2. Academic Validation
  3. Amino acid based gallium-68 chelators capable of radiolabeling at neutral pH

Amino acid based gallium-68 chelators capable of radiolabeling at neutral pH

  • Dalton Trans. 2017 Dec 12;46(48):16973-16982. doi: 10.1039/c7dt03398b.
Thomas W Price 1,  Juan Gallo 2,  Vojtěch Kubíček 3,  Zuzana Böhmová 3,  Timothy J Prior 4,  John Greenman 5,  Petr Hermann 3,  Graeme J Stasiuk 1
Affiliations

Affiliations

  • 1 School of Life Sciences, Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK. g.stasiuk@hull.ac.uk and Positron Emission Tomography Research Centre, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
  • 2 Advanced (magnetic) Theranostic Nanostructures Lab, International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal.
  • 3 Department of Inorganic Chemistry, Faculty of Science, Charles University, Hlavova 2030, 12840, Prague 2, Czech Republic.
  • 4 Chemistry, School of Mathematical and Physical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
  • 5 School of Life Sciences, Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK. g.stasiuk@hull.ac.uk.
PMID: 29177295 DOI: 10.1039/c7dt03398b
Abstract

Gallium-68 (68Ga) has been the subject of increasing interest for its potential in the production of radiotracers for diagnosis of diseases. In this work we report the complexation of 68Ga by the amino acid based tripodal chelate H3Dpaa, and two bifunctional derivatives, H3Dpaa.dab and H4Dpaa.ga, under a range of conditions with particular emphasis on the rapid complexation of 68Ga at pH 7.4. 100 μM H3Dpaa achieved a radiochemical yield of 95% at pH 7.4 in 5 minutes at 37 °C. The bifunctional derivatives H4Dpaa.ga and H3Dpaa.dab achieved 94% and 84% radiochemical yields, respectively, under the same conditions. The resulting Ga(iii) complexes show thermodynamic stabilities of log KGaDpaa = 18.53, log KGaDpaa.dab = 22.08, log KGaDpaa.ga = 18.36. Unfortunately, the resulting radiolabelled species do not present sufficient serum stability for in vivo application. Herein we show a flexible synthesis for bifunctional chelators based on Amino acids that rapidly complex 68Ga under physiological conditions.

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