The use of radiolabelled antibodies and antibody-derived recombinant constructs has shown promise for both imaging and therapeutic use. In this context, the biotin-avidin/streptavidin pairing, along with the inverse-electron-demand Diels-Alder (iEDDA) reaction, have found application in pretargeting approaches for positron emission tomography (PET). This study reports the fluorinase-mediated transhalogenation [5'-chloro-5'-deoxyadenosine (ClDA) substrates to 5'-fluoro-5'-deoxyadenosine (FDA) products] of two antibody pretargeting tools, a FDA-PEG-tetrazine and a [ F]FDA-PEG-biotin, and each is assessed either for its compatibility towards iEDDA ligation to trans-cyclooctene or for its affinity to avidin. A protocol to avoid radiolytically promoted oxidation of biotin during the synthesis of [ F]FDA-PEG-biotin was developed. The study adds to the repertoire of conjugates for use in fluorinase-catalysed radiosynthesis for PET and shows that the fluorinase will accept a wide range of ClDA substrates tethered at C-2 of the adenine ring with a PEGylated cargo. The method is exceptional because the nucleophilic reaction with [ F]fluoride takes place in water at neutral pH and at ambient temperature.
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http://dx.doi.org/10.1002/cbic.201800234 | DOI Listing |
J Am Chem Soc
January 2025
Laboratoire de Chimie Supramoléculaire, Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg, Strasbourg 67000, France.
SAr reactions were remarkably accelerated using a pretargeting and activating unit based on dynamic covalent chemistry (DCvC). A Cys attack at the C-F bond on the aromatic ring of salicylaldehyde derivatives was only observed upon iminium formation with a neighboring Lys residue of model small peptides. Such self-activation was ascribed to the stronger electron-withdrawing capability of the iminium bond with respect to that of the parent aldehyde that stabilized the transition state of the reaction, together with the higher preorganization of the reactive groups in the cationic aldiminium species.
View Article and Find Full Text PDFNucl Med Biol
November 2024
Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Pharmacology, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, USA; Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA. Electronic address:
Background: Peritoneal metastasis with micrometastatic cell clusters is a common feature of advanced ovarian cancer. Targeted alpha therapy (TAT) is an attractive approach for treating micrometastatic diseases as alpha particles release enormous amounts of energy within a short distance. A pretargeting approach - leveraging the inverse-electron-demand Diels-Alder reaction between tetrazines (Tz) and trans-cyclooctene (TCO) - can minimize off-target toxicity related to TAT, often associated with full-length antibodies.
View Article and Find Full Text PDFJ Labelled Comp Radiopharm
November 2024
Department of Life Sciences, University of Bath, Bath, UK.
The rise of nucleic acid-based therapeutics continues apace. At the same time, the need for radiolabelled oligonucleotides for determination of spatial distribution is increasing. Complex molecular structures with mostly multiple charges and low solubility in organic solvents increase the challenge of integrating radionuclides.
View Article and Find Full Text PDFChemistry
January 2025
The Key Laboratory of Carbohydrate Chemistry & Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
Enhancing the Fc effector functions of monoclonal antibodies (mAbs) is a proven strategy for improving cancer immunotherapy. In this study, we present a novel pre-targeting approach that integrates host-guest chemistry with an antibody-recruiting concept to create mAbs with superior effector functions. Using rituximab (RTX), a clinically approved anti-CD20 mAb, as our model, we modified RTX by conjugating it with adamantane (Ada) derivatives and various polyethylene glycol (PEG) linkers to produce RTX-Ada conjugates.
View Article and Find Full Text PDFNat Commun
October 2024
Department of Psychology, New York University, New York, NY, USA.
We can often anticipate the precise moment when a stimulus will be relevant for our behavioral goals. Voluntary temporal attention, the prioritization of sensory information at task-relevant time points, enhances visual perception. However, the neural mechanisms of voluntary temporal attention have not been isolated from those of temporal expectation, which reflects timing predictability rather than relevance.
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