载siRNA阳离子脂质体的制备

Preparation and characterization of cationic liposomes entrapping siRNA

目的制备载siRNA阳离子脂质体并对其进行制剂学评价。方法利用siRNA与溴化乙锭结合能产生荧光的原理,采用预染溴化乙锭（Ethidium Bromide,EB）琼脂糖凝胶,氨基丁三醇-硼酸-乙二胺四乙酸（Tris-Boric acid-EDTA,TBE）电泳缓冲液将游离siRNA分离并通过凝胶成像分析系统转换数据进行定性和定量,计算载siRNA阳离子脂质体包封率,并考察其阴离子的抵御能力和血清稳定性;利用Malver粒径和zeta电位测定仪对不同载siRNA阳离子脂质体进行评价。结果琼脂糖凝胶电泳法的线性为0.665～13.30 mg·L-1（R2=0.988 3）,回收率为97%-103%,精密度RSD〈2%,阳离子脂质体对siRNA包封率较高,且具有良好的抵御阴离子能力和较强的血清稳定性;载siRNA阳离子脂质体的粒径和zeta电位变化与文献报道一致。结论所制备的载siRNA阳离子脂质体体外性质均良好。

Objective To prepare and characterize cationic liposomes entrapping siRNA. Methods Agarose electrophoresis in TBE solution could be used to separate free siRNA from liposome,which and fluorescence emission after siRNA binding to EB could be applied to test siRNA stability against polyanion and in serum,and determine the encapsulation efficiency of siRNA loaded in cationic liposome; The sizes and zeta potentional of both liposome and lipoplexes were determined by Malvern apparatus. Results The determination method was linear in 0. 665- 13. 30 mg·L- 1with correlation coefficients of 0. 988 3. The recovery was at 97%-103%,and the RSDs were within 2%; It was as literature reported that the sizes and zeta potentional of lipoplexes were different at various weight ratios. Conclusions The entrapment efficiency of lipoplexes is over 80%; and the lipoplexes perform good in stability in serum and resistance against polyanion.