载基因纳米脂质体的制备及有关性质的初步研究

目的用去污剂透析法制备载基因脂质体并考察其性质。方法以大豆磷脂和双十八烷基二甲基溴化铵为脂质材料,以Myrj53为表面修饰材料制备载基因纳米脂质体,用透射电子显微镜观察脂质体的形态,用纳米粒度及电位分析仪测定脂质体的粒径大小、多分散指数及zeta电位,并考察载基因纳米脂质体对DNA的包封率及体外保护DNA抵抗核酸酶降解的性质。结果制得的脂质体形态较为圆整,平均粒径为(72.73±7.14)nm(n=3),多分散指数为0.288±0.093(n=3),zeta电位为(-23.77±3.51)mV(n=3),包封率为88.13%±4.41%(n=3),DNase体外降解实验和凝胶电泳分析表明脂质体对质粒DNA有较强的保护作用。结论去污剂透析法是制备载基因纳米脂质体有效可行的方法。

Study on the Preparation of Plasmid DNA-containing Liposomes and Their Properties

OBJECTIVE: To prepare plasmid DNA-containing liposomes using detergent removal method and investigate the properties of liposomes. METHODS: Using soybean phospholipid and DDAB as lipid materials and Myrj53 as surface modified material, we prepared liposomes by means of detergent removal technique. The shape, size and zeta potential of the liposomes were characterized by TEM and laser particle size analyzer, respectively. The encapsulation efficiency was also investigated. The ability of liposomes to protect the plasmid DNA from degradation was investigated through incubation with DNase I for different time. RESULTS: The liposomes were relatively and regularly spherical in shape and had an average size of 72.73 +/- 7.14 (n = 3) nm with the polydispersity index of 0.288+/-0.093 (n = 3). The zeta potential of the liposomes was -23.77+/- 3.51 (n = 3) mV. The encapsulation efficiency of DNA reached 88.13% +/- 4.41% (n = 3). Liposomes could provide DNA with enough protection from degradation by DNase I . CONCLUSION: Detergent removal method is effective and practicable for preparing small-sized plasmid DNA-containing liposomes.