D-α-生育酚-聚(2-乙基-2-唑啉)琥珀酸酯修饰siRNA脂质复合物的构建及初步评价

Construction and Preliminary Evaluation of Lipid Complex of siRNA Modified by D-α-tocopheryl Poly(2-ethyl-2-oxazoline) Succinate

目的制备D-α-生育酚-聚(2-乙基-2-唑啉)琥珀酸酯[D-α-tocopheryl poly(2-ethyl-2-oxazoline)succinate,TPOS]修饰小干扰RNA(small interfering RNA,siRNA)脂质复合物(TPOS-L/siRNA)。方法以普通siRNA脂质复合物(CLs/siRNA)和PEG修饰CLs/siRNA(PEG-L/siRNA)为对照,对TPOS-L/siRNA的包封率、形态、稳定性、体外释放、细胞摄取等进行评价。结果根据正负电荷的静电吸引作用通过直接混合方法等体积混合空白CLs和siRNA,得到CLs/siRNA。CLs/siRNA具有脂质双分子层结构,包封率为(86.68±1.41)%,粒径小于200 nm。TPOS或PEG-DSPE修饰后,对CLs/siRNA包封率和粒径基本无影响,而且均能赋予脂质复合物良好的稳定性;同时TPOS-L/siRNA具有较好的p H敏感性,能够响应微酸环境,细胞摄取明显增强。结论 TPOS能够构建良好的siRNA载体,并能增加该纳米载体的稳定性和p H敏感性。

OBJECTIVE To prepare small interfering RNA（siRNA） lipid complexes （TPOS-L/siRNA） modified by D-α-tocopheryl poly （2-ethyl-2-oxazoline） succinate （TPOS）.METHODS The conventional siRNA lipid complexes （CLs/siRNA） and PEGylated CLs/siRNA （PEG-L/siRNA） were used as controls. CLs/siRNA was prepared by mixing blank CLs and siRNA directly of equal volume according to the electrostatic interaction of positive and negative charges. The encapsulation efficiency, morphology, stability, in vitro release and cell uptake of TPOS-L/siRNA were investigated.RESULTS The CLs/siRNA had obvious lipid bilayer structure, the encapsulation efficiency （EE） was （86.68±1.41）%, and the particle size of CLs/siRNA was less than 200 nm. The modification with TPOS or PEG-DSPE had no significant effect on the EE and particle size of CLs/siRNA, which could endow the lipid complexes with good stability. In addtion, TPOS-L/siRNA had good pH-sensitive property, and could respond to slightly acidic environment, which significantly enhanced the cell uptake.CONCLUSION TPOS can construct good siRNA carrier and increase the stability and pH sensitivity of the nanocarrier.