Technetium-labeling of monoclonal antibodies with functionalized BATOs: 2. TcCl(DMG)3CPITC (CPITC=carboxyphenylisothiocyanate) labeling of B72.3 and NP-4 whole antibodies and NP-4 F(ab')2

Abstract

BATO (boronic acid adduct of technetium dioximes) complexes, TcCl(dioxime)3BR, were prepared in which the boron substituent (R) was the protein-reactive 2-carboxy-4-phenyl isothiocyanate (CPITC). The 99Tc complexes, where the dioxime was either dimethylglyoxime (DMG) or cyclohexanedione dioxime (CDO), were prepared and characterized. The 99mTc complex TcCl(DMG)3CPITC was prepared from a freeze-dried kit and used to label B72.3 (anti-TAG.72) and NP-4 (anti-CEA) whole antibodies, and the NP-4 F(ab')2 fragment. SDS-PAGE electrophoresis indicated that the labeling reagent was strongly bound to antibody. The labeled antibodies displayed high binding to affinity columns and good tumor uptake in GW39 tumor-bearing mice.

6-Hydrazinonicotinamide Derivatives as Bifunctional Coupling Agents for 99mTc-Labeling of Small Biomolecules

“…Various chelators have been used for 99m Tc-labeling of proteins and small BMs. These include N 3 S triamidethiols [65][66][67], N 2 S 2 diamidedithiols [67][68][69][70], N 2 S 2 monoamidemonoaminedithiols [71], N 2 S 2 diaminedithiols [72-77], boronic acid adducts of technetium dioximes [78,79], tetraamines [80], and HYNIC 6-Hydrazinonicotinamide Derivatives as Bifunctional Coupling Agents 133 . However, there is very little comparative data on these chelators with respect to their 99m Tc-labeling efficiency.…”

99mTc Labeling of Highly Potent Small Peptides

“…The use of a polydentate chelate is also beneficial for minimizing isomerism. BATOs (boronic acid adducts of technetium dioximes) (84,85) and DTPA (86) have been used as BFCAs for the 99m Tc labeling of antibodies.…”

Phenylboronic Acid−Salicylhydroxamic Acid Bioconjugates. 1. A Novel Boronic Acid Complex for Protein Immobilization

“…Similarly, a PBAalkaline phosphatase conjugate utilized in an enzymelinked assay for glycated hemoglobin failed to detect the presence of glycoprotein. Radioactive technetium dioxime complexes have been conjugated to monoclonal antibodies with either 3-isothiocyanatophenylboronic acid (21) or 3-carboxy-5-isothiocyanatophenylboronic acid (22) and have proven useful for medical imaging.…”