葡萄球菌肠毒素A脂质体的制备及其体内分布试验

Study on Preparation and Tissue Distribution of SEA Liposomes

目的 制备葡萄球菌肠毒素 A(staphylococcal enterotoxin A,SEA)脂质体 ,研究其在体内的分布特性 ,为 SEA脂质体治疗肝癌提供依据。方法 用 1 2 5I标记 SEA,逆相蒸发法制备 SEA脂质体 ,考察其包封率及粒径 ,观察 1 2 5I- SEA及 SEA脂质体静脉注射后不同时间小鼠体内的分布。结果 5批 SEA脂质体样品平均粒径为5 0 5± 34 nm,平均包封率为 44 .4%± 4.8%。SEA脂质体主要分布于肝、脾 ,尤以肝脏中分布最多 ,而在血中清除加快 ,在其他组织中分布显著减少 ,与游离 SEA比较具有显著差异 (P<0 .0 5 )。结论 逆相蒸发法制备 SEA脂质体简单、重复性好 ,可获得较高的包封率和符合肝靶向要求的脂质体 ;SEA脂质体具有一定的肝靶向性 。

Objective To make a study on the preparation and tissue distribution of staphylococcal enterotoxin A (SEA) liposomes and to provide scientific basis for the therapy of liver cancer by using SEA liposomes. Methods SEA liposomes were prepared by reverse-phase evaporation; the diameter and entrapment efficiency (EC) of SEA liposomes were determined. 125I labeled SEA solution and 125I-SEA liposomes were administrated intravenously to mice, respectively. The radioactivity of the organs was determined by γ-counter. Results The mean diameter and EC of SEA liposomes were 505±34nm and 44.1%±4.8%, respectively. SEA liposomes were found mainly distributed in the liver and spleen. SEA liposomes had a higher blood clearance, compared with SEA solution; SEA solution had high-radio-activity in plasma and kidney; there was statistical significance between the two groups (P<0.05). Conclusion The preparation method of SEA liposomes is simple and repeatable. SEA liposomes possess liver-targeting properties and may provide a new application foreground for the treatment of liver cancer.