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Gower-Fry L, Wängler C, Bartenstein P, Beyer L, Lindner S, Jurkschat K, Wängler B, Bailey JJ, Schirrmacher R. Silicon-Fluoride Acceptors (SiFA) for 18F-Radiolabeling: From Bench to Bedside. Methods Mol Biol 2024; 2729:29-43. [PMID: 38006489 DOI: 10.1007/978-1-0716-3499-8_3] [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: 11/27/2023]
Abstract
Fluorine-18 (18F) is undoubtedly one of the most frequently applied radionuclides for the development of new radiotracers for positron emission tomography (PET) in the context of clinical cancer, neurological, and metabolic imaging. Until recently, the available radiochemical methodologies to introduce 18F into organic molecules ranging from small- to medium- and large-sized compounds were limited to a few applicable protocols. With the advent of late-stage fluorination of small aromatic, nonactivated compounds and various noncanonical labeling strategies geared toward the labeling of peptides and proteins, the molecular toolbox for PET radiotracer development was substantially extended. Especially, the noncanonical labeling methodologies characterized by the formation of Si-18F, B-18F, and Al-18F bonds give access to kit-like 18F-labeling of complex and side-group unprotected compounds, some of them already in clinical use. This chapter will particularly focus on silicon-fluoride acceptor (SiFA) chemistry and cover the history of its conceptual design and its translation into the clinical practice.
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Affiliation(s)
- Lexi Gower-Fry
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada
| | - Carmen Wängler
- Biomedical Chemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Klaus Jurkschat
- Fakultät für Chemie und Chemische Biologie, Technische Universität Dortmund, Dortmund, Germany
| | - Björn Wängler
- Molecular Imaging and Radiochemistry, Department of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim of Heidelberg University, Mannheim, Germany
| | - Justin J Bailey
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada
| | - Ralf Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta, Edmonton, AB, Canada.
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Röther A, Farmer JC, Portwich FL, Görls H, Kretschmer R. Anion-Dependent Reactivity of Mono- and Dinuclear Boron Cations. Chemistry 2023; 29:e202302544. [PMID: 37641815 DOI: 10.1002/chem.202302544] [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: 08/04/2023] [Revised: 08/28/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
The dinuclear bis(N-heterocyclic carbene) borane adduct 2 rapidly reacts with tritylium salts at room temperature but the outcome is strongly impacted by the respective counter-ion. Using tritylium tetrakis(perfluoro-tert-butoxy)aluminate affords - depending on the solvent - either the bis(boronium) ion 4 or the hydride-bridged dication 5. In case of tritylium hexafluorophosphate, however, H/F exchange occurs between boron and phosphorus yielding the dinuclear BF3 adduct 3 along with phosphorus dihydride trifluoride. H/F exchange also takes place when using the mononuclear N-heterocyclic carbene BH3 adduct 6 and hence provides a facile route to PH2 F3 , which is usually synthesized in more complex reaction sequences regularly involving toxic hydrogen fluoride. DFT calculations shed light on the H/F exchange between the borenium ion and the [PF6 ]- counter-ion and the computed mechanism features only small barriers in line with the experimental observations.
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Affiliation(s)
- Alexander Röther
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - James C Farmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Flavio L Portwich
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry (IAAC), Friedrich Schiller University Jena, Humboldtstraße 8, 07743, Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
- Institute of Chemistry, Chemnitz University of Technology, Straße der Nationen 62, 09111, Chemnitz, Germany
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Radiochemistry with {Al18F}2+: Current status and optimization perspectives for efficient radiofluorination by complexation. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2023.215028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Holzleitner N, Günther T, Beck R, Lapa C, Wester HJ. Introduction of a SiFA Moiety into the D-Glutamate Chain of DOTA-PP-F11N Results in Radiohybrid-Based CCK-2R-Targeted Compounds with Improved Pharmacokinetics In Vivo. Pharmaceuticals (Basel) 2022; 15:ph15121467. [PMID: 36558917 PMCID: PMC9783573 DOI: 10.3390/ph15121467] [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: 11/07/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022] Open
Abstract
In order to enable 18F- and 177Lu-labelling within the same molecule, we introduced a silicon-based fluoride acceptor (SiFA) into the hexa-D-glutamate chain of DOTA-PP-F11N. In addition, minigastrin analogues with a prolonged as well as γ-linked D-glutamate chain were synthesised and evaluated. CCK-2R affinity (IC50, AR42J cells) and lipophilicity (logD7.4) were determined. Biodistribution studies at 24 h post-injection (p.i.) and µSPECT/CT imaging at 1, 4 and 24 h p.i. were carried out in AR42J tumour-bearing CB17-SCID mice. CCK-2R affinity of (R)-DOTAGA-rhCCK-1 to 18 was enhanced with increasing distance between the SiFA building block and the binding motif. Lipophilicity of [177Lu]Lu-(R)-DOTAGA-rhCCK-1 to 18 was higher compared to that of [177Lu]Lu-DOTA-PP-F11N and [177Lu]Lu-CP04. The respective α- and γ-linked rhCCK derivatives revealing the highest CCK-2R affinity were further evaluated in vivo. In comparison with [177Lu]Lu-DOTA-PP-F11N, [177Lu-]Lu-(R)-DOTAGA-rhCCK-9 and -16 exhibited three- to eight-fold increased activity levels in the tumour at 24 h p.i. However, activity levels in the kidneys were elevated as well. We could show that the introduction of a lipophilic SiFA moiety into the hydrophilic backbone of [177Lu]Lu-DOTA-PP-F11N led to a decelerated blood clearance and thus improved tumour retention. However, elevated kidney retention has to be addressed in future studies.
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Affiliation(s)
- Nadine Holzleitner
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
- Correspondence: (N.H.); (T.G.)
| | - Thomas Günther
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
- Correspondence: (N.H.); (T.G.)
| | - Roswitha Beck
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
| | - Constantin Lapa
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, 86156 Augsburg, Germany
| | - Hans-Jürgen Wester
- Pharmaceutical Radiochemistry, Technical University of Munich, 85748 Garching, Germany
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Kramer CS, Greiner L, Kopka K, Schäfer M. Fluorination of silyl prosthetic groups by fluorine mediated silyl ether linker cleavage: a concept study with conditions applicable in radiofluorination. EJNMMI Radiopharm Chem 2022; 7:15. [PMID: 35751707 PMCID: PMC9233720 DOI: 10.1186/s41181-022-00167-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Positron emission tomography (PET) is a powerful tool in medical imaging, especially in combination with the PET radionuclide fluorine-18 that possesses optimal characteristics. For labelling of biomolecules and low-molecular weight tracers, fluorine-18 can be covalently bound to silicon by either nucleophilic replacements of leaving groups (like ethers) or by isotope exchange of fluorine-19. While nucleophilic substitutions require additional purification steps for the removal of contaminants, isotope exchange with fluorine-18 results in low molar activity. Both challenges can be addressed with a detagging-fluorination of an immobilized silyl ether motif. RESULTS By overcoming the susceptibility towards hydrolysis, optimized detagging conditions (improved reaction time, fluorination reagent, linker, and resin) could afford the highly sterically hindered silyl fluoride motifs, that are commonly applied in radiochemistry in small and semipreparative scales. The described reaction conditions with fluorine-19 are transferrable to conditions with [18F]fluoride and silyl fluorides were obtained after approx. 10 min reaction time and in high-purity after mechanical filtration. CONCLUSIONS We present a proof-of-concept study for a detagging-fluorination of two silyl ethers that are bound to an optimized amino alcohol resin. We show with our model substrate that our solid-phase linker combination is capable of yielding the desired silicon fluoride in amounts sufficient for biological studies in animals or humans under standard fluorination conditions that may also be transferred to a radiolabelling setting. In conclusion, our presented approach could optimize the molar activity and simplify the preparation of radiofluorinated silyl fluorides.
