Grafting of different glycosides on the surface of liposomes and its effect on the tissue distribution of ¹²⁵I-labelled γ-globulin encapsulated in liposomes

Abstract

Different glycosides were grafted on the surface of liposomes containing ¹²⁵I-labelled γ-globulin by two ways: (1) by using glycolipid and (2) by covalent coupling of p-aminophenyl-D-glycosides to phosphatidylethanolamine liposomes using glutaraldehyde. The distribution of ¹²⁵I-labelled γ-globulin was determined in mouse tissues from 5-60 min after a single injection of these liposomes. The liver uptake of encapsulated ¹²⁵I-labelled γ-globulin was highest from liposomes having galactose and mannose on the surface. Competition experiments and cross-inhibition studies indicate that this uptake are mediated by specific recognition of the surface galactose and mannose residues of liposomes by the receptors present on the plasma membrane of liver cells. Stearylamine-containing liposomes were found to be more efficient in mediating the uptake of ¹²⁵I-labelled γ-globulin by the lung, whereas in the case of spleen, phosphatidylethanolamine liposomes were more efficient. The extent of uptake of ¹²⁵I-labelled γ-globulin from all types of liposome decreases as the amount of given liposomes increases. The uptake of ¹²⁵I-labelled γ-globulin from liposomes containing asialogangliosides depends upon the phospholipid/glycolipid ratio. These experiments clearly demonstrate that enhanced liposome uptake by liver cells could be achieved by grafting galactose and mannose on the liposomal surface.