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Tripathy RK, Pande AH. Molecular and functional insight into anti-EGFR nanobody: Theranostic implications for malignancies. Life Sci 2024; 345:122593. [PMID: 38554946 DOI: 10.1016/j.lfs.2024.122593] [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] [Received: 01/09/2024] [Revised: 02/27/2024] [Accepted: 03/24/2024] [Indexed: 04/02/2024]
Abstract
Targeted therapy and imaging are the most popular techniques for the intervention and diagnosis of cancer. A potential therapeutic target for the treatment of cancer is the epidermal growth factor receptor (EGFR), primarily for glioblastoma, lung, and breast cancer. Over-production of ligand, transcriptional up-regulation due to autocrine/paracrine signalling, or point mutations at the genomic locus may contribute to the malfunction of EGFR in malignancies. This exploit makes use of EGFR, an established biomarker for cancer diagnostics and treatment. Despite considerable development in the last several decades in making EGFR inhibitors, they are still not free from limitations like toxicity and a short serum half-life. Nanobodies and antibodies share similar binding properties, but nanobodies have the additional advantage that they can bind to antigenic epitopes deep inside the target that conventional antibodies are unable to access. For targeted therapy, anti-EGFR nanobodies can be conjugated to various molecules such as drugs, peptides, toxins and photosensitizers. These nanobodies can be designed as novel immunoconjugates using the universal modular antibody-based platform technology (UniCAR). Furthermore, Anti-EGFR nanobodies can be expressed in neural stem cells and visualised by effective fluorescent and radioisotope labelling.
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Affiliation(s)
- Rajan K Tripathy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, (Mohali) 160062, Punjab, India
| | - Abhay H Pande
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, (Mohali) 160062, Punjab, India.
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De Leiris N, Perret P, Lombardi C, Gözel B, Chierici S, Millet P, Debiossat M, Bacot S, Tournier BB, Chames P, Lenormand JL, Ghezzi C, Fagret D, Moulin M. A single-domain antibody for the detection of pathological Tau protein in the early stages of oligomerization. J Transl Med 2024; 22:163. [PMID: 38365700 PMCID: PMC10870657 DOI: 10.1186/s12967-024-04987-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/12/2024] [Indexed: 02/18/2024] Open
Abstract
BACKGROUND Soluble oligomeric forms of Tau protein have emerged as crucial players in the propagation of Tau pathology in Alzheimer's disease (AD). Our objective is to introduce a single-domain antibody (sdAb) named 2C5 as a novel radiotracer for the efficient detection and longitudinal monitoring of oligomeric Tau species in the human brain. METHODS The development and production of 2C5 involved llama immunization with the largest human Tau isoform oligomers of different maturation states. Subsequently, 2C5 underwent comprehensive in vitro characterization for affinity and specificity via Enzyme-Linked Immunosorbent Assay and immunohistochemistry on human brain slices. Technetium-99m was employed to radiolabel 2C5, followed by its administration to healthy mice for biodistribution analysis. RESULTS 2C5 exhibited robust binding affinity towards Tau oligomers (Kd = 6.280 nM ± 0.557) and to Tau fibers (Kd = 5.024 nM ± 0.453), with relatively weaker binding observed for native Tau protein (Kd = 1791 nM ± 8.714) and amyloid peptide (Kd > 10,000 nM). Remarkably, this SdAb facilitated immuno-histological labeling of pathological forms of Tau in neurons and neuritic plaques, yielding a high-contrast outcome in AD patients, closely mirroring the performance of reference antibodies AT8 and T22. Furthermore, 2C5 SdAb was successfully radiolabeled with 99mTc, preserving stability for up to 6 h post-radiolabeling (radiochemical purity > 93%). However, following intravenous injection into healthy mice, the predominant uptake occurred in kidneys, amounting to 115.32 ± 3.67, 97.70 ± 43.14 and 168.20 ± 34.52% of injected dose per gram (% ID/g) at 5, 10 and 45 min respectively. Conversely, brain uptake remained minimal at all measured time points, registering at 0.17 ± 0.03, 0.12 ± 0.07 and 0.02 ± 0.01% ID/g at 5, 10 and 45 min post-injection respectively. CONCLUSION 2C5 demonstrates excellent affinity and specificity for pathological Tau oligomers, particularly in their early stages of oligomerization. However, the current limitation of insufficient blood-brain barrier penetration necessitates further modifications before considering its application in nuclear medicine imaging for humans.