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Affiliation(s)
- Carsten Sven Kramer
- Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 223, 69120, Heidelberg, Germany.
| | - Luca Greiner
- Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 223, 69120, Heidelberg, Germany
| | - Klaus Kopka
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR) e. v., Bautzner Landstrasse 400, 01328, Dresden, Germany.,Fakultät Chemie Und Lebensmittelchemie, Technische Universität Dresden, Mommsenstraße 4, 01062, Dresden, Germany
| | - Martin Schäfer
- Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 223, 69120, Heidelberg, Germany
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Petrov SA, Zyk NY, Machulkin AE, Beloglazkina EK, Majouga AG. PSMA-targeted low-molecular double conjugates for diagnostics and therapy. Eur J Med Chem 2021; 225:113752. [PMID: 34464875 DOI: 10.1016/j.ejmech.2021.113752] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/27/2021] [Accepted: 08/05/2021] [Indexed: 12/24/2022]
Abstract
This review presents data on dual conjugates of therapeutic and diagnostic action for targeted delivery to prostate cancer cells. The works of the last ten years on this topic were analyzed. The mail attention focuses on low-molecular-weight conjugates directed to the prostate-specific membrane antigen (PSMA); the comparison of high and low molecular weight PSMA-targeted conjugates was made. The considered conjugates were divided in the review into two main classes: diagnostic bimodal conjugates (which are containing two fragments for different types of diagnostics), theranostic conjugates (containing both therapeutic and diagnostic agents); also bimodal high molecular weight therapeutic conjugates containing two therapeutic agents are briefly discussed. The data of in vitro and in vivo studies for PSMA-targeted double conjugates available by the beginning of 2021 have been analyzed.
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Affiliation(s)
- Stanislav A Petrov
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - Nikolay Y Zyk
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | | | | | - Alexander G Majouga
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia; Laboratory of Biomedical Nanomaterials, National University of Science and Technology MISiS, Moscow, Russia; Mendeleev University of Chemical Technology of Russia, Moscow, Russia
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Luzi F, Gee AD, Bongarzone S. Silicon compounds in carbon-11 radiochemistry: present use and future perspectives. Org Biomol Chem 2021; 19:6916-6925. [PMID: 34319335 PMCID: PMC8372417 DOI: 10.1039/d1ob01202a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Positron emission tomography (PET) is a powerful functional imaging technique that requires the use of positron emitting nuclides. Carbon-11 (11C) radionuclide has several advantages related to the ubiquity of carbon atoms in biomolecules and the conservation of pharmacological properties of the molecule upon isotopic exchange of carbon-12 with carbon-11. However, due to the short half-life of 11C (20.4 minutes) and the low scale with which it is produced by the cyclotron (sub-nanomolar concentrations), quick, robust and chemospecific radiolabelling strategies are required to minimise activity loss during incorporation of the 11C nuclide into the final product. To address some of the constraints of working with 11C, the use of silicon-based chemistry for 11C-labelling was proposed as a rapid and effective route for radiopharmaceutical production due to the broad applicability and high efficiency showed in organic chemistry. In the past years several organic chemistry methodologies have been successfully applied to 11C-chemistry. In this short review, we examine silicon-based 11C-chemistry, with a particular emphasis on the radiotracers that have been successfully produced and potential improvements to further expand the applicability of silicon in radiochemistry. The use of silicon-based reagents and precursors for carbon-11 labelling has shown wide applicability and robustness with short reaction times using mild conditions. In this review, recent advances and future perspectives are examined.![]()
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Affiliation(s)
- Federico Luzi
- School of Biomedical Engineering and Imaging Sciences, 4th floor Lambeth Wing, St Thomas' Hospital, King's College London, London SE1 7EH, UK.
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Felber VB, Wester HJ. Small peptide-based GLP-1R ligands: an approach to reduce the kidney uptake of radiolabeled GLP-1R-targeting agents? EJNMMI Radiopharm Chem 2021; 6:29. [PMID: 34432147 PMCID: PMC8387526 DOI: 10.1186/s41181-021-00136-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/04/2021] [Indexed: 11/23/2022] Open
Abstract
Aim Elevated kidney uptake in insulinoma patients remains a major limitation of radiometallated exendin-derived ligands of the glucagon-like peptide 1 receptor (GLP-1R). Based on the previously published potent GLP-1R-activating undecapeptide 1, short-chained GLP-1R ligands were developed to investigate whether kidney uptake can be reduced by means of direct 18F-labeling (nuclide-based accelerated renal excretion) or the reduction of the overall ligand charge (ligand-based reduced kidney uptake). Materials & methods GLP-1R ligands were prepared according to optimized standard protocols via solid-phase peptide synthesis (SPPS) or, when not practicable, via fragment coupling in solution. Synthesis of (2‘-Et, 4‘-OMe)4, 4’-L-biphenylalanine ((2′-Et, 4′-OMe)BIP), required for the preparation of 1, was accomplished by Suzuki-Miyaura cross-coupling. In vitro experiments were performed using stably transfected GLP-1R+ HEK293-hGLP-1R cells. Results In contrast to the three reference ligands glucagon-like peptide 1 (GLP-1, IC50 = 23.2 ± 12.2 nM), [Nle14, Tyr(3-I)40]exendin-4 (IC50 = 7.63 ± 2.78 nM) and [Nle14, Tyr40]exendin-4 (IC50 = 9.87 ± 1.82 nM), the investigated GLP-1R-targeting small peptides (9–15 amino acids), including lead peptide 1, exhibited only medium to low affinities (IC50 > 189 nM). Only SiFA-tagged undecapeptide 5 (IC50 = 189 ± 35 nM) revealed a higher affinity than 1 (IC50 = 669 ± 242 nM). Conclusion The investigated small peptides, including lead peptide 1, could not compete with favorable in vitro characteristics of glucagon-like peptide 1 (GLP-1), [Nle14, Tyr(3-I)40]exendin-4 and [Nle14, Tyr40]exendin-4. The auspicious EC50 values of 1 provided by the literature could not be transferred to competitive binding experiments. Therefore, the use of 1 as a basic scaffold for the design of further GLP-1R-targeting radioligands cannot be recommended. Further investigations might include the scaffold of 5, although substantial optimizations concerning affinity and lipophilicity would be required. In sum, GLP-1R-targeting radioligands with reduced kidney uptake could not be obtained in this work, which emphasizes the need for further ligands addressing this particular issue. Supplementary Information The online version contains supplementary material available at 10.1186/s41181-021-00136-x.
