1. 'Clickable' Albumin Binders for Modulating the Tumor Uptake of Targeted Radiopharmaceuticals
- Author
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Florian Brandt, Martin Ullrich, Markus Laube, Klaus Kopka, Michael Bachmann, Reik Löser, Jens Pietzsch, Hans-Jürgen Pietzsch, Jörg van den Hoff, and Robert Wodtke
- Subjects
Lysine ,Xenograft Model Antitumor Assays ,Mice ,Structure-Activity Relationship ,Copper Radioisotopes ,Albumins ,Neoplasms ,Positron-Emission Tomography ,Drug Discovery ,Animals ,Molecular Medicine ,Tissue Distribution ,Radiopharmaceuticals ,Protein Binding - Abstract
The intentional binding of radioligands to albumin gains increasing attention in the context of radiopharmaceutical cancer therapy as it can lead to an enhanced radioactivity uptake into the tumor lesions and thus, to a potentially improved therapeutic outcome. However, the influence of the radioligand’s albumin binding affinity on the time profile of tumor uptake depending on the particular albumin-binding affinity have been only partly addressed so far. Based on the previously identified Nε-4-(4-iodophenyl)butanoyl-lysine scaffold, we designed “clickable” lysine-derived albumin binders (cLABs) and determined their dissociation constants towards albumin by novel assay methods. Structure-activity relationships were derived and selected cLABs were applied for the modification of the somatostatin receptor subtype-2 ligand (Tyr³)octreotate (TATE). These novel conjugates were radiolabeled with copper-64 and subjected to a detailed in vitro and in vivo radiopharmacological characterization. Overall, the results of this study provide an incentive for further investigations of albumin binders for applications in endoradionuclide therapies.
- Published
- 2021