1
|
Brown AM, Butman JL, Lengacher R, Vargo NP, Martin KE, Koller A, Śmiłowicz D, Boros E, Robinson JR. N, N-Alkylation Clarifies the Role of N- and O-Protonated Intermediates in Cyclen-Based 64Cu Radiopharmaceuticals. Inorg Chem 2023; 62:1362-1376. [PMID: 36490364 DOI: 10.1021/acs.inorgchem.2c02907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Radioisotopes of Cu, such as 64Cu and 67Cu, are alluring targets for imaging (e.g., positron emission tomography, PET) and radiotherapeutic applications. Cyclen-based macrocyclic polyaminocarboxylates are one of the most frequently examined bifunctional chelators in vitro and in vivo, including the FDA-approved 64Cu radiopharmaceutical, Cu(DOTATATE) (Detectnet); however, connections between the structure of plausible reactive intermediates and their stability under physiologically relevant conditions remain to be established. In this study, we share the synthesis of a cyclen-based, N,N-alkylated spirocyclic chelate, H2DO3AC4H8, which serves as a model for N-protonation. Our combined experimental (in vitro and in vivo) and computational studies unravel complex pH-dependent speciation and enable side-by-side comparison of N- and O-protonated species of relevant 64Cu radiopharmaceuticals. Our studies suggest that N-protonated species are not inherently unstable species under physiological conditions and demonstrate the potential of N,N-alkylation as a tool for the rational design of future radiopharmaceuticals.
Collapse
Affiliation(s)
- Alexander M Brown
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| | - Jana L Butman
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| | - Raphael Lengacher
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Natasha P Vargo
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| | - Kirsten E Martin
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Angus Koller
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Dariusz Śmiłowicz
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York11794, United States
| | - Jerome R Robinson
- Department of Chemistry, Brown University, Providence, Rhode Island02912, United States
| |
Collapse
|
2
|
Complexes of Bifunctional DO3A-N-(α-amino)propinate Ligands with Mg(II), Ca(II), Cu(II), Zn(II), and Lanthanide(III) Ions: Thermodynamic Stability, Formation and Dissociation Kinetics, and Solution Dynamic NMR Studies. Molecules 2021; 26:molecules26164956. [PMID: 34443543 PMCID: PMC8398831 DOI: 10.3390/molecules26164956] [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: 06/09/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
The thermodynamic, kinetic, and structural properties of Ln3+ complexes with the bifunctional DO3A-ACE4− ligand and its amide derivative DO3A-BACE4− (modelling the case where DO3A-ACE4− ligand binds to vector molecules) have been studied in order to confirm the usefulness of the corresponding Gd3+ complexes as relaxation labels of targeted MRI contrast agents. The stability constants of the Mg2+ and Ca2+ complexes of DO3A-ACE4− and DO3A-BACE4− complexes are lower than for DOTA4− and DO3A3−, while the Zn2+ and Cu2+ complexes have similar and higher stability than for DOTA4− and DO3A3− complexes. The stability constants of the Ln(DO3A-BACE)− complexes increase from Ce3+ to Gd3+ but remain practically constant for the late Ln3+ ions (represented by Yb3+). The stability constants of the Ln(DO3A-ACE)4− and Ln(DO3A-BACE)4− complexes are several orders of magnitude lower than those of the corresponding DOTA4− and DO3A3− complexes. The formation rate of Eu(DO3A-ACE)− is one order of magnitude slower than for Eu(DOTA)−, due to the presence of the protonated amine group, which destabilizes the protonated intermediate complex. This protonated group causes the Ln(DO3A-ACE)− complexes to dissociate several orders of magnitude faster than Ln(DOTA)− and its absence in the Ln(DO3A-BACE)− complexes results in inertness similar to Ln(DOTA)− (as judged by the rate constants of acid assisted dissociation). The 1H NMR spectra of the diamagnetic Y(DO3A-ACE)− and Y(DO3A-BACE)− reflect the slow dynamics at low temperatures of the intramolecular isomerization process between the SA pair of enantiomers, R-Λ(λλλλ) and S-Δ(δδδδ). The conformation of the Cα-substituted pendant arm is different in the two complexes, where the bulky substituent is further away from the macrocyclic ring in Y(DO3A-BACE)− than the amino group in Y(DO3A-ACE)− to minimize steric hindrance. The temperature dependence of the spectra reflects slower ring motions than pendant arms rearrangements in both complexes. Although losing some thermodynamic stability relative to Gd(DOTA)−, Gd(DO3A-BACE)− is still quite inert, indicating the usefulness of the bifunctional DO3A-ACE4− in the design of GBCAs and Ln3+-based tags for protein structural NMR analysis.