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Affiliation(s)
- Veronika Barbara Felber
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany.
| | - Hans-Jürgen Wester
- Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Walther-Meißner-Str. 3, 85748, Garching, Germany
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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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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: 75] [Impact Index Per Article: 25.0] [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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Automated synthesis of [ 18F]Ga-rhPSMA-7/ -7.3: results, quality control and experience from more than 200 routine productions. EJNMMI Radiopharm Chem 2021; 6:4. [PMID: 33484364 PMCID: PMC7826325 DOI: 10.1186/s41181-021-00120-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/11/2021] [Indexed: 12/15/2022] Open
Abstract
Introduction The radiohybrid (rh) prostate-specific membrane antigen (PSMA)-targeted ligand [18F]Ga-rhPSMA-7 has previously been clinically assessed and demonstrated promising results for PET-imaging of prostate cancer. The ligand is present as a mixture of four stereoisomers ([18F]Ga-rhPSMA-7.1, − 7.2, − 7.3 and − 7.4) and after a preclinical isomer selection process, [18F]Ga-rhPSMA-7.3 has entered formal clinical trials. Here we report on the establishment of a fully automated production process for large-scale production of [18F]Ga-rhPSMA-7/ -7.3 under GMP conditions (EudraLex). Methods [18F]Fluoride in highly enriched [18O]H2O was retained on a strong anion exchange cartridge, rinsed with anhydrous acetonitrile and subsequently eluted with a solution of [K+ ⊂ 2.2.2]OH− in anhydrous acetonitrile into a reactor containing Ga-rhPSMA ligand and oxalic acid in DMSO. 18F-for-19F isotopic exchange at the Silicon-Fluoride Acceptor (SiFA) was performed at room temperature, followed by dilution with buffer and cartridge-based purification. Optimum process parameters were determined on the laboratory scale and thereafter implemented into an automated synthesis. Data for radiochemical yield (RCY), purity and quality control were analyzed for 243 clinical productions (160 for [18F]Ga-rhPSMA-7; 83 for [18F]Ga-rhPSMA-7.3). Results The automated production of [18F]Ga-rhPSMA-7 and the single isomer [18F]Ga-rhPSMA-7.3 is completed in approx. 16 min with an average RCY of 49.2 ± 8.6% and an excellent reliability of 98.8%. Based on the different starting activities (range: 31–130 GBq, 89 ± 14 GBq) an average molar activity of 291 ± 62 GBq/μmol (range: 50–450 GBq/μmol) was reached for labeling of 150 nmol (231 μg) precursor. Radiochemical purity, as measured by radio-high performance liquid chromatography and radio-thin layer chromatography, was 99.9 ± 0.2% and 97.8 ± 1.0%, respectively. Conclusion This investigation demonstrates that 18F-for-19F isotopic exchange is well suited for the fast, efficient and reliable automated routine production of 18F-labeled PSMA-targeted ligands. Due to its simplicity, speed and robustness the development of further SiFA-based radiopharmaceuticals is highly promising and can be of far-reaching importance for future theranostic concepts. Supplementary Information The online version contains supplementary material available at 10.1186/s41181-021-00120-5.
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Methods to radiolabel somatostatin analogs with [18F]fluoride: current status, challenges, and progress in clinical applications. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Lindner S, Wängler C, Bailey JJ, Jurkschat K, Bartenstein P, Wängler B, Schirrmacher R. Radiosynthesis of [18F]SiFAlin-TATE for clinical neuroendocrine tumor positron emission tomography. Nat Protoc 2020; 15:3827-3843. [DOI: 10.1038/s41596-020-00407-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 09/08/2020] [Indexed: 12/13/2022]
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14
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Otaru S, Niemikoski H, Sarparanta M, Airaksinen AJ. Metabolism of a Bioorthogonal PET Tracer Candidate [ 19F/ 18F]SiFA-Tetrazine in Mouse Liver Microsomes: Biotransformation Pathways and Defluorination Investigated by UHPLC-HRMS. Mol Pharm 2020; 17:3106-3115. [PMID: 32539414 PMCID: PMC7497667 DOI: 10.1021/acs.molpharmaceut.0c00523] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Organofluorosilicon based 18F-radiolabeling is an efficient
method for incorporating fluorine-18 into 18F-radiopharmaceuticals
for positron emission tomography (PET) by 19F/18F isotopic exchange (IE). The first PET radiopharmaceutical, 18F-SiFAlin-TATE, radiolabeled with a silicon-based
[18F]fluoride acceptor (SiFA), namely, a para-substituted
di-tert-butyl[18F]fluorosilylbenzene,
has entered clinical trials, and is paving the way for other potential
[18F]SiFA-labeled radiopharmaceuticals for diagnostic use.
In this study, we report the in vitro metabolism
of an oxime-linked SiFA tetrazine (SiFA–Tz), a new PET-radiotracer
candidate, recently evaluated for pretargeted PET imaging and macromolecule
labeling. Metabolism of SiFA–Tz was studied in mouse liver
microsomes (MLM) for elucidating its major biotransformation pathways.
Nontargeted screening by ultrahigh performance liquid chromatography
high-resolution mass spectrometry (UHPLC-HRMS) was utilized for detection
of unknown metabolites. The oxime bond between the SiFA and Tz groups
forms two geometric (E/Z) isomers,
which underwent the same biotransformations, but unexpectedly with
different kinetics. In total, nine proposed metabolites of SiFA–Tz
from phase I and II reactions were detected, five of which were defluorinated
in MLMs, elucidating the metabolic pathway leading to previously reported
defluorination of [18F]SiFA–Tz in vivo. Based on the HRMS studies a biotransformation pathway is proposed:
hydroxylation (+O) to tert-butyl group adjacent to
the silicon, followed by oxidative defluorination (+OH/-F) cleaving
the fluorine off the silicon. Interestingly, eight proposed metabolites
of a reduced dihydrotetrazine analogue, SiFA–H2Tz,
from phase I and II reactions were additionally detected. To the best
of our knowledge, this is the first reported comprehensive investigation
of enzyme mediated metabolic pathway of tetrazines and para-substituted
di-tert-butylfluorosilylbenzene fluoride acceptors,
providing novel structural information on the biotransformation and
fragmentation patterns of radiotracers bearing these structural motifs.
By investigating the metabolism preceding defluorination, structurally
optimized new SiFA compounds can be designed for expanding the portfolio
of efficient 19F/18F isotopic exchange labeling
probes for PET imaging.
