Abstract
We have developed the coating of liposomes with a cell specific polysaccharide. Carbohydrates play a very important role in biological recognition system. In this study, galactosamin(1), 1-amino-galactose(2), 1-amino-mannose(3), 1-amino-glu-cose(4)was selected and partly replaced to be an effective sensory device on naturally occurring polysaccharide such as pullulan. The polysaccharide-coated liposomes become significantly stable both physicochemically and biochemically and also cell recognizable. Recognizabilities of the poly-saccharide-coated liposomes were confirmed by specific lectin-induced aggregation, cell-liposome interaction, and tissue distribution. Liposomes coated with pullulan derivatives(1-3)were effectively endocytosed by human neutrophils and monocytes, while liposomes coated with pullulan derivative(4) inhibited the endocytosis. When galactosamin-modified pullulan-coated liposome was intravenously administrated into mice, liver uptake increased compared with the simple pullulan-coated liposome. These findings suggest that terminal sugars of modified polysaccharides act as a potentially valuable sensory device of drug delivery system.