Collapse
|
3
|
Baranyai Z, Tircsó G, Rösch F. The Use of the Macrocyclic Chelator DOTA in Radiochemical Separations. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900706] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Zsolt Baranyai
- Bracco Research Centre Bracco Imaging spa Via Ribes 5 10010 Colleretto Giacosa (TO) Italy
| | - Gyula Tircsó
- Department of Physical Chemistry Faculty of Science and Technology University of Debrecen Egyetem tér 1 Debrecen 4032 Hungary
| | - Frank Rösch
- Institute of Nuclear Chemistry Johannes Gutenberg‐University of Mainz Fritz‐Strassmann‐Weg 2 55128 Mainz Germany
| |
Collapse
|
4
|
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: 832] [Impact Index Per Article: 166.4] [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.
Collapse
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
| |
Collapse
|
5
|
Gündüz S, Vibhute S, Botár R, Kálmán FK, Tóth I, Tircsó G, Regueiro-Figueroa M, Esteban-Gómez D, Platas-Iglesias C, Angelovski G. Coordination Properties of GdDO3A-Based Model Compounds of Bioresponsive MRI Contrast Agents. Inorg Chem 2018; 57:5973-5986. [PMID: 29718660 DOI: 10.1021/acs.inorgchem.8b00473] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We report a detailed characterization of the thermodynamic stability and dissociation kinetics of Gd3+ complexes with DO3A derivatives containing a (methylethylcarbamoylmethylamino)acetic acid (L1), (methylpropylcarbamoylmethylamino)acetic acid (L2), 2-dimethylamino- N-ethylacetamide (L3), or 2-dimethylamino- N-propylacetamide (L4) group attached to the fourth nitrogen atom of the macrocyclic unit. These ligands are model systems of Ca2+- and Zn2+-responsive contrast agents (CA) for application in magnetic resonance imaging (MRI). The results of the potentiometric studies ( I = 0.15 M NaCl) provide stability constants with log KGdL values in the range 13.9-14.8. The complex speciation in solution was found to be quite complicated due to the formation of protonated species at low pH, hydroxido complexes at high pH, and stable dinuclear complexes in the case of L1,2. At neutral pH significant fractions of the complexes are protonated at the amine group of the amide side chain (log KGdL×H = 7.2-8.1). These ligands form rather weak complexes with Mg2+ and Ca2+ but very stable complexes with Cu2+ (log KCuL = 20.4-22.3) and Zn2+ (log KZnL = 15.5-17.6). Structural studies using a combination of 1H NMR and luminescence spectroscopy show that the amide group of the ligand is coordinated to the metal ion at pH ∼8.5, while protonation of the amine group provokes the decoordination of the amide O atom and a concomitant increase in the hydration number and proton relaxivity. The dissociation of the complexes occurs mainly through a rather efficient proton-assisted pathway, which results in kinetic inertness comparable to that of nonmacrocyclic ligands such as DTPA rather than DOTA-like complexes.
