阳离子脂质材料和聚乙二醇对脂质体细胞转染率及膜流动性的影响阳离子脂质材料和聚乙二醇对脂质体细胞转染率及膜流动性的影响

目的制备包封荧光素钠（FS）的脂质体，考察阳离子脂质材料（DC-chol）和聚乙二醇（PEG）对脂质体包封率、细胞转染率及膜流动性的影响。方法以FS作为模型物质，制备并分离脂质体，测定脂质体包封率；通过观察荧光光谱的变化考察FS与脂质体膜之间的相互作用；以HepG₂ 2.2.15为细胞模型观察脂质体对FS细胞转染率的影响；通过荧光偏振技术考察阳离子脂质材料和PEG对脂质体膜流动性的影响。结果阳离子脂质材料和PEG能提高脂质体包封率（0.64％～86.57％）、细胞转染率（2.18％～48.46％）及脂质体膜流动性，PEG分子质量的增大有利于包封率、转染率的提高，并增加脂质体膜的流动性。结论在脂质体处方中加入阳离子脂质材料和高分子量的PEG有利于提高包封率、细胞转染率及增加脂质体膜的流动性。

Cationic lipid and polyethylene glycol enhance liposomes-mediated cell transfection and increase the fluidity of liposomes membranes

AIM: To prepare fluorescein sodium (FS) cationic liposomes and investigate the influence of cationic lipid (DC-chol) and polyethylene glycol (PEG) with different molecule weight (MW) on cationic liposome incorporation efficiency, cellular delivery and fluidity of liposome membrane. METHODS: Using FS as a model material for encapsulation, the liposomes were prepared and separated (by sephadex G-50 1 cm x 20 cm column), and the liposome incorporation efficiencies was measured. The interaction between the FS and cationic liposomes was investigated by measuring the change of fluorescent spectrum. The cellular uptake of different liposome forms by choosing HepG2 2.2.15 as an in vitro cell culture assay model, and the influence of PEG on the fluidity of liposome membrane with the technique of fluorescence polarization were investigated. RESULTS: Cationic lipid and different PEGs showed great effects on increasing liposome incorporation efficiency (from 0.64% to 86.57%), cellular uptake (from 2.18% to 48.46%) and fluidity of liposome membrane. The effect of PEG was MW dependent, and with the increase of MW, the incorporation efficiency and transfection was improved, and the fluidity of liposome membrane increased. CONCLUSION: Addition of cationic lipid and high MW PEG into cationic liposomes can enhance the cellular delivery and fluidity of cationic liposomes. Also, they can improve the incorporation efficiency of cationic liposomes.