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Affiliation(s)
- Sofia Otaru
- Radiochemistry, Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Hanna Niemikoski
- Finnish Institute for Verification of the Chemical Weapons Convention (VERIFIN), Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Mirkka Sarparanta
- Radiochemistry, Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Anu J Airaksinen
- Radiochemistry, Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland.,Turku PET Centre, Department of Chemistry, University of Turku, 20500 Turku, Finland
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15
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Kee C, Tack O, Guibbal F, Wilson TC, Isenegger PG, Imiołek M, Verhoog S, Tilby M, Boscutti G, Ashworth S, Chupin J, Kashani R, Poh AWJ, Sosabowski JK, Macholl S, Plisson C, Cornelissen B, Willis MC, Passchier J, Davis BG, Gouverneur V. 18F-Trifluoromethanesulfinate Enables Direct C-H 18F-Trifluoromethylation of Native Aromatic Residues in Peptides. J Am Chem Soc 2020; 142:1180-1185. [PMID: 31913613 PMCID: PMC6978814 DOI: 10.1021/jacs.9b11709] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Indexed: 12/27/2022]
Abstract
18F labeling strategies for unmodified peptides with [18F]fluoride require 18F-labeled prosthetics for bioconjugation more often with cysteine thiols or lysine amines. Here we explore selective radical chemistry to target aromatic residues applying C-H 18F-trifluoromethylation. We report a one-step route to [18F]CF3SO2NH4 from [18F]fluoride and its application to direct [18F]CF3 incorporation at tryptophan or tyrosine residues using unmodified peptides as complex as recombinant human insulin. The fully automated radiosynthesis of octreotide[Trp(2-CF218F)] enables in vivo positron emission tomography imaging.
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Affiliation(s)
- Choon
Wee Kee
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Osman Tack
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Florian Guibbal
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
- Radiobiology
Research Institute, Department of Oncology, University of Oxford, Headington, Oxford OX3 7LJ, U.K.
| | - Thomas C. Wilson
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Patrick G. Isenegger
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Mateusz Imiołek
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Stefan Verhoog
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Michael Tilby
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | | | | | - Juliette Chupin
- Invicro
Ltd, Du Cane Road, London W12 0NN, U.K.
- Centre
for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, U.K.
| | - Roxana Kashani
- Centre
for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, U.K.
| | - Adeline W. J. Poh
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Jane K. Sosabowski
- Centre
for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, U.K.
| | - Sven Macholl
- Invicro
Ltd, Du Cane Road, London W12 0NN, U.K.
- Centre
for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London EC1M 6BQ, U.K.
| | | | - Bart Cornelissen
- Radiobiology
Research Institute, Department of Oncology, University of Oxford, Headington, Oxford OX3 7LJ, U.K.
| | - Michael C. Willis
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | | | - Benjamin G. Davis
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Véronique Gouverneur
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
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16
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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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17
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Fersing C, Bouhlel A, Cantelli C, Garrigue P, Lisowski V, Guillet B. A Comprehensive Review of Non-Covalent Radiofluorination Approaches Using Aluminum [ 18F]fluoride: Will [ 18F]AlF Replace 68Ga for Metal Chelate Labeling? Molecules 2019; 24:E2866. [PMID: 31394799 PMCID: PMC6719958 DOI: 10.3390/molecules24162866] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/31/2019] [Accepted: 08/06/2019] [Indexed: 12/20/2022] Open
Abstract
Due to its ideal physical properties, fluorine-18 turns out to be a key radionuclide for positron emission tomography (PET) imaging, for both preclinical and clinical applications. However, usual biomolecules radiofluorination procedures require the formation of covalent bonds with fluorinated prosthetic groups. This drawback makes radiofluorination impractical for routine radiolabeling, gallium-68 appearing to be much more convenient for the labeling of chelator-bearing PET probes. In response to this limitation, a recent expansion of the 18F chemical toolbox gave aluminum [18F]fluoride chemistry a real prominence since the late 2000s. This approach is based on the formation of an [18F][AlF]2+ cation, complexed with a 9-membered cyclic chelator such as NOTA, NODA or their analogs. Allowing a one-step radiofluorination in an aqueous medium, this technique combines fluorine-18 and non-covalent radiolabeling with the advantage of being very easy to implement. Since its first reports, [18F]AlF radiolabeling approach has been applied to a wide variety of potential PET imaging vectors, whether of peptidic, proteic, or small molecule structure. Most of these [18F]AlF-labeled tracers showed promising preclinical results and have reached the clinical evaluation stage for some of them. The aim of this report is to provide a comprehensive overview of [18F]AlF labeling applications through a description of the various [18F]AlF-labeled conjugates, from their radiosynthesis to their evaluation as PET imaging agents.
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Affiliation(s)
- Cyril Fersing
- Institut de Recherche en Cancérologie de Montpellier (IRCM), University of Montpellier, INSERM U1194, Montpellier Cancer Institute (ICM), 34298 Montpellier, France.
- Nuclear Medicine Department, Montpellier Cancer Institute (ICM), University of Montpellier, 208 Avenue des Apothicaires, 34298 Montpellier CEDEX 5, France.
| | - Ahlem Bouhlel
- CERIMED, Aix-Marseille University, 13005 Marseille, France
- Centre de recherche en CardioVasculaire et Nutrition (C2VN), Aix-Marseille University, INSERM 1263, INRA 1260, 13385 Marseille, France
| | - Christophe Cantelli
- Institut de Recherche en Cancérologie de Montpellier (IRCM), University of Montpellier, INSERM U1194, Montpellier Cancer Institute (ICM), 34298 Montpellier, France
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS, Université de Montpellier, ENSCM, UFR des Sciences Pharmaceutiques et Biologiques, 34093 Montpellier CEDEX, France
| | - Philippe Garrigue
- CERIMED, Aix-Marseille University, 13005 Marseille, France
- Centre de recherche en CardioVasculaire et Nutrition (C2VN), Aix-Marseille University, INSERM 1263, INRA 1260, 13385 Marseille, France
- Department of Nuclear Medicine, Aix-Marseille University, Assistance Publique-Hôpitaux de Marseille (AP-HM), 13385 Marseille, France
| | - Vincent Lisowski
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS, Université de Montpellier, ENSCM, UFR des Sciences Pharmaceutiques et Biologiques, 34093 Montpellier CEDEX, France
| | - Benjamin Guillet
- CERIMED, Aix-Marseille University, 13005 Marseille, France
- Centre de recherche en CardioVasculaire et Nutrition (C2VN), Aix-Marseille University, INSERM 1263, INRA 1260, 13385 Marseille, France
- Department of Nuclear Medicine, Aix-Marseille University, Assistance Publique-Hôpitaux de Marseille (AP-HM), 13385 Marseille, France
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18
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Karaman DŞ, Sarparanta MP, Rosenholm JM, Airaksinen AJ. Multimodality Imaging of Silica and Silicon Materials In Vivo. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1703651. [PMID: 29388264 DOI: 10.1002/adma.201703651] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/15/2017] [Indexed: 05/29/2023]
Abstract
Recent progress in the development of silica- and silicon-based multimodality imaging nanoprobes has advanced their use in image-guided drug delivery, and the development of novel systems for nanotheranostic and diagnostic applications. As biocompatible and flexibly tunable materials, silica and silicon provide excellent platforms with high clinical potential in nanotheranostic and diagnostic probes with well-defined morphology and surface chemistry, yielding multifunctional properties. In vivo imaging is of great value in the exploration of methods for improving site-specific nanotherapeutic delivery by silica- and silicon-based drug-delivery systems. Multimodality approaches are essential for understanding the biological interactions of nanotherapeutics in the physiological environment in vivo. The aim here is to describe recent advances in the development of in vivo imaging tools based on nanostructured silica and silicon, and their applications in single and multimodality imaging.
