A rigidified AAZTA-like ligand as efficient chelator for 68Ga 
radiopharmaceuticals

Vágner, A; D'Alessandria, C; Gambino, G; Schwaiger, M; Aime, S; Maiocchi, A; Tóth, I; Baranyai, Z; Tei, L

doi:10.1002/slct.201500051

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

A rigidified AAZTA-like ligand as efficient chelator for 68Ga radiopharmaceuticals

MPS-Authors

There are no MPG-Authors in the publication available

External Resource

Link
(Any fulltext)

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Vágner, A., D'Alessandria, C., Gambino, G., Schwaiger, M., Aime, S., Maiocchi, A., et al. (2016). A rigidified AAZTA-like ligand as efficient chelator for 68Ga radiopharmaceuticals. ChemistrySelect, 1(2), 163-171. doi:10.1002/slct.201500051.

Cite as: https://hdl.handle.net/21.11116/0000-0000-7A16-F

Abstract

The new cyclohexane-fused CyAAZTA ligand was synthesized to increase the structural rigidity of the heptadentate chelator AAZTA with the aim of improving the overall stability of its GaIII complex. The stability constant of Ga(CyAAZTA)−, determined both by pH-potentiometry (logKGaL=21.39) and by 71Ga NMR (logKGaL=21.92), was found similar to that of GaAAZTA (logKGaL=22.18). The kinetic inertness of Ga(CyAAZTA)− was investigated by following its transmetallation and ligand exchange reactions with Cu2+ and human serum transferrin, respectively. The formation of a hydroxido-complex near pH 7 decreases the half-life (t1/2) of the dissociation reactions for Ga(CyAAZTA)− compared to Ga(AAZTA)− (8.5 h vs 21 h, pH 7.4). However, at pH < 7 the t1/2 of Ga(CyAAZTA)− is much longer (234 h at pH 6). Finally, CyAAZTA was successfully radiolabelled with 68Ga in acetate buffer at pH 3.8, in 15 minutes at room temperature at [CyAAZTA]=10 μM, with a labelling yield higher than 80 . A 1 μM solution of CyAAZTA was successfully labelled (L.Y.: 97.4 ) in 5 minutes at 90 °C. Stability tests in human serum and in the presence of 50 mM DTPA showed no significant decomposition of 68GaCyAAZTA over 90 minutes.