In vivo behavior of liposomes modified with a novel galactosyllipid derivative

We studied the in vivo behavior of galactosyllipid-modified liposomes for targeting the asialoglycoprotein receptor present on the surface of liver parenchymal cells. We examined the effects of the lipid composition of liposomes on the in vivo behavior of galactosyllipid-modified liposomes, and found good accumulation in the liver of liposomes of a high cholesterol content and liposomes made of lipids of a high gel-liquid crystalline phase transition temperature. The amount of modification with the galactosyllipid derivative required for effective targeting to the liver was found to be more than 5% of the total lipids. The concentration of galactosyllipid-modified liposomes was lower than that of control liposomes in all the organs except for the liver, showing high selectivity of galactosyllipid-modified liposomes for the liver. Hepatic accumulation of liposomes was inhibited by preinjection of asialofetuin. This result suggests that hepatic accumulation of ¿8-(2-hexadecyloctadecanoylamido)-3,6-dioxaoctyl¿-beta-D-gal actoside (Gal-t-psa) liposome was involved with the asialoglycoprotein receptor in the liver. Therefore, it was concluded that our neogalactolipid-modified liposomes are useful for selective delivery to the liver.