SYNTHESES OF NOVEL GALACTOSYL LIGANDS FOR LIPOSOMES AND THE INFLUENCEOF THE SPACER ON ACCUMULATION IN THE RAT-LIVER

We modified the surface of liposomes with galactosyl ligands, At first we determined whether or not the galactosyl moiety was exposed on the liposomes, We then investigated the effect of the ligands on the hepa tic accumulation of liposomes in rats, We introduced an oligoethylene glycol moiety as a spacer. Among the various ligands tested, those wit h a tri- or tetraethylene glycol moiety as a spacer caused the greates t accumulation of liposomes in the liver, Liposomes bearing ligands wi th a tri- or tetraethylene glycol moiety as a spacer, were aggregated by Ricinus communis agglutinin. On the other hand, those modified with ligands with a mono- or diethylene glycol spacer did not clearly aggl utinate, These results show the importance of a spacer between the hom ing device and the ligand anchor.