1
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Veth L, Windhorst AD, Vugts DJ. Synthesis of 18F-labelled aryl trifluoromethyl ketones with improved molar activity. Chem Commun (Camb) 2024; 60:6801-6804. [PMID: 38869169 DOI: 10.1039/d4cc01776e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
A method for the radiosynthesis of 18F-labelled aryl trifluoromethyl ketones starting from widely available Weinreb amides using [18F]fluoroform is presented. The method uses potassium hexamethyldisilazane as base and delivers products in high molar activity (up to 24 GBq μmol-1) and excellent radiochemical conversions. The applicability for PET tracer synthesis is demonstrated by the radiosynthesis of ten (hetero)aryl trifluoromethylketones, bearing electron-withdrawing and -donating substituents including a derivative of bioactive probenecid.
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Affiliation(s)
- Lukas Veth
- Dept. of Radiology & Nuclear Medicine Amsterdam UMC, Location Vrije Universiteit Amsterdam De Boelelaan, 1117, Amsterdam, The Netherlands.
| | - Albert D Windhorst
- Dept. of Radiology & Nuclear Medicine Amsterdam UMC, Location Vrije Universiteit Amsterdam De Boelelaan, 1117, Amsterdam, The Netherlands.
| | - Danielle J Vugts
- Dept. of Radiology & Nuclear Medicine Amsterdam UMC, Location Vrije Universiteit Amsterdam De Boelelaan, 1117, Amsterdam, The Netherlands.
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2
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Maqbool M, Jakobsson JE, Alluri SR, Kramer V, Riss PJ. A protocol for controlled reactivity shift in the 2,2-difluorovinyl motif used for selective S- 18F and C- 18F bond formation. Commun Chem 2024; 7:97. [PMID: 38684771 PMCID: PMC11058245 DOI: 10.1038/s42004-024-01132-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/20/2024] [Indexed: 05/02/2024] Open
Abstract
Positron emission tomography (PET) is a powerful imaging technique for biomedical research, drug development and medical diagnosis. The power of PET lies in biochemically selective radiotracers, labelled with positron emitters like fluorine-18 image chemical processes in vivo. A rapid and remarkably efficient, unprecedented protocol to select between S-F and C-F bond formation based on activation of 1,1-difluoroethylene groups followed by selective oxidation or reduction is described. While transition metal mediated conditions can be employed, the reaction proceeds in high yield using unobjectionable chemical reagents amenable to routine radiotracer production. The latter bodes well for facile clinical translation of the method. The new technique affords radiotracers and the labelling reagent 2,2-difluoro-2-(fluoro-18F)ethyl 4-methylbenzenesulfonate ([18F]1b) in excellent yield. Following oxygenation of the reaction mixture with medical oxygen or air, sulfonyl fluorides are obtained as the primary product. The new protocol was employed in a proof of principle to develop a radiometric assay for quantitation of sulfonylation yield with sulfonyl fluoride reagents. With operational ease and mild conditions, the method bodes a high potential for radiolabelling of biomolecules, known enzyme inhibitors and other temperature-sensitive compounds.
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Affiliation(s)
- Mudasir Maqbool
- Department of Clinical Neurocience, OUS-Ullevål, Oslo, Norway
- Department of Chemistry, University of Oslo, Oslo, Norway
| | | | | | - Vasko Kramer
- Positronpharma SA, Rancangua, Santiago de Chile, Santiago, Chile
| | - Patrick Johannes Riss
- Department of Clinical Neurocience, OUS-Ullevål, Oslo, Norway.
- Department of Chemistry, University of Oslo, Oslo, Norway.
- Department of Chemistry, Johannes Gutenberg-University, Fritz-Strassmann-Weg 2, 55128, Mainz, Germany.
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3
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Lu Y, He Y, Schibli R, Mu L, van Dam RM. Proof-of-concept optimization of a copper-mediated 18F-radiosynthesis of a novel MAGL PET tracer on a high-throughput microdroplet platform and its macroscale translation. LAB ON A CHIP 2023; 23:4652-4663. [PMID: 37818614 PMCID: PMC10608794 DOI: 10.1039/d3lc00735a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
Copper-mediated radiofluorination has demonstrated remarkable potential in forming aromatic C-18F bonds of radioligands for positron emission tomography (PET). Achieving optimal results often requires optimization efforts, requiring a substantial amount of radiolabeling precursor and time, severely limiting the experimental throughput. Recently, we successfully showcased the feasibility of performing and optimizing Cu-mediated radiosynthesis on a high-throughput microdroplet platform using the well-known and clinically used radioligand [18F]FDOPA as an illustrative example. In our current work, we optimized the Cu-mediated synthesis of a novel monoacylglycerol lipase (MAGL) PET tracer ([18F]YH149), showing the versatility of droplet-based techniques for early stage tracer development. Across 5 days, we conducted a total of 117 experiments, studying 36 distinct conditions, while utilizing <15 mg of total organoboron precursor. Compared to the original report in which the radiochemical yield (RCY) was 4.4 ± 0.5% (n = 5), the optimized droplet condition provided a substantial improvement in RCY (52 ± 8%, n = 4) and showed excellent radiochemical purity (100%) and molar activity (77-854 GBq μmol-1), using a starting activity of 0.2-1.45 GBq. Furthermore, we showed for the first time a translation of the optimized microscale conditions to a vial-based method. With similar starting activity (0.2-1.44 GBq), the translated synthesis exhibited a comparable RCY of 50 ± 10% (n = 4) while maintaining excellent radiochemical purity (100%) and acceptable molar activity (20-46 GBq μmol-1). The successful translation to vial-based reactions ensures wider applicability of the optimized synthesis by leveraging widely available commercial vial-based synthesis modules.
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Affiliation(s)
- Yingqing Lu
- Crump Institute for Molecular Imaging, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
- Department of Molecular & Medical Pharmacology, UCLA, Los Angeles, CA, USA
- Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA, Los Angeles, CA, USA
| | - Yingfang He
- Center for Radiopharmaceutical Sciences, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Roger Schibli
- Center for Radiopharmaceutical Sciences, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Linjing Mu
- Center for Radiopharmaceutical Sciences, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - R Michael van Dam
- Crump Institute for Molecular Imaging, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
- Department of Molecular & Medical Pharmacology, UCLA, Los Angeles, CA, USA
- Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA, Los Angeles, CA, USA
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4
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Laferriere-Holloway TS, Rios A, van Dam RM. Detrimental impact of aqueous mobile phases on 18F-labelled radiopharmaceutical analysis via radio-TLC. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2023; 15:377-387. [PMID: 36542448 PMCID: PMC9891729 DOI: 10.1039/d2ay01206e] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The list of new positron-emission tomography (PET) tracers has rapidly grown in the past decade, following discoveries of new biological targets and therapeutic strategies, with several compounds garnering recent regulatory approval for clinical use. During the development of synthesis methods and production of new tracers for imaging, analytical methods for radio-high performance liquid chromatography (radio-HPLC) and radio-thin layer chromatography (radio-TLC) separations need to be developed to assess radiochemical compositions. Radio-TLC is often faster, simpler, and sometimes more accurate than radio-HPLC (as there is no underestimation of [18F]fluoride when analyzing 18F-labeled radiopharmaceuticals). Many protocols have been developed for separating 18F-radiopharmaceuticals on silica TLC plates, typically with [18F]fluoride retained at the origin and the radiopharmaceutical (and impurities) migrating along the plate. Interestingly, many reports describe the use of aqueous conditions to mobilize polar species, but it is known that aqueous conditions can modify silica and alter its chromatographic behavior. In this technical note, we explore the effects that aqueous conditions have on the analysis of 18F-radiopharmaceutical mixtures, revealing that with sufficient water, the radionuclide ([18F]fluoride) can migrate away from the origin and can be split into multiple bands. Furthermore, water can hinder the migration of the radiopharmaceutical. These effects can lead to overlapped bands or reversal of the normally expected order of bands, potentially leading to the misinterpretation of results if care is not taken to validate the TLC method carefully.