Collapse
Affiliation(s)
- Serhat Gündüz
- MR Neuroimaging Agents , Max Planck Institute for Biological Cybernetics , D-72076 Tuebingen , Germany
| | - Sandip Vibhute
- MR Neuroimaging Agents , Max Planck Institute for Biological Cybernetics , D-72076 Tuebingen , Germany
| | - Richard Botár
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Ferenc K Kálmán
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Imre Tóth
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Gyula Tircsó
- Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Martín Regueiro-Figueroa
- Centro de Investigaciones Científicas Avanzadas (CICA) and Departamento de Química , Universidade da Coruña , Campus da Zapateira, Rúa da Fraga 10 , 15008 A Coruña , Spain
| | - David Esteban-Gómez
- Centro de Investigaciones Científicas Avanzadas (CICA) and Departamento de Química , Universidade da Coruña , Campus da Zapateira, Rúa da Fraga 10 , 15008 A Coruña , Spain
| | - Carlos Platas-Iglesias
- Centro de Investigaciones Científicas Avanzadas (CICA) and Departamento de Química , Universidade da Coruña , Campus da Zapateira, Rúa da Fraga 10 , 15008 A Coruña , Spain
| | - Goran Angelovski
- MR Neuroimaging Agents , Max Planck Institute for Biological Cybernetics , D-72076 Tuebingen , Germany
| |
Collapse
|
6
|
Granato L, Vander Elst L, Henoumont C, Muller RN, Laurent S. Optimizing Water Exchange Rates and Rotational Mobility for High-Relaxivity of a Novel Gd-DO3A Derivative Complex Conjugated to Inulin as Macromolecular Contrast Agents for MRI. Chem Biodivers 2018; 15. [PMID: 29460387 DOI: 10.1002/cbdv.201700487] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 12/13/2017] [Indexed: 11/07/2022]
Abstract
Thanks to the understanding of the relationships between the residence lifetime τM of the coordinated water molecules to macrocyclic Gd-complexes and the rotational mobility τR of these structures, and according to the theory for paramagnetic relaxation, it is now possible to design macromolecular contrast agents with enhanced relaxivities by optimizing these two parameters through ligand structural modification. We succeeded in accelerating the water exchange rate by inducing steric compression around the water binding site, and by removing the amide function from the DOTA-AA ligand [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono(p-aminoanilide)] (L) previously designed. This new ligand 10[2(1-oxo-1-p-propylthioureidophenylpropyl]-1,4,7,10-tetraazacyclodecane-1,4,7-tetraacetic acid (L1 ) was then covalently conjugated to API [O-(aminopropyl)inulin] to get the complex API-(GdL1 )x with intent to slow down the rotational correlation time (τR ) of the macromolecular complex. The evaluation of the longitudinal relaxivity at different magnetic fields and the study of the 17 O-NMR at variable temperature of the low-molecular-weight compound (GdL1 ) showed a slight decrease of the τM value (τM310 = 331 ns vs. τM310 = 450 ns for the GdL complex). Consequently to the increase of the size of the API-(GdL1 )x complex, the rotational correlation time becomes about 360 times longer compared to the monomeric GdL1 complex (τR = 33,700 ps), which results in an enhanced proton relaxivity.
