64Cu tumor labeling with hexadentate picolinic acid-based bispidine immunoconjugates

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Manja Kubeil - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Christin Neuber - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Miriam Starke - , Heidelberg University  (Author)
  • Claudia Arndt - , Helmholtz-Zentrum Dresden-Rossendorf, Medical Faculty Carl Gustav Carus, TUD Dresden University of Technology (Author)
  • Liliana Rodrigues Loureiro - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Lydia Hoffmann - , Helmholtz-Zentrum Dresden-Rossendorf (Author)
  • Anja Feldmann - , Helmholtz-Zentrum Dresden-Rossendorf, University Hospital Carl Gustav Carus Dresden, German Cancer Research Center (DKFZ), National Center for Tumor Diseases (NCT) Dresden (Author)
  • Michael Bachmann - , National Center for Tumor Diseases Dresden (NCT/UCC), German Cancer Consortium (Partner: DKTK, DKFZ), Helmholtz-Zentrum Dresden-Rossendorf, University Hospital Carl Gustav Carus Dresden, German Cancer Research Center (DKFZ) (Author)
  • Jens Pietzsch - , Helmholtz-Zentrum Dresden-Rossendorf, TUD Dresden University of Technology (Author)
  • Peter Comba - , Heidelberg University  (Author)
  • Holger Stephan - , Helmholtz-Zentrum Dresden-Rossendorf (Author)

Abstract

Discussed are two picolinate appended bispidine ligands (3,7-diazabicyclo[3.3.1]nonane derivatives) in comparison with an earlier described bis-pyridine derivative, which are all known to strongly bind CuII. The radiopharmacological characterization of the two isomeric bispidine complexes includes quantitative labeling with 64CuII at ambient conditions with high radiochemical purities and yields (molar activities >200 MBq/nmol). Challenge experiments in presence of EDTA, cyclam, human serum and SOD demonstrate high stability and inertness of the 64Cu-bispidine complexes. Biodistribution studies performed in Wistar rats indicate a rapid renal elimination for both 64Cu-labeled chelates. The bispidine ligand with the picolinate group in N7 position was selected for further biological experiments, and its backbone was therefore substituted with a benzyl-NCS group at C9. Two tumor target modules (TMs), targeting prostate stem cell antigen (PSCA), overexpressed in prostate cancer, and the fibroblast activation protein (FAP) in fibrosarcoma, were selected for thiourea coupling with the NCS-functionalized ligand and lysine residues of TMs. Small animal PET experiments on tumor-bearing mice showed specific accumulation of the 64Cu-labeled TMs in PSCA- and FAP-overexpressing tumors (standardized uptake value (SUV) for PC3: 2.7±0.6 and HT1080: 7.2±1.25) with almost no uptake in wild type tumors.

Details

Original languageEnglish
Article numbere202400366
JournalChemistry - A European Journal
Volume30
Issue number32
Publication statusPublished - 6 Jun 2024
Peer-reviewedYes

External IDs

PubMed 38506263

Keywords

Sustainable Development Goals

Keywords

  • Cu-labeling, bispidine, fibroblast activation protein (FAP), PET imaging, prostate stem cell antigen (PSCA)