Covalent binding of antibodies to liposomes using a novel lipid derivative

N-[3−(2−Pyridyldithio) propionyl] stearylamine (PDP-SA) was synthesized from a reaction between stearylamine and the heterobifunctional reagent N-succinimidyl−3−(2−pyridyldithio) propionate. Use of this PDP-SA to covalently couple antibodies to liposomes was investigated. The binding efficiency was found to be 24–32%. The antibodies bound to liposomes were shown to retain the specific antibody activity. This new procedure of coupling antibodies to lipsosomes could be an efficient means to deliver drugs to selected target organs, especially in cancer chemotherapy.