Preparation of Chitosan-Coated Liposome Containing Anticancer Drug and DNA Complex

摘要

To enhance therapeutic efficacy of anticancer treatment, combination therapies which administrate both chemotherapeutic agent and therapeutic DNA have been developed. Negatively charged liposomes containing chemotherapeutic agent were prepared and surface of the liposomes were modified with a polycationic polymer, chitosan. The green fluorescence protein expressing plasmid DNA (pcDNA-GFP) was conjugated with the modified liposomes and the transfection efficiency was inspected. The particle size and zeta potential of the liposomes containing chemotherapeutic agent were 120 nm and 0 mV, respectively. Incorporation of DPPA into liposomes resulted increase of the particle size up to 170 nm and change of zeta potential to -50 mV. Loading efficiency of chemotherapeutic agent, doxorubicin, in the liposomes was not dependent on the concentration of DPPA. After surface modification of liposomes with chitosan, the particle size increased to 220 nm and the surface charge was positive with a zeta potential of +30 mV. The optimal neutralization ratio of DNA/liposome complex by gel retardation assay and measuring fluorescence intensity by EtBr was 0.5-1.0 (v/v). The transfection of plasmid DNA complex into human cervix adenocarcinoma cells (HeLa) was monitored by fluorescence microscopy. The transfection efficiency of plasmid DNA mediated by the chitosan-modified liposome was better compared to the naked DNA.