Erythrocyte entrapment of daunomycin by amphotericin B without hemolysis.

Amphotericin B is a polyene that binds to sterols and perforates cell membranes. An antileukemic drug such as daunomycin added exogenously is impermeable to the red cell membrane. However, when the cells are incubated with a low concentration of amphotericin B, daunomycin is entrapped in the red cells without hemolysis or alteration in the chemical parameter of the erythrocytes. The erythrocyte has been used as a carrier vehicle to enhance the cytotoxic activity of daunomycin against L1210 leukemic cells. In comparison to control preparations, the greatest increase in survival was obtained in vivo when the erythrocytes with entrapped daunomycin were given to C57BL X DBA/2 F1 mice bearing L1210 cells.