Design of immuno-enzymosomes with maximum enzyme targeting capability: effect of the enzyme density on the enzyme targeting capability and cell binding propertiesFonseca, MJ., Haisma, HJ., Klaasen, S., Vingerhoeds, MH. & Storm, G., 15-Jul-1999, In : Biochimica et Biophysica Acta-Biomembranes. 1419, 2, p. 272-282 11 p.
Research output: Contribution to journal › Article › Academic › peer-review
Immuno-enzymosomes have been proposed for the targeting of enzymes to cancer cells to achieve site specific activation of anticancer prodrugs. Previously, we reported that the enzyme beta-glucuronidase (GUS), capable of activating anthracycline-glucuronide prodrugs, can be coupled to the surface of inmunoliposomes directed against human ovarian cancer cells (OVCAR-3). This study aimed at the design of an immuno-enzymosome formulation with maximum enzyme targeting capability. By purification of the commercially available enzyme beta-glucuronidase (GUS), a 2-fold increase in the enzyme specific activity and a 4-fold increase in the enzymatic activity of immuno-enzymosomes was achieved. As a result, upon incubation with human ovarian cancer cells (OVCAR3), cell-associated enzymatic activity increased correspondingly. The optimized immuno-enzymosomes were shown to bind to the target cells in a specific fashion. Above a GUS/Fab' molar ratio of 0.5, impairment of the target cell binding ability of the immuno-enzymosomes was observed. This was likely due to a steric hindrance effect mediated by the presence of large amounts of bulky GUS molecules on the liposome surface. Nevertheless, increasing the GUS density on the surface of the immuno-enzymosomes to levels by far exceeding the GUS/Fab' molar ratio of 0.5, yielded a considerably Improved enzyme targeting capability. (C) 1999 Elsevier Science B.V. All rights reserved.
|Number of pages||11|
|Journal||Biochimica et Biophysica Acta-Biomembranes|
|Publication status||Published - 15-Jul-1999|
- liposome, antibody-directed enzyme prodrug therapy, ADEPT, enzyme targeting, cell binding, SITE-SPECIFIC ACTIVATION, HUMAN OVARIAN-CARCINOMA, MONOCLONAL-ANTIBODY, ALKALINE-PHOSPHATASE, ETOPOSIDE PHOSPHATE, BETA-GLUCURONIDASE, PRODRUG THERAPY, CANCER-THERAPY, IMMUNOLIPOSOMES, LIPOSOMES