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Affiliation(s)
- Nicolas De Leiris
- University Grenoble Alpes, Clinique Universitaire de Médecine Nucléaire, INSERM, Centre Hospitalier Universitaire Grenoble Alpes, LRB, CS 10217, 38043, Grenoble CEDEX 9, France.
| | - Pascale Perret
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | | | - Bülent Gözel
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | - Sabine Chierici
- University Grenoble Alpes, CNRS, DCM, 38000, Grenoble, France
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
| | | | - Sandrine Bacot
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, Geneva University Hospitals, Geneva, Switzerland
| | - Patrick Chames
- Aix Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille, France
| | | | | | - Daniel Fagret
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
| | - Marcelle Moulin
- University Grenoble Alpes, INSERM, LRB, 38000, Grenoble, France
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3
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Rochet LNC, Bahou C, Wojciechowski JP, Koutsopetras I, Britton P, Spears RJ, Thanasi IA, Shao B, Zhong L, Bučar DK, Aliev AE, Porter MJ, Stevens MM, Baker JR, Chudasama V. Use of pyridazinediones for tuneable and reversible covalent cysteine modification applied to peptides, proteins and hydrogels. Chem Sci 2023; 14:13743-13754. [PMID: 38075666 PMCID: PMC10699563 DOI: 10.1039/d3sc04976k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/27/2023] [Indexed: 05/02/2024] Open
Abstract
Reversible cysteine modification has been found to be a useful tool for a plethora of applications such as selective enzymatic inhibition, activity-based protein profiling and/or cargo release from a protein or a material. However, only a limited number of reagents display reliable dynamic/reversible thiol modification and, in most cases, many of these reagents suffer from issues of stability, a lack of modularity and/or poor rate tunability. In this work, we demonstrate the potential of pyridazinediones as novel reversible and tuneable covalent cysteine modifiers. We show that the electrophilicity of pyridazinediones correlates to the rates of the Michael addition and retro-Michael deconjugation reactions, demonstrating that pyridazinediones provide an enticing platform for readily tuneable and reversible thiol addition/release. We explore the regioselectivity of the novel reaction and unveil the reason for the fundamental increased reactivity of aryl bearing pyridazinediones by using DFT calculations and corroborating findings with SCXRD. We also applied this fundamental discovery to making more rapid disulfide rebridging agents in related work. We finally provide the groundwork for potential applications in various areas with exemplification using readily functionalised "clickable" pyridazinediones on clinically relevant cysteine and disulfide conjugated proteins, as well as on a hydrogel material.
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Affiliation(s)
- Léa N C Rochet
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Calise Bahou
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Jonathan P Wojciechowski
- Department of Materials, Department of Bioengineering, Institute of Biomedical Engineering, Imperial College London London SW7 2AZ UK
| | - Ilias Koutsopetras
- Bio-Functional Chemistry (UMR 7199), Institut du Médicament de Strasbourg, University of Strasbourg 74 Route du Rhin 67400 Illkirch-Graffenstaden France
| | - Phyllida Britton
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Richard J Spears
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Ioanna A Thanasi
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Baihao Shao
- Department of Materials, Department of Bioengineering, Institute of Biomedical Engineering, Imperial College London London SW7 2AZ UK
| | - Lisha Zhong
- Department of Materials, Department of Bioengineering, Institute of Biomedical Engineering, Imperial College London London SW7 2AZ UK
| | - Dejan-Krešimir Bučar
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Abil E Aliev
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Michael J Porter
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Molly M Stevens
- Department of Materials, Department of Bioengineering, Institute of Biomedical Engineering, Imperial College London London SW7 2AZ UK
| | - James R Baker
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
| | - Vijay Chudasama
- Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK
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Frecot DI, Froehlich T, Rothbauer U. 30 years of nanobodies - an ongoing success story of small binders in biological research. J Cell Sci 2023; 136:jcs261395. [PMID: 37937477 DOI: 10.1242/jcs.261395] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023] Open
Abstract
A milestone in the field of recombinant binding molecules was achieved 30 years ago with the discovery of single-domain antibodies from which antigen-binding variable domains, better known as nanobodies (Nbs), can be derived. Being only one tenth the size of conventional antibodies, Nbs feature high affinity and specificity, while being highly stable and soluble. In addition, they display accessibility to cryptic sites, low off-target accumulation and deep tissue penetration. Efficient selection methods, such as (semi-)synthetic/naïve or immunized cDNA libraries and display technologies, have facilitated the isolation of Nbs against diverse targets, and their single-gene format enables easy functionalization and high-yield production. This Review highlights recent advances in Nb applications in various areas of biological research, including structural biology, proteomics and high-resolution and in vivo imaging. In addition, we provide insights into intracellular applications of Nbs, such as live-cell imaging, biosensors and targeted protein degradation.