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Affiliation(s)
- Travis S Laferriere-Holloway
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
| | - Alejandra Rios
- Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
| | - R Michael van Dam
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
- Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
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5
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Soloviev D, Dzien P, Mackintosh A, Malviya G, Brown G, Lewis D. High molar activity [ 18F]tetrafluoroborate synthesis for sodium iodide symporter imaging by PET. EJNMMI Radiopharm Chem 2022; 7:32. [PMID: 36512196 PMCID: PMC9747990 DOI: 10.1186/s41181-022-00185-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 12/02/2022] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Sodium iodide symporter (NIS) imaging by positron emission tomography (PET) is gaining traction in nuclear medicine, with an increasing number of human studies being published using fluorine-18 radiolabelled tetrafluoroborate ([18F]TFB). Clinical success of any radiotracer relies heavily on its accessibility, which in turn depends on the availability of robust radiolabelling procedures providing a radiotracer in large quantities and of high radiopharmaceutical quality. RESULTS Here we publish an improved radiolabelling method and quality control procedures for high molar activity [18F]TFB. The use of ammonium hydroxide for [18F]fluoride elution, commercially available boron trifluoride-methanol complex dissolved in acetonitrile as precursor and removal of unreacted [18F]fluoride on Florisil solid-phase extraction cartridges resulted in the reliable production of [18F]TFB on SYNTHRA and TRACERLAB FXFN automated synthesizers with radiochemical yields in excess of 30%, radiochemical purities in excess of 98% and molar activities in the range of 34-217 GBq/µmol at the end of synthesis. PET scanning of a mouse lung tumour model carrying a NIS reporter gene rendered images of high quality and improved sensitivity. CONCLUSIONS A novel automated radiosynthesis procedure for [18F]tetrafluoroborate has been developed that provides the radiotracer with high molar activity, suitable for preclinical imaging of NIS reporter gene.
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Affiliation(s)
- Dmitry Soloviev
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
| | - Piotr Dzien
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Agata Mackintosh
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Gaurav Malviya
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Gavin Brown
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - David Lewis
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
- School of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G611QH, UK
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6
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Oxidation-Cyclisation of Biphenyl Thioethers to Dibenzothiophenium Salts for Ultrarapid 18F-Labelling of PET Tracers. Int J Mol Sci 2022; 23:ijms232415481. [PMID: 36555122 PMCID: PMC9779140 DOI: 10.3390/ijms232415481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
18F-labelled radiotracers are in high demand and play an important role for diagnostic imaging with positron emission tomography (PET). Challenges associated with the synthesis of the labelling precursors and the incorporation of [18F]fluoride with practical activity yields at batch scale are the main limitations for the development of new 18F-PET tracers. Herein, we report a high-yielding and robust synthetic method to access naked dibenzothiophenium salt precursors of complex PET tracers and their labelling with [18F]fluoride. C-S cross-coupling of biphenyl-2-thioacetate with aryl halides followed by sequential oxidation-cyclisation of the corresponding thioethers gives dibenzothiophenium salts in good to excellent yields. Labelling of neutral and electron-deficient substrates with [18F]fluoride is ultrarapid and occurs under mild conditions (1 min at 90 °C) with high activity yields. The method enables facile synthesis of complex and sensitive radiotracers, as exemplified by radiofluorination of three clinically relevant PET tracers [18F]UCB-J, [18F]AldoView and [18F]FNDP, and can accelerate the development and clinical translation of new 18F-radiopharmaceuticals.
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7
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Microliter-scale reaction arrays for economical high-throughput experimentation in radiochemistry. Sci Rep 2022; 12:10263. [PMID: 35715457 PMCID: PMC9205965 DOI: 10.1038/s41598-022-14022-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/31/2022] [Indexed: 01/14/2023] Open
Abstract
The increasing number of positron-emission tomography (PET) tracers being developed to aid drug development and create new diagnostics has led to an increased need for radiosynthesis development and optimization. Current radiosynthesis instruments are designed to produce large-scale clinical batches and are often limited to performing a single synthesis before they must be decontaminated by waiting for radionuclide decay, followed by thorough cleaning or disposal of synthesizer components. Though with some radiosynthesizers it is possible to perform a few sequential radiosyntheses in a day, none allow for parallel radiosyntheses. Throughput of one or a few experiments per day is not well suited for rapid optimization experiments. To combat these limitations, we leverage the advantages of droplet-radiochemistry to create a new platform for high-throughput experimentation in radiochemistry. This system contains an array of 4 heaters, each used to heat a set of 16 reactions on a small chip, enabling 64 parallel reactions for the rapid optimization of conditions in any stage of a multi-step radiosynthesis process. As examples, we study the syntheses of several 18F-labeled radiopharmaceuticals ([18F]Flumazenil, [18F]PBR06, [18F]Fallypride, and [18F]FEPPA), performing > 800 experiments to explore the influence of parameters including base type, base amount, precursor amount, solvent, reaction temperature, and reaction time. The experiments were carried out within only 15 experiment days, and the small volume (~ 10 μL compared to the ~ 1 mL scale of conventional instruments) consumed ~ 100 × less precursor per datapoint. This new method paves the way for more comprehensive optimization studies in radiochemistry and substantially shortening PET tracer development timelines.
