Utility of liposomes coated with polysaccharide bearing 1-amino-lactose as targeting chemotherapy for AH66 hepatoma cells

The cell recognition element is very important for drug delivery systems. We synthesized cholesteryl pullulan (CHP) bearing 1-aminolactose (1-AL) and introduced a saccharide, cholesteryl pullulan bearing 1-aminolactose (1-AL/CHP), to an outer layer of the conventional liposome as a cell recognition element. Lectin recognized the beta-galactose by aggregation of 1-AL/CHP coated liposome (1-AL/CHP liposome). The uptake of this liposome to AH66 rat hepatoma cells was greater than in liposomes without 1-aminolactose in vitro. Furthermore, 1-AL/CHP liposomal adriamycin showed a stronger antitumor effect in comparison with other types of liposomal adriamycin in vitro. When in vivo tumor-targeting efficacy was investigated in AH66 tumor transplanted mice using 3H-liposome, the tumor/serum radioactivity ratio in mice injected with 1-AL/CHP liposome was higher than that of mice injected with other liposomes. These observations suggest that 1-AL is effective as a cell recognition element. As a result, 1-AL/CHP liposome is considered to be a good carrier of anticancer drugs for the active targeting of tumor cells.