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Igarashi T, Kim H, Sun PZ. Detection of tissue pH with quantitative chemical exchange saturation transfer magnetic resonance imaging. NMR IN BIOMEDICINE 2023; 36:e4711. [PMID: 35141979 PMCID: PMC10249910 DOI: 10.1002/nbm.4711] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/03/2022] [Accepted: 02/05/2022] [Indexed: 05/12/2023]
Abstract
Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) has emerged as a novel means for sensitive detection of dilute labile protons and chemical exchange rates. By sensitizing to pH-dependent chemical exchange, CEST MRI has shown promising results in monitoring tissue statuses such as pH changes in disorders like acute stroke, tumor, and acute kidney injury. This article briefly reviews the basic principles for CEST imaging and quantitative measures, from the simplistic asymmetry analysis to multipool Lorentzian decoupling and quasi-steady-state reconstruction. In particular, the advantages and limitations of commonly used quantitative approaches for CEST applications are discussed.
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Affiliation(s)
- Takahiro Igarashi
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA
| | - Hahnsung Kim
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA
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2
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Zakaria ABM, Huang Y, Coman D, Mishra SK, Mihailovic JM, Maritim S, Rojas-Quijano FA, Jurek P, Kiefer GE, Hyder F. Methylated tetra-amide derivatives of paramagnetic complexes for magnetic resonance biosensing with both BIRDS and CEST. NMR IN BIOMEDICINE 2022; 35:e4687. [PMID: 34970801 DOI: 10.1002/nbm.4687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 12/22/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
Paramagnetic agents that utilize two mechanisms to provide physiological information by magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) are described. MRI with chemical exchange saturation transfer (CEST) takes advantage of the agent's exchangeable protons (e.g., -OH or -NHx , where 2 ≥ x ≥ 1) to create pH contrast. The agent's incorporation of non-exchangeable protons (e.g., -CHy , where 3 ≥ y ≥ 1) makes it possible to map tissue temperature and/or pH using an MRSI method called biosensor imaging of redundant deviation in shifts (BIRDS). Hybrid probes based upon 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate chelate (DOTA4- ) and its methylated analog (1,4,7,10-tetraazacyclododecane-α, α', α″, α‴-tetramethyl-1,4,7,10-tetraacetate, DOTMA4- ) were synthesized, and modified to create new tetra-amide chelates. Addition of several methyl groups per pendent arm of the symmetrical chelates, positioned proximally and distally to thulium ions (Tm3+ ), gave rise to favorable BIRDS properties (i.e., high signal-to-noise ratio (SNR) from non-exchangeable methyl proton peaks) and CEST responsiveness (i.e., from amide exchangeable protons). Structures of the Tm3+ probes elucidate the influence of methyl group placement on sensor performance. An eight-coordinate geometry with high symmetry was observed for the complexes: Tm-L1 was based on DOTA4- , whereas Tm-L2 and Tm-L3 were based on DOTMA4- , where the latter contained an additional carboxylate at the distal end of each arm. The distance of Tm3+ from terminal methyl carbons is a key determinant for sustaining BIRDS temperature sensitivity without compromising CEST pH contrast; however, water solubility was influenced by introduction of hydrophobic methyl groups and hydrophilic carboxylate. Combined BIRDS and CEST detection of Tm-L2, which features two high-SNR methyl peaks and a strong amide CEST peak, should enable simultaneous temperature and pH measurements for high-resolution molecular imaging in vivo.
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Affiliation(s)
- Abul B M Zakaria
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Yuegao Huang
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Daniel Coman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Sandeep K Mishra
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Jelena M Mihailovic
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Samuel Maritim
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | | | | | | | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
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3
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Mihailovic JM, Huang Y, Walsh JJ, Khan MH, Mishra SK, Samuels S, Hyder F, Coman D. High-resolution pH imaging using ratiometric chemical exchange saturation transfer combined with biosensor imaging of redundant deviation in shifts featuring paramagnetic DOTA-tetraglycinate agents. NMR IN BIOMEDICINE 2022; 35:e4658. [PMID: 34837412 DOI: 10.1002/nbm.4658] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 11/06/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Chemical exchange saturation transfer (CEST) and biosensor imaging of redundant deviation in shifts (BIRDS) methods differ respectively by detecting exchangeable and nonexchangeable proton signals by magnetic resonance. Because CEST contrast depends on both temperature and pH, simultaneous CEST and BIRDS imaging can be employed to separate these contributions. Here, we test if high-resolution pH imaging in vivo is possible with ratiometric CEST calibrated for temperature variations measured by BIRDS. Thulium- and europium-based DOTA-tetraglycinate agents, TmDOTA-(gly)4- and EuDOTA-(gly)4- , were used for high-resolution pH mapping in vitro and in vivo, using BIRDS for temperature adjustments needed for a more accurate ratiometric CEST approach. Although neither agent showed pH dependence with BIRDS in vitro in the pH range 6 to 8, each one's temperature sensitivity was enhanced when mixed because of increased redundancy. By contrast, the CEST signal of each agent was affected by the presence of the other agent in vitro. However, pH could be measured more accurately when temperature from BIRDS was detected. These in vitro calibrations with TmDOTA-(gly)4- and EuDOTA-(gly)4- enabled high-resolution pH imaging of glioblastoma in rat brains. It was concluded that temperature mapping with BIRDS can calibrate the ratiometric CEST signal from a cocktail of TmDOTA-(gly)4- and EuDOTA-(gly)4- agents to provide temperature-independent absolute pH imaging in vivo.