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8
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Wang J, van Dam RM. Economical Production of Radiopharmaceuticals for Preclinical Imaging Using Microdroplet Radiochemistry. Methods Mol Biol 2022; 2393:813-828. [PMID: 34837213 DOI: 10.1007/978-1-0716-1803-5_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The short-lived radiolabeled "tracers" needed for performing whole body imaging in animals or patients with positron-emission tomography (PET) are generally produced via automated "radiosynthesizers". Most current radiosynthesizers are designed for routine production of relatively large clinical batches and are very wasteful when only a small batch of a tracer is needed, such as is the case for preclinical in vivo PET imaging studies. To overcome the prohibitively high cost of producing small batches of PET tracers, we developed a droplet microreactor system that performs radiochemistry at the 1-10μL scale instead of the milliliter scale of conventional technologies. The overall yield for the droplet-based production of many PET tracers is comparable to conventional approaches, but 10-100× less reagents are consumed, the synthesis can be completed in much less time (<30 min), and only a small laboratory footprint and minimal radiation shielding are needed. By combining these advantages, droplet microreactors enable the economical production of small batches PET tracers on demand. Here, we describe the fabrication method of the droplet microreactor and the droplet-based synthesis of an example radiotracer ([18F]fallypride).
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA
| | - R Michael van Dam
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA.
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA.
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9
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Kanagasundaram T, Laube M, Wodtke J, Kramer CS, Stadlbauer S, Pietzsch J, Kopka K. Radiolabeled Silicon-Rhodamines as Bimodal PET/SPECT-NIR Imaging Agents. Pharmaceuticals (Basel) 2021; 14:1155. [PMID: 34832938 PMCID: PMC8623702 DOI: 10.3390/ph14111155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 02/07/2023] Open
Abstract
Radiolabeled fluorescent dyes are decisive for bimodal imaging as well as highly in demand for nuclear- and optical imaging. Silicon-rhodamines (SiRs) show unique near-infrared (NIR) optical properties, large quantum yields and extinction coefficients as well as high photostability. Here, we describe the synthesis, characterization and radiolabeling of novel NIR absorbing and emitting fluorophores from the silicon-rhodamine family for use in optical imaging (OI) combined with positron emission tomography (PET) or single photon emission computed tomography (SPECT), respectively. The presented photostable SiRs were characterized using NMR-, UV-Vis-NIR-spectroscopy and mass spectrometry. Moreover, the radiolabeling conditions using fluorine-18 or iodine-123 were extensively explored. After optimization, the radiofluorinated NIR imaging agents were obtained with radiochemical conversions (RCC) up to 70% and isolated radiochemical yields (RCY) up to 54% at molar activities of g.t. 70 GBq/µmol. Radioiodination delivered RCCs over 92% and allowed to isolate the 123I-labeled product in RCY of 54% at a molar activity of g.t. 7.6 TBq/µmol. The radiofluorinated SiRs exhibit in vitro stabilities g.t. 70% after two hours in human serum. The first described radiolabeled SiRs are a promising step toward their further development as multimodal PET/SPECT-NIR imaging agents for planning and subsequent imaging-guided oncological surgery.
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Affiliation(s)
- Thines Kanagasundaram
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Bautzner Landstrasse 400, 01328 Dresden, Germany; (T.K.); (M.L.); (J.W.); (S.S.); (J.P.)
- Institute of Inorganic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
- Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 223, 69120 Heidelberg, Germany;
| | - Markus Laube
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Bautzner Landstrasse 400, 01328 Dresden, Germany; (T.K.); (M.L.); (J.W.); (S.S.); (J.P.)
| | - Johanna Wodtke
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Bautzner Landstrasse 400, 01328 Dresden, Germany; (T.K.); (M.L.); (J.W.); (S.S.); (J.P.)
| | - Carsten Sven Kramer
- Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 223, 69120 Heidelberg, Germany;
| | - Sven Stadlbauer
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Bautzner Landstrasse 400, 01328 Dresden, Germany; (T.K.); (M.L.); (J.W.); (S.S.); (J.P.)
| | - Jens Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Bautzner Landstrasse 400, 01328 Dresden, Germany; (T.K.); (M.L.); (J.W.); (S.S.); (J.P.)
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany
| | - Klaus Kopka
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Bautzner Landstrasse 400, 01328 Dresden, Germany; (T.K.); (M.L.); (J.W.); (S.S.); (J.P.)
- Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 223, 69120 Heidelberg, Germany;
- Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01062 Dresden, Germany
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10
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Abstract
18F-fluorination is an important and growing field in organic synthesis that has attracted many chemists in the recent past. Here we present our own, biased perspective with a focus on our own chemistry that evaluates recent advances in the field and provides our opinion on the challenges for the development of new chemistry, so that it may have an impact on imaging. We hope that the manuscript will provide a useful guide to chemists to develop reliable and robust reaction chemistry suitable for radiofluorination to have a real impact on human health.
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Affiliation(s)
- Riya Halder
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Tobias Ritter
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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11
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Gower-Fry L, Kronemann T, Dorian A, Pu Y, Jaworski C, Wängler C, Bartenstein P, Beyer L, Lindner S, Jurkschat K, Wängler B, Bailey JJ, Schirrmacher R. Recent Advances in the Clinical Translation of Silicon Fluoride Acceptor (SiFA) 18F-Radiopharmaceuticals. Pharmaceuticals (Basel) 2021; 14:ph14070701. [PMID: 34358127 PMCID: PMC8309031 DOI: 10.3390/ph14070701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/15/2021] [Accepted: 07/17/2021] [Indexed: 12/20/2022] Open
Abstract
The incorporation of silicon fluoride acceptor (SiFA) moieties into a variety of molecules, such as peptides, proteins and biologically relevant small molecules, has improved the generation of 18F-radiopharmaceuticals for medical imaging. The efficient isotopic exchange radiofluorination process, in combination with the enhanced [18F]SiFA in vivo stability, make it a suitable strategy for fluorine-18 incorporation. This review will highlight the clinical applicability of [18F]SiFA-labeled compounds and discuss the significant radiotracers currently in clinical use.
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Affiliation(s)
- Lexi Gower-Fry
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Travis Kronemann
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Andreas Dorian
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Yinglan Pu
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Carolin Jaworski
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany;
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377 Munich, Germany; (P.B.); (L.B.); (S.L.)
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377 Munich, Germany; (P.B.); (L.B.); (S.L.)
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Marchioninistraße 15, 81377 Munich, Germany; (P.B.); (L.B.); (S.L.)
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, 44227 Dortmund, Germany;
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany;
| | - Justin J. Bailey
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB T6G 1Z2, Canada; (L.G.-F.); (T.K.); (A.D.); (Y.P.); (C.J.); (J.J.B.)
- Correspondence:
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12
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Jeon MH, Kwon YD, Kim MP, Torres GB, Seo JK, Son J, Ryu YH, Hong SY, Chun JH. Late-Stage 18F/ 19F Isotopic Exchange for the Synthesis of 18F-Labeled Sulfamoyl Fluorides. Org Lett 2021; 23:2766-2771. [PMID: 33725454 DOI: 10.1021/acs.orglett.1c00671] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Synthesis of sulfamoyl [18F]fluorides has been a challenging topic owing to the inefficient nucleophilic radiofluorination of sulfamoyl derivatives. Herein, we report an 18F/19F isotopic exchange approach to synthesize various sulfamoyl [18F]fluorides, otherwise inaccessible via direct synthesis from amines, with high radiochemical yields up to 97% (30 examples). This late-stage labeling protocol offers an efficient route to yield functionalized molecules by diversifying the chemical library possessing sulfamoyl functionalities through nucleophilic 18F incorporation within nitrogen-containing sulfur(VI) frameworks.
