Prolonged Retention of Doxorubicin in Tumor Cells by Encapsulation of gamma-Cyclodextrin Complex in Pegylated Liposomes

摘要

For further increase of retention of doxorubicin (DOX) in tumor cells,we prepared the pegylated liposomes entrapping the complex of DOX with gamma-cyclodextrin (gamma-CyD) (complex-in-liposome),and then examined the physicochemical properties and the in vitro cellular uptake/release,compared with those of pegylated liposomes entrapping DOX alone (DOX-in-liposome).The particle sizes of these liposomes were almost comparable,and the entrapment ratios of both DOX and gamma-CyD in liposomes were more than 90%.The release of DOX from liposomes in the fetal calf serum (FCS) was significantly inhibited by entrapment of gamma-CyD in the liposomes.The cellular uptake of DOX into Colon-26 cells,a mouse rectal carcinoma cell line,after incubation with these liposomes was almost equivalent.However,the cellular release of DOX from cells in the complex-in-liposome system was markedly slower than that in the DOX-in-liposome system.These results suggest the potential use of liposomes containing the DOX/gamma-CyD complex for high retention of DOX in tumor cells.