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Affiliation(s)
- Jelena M Mihailovic
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Yuegao Huang
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - John J Walsh
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Muhammad H Khan
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Sandeep K Mishra
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Sara Samuels
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
| | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Daniel Coman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut, USA
- Magnetic Resonance Research Center, Yale University, New Haven, Connecticut, USA
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4
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Khan MH, Mishra SK, Zakaria ABM, Mihailović JM, Coman D, Hyder F. Comparison of Lanthanide Macrocyclic Complexes as 23Na NMR Sensors. Anal Chem 2022; 94:2536-2545. [DOI: 10.1021/acs.analchem.1c04432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Muhammad H. Khan
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Sandeep Kumar Mishra
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, Connecticut 06520, United States
| | - A. B. M. Zakaria
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, Connecticut 06520, United States
| | - Jelena M. Mihailović
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, Connecticut 06520, United States
| | - Daniel Coman
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, Connecticut 06520, United States
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut 06520, United States
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, Connecticut 06520, United States
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5
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Walsh JJ, Parent M, Akif A, Adam LC, Maritim S, Mishra SK, Khan MH, Coman D, Hyder F. Imaging Hallmarks of the Tumor Microenvironment in Glioblastoma Progression. Front Oncol 2021; 11:692650. [PMID: 34513675 PMCID: PMC8426346 DOI: 10.3389/fonc.2021.692650] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/05/2021] [Indexed: 11/18/2022] Open
Abstract
Glioblastoma progression involves multifaceted changes in vascularity, cellularity, and metabolism. Capturing such complexities of the tumor niche, from the tumor core to the periphery, by magnetic resonance imaging (MRI) and spectroscopic imaging (MRSI) methods has translational impact. In human-derived glioblastoma models (U87, U251) we made simultaneous and longitudinal measurements of tumor perfusion (Fp), permeability (Ktrans), and volume fractions of extracellular (ve) and blood (vp) spaces from dynamic contrast enhanced (DCE) MRI, cellularity from apparent diffusion coefficient (ADC) MRI, and extracellular pH (pHe) from an MRSI method called Biosensor Imaging of Redundant Deviation in Shifts (BIRDS). Spatiotemporal patterns of these parameters during tumorigenesis were unique for each tumor. While U87 tumors grew faster, Fp, Ktrans, and vp increased with tumor growth in both tumors but these trends were more pronounced for U251 tumors. Perfused regions between tumor periphery and core with U87 tumors exhibited higher Fp, but Ktrans of U251 tumors remained lowest at the tumor margin, suggesting primitive vascularization. Tumor growth was uncorrelated with ve, ADC, and pHe. U87 tumors showed correlated regions of reduced ve and lower ADC (higher cellularity), suggesting ongoing proliferation. U251 tumors revealed that the tumor core had higher ve and elevated ADC (lower cellularity), suggesting necrosis development. The entire tumor was uniformly acidic (pHe 6.1-6.8) early and throughout progression, but U251 tumors were more acidic, suggesting lower aerobic glycolysis in U87 tumors. Characterizing these cancer hallmarks with DCE-MRI, ADC-MRI, and BIRDS-MRSI will be useful for exploring tumorigenesis as well as timely therapies targeted to specific vascular and metabolic aspects of the tumor microenvironment.
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Affiliation(s)
- John J Walsh
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States
| | - Maxime Parent
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States.,Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
| | - Adil Akif
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States
| | - Lucas C Adam
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States.,Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
| | - Samuel Maritim
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States
| | - Sandeep K Mishra
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States.,Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
| | - Muhammad H Khan
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States
| | - Daniel Coman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States.,Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT, United States.,Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States.,Magnetic Resonance Research Center, Yale University, New Haven, CT, United States
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6
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Moody AS, Dayton PA, Zamboni WC. Imaging methods to evaluate tumor microenvironment factors affecting nanoparticle drug delivery and antitumor response. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2021; 4:382-413. [PMID: 34796317 PMCID: PMC8597952 DOI: 10.20517/cdr.2020.94] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/07/2021] [Accepted: 01/28/2021] [Indexed: 11/24/2022]
Abstract
Standard small molecule and nanoparticulate chemotherapies are used for cancer treatment; however, their effectiveness remains highly variable. One reason for this variable response is hypothesized to be due to nonspecific drug distribution and heterogeneity of the tumor microenvironment, which affect tumor delivery of the agents. Nanoparticle drugs have many theoretical advantages, but due to variability in tumor microenvironment (TME) factors, the overall drug delivery to tumors and associated antitumor response are low. The nanotechnology field would greatly benefit from a thorough analysis of the TME factors that create these physiological barriers to tumor delivery and treatment in preclinical models and in patients. Thus, there is a need to develop methods that can be used to reveal the content of the TME, determine how these TME factors affect drug delivery, and modulate TME factors to increase the tumor delivery and efficacy of nanoparticles. In this review, we will discuss TME factors involved in drug delivery, and how biomedical imaging tools can be used to evaluate tumor barriers and predict drug delivery to tumors and antitumor response.
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Affiliation(s)
- Amber S. Moody
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Carolina Institute for Nanomedicine, Chapel Hill, NC 27599, USA
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA
| | - Paul A. Dayton
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA
| | - William C. Zamboni
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599, USA
- UNC Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
- Carolina Institute for Nanomedicine, Chapel Hill, NC 27599, USA
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7
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Khan MH, Walsh JJ, Mihailović JM, Mishra SK, Coman D, Hyder F. Imaging the transmembrane and transendothelial sodium gradients in gliomas. Sci Rep 2021; 11:6710. [PMID: 33758290 PMCID: PMC7987982 DOI: 10.1038/s41598-021-85925-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 03/08/2021] [Indexed: 11/29/2022] Open
Abstract
Under normal conditions, high sodium (Na+) in extracellular (Na+e) and blood (Na+b) compartments and low Na+ in intracellular milieu (Na+i) produce strong transmembrane (ΔNa+mem) and weak transendothelial (ΔNa+end) gradients respectively, and these manifest the cell membrane potential (Vm) as well as blood–brain barrier (BBB) integrity. We developed a sodium (23Na) magnetic resonance spectroscopic imaging (MRSI) method using an intravenously-administered paramagnetic polyanionic agent to measure ΔNa+mem and ΔNa+end. In vitro 23Na-MRSI established that the 23Na signal is intensely shifted by the agent compared to other biological factors (e.g., pH and temperature). In vivo 23Na-MRSI showed Na+i remained unshifted and Na+b was more shifted than Na+e, and these together revealed weakened ΔNa+mem and enhanced ΔNa+end in rat gliomas (vs. normal tissue). Compared to normal tissue, RG2 and U87 tumors maintained weakened ΔNa+mem (i.e., depolarized Vm) implying an aggressive state for proliferation, whereas RG2 tumors displayed elevated ∆Na+end suggesting altered BBB integrity. We anticipate that 23Na-MRSI will allow biomedical explorations of perturbed Na+ homeostasis in vivo.
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Affiliation(s)
- Muhammad H Khan
- Department of Biomedical Engineering, Yale University, N143 TAC (MRRC), 300 Cedar Street, New Haven, CT, 06520, USA.
| | - John J Walsh
- Department of Biomedical Engineering, Yale University, N143 TAC (MRRC), 300 Cedar Street, New Haven, CT, 06520, USA
| | - Jelena M Mihailović
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA
| | - Sandeep K Mishra
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA
| | - Daniel Coman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, N143 TAC (MRRC), 300 Cedar Street, New Haven, CT, 06520, USA. .,Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, 06520, USA.
