siRNA-aptamer chimeras on nanoparticles: preserving targeting functionality for effective gene silencing.
siRNA-aptamer chimeras on nanoparticles: preserving targeting functionality for effective gene silencing.
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DOI：
10.1021/nn202772p
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发表时间：
2011-10-25
期刊：
影响因子：
17.1
通讯作者：
Gao X
中科院分区：
文献类型：
--
作者：
Bagalkot V;Gao X
siRNA-适体嵌合体由于其突出的靶向能力以及嵌合体与天然核糖核酸酶（Dicer）加工的相容性而成为一种非常有前途的细胞类型特异性递送siRNA的方法。然而，对于有效的RNA干扰（RNAi），必须解决额外的挑战，特别是如何在进入细胞后将siRNA从内体中取出，以及当嵌合体与递送载体组合时如何保持适体靶向特异性。在这里，我们报告了一个合理设计的纳米颗粒载体，同时显示大表面积的高siRNA有效载荷，暴露的适体的特异性靶向，质子海绵效应的内体逃逸，和荧光成像和定量。这项工作的一个关键概念是通过两步过程将嵌合体接枝到纳米颗粒表面：首先通过非共价相互作用将siRNA固定到纳米颗粒上，以促进细胞内解包装并减少纳米颗粒表面电荷（避免适体和纳米颗粒之间的非特异性静电相互作用），然后将siRNA和适体偶联，保持构象和高可及性。与常规的将siRNA-适体嵌合体吸附到具有随机取向和构象的纳米颗粒上的一步吸附相比，这并没有引起比非靶向纳米颗粒-siRNA复合物更好的RNAi效果（总细胞群提高约6-8%），在相同的RNA浓度下，我们的方法显示出选择性基因沉默，并使总细胞群中沉默的细胞比非沉默细胞多34%。靶向纳米颗粒-siRNA复合物。使用纳米颗粒-嵌合体复合物的RNAi效率的这种显著差异与由纳米颗粒表面上的适体构象（完整与随机）引起的细胞摄取差异直接相关。
siRNA-aptamer chimera is emerging as a highly promising approach for cell-type specific delivery of siRNA due to the outstanding targeting capability of aptamer and the compatibility of chimera with native ribonuclease (Dicer) processing. For efficient RNA interference (RNAi), however, additional challenges must be addressed, in particular how to get siRNA out of endosome after cell entry and how to preserve aptamer targeting specificity when chimeras are combined with delivery carriers. Here, we report a rationally designed nanoparticle vector that simultaneously displays large surface area for high siRNA payload, exposed aptamer for specific targeting, proton sponge effect for endosome escape, and fluorescence for imaging and quantification. A key concept of this work is to graft chimeras onto nanoparticle surface via a two-step process: first immobilizing siRNA onto nanoparticle via non-covalent interactions to facilitate intracellular unpackaging and reduce nanoparticle surface charge (avoiding non-specific electrostatic interactions between aptamers and nanoparticles), and then coupling siRNA and aptamer with retained conformation and high accessibility. Compared with conventional one-step adsorption of siRNA-aptamer chimeras onto nanoparticles with random orientations and conformations, which does not elicit much improved RNAi effect than non-targeted nanoparticle-siRNA complexes (~6-8% improvement of the total cell population), under the same RNA concentration our approach shows selective gene silencing and enables 34% more silenced cells of the total cell population over non-targeted nanoparticle-siRNA complexes. This remarkable difference in RNAi efficiency using nanoparticle-chimera complexes is directly related to cell uptake discrepancy resulted from aptamer conformation on nanoparticle surface (intact vs. random).
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影响因子：
46.9
作者：
Dassie, Justin P.;Liu, Xiu-ying;Thomas, Gregory S.;Whitaker, Ryan M.;Thiel, Kristina W.;Stockdale, Katie R.;Meyerholz, David K.;McCaffrey, Anton P.;McNamara, James O., II;Giangrande, Paloma H.
通讯作者：
Giangrande, Paloma H.
影响因子：
17.1
作者：
Meng H;Liong M;Xia T;Li Z;Ji Z;Zink JI;Nel AE
通讯作者：
Nel AE
影响因子：
12.4
作者：
Nishina, Kazutaka;Unno, Toshinori;Yokota, Takanori
通讯作者：
Yokota, Takanori
影响因子：
4.7
作者：
Derfus, Austin M.;Chen, Alice A.;Bhatia, Sangeeta N.
通讯作者：
Bhatia, Sangeeta N.
影响因子：
64.8
作者：
Soutschek, J;Akinc, A;Vornlocher, HP
通讯作者：
Vornlocher, HP