A and CB-TE2AM show quasi-reversible features due to the CoIII/CoII or NiII/NiIII pairs. The [Co(CB-TE2AM)]3+ complex is readily reduced by dithionite in aqueous solution, as evidenced by 1H NMR studies, but does not react with ascorbate. The [Mn(CB-TE1A)(OH)]+ complex is however reduced very quickly by ascorbate following a simple kinetic scheme (k0 = k1[AH-], where [AH-] is the ascorbate concentration and k1 = 628 ± 7 M-1 s-1). The reduction of the Mn(III) complex to Mn(II) by ascorbate provokes complex dissociation, as demonstrated by 1H nuclear magnetic relaxation dispersion studies. The [Ni(CB-TE2AM)]2+ complex shows significant chemical exchange saturation transfer effects upon saturation of the amide proton signals at 71 and 3 ppm with respect to the bulk water signal.
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Affiliation(s)
- Rocío Uzal-Varela
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña 15071, Galicia, Spain
| | - Aurora Rodríguez-Rodríguez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña 15071, Galicia, Spain
| | - Daniela Lalli
- Dipartimento
di Scienze e Innovazione Tecnologica, Magnetic Resonance Platform
(PRISMA-UPO), Universitá del Piemonte
Orientale, Viale T. Michel
11, Alessandria 15121, Italy
| | - Laura Valencia
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende 36310, Pontevedra, Spain
| | - Marcelino Maneiro
- Departamento
de Química Inorgánica, Facultade de Ciencias, Campus
Terra, Universidade de Santiago de Compostela, Lugo 27002, Galicia, Spain
| | - Mauro Botta
- Dipartimento
di Scienze e Innovazione Tecnologica, Magnetic Resonance Platform
(PRISMA-UPO), Universitá del Piemonte
Orientale, Viale T. Michel
11, Alessandria 15121, Italy
| | - Emilia Iglesias
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña 15071, Galicia, Spain
| | - David Esteban-Gómez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña 15071, Galicia, Spain
| | - Goran Angelovski
- Laboratory
of Molecular and Cellular Neuroimaging, International Center for Primate
Brain Research (ICPBR), Center for Excellence in Brain Science and
Intelligence Technology (CEBSIT), Chinese
Academy of Sciences (CAS), Shanghai 201602, PR China
| | - Carlos Platas-Iglesias
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña 15071, Galicia, Spain
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3
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Panda SK, Rai A, Singh AK. Study of paraCEST response on six-coordinated Co(II) and Ni(II) complexes of a pyridine-tetraamide-based ligand. Dalton Trans 2023. [PMID: 38009007 DOI: 10.1039/d3dt02283h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2023]
Abstract
This study highlights the successful synthesis of a potential ligand, 2,2',2'',2'''-((pyridine-2,6-diylbis(methylene))bis(azanetriyl))tetraacetamide (PATA), along with its corresponding Co(II) and Ni(II) complexes for paraCEST-based agents. X-ray diffraction data confirmed that both the complexes are six coordinated with distorted octahedral geometries, but only the [Co(PATA)]2+ complex has a good structural feature to show paraCEST activity. After a thorough characterization of the ligand and both of its complexes, various studies, including solution-state magnetic properties, redox properties, temperature, and pH variation studies, were carried out. [Co(PATA)]2+ remained inert in the presence of competing ions, under acidic conditions, at high temperatures, and in the physiological pH range. The paraCEST response of [Co(PATA)]2+ has been measured in the presence of HEPES buffer medium, and a high paraCEST feature was discovered at both 37 and 25 °C. The pH variation paraCEST studies were carried out and the exchange rate constant of the probe at 37 and 25 °C was also determined. However, due to the fast exchange of water protons, the [Ni(PATA)(OH2)]2+ complex remained inactive in the CEST process.
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Affiliation(s)
- Suvam Kumar Panda
- Indian Institute of Technology Bhubaneswar, Khordha, Odisha, 752050, India.
| | - Ankit Rai
- Indian Institute of Technology Bhubaneswar, Khordha, Odisha, 752050, India.