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8
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De A, Bala S, Saha S, Das KS, Akhtar S, Adhikary A, Ghosh A, Huang GZ, Chowdhuri SP, Das BB, Tong ML, Mondal R. Lanthanide clusters of phenanthroline containing a pyridine-pyrazole based ligand: magnetism and cell imaging. Dalton Trans 2021; 50:3593-3609. [PMID: 33624673 DOI: 10.1039/d0dt04122j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this contribution, we report the synthesis, characterization and luminescence-magnetic properties of Ln-clusters (Ln = Gd3+, Eu3+ and Tb3+) using a new pyridine-pyrazole functionalized ligand fitted with a chromophoric phenanthroline backbone. The unorthodox N-rich ligand forms isostructural trinuclear lanthanide complexes with a topology that closely resembles two interdigitating hairpins. The clusters crystallize in chiral space groups and also exhibit chirality for bulk samples, which were further confirmed using solid state CD spectra. Magnetic studies on the complexes reveal their interesting features while the Gd cluster shows a significant cryogenic magnetic cooling behaviour with a moderately high magnetic entropy change of -23.42 J kg-1 K-1 at 7 T and 2 K. On the other hand, Eu and Tb complexes exhibit interesting fluorescence properties. The compounds were subsequently used as fluorescent probes for the imaging of human breast adenocarcinoma (MCF7) cells. Live cell confocal microscopy images show that the complexes penetrate beyond the usual cytoplasm region and can be useful in imaging the nucleus region of MCF7 cells.
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Affiliation(s)
- Avik De
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
| | - Sukhen Bala
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Sayan Saha
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
| | - Krishna Sundar Das
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
| | - Sohel Akhtar
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
| | - Amit Adhikary
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
| | - Arijit Ghosh
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Guo-Zhang Huang
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Srijita Paul Chowdhuri
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Benu Brata Das
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Ming-Liang Tong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Raju Mondal
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
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9
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Hyder F, Coman D. Imaging Extracellular Acidification and Immune Activation in Cancer. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2021; 18. [PMID: 33997581 DOI: 10.1016/j.cobme.2021.100278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Metabolism reveals pathways by which cells, in healthy and disease tissues, use nutrients to fuel their function and (re)growth. However, gene-centric views have dominated cancer hallmarks, relegating metabolic reprogramming that all cells in the tumor niche undergo as an incidental phenomenon. Aerobic glycolysis in cancer is well known, but recent evidence suggests that diverse symbolic traits of cancer cells are derived from oncogene-directed metabolism required for their sustenance and evolution. Cells in the tumor milieu actively metabolize different nutrients, but proficiently secrete acidic by-products using diverse mechanisms to create a hostile ecosystem for host cells, and where local immune cells suffer collateral damage. Since metabolic interactions between cancer and immune cells hold promise for future cancer therapies, here we focus on translational magnetic resonance methods enabling in vivo and simultaneous detection of tumor habitat acidification and immune activation - innovations for monitoring personalized treatments.
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Affiliation(s)
- Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA
- Quantitative Neuroimaging with Magnetic Resonance (QNMR) Research Program, Yale University, New Haven, CT, USA
| | - Daniel Coman
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA
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10
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Caldwell MA, Brue CR, Whittemore TJ, Meade TJ. A Ln(III)-3-hydroxypyridine pH responsive probe optimized by DFT. RSC Adv 2020; 10:8994-8999. [PMID: 32274014 PMCID: PMC7144623 DOI: 10.1039/c9ra11058e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Differences in tissue pH can be diagnostic of cancer and other conditions that shift cell metabolism. Paramagnetic probes are promising tools for pH mapping in vivo using magnetic resonance spectroscopy (MRS) as they provide uniquely shifted MR signals that change with pH. Here, we demonstrate a 3-hydroxy-6-methylpyridyl coordinating group as a new pH-responsive reporter group for Ln(III) MRS probes. The pH response of the complex was observed by UV-Vis, fluorescence, and NMR spectroscopies, and modeled using DFT. These results provide insight into the observed pH-dependent NMR spectrum of the complex. The protonation state of the hydroxypyridine changes the coordinating ability of the ligand, affecting the dipolar field of the lanthanide and the chemical shift of nearby reporter nuclei. The favorable pH response and coordination properties of the 3-hydroxypyridyl group indicates its potential for further development as a dual responsive-reporter group. Incorporation into optimized scaffolds for MRS detection may enable sensitive pH-mapping in vivo.
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Affiliation(s)
- Michael A Caldwell
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, IL, 60208
| | - Christopher R Brue
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, IL, 60208
| | - Tyler J Whittemore
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, IL, 60208
| | - Thomas J Meade
- Departments of Chemistry, Molecular Biosciences, Neurobiology, and Radiology, Northwestern University, Evanston, IL, 60208
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11
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Anemone A, Consolino L, Arena F, Capozza M, Longo DL. Imaging tumor acidosis: a survey of the available techniques for mapping in vivo tumor pH. Cancer Metastasis Rev 2020; 38:25-49. [PMID: 30762162 PMCID: PMC6647493 DOI: 10.1007/s10555-019-09782-9] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cancer cells are characterized by a metabolic shift in cellular energy production, orchestrated by the transcription factor HIF-1α, from mitochondrial oxidative phosphorylation to increased glycolysis, regardless of oxygen availability (Warburg effect). The constitutive upregulation of glycolysis leads to an overproduction of acidic metabolic products, resulting in enhanced acidification of the extracellular pH (pHe ~ 6.5), which is a salient feature of the tumor microenvironment. Despite the importance of pH and tumor acidosis, there is currently no established clinical tool available to image the spatial distribution of tumor pHe. The purpose of this review is to describe various imaging modalities for measuring intracellular and extracellular tumor pH. For each technique, we will discuss main advantages and limitations, pH accuracy and sensitivity of the applied pH-responsive probes and potential translatability to the clinic. Particular attention is devoted to methods that can provide pH measurements at high spatial resolution useful to address the task of tumor heterogeneity and to studies that explored tumor pH imaging for assessing treatment response to anticancer therapies.
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Affiliation(s)
- Annasofia Anemone
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy
| | - Lorena Consolino
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy
| | - Francesca Arena
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Via Nizza 52, Turin, Italy.,Center for Preclinical Imaging, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Ribes 5, Colleretto Giacosa, Italy
| | - Martina Capozza
- Center for Preclinical Imaging, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Ribes 5, Colleretto Giacosa, Italy
| | - Dario Livio Longo
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy. .,Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Via Nizza 52, Turin, Italy.
