Liposome elimination by non-phagocytic cells of the liver

In this contribution we summarize our observations over a period of nearly two decennia on the role of hepatocytes in the hepatic clearance of intrave nously administered liposomes. We demonstrate that, although size is an imp ortant parameter, it is not decisive in determining access of liposomes to the hepatocytes. Also lipid composition is an important parameter, includin g charge, rigidity and headgroup composition. The role of the fenestrated s inusoidal endothelial cells in accessibility is discussed as well as the in volvement of opsonizing plasma proteins such as apolipoprotein E. Our obser vations led us to hypothesize at least four different mechanisms of interac tion of liposomes with hepatocytes.