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Affiliation(s)
- Didem Şen Karaman
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, BioCity, Tykistökatu 6A, FI, 20520, Turku, Finland
| | - Mirkka P Sarparanta
- Department of Chemistry-Radiochemistry, Faculty of Science, University of Helsinki, POB 55, FI-00014, University of Helsinki, Finland
| | - Jessica M Rosenholm
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, BioCity, Tykistökatu 6A, FI, 20520, Turku, Finland
| | - Anu J Airaksinen
- Department of Chemistry-Radiochemistry, Faculty of Science, University of Helsinki, POB 55, FI-00014, University of Helsinki, Finland
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19
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Scroggie KR, Alcock LJ, Matos MJ, Bernardes GJL, Perkins MV, Chalker JM. A silicon‐labelled amino acid suitable for late‐stage fluorination and unexpected oxidative cleavage reactions in the preparation of a key intermediate in the Strecker synthesis. Pept Sci (Hoboken) 2018. [DOI: 10.1002/pep2.24069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Kymberley R. Scroggie
- Flinders University, College of Science and EngineeringSouth Australia5042 Australia
| | - Lisa J. Alcock
- Flinders University, College of Science and EngineeringSouth Australia5042 Australia
| | - Maria J. Matos
- Department of ChemistryUniversity of CambridgeCambridgeCB2 1EW United Kingdom
| | - Gonçalo J. L. Bernardes
- Department of ChemistryUniversity of CambridgeCambridgeCB2 1EW United Kingdom
- Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas MonizInstituto de Medicina MolecularLisboa1649‐028 Portugal
| | - Michael V. Perkins
- Flinders University, College of Science and EngineeringSouth Australia5042 Australia
| | - Justin M. Chalker
- Flinders University, College of Science and EngineeringSouth Australia5042 Australia
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20
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Kumar K, Ghosh A. 18F-AlF Labeled Peptide and Protein Conjugates as Positron Emission Tomography Imaging Pharmaceuticals. Bioconjug Chem 2018; 29:953-975. [PMID: 29463084 DOI: 10.1021/acs.bioconjchem.7b00817] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The clinical applications of positron emission tomography (PET) imaging pharmaceuticals have increased tremendously over the past several years since the approval of 18fluorine-fluorodeoxyglucose (18F-FDG) by the Food and Drug Administration (FDA). Numerous 18F-labeled target-specific potential imaging pharmaceuticals, based on small and large molecules, have been evaluated in preclinical and clinical settings. 18F-labeling of organic moieties involves the introduction of the radioisotope by C-18F bond formation via a nucleophilic or an electrophilic substitution reaction. However, biomolecules, such as peptides, proteins, and oligonucleotides, cannot be radiolabeled via a C-18F bond formation as these reactions involve harsh conditions, including organic solvents, high temperature, and nonphysiological conditions. Several approaches, including 18F-labeled prosthetic groups, silicon, boron, and aluminum fluoride acceptor chemistry, and click chemistry have been developed, in the past, for 18F labeling of biomolecules. Linear and macrocyclic polyaminocarboxylates and their analogs and derivatives form thermodynamically stable and kinetically inert aluminum chelates. Hence, macrocyclic polyaminocarboxylates have been used for conjugation with biomolecules, such as folate, peptides, affibodies, and protein fragments, followed by 18F-AlF chelation, and evaluation of their targeting abilities in preclinical and clinical environments. The goal of this report is to provide an overview of the 18F radiochemistry and 18F-labeling methodologies for small molecules and target-specific biomolecules, a comprehensive review of coordination chemistry of Al3+, 18F-AlF labeling of peptide and protein conjugates, and evaluation of 18F-labeled biomolecule conjugates as potential imaging pharmaceuticals.
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Affiliation(s)
- Krishan Kumar
- Laboratory for Translational Research in Imaging Pharmaceuticals, The Wright Center of Innovation in Biomedical Imaging, Department of Radiology , The Ohio State University , Columbus , Ohio 43212 , United States
| | - Arijit Ghosh
- Laboratory for Translational Research in Imaging Pharmaceuticals, The Wright Center of Innovation in Biomedical Imaging, Department of Radiology , The Ohio State University , Columbus , Ohio 43212 , United States
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21
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Kommidi H, Tosi U, Maachani UB, Guo H, Marnell CS, Law B, Souweidane MM, Ting R. 18F-Radiolabeled Panobinostat Allows for Positron Emission Tomography Guided Delivery of a Histone Deacetylase Inhibitor. ACS Med Chem Lett 2018; 9:114-119. [PMID: 29456798 DOI: 10.1021/acsmedchemlett.7b00471] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/08/2018] [Indexed: 01/02/2023] Open
Abstract
Histone deacetylase (HDAC) inhibition is becoming an increasingly popular approach to treat cancer, as HDAC overexpression is common in many malignancies. The blood-brain barrier (BBB) prevents systemically delivered drugs from reaching brain at effective concentration, making small-molecule-HDAC inhibition in brain tumors particularly challenging. To circumvent the BBB, novel routes for administering therapeutics are being considered in the clinic, and a need exists for drugs whose deliveries can be directly imaged, so that effective delivery across the BBB can be monitored. We report chemistry for radiolabeling the HDAC inhibitor, panobinostat, with fluoride-18 (compound-1). Like panobinostat, compound 1 retains nanomolar efficacy in diffuse intrinsic pontine glioma (DIPG IV and XIII) cells (IC50 = 122 and 108 nM, respectively), with lesser activity against U87 glioma. With a favorable therapeutic ratio, 1 is highly selective to glioma and demonstrates considerably less toxicity toward healthy astrocyte controls (IC50 = 5265 nM). Compound 1 is stable in aqueous solution at physiological pH (>7 days, fetal bovine serum), and its delivery can be imaged by positron emission tomography (PET). Compound 1 is synthesized in two steps, and employs rapid, late-stage aqueous isotopic exchange 18F-radiochemistry. PET is used to image the in vivo delivery of [18F]-1 to the murine central nervous system via convection enhanced delivery.