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12
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Moshafi MH, Ranjbar M, Ilbeigi G. Eco-Friendly and Systematic Study for Synthesis of La 3+/α-Al 2O 3 Nanoparticles: Antibacterial Activity Against Pathogenic Microbial Strains. Int J Nanomedicine 2020; 14:10137-10146. [PMID: 31920309 PMCID: PMC6941601 DOI: 10.2147/ijn.s215372] [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: 05/11/2019] [Accepted: 09/18/2019] [Indexed: 11/23/2022] Open
Abstract
Purpose In this study, for the first time, new nanoparticles of La3+/α-Al2O3 were synthesized with the ultrasonic-assisted hydrothermal method in the presence of honey as an eco-friendly and natural reagent. Methods The as-synthesized La3+/α-Al2O3 nanoparticles were characterized using scanning electron microscopy (SEM), transition electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), energy dispersive X-ray (EDX), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. In this work, we report optimum conditions to synthesize La3+/α-Al2O3 nanoparticles as novel material and as a candidate for antibacterial activity in antibacterial drugs. Results and Conclusion The XRD and SEM micrograph results demonstrate the formation of pure La3+/α-Al2O3 nanoparticles with a particle size in the range of 30-80 nm. The synthesis parameters were systematically examined using analysis of variance (ANOVA) through 2k-1 factorial design, and the factors were an assay for product optimization. Various factors such as hydrothermal time, temperature, ultrasound irradiation and interaction between these factors were investigated on the product size of the products. To investigate antibacterial activity of the La3+/α-Al2O3 nanoparticles with the minimum inhibitory concentration (MIC) method, different dilutions of nanoparticles as 64, 32, 16, 8, 4, 2, 1 and 0.5 μg/mL were dissolved in dimethyl sulfoxide and diluted using distilled water and added to the Mueller-Hinton agar medium containing Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Serratia marcescens as gram-negative bacteria and Bacillus subtilis, Staphylococcus aureus, S. epidermidis and Micrococcus luteus as gram-positive bacteria.
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Affiliation(s)
- Mohammad Hasan Moshafi
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mehdi Ranjbar
- Food Drug and Cosmetics Safety Research Center Kerman University of Medical Sciences, Kerman, Iran.,Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Ghazaleh Ilbeigi
- Student Research Committee, Kerman University of Medical Sciences, Kerman, Iran
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13
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14
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Dastrù W, Menchise V, Ferrauto G, Fabretto S, Carrera C, Terreno E, Aime S, Castelli DD. Modulation of the Prototropic Exchange Rate in pH-Responsive Yb-HPDO3A Derivatives as ParaCEST Agents. ChemistrySelect 2018. [DOI: 10.1002/slct.201800283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Walter Dastrù
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
| | - Valeria Menchise
- Istituto di Biostrutture e Bioimmagini; Consiglio Nazionale delle Ricerche; via Mezzocannone 16 80134 Napoli Italy
| | - Giuseppe Ferrauto
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
| | - Serena Fabretto
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
| | - Carla Carrera
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
| | - Enzo Terreno
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
| | - Silvio Aime
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
| | - Daniela Delli Castelli
- Department of Molecular Biotechnology and Health Sciences; Molecular Imaging Center; University of Torino; Via Nizza 52 10126 Torino Italy
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15
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Tsitovich PB, Tittiris TY, Cox JM, Benedict JB, Morrow JR. Fe(ii) and Co(ii) N-methylated CYCLEN complexes as paraSHIFT agents with large temperature dependent shifts. Dalton Trans 2018; 47:916-924. [PMID: 29260180 DOI: 10.1039/c7dt03812g] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Several complexes of Co(ii) or Fe(ii) with 1,4,7,10-tetraazacyclododecane (CYCLEN) appended with 1,7-(6-methyl)2-picolyl groups are studied as 1H NMR paraSHIFT agents (paramagnetic shift agents) for the registration of temperature. Two of the complexes, [Co(BMPC)]2+ and [Fe(BMPC)]2+, contain methyl groups only on the methyl picolyl pendents. Two other complexes, [Co(2MPC)]2+ and [Fe(2MPC)]2+, contain picolyl groups and also methyl groups on the macrocyclic amines. All macrocyclic complexes are in high spin form as shown by solution magnetic moments in the range of 5.0-5.9μBM and 5.3-5.8μBM for Co(ii) and Fe(ii) complexes, respectively. The 1H NMR spectra of both of the Fe(ii) complexes and one of the Co(ii) complexes are consistent with a predominant diastereomeric form in deuterium oxide solutions. The highly shifted methyl proton resonances for [Co(2MPC)]2+ appear at 164 and -113 ppm for macrocycle and pendent picolyl methyls and show temperature coefficients of -0.58 ppm °C-1 and 0.49 ppm °C-1, respectively. Fe(ii) complexes have less shifted methyl proton resonances and smaller temperature coefficients. The 1H resonances of [Fe(2MPC)]2+ appear at 105 ppm and -46 ppm with corresponding temperature coefficients (CT) of -0.29 ppm °C-1 and 0.22 ppm °C-1, respectively. The relatively narrow linewidths of [Fe(2MPC)]2+, however, produce superior CT/FWHM values of 0.44 and 0.31 °C-1 for the N-methyl and picolyl proton resonances where FWHM is the full width at half maximum of the 1H resonance. The crystal structure of [Co(BMPC)]Cl2 shows a six-coordinate Co(ii) bound to the macrocyclic amines and two pendent picolyl groups. The distorted trigonal prismatic geometry of the complex resembles that of an analogous complex containing four 6-methyl-2-picolyl groups, in which only two picolyl pendents are coordinated.
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Affiliation(s)
- Pavel B Tsitovich
- Department of Chemistry, University at Buffalo, State University of New York, Amherst, NY 14260, USA.
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16
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Abstract
Metabolism is central to neuroimaging because it can reveal pathways by which neuronal and glial cells use nutrients to fuel their growth and function. We focus on advanced magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) methods used in brain metabolic studies. 17O-MRS and 31P-MRS, respectively, provide rates of oxygen use and ATP synthesis inside mitochondria, whereas 19F-MRS enables measurement of cytosolic glucose metabolism. Calibrated functional MRI (fMRI), an advanced form of fMRI that uses contrast generated by deoxyhemoglobin, provides maps of oxygen use that track neuronal firing across brain regions. 13C-MRS is the only noninvasive method of measuring both glutamatergic neurotransmission and cell-specific energetics with signaling and nonsignaling purposes. Novel MRI contrasts, arising from endogenous diamagnetic agents and exogenous paramagnetic agents, permit pH imaging of glioma. Overall, these magnetic resonance methods for imaging brain metabolism demonstrate translational potential to better understand brain disorders and guide diagnosis and treatment.
