盐酸表柔比星长循环磁性脂质体的制备及表征

目的: 制备靶向抗癌药物新剂型-长循环磁性盐酸表柔比星脂质体。方法: 用沉淀法制备纳米磁性Fe3O4粒子,以聚乙二醇单甲醚(mPEG)为修饰剂,采用乙醇注入硫酸铵梯度法制备盐酸表柔比星纳米长循环磁性脂质体;用透射电镜、红外光谱、外加磁场等对制备的脂质体进行表征;采用葡聚糖凝胶柱(Sephadex)紫外法测定脂质体中盐酸表柔比星的包封率,并分别观察水浴孵化时间、卵磷脂与胆固醇的质量比、盐酸表柔比星用量、mPEG用量和不同溶剂等因素对盐酸表柔比星包封率的影响。结果: 制备的纳米磁性Fe₃O₄为近球形颗粒,平均粒径约20 nm,以此磁性材料为磁核所制成的mPEG化盐酸表柔比星磁性脂质体颗粒较圆,平均粒径约50 nm,药物包封率达到57.5％,具有良好的磁响应性、体外稳定性和缓释效果。结论: 此法制备的脂质体包封率高, 重现性好, 简便易行。

Preparation and characterization of mPEG modified magneticlong circulating epirubicin liposomes

Objective: To prepare new dosage form of targeted anti-cancer drug， epirubicin long-circulating magnetic liposomes. Methods: Fe₃O₄magnetic particles were synthesized by the chemical co-precipitation method. Long-circulating epirubicin liposomes were prepared by the ammonium sulphate gradients with ethanol injection, and the methoxy polyethylene glycol(mPEG) was added to modify the membrane property of the liposomes. The characteristics of liposomes were measured by transmission electron microscope (TEM), external magnetic field and FT-IR. The entrapment efficiency of epirubicin was measured by Sephadex-UV method, and the influence of preparation conditions on the encapsulation efficiency of epirubicin was studied to obtain the optimum conditions. Results: The magnetic Fe3O4 nanoparticles were nearly spherical in shape with an average diameter of around 20 nm. The long circulating epirubicin liposomes were nearly round with an average particle of 50 nm. The entrapment efficiency of epirubicin was determined to be 575％. Meanwhile, the experiment results indicated that the long-circulating epirubicin liposomes show good magnetic response, in vitro stability and sustained release property. Conclusion: The method for the preparation of long circulating epirubicin liposomes in this work was easy to be performed with the merits of high encapulation efficiency and reproducibility.