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Affiliation(s)
- Min Ho Jeon
- Department of Chemistry and Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Young-Do Kwon
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Min Pyeong Kim
- Department of Chemistry and Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Gianluca Bartolini Torres
- Department of Chemistry and Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Jeong Kon Seo
- UNIST Central Research Facility, Ulsan 44919, Republic of Korea
| | - Jeongmin Son
- Department of Nuclear Medicine, Yonsei University Health System, Seoul 03722, Republic of Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.,Department of Nuclear Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
| | - Sung You Hong
- Department of Chemistry and Department of Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Joong-Hyun Chun
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
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13
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Zheng Q, Xu H, Wang H, Du WGH, Wang N, Xiong H, Gu Y, Noodleman L, Sharpless KB, Yang G, Wu P. Sulfur [ 18F]Fluoride Exchange Click Chemistry Enabled Ultrafast Late-Stage Radiosynthesis. J Am Chem Soc 2021; 143:3753-3763. [PMID: 33630577 DOI: 10.1021/jacs.0c09306] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The lack of efficient [18F]fluorination processes and target-specific organofluorine chemotypes remains the major challenge of fluorine-18 positron emission tomography (PET). We report here an ultrafast isotopic exchange method for the radiosynthesis of novel PET agent aryl [18F]fluorosulfate enabled by the emerging sulfur fluoride exchange (SuFEx) click chemistry. The method has been applied to the fully automated 18F-radiolabeling of 25 structurally and functionally diverse aryl fluorosulfates with excellent radiochemical yield (83-100%, median 98%) and high molar activity (280 GBq μmol-1) at room temperature in 30 s. The purification of radiotracers requires no time-consuming HPLC but rather a simple cartridge filtration. We further demonstrate the imaging application of a rationally designed poly(ADP-ribose) polymerase 1 (PARP1)-targeting aryl [18F]fluorosulfate by probing subcutaneous tumors in vivo.
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Affiliation(s)
- Qinheng Zheng
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 94037, United States
| | - Hongtao Xu
- Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai 201210, China
| | - Hua Wang
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 94037, United States.,Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Wen-Ge Han Du
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Nan Wang
- Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai 201210, China
| | - Huan Xiong
- Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai 201210, China
| | - Yuang Gu
- Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai 201210, China
| | - Louis Noodleman
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - K Barry Sharpless
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 94037, United States
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai 201210, China
| | - Peng Wu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, United States
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14
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Borràs J, Lecina J, Foster J, Kashani R, Melendez-Alafort L, Sosabowski J, Suades J. Bioconjugated technetium carbonyls by transmetalation reaction with zinc derivatives. Bioorg Med Chem Lett 2021; 37:127840. [PMID: 33556570 DOI: 10.1016/j.bmcl.2021.127840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/20/2021] [Accepted: 01/26/2021] [Indexed: 12/14/2022]
Abstract
The transmetalation reaction between zinc dithiocarbamates functionalized with organic groups and the cation fac-[99mTc(H2O)3(CO)3]+ has been studied as a new strategy to bind biomolecules to this radionuclide for preparing radiopharmaceuticals with high molar activity. All complexes were obtained in high yields by heating at moderate temperatures and without subsequent purification. The chemical identity was ascertained by HPLC comparison with the homologous rhenium complexes. Stability studies in cysteine solution and serum have shown a good stability of the coordination set fac-[99mTc(CO)3(SS)(P)]. Preliminary biological studies of the radiocomplex functionalized with D-(+)-glucosamine with carcinoma cells have been performed.
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Affiliation(s)
- Jordi Borràs
- Departament de Química, Edifici C, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain
| | - Joan Lecina
- Departament de Química, Edifici C, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain
| | - Julie Foster
- Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, United Kingdom
| | - Roxana Kashani
- Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, United Kingdom
| | | | - Jane Sosabowski
- Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, United Kingdom
| | - Joan Suades
- Departament de Química, Edifici C, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain.
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15
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Taddei C, Morse CL, Kim MJ, Liow JS, Montero Santamaria J, Zhang A, Manly LS, Zanotti-Fregonara P, Gladding RL, Zoghbi SS, Innis RB, Pike VW. Synthesis of [ 18F]PS13 and Evaluation as a PET Radioligand for Cyclooxygenase-1 in Monkey. ACS Chem Neurosci 2021; 12:517-530. [PMID: 33491441 PMCID: PMC9021884 DOI: 10.1021/acschemneuro.0c00737] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cyclooxygenase-1 (COX-1) and its isozyme COX-2 are key enzymes in the syntheses of prostanoids. Imaging of COX-1 and COX-2 selective radioligands with positron emission tomography (PET) may clarify how these enzymes are involved in inflammatory conditions and assist in the discovery of improved anti-inflammatory drugs. We have previously labeled the selective high-affinity COX-1 ligand, 1,5-bis(4-methoxyphenyl)-3-(2,2,2-trifluoroethoxy)-1H-1,2,4-triazole (PS13), with carbon-11 (t1/2 = 20.4 min). This radioligand ([11C]PS13) has been successful for PET imaging of COX-1 in monkey and human brain and in periphery. [11C]PS13 is being used in clinical investigations. Alternative labeling of PS13 with fluorine-18 (t1/2 = 109.8 min) is desirable to provide a longer-lived radioligand in high activity that might be readily distributed among imaging centers. However, labeling of PS13 in its 1,1,1-trifluoroethoxy group is a radiochemical challenge. Here we assess two labeling approaches based on nucleophilic addition of cyclotron-produced [18F]fluoride ion to gem-difluorovinyl precursors, either to label PS13 in one step or to produce [18F]2,2,2-trifluoroethyl p-toluenesulfonate for labeling a hydroxyl precursor. From the latter two-step approach, we obtained [18F]PS13 ready for intravenous injection in a decay-corrected radiochemical yield of 7.9% and with a molar activity of up to 7.9 GBq/μmol. PET imaging of monkey brain with [18F]PS13 shows that this radioligand can specifically image and quantify COX-1 without radiodefluorination but with some radioactivity uptake in skull, ascribed to red bone marrow. The development of a new procedure for labeling PS13 with fluorine-18 at a higher molar activity is, however, desirable to suppress occupancy of COX-1 by carrier at baseline.