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Affiliation(s)
- Fahmeed Hyder
- Department of Biomedical Engineering, Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, and Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, Connecticut 06520;
| | - Douglas L Rothman
- Department of Biomedical Engineering, Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, and Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, Connecticut 06520;
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17
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Singh J, Rustagi V, Zhang S, Sherry AD, Udugamasooriya DG. On-bead combinatorial synthesis and imaging of europium(III)-based paraCEST agents aids in identification of chemical features that enhance CEST sensitivity. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:747-753. [PMID: 28220538 PMCID: PMC5501467 DOI: 10.1002/mrc.4588] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/15/2017] [Accepted: 02/16/2017] [Indexed: 05/08/2023]
Abstract
The rate of water exchange between the inner sphere of a paramagnetic ion and bulk water is an important parameter in determining the magnitude of the chemical exchange saturation transfer signal from paramagnetic CEST agents (paraCEST). This is governed by various geometric, steric and ligand field factors created by macrocyclic ligands surrounding the paramagnetic metal ion. Our previous on-bead combinatorial studies of di-peptoid-europium(III)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-tetraamide complexes revealed that negatively charged groups in the immediate vicinity of the metal center strongly enhances the CEST signal. Here, we report a solid phase synthesis and on-bead imaging of 76 new DOTA derivatives that are developed by coupling with a single residue onto each of the three arms of a DOTA-tetraamide scaffold attached to resin beads. This single residue predominantly carries negatively charged groups blended with various physico-chemical characteristics. We found that non-bulky negatively charged groups are best suited at the immediate vicinity of the metal ion, while positive, bulky and halogen containing moieties suppress the CEST signal. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jaspal Singh
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd, Houston, TX, 77204-5037, USA
| | - Vineeta Rustagi
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd, Houston, TX, 77204-5037, USA
| | - Shanrong Zhang
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-8568, USA
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390-8568, USA
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Rd, Richardson, TX, 75083-3021, USA
| | - D Gomika Udugamasooriya
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, 3455 Cullen Blvd, Houston, TX, 77204-5037, USA
- Department of Cancer Systems Imaging, MD Anderson Cancer Center, 1881 East Road, Houston, TX, 77030-4009, USA
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18
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Krchová T, Herynek V, Gálisová A, Blahut J, Hermann P, Kotek J. Eu(III) Complex with DO3A-amino-phosphonate Ligand as a Concentration-Independent pH-Responsive Contrast Agent for Magnetic Resonance Spectroscopy (MRS). Inorg Chem 2017; 56:2078-2091. [PMID: 28170242 DOI: 10.1021/acs.inorgchem.6b02749] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new DOTA-like ligand H5do3aNP with a 2-[amino(methylphosphonic acid)]ethyl-coordinating pendant arm was prepared, and its coordinating properties were studied by NMR spectroscopy and potentiometry. The study revealed a rare slow exchange (on the 1H and 31P NMR time scale) between protonated and unprotonated complex species with a corresponding acidity constant pKA ∼ 8.0. This unusually slow time scale associated with protonation is caused by a significant geometric change from square-antiprismatic (SA) arrangement observed for protonated complex SA-[Eu(Hdo3aNP)]- to twisted-square-antiprismatic (TSA) arrangement found for deprotonated complex TSA-[Eu(do3aNP)]2-. This behavior results in simultaneous occurrence of the signals of both species in the 31P NMR spectra at approximately -118 and +70 ppm, respectively. Such an unprecedented difference in the chemical shifts between species differing by a proton is caused by a significant movement of the principal magnetic axis and by a change of phosphorus atom position in the coordination sphere of the central Eu(III) ion (i.e., by relative movement of the phosphorus atom with respect to the principal magnetic axis). It changes the sign of the paramagnetic contribution to the 31P NMR chemical shift. The properties discovered can be employed in the measurement of pH by MRS techniques as presented by proof-of-principle experiments on phantoms.
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Affiliation(s)
- Tereza Krchová
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Vít Herynek
- Department of Radiodiagnostic and Interventional Radiology, Magnetic Resonance Unit, Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, Prague 4 140 21, Czech Republic
| | - Andrea Gálisová
- Department of Radiodiagnostic and Interventional Radiology, Magnetic Resonance Unit, Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, Prague 4 140 21, Czech Republic
| | - Jan Blahut
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Petr Hermann
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Jan Kotek
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
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19
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Abadjian MCZ, Edwards WB, Anderson CJ. Imaging the Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1036:229-257. [PMID: 29275475 DOI: 10.1007/978-3-319-67577-0_15] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The tumor microenvironment consists of tumor, stromal, and immune cells, as well as extracellular milieu. Changes in numbers of these cell types and their environments have an impact on cancer growth and metastasis. Non-invasive imaging of aspects of the tumor microenvironment can provide important information on the aggressiveness of the cancer, whether or not it is metastatic, and can also help to determine early response to treatment. This chapter provides an overview on non-invasive in vivo imaging in humans and mouse models of various cell types and physiological parameters that are unique to the tumor microenvironment. Current clinical imaging and research investigation are in the areas of nuclear imaging (positron emission tomography (PET) and single photon emission computed tomography (SPECT)), magnetic resonance imaging (MRI) and optical (near infrared (NIR) fluorescence) imaging. Aspects of the tumor microenvironment that have been imaged by PET, MRI and/or optical imaging are tumor associated inflammation (primarily macrophages and T cells), hypoxia, pH changes, as well as enzymes and integrins that are highly prevalent in tumors, stroma and immune cells. Many imaging agents and strategies are currently available for cancer patients; however, the investigation of novel avenues for targeting aspects of the tumor microenvironment in pre-clinical models of cancer provides the cancer researcher with a means to monitor changes and evaluate novel treatments that can be translated into the clinic.
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Affiliation(s)
| | - W Barry Edwards
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carolyn J Anderson
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
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20
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Strickland M, Schwieters CD, Göbl C, Opina ACL, Strub MP, Swenson RE, Vasalatiy O, Tjandra N. Characterizing the magnetic susceptibility tensor of lanthanide-containing polymethylated-DOTA complexes. JOURNAL OF BIOMOLECULAR NMR 2016; 66:125-139. [PMID: 27659040 PMCID: PMC6628275 DOI: 10.1007/s10858-016-0061-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 09/13/2016] [Indexed: 05/16/2023]
Abstract
Lanthanide complexes based on the DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) cage are commonly used as phase contrast agents in magnetic resonance imaging, but can also be utilized in structural NMR applications due to their ability to induce either paramagnetic relaxation enhancement or a pseudocontact shift (PCS) depending on the choice of the lanthanide. The size and sign of the PCS for any given atom is determined by its coordinates relative to the metal center, and the characteristics of the lanthanide's magnetic susceptibility tensor. Using a polymethylated DOTA tag (Ln-M8-SPy) conjugated to ubiquitin, we calculated the position of the metal center and characterized the susceptibility tensor for a number of lanthanides (dysprosium, thulium, and ytterbium) under a range of pH and temperature conditions. We found that there was a difference in temperature sensitivity for each of the complexes studied, which depended on the size of the lanthanide ion as well as the isomeric state of the cage. Using 17O-NMR, we confirmed that the temperature sensitivity of the compounds was enhanced by the presence of an apically bound water molecule. Since amide-containing lanthanide complexes are known to be pH sensitive and can be used as probes of physiological pH, we also investigated the effect of pH on the Ln-M8-SPy susceptibility tensor, but we found that the changes in this pH range (5.0-7.4) were not significant.
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Affiliation(s)
- Madeleine Strickland
- Laboratory of Molecular Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Charles D Schwieters
- Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Christoph Göbl
- Department of Chemistry, Technische Universität München, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Ana C L Opina
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD, 20850, USA
| | - Marie-Paule Strub
- Laboratory of Molecular Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Rolf E Swenson
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD, 20850, USA
| | - Olga Vasalatiy
- Imaging Probe Development Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD, 20850, USA
| | - Nico Tjandra
- Laboratory of Molecular Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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21
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Huang Y, Coman D, Herman P, Rao JU, Maritim S, Hyder F. Towards longitudinal mapping of extracellular pH in gliomas. NMR IN BIOMEDICINE 2016; 29:1364-1372. [PMID: 27472471 PMCID: PMC5035200 DOI: 10.1002/nbm.3578] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/06/2016] [Accepted: 06/07/2016] [Indexed: 06/06/2023]
Abstract
Biosensor imaging of redundant deviation in shifts (BIRDS), an ultrafast chemical shift imaging technique, requires infusion of paramagnetic probes such as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis methylene phosphonate (DOTP(8-) ) complexed with thulium (Tm(3+) ) ion (i.e. TmDOTP(5-) ), where the pH-sensitive resonances of hyperfine-shifted non-exchangeable protons contained within the paramagnetic probe are detected. While imaging extracellular pH (pHe ) with BIRDS meets an important cancer research need by mapping the intratumoral-peritumoral pHe gradient, the surgical intervention used to raise the probe's plasma concentration limits longitudinal scans on the same subject. Here we describe using probenecid (i.e. an organic anion transporter inhibitor) to temporarily restrict renal clearance of TmDOTP(5-) , thereby facilitating molecular imaging by BIRDS without surgical intervention. Co-infusion of probenecid with TmDOTP(5-) increased the probe's distribution into various organs, including the brain, compared with infusing TmDOTP(5-) alone. In vivo BIRDS data using the probenecid-TmDOTP(5-) co-infusion method in rats bearing RG2, 9 L, and U87 brain tumors showed intratumoral-peritumoral pHe gradients that were unaffected by the probe dose. This co-infusion method can be used for pHe mapping with BIRDS in preclinical models for tumor characterization and therapeutic monitoring, given the possibility of repeated scans with BIRDS (e.g. over days and even weeks) in the same subject. The longitudinal pHe readout by the probenecid-TmDOTP(5-) co-infusion method for BIRDS adds translational value in tumor assessment and treatment. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Yuegao Huang
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA.
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA.
| | - Daniel Coman
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Peter Herman
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Jyotsna U Rao
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Samuel Maritim
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Fahmeed Hyder
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA.
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, USA.
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
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22
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Jiang W, Zhou IY, Wen L, Zhou X, Sun PZ. A theoretical analysis of chemical exchange saturation transfer echo planar imaging (CEST-EPI) steady state solution and the CEST sensitivity efficiency-based optimization approach. CONTRAST MEDIA & MOLECULAR IMAGING 2016; 11:415-423. [PMID: 27312932 DOI: 10.1002/cmmi.1699] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 04/27/2016] [Accepted: 05/02/2016] [Indexed: 11/11/2022]
Abstract
Chemical exchange saturation transfer (CEST) MRI is sensitive to dilute labile protons and microenvironmental properties, augmenting routine relaxation-based MRI. Recent developments of quantitative CEST (qCEST) analysis such as omega plots and RF-power based ratiometric calculation have extended our ability to elucidate the underlying CEST system beyond the simplistic apparent CEST measurement. CEST MRI strongly varies with experimental factors, including the RF irradiation level and duration as well as repetition time and flip angle. In addition, the CEST MRI effect is typically small, and experimental optimization strategies have to be carefully evaluated in order to enhance the CEST imaging sensitivity. Although routine CEST MRI has been optimized largely based on maximizing the magnitude of the CEST effect, the CEST signal-to-noise (SNR) efficiency provides a more suitable optimization index, particularly when the scan time is constrained. Herein, we derive an analytical solution of the CEST effect that takes into account key experimental parameters including repetition time, imaging flip angle and RF irradiation level, and solve its SNR efficiency. The solution expedites CEST imaging sensitivity calculation, substantially faster than the Bloch-McConnell equation-based numerical simulation approach. In addition, the analytical solution-based SNR formula enables the exhaustive optimization of CEST MRI, which simultaneously predicts multiple optimal parameters such as repetition time, flip angle and RF saturation level based on the chemical shift and exchange rate. The sensitivity efficiency-based optimization approach could simplify and guide imaging of CEST agents, including glycogen, glucose, creatine, gamma-aminobutyric acid and glutamate. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Weiping Jiang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.,State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China
| | - Iris Yuwen Zhou
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Lingyi Wen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Xin Zhou
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China.
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA. .,Department of Radiology, University of Illinois at Chicago, IL, USA.
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23
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Castro G, Regueiro-Figueroa M, Esteban-Gómez D, Pérez-Lourido P, Platas-Iglesias C, Valencia L. Magnetic Anisotropies in Rhombic Lanthanide(III) Complexes Do Not Conform to Bleaney’s Theory. Inorg Chem 2016; 55:3490-7. [DOI: 10.1021/acs.inorgchem.5b02918] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Goretti Castro
- Departamento de Química Inorgánica,
Facultad de Ciencias, Universidade de Vigo, As Lagoas, Pontevedra, Marcosende 36310, Spain
| | - Martín Regueiro-Figueroa
- Centro
de Investigaciones Científicas Avanzadas (CICA) and Departamento de Química Fundamental, 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 Fundamental, 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, Pontevedra, Marcosende 36310, Spain
| | - Carlos Platas-Iglesias
- Centro
de Investigaciones Científicas Avanzadas (CICA) and Departamento de Química Fundamental, 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, Pontevedra, Marcosende 36310, Spain
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24
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Coman D, Huang Y, Rao JU, De Feyter HM, Rothman DL, Juchem C, Hyder F. Imaging the intratumoral-peritumoral extracellular pH gradient of gliomas. NMR IN BIOMEDICINE 2016; 29:309-19. [PMID: 26752688 PMCID: PMC4769673 DOI: 10.1002/nbm.3466] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/19/2015] [Accepted: 11/19/2015] [Indexed: 05/26/2023]
Abstract
Solid tumors have an acidic extracellular pH (pHe ) but near neutral intracellular pH (pHi ). Because acidic pHe milieu is conducive to tumor growth and builds resistance to therapy, simultaneous mapping of pHe inside and outside the tumor (i.e., intratumoral-peritumoral pHe gradient) fulfills an important need in cancer imaging. We used Biosensor Imaging of Redundant Deviation in Shifts (BIRDS), which utilizes shifts of non-exchangeable protons from macrocyclic chelates (e.g., 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylene phosphonate) or DOTP(8-) ) complexed with paramagnetic thulium (Tm(3) (+) ) ion, to generate in vivo pHe maps in rat brains bearing 9L and RG2 tumors. Upon TmDOTP(5-) infusion, MRI identified the tumor boundary by enhanced water transverse relaxation and BIRDS allowed imaging of intratumoral-peritumoral pHe gradients. The pHe measured by BIRDS was compared with pHi measured with (31) P-MRS. In normal tissue, pHe was similar to pHi , but inside the tumor pHe was lower than pHi . While the intratumoral pHe was acidic for both tumor types, peritumoral pHe varied with tumor type. The intratumoral-peritumoral pHe gradient was much larger for 9L than RG2 tumors because in RG2 tumors acidic pHe was found in distal peritumoral regions. The increased presence of Ki-67 positive cells beyond the RG2 tumor border suggested that RG2 was more invasive than the 9L tumor. These results indicate that extensive acidic pHe beyond the tumor boundary correlates with tumor cell invasion. In summary, BIRDS has sensitivity to map the in vivo intratumoral-peritumoral pHe gradient, thereby creating preclinical applications in monitoring cancer therapeutic responses (e.g., with pHe -altering drugs). Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Daniel Coman
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Yuegao Huang
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Jyotsna U. Rao
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Henk M. De Feyter
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
| | - Douglas L. Rothman
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Christoph Juchem
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
- Department of Neurology, Yale University, New Haven, CT, USA
| | - Fahmeed Hyder
- Magnetic Resonance Research Center, Yale University, New Haven, CT, USA
- Department of Diagnostic Radiology, Yale University, New Haven, CT, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
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Tsitovich PB, Cox JM, Benedict JB, Morrow JR. Six-coordinate Iron(II) and Cobalt(II) paraSHIFT Agents for Measuring Temperature by Magnetic Resonance Spectroscopy. Inorg Chem 2016; 55:700-16. [PMID: 26716610 PMCID: PMC5555598 DOI: 10.1021/acs.inorgchem.5b02144] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Paramagnetic Fe(II) and Co(II) complexes are utilized as the first transition metal examples of (1)H NMR shift agents (paraSHIFT) for thermometry applications using Magnetic Resonance Spectroscopy (MRS). The coordinating ligands consist of TACN (1,4,7-triazacyclononane) and CYCLEN (1,4,7,10-tetraazacyclododecane) azamacrocycles appended with 6-methyl-2-picolyl groups, denoted as MPT and TMPC, respectively. (1)H NMR spectra of the MPT- and TMPC-based Fe(II) and Co(II) complexes demonstrate narrow and highly shifted resonances that are dispersed as broadly as 440 ppm. The six-coordinate complex cations, [M(MPT)](2+) and [M(TMPC)](2+), vary from distorted octahedral to distorted trigonal prismatic geometries, respectively, and also demonstrate that 6-methyl-2-picolyl pendents control the rigidity of these complexes. Analyses of the (1)H NMR chemical shifts, integrated intensities, line widths, the distances obtained from X-ray diffraction measurements, and longitudinal relaxation time (T1) values allow for the partial assignment of proton resonances of the [M(MPT)](2+) complexes. Nine and six equivalent methyl protons of [M(MPT)](2+) and [M(TMPC)](2+), respectively, produce 3-fold higher (1)H NMR intensities compared to other paramagnetically shifted proton resonances. Among all four complexes, the methyl proton resonances of [Fe(TMPC)](2+) and [Co(TMPC)](2+) at -49.3 ppm and -113.7 ppm (37 °C) demonstrate the greatest temperature dependent coefficients (CT) of 0.23 ppm/°C and 0.52 ppm/°C, respectively. The methyl groups of these two complexes both produce normalized values of |CT|/fwhm = 0.30 °C(-1), where fwhm is full width at half-maximum (Hz) of proton resonances. The T1 values of the highly shifted methyl protons are in the range of 0.37-2.4 ms, allowing rapid acquisition of spectroscopic data. These complexes are kinetically inert over a wide range of pH values (5.6-8.6), as well as in the presence of serum albumin and biologically relevant cations and anions. The combination of large hyperfine shifts, large temperature sensitivity, increased signal-to-noise ratio, and short T1 values suggests that these complexes, in particular the TMPC-based complexes, show promise as paraSHIFT agents for thermometry.
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Affiliation(s)
- Pavel B. Tsitovich
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260
| | - Jordan M. Cox
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260
| | - Jason B. Benedict
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260
| | - Janet R. Morrow
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260
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Castro G, Regueiro-Figueroa M, Esteban-Gómez D, Bastida R, Macías A, Pérez-Lourido P, Platas-Iglesias C, Valencia L. Exceptionally Inert Lanthanide(III) PARACEST MRI Contrast Agents Based on an 18-Membered Macrocyclic Platform. Chemistry 2015; 21:18662-70. [DOI: 10.1002/chem.201502937] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 11/10/2022]
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Huang Y, Coman D, Hyder F, Ali MM. Dendrimer-Based Responsive MRI Contrast Agents (G1-G4) for Biosensor Imaging of Redundant Deviation in Shifts (BIRDS). Bioconjug Chem 2015; 26:2315-23. [PMID: 26497087 DOI: 10.1021/acs.bioconjchem.5b00568] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Biosensor imaging of redundant deviation in shifts (BIRDS) is a molecular imaging platform for magnetic resonance that utilizes unique properties of low molecular weight paramagnetic monomers by detecting hyperfine-shifted nonexchangeable protons and transforming the chemical shift information to reflect its microenvironment (e.g., via temperature, pH, etc.). To optimize translational biosensing potential of BIRDS we examined if this detection scheme observed with monomers can be extended onto dendrimers, which are versatile and biocompatible macromolecules with modifiable surface for molecular imaging and drug delivery. Here we report on feasibility of paramagnetic dendrimers for BIRDS. The results show that BIRDS is resilient with paramagnetic dendrimers up to the fourth generation (i.e., G1-G4), where the model dendrimer and chelate were based on poly(amido amine) (PAMAM) and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA(4-)) complexed with thulium ion (Tm(3+)). Temperature sensitivities of two prominent signals of Gn-PAMAM-(TmDOTA(-))x (where n = 1-4, x = 6-39) were comparable to that of prominent signals in TmDOTA(-). Transverse relaxation times of the coalesced nonexchangeable protons on Gn-PAMAM-(TmDOTA(-))x were relatively short to provide signal-to-noise ratio that was comparable to or better than that of TmDOTA(-). A fluorescent dye, rhodamine, was conjugated to a G2-PAMAM-(TmDOTA)12 to create a dual-modality nanosized contrast agent. BIRDS properties of the dendrimer were unaltered with rhodamine conjugation. Purposely designed paramagnetic dendrimers for BIRDS in conjunction with novel macromolecular surface modification for functional ligands/drugs could potentially be used for biologically compatible theranostic sensors.
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Affiliation(s)
| | | | | | - Meser M Ali
- Department of Neurology, Henry Ford Hospital , Detroit, Michigan 48202, United States
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28
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Kim J, Wu Y, Guo Y, Zheng H, Sun PZ. A review of optimization and quantification techniques for chemical exchange saturation transfer MRI toward sensitive in vivo imaging. CONTRAST MEDIA & MOLECULAR IMAGING 2015; 10:163-178. [PMID: 25641791 DOI: 10.1002/cmmi.1628] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/26/2014] [Accepted: 09/10/2014] [Indexed: 01/10/2023]
Abstract
Chemical exchange saturation transfer (CEST) MRI is a versatile imaging method that probes the chemical exchange between bulk water and exchangeable protons. CEST imaging indirectly detects dilute labile protons via bulk water signal changes following selective saturation of exchangeable protons, which offers substantial sensitivity enhancement and has sparked numerous biomedical applications. Over the past decade, CEST imaging techniques have rapidly evolved owing to contributions from multiple domains, including the development of CEST mathematical models, innovative contrast agent designs, sensitive data acquisition schemes, efficient field inhomogeneity correction algorithms, and quantitative CEST (qCEST) analysis. The CEST system that underlies the apparent CEST-weighted effect, however, is complex. The experimentally measurable CEST effect depends not only on parameters such as CEST agent concentration, pH and temperature, but also on relaxation rate, magnetic field strength and more importantly, experimental parameters including repetition time, RF irradiation amplitude and scheme, and image readout. Thorough understanding of the underlying CEST system using qCEST analysis may augment the diagnostic capability of conventional imaging. In this review, we provide a concise explanation of CEST acquisition methods and processing algorithms, including their advantages and limitations, for optimization and quantification of CEST MRI experiments.
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Affiliation(s)
- Jinsuh Kim
- Department of Radiology, University of Iowa, Iowa City, IA, USA
| | - Yin Wu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yingkun Guo
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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29
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Maritim S, Huang Y, Coman D, Hyder F. Characterization of a lanthanide complex encapsulated with MRI contrast agents into liposomes for biosensor imaging of redundant deviation in shifts (BIRDS). J Biol Inorg Chem 2014; 19:1385-98. [PMID: 25304046 DOI: 10.1007/s00775-014-1200-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 09/23/2014] [Indexed: 12/24/2022]
Abstract
Purposely designed magnetic resonance imaging (MRI) probes encapsulated in liposomes, which alter contrast by their paramagnetic effect on longitudinal (T₁) and transverse (T₂) relaxation times of tissue water, hold promise for molecular imaging. However, a challenge with liposomal MRI probes that are solely dependent on enhancement of water relaxation is lack of specific molecular readouts, especially in strong paramagnetic environments, thereby reducing the potential for monitoring disease treatment (e.g., cancer) beyond the generated MRI contrast. Previously, it has been shown that molecular imaging with magnetic resonance is also possible by detecting the signal of non-exchangeable protons emanating from paramagnetic lanthanide complexes themselves [e.g., TmDOTP⁵⁻, which is a Tm³⁺ -containing biosensor based on a macrocyclic chelate 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylene phosphonate), DOTP⁵⁻] with a method called biosensor imaging of redundant deviation in shifts (BIRDS). Here, we show that BIRDS is useful for molecular imaging with probes like TmDOTP⁵⁻ even when they are encapsulated inside liposomes with ultrastrong T₁and T₂contrast agents (e.g., Magnevist and Molday ION, respectively). We demonstrate that molecular readouts such as pH and temperature determined from probes like TmDOTP⁵⁻ are resilient, because the sensitivity of the chemical shifts to the probe's environment is not compromised by the presence of other paramagnetic agents contained within the same nanocarrier milieu. Because high liposomal encapsulation efficiency allows for robust MRI contrast and signal amplification for BIRDS, nanoengineered liposomal probes containing both monomers, TmDOTP⁵⁻ and paramagnetic contrast agents, could allow high spatial resolution imaging of disease diagnosis (with MRI) and status monitoring (with BIRDS).
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Affiliation(s)
- Samuel Maritim
- Department of Biomedical Engineering, Yale University, New Haven, CT, 06520, USA,
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