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Affiliation(s)
- Desiree I Frecot
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstrasse 55, 72770 Reutlingen, Reutlingen, Germany
| | - Theresa Froehlich
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
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5
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Hurley K, Cao M, Huang H, Wang Y. Targeted Alpha Therapy (TAT) with Single-Domain Antibodies (Nanobodies). Cancers (Basel) 2023; 15:3493. [PMID: 37444603 DOI: 10.3390/cancers15133493] [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: 05/30/2023] [Revised: 06/23/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
The persistent threat of cancer necessitates the development of improved and more efficient therapeutic strategies that limit damage to healthy tissues. Targeted alpha therapy (TαT), a novel form of radioimmuno-therapy (RIT), utilizes a targeting vehicle, commonly antibodies, to deliver high-energy, but short-range, alpha-emitting particles specifically to cancer cells, thereby reducing toxicity to surrounding normal tissues. Although full-length antibodies are often employed as targeting vehicles for TαT, their high molecular weight and the presence of an Fc-region lead to a long blood half-life, increased bone marrow toxicity, and accumulation in other tissues such as the kidney, liver, and spleen. The discovery of single-domain antibodies (sdAbs), or nanobodies, naturally occurring in camelids and sharks, has introduced a novel antigen-specific vehicle for molecular imaging and TαT. Given that nanobodies are the smallest naturally occurring antigen-binding fragments, they exhibit shorter relative blood half-lives, enhanced tumor uptake, and equivalent or superior binding affinity and specificity. Nanobody technology could provide a viable solution for the off-target toxicity observed with full-length antibody-based TαT. Notably, the pharmacokinetic properties of nanobodies align better with the decay characteristics of many short-lived α-emitting radionuclides. This review aims to encapsulate recent advancements in the use of nanobodies as a vehicle for TαT.
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Affiliation(s)
- Kate Hurley
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Meiyun Cao
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
| | - Haiming Huang
- Research Center, Forlong Biotechnology Inc., Suzhou 215004, China
| | - Yi Wang
- Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, ON K0J 1J0, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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6
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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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Sidorenko GV, Miroslavov AE, Tyupina MY. Technetium(I) carbonyl complexes for nuclear medicine: Coordination-chemical aspect. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Mulero F, Oteo M, Garaulet G, Magro N, Rebollo L, Medrano G, Santiveri C, Romero E, Sellek RE, Margolles Y, Campos-Olivas R, Arroyo AG, Fernández LA, Morcillo MA, Martínez-Torrecuadrada JL. Development of anti-membrane type 1-matrix metalloproteinase nanobodies as immunoPET probes for triple negative breast cancer imaging. Front Med (Lausanne) 2022; 9:1058455. [PMID: 36507540 PMCID: PMC9729729 DOI: 10.3389/fmed.2022.1058455] [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: 09/30/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
Triple-negative breast cancer (TNBC) is characterized by aggressiveness and high rates of metastasis. The identification of relevant biomarkers is crucial to improve outcomes for TNBC patients. Membrane type 1-matrix metalloproteinase (MT1-MMP) could be a good candidate because its expression has been reported to correlate with tumor malignancy, progression and metastasis. Moreover, single-domain variable regions (VHHs or Nanobodies) derived from camelid heavy-chain-only antibodies have demonstrated improvements in tissue penetration and blood clearance, important characteristics for cancer imaging. Here, we have developed a nanobody-based PET imaging strategy for TNBC detection that targets MT1-MMP. A llama-derived library was screened against the catalytic domain of MT1-MMP and a panel of specific nanobodies were identified. After a deep characterization, two nanobodies were selected to be labeled with gallium-68 (68Ga). ImmunoPET imaging with both ([68Ga]Ga-NOTA-3TPA14 and [68Ga]Ga-NOTA-3CMP75) in a TNBC mouse model showed precise tumor-targeting capacity in vivo with high signal-to-background ratios. (68Ga)Ga-NOTA-3CMP75 exhibited higher tumor uptake compared to (68Ga)Ga-NOTA-3TPA14. Furthermore, imaging data correlated perfectly with the immunohistochemistry staining results. In conclusion, we found a promising candidate for nanobody-based PET imaging to be further investigated as a diagnostic tool in TNBC.