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Affiliation(s)
- Carlotta Taddei
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Min-Jeong Kim
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Jose Montero Santamaria
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Andrea Zhang
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Lester S Manly
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Robert L Gladding
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Sami S Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, Maryland 20892-1003, United States
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16
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Lisova K, Wang J, Chao PH, van Dam RM. A simple and efficient automated microvolume radiosynthesis of [ 18F]Florbetaben. EJNMMI Radiopharm Chem 2020; 5:30. [PMID: 33275179 PMCID: PMC7718361 DOI: 10.1186/s41181-020-00113-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 11/20/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Current automated radiosynthesizers are generally optimized for producing large batches of PET tracers. Preclinical imaging studies, however, often require only a small portion of a regular batch, which cannot be economically produced on a conventional synthesizer. Alternative approaches are desired to produce small to moderate batches to reduce cost and the amount of reagents and radioisotope needed to produce PET tracers with high molar activity. In this work we describe the first reported microvolume method for production of [18F]Florbetaben for use in imaging of Alzheimer's disease. PROCEDURES The microscale synthesis of [18F]Florbetaben was adapted from conventional-scale synthesis methods. Aqueous [18F]fluoride was azeotropically dried with K2CO3/K222 (275/383 nmol) complex prior to radiofluorination of the Boc-protected precursor (80 nmol) in 10 μL DMSO at 130 °C for 5 min. The resulting intermediate was deprotected with HCl at 90 °C for 3 min and recovered from the chip in aqueous acetonitrile solution. The crude product was purified via analytical scale HPLC and the collected fraction reformulated via solid-phase extraction using a miniature C18 cartridge. RESULTS Starting with 270 ± 100 MBq (n = 3) of [18F]Fluoride, the method affords formulated product with 49 ± 3% (decay-corrected) yield,> 98% radiochemical purity and a molar activity of 338 ± 55 GBq/μmol. The miniature C18 cartridge enables efficient elution with only 150 μL of ethanol which is diluted to a final volume of 1.0 mL, thus providing a sufficient concentration for in vivo imaging. The whole procedure can be completed in 55 min. CONCLUSIONS This work describes an efficient and reliable procedure to produce [18F]Florbetaben in quantities sufficient for large-scale preclinical applications. This method provides very high yields and molar activities compared to reported literature methods. This method can be applied to higher starting activities with special consideration given to automation and radiolysis prevention.
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Affiliation(s)
- Ksenia Lisova
- Physics & Biology in Medicine Interdepartmental Graduate Program, University of California Los Angeles, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
| | - Jia Wang
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Philip H Chao
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA
| | - R Michael van Dam
- Physics & Biology in Medicine Interdepartmental Graduate Program, University of California Los Angeles, Los Angeles, CA, USA.
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, USA.
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17
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Affiliation(s)
- Alexandre M. Sorlin
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Fuad O. Usman
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Connor K. English
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Hien M. Nguyen
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
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18
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Tay NES, Chen W, Levens A, Pistritto VA, Huang Z, Wu Z, Li Z, Nicewicz DA. 19F- and 18F-Arene Deoxyfluorination via Organic Photoredox-Catalysed Polarity-Reversed Nucleophilic Aromatic Substitution. Nat Catal 2020; 3:734-742. [PMID: 33791591 PMCID: PMC8009013 DOI: 10.1038/s41929-020-0495-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 07/08/2020] [Indexed: 11/09/2022]
Abstract
Nucleophilic aromatic substitution (SNAr) is routinely used to install 19F- and 18F- in aromatic molecules, but is typically limited to electron-deficient arenes due to kinetic barriers associated with C-F bond formation. Here we demonstrate that a polarity-reversed photoredox-catalysed arene deoxyfluorination operating via cation radical-accelerated nucleophilic aromatic substitution (CRA-SNAr) enables the fluorination of electron-rich arenes with 19F- and 18F- under mild conditions, thus complementing the traditional arene polarity requirements necessary for SNAr-based fluorination. The utility of our radiofluorination strategy is highlighted by short reaction times, compatibility with multiple nucleofuges, and high radiofluorination yields, especially that of an important cancer positron emission tomography (PET) agent [18F]5-fluorouracil ([18F]FU). Taken together, our fluorination approach enables the development of fluorinated and radiofluorinated compounds that can be difficult to access by classical SNAr strategies, with the potential for use in the synthesis and discovery of PET radiopharmaceuticals.
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Affiliation(s)
- Nicholas E S Tay
- Department of Chemistry, University of North Carolina at Chapel Hill, Venable Laboratories, Chapel Hill, North Carolina, 27599-3290, USA
| | - Wei Chen
- Biomedical Research Imaging Center, Department of Radiology, and UNC Lineberger Comprehensive Cancer Center, University of North Carolina- Chapel Hill, Chapel Hill, NC 27514, USA
| | - Alison Levens
- Department of Chemistry, University of North Carolina at Chapel Hill, Venable Laboratories, Chapel Hill, North Carolina, 27599-3290, USA
| | - Vincent A Pistritto
- Department of Chemistry, University of North Carolina at Chapel Hill, Venable Laboratories, Chapel Hill, North Carolina, 27599-3290, USA
| | - Zeng Huang
- Biomedical Research Imaging Center, Department of Radiology, and UNC Lineberger Comprehensive Cancer Center, University of North Carolina- Chapel Hill, Chapel Hill, NC 27514, USA
| | - Zhanhong Wu
- Biomedical Research Imaging Center, Department of Radiology, and UNC Lineberger Comprehensive Cancer Center, University of North Carolina- Chapel Hill, Chapel Hill, NC 27514, USA
| | - Zibo Li
- Biomedical Research Imaging Center, Department of Radiology, and UNC Lineberger Comprehensive Cancer Center, University of North Carolina- Chapel Hill, Chapel Hill, NC 27514, USA
| | - David A Nicewicz
- Department of Chemistry, University of North Carolina at Chapel Hill, Venable Laboratories, Chapel Hill, North Carolina, 27599-3290, USA
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19
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Kwon YD, Jeon MH, Park NK, Seo JK, Son J, Ryu YH, Hong SY, Chun JH. Synthesis of 18F-Labeled Aryl Fluorosulfates via Nucleophilic Radiofluorination. Org Lett 2020; 22:5511-5516. [PMID: 32589035 DOI: 10.1021/acs.orglett.0c01868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sulfuryl fluoride gas is a key reagent for SO2F transfer. However, conventional SO2F transfer reactions have limited 18F-radiochemistry translation, due to the inaccessibility of gaseous [18F]SO2F2. Herein, we report the first SO2F2-free synthesis of aryl [18F]fluorosulfates from both phenolic and isolated aryl imidazylate precursors with cyclotron-produced 18F-. The radiochemical yields ranged from moderate to good with excellent functional group tolerance. The reliability of our approach was validated by the automated radiosynthesis of 4-acetamidophenyl [18F]fluorosulfate.
