RNA Nanosystem for Posterior Eye Drug Delivery

RNA纳米技术提供了设计简单的分子，具有DNA和 可以在治疗中使用。然而，RNA纳米技术中的一个主要问题是，RNA分子 相对不稳定，如在体内降解和超低浓度解离后 行政管理。玻璃体腔注射是输送大分子治疗药物的最常用方法 用来治疗疾病的眼睛的后部。反复玻璃体内注射会导致 对眼睛有严重的不良影响。对于小药物分子，可以使用全身给药，但这 全身毒性使给药途径变得复杂。对一种更有效的药物的需求尚未得到满足 分娩方法在治疗眼后部疾病中的应用。我们最近研究了核糖核酸纳米颗粒 来源于噬菌体phi29 DNA包装RNA(PRNA)的三向连接(3WJ) 用于眼科药物输送的包装马达。这些纳米粒子在热力学和化学上都是稳定的。 在体外和体内都可以，并且可以包含具有不同功能的多个模块，例如RNA适体， 报告部分，和治疗性的siRNA、miRNA或其他化学药物或配体作为亚单位都在同一 纳米粒子。我们的初步研究表明，PRNA纳米颗粒(PRNA纳米)是 结膜下后内化于角膜、视网膜色素上皮和视网膜的细胞 注射于小鼠体内。这表明结膜下注射PRNA纳米粒子作为一种有效的 以RNA为基础的治疗剂对眼后段细胞的药物释放系统：PRNA Nano可以同时克服RNA分子的稳定性和后部眼球传递的问题。预赛 研究还表明，PRNA纳米颗粒的传递和保留与颗粒大小有关，并且 存在一个最佳的大小范围，使其有效地输送到眼睛的细胞。该计划的目标 目前的项目是(A)确定用于眼部给药的最佳PRNA纳米粒，(B)展示其能力 (C)开发一种上巩膜； 植入系统，以延长这些纳米颗粒的输送。不同尺寸和模数的PRNA纳米粒子 将构建亚单位，并评估有效的眼内给药和治疗效果 结膜下注射动物模型。巩膜外植入物是可再填充的，并放置在巩膜上。 结膜下或Tenon下口袋，提供持续的纳米粒输送。最终目标是 开发一个使用PRNA技术的眼部药物输送平台，通过 眼周入路(一种比玻璃体内注射侵入性小的入路)。本项目将研究 PRNA纳米粒子与巩膜外植入物联合应用验证这一新概念的可行性 技术

RNA nanotechnology provides molecules that have the simplicity in design with the characteristics of DNA and can be used in therapies. However, a major problem in RNA nanotechnology is that RNA molecules are relatively unstable such as their degradation in vivo and dissociation at ultra-low concentration after administration. Intravitreal injection