Collapse
Affiliation(s)
- Luigi Granato
- General, Organic and Biomedical Chemistry Unit, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau, 19, B-7000, Mons, Belgium
| | - Luce Vander Elst
- General, Organic and Biomedical Chemistry Unit, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau, 19, B-7000, Mons, Belgium
| | - Celine Henoumont
- General, Organic and Biomedical Chemistry Unit, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau, 19, B-7000, Mons, Belgium
| | - Robert N Muller
- General, Organic and Biomedical Chemistry Unit, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau, 19, B-7000, Mons, Belgium.,Center for Microscopy and Molecular Imaging (CMMI), Rue A. Bolland, 8, B-6041, Gosselies, Belgium
| | - Sophie Laurent
- General, Organic and Biomedical Chemistry Unit, NMR and Molecular Imaging Laboratory, University of Mons, Avenue Maistriau, 19, B-7000, Mons, Belgium.,Center for Microscopy and Molecular Imaging (CMMI), Rue A. Bolland, 8, B-6041, Gosselies, Belgium
| |
Collapse
|
7
|
A Coordination Chemistry Approach to Fine-Tune the Physicochemical Parameters of Lanthanide Complexes Relevant to Medical Applications. Chemistry 2018; 24:3127-3131. [DOI: 10.1002/chem.201705528] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Indexed: 12/23/2022]
|
8
|
Tei L, Baranyai Z, Gaino L, Forgács A, Vágner A, Botta M. Thermodynamic stability, kinetic inertness and relaxometric properties of monoamide derivatives of lanthanide(III) DOTA complexes. Dalton Trans 2015; 44:5467-78. [PMID: 25695351 DOI: 10.1039/c4dt03939d] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A complete thermodynamic and kinetic solution study on lanthanide(III) complexes with monoacetamide (DOTAMA, L1) and monopropionamide (DOTAMAP, L2) derivatives of DOTA (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) was undertaken with the aim to elucidate their stability and inertness in aqueous media. The stability constants of GdL1 and GdL2 are comparable, whereas a more marked difference is found in the kinetic inertness of the two complexes. The formation of the Eu(III) and Ce(III) complexes takes place via the formation of the protonated intermediates which can deprotonate and transform into the final complex through a OH(-) assisted pathway. GdL2 shows faster rates of acid catalysed decomplexation with respect to GdL1, which has a kinetic inertness comparable to GdDOTA. Nevertheless, GdL2 is one order of magnitude more inert than GdDO3A. A novel DOTAMAP-based bifunctional chelating ligand and its deoxycholic acid derivative (L5) were also synthesized. Since the coordinated water molecule in GdL2 is characterized by an exchange rate ca. two orders of magnitude greater than in GdL1, the relaxivity of the macromolecular derivatives of L5 should not be limited by the slow water exchange process. The relaxometric properties of the supramolecular adduct of GdL5 with human serum albumin (HSA) were investigated in aqueous solution by measuring the magnetic field dependence of the (1)H relaxivity which, at 20 MHz and 298 K, shows a 430% increase over that of the unbound GdL5 chelate. Thus, Gd(III) complexes with DOTAMAP macrocyclic ligands can represent good candidates for the development of stable and highly effective bioconjugate systems for molecular imaging applications.
Collapse
Affiliation(s)
- Lorenzo Tei
- Dipartimento di Scienze ed Innovazione Tecnologica, Università del Piemonte Orientale "Amedeo Avogadro", Viale T. Michel 11, I-15121, Alessandria, Italy.
| | | | | | | | | | | |
Collapse
|
9
|
De León-Rodríguez LM, Martins AF, Pinho MC, Rofsky NM, Sherry AD. Basic MR relaxation mechanisms and contrast agent design. J Magn Reson Imaging 2015; 42:545-65. [PMID: 25975847 DOI: 10.1002/jmri.24787] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 10/11/2014] [Indexed: 12/22/2022] Open
Abstract
The diagnostic capabilities of magnetic resonance imaging (MRI) have undergone continuous and substantial evolution by virtue of hardware and software innovations and the development and implementation of exogenous contrast media. Thirty years since the first MRI contrast agent was approved for clinical use, a reliance on MR contrast media persists, largely to improve image quality with higher contrast resolution and to provide additional functional characterization of normal and abnormal tissues. Further development of MR contrast media is an important component in the quest for continued augmentation of diagnostic capabilities. In this review we detail the many important considerations when pursuing the design and use of MR contrast media. We offer a perspective on the importance of chemical stability, particularly kinetic stability, and how this influences one's thinking about the safety of metal-ligand-based contrast agents. We discuss the mechanisms involved in MR relaxation in the context of probe design strategies. A brief description of currently available contrast agents is accompanied by an in-depth discussion that highlights promising MRI contrast agents in the development of future clinical and research applications. Our intention is to give a diverse audience an improved understanding of the factors involved in developing new types of safe and highly efficient MR contrast agents and, at the same time, provide an appreciation of the insights into physiology and disease that newer types of responsive agents can provide.