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Harriswangler C, Lucio-Martínez F, Godec L, Soro LK, Fernández-Fariña S, Valencia L, Rodríguez-Rodríguez A, Esteban-Gómez D, Charbonnière LJ, Platas-Iglesias C. Effect of Magnetic Anisotropy on the 1H NMR Paramagnetic Shifts and Relaxation Rates of Small Dysprosium(III) Complexes. Inorg Chem 2023; 62:14326-14338. [PMID: 37602400 PMCID: PMC10481378 DOI: 10.1021/acs.inorgchem.3c01959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Indexed: 08/22/2023]
Abstract
We present a detailed analysis of the 1H NMR chemical shifts and transverse relaxation rates of three small Dy(III) complexes having different symmetries (C3, D2 or C2). The complexes show sizeable emission in the visible region due to 4F9/2 → 6HJ transitions (J = 15/2 to 11/2). Additionally, NIR emission is observed at ca. 850 (4F9/2 → 6H7/2), 930 (4F9/2 → 6H5/2), 1010 (4F9/2 → 6F9/2), and 1175 nm (4F9/2 → 6F7/2). Emission quantum yields of 1-2% were determined in aqueous solutions. The emission lifetimes indicate that no water molecules are present in the inner coordination sphere of Dy(III), which in the case of [Dy(CB-TE2PA)]+ was confirmed through the X-ray crystal structure. The 1H NMR paramagnetic shifts induced by Dy(III) were found to be dominated by the pseudocontact mechanism, though, for some protons, contact shifts are not negligible. The analysis of the pseudocontact shifts provided the magnetic susceptibility tensors of the three complexes, which were also investigated using CASSCF calculations. The transverse 1H relaxation data follow a good linear correlation with 1/r6, where r is the distance between the Dy(III) ion and the observed proton. This indicates that magnetic anisotropy is not significantly affecting the relaxation of 1H nuclei in the family of complexes investigated here.
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Affiliation(s)
- Charlene Harriswangler
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Fátima Lucio-Martínez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Léna Godec
- Equipe
de Synthèse Pour l′Analyse (SynPA), Institut Pluridisciplinaire
Hubert Curien (IPHC), UMR 7178, CNRS, Université
de Strasbourg, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex, France
| | - Lohona Kevin Soro
- Equipe
de Synthèse Pour l′Analyse (SynPA), Institut Pluridisciplinaire
Hubert Curien (IPHC), UMR 7178, CNRS, Université
de Strasbourg, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex, France
| | - Sandra Fernández-Fariña
- Departamento
de Química Inorgánica, Facultade de Química,
Campus Vida, Universidade de Santiago de
Compostela, 15782 Santiago de Compostela, Spain
| | - Laura Valencia
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
| | - Aurora Rodríguez-Rodríguez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - David Esteban-Gómez
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
| | - Loïc J. Charbonnière
- Equipe
de Synthèse Pour l′Analyse (SynPA), Institut Pluridisciplinaire
Hubert Curien (IPHC), UMR 7178, CNRS, Université
de Strasbourg, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex, France
| | - Carlos Platas-Iglesias
- Centro
Interdisciplinar de Química e Bioloxía (CICA) and Departamento
de Química, Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Galicia, Spain
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5
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Longo DL, Carella A, Corrado A, Pirotta E, Mohanta Z, Singh A, Stabinska J, Liu G, McMahon MT. A snapshot of the vast array of diamagnetic CEST MRI contrast agents. NMR IN BIOMEDICINE 2023; 36:e4715. [PMID: 35187749 PMCID: PMC9724179 DOI: 10.1002/nbm.4715] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 05/11/2023]
Abstract
Since the inception of CEST MRI in the 1990s, a number of compounds have been identified as suitable for generating contrast, including paramagnetic lanthanide complexes, hyperpolarized atom cages and, most interesting, diamagnetic compounds. In the past two decades, there has been a major emphasis in this field on the identification and application of diamagnetic compounds that have suitable biosafety profiles for usage in medical applications. Even in the past five years there has been a tremendous growth in their numbers, with more and more emphasis being placed on finding those that can be ultimately used for patient studies on clinical 3 T scanners. At this point, a number of endogenous compounds present in tissue have been identified, and also natural and synthetic organic compounds that can be administered to highlight pathology via CEST imaging. Here we will provide a very extensive snapshot of the types of diamagnetic compound that can generate CEST MRI contrast, together with guidance on their utility on typical preclinical and clinical scanners and a review of the applications that might benefit the most from this new technology.
