Exceptionally fast formation of stable rigidified cross-bridged complexes formed with Cu(ii) isotopes for molecular imaging. Issue 6 (9th February 2022)

• Record Type: Journal Article
• Authors: Csupász, Tibor; Lihi, Norbert; Fekete, Zsuzsa; Nagy, Antónia; Botár, Richárd; Forgács, Viktória; Szikra, Dezső; May, Nóra Veronika; Tircsó, Gyula; Kálmán, Ferenc Krisztián
• Is Part Of: Inorganic chemistry frontiers. Volume 9:Issue 6(2022)
• Page Start: 1217
• Page End: 1223
• Publication Date: 2022-02-09
• Subjects: Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d1qi01526e
• Languages: English
• ISSNs: 2052-1553

Abstract

Abstract : Cu(ii ) complexes formed with cross-bridged pentaazamacrocycle ligands exhibit high stability and appropriate inertness, as well as fast complex formation auguring a bright future for this ligand family in radiotheranostic applications. Abstract : 64 Cu is considered to be one of the most promising radioisotopes in radiotheranostics (combining therapeutics with diagnostics) because its positron emission is suitable for PET imaging while the combination of its β − and Auger electrons delivers a therapeutic effect. In this work, we present a thorough coordination chemical characterization of two Cu(ii ) complexes formed from the cross-bridged pentaazamacrocyclic CB-15aneN5 and its bifunctional derivative. The Cu(ii ) chelates possess high thermodynamic stability, fast complexation and moderate inertness under harsh conditions ( t 1/2 = 2.3 h, 5 M HCl, 50 °C). EPR measurements and DFT calculations were carried out for characterizing their structure in solution. Furthermore, the radiolabeling experiments performed with 61 Cu(ii ) confirmed the fast complexation even in the μM concentration range at pH = 6.0. On the basis of these results, the CB-15aneN5 ligand family serves as an excellent platform for Cu(ii ) complexation in radiotheranostics.