Antibody coating of liposomes with 1-ethyl-3-(3-dimethyl-aminopropyl)carbodiimide and the effect on target specificity.

Liposome surfaces were modified with normal rabbit IgG or rabbit anti-sheep erythrocyte IgG by adsorption or by coupling with a water soluble cross-linking reagent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI). Modification with normal IgG reduced the non-specific binding of the liposomes to erythrocytes. The immunological binding capacity of the immune IgG on liposomes was better for the chemically coupled preparation than for the adsorbed one. Complement dependent cytolytic activity of the immune IgG towards target erythrocytes was diminished as a consequence of liposome binding by either method, but to a lesser extent in the coupling method. Antibody coating by EDCI thus provides liposomes which can bind effectively to antigenic target cells.