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Affiliation(s)
- Harikrishna Kommidi
- Department
of Radiology, Molecular Imaging Innovations Institute, Weill Cornell Medicine, New York, New York 10065, United States
| | - Umberto Tosi
- Department
of Neurological Surgery, Weill Cornell Medicine, New York, New York 10065, United States
| | - Uday B. Maachani
- Department
of Neurological Surgery, Weill Cornell Medicine, New York, New York 10065, United States
| | - Hua Guo
- Department
of Radiology, Molecular Imaging Innovations Institute, Weill Cornell Medicine, New York, New York 10065, United States
| | - Christopher S. Marnell
- Department
of Neurological Surgery, Weill Cornell Medicine, New York, New York 10065, United States
| | - Benedict Law
- Department
of Radiology, Molecular Imaging Innovations Institute, Weill Cornell Medicine, New York, New York 10065, United States
| | - Mark M. Souweidane
- Department
of Neurological Surgery, Weill Cornell Medicine, New York, New York 10065, United States
| | - Richard Ting
- Department
of Radiology, Molecular Imaging Innovations Institute, Weill Cornell Medicine, New York, New York 10065, United States
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22
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Verhoog S, Kee CW, Wang Y, Khotavivattana T, Wilson TC, Kersemans V, Smart S, Tredwell M, Davis BG, Gouverneur V. 18F-Trifluoromethylation of Unmodified Peptides with 5- 18F-(Trifluoromethyl)dibenzothiophenium Trifluoromethanesulfonate. J Am Chem Soc 2018; 140:1572-1575. [PMID: 29301394 DOI: 10.1021/jacs.7b10227] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The 18F-labeling of 5-(trifluoromethyl)-dibenzothiophenium trifluoromethanesulfonate, commonly referred to as the Umemoto reagent, has been accomplished applying a halogen exchange 18F-fluorination with 18F-fluoride, followed by oxidative cyclization with Oxone and trifluoromethanesulfonic anhydride. This new 18F-reagent allows for the direct chemoselective 18F-labeling of unmodified peptides at the thiol cysteine residue.
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Affiliation(s)
- Stefan Verhoog
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Choon Wee Kee
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Yanlan Wang
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Tanatorn Khotavivattana
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Thomas C Wilson
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Veerle Kersemans
- Oxford Institute for Radiation Oncology, University of Oxford , Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Sean Smart
- Oxford Institute for Radiation Oncology, University of Oxford , Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Matthew Tredwell
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Benjamin G Davis
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Véronique Gouverneur
- Chemistry Research Laboratory, University of Oxford , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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23
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Rugeri B, Audi H, Jewula P, Koudih R, Malacea-Kabbara R, Vimont D, Schulz J, Fernandez P, Jugé S. Designing Silylatedl-Amino Acids using a Wittig Strategy: Synthesis of Peptide Derivatives and18F-Labelling. European J Org Chem 2017. [DOI: 10.1002/ejoc.201701170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Baptiste Rugeri
- Institut de Chimie Moléculaire de l'Université de Bourgogne-Franche-Comté; ICMUB-OCS (UMR CNRS 6302); 19 avenue A. Savary BP 47870 21078 Dijon CEDEX France
| | - Hassib Audi
- Institut de Chimie Moléculaire de l'Université de Bourgogne-Franche-Comté; ICMUB-OCS (UMR CNRS 6302); 19 avenue A. Savary BP 47870 21078 Dijon CEDEX France
| | - Pawel Jewula
- Institut de Chimie Moléculaire de l'Université de Bourgogne-Franche-Comté; ICMUB-OCS (UMR CNRS 6302); 19 avenue A. Savary BP 47870 21078 Dijon CEDEX France
| | - Radouane Koudih
- Institut de Chimie Moléculaire de l'Université de Bourgogne-Franche-Comté; ICMUB-OCS (UMR CNRS 6302); 19 avenue A. Savary BP 47870 21078 Dijon CEDEX France
| | - Raluca Malacea-Kabbara
- Institut de Chimie Moléculaire de l'Université de Bourgogne-Franche-Comté; ICMUB-OCS (UMR CNRS 6302); 19 avenue A. Savary BP 47870 21078 Dijon CEDEX France
| | - Delphine Vimont
- Department Institut des Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA-UMR CNRS 5287); 146 rue Léo Saignat 33076 Bordeaux CEDEX France
| | - Jürgen Schulz
- Department Institut des Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA-UMR CNRS 5287); 146 rue Léo Saignat 33076 Bordeaux CEDEX France
| | - Philippe Fernandez
- Department Institut des Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA-UMR CNRS 5287); 146 rue Léo Saignat 33076 Bordeaux CEDEX France
| | - Sylvain Jugé
- Institut de Chimie Moléculaire de l'Université de Bourgogne-Franche-Comté; ICMUB-OCS (UMR CNRS 6302); 19 avenue A. Savary BP 47870 21078 Dijon CEDEX France
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24
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Meyer JP, Adumeau P, Lewis JS, Zeglis BM. Click Chemistry and Radiochemistry: The First 10 Years. Bioconjug Chem 2016; 27:2791-2807. [PMID: 27787983 DOI: 10.1021/acs.bioconjchem.6b00561] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The advent of click chemistry has had a profound influence on almost all branches of chemical science. This is particularly true of radiochemistry and the synthesis of agents for positron emission tomography (PET), single photon emission computed tomography (SPECT), and targeted radiotherapy. The selectivity, ease, rapidity, and modularity of click ligations make them nearly ideally suited for the construction of radiotracers, a process that often involves working with biomolecules in aqueous conditions with inexorably decaying radioisotopes. In the following pages, our goal is to provide a broad overview of the first 10 years of research at the intersection of click chemistry and radiochemistry. The discussion will focus on four areas that we believe underscore the critical advantages provided by click chemistry: (i) the use of prosthetic groups for radiolabeling reactions, (ii) the creation of coordination scaffolds for radiometals, (iii) the site-specific radiolabeling of proteins and peptides, and (iv) the development of strategies for in vivo pretargeting. Particular emphasis will be placed on the four most prevalent click reactions-the Cu-catalyzed azide-alkyne cycloaddition (CuAAC), the strain-promoted azide-alkyne cycloaddition (SPAAC), the inverse electron demand Diels-Alder reaction (IEDDA), and the Staudinger ligation-although less well-known click ligations will be discussed as well. Ultimately, it is our hope that this review will not only serve to educate readers but will also act as a springboard, inspiring synthetic chemists and radiochemists alike to harness click chemistry in even more innovative and ambitious ways as we embark upon the second decade of this fruitful collaboration.
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Affiliation(s)
| | - Pierre Adumeau
- Department of Chemistry, Hunter College of the City University of New York , 413 East 69th Street, New York, New York 10028, United States
| | - Jason S Lewis
- Department of Radiology, Weill Cornell Medical College , 520 East 70th Street, New York, New York 10065, United States
| | - Brian M Zeglis
- Department of Chemistry, Hunter College of the City University of New York , 413 East 69th Street, New York, New York 10028, United States.,Department of Radiology, Weill Cornell Medical College , 520 East 70th Street, New York, New York 10065, United States.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York , 365 5th Avenue, New York, New York 10016, United States
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Zhang Q, Dall'Angelo S, Fleming IN, Schweiger LF, Zanda M, O'Hagan D. Last-Step Enzymatic [(18) F]-Fluorination of Cysteine-Tethered RGD Peptides Using Modified Barbas Linkers. Chemistry 2016; 22:10998-1004. [PMID: 27374143 DOI: 10.1002/chem.201601361] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 11/05/2022]
Abstract
We report a last-step fluorinase-catalyzed [(18) F]-fluorination of a cysteine-containing RGD peptide. The peptide was attached through sulfur to a modified and more hydrophilic variant of the recently disclosed Barbas linker which was itself linked to a chloroadenosine moiety via a PEGylated chain. The fluorinase was able to use this construct as a substrate for a transhalogenation reaction to generate [(18) F]-radiolabeled RGD peptides, which retained high affinity to cancer-cell relevant αv β3 integrins.