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Affiliation(s)
- Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Antonella Carella
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Alessia Corrado
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Elisa Pirotta
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Zinia Mohanta
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Aruna Singh
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Julia Stabinska
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Guanshu Liu
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael T. McMahon
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Bo S, Zhang D, Ma M, Mo X, Stabinska J, McMahon MT, Shi C, Luo L. Acyl Hydrazides and Acyl Hydrazones as High-Performance Chemical Exchange Saturation Transfer MRI Contrast Agents. Pharmaceuticals (Basel) 2023; 16:ph16050639. [PMID: 37242423 DOI: 10.3390/ph16050639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/17/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Chemical exchange saturation transfer (CEST) MRI is a versatile molecular imaging approach that holds great promise for clinical translation. A number of compounds have been identified as suitable for performing CEST MRI, including paramagnetic CEST (paraCEST) agents and diamagnetic CEST (diaCEST) agents. DiaCEST agents are very attractive because of their excellent biocompatibility and potential for biodegradation, such as glucose, glycogen, glutamate, creatine, nucleic acids, et al. However, the sensitivity of most diaCEST agents is limited because of small chemical shifts (1.0-4.0 ppm) from water. To expand the catalog of diaCEST agents with larger chemical shifts, herein, we have systematically investigated the CEST properties of acyl hydrazides with different substitutions, including aromatic and aliphatic substituents. We have tuned the labile proton chemical shifts from 2.8-5.0 ppm from water while exchange rates varied from ~680 to 2340 s-1 at pH 7.2, which allows strong CEST contrast on scanners down to B0 = 3 T. One acyl hydrazide, adipic acid dihydrazide (ADH), was tested on a mouse model of breast cancer and showed nice contrast in the tumor region. We also prepared a derivative, acyl hydrazone, which showed the furthest shifted labile proton (6.4 ppm from water) and excellent contrast properties. Overall, our study expands the catalog of diaCEST agents and their application in cancer diagnosis.
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Affiliation(s)
- Shaowei Bo
- Department of Medical Imaging, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou 510317, China
| | - Dong Zhang
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China
| | - Mengjie Ma
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China
| | - Xukai Mo
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China
| | - Julia Stabinska
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21287, USA
| | - Michael T McMahon
- The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21287, USA
| | - Changzheng Shi
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China
| | - Liangping Luo
- Department of Medical Imaging, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou 510317, China
- Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China
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7
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Zhao Y, Zu Z, Xu J, Gore JC, Does MD, Li J, Gochberg DF. Mapping pH using stimulated echoes formed via chemical exchange. Magn Reson Imaging 2022; 92:100-107. [PMID: 35764217 DOI: 10.1016/j.mri.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/10/2022] [Accepted: 06/22/2022] [Indexed: 12/09/2022]
Abstract
PURPOSE RACETE (refocused acquisition of chemical exchange transferred excitations) is a recently developed approach to imaging solute exchange with water. However, it lacks biophysical specificity, as it is sensitive to exchange rates, relaxation rates, solute concentration, and macromolecular content. We modified this sequence and developed a protocol and corresponding metric with specific sensitivity to the solute exchange rate and hence a means for mapping pH. THEORY AND METHODS RACETE splits the two gradients traditionally used in a stimulated-echo sequence into one applied after exciting solutes and one applied after exciting water, hence requiring exchange for echo formation. In this work, we leverage the dependence of the stimulated-echo signal on the exchange process. By preserving the total irradiation power and using a ratio metric, the other signal dependencies cancel, leaving a specific measure of exchange rate. Additionally, artifacts due to off-resonance excitation of water are addressed using a phase cancelling approach; and a gradient-echo imaging sequence with a variable flip angle excitation is tailored for a fast read-out of RECETE prepared signals. This method is validated using numerical simulations and salicylic acid phantom experiments at 9.4 T. RESULTS Numerical simulations and phantom experiments demonstrate that the ratio-metric is a single-variable function of exchange rate with extremely low dependence on confounding factors. Additionally, artifacts due to direct water excitation are removed and robustness to B0 and B1 inhomogeneities is demonstrated. CONCLUSION The proposed method can be used for fast pH mapping with robustness against the confounding effects that widely exist in other methods.
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Affiliation(s)
- Yu Zhao
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA; Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
| | - Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Junzhong Xu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mark D Does
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jianqi Li
- Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
| | - Daniel F Gochberg
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA.