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Affiliation(s)
- Young-Do Kwon
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Min Ho Jeon
- Department of Chemistry, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Nam Kyu Park
- Department of Chemistry, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Jeong Kon Seo
- UNIST Central Research Facility, Ulsan 44919, Republic of Korea
| | - Jeongmin Son
- Department of Nuclear Medicine, Yonsei University Health System, Seoul 03722, Republic of Korea
| | - Young Hoon Ryu
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.,Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
| | - Sung You Hong
- Department of Chemistry, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Joong-Hyun Chun
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
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20
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Lau J, Rousseau E, Kwon D, Lin KS, Bénard F, Chen X. Insight into the Development of PET Radiopharmaceuticals for Oncology. Cancers (Basel) 2020; 12:E1312. [PMID: 32455729 PMCID: PMC7281377 DOI: 10.3390/cancers12051312] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 12/20/2022] Open
Abstract
While the development of positron emission tomography (PET) radiopharmaceuticals closely follows that of traditional drug development, there are several key considerations in the chemical and radiochemical synthesis, preclinical assessment, and clinical translation of PET radiotracers. As such, we outline the fundamentals of radiotracer design, with respect to the selection of an appropriate pharmacophore. These concepts will be reinforced by exemplary cases of PET radiotracer development, both with respect to their preclinical and clinical evaluation. We also provide a guideline for the proper selection of a radionuclide and the appropriate labeling strategy to access a tracer with optimal imaging qualities. Finally, we summarize the methodology of their evaluation in in vitro and animal models and the road to clinical translation. This review is intended to be a primer for newcomers to the field and give insight into the workflow of developing radiopharmaceuticals.
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Affiliation(s)
- Joseph Lau
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Etienne Rousseau
- Department of Nuclear Medicine and Radiobiology, University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada;
| | - Daniel Kwon
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (K.-S.L.); (F.B.)
| | - Kuo-Shyan Lin
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (K.-S.L.); (F.B.)
| | - François Bénard
- Department of Molecular Oncology, BC Cancer, Vancouver, BC V5Z 1L3, Canada; (D.K.); (K.-S.L.); (F.B.)
| | - Xiaoyuan Chen
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA;
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21
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Wang J, Holloway T, Lisova K, van Dam RM. Green and efficient synthesis of the radiopharmaceutical [ 18F]FDOPA using a microdroplet reactor. REACT CHEM ENG 2020; 5:320-329. [PMID: 34164154 PMCID: PMC8218909 DOI: 10.1039/c9re00354a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
From an efficiency standpoint, microdroplet reactors enable significant improvements in the preparation of radiopharmaceuticals due to the vastly reduced reaction volume. To demonstrate these advantages, we adapt the conventional (macroscale) synthesis of the clinically-important positron-emission tomography tracer [18F]FDOPA, following the nucleophilic diaryliodonium salt approach, to a newly-developed ultra-compact microdroplet reaction platform. In this first microfluidic implementation of [18F]FDOPA synthesis, optimized via a high-throughput multi-reaction platform, the radiochemical yield (non-decay-corrected) was found to be comparable to macroscale reports, but the synthesis consumed significantly less precursor and organic solvents, and the synthesis process was much faster. In this initial report, we demonstrate the production of [18F]FDOPA in 15 MBq [400 μCi] amounts, sufficient for imaging of multiple mice, at high molar activity.
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Affiliation(s)
- Jia Wang
- Department of Bioengineering, Henry Samueli School of Engineering
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
| | - Travis Holloway
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
| | - Ksenia Lisova
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine
- Physics in Biology and Medicine Interdepartmental Graduate Program, UCLA, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
| | - R Michael van Dam
- Department of Bioengineering, Henry Samueli School of Engineering
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine
- Physics in Biology and Medicine Interdepartmental Graduate Program, UCLA, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA, USA
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22
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Narayanam MK, Toutov AA, Murphy JM. Rapid One-Step 18F-Labeling of Peptides via Heteroaromatic Silicon-Fluoride Acceptors. Org Lett 2020; 22:804-808. [DOI: 10.1021/acs.orglett.9b04160] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Maruthi Kumar Narayanam
- Department of Molecular and Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095, United States
| | - Anton A. Toutov
- Fuzionaire Diagnostics, Inc., 177 East Colorado Boulevard, Pasadena, California 91105, United States
| | - Jennifer M. Murphy
- Department of Molecular and Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, California 90095, United States
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23
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Wang J, van Dam RM. High-Efficiency Production of Radiopharmaceuticals via Droplet Radiochemistry: A Review of Recent Progress. Mol Imaging 2020; 19:1536012120973099. [PMID: 33296272 PMCID: PMC7731702 DOI: 10.1177/1536012120973099] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/02/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022] Open
Abstract
New platforms are enabling radiochemistry to be carried out in tiny, microliter-scale volumes, and this capability has enormous benefits for the production of radiopharmaceuticals. These droplet-based technologies can achieve comparable or better yields compared to conventional methods, but with vastly reduced reagent consumption, shorter synthesis time, higher molar activity (even for low activity batches), faster purification, and ultra-compact system size. We review here the state of the art of this emerging direction, summarize the radiotracers and prosthetic groups that have been synthesized in droplet format, describe recent achievements in scaling up activity levels, and discuss advantages and limitations and the future outlook of these innovative devices.