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Affiliation(s)
- Qingzhi Zhang
- School of Chemistry and Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK
| | - Sergio Dall'Angelo
- John Mallard Scottish PET Centre, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Ian N Fleming
- Aberdeen Biomedical Imaging Centre, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Lutz F Schweiger
- John Mallard Scottish PET Centre, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Matteo Zanda
- John Mallard Scottish PET Centre, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - David O'Hagan
- School of Chemistry and Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9ST, UK.
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Bernard-Gauthier V, Bailey JJ, Liu Z, Wängler B, Wängler C, Jurkschat K, Perrin DM, Schirrmacher R. From Unorthodox to Established: The Current Status of (18)F-Trifluoroborate- and (18)F-SiFA-Based Radiopharmaceuticals in PET Nuclear Imaging. Bioconjug Chem 2015; 27:267-79. [PMID: 26566577 DOI: 10.1021/acs.bioconjchem.5b00560] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Unorthodox (18)F-labeling strategies not employing the formation of a carbon-(18)F bond are seldom found in radiochemistry. Historically, the formation of a boron- or silicon-(18)F bond has been introduced very early on into the repertoire of labeling chemistries, but is without translation into any clinical radiotracer besides inorganic B[(18)F]F4(-) for brain tumor diagnosis. For many decades these labeling methodologies were forgotten and have just recently been revived by a handful of researchers thinking outside the box. When breaking with established paradigms such as the inability to obtain labeled compounds of high specific activity via isotopic exchange or performing radiofluorination in aqueous media, the research community often reacts skeptically. In 2005 and 2006, two novel labeling methodologies were introduced into radiochemistry for positron emission tomography (PET) tracer development: RBF3(-) labeling reported by Perrin et al. and the SiFA methodology by Schirrmacher, Jurkschat, and Waengler et al. which is based on isotopic exchange (IE). Both labeling methodologies have been complemented by other noncanonical strategies to introduce (18)F into biomolecules of diagnostic importance, thus profoundly enriching the landscape of (18)F radiolabeling. B- and Si-based labeling strategies finally revealed that IE is a viable alternative to established and traditional radiochemistry with the advantage of simplifying both the labeling effort as well as the necessary purification of the radiotracer. Hence IE will be the focus of this contribution over other noncanonical labeling methods. Peptides for tumor imaging especially lend themselves favorably toward one-step labeling via IE, but small molecules have been described as well, taking advantage of these new approaches, and have been used successfully for brain imaging. This Review gives an account of both radiochemistries centered on boron and silicon, describing the very beginnings of their basic research, the path that led to optimization of their chemistries, and the first encouraging preclinical results paving the way to their clinical use. This side by side approach will give the reader the opportunity to follow the development of a new basic discovery into a clinically applicable radiotracer including all the hurdles that have had to be overcome.
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Affiliation(s)
- Vadim Bernard-Gauthier
- Division of Oncological Imaging, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Justin J Bailey
- Division of Oncological Imaging, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
| | - Zhibo Liu
- Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health , 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | | | | | - Klaus Jurkschat
- Department of Chemistry and Chemical Biology, Technical University of Dortmund , 44227 Dortmund, Germany
| | - David M Perrin
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ralf Schirrmacher
- Division of Oncological Imaging, Department of Oncology, University of Alberta , 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada
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Chansaenpak K, Vabre B, Gabbaï FP. [(18)F]-Group 13 fluoride derivatives as radiotracers for positron emission tomography. Chem Soc Rev 2015; 45:954-71. [PMID: 26548467 DOI: 10.1039/c5cs00687b] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The field of (18)F chemistry is rapidly expanding because of the use of this radionuclide in radiotracers for positron emission tomography (PET). Until recently, most [(18)F]-radiotracers were generated by the direct attachment of (18)F to a carbon in the organic backbone of the radiotracer. The past decade has witnessed the emergence of a new strategy based on the formation of an (18)F-group 13 element bond. This approach, which is rooted in the field of fluoride anion complexation/coordination chemistry, has led to the development of a remarkable family of boron, aluminium and gallium [(18)F]-fluoride anion complexing agents which can be conjugated with peptides and small molecules to generate disease specific PET radiotracers. This review is dedicated to the chemistry of these group 13 [(18)F]-fluorides anion complexing agents and their use in PET. Some of the key fluoride-binding motifs covered in this review include the trifluoroborate unit bound to neutral or cationic electron deficient backbones, the BF2 unit of BODIPY dyes, and AlF or GaF3 units coordinated to multidentate Lewis basic ligands. In addition to describing how these moieties can be converted into their [(18)F]-analogs, this review also dicusses their incorporation into bioconjugates for application in PET.
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Affiliation(s)
- Kantapat Chansaenpak
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
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Litau S, Niedermoser S, Vogler N, Roscher M, Schirrmacher R, Fricker G, Wängler B, Wängler C. Next Generation of SiFAlin-Based TATE Derivatives for PET Imaging of SSTR-Positive Tumors: Influence of Molecular Design on In Vitro SSTR Binding and In Vivo Pharmacokinetics. Bioconjug Chem 2015; 26:2350-9. [PMID: 26420336 DOI: 10.1021/acs.bioconjchem.5b00510] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Silicon-Fluoride-Acceptor (SiFA)-(18)F-labeling strategy has been shown before to enable the straightforward and efficient (18)F-labeling of complex biologically active substances such as proteins and peptides. Especially in the case of peptides, the radiolabeling proceeds kit-like in short reaction times and without the need of complex product workup. SiFA-derivatized, (18)F-labeled Tyr(3)-octreotate (TATE) derivatives demonstrated, besides strong somatostatin receptor (SSTR) binding, favorable in vivo pharmacokinetics as well as excellent tumor visualization by PET imaging. In this study, we intended to determine the influence of the underlying molecular design and used molecular scaffolds of SiFAlin-TATE derivatives on SSTR binding as well as on the in vivo pharmacokinetics of the resulting (18)F-labeled peptides. For this purpose, new SiFAlin-(Asp)n-PEG1-TATE analogs (where n = 1-4) were synthesized, efficiently radiolabeled with (18)F in a kit-like manner and obtained in radiochemical yields of 70-80%, radiochemical purities of ≥97%, and nonoptimized specific activities of 20.1-45.2 GBq/μmol within 20-25 min starting from 0.7-1.5 GBq of (18)F. In the following, the radiotracer's lipophilicities and stabilities in human serum were determined. Furthermore, the SSTR-specific binding affinities were evaluated by a competitive displacement assay on SSTR-positive AR42J cells. The obtained in vitro results support the assumption that aspartic acids are able to considerably increase the radiotracer's hydrophilicity and that their number does not affect the SSTR binding potential of the TATE derivatives. The most promising tracer (18)F-SiFAlin-Asp3-PEG1-TATE [(18)F]6 (LogD = -1.23 ± 0.03, IC50 = 20.7 ± 2.5 nM) was further evaluated in vivo in AR42J tumor-bearing nude mice via PET/CT imaging against the clinical gold standard (68)Ga-DOTATATE as well as the previously developed SiFAlin-TATE derivative [(18)F]3. The results of these evaluations showed that [(18)F]6-although showing very similar chemical and in vitro properties to [(18)F]3-exhibits not only a slowed renal clearance compared to [(18)F]3, but also a higher absolute tumor uptake compared to (68)Ga-DOTATATE, and furthermore enables excellent tumor visualization with high image resolution. These results emphasize the importance of systematic study of the influence of molecular design and applied structure elements of peptidic radiotracers, as these may considerably influence in vivo pharmacokinetics while not affecting other parameters such as radiochemistry, lipophilicity, serum stability, or receptor binding potential.
