LIPOSOME-ASSOCIATED RETINOIDS - PRODUCTION, CHARACTERIZATION AND ANTIPROLIFERATIVE ACTIVITY ON NEOPLASTIC-CELLS

The administration of retinoids has been demonstrated to be of potential utility in the therapy of a wide spectrum of neoplastic pathologies. This is due to the strong antiproliferative effect on neoplastic cells and to the ability to induce differentiation in a large variety of cell lines. In the present paper we describe the preparation and characterization of liposome-associated natural and synthetic retinoids. Liposomes were prepared by reverse phase evaporation technique followed by extrusion through polycarbonate filters. Analysis of the in vitro antiproliferative activity on cultured human leukemic K562 cells demonstrated that liposome-associated retinoids are up to 200 times more active than the corresponding retinoids administered in the free form. Based on these promising results, a proposal is made for in vivo administration of these antiproliferative agents by using liposomes as a drug delivery system.