Collapse
Affiliation(s)
| | - André F Martins
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas, USA
| | - Marco C Pinho
- Department of Radiology and the Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Neil M Rofsky
- Department of Radiology and the Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - A Dean Sherry
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas, USA.,Department of Radiology and the Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
10
|
Chilla SNM, Laurent S, Vander Elst L, Muller RN. Synthesis and characterization of a new lanthanide based MRI contrast agent, potential and versatile tracer for multimodal imaging. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.06.126] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
11
|
Designing reactivity-based responsive lanthanide probes for multicolor detection in biological systems. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.10.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
12
|
Molnár E, Camus N, Patinec V, Rolla GA, Botta M, Tircsó G, Kálmán FK, Fodor T, Tripier R, Platas-Iglesias C. Picolinate-containing macrocyclic Mn2+ complexes as potential MRI contrast agents. Inorg Chem 2014; 53:5136-49. [PMID: 24773460 DOI: 10.1021/ic500231z] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report the synthesis of the ligand Hnompa (6-((1,4,7-triazacyclononan-1-yl)methyl)picolinic acid) and a detailed characterization of the Mn(2+) complexes formed by this ligand and the related ligands Hdompa (6-((1,4,7,10-tetraazacyclododecan-1-yl)methyl)picolinic acid) and Htempa (6-((1,4,8,11-tetraazacyclotetradecan-1-yl)methyl)picolinic acid). These ligands form thermodynamically stable complexes in aqueous solution with stability constants of logKMnL = 10.28(1) (nompa), 14.48(1) (dompa), and 12.53(1) (tempa). A detailed study of the dissociation kinetics of these Mn(2+) complexes indicates that the decomplexation reaction at about neutral pH occurs mainly following a spontaneous dissociation mechanism. The X-ray structure of [Mn2(nompa)2(H2O)2](ClO4)2 shows that the Mn(2+) ion is seven-coordinate in the solid state, being directly bound to five donor atoms of the ligand, the oxygen atom of a coordinated water molecule and an oxygen atom of a neighboring nompa(-) ligand acting as a bridging bidentate carboxylate group (μ-η(1)-carboxylate). Nuclear magnetic relaxation dispersion ((1)H NMRD) profiles and (17)O NMR chemical shifts and transverse relaxation rates of aqueous solutions of [Mn(nompa)](+) indicate that the Mn(2+) ion is six-coordinate in solution by the pentadentate ligand and one inner-sphere water molecule. The analysis of the (1)H NMRD and (17)O NMR data provides a very high water exchange rate of the inner-sphere water molecule (kex(298) = 2.8 × 10(9) s(-1)) and an unusually high value of the (17)O hyperfine coupling constant of the coordinated water molecule (AO/ℏ = 73.3 ± 0.6 rad s(-1)). DFT calculations performed on the [Mn(nompa)(H2O)](+)·2H2O system (TPSSh model) provide a AO/ℏ value in excellent agreement with the one obtained experimentally.
Collapse
Affiliation(s)
- Enikő Molnár
- Departamento de Química Fundamental, Facultade de Ciencias, Universidade da Coruña , Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Ferreira MF, Pereira G, Martins AF, Martins CIO, Prata MIM, Petoud S, Toth E, Ferreira PMT, Martins JA, Geraldes CFGC. Ln[DO3A-N-α-(pyrenebutanamido)propionate] complexes: optimized relaxivity and NIR optical properties. Dalton Trans 2014; 43:3162-73. [DOI: 10.1039/c3dt52958d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
14
|