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Affiliation(s)
| | | | | | | | - R Schirrmacher
- Department of Oncology, Division of Oncological Imaging, University of Alberta , Edmonton T6G 2R3, Canada
| | - G Fricker
- Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg , 69117 Heidelberg, Germany
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Methods to Increase the Metabolic Stability of (18)F-Radiotracers. Molecules 2015; 20:16186-220. [PMID: 26404227 PMCID: PMC6332123 DOI: 10.3390/molecules200916186] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/20/2015] [Accepted: 08/26/2015] [Indexed: 11/17/2022] Open
Abstract
The majority of pharmaceuticals and other organic compounds incorporating radiotracers that are considered foreign to the body undergo metabolic changes in vivo. Metabolic degradation of these drugs is commonly caused by a system of enzymes of low substrate specificity requirement, which is present mainly in the liver, but drug metabolism may also take place in the kidneys or other organs. Thus, radiotracers and all other pharmaceuticals are faced with enormous challenges to maintain their stability in vivo highlighting the importance of their structure. Often in practice, such biologically active molecules exhibit these properties in vitro, but fail during in vivo studies due to obtaining an increased metabolism within minutes. Many pharmacologically and biologically interesting compounds never see application due to their lack of stability. One of the most important issues of radiotracers development based on fluorine-18 is the stability in vitro and in vivo. Sometimes, the metabolism of 18F-radiotracers goes along with the cleavage of the C-F bond and with the rejection of [18F]fluoride mostly combined with high background and accumulation in the skeleton. This review deals with the impact of radiodefluorination and with approaches to stabilize the C-F bond to avoid the cleavage between fluorine and carbon.
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Richter S, Wuest F. 18F-Labeled Peptides: The Future Is Bright. Molecules 2014; 19:20536-20556. [PMID: 25493636 PMCID: PMC6271677 DOI: 10.3390/molecules191220536] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 11/24/2014] [Accepted: 11/28/2014] [Indexed: 01/10/2023] Open
Abstract
Radiolabeled peptides have been the subject of intense research efforts for targeted diagnostic imaging and radiotherapy over the last 20 years. Peptides offer several advantages for receptor imaging and targeted radiotherapy. The low molecular weight of peptides allows for rapid clearance from the blood and non-target tissue, which results in favorable target-to-non-target ratios. Moreover, peptides usually display good tissue penetration and they are generally non-immunogenic. A major drawback is their potential low metabolic stability. The majority of currently used radiolabeled peptides for targeted molecular imaging and therapy of cancer is labeled with various radiometals like 99mTc, 68Ga, and 177Lu. However, over the last decade an increasing number of 18F-labeled peptides have been reported. Despite of obvious advantages of 18F like its ease of production in large quantities at high specific activity, the low β+ energy (0.64 MeV) and the favorable half-life (109.8 min), 18F-labeling of peptides remains a special challenge. The first part of this review will provide a brief overview on chemical strategies for peptide labeling with 18F. A second part will discuss recent technological advances for 18F-labeling of peptides with special focus on microfluidic technology, automation, and kit-like preparation of 18F-labeled peptides.
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Affiliation(s)
- Susan Richter
- Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada.
| | - Frank Wuest
- Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, AB T6G 1Z2, Canada.
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Ermert J. 18F-labelled intermediates for radiosynthesis by modular build-up reactions: newer developments. BIOMED RESEARCH INTERNATIONAL 2014; 2014:812973. [PMID: 25343144 PMCID: PMC4197889 DOI: 10.1155/2014/812973] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 05/12/2014] [Indexed: 12/20/2022]
Abstract
This brief review gives an overview of newer developments in (18)F-chemistry with the focus on small (18)F-labelled molecules as intermediates for modular build-up syntheses. The short half-life (<2 h) of the radionuclide requires efficient syntheses of these intermediates considering that multistep syntheses are often time consuming and characterized by a loss of yield in each reaction step. Recent examples of improved synthesis of (18)F-labelled intermediates show new possibilities for no-carrier-added ring-fluorinated arenes, novel intermediates for tri[(18)F]fluoromethylation reactions, and (18)F-fluorovinylation methods.
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Affiliation(s)
- Johannes Ermert
- Institut für Neurowissenschaften und Medizin, INM-5: Nuklearchemie, Forschungszentrum Jülich, 52425 Jülich, Germany
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Sweetening pharmaceutical radiochemistry by (18)f-fluoroglycosylation: a short review. BIOMED RESEARCH INTERNATIONAL 2014; 2014:214748. [PMID: 24991541 PMCID: PMC4058687 DOI: 10.1155/2014/214748] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 04/15/2014] [Indexed: 12/20/2022]
Abstract
At the time when the highly efficient [(18)F]FDG synthesis was discovered by the use of the effective precursor 1,3,4,6-tetra-O-acetyl-2-O-trifluoromethanesulfonyl- β -D-mannopyranose (mannose triflate) for nucleophilic (18)F-substitution, the field of PET in nuclear medicine experienced a long-term boom. Thirty years later, various strategies for chemoselective (18)F-labeling of biomolecules have been developed, trying to keep up with the emerging field of radiopharmaceutical sciences. Among the new radiochemical strategies, chemoselective (18)F-fluoroglycosylation methods aim at the sweetening of pharmaceutical radiochemistry by providing a powerful and highly valuable tool for the design of (18)F-glycoconjugates with suitable in vivo properties for PET imaging studies. This paper provides a short review (reflecting the literature not older than 8 years) on the different (18)F-fluoroglycosylation reactions that have been applied to the development of various (18)F-glycoconjugate tracers, including not only peptides, but also nonpeptidic tracers and high-molecular-weight proteins.
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