[Use of liposomes for drug targeting]

Liposomes are considered to be one of the perspective carriers for drug targeting in the organism. The drug preparation can be incorporated into the inner water space of liposomes and the molecule capable of recognition and binding to the target-zone should be bound to the outer surface of the membrane. Thus, the elaboration of effective methods for binding affinity proteins with liposome surface is of particular importance. Two principal schemes of such a binding are worked out: introduction of reactive groups into the liposome membrane with subsequent chemical protein binding or preliminary modification of protein by the hydrophobic reagent with its subsequent noncovalent incorporation into the liposome. In the first case liposomes can contain reactive aminophospholipids, dithiopropionate-phospholipids and fatty acid derivatives of polysaccharides activated by oxidation. Enzymes and antibodies are bound to liposomes, preserving the specific activity, with the binding yield up to 40% and the bound protein quantity of about 2 X 10(-4) mol per mol of lipid. In the second case proteins modified by fatty acid derivatives or by phosphatydyl inositol are incorporated into liposomes in quantity of about 2 X 10(-3) mol per mol of lipid and with binding yield of about 50%.