Coating of liposomes with subunits of monoclonal IgM antibody and targeting of the liposomes.

SH-bearing subunits of IgM antibody were coupled through the Fc portion to sonicated liposomes consisting of N-(m-maleimidobenzoyl)dipalmitoylphosphatidylethanolamine, dipalmitoylphosphatidylcholine and cholesterol. Liposomes coated with subunits of monoclonal IgM antibody against a mouse mammary tumor-associated antigen selectively bound to the antigenic target cells. Assays of the liposomes for complement dependent cytotoxicity and spleen cell binding revealed inactivation of the liposome-coupled antibodies in both assays.