Polasek M, Caravan P. Is macrocycle a synonym for kinetic inertness in Gd(III) Complexes? Effect of coordinating and noncoordinating substituents on inertness and relaxivity of Gd(III) chelates with DO3A-like ligands. Inorg Chem 2013; 52:4084-96. [PMID: 23517079 PMCID: PMC3640422 DOI: 10.1021/ic400227k] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gadolinium chelates with octadentate ligands are widely used as contrast agents for magnetic resonance imaging (MRI), with macrocyclic ligands based on DO3A being preferred for the high kinetic inertness of their Gd chelates. A major challenge in the design of new bifunctional MRI probes is the need to control the rotational motion of the chelate, which greatly affects its relaxivity. In this work we explored facile alkylation of a secondary amine in macrocyclic DO3A-like ligands to create a short, achiral linkage to limit the undesired internal motion of chelates within larger molecular constructs. The acetate moiety on the trans nitrogen was also replaced with either a bidentate (ethoxyacetate, L1 or methyl picolinate, L2) or bulky monodentate (methyl phosphonate, L3) donor arm to give octa- or heptadentate ligands, respectively. The resultant Gd(III) complexes were all monohydrated (q = 1) and exhibited water residency times that spanned 2 orders of magnitude (τM = 2190 ± 170, 3500 ± 90, and 12.7 ± 3.8 ns at 37 °C for GdL1, GdL2, and GdL3, respectively). Alkylation of the secondary amine with a noncoordinating biphenyl moiety resulted in coordinatively saturated q = 0 complexes of octadentate ligands L1 and L2. Relaxivities were limited by slow water exchange and/or lack of water coligand. All complexes showed decreased inertness compared to [Gd(DO3A)] despite higher ligand denticity, and inertness was further decreased upon N-alkylation. These results demonstrate that high kinetic inertness and in vivo safety of Gd chelates with macrocyclic ligands should not be generalized.
Collapse
Affiliation(s)
- Miloslav Polasek
- The Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, MA 02129
| | - 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, MA 02129
| |
Collapse
|
15
|
Lima LMP, Delgado R, Hermann P, Ševčík R, Lubal P, Carvalho HF, Martins AF, Tóth É, Geraldes CFGC. Tris(phosphonomethyl)cyclen Derivatives: Thermodynamic Stability, Kinetics, Solution Structure, and Relaxivity of Ln3+ Complexes. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201101335] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
16
|
Strauch RC, Mastarone DJ, Sukerkar PA, Song Y, Ipsaro JJ, Meade TJ. Reporter protein-targeted probes for magnetic resonance imaging. J Am Chem Soc 2011; 133:16346-9. [PMID: 21942425 DOI: 10.1021/ja206134b] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Contrast agents for magnetic resonance imaging are frequently employed as experimental and clinical probes. Drawbacks include low signal sensitivity, fast clearance, and nonspecificity that limit efficacy in experimental imaging. In order to create a bioresponsive MR contrast agent, a series of four Gd(III) complexes targeted to the HaloTag reporter were designed and synthesized. HaloTag is unique among reporter proteins for its specificity, versatility, and the covalent interaction between substrate and protein. In similar systems, these properties produce prolonged in vivo lifetimes and extended imaging opportunities for contrast agents, longer rotational correlation times, and increases in relaxivity (r(1)) upon binding to the HaloTag protein. In this work we report a new MR contrast probe, 2CHTGd, which forms a covalent bond with its target protein and results in a dramatic increase in sensitivity. A 6-fold increase in r(1), from 3.8 to 22 mM(-1) s(-1), is observed upon 2CHTGd binding to the target protein. This probe was designed for use with the HaloTag protein system which allows for a variety of substrates (specific for MRI, florescence, or protein purification applications) to be used with the same reporter.
