Is DTPA a good competing chelating agent for Th(IV) in human serum and suitable in targeted alpha therapy?

Autor: Alfred Morgenstern, Gilles Montavon, Andrea Sabatié-Gogova, Alicia Le Du
Rok vydání: 2012
Předmět:
Zdroj: Journal of Inorganic Biochemistry. 109:82-89
ISSN: 0162-0134
DOI: 10.1016/j.jinorgbio.2011.12.011
Popis: The interaction between thorium and human serum components was studied using difference ultraviolet spectroscopy (DUS), ultrafiltration and high-pressure-anion exchange chromatography (HPAEC) with external inductively conducted plasma mass spectrometry (ICP-MS) analysis. Experimental data are compared with modelling results based on the law of mass action. Human serum transferrin (HSTF) interacts strongly with Th(IV), forming a ternary complex including two synergistic carbonate anions. This complex governs Th(IV) speciation under blood serum conditions. Considering the generally used Langmuir-type model, values of 10(33.5) and 10(32.5) were obtained for strong and weak sites, respectively. We showed that trace amounts of diethylene triamine pentaacetic acid (DTPA) cannot complex Th(IV) in the blood serum at equilibrium. Unexpectedly this effect is not related to the competition with HSTF but is due to the strong competition with major divalent metal ions for DTPA. However, Th-DTPA complex was shown to be stable for a few hours when it is formed before addition in the biological medium; this is related to the high kinetic stability of the complex. This makes DTPA a potential chelating agent for synthesis of (226)Th-labelled biomolecules for application in targeted alpha therapy.
Databáze: OpenAIRE
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