Abstract |
Monoclonal antibodies (MAb) and their F(ab')2 fragments to human colorectal carcinoma (CRC) and human melanoma-associated antigens were conjugated to diethylenetriaminepentaacetic acid ( DTPA) via an acylation reaction using cyclic DTPA dianhydride. Relative immunoreactivity of the F(ab')2 fragments was as high as 70% when an average of only 0.7 DTPA molecules was conjugated per fragment, decreasing rapidly to less than 5% when 9.0 DTPA molecules were conjugated. The 111In-labeled whole MAb in mice bearing human tumor xenografts showed higher concentrations in tumor, liver, kidney, and spleen 7 days after injection of MAb when compared with the same MAb labeled with 131I. F(ab')2 labeled with 111In showed a marked persistence in the tumor-bearing mice with higher concentrations in all organs except blood, when compared with 131I-labeled F(ab')2. Radioactivity was particularly high in the kidneys. Although images of human tumor xenografts were easily visualized using 131I-labeled F(ab')2 3 days after injection, it was difficult to visualize tumor grafts with 111In-labeled F(ab')2 due to persistently high renal, liver, and background activity. Increased catabolism of the 131I-labeled MAb may be the cause of the difference; but antibodies with high immunological activity are a necessity for in vivo imaging studies before firm conclusions can be drawn.
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Authors | J Powe, K Y Pak, C H Paik, Z Steplewski, M A Ebbert, D Herlyn, C Ernst, A Alavi, W C Eckelman, R C Reba |
Journal | Cancer drug delivery
(Cancer Drug Deliv)
Vol. 1
Issue 2
Pg. 125-35
( 1984)
ISSN: 0732-9482 [Print] United States |
PMID | 6544629
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Antibodies, Monoclonal
- Immunoglobulin Fab Fragments
- Radioisotopes
- Indium
- cyclic DTPA anhydride
- Pentetic Acid
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Topics |
- Animals
- Antibodies, Monoclonal
- Humans
- Immunoglobulin Fab Fragments
- Indium
- Mice
- Mice, Inbred BALB C
- Molecular Weight
- Neoplasm Transplantation
- Neoplasms, Experimental
(diagnostic imaging)
- Pentetic Acid
(analogs & derivatives)
- Radioisotopes
- Radionuclide Imaging
- Transplantation, Heterologous
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