Preparation, biodistribution, and dosimetry of 188Re-labeled MoAb ior cea1 and its F(ab')2 fragments by avidin-biotin strategy.
The biotinylated monoclonal antibody (MoAb) ior cea1 and its F(ab')2 fragments were labeled with Re-188 by combination of avidin-biotin strategy. 188Re-MoAb, 188Re-MoAb-biotin, 188Re-F(ab')2, and 188Re-F(ab')2-biotin preparations were produced for these studies with specific activities of 1.30+/-0.18 GBq/mg and from instant freeze-dried kit formulations using ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand. There were no significant differences (p > 0.05) between the biodistribution in mice of biotinylated and unbiotinylated 188Re-labeled immunoconjugates. When avidin was injected as a chase after injection of 188Re-MoAb-biotin or 188Re-F(ab')2-biotin, the blood radioactivity level decreased approximately 75% (cumulated activity) and the effective dose decreased almost 25% with respect to that of the radioimmunoconjugates in which the chase effect was not used. Our results suggest that 188Re-labeled biotinylated MoAb ior ceal and its F(ab')2 fragments prepared by this method are stable complexes in vivo.
Ferro-Flores
G
G
Departamento de Materiales Radioactivos, Instituto Nacional de Investigaciones Nucleares, Salazar, México. gff@nuclear.inin.mx
Pimentel-González
G
G
González-Zavala
M A
MA
Arteaga de Murphy
C
C
Meléndez-Alafort
L
L
Tendilla
J I
JI
Croft
B Y
BY
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D001360:Avidin; D001710:Biotin; D002272:Carcinoembryonic Antigen / Q000276:immunology*; D012968:Etidronic Acid; D005260:Female; D018796:Immunoconjugates / Q000378:metabolism*; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D012211:Rhenium / Q000378:metabolism*; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D018796:Immunoconjugates; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D008024:Ligands; D001360:Avidin; D001710:Biotin; D012211:Rhenium; D012968:Etidronic Acid