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Affiliation(s)
- Francisca Mulero
- Molecular Imaging Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Marta Oteo
- Medical Applications of Ionizing Radiations Unit, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - Guillermo Garaulet
- Molecular Imaging Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Natalia Magro
- Medical Applications of Ionizing Radiations Unit, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - Lluvia Rebollo
- Protein Production Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Guillermo Medrano
- Molecular Imaging Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Clara Santiveri
- Spectroscopy and Nuclear Magnetic Resonance Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Eduardo Romero
- Medical Applications of Ionizing Radiations Unit, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - Ricela E. Sellek
- Medical Applications of Ionizing Radiations Unit, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | - Yago Margolles
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, (CNB-CSIC), Madrid, Spain
| | - Ramón Campos-Olivas
- Spectroscopy and Nuclear Magnetic Resonance Unit, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Alicia G. Arroyo
- Department of Molecular Biomedicine, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), Madrid, Spain
| | - Luis Angel Fernández
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, (CNB-CSIC), Madrid, Spain
| | - Miguel Angel Morcillo
- Medical Applications of Ionizing Radiations Unit, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain,*Correspondence: Miguel Angel Morcillo,
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Feng Y, Sarrett SM, Meshaw RL, Vaidyanathan G, Cornejo MA, Zeglis BM, Zalutsky MR. Site-Specific Radiohalogenation of a HER2-Targeted Single-Domain Antibody Fragment Using a Novel Residualizing Prosthetic Agent. J Med Chem 2022; 65:15358-15373. [PMID: 36368007 DOI: 10.1021/acs.jmedchem.2c01331] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Because of their rapid tumor accumulation and normal tissue clearance, single-domain antibody fragments (sdAbs) are an attractive vehicle for developing radiotherapeutics labeled with the α-emitter 211At. Herein, we have evaluated iso-[211At]AGMB-PODS, a prosthetic agent that combines a functionality for residualizing radiohalogens with a phenyloxadiazolyl methylsulfone (PODS) moiety for site-specific sdAb conjugation. Iso-[211At]AGMB-PODS and its radioiodinated analogue were evaluated for thiol-selective conjugation to anti-HER2 5F7 sdAb bearing a C-terminus GGC tail. Both radiohalogenated PODS-5F7GGC conjugates were synthesized in good radiochemical yields and retained high binding affinity on HER2-positive BT474 breast carcinoma cells. Iso-[211At]AGMB-PODS-5F7GGC was considerably more stable in vitro than its maleimide analogue in the presence of cysteine and human serum albumin (HSA) and exhibited excellent tumor uptake and high in vivo stability. Superior tumor-to-kidney activity ratios were seen for both radiohalogenated PODS-5F7GGC conjugates compared with [177Lu]Lu-DOTA-PODS-5F7GGC. These results suggest that iso-[211At]AGMB-PODS-5F7GGC warrants further evaluation for the treatment of HER2-expressing malignancies.
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Affiliation(s)
- Yutian Feng
- Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Samantha M. Sarrett
- Hunter College, City University of New York, New York, New York 10021, United States
- Ph.D. Programs in Biochemistry and Chemistry, The Graduate Center, City University of New York, New York, New York 10021, United States
| | - Rebecca L. Meshaw
- Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Ganesan Vaidyanathan
- Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Mike A. Cornejo
- Hunter College, City University of New York, New York, New York 10021, United States
- Ph.D. Programs in Biochemistry and Chemistry, The Graduate Center, City University of New York, New York, New York 10021, United States
| | - Brian M. Zeglis
- Hunter College, City University of New York, New York, New York 10021, United States
- Ph.D. Programs in Biochemistry and Chemistry, The Graduate Center, City University of New York, New York, New York 10021, United States
| | - Michael R. Zalutsky
- Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, United States
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Fully automated 18F-fluorination of N-succinimidyl-4-[ 18F]fluorobenzoate ([ 18F]SFB) for indirect labelling of nanobodies. Sci Rep 2022; 12:18655. [PMID: 36333403 PMCID: PMC9636270 DOI: 10.1038/s41598-022-23552-8] [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: 09/05/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022] Open
Abstract
N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB), a widely used labeling agent to introduce the 4-[18F]fluorobenzoyl-prosthetic group, is normally obtained in three consecutive steps from [18F]fluoride ion. Here, we describe an efficient one-step labeling procedure of [18F]SFB starting from a tin precursor. This method circumvents volatile radioactive side-products and simplifies automatization. [18F]SFB was obtained after HPLC purification in a yield of 42 + 4% and a radiochemical purity (RCP) > 99% (n = 6). In addition, we investigate the automation of the coupling of [18F]SFB to a nanobody (cAbBcII10, targeting β-lactamase enzyme) and purification by size exclusion chromatography (PD-10 desalting column) to remove unconjugated reagent. Production and use of [18F]SFB were implemented on a radiosynthesis unit (Neptis®). The fully automated radiosynthesis process including purification and formulation required 160 min of synthesis time. [18F]SFB-labeled nanobody was obtained in a yield of 21 + 2% (activity yield 12 + 1% non-decay corrected) and a radiochemical purity (RCP) of > 95% (n = 3). This approach simplifies [18F]SFB synthesis to one-step, enhances the yield in comparison to the previous report and enables the production of radiolabeled nanobody on the same synthesis module.
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