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA, Los Angeles, CA, USA
| | - R. Michael van Dam
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA, Los Angeles, CA, USA
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24
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Wang J, Chao PH, Slavik R, van Dam RM. Multi-GBq production of the radiotracer [18F]fallypride in a droplet microreactor. RSC Adv 2020; 10:7828-7838. [PMID: 35492189 PMCID: PMC9049805 DOI: 10.1039/d0ra01212b] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/11/2020] [Indexed: 12/17/2022] Open
Abstract
Microfluidics offers numerous advantages for the synthesis of short-lived radiolabeled imaging tracers: performing 18F-radiosyntheses in microliter-scale droplets has exhibited high efficiency, speed, and molar activity as well as low reagent consumption. However, most reports have been at the preclinical scale. In this study we integrate a [18F]fluoride concentrator and a microdroplet synthesizer to explore the possibility of synthesizing patient doses and multi-patient batches of clinically-acceptable tracers. In the integrated system, [18F]fluoride (up to 41 GBq [1.1 Ci]) in [18O]H2O (1 mL) was first concentrated ∼80-fold and then efficiently transferred to the 8 μL reaction chip as a series of small (∼0.5 μL) droplets. Each droplet rapidly dried at the reaction site of the pre-heated chip, resulting in localized accumulation of large amounts of radioactivity in the form of dried [18F]TBAF complex. The PET tracer [18F]fallypride was synthesized from this concentrated activity in an overall synthesis time of ∼50 min (including radioisotope concentration and transfer, droplet radiosynthesis, purification, and formulation), in amounts up to 7.2 GBq [0.19 Ci], sufficient for multiple clinical PET scans. The resulting batches of [18F]fallypride passed all QC tests needed to ensure safety for clinical injection. This integrated technology enabled for the first time the impact of a wide range of activity levels on droplet radiosynthesis to be studied. Furthermore, this substantial increase in scale expands the applications of droplet radiosynthesis to the production of clinically-relevant amounts of radiopharmaceuticals, and potentially even centralized production of clinical tracers in radiopharmacies. The overall system could be applied to fundamental studies of droplet-based radiochemical reactions, or to the production of radiopharmaceuticals labeled with a variety of isotopes used for imaging and/or targeted radiotherapeutics. Using a micro-cartridge based radionuclide concentrator enables the production of multiple (10 s) of clinical doses of the PET tracer [18F]fallypride with a droplet micro-reactor platform (8 μL).![]()
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Affiliation(s)
- Jia Wang
- Department of Bioengineering
- Henry Samueli School of Engineering
- UCLA
- Los Angeles
- USA
| | - Philip H. Chao
- Department of Bioengineering
- Henry Samueli School of Engineering
- UCLA
- Los Angeles
- USA
| | - Roger Slavik
- Ahmanson Translational Imaging Division
- David Geffen School of Medicine
- University of California
- Los Angeles
- USA
| | - R. Michael van Dam
- Department of Bioengineering
- Henry Samueli School of Engineering
- UCLA
- Los Angeles
- USA
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Lisova K, Chen BY, Wang J, Fong KMM, Clark PM, van Dam RM. Rapid, efficient, and economical synthesis of PET tracers in a droplet microreactor: application to O-(2-[ 18F]fluoroethyl)-L-tyrosine ([ 18F]FET). EJNMMI Radiopharm Chem 2019; 5:1. [PMID: 31893318 PMCID: PMC6938530 DOI: 10.1186/s41181-019-0082-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/21/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Conventional scale production of small batches of PET tracers (e.g. for preclinical imaging) is an inefficient use of resources. Using O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET), we demonstrate that simple microvolume radiosynthesis techniques can improve the efficiency of production by consuming tiny amounts of precursor, and maintaining high molar activity of the tracers even with low starting activity. PROCEDURES The synthesis was carried out in microvolume droplets manipulated on a disposable patterned silicon "chip" affixed to a heater. A droplet of [18F]fluoride containing TBAHCO3 was first deposited onto a chip and dried at 100 °C. Subsequently, a droplet containing 60 nmol of precursor was added to the chip and the fluorination reaction was performed at 90 °C for 5 min. Removal of protecting groups was accomplished with a droplet of HCl heated at 90 °C for 3 min. Finally, the crude product was collected in a methanol-water mixture, purified via analytical-scale radio-HPLC and formulated in saline. As a demonstration, using [18F]FET produced on the chip, we prepared aliquots with different molar activities to explore the impact on preclinical PET imaging of tumor-bearing mice. RESULTS The microdroplet synthesis exhibited an overall decay-corrected radiochemical yield of 55 ± 7% (n = 4) after purification and formulation. When automated, the synthesis could be completed in 35 min. Starting with < 370 MBq of activity, ~ 150 MBq of [18F]FET could be produced, sufficient for multiple in vivo experiments, with high molar activities (48-119 GBq/μmol). The demonstration imaging study revealed the uptake of [18F]FET in subcutaneous tumors, but no significant differences in tumor uptake as a result of molar activity differences (ranging 0.37-48 GBq/μmol) were observed. CONCLUSIONS A microdroplet synthesis of [18F]FET was developed demonstrating low reagent consumption, high yield, and high molar activity. The approach can be expanded to tracers other than [18F]FET, and adapted to produce higher quantities of the tracer sufficient for clinical PET imaging.
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Affiliation(s)
- Ksenia Lisova
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Bao Ying Chen
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jia Wang
- Crump Institute for Molecular Imaging, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kelly Mun-Ming Fong
- Crump Institute for Molecular Imaging, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peter M Clark
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, USA
- Crump Institute for Molecular Imaging, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - R Michael van Dam
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, USA.
- Crump Institute for Molecular Imaging, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, USA.
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26
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Yang BY, Telu S, Haskali MB, Morse CL, Pike VW. A Gas Phase Route to [ 18F]fluoroform with Limited Molar Activity Dilution. Sci Rep 2019; 9:14835. [PMID: 31619702 PMCID: PMC6795885 DOI: 10.1038/s41598-019-50747-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/12/2019] [Indexed: 01/03/2023] Open
Abstract
Positron emission tomography (PET) is an important imaging modality for biomedical research and drug development. PET requires biochemically selective radiotracers to realize full potential. Fluorine-18 (t1/2 = 109.8 min) is a major radionuclide for labeling such radiotracers but is only readily available in high activities from cyclotrons as [18F]fluoride ion. [18F]fluoroform has emerged for labeling tracers in trifluoromethyl groups. Prior methods of [18F]fluoroform synthesis used difluoro precursors in solution and led to high dilution with carrier and low molar activity (Am). We explored a new approach for the synthesis of [18F]fluoroform based on the radiosynthesis of [18F]fluoromethane from [18F]fluoride ion and then cobaltIII fluoride mediated gas phase fluorination. We estimate that carrier dilution in this process is limited to about 3-fold and find that moderate to high Am values can be achieved. We show that [18F]fluoroform so produced is highly versatile for rapidly and efficiently labeling various chemotypes that carry trifluoromethyl groups, thereby expanding prospects for developing new PET radiotracers.
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Affiliation(s)
- Bo Yeun Yang
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, MD, 20892-1003, USA
| | - Sanjay Telu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, MD, 20892-1003, USA
| | - Mohammad B Haskali
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, MD, 20892-1003, USA
| | - Cheryl L Morse
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, MD, 20892-1003, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Building 10, Room B3 C346A, 10 Center Drive, Bethesda, MD, 20892-1003, USA.
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27
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Knapp KA, Nickels ML, Manning HC. The Current Role of Microfluidics in Radiofluorination Chemistry. Mol Imaging Biol 2019; 22:463-475. [DOI: 10.1007/s11307-019-01414-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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28
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Wang J, Chao PH, van Dam RM. Ultra-compact, automated microdroplet radiosynthesizer. LAB ON A CHIP 2019; 19:2415-2424. [PMID: 31187109 PMCID: PMC7416997 DOI: 10.1039/c9lc00438f] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Application of microfluidics offers numerous advantages in the field of radiochemistry and could enable dramatic reductions in the cost of producing radiotracers for positron emission tomography (PET). Droplet-based microfluidics, in particular, requires only microgram quantities of expensive precursors and reagents (compared to milligram used in conventional radiochemistry systems), and occupies a more compact footprint (potentially eliminating the need for specialized shielding facilities, i.e. hot cells). However, the reported platforms for droplet radiosynthesis have several drawbacks, including high cost/complexity of microfluidic reactors, requirement for manual intervention (e.g. for adding reagents), or difficulty in precise control of droplet processes. We describe here a platform based on a particularly simple chip, where reactions take place atop a hydrophobic substrate patterned with a circular hydrophilic liquid trap. The overall supporting hardware (heater, rotating carousel of reagent dispensers, etc.) is very simple and the whole system could be packaged into a very compact format (about the size of a coffee cup). We demonstrate the consistent synthesis of [18F]fallypride with high yield, and show that protocols optimized using a high-throughput optimization platform we have developed can be readily translated to this device with no changes or re-optimization. We are currently exploring the use of this platform for routine production of a variety of 18F-labeled tracers for preclinical imaging and for production of tracers in clinically-relevant amounts by integrating the system with an upstream radionuclide concentrator.
