POTENTIATION OF RICIN-A IMMUNOTOXIN BY MONOCLONAL-ANTIBODY TARGETED MONENSIN CONTAINING SMALL UNILAMELLAR VESICLES

The carboxylic ionophore monensin could be successfully entrapped in s mall unilamellar vesicles made by the extruder method. Monensin liposo mes of size range 100-150 nm were more potent in potentiating ricin A immunotoxin activity in vitro as compared to monensin liposomes of dia meter 500 nm or more.-These liposomes were further successfully linked to tumor specific monoclonal antibodies with full retention of immuno reactivity. Monoclonal antibody targeted monensin liposomes were 100 t imes more potent than monensin liposomes in potentiating the activity of ricin A immunotoxins against various tumor cell lines in vitro.