摘要
Liposomes were prepared with natural soybean phospholipids by extrusion method after rotating-film evaporating technique. Transmission electron micrography was used to detect the appearances of the prepared liposomes, and the liposome diameter was also measured. The prepared liposomes were sphere in shape with the mean diameter of 217 nm and span of 0.838. The phospholipid bilayer structure, suitable for entrapping various effector molecules, could be seen clearly under transmission electron microscopy. The bile salts of sodium cholate and sodium deoxycholate were used as the surfactants to investigate their interaction with liposomes. The turbidities for the mixture of bile salts and liposomes were evaluated by the visible spectrometry method at the wavelength of 500 nm. And the diameter changes of liposomes were also tested to examine the effect of bile salts on liposomes. At the beginning, the diameters and turbidities of liposomes increased a little as the result of mixed micelles formation during the different stages for the structure changes of surfactant-liposomes micelles. The further added bile salts decreased the diameters and turbidities of liposomes. The liposome suspension underwent several rearrangements before small mixed micelles formed. And the diameter of liposomes changed regularly. The interaction of bile salts and liposomes is important for the further study of the behaviors of liposomes in vivo. The drug loaded and release properties of liposomes can also be well reflected by the interaction of liposomes and surfactants.
采用旋转薄膜蒸发法结合挤压过滤工艺制备大豆磷脂脂质体,所制得脂质体的平均粒径为217 nm,跨距0.838,负染色脂质体经透射电镜观察,呈明显的双层膜圆球型结构。以胆酸钠盐和脱氧胆酸钠盐研究其与脂质体之间的相互作用,将500 nm波长处的可见光吸收值评价胆盐-脂质体混悬液的浊度,测定脂质体的粒径变化情况。在胆酸盐加入的初期,由于胆酸盐和脂质体形成混合胶团,致使脂质体的粒径和浊度值稍有增加,进一步加入的胆酸盐使脂质体的粒径和浊度值下降。胆盐和脂质体间的相互作用经历了数个重排现象,使脂质体的粒径发生规律性的变化,这与脂质体的体内稳定性密切相关,也可反映脂质体的载药和释药特性。
