Send to

Choose Destination
Pharm Res. 1998 Jul;15(7):1031-7.

Lectin-mediated drug targeting: preparation, binding characteristics, and antiproliferative activity of wheat germ agglutinin conjugated doxorubicin on Caco-2 cells.

Author information

Institute of Pharmaceutical Technology, the University of Vienna, Austria.



To investigate the usefulness of wheat germ agglutinin as a targeting carrier protein for an acid-labile chemotherapeutic prodrug directed against colon carcinoma cells in vitro.


Cis-aconityl-linked doxorubicin-wheat germ agglutinin was prepared by a two step procedure and the conjugate-binding capacity of target- and non-target cells was assayed by flow cytometry. The antiproliferative activity of the prodrug on Caco-2 and MOLT-4 cells was determined by the XTT- and BrdU-test and compared with that of the parent drug and the lectin alone.


At pH 4.0, about 50% of the conjugated doxorubicin were released within 24 h from the water soluble prodrug exhibiting a conjugation number of 24 (mol doxorubicin/mol WGA). The prodrug-binding capacity of colon carcinoma cells exceeded that of human colonocytes and lymphoblastic MOLT-4 cells 4.5-fold. Additionally, the antiproliferative effect of the conjugate on Caco-2 cells was 39% as opposed to 5% in case of MOLT-4 cells. As the unmodified carrier protein inhibited or stimulated Caco-2 cell growth in a concentration-dependent manner, the cytostatic activity of the conjugate was determined at WGA concentrations without an effect on cell-proliferation. Considering 50% release of conjugated drug at the most, the prodrug yielded 160% of the cytostatic activity of free doxorubicin.


WGA-prodrug targeting offers new perspectives for site-specific, cytoinvading drug delivery in colon cancer chemotherapy.

[Indexed for MEDLINE]

Supplemental Content

Loading ...
Support Center