Collapse
Affiliation(s)
- Renee C Strauch
- Department of Molecular Biosciences, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA
| | | | | | | | | | | |
Collapse
|
17
|
Regueiro-Figueroa M, Bensenane B, Ruscsák E, Esteban-Gómez D, Charbonnière LJ, Tircsó G, Tóth I, de Blas A, Rodríguez-Blas T, Platas-Iglesias C. Lanthanide dota-like complexes containing a picolinate pendant: structural entry for the design of Ln(III)-based luminescent probes. Inorg Chem 2011; 50:4125-41. [PMID: 21456610 DOI: 10.1021/ic2001915] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this contribution we present two ligands based on a do3a platform containing a picolinate group attached to the fourth nitrogen atom of the cyclen unit, which are designed for stable lanthanide complexation in aqueous solutions. Potentiometric measurements reveal that the thermodynamic stability of the complexes is very high (log K = 21.2-23.5), being comparable to that of the dota analogues. Luminescence lifetime measurements performed on solutions of the Eu(III) and Tb(III) complexes indicate that the complexes are nine coordinate with no inner-sphere water molecules. A combination of density functional theory (DFT) calculations and NMR measurements shows that for the complexes of the heaviest lanthanides there is a major isomer in solution consisting of the enantiomeric pair Λ(δδδδ) and Δ(λλλλ), which provides square antiprismatic coordination (SAP) around the metal ion. Analysis of the Yb(III)-induced paramagnetic shifts unambiguously confirms that these complexes have SAP coordination in aqueous solution. For the light lanthanide ions however both the SAP and twisted-square antiprismatic (TSAP) isomers are present in solution. Inversion of the cyclen ring appears to be the rate-determining step for the Λ(δδδδ) ↔ Δ(λλλλ) enantiomerization process observed in the Lu(III) complexes. The energy barriers obtained from NMR measurements for this dynamic process are in excellent agreement with those predicted by DFT calculations. The energy barriers calculated for the arm-rotation process are considerably lower than those obtained for the ring-inversion path. Kinetic studies show that replacement of an acetate arm of dota by a picolinate pendant results in a 3-fold increase in the formation rate of the corresponding Eu(III) complexes and a significant increase of the rates of acid-catalyzed dissociation of the complexes. However, these rates are 1-2 orders of magnitude lower than those of do3a analogues, which shows that the complexes reported herein are remarkably inert with respect to metal ion dissociation.
Collapse
Affiliation(s)
- Martín Regueiro-Figueroa
- Departamento de Química Fundamental, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15008 A Coruña, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Tan M, Wu X, Jeong EK, Chen Q, Parker DL, Lu ZR. An effective targeted nanoglobular manganese(II) chelate conjugate for magnetic resonance molecular imaging of tumor extracellular matrix. Mol Pharm 2010; 7:936-43. [PMID: 20481565 DOI: 10.1021/mp100054m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Stable manganese(II) chelates are of great interest for the design and development of safe and effective non-gadolinium(III)-based targeted MRI contrast agents for MR cancer molecular imaging. In this study, a CLT1 peptide targeted G3 nanoglobular Mn(II)-DOTA monoamide conjugate was designed and synthesized as a targeted MRI contrast agent for molecular imaging of the fibrin-fibronectin complexes or oncofetal fibronectin in tumor stroma. The targeted contrast agent comprised 2 peptides and 42 Mn(II)-DOTA chelates on the surface of the G3 nanoglobule. The T(1) and T(2) relaxivities of the targeted agent at room temperature were 3.13 and 8.74 mM(-1) s(-1) per Mn(II) chelate at 3 T (tesla), respectively. It had a well-defined nanosize (5.2 nm) and could be readily excreted via renal filtration. The targeted nanoglobular contrast agent specifically bound to tumor tissue, resulting in significant tumor contrast enhancement with minimal nonspecific enhancement in the liver of tumor bearing mice as compared to a nontargeted control at a dose as low as 0.03 mmol-Mn/kg. The targeted G3 nanoglobular Mn(II)-DOTA conjugate is promising as a targeted non-gadolinium(III)-based MRI contrast agent for MR cancer molecular imaging.
