Optimizing RNA nanoparticles size and shape for enhancing cancer targeting and treatment

项目总结 在过去的几年里，RNA纳米技术发展迅速。这种纳米技术包括 将多个功能模块集成到一个纳米颗粒中，其中的支架、配体、 治疗药物和调节剂可以主要或完全由RNA组成。我们已经构建了RNA 大小、形状和化学计量比不同的纳米颗粒，具有很高的化学和热力学稳定性 并展示了它们含有不同官能团的能力，如siRNA、miRNA、核酶、药物、 以及以RNA适体为靶标的癌症。所有功能模块保持原汁原味的折叠和独立 体内特定细胞结合、基因沉默和癌症靶向的功能。在全身注射时 荷瘤小鼠，RNA纳米颗粒与异种移植瘤和转移性肿瘤特异性强结合 给药后3-4小时，健康的重要器官和组织中几乎没有积聚。核糖核酸 纳米粒无毒，表现出良好的生物分布和药代动力学特征。 我们的长期目标是推动RNA纳米粒子成为治疗糖尿病的新一代药物 诊所里的癌症。该项目的短期目标是表征RNA纳米颗粒在体内的行为 体外和体内，旨在提高特定细胞靶向、内化和细胞内的效率 转运，良好的生物分布而不被困在肝脏，内吞逃逸，以及肿瘤消退。 这些研究基于三个中心假设：(1)细胞内转运途径和内体 逃逸对于有效的癌症治疗至关重要；(2)RNA的生物分布和药理学特征 纳米粒子是形状和大小相关的；以及，(3)由RNA纳米粒子引发的免疫反应 高度依赖于RNA序列、化学修饰、大小、形状和化学计量比。向我们的 目标，我们将(1)系统地剖析RNA纳米颗粒所走的细胞内途径，并增强 (2)检查药代动力学(PK)、药效学(PD)； RNA纳米粒的生物分布，目的是以最小的蓄积增强肿瘤靶向性 健康的器官；以及，(3)评估RNA纳米粒的免疫反应，以将非特异性方面降至最低 效果，以及开发通过结合免疫刺激剂来刺激免疫系统的方法 用于癌症免疫治疗的RNA纳米粒子的模块。在完成这些临床前研究后，我们 我将鉴定出几个形状、大小和化学计量比都经过优化的RNA纳米粒子 良好的安全性和高效的治疗效果符合FDA的新药研究指南 用于启动临床试验。

PROJECT SUMMARY RNA nanotechnology has progressed rapidly during the past several years. This nanotechnology includes the integration of multiple functional modules into one nanoparticle, of which the scaffolds, ligands, therapeutics, and regulators can be composed mainly or exclusively of RNA. We have constructed RNA nanoparticles of diverse size, shape, and stoichiometry displaying high chemical and thermodynamic stability and demonstrated their ability to harbor different functional groups, such as siRNA, miRNA, ribozyme, drug, and cancer targeting RNA aptamer. All functional modules retain their authentic folding and independent functionalities for specific cell binding, gene silencing, and cancer targeting in vivo. Upon systemic injection in tumor bearing mice, RNA nanoparticles bind to xenograft and metastatic tumors specifically and strongly with little to no accumulation in healthy vital organs and tissues 3-4 hours post-administration. The RNA nanoparticles are non-toxic and display favorable biodistribution and pharmacokinetic profiles. Our long-term goal is to promote RNA nanoparticles as a new generation of drug for the treatment of cancers in the clinic. The short-term goal of this project is to characterize the behavior of RNA nanoparticles in vitro and in vivo, with an aim to improve the efficiency for specific cell targeting, internalization and intracellular trafficking, favorable biodistribution without entrapment in liver, endosome escape, and tumor regression. These studies are based on three central hypotheses: (1) intracellular trafficking pathways and endosome escape are critical for effective cancer therapy; (2) biodistribution and pharmacological profiles of RNA nanoparticles are shape and size dependent; and, (3) immune responses elicited by RNA nanoparticles are highly dependent on RNA sequence, chemical modifications, size, shape, and stoichiometry. To address our goals, we will (1) systemically dissect the intracellular pathways taken by RNA nanoparticles and enhance their endosome escape capabilities; (2) inspect the pharmacokinetics (PK); pharmacodynamics (PD); and biodistribution of RNA nanoparticles with the goal of enhancing cancer targeting with minimal accumulation in healthy organs; and, (3) evaluate the immune responses of RNA nanoparticles to minimize non-specific side effects, as well as develop methods to stimulate the immune system by incorporating immuno-stimulatory modules to RNA nanoparticles for cancer immunotherapy. Upon completion of these pre-clinical studies, we will have identified several RNA nanoparticles with optimized shape, size, and stoichiometry displaying favorable safety profiles and high therapeutic efficacy to comply with FDA Investigational New Drug guidelines for initiating clinical trials.