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

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