ABSTRACT

Two methods are used in the laboratory for the preparation of antibody-targeted liposomes. Both methods depend on the generation of a phosphatidylethanolamine (PE)-antibody or PE-F(ab’)2 complex. In the first method, the PE-F(ab’)2 conjugate is associated with preformed small unilamcllar vesicles (SUV). The second method of the preparation of targeted liposomes involves the use of a detergent. The preparation of SUV involves prolonged sonication. SUV have been shown to remain in the circulation for a longer time than large multilamellar vesicles and are more likely than any other liposomal preparations to cross anatomical barriers. The prolonged ultrasonic irradiation necessary to produce SUV is in compatible with certain substances one may wish to entrap. In the procedure the liposomes are formed as already described for the entrapment of meth otrexate except that DT-A is entrapped instead of the drug. Liposomes are formed upon the removal of the detergent by gel filtration, as described by H. G. Enoch and P. Strittmatter.