Collapse
Affiliation(s)
- Mingqian Tan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | | | | | | | | | | |
Collapse
|
19
|
Tircsó G, Benyó ET, Suh EH, Jurek P, Kiefer GE, Sherry AD, Kovács Z. (S)-5-(p-nitrobenzyl)-PCTA, a promising bifunctional ligand with advantageous metal ion complexation kinetics. Bioconjug Chem 2010; 20:565-75. [PMID: 19220012 DOI: 10.1021/bc8004914] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A bifunctional version of PCTA (3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6,9,-triacetic acid) that exhibits fast complexation kinetics with the trivalent lanthanide(III) ions was synthesized in reasonable yields starting from N,N',N''-tristosyl-(S)-2-(p-nitrobenzyl)-diethylenetriamine. pH-potentiometric studies showed that the basicities of p-nitrobenzyl-PCTA and the parent ligand PCTA were similar. The stability of M(NO(2)-Bn-PCTA) (M = Mg(2+), Ca(2+), Cu(2+), Zn(2+)) complexes was similar to that of the corresponding PCTA complexes, while the stability of Ln(3+) complexes of the bifunctional ligand is somewhat lower than that of PCTA chelates. The rate of complex formation of Ln(NO(2)-Bn-PCTA) complexes was found to be quite similar to that of PCTA, a ligand known to exhibit the fastest formation rates among all lanthanide macrocyclic ligand complexes studied to date. The acid-catalyzed decomplexation kinetic studies of the selected Ln(NO(2)-Bn-PCTA) complexes showed that the kinetic inertness of the complexes was comparable to that of Ln(DOTA) chelates making the bifunctional ligand NO(2)-Bn-PCTA suitable for labeling biological vectors with radioisotopes for nuclear medicine applications.
Collapse
Affiliation(s)
- Gyula Tircsó
- Department of Chemistry, University of Texas at Dallas, Richardson, TX 75080, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
|
21
|
Armelao L, Quici S, Barigelletti F, Accorsi G, Bottaro G, Cavazzini M, Tondello E. Design of luminescent lanthanide complexes: From molecules to highly efficient photo-emitting materials. Coord Chem Rev 2010. [DOI: 10.1016/j.ccr.2009.07.025] [Citation(s) in RCA: 765] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
22
|
Nonat A, Giraud M, Gateau C, Fries PH, Helm L, Mazzanti M. Gadolinium(III) complexes of 1,4,7-triazacyclononane based picolinate ligands: simultaneous optimization of water exchange kinetics and electronic relaxation. Dalton Trans 2009:8033-46. [DOI: 10.1039/b907738c] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
23
|
Tei L, Gugliotta G, Baranyai Z, Botta M. A new bifunctional GdIII complex of enhanced efficacy for MR-molecular imaging applications. Dalton Trans 2009:9712-4. [DOI: 10.1039/b917566k] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
24
|
Design and function of metal complexes as contrast agents in MRI. ADVANCES IN INORGANIC CHEMISTRY 2009. [DOI: 10.1016/s0898-8838(09)00202-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
25
|
Ferreira MF, Martins AF, Martins JA, Ferreira PM, Tóth É, Geraldes CF. Gd(DO3A-N-α-aminopropionate): a versatile and easily available synthon with optimized water exchange for the synthesis of high relaxivity, targeted MRI contrast agents. Chem Commun (Camb) 2009:6475-7. [DOI: 10.1039/b912201j] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
26
|
Hermann P, Kotek J, Kubícek V, Lukes I. Gadolinium(III) complexes as MRI contrast agents: ligand design and properties of the complexes. Dalton Trans 2008:3027-47. [PMID: 18521444 DOI: 10.1039/b719704g] [Citation(s) in RCA: 381] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetic resonance imaging is a commonly used diagnostic method in medicinal practice as well as in biological and preclinical research. Contrast agents (CAs), which are often applied are mostly based on Gd(III) complexes. In this paper, the ligand types and structures of their complexes on one side and a set of the physico-chemical parameters governing properties of the CAs on the other side are discussed. The solid-state structures of lanthanide(III) complexes of open-chain and macrocyclic ligands and their structural features are compared. Examples of tuning of ligand structures to alter the relaxometric properties of gadolinium(III) complexes as a number of coordinated water molecules, their residence time (exchange rate) or reorientation time of the complexes are given. Influence of the structural changes of the ligands on thermodynamic stability and kinetic inertness/lability of their lanthanide(III) complexes is discussed.
Collapse
Affiliation(s)
- Petr Hermann
- Department of Inorganic Chemistry, Faculty of Science, Universita Karlova (Charles University), Hlavova 2030, 128 40, Prague 2, Czech Republic
| | | | | | | |
Collapse
|
27
|
|