| 摘要: |
| 目的 制备靶向输送针对核糖核苷酸还原酶RR小亚基M2 （RRM2）的siRNA （RRM2-siRNA）的聚N-异丙基丙烯酰胺/聚乙烯亚胺（PNIPAM/PEI）纳米凝胶，通过研究其体外的抗肿瘤效应，以期构建新型靶向纳米凝胶递送基因系统。方法 采用自由基接枝共聚合（radical graft copolymerization）反应制备具有“核-壳”结构的PNIPAM/PEI聚阳离子温度敏感型纳米凝胶，评价其粒径、zeta电位等理化性质；根据电荷相互作用原理，并通过偶联抗人表皮生长因子受体2 （Her2）抗体，形成包裹RRM2-siRNA的靶向性PNIPAM/PEI-siRNA纳米凝胶复合体。利用凝胶电泳确定PNIPAM/PEI-siRNA纳米凝胶复合体包裹siRNA效果，通过荧光显微镜定性观察和流式细胞术定量检测人胃癌细胞NCI-N87对该纳米凝胶复合体的摄取情况，利用qPCR法检测该纳米凝胶递送siRNA后靶基因RRM2的表达情况，用Transwell 法检测该纳米凝胶复合体对NCI-N87细胞迁移的影响。结果 本研究合成具有“核-壳”结构的温度敏感型PNIPAM/PEI纳米凝胶，颗粒均匀，粒径为359.8 nm，zeta电位为21.4 mV。在此基础上，我们制备出靶向凝胶包裹RRM2-siRNA的纳米凝胶复合体，确定最佳包裹比例为N/P=60 （N/P:聚阳离子纳米凝胶中氨基与质粒DNA中磷酸基的摩尔比）。不同温度下（37 ℃、42 ℃）细胞内吞实验证实，该纳米凝胶复合体具有良好的靶向性和温度响应性，且可以下调靶基因RRM2的表达，抑制NCI-N87细胞的迁移。结论 成功制备抗体靶向的PNIPAM/PEI聚阳离子温度敏感型纳米凝胶，其可以结合并投递siRNA进入靶细胞，该纳米复合体可以作为新型抗肿瘤基因治疗的给药系统。 |
| 关键词: 纳米凝胶 抗体靶向 温度响应性 药物递送系统 小分子干扰RNA |
| DOI：10.16781/j.0258-879x.2017.06.0720 |
| 投稿时间：2017-05-10修订日期：2017-06-02 |
| 基金项目:国家自然科学基金（31470964，81171450） |
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| In vitro anti-tumor effect of RRM2-siRNA based on active and passive dual targeted nanogel |
| ZHANG Li,WANG Ying,JIN Chong,DONG Xia,LI Wei* |
(International Joint Cancer Institute, Second Military Medical University, Shanghai 200433, China
*Corresponding author) |
| Abstract: |
| Objective To prepare antibody-targeting temperature-sensitive polylated N-isopropylacrylamide/polyethyleneimine (PNIPAM/PEI) nanogel for delivering siRNA against ribonucleotide reductase (RR) subunit M2 (RRM2, RRM2-siRNA) and to establish a new targeted nano-gel delivery system for anti-tumor therapy by studying its anti-tumor ability in vitro. Methods We synthesized the core-shell temperature-sensitive PNIPAM/PEI nanogel by radical graft copolymerization and evaluated its chemo-physical properties (such as, size and zeta potential) using transmission electron microscopy (TEM). According to the principle of charge interaction, the PNIPAM/PEI-siRNA nanogel encapsulated RRM2-siRNA was prepared by conjugating anti-human epidermal growth factor receptor 2 (Her2) antibody. The effect of PNIPAM/PEI-siRNA nanogel complex encapsulated siRNA was determined by agarose gel electrophoresis. The in vitro uptake of NCI-N87 cells by nanogel complex was quantitatively observed by fluorescence microscopy and flow cytometry (FCM). The expression of RRM2 after RRM2 interference using nanogel-siRNA complex in NCI-N87 cells was tested by realtime PCR. The tumor migration suppressing effect of the nanogel complex on Her2-positive tumor cells was determined by Transwell assay. Results The core-shell temperature-responsive PNIPAM/PEI nanogel was synthesized by radical graft copolymerization, with homogeneous size of 359.8 nm, and zeta potential of 21.4 mV. Furthermore, the nanogel complexes encapsulated RRM2-siRNA with different ratios of N/P (N/P ratio: the molar ratio of nitrogen-from-polyethylenimine to phosphate-from-RNA) were prepared and the electrophoresis results showed that the optimal N/P ratio was 60. The cellular uptake experiment showed that the nanogel had good temperature sensitivity and tumor targeting ability at different temperatures (37 ℃, 42 ℃); and the nanogel complex down-regulated the expression of RRM2 and inhibited the migration of NCI-N87 cells. Conclusion The antibody-targeting temperature-sensitive PNIPAM/PEI nanogel is successfully prepared, and it can bind and deliver siRNA into target cells and can be used as a new drug delivery system for anti-tumor therapy. |
| Key words: nanogel antibody-targeting temperature-response drug delivery system small interfering RNA |