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA. and Department of Bioengineering, UCLA, Los Angeles, CA, USA
| | - Philip H Chao
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA. and Department of Bioengineering, UCLA, Los Angeles, CA, USA
| | - R Michael van Dam
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA. and Department of Bioengineering, UCLA, Los Angeles, CA, USA
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29
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Rios A, Wang J, Chao PH, van Dam RM. A novel multi-reaction microdroplet platform for rapid radiochemistry optimization. RSC Adv 2019; 9:20370-20374. [PMID: 35514735 PMCID: PMC9065505 DOI: 10.1039/c9ra03639c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/17/2019] [Indexed: 12/20/2022] Open
Abstract
During the development of novel tracers for positron emission tomography (PET), the optimization of the synthesis is hindered by practical limitations on the number of experiments that can be performed per day. Here we present a microliter droplet chip that contains multiple sites (4 or 16) to perform reactions simultaneously under the same or different conditions to accelerate radiosynthesis optimization. Multi-reaction microdroplet chip enables rapid radiotracer optimization for positron emission tomography.![]()
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Affiliation(s)
- Alejandra Rios
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA USA
| | - Jia Wang
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Department of Bioengineering, UCLA USA
| | - Philip H Chao
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Department of Bioengineering, UCLA USA
| | - R Michael van Dam
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA USA.,Department of Bioengineering, UCLA USA.,Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, UCLA USA
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30
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Kim HK, Javed MR, Chen S, Zettlitz KA, Collins J, Wu AM, Kim CJ“CJ, Michael van Dam R, Keng PY. On-demand radiosynthesis of N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB) on an electrowetting-on-dielectric microfluidic chip for 18F-labeling of protein. RSC Adv 2019; 9:32175-32183. [PMID: 35530758 PMCID: PMC9072849 DOI: 10.1039/c9ra06158d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/17/2019] [Indexed: 12/16/2022] Open
Abstract
An all-electronic, droplet-based batch microfluidic device, operated using the electrowetting on dielectric (EWOD) mechanism was developed for on-demand synthesis of N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB), the most commonly used 18F-prosthetic group for biomolecule labeling. In order to facilitate the development of peptides, and proteins as new diagnostic and therapeutic agents, we have diversified the compact EWOD microfluidic platform to perform the three-step radiosynthesis of [18F]SFB starting from the no carrier added [18F]fluoride ion. In this report, we established an optimal microliter droplet reaction condition to obtain reliable yields and synthesized [18F]SFB with sufficient radioactivity for subsequent conjugation to the anti-PSCA cys-diabody (A2cDb) and for small animal imaging. The three-step, one-pot radiosynthesis of [18F]SFB radiochemistry was adapted to a batch microfluidic platform with a reaction droplet sandwiched between two parallel plates of an EWOD chip, and optimized. Specifically, the ratio of precursor to base, droplet volume, reagent concentration, reaction time, and evaporation time were found be to be critical parameters. [18F]SFB was successfully synthesized on the EWOD chip in 39 ± 7% (n = 4) radiochemical yield in a total synthesis time of ∼120 min ([18F]fluoride activation, [18F]fluorination, hydrolysis, and coupling reaction, HPLC purification, drying and reformulation). The reformulation and stabilization step for [18F]SFB was important to obtain a high protein labeling efficiency of 33.1 ± 12.5% (n = 3). A small-animal immunoPET pilot study demonstrated that the [18F]SFB-PSCA diabody conjugate showed specific uptake in the PSCA-positive human prostate cancer xenograft. The successful development of a compact footprint of the EWOD radiosynthesizer has the potential to empower biologists to produce PET probes of interest themselves in a standard laboratory. An all-electronic, droplet-based batch microfluidic device, operated using the electrowetting on dielectric (EWOD) mechanism was developed for on-demand synthesis of acommonly used 18F-prosthetic group for biomolecule labeling.![]()
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Affiliation(s)
- Hee-Kwon Kim
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Muhammad Rashed Javed
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Supin Chen
- Department of Materials Science and Engineering
- National Tsing Hua University
- Hsinchu
- Taiwan
| | - Kirstin A. Zettlitz
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Jeffrey Collins
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Anna M. Wu
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Chang-Jin “C. J.” Kim
- Bioengineering Department
- University of California, Los Angeles
- Los Angeles
- USA
- Mechanical and Aerospace Engineering Department
| | - R. Michael van Dam
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Pei Yuin Keng
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
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31
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Chao PH, Lazari M, Hanet S, Narayanam MK, Murphy JM, van Dam RM. Automated concentration of [ 18F]fluoride into microliter volumes. Appl Radiat Isot 2018; 141:138-148. [PMID: 30243135 PMCID: PMC6502507 DOI: 10.1016/j.apradiso.2018.06.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/07/2018] [Accepted: 06/20/2018] [Indexed: 11/23/2022]
Abstract
Concentration of [18F]fluoride has been mentioned in literature, however, reports have lacked details about system designs, operation, and performance. Here, we describe in detail a compact, fast, fully-automated concentration system based on a micro-sized strong anion exchange cartridge. The concentration of radionuclides enables scaled-up microfluidic synthesis. Our system can also be used to provide highly concentrated [18F]fluoride with minimal water content. We demonstrate how the concentrator can produce varying concentrations of [18F]fluoride for the macroscale synthesis of N-boc-5-[18F]fluoroindole without an azeotropic drying process, while enabling high starting radioactivity. By appropriate choice of solid-phase resin, flow conditions, and eluent solution, we believe this approach can be extended beyond [18F]fluoride to other radionuclides.
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Affiliation(s)
- Philip H Chao
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Mark Lazari
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Sebastian Hanet
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Maruthi Kumar Narayanam
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Jennifer M Murphy
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - R Michael van Dam
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
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32
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Varlow C, Szames D, Dahl K, Bernard-Gauthier V, Vasdev N. Fluorine-18: an untapped resource in inorganic chemistry. Chem Commun (Camb) 2018; 54:11835-11842. [PMID: 30191929 PMCID: PMC6849477 DOI: 10.1039/c8cc04751k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Advances in the field of fluorine chemistry have been applied extensively to the syntheses of 18F-labelled organic compounds and radiopharmaceuticals. However, 18F has sparely been used as a tool to explore inorganic chemistry and can be viewed as a research area worthy of further development. This review highlights the application of 18F in development of inorganic fluorinating agents, mechanistic studies and imaging tools.
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Affiliation(s)
- Cassis Varlow
- Azrieli Centre for Neuro-Radiochemistry, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College St. Toronto, ON M5T-1R8, Canada.
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