Labeling of monoclonal antibodies with a Ga-phenolic aminocarboxylic acid chelate.

Autor: Schuhmacher, Jochen, Matys, Ronald, Hauser, Harald, Maier-Borst, Wolfgang, Matzku, Siegfried
Zdroj: European Journal of Nuclear Medicine; Nov1986, Vol. 12 Issue 8, p397-404, 8p
Abstrakt: As a chelating agent for labeling antibodies (Abs) with metallic radionuclides, a propionic acid substituted ethylenediamine N,N′-di-[(o-hydroxyphenyl) acetic acid] (P-EDDHA), which tighly complexes Ga, was synthesized. The Ga-P-EDDHA chelate was coupled in aqueous solution to IgG at a molar ratio of 1:1 via carbodiimide. The average coupling yield was 15%. A specific activity of 4 mCi/mg IgG could be obtained with commercially supplied Ga. In vitro stability was evaluated in human serum at 37° C and showed a half-life of about 120 h for the release of Ga from the labeled Ab during the initial phase of incubation. This in vitro halflife is similar to that measured for In-DTPA labeled Abs. Because of the high stability of the Ga-P-EDDHA chelate, the in vivo formation of radioactive labeled transferrin by transchelation, as described for In-DTPA labeled Abs, should, however, be reduced by this labeling technique. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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