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8
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Pérez-Lourido P, Madarasi E, Antal F, Esteban-Gómez D, Wang G, Angelovski G, Platas-Iglesias C, Tircsó G, Valencia L. Stable and inert macrocyclic cobalt(II) and nickel(II) complexes with paraCEST response. Dalton Trans 2022; 51:1580-1593. [PMID: 34991150 DOI: 10.1039/d1dt03217h] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We report the synthesis of the macrocyclic ligands 3,9-PC2AMH (2,2'-(3,6,9-triaza-1(2,6)-pyridinacyclodecaphane-3,9-diyl)diacetamide) and 3,9-PC2AMtBu (2,2'-(3,6,9-triaza-1(2,6)-pyridinacyclodecaphane-3,9-diyl)bis(N-tert-butyl)acetamide) which contain a pyclen platform functionalized with acetamide or tert-butylacetamide pendant arms at positions 3 and 9 of the macrocyclic unit. The corresponding Co(II) and Ni(II) complexes were prepared, isolated and characterised as potential paramagnetic chemical exchange saturation transfer (paraCEST) agents. The X-ray structures of the Ni(II) complexes reveal six-coordination of the ligands to the metal ion. The Co(II) complex with 3,9-PC2AMtBu shows a similar six-coordinate structure in the solid state, while the Co(II) complex with 3,9-PC2AMH contains a seven-coordinate metal ion, seventh coordination being completed by the presence of an inner-sphere water molecule. The structure of the Co(II) complexes was investigated using 1H NMR spectroscopy and computational methods. The complexes present a seven-coordinate structure in solution, as demonstrated by the analysis of the paramagnetic shifts using density functional theory. Ligand protonation constants and stability constants of the complexes with 3,9-PC2AMH were determined using potentiometric titrations (I = 0,15 M NaCl). The Co(II) complex was found to be more stable than the Ni(II) analogue (log KCoL = 14.46(5) and log KNiL = 13.15(3)). However, the Ni(II) and Co(II) complexes display similar rate constants characterizing the proton-assisted dissociation mechanism. The presence of highly shifted 1H NMR signals due to the amide protons in slow exchange with bulk water results in sizeable CEST signals, which are observed at +67 and +15 ppm for the Co(II) complex with 3,9-PC2AMH and +42 and +7 ppm for the Ni(II) analogue at 25 °C.
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Affiliation(s)
- Paulo Pérez-Lourido
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain.
| | - Enikő Madarasi
- Doctoral School of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4010, Debrecen, Egyetem tér 1, Hungary
| | - Fanni Antal
- Doctoral School of Chemistry, Faculty of Science and Technology, University of Debrecen, H-4010, Debrecen, Egyetem tér 1, Hungary
| | - David Esteban-Gómez
- Universidade da Coruña, Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, 15071, A Coruña, Galicia, Spain.
| | - Gaoji Wang
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - Goran Angelovski
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.,Laboratory of Molecular and Cellular Neuroimaging, International Center for Primate Brain Research (ICPBR), Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Chinese Academy of Sciences (CAS), 20031 Shanghai, PR China
| | - Carlos Platas-Iglesias
- Universidade da Coruña, Centro de Investigacións Científicas Avanzadas (CICA) and Departamento de Química, Facultade de Ciencias, 15071, A Coruña, Galicia, Spain.
| | - Gyula Tircsó
- Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, H-4010, Debrecen, Egyetem tér 1, Hungary
| | - Laura Valencia
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain.
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9
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Pandey S, Keerthana AC, Madhulika S, Prasad P, Peruncheralathan S, Ghosh A. Hydrothermal treatment as a means of improving the solubility and enhancing the diaCEST MRI contrast efficiency. NEW J CHEM 2022. [DOI: 10.1039/d2nj02529a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon dot formation through the hydrothermal treatment of amino-thioamide improves the diaCEST contrast efficiency.
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Affiliation(s)
- Shalini Pandey
- School of Chemical Sciences, National Institute of Science Education and Research(NISER), HBNI, Jatni, Khurda, Bhubaneswar, 752050, Odisha, India
| | - Anil C. Keerthana
- School of Chemical Sciences, National Institute of Science Education and Research(NISER), HBNI, Jatni, Khurda, Bhubaneswar, 752050, Odisha, India
| | - Swati Madhulika
- Chromatin and Epigenetic group, Institute of Life Sciences, Bhubaneswar, 751023, Odisha, India
| | - Punit Prasad
- Chromatin and Epigenetic group, Institute of Life Sciences, Bhubaneswar, 751023, Odisha, India
| | - S. Peruncheralathan
- School of Chemical Sciences, National Institute of Science Education and Research(NISER), HBNI, Jatni, Khurda, Bhubaneswar, 752050, Odisha, India
| | - Arindam Ghosh
- School of Chemical Sciences, National Institute of Science Education and Research(NISER), HBNI, Jatni, Khurda, Bhubaneswar, 752050, Odisha, India
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10
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Castro G, Wang G, Gambino T, Esteban-Gómez D, Valencia L, Angelovski G, Platas-Iglesias C, Pérez-Lourido P. Lanthanide(III) Complexes Based on an 18-Membered Macrocycle Containing Acetamide Pendants. Structural Characterization and paraCEST Properties. Inorg Chem 2021; 60:1902-1914. [PMID: 33471999 PMCID: PMC8929667 DOI: 10.1021/acs.inorgchem.0c03385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a detailed investigation of the coordination properties of macrocyclic lanthanide complexes containing a 3,6,10,13-tetraaza-1,8(2,6)-dipyridinacyclotetradecaphane scaffold functionalized with four acetamide pendant arms. The X-ray structures of the complexes with the large Ln3+ ions (La and Sm) display 12- and 10-coordinated metal ions, where the coordination sphere is fulfilled by the six N atoms of the macrocycle, the four O atoms of the acetamide pendants, and a bidentate nitrate anion in the La3+ complex. The analogous Yb3+ complex presents, however, a 9-coordinated metal ion because one of the acetamide pendant arms remains uncoordinated. 1H NMR studies indicate that the 10-coordinated form is present in solution throughout the lanthanide series from La to Tb, while the smaller lanthanides form 9-coordinated species. 1H and 89Y NMR studies confirm the presence of this structural change because the two species are present in solution. Analysis of the 1H chemical shifts observed for the Tb3+ complex confirms its D2 symmetry in aqueous solution and evidences a highly rhombic magnetic susceptibility tensor. The acetamide resonances of the Pr3+ and Tb3+ complexes provided sizable paraCEST effects, as demonstrated by the corresponding Z-spectra recorded at different temperatures and studies on tube phantoms recorded at 22 °C.
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Affiliation(s)
- Goretti Castro
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
| | - Gaoji Wang
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - Tanja Gambino
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | - Laura Valencia
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
| | - Goran Angelovski
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.,Laboratory of Molecular and Cellular Neuroimaging, International Center for Primate Brain Research, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 20031 Shanghai, P. R. China
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | - Paulo Pérez-Lourido
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
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11
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Macrocyclic Chelates Bridged by a Diaza-Crown Ether: Towards Multinuclear Bimodal Molecular Imaging Probes. Molecules 2020; 25:molecules25215019. [PMID: 33138207 PMCID: PMC7663075 DOI: 10.3390/molecules25215019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/02/2022] Open
Abstract
Bridged polymacrocyclic ligands featured by structurally different cages offer the possibility of coordinating multiple trivalent lanthanide ions, giving rise to the exploitation of their different physicochemical properties, e.g., multimodal detection for molecular imaging purposes. Intrigued by the complementary properties of optical and MR-based image capturing modalities, we report the synthesis and characterization of the polymetallic Ln(III)-based chelate comprised of two DOTA-amide-based ligands (DOTA—1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) bridged via 1,10-diaza-18-crown-6 (DA18C6) motif. The DOTA-amide moieties and the DA18C6 were used to chelate two Eu(III) ions and one Tb(III) ion, respectively, resulting in a multinuclear heterometallic complex Eu2LTb. The bimetallic complex without Tb(III), Eu2L, displayed a strong paramagnetic chemical exchange saturation transfer (paraCEST) effect. Notably, the luminescence spectra of Eu2LTb featured mixed emission including the characteristic bands of Eu(III) and Tb(III). The advantageous features of the complex Eu2LTb opens new possibilities for the future design of bimodal probes and their potential applicability in CEST MR and optical imaging.
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12
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Connah L, Angelovski G. Solid phase synthesis in the development of magnetic resonance imaging probes. Org Chem Front 2020. [DOI: 10.1039/d0qo00921k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We review the use of the solid phase synthesis methodology for the preparation of diverse and potent MRI probes.
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Affiliation(s)
- Liam Connah
- MR Neuroimaging Agents
- Max Planck Institute for Biological Cybernetics
- Tuebingen
- Germany
| | - Goran Angelovski
- MR Neuroimaging Agents
- Max Planck Institute for Biological Cybernetics
- Tuebingen
- Germany
- Laboratory of Molecular and Cellular Neuroimaging
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