Targeted RNA delivery using ribonucleoprotein

摘要 沉默RNA（siRNA）是当前医学上相当大的兴趣，因为它可以引起有效的靶向， 特异性敲除几乎任何mRNA，创造了一个有用的和经过验证的遗传替代工具。三种siRNA- 目前，已有7种药物获得FDA批准，另有7种候选药物正在进行3期试验。一个关键 然而，限制siRNA临床应用范围的障碍是体内靶向递送，这是一个“慢性”问题， 一直困扰着几乎所有反义疗法的发展。纳米技术的最新进展 产生了许多纳米载体，如阳离子脂质、聚合物、无机纳米颗粒和肽。虽然 阳离子电荷对于siRNA缩合和内体逃逸是重要的，它干扰特异性 通过非特异性结合大多数蛋白质和细胞来靶向。为了解决这一根本和长期的问题， 问题，在这里，我们建议进一步开发一种用于递送siRNA鸡尾酒的RNA纳米载体 基于我们最近在人RNA结合蛋白上取得的突破（Corey & Gao Nature BME，PCT （美国阶段批准）。经过数百万年的进化优化，这些蛋白质是中性或轻微的 带负电荷，但仍然紧密结合货物RNA，并具有非常高的有效载荷。没有 过量的阳离子电荷与常规的输送技术形成直接对比。通过定向 通过与siRNA靶向配体嵌合体的受控自组装，该复合物同时实现了所有的 有效siRNA递送和癌症治疗所需的性质。

ABSTRACT Silencing RNA (siRNA) is of considerable current interest in medicine because it can elicit potent, target specific knockdown of virtually any mRNA, creating a useful and proven genetic surrogate tool. Three siRNA- based therapies have been FDA-approved, while another seven candidates are in phase 3 trials. A key obstacle limiting the scope of siRNA clinical uses, however, is in vivo targeted delivery, a `chronic' problem that has plagued the development of virtually all antisense therapies. Recent advances in nanotechnology have produced many nanocarriers such as cationic lipids, polymers, inorganic nanoparticles, and peptides. Although the cationic charge is important for siRNA condensation and endosomal escape, it interferes with specific targeting by non-specifically binding to most proteins and cells. To address this fundamental and chronic problem, here we propose to further develop a one-of-its-kind RNA nanocarrier for delivery of siRNA cocktails building on a recent breakthrough we made on human RNA-binding proteins (Corey & Gao Nature BME, PCT filed, US phase granted). Optimized through millions of years of evolution, these proteins are neutral or slightly negatively charged yet still binding to cargo RNA tightly and with a very high payload. The absence of excessive cationic charges is in direct contrast to conventional delivery technologies. Through orientation controlled self-assembly with siRNA-targeting ligand chimeras, the complex simultaneously achieves all the desired properties for efficient siRNA delivery and cancer treatment.