Open AccessSynthesis and biological investigations of a ZnPc-antiCEA bioconjugate for imaging of colorectal cancer
Author(s) -
Inder Sehgal,
Hairong Li,
Benson G. Ongarora,
Daniel Devillier,
M. Graça H. Vicente
Publication year - 2013
Publication title -
journal of porphyrins and phthalocyanines
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.322
H-Index - 64
eISSN - 1099-1409
pISSN - 1088-4246
DOI - 10.1142/s108842461250143x
Subject(s) - bioconjugation , chemistry , carcinoembryonic antigen , monoclonal antibody , colorectal cancer , fluorescence , antibody , conjugated system , in vitro , conjugate , cancer research , microbiology and biotechnology , antigen , cancer , combinatorial chemistry , biochemistry , immunology , medicine , mathematical analysis , physics , mathematics , organic chemistry , quantum mechanics , biology , polymer
Two zinc(II) phthalocyanines (ZnPcs) were conjugated with a monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA), using an in situ activated carboxylic acid on the ZnPcs. The bioconjugate with the highest ZnPc/MAb ratio of 3 was investigated in vitro for its ability to target and fluorescently label human colorectal HT-29 cells. The ZnPc-CEA MAb 2 was observed to efficiently target HT-29 cells, about 37 times more than unconjugated ZnPc. Furthermore, in the presence of a 4-fold excess of unlabelled anti-CEA antibody, the fluorescence signal of 2 was reduced by ~90% showing that the targeting is CEA-mediated. These studies further confirm the high specificity of Pc-antibody conjugates for antigens over-expressed on tumor cells and warrant further investigations of these immunoconjugates and their derivatives for imaging of colorectal cancer.