磁性脂质体的制备及其在小鼠体内的分布磁性脂质体的制备及其在小鼠体内的分布

目的制备磁性脂质体并考察其理化性质及在小鼠体内的自然分布和诱导分布,从而探讨该系统在小鼠体内分布的规律和磁响应性。 方法采用反相蒸发法制备磁性脂质体,以邻二氮菲染色法测定脂质体中铁磁性物质的包载量,按中国药典之规定对其理化性质进行测定,采用同位素示踪的方法研究其在小鼠体内的分布情况。 结果 磁性脂质体平均粒径为602.5 nm,每毫升脂质体悬液可包载88.1 μg Fe₃O₄。自然状态下经尾静脉给药后磁性脂质体主要被脾脏摄取;而在磁场诱导条件下脾脏中摄取量减少,左右侧肝叶、左右侧肾脏中制剂分布产生明显的差异。结论采用反相蒸发法可以制得稳定、粒径均一、铁磁性物质包载量较高的磁性脂质体,同时其在小鼠体内能够对外磁场产生响应而定向分布。

Preparation of magnetoliposomes and its in vivo behavior on ICR mice

AIM: To prepare magnetoliposome (MLP) containing dextran-encapsulated magnetite (Fe3O4), and to examine its physicochemical properties and its in vivo behavior on ICR mice. METHODS: Reverse phase evaporation method was used to formulate MLP and the Fe2+ concentration was measured by o-phenanthroline method. Then the basic properties of MLP and in vivo distribution were studied with the aid of 3H isotope as biomarker. RESULTS: The mean diameter of MLP was 602.5 nm and the final concentration of encapsulated Fe3O4 was 88.1 mg x L(-1). Under natural conditions most of the MLP was taken up by spleen after the administration via tail vain, but its uptake was reduced under the magnetic field. There was a great difference in vivo distribution between the left and right lobes of the liver and the left and right kidneys in magnetic fields. CONCLUSION: Reverse phase evaporation method was utilized to prepare magnetoliposomes. The formulation was stable and encapsulated high amount of magnetite. The delivery system could be oriented to certain tissues under magnetic field and satisfying magnetic responsiveness was observed.