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Alonso Martinez LM, Harel F, Nguyen QT, Létourneau M, D'Oliviera-Sousa C, Meloche B, Finnerty V, Fournier A, Dupuis J, DaSilva JN. Al[ 18F]F-complexation of DFH17, a NOTA-conjugated adrenomedullin analog, for PET imaging of pulmonary circulation. Nucl Med Biol 2018; 67:36-42. [PMID: 30388434 DOI: 10.1016/j.nucmedbio.2018.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/01/2018] [Accepted: 10/11/2018] [Indexed: 01/06/2023]
Abstract
INTRODUCTION Adrenomedullin receptors are highly expressed in human alveolar capillaries and provide a molecular target for imaging the integrity of pulmonary microcirculation. In this work, we aimed to develop a NOTA-derivatized adrenomedullin analog (DFH17), radiolabeled with [18F]AlF, for PET imaging of pulmonary microcirculation. METHODS Highly concentrated [18F](AlF)2+ (15 μL) was produced from purified fluorine-18 in NaCl 0.9%. Various complexation experiments were carried out at Al-to-NOTA molar ratios ranging from 1:1 to 1:40 to assess optimal radiolabeling conditions before using the peptide. DFH17 peptide (2 mM, pH 4) was radiolabeled with [18F](AlF)2+ for 15 min at 100 °C in a total volume of 60 μL. As part of the radiolabeling process, parameters such as fluorine-18 activity (~37 and 1480 MBq), concentration of AlCl3 (0.75, 2, 3, 6 or 10 mM) and the effects of hydrophilic organic solvent (aqueous vs ethanol 50%) were studied. The final formulation was tested for purity, identity and stability in saline. Initial in vivo evaluation of [18F]AlF-DFH17 was performed in normal rats by PET/CT. RESULTS The scaled-up production of [18F]AlF-DFH17 was performed in high radiochemical and chemical purities in an overall radiochemical yield of 22-38% (at end-of-synthesis) within 60 min. The final formulation was stable in saline at different radioactive concentrations for 8 h. PET evaluation in rats revealed high lung-to-background ratios and no defluorination in vivo up to 1 h post-injection. CONCLUSION The novel radioconjugate [18F]AlF-DFH17 appears to be a promising PET ligand for pulmonary microcirculation imaging.
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Affiliation(s)
- Luis Michel Alonso Martinez
- University of Montreal Hospital Research Centre, 900 rue Saint-Denis, Montréal, Québec H2X 3H8, Canada; Department of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960 chemin de la Tour, Montréal, Québec H3T 1J4, Canada; Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada
| | - François Harel
- Department of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960 chemin de la Tour, Montréal, Québec H3T 1J4, Canada; Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada; Department of Radiology, Radio-oncology and Nuclear Medicine, Université de Montréal, Pavillon Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - Quang T Nguyen
- Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada
| | - Myriam Létourneau
- Laboratoire D'études Moléculaires et Pharmacologiques des Peptides, INRS-Institut Armand-Frappier, 531 boulevard des Prairies, Laval, Québec H7V 1B7, Canada
| | - Caroline D'Oliviera-Sousa
- Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada
| | - Bernard Meloche
- Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada
| | - Vincent Finnerty
- Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada
| | - Alain Fournier
- Department of Radiology, Radio-oncology and Nuclear Medicine, Université de Montréal, Pavillon Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - Jocelyn Dupuis
- Research Center of the Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec H1T 1C8, Canada; Department of Medicine, Université de Montréal, 2900 boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada
| | - Jean N DaSilva
- University of Montreal Hospital Research Centre, 900 rue Saint-Denis, Montréal, Québec H2X 3H8, Canada; Department of Biomedical Engineering, Faculty of Medicine, Université de Montréal, Pavillon Paul-G. Desmarais, 2960 chemin de la Tour, Montréal, Québec H3T 1J4, Canada; Department of Radiology, Radio-oncology and Nuclear Medicine, Université de Montréal, Pavillon Roger-Gaudry, 2900 Boulevard Edouard Montpetit, Montréal, Québec H3T 1J4, Canada.
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