Ganglioside G M ~ and Hydrophilic Polymers Increase Liposome Circulation times by Inhibiting the Association of Blood Proteins

Several agents have been shown to prolong the circulation lifetime of liposomes. These agents, such as ganglioside GM1 or phosphatidylethanolaminederivatives of monomethoxypolyethyleneglycols, provide insight into the mechanism(s) by which liposomes are cleared from the circulation. It is suggested here that the primary mechanism by which these molecules alter the biodistribution of liposomes in vivo involves an inhibition of the association of blood proteins to liposomes, resulting in a diminished rate of clearance of liposomes from the circulation.