Developing a delivery vehicle to protect siRNA from degradation is a significant challenge. To solve this challenge, researchers attempted to use protein-based nanoparticles to deliver siRNA with limited to moderate success. However, a systematic investigation of comparing the ability of different protein-based nanoparticles as vehicles to deliver siRNA stably within cells is still unavailable. Therefore, in this study we synthesized a library of both non-targeted (proteinsiRNA) nanoparticles (NPs) and targeted (antibody conjugated protein-siRNA) NPs and evaluated ability to stably deliver siRNA in to cells to silence the gene of interest. We investigated nanoparticles of casein, bovine serum albumin, and gelatin for the delivery of siRNA. We synthesized and characterized a total of 12 nanoconjugates; in these conjugates, we either encapsulated, electrostatically attached, or covalently conjugated siRNA. We evaluated the efficiency of attaching siRNA to nanoconjugates, stability, and cellular delivery. The ability of siRNA to silence the protein of interest in cancer cells was also investigated. Among non-targeted conjugates, BSA matrix imparted relatively high stability to siRNA when encapsulated. Among targeted nanoconjugates, gelatin nanoparticles rendered high stability to siRNA upon covalent conjugation to the surface. On comparing with both targeted and non-targeted NPs for release of siRNA within cells, antibody-gelatin-siRNA conjugate exhibited high release and functional activity (down-regulation of target protein levels) within the cells as confirmed by both fluorescence imaging and Western blotting. In summary, our investigations show that targeted gelatin nanoparticles and non-targeted BSA nanoparticles possess high stability and excellent gene suppression capabilities and warrants further studies. We can extend the results from this study to develop stable siRNA delivery vehicles to specifically silence the protein of interest.

中文翻译：

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基于蛋白质的纳米粒子对小干扰RNA稳定传递的系统评价。

开发保护siRNA免受降解的运载工具是一项重大挑战。为了解决这一挑战，研究人员试图使用基于蛋白质的纳米颗粒来递送siRNA，但成功率有限。然而，仍然无法进行系统的研究来比较不同的基于蛋白质的纳米颗粒作为载体在细胞内稳定传递siRNA的能力。因此，在这项研究中，我们合成了非靶向（蛋白siRNA）纳米颗粒（NPs）和靶向（抗体偶联蛋白-siRNA）NPs的文库，并评估了将siRNA稳定地传递到细胞中以沉默目的基因的能力。我们研究了酪蛋白，牛血清白蛋白和明胶的纳米颗粒用于siRNA的传递。我们合成并表征了总共12种纳米共轭物。在这些结合物中，我们要么封装，静电附着或共价结合的siRNA。我们评估了将siRNA附着于纳米缀合物的效率，稳定性和细胞递送。还研究了siRNA沉默癌细胞中目的蛋白的能力。在非靶向缀合物中，BSA基质在包封时赋予siRNA较高的稳定性。在靶向纳米共轭物中，明胶纳米颗粒在与表面共价结合后对siRNA具有很高的稳定性。通过与靶向和非靶向NP比较细胞内siRNA的释放，抗体-明胶-siRNA共轭物在细胞内显示出高释放和功能活性（目标蛋白水平下调），这已通过荧光成像和Western blot证实。综上所述，我们的研究表明，靶向明胶纳米颗粒和非靶向BSA纳米颗粒具有很高的稳定性和出色的基因抑制能力，值得进一步研究。我们可以扩展这项研究的结果，以开发稳定的siRNA递送载体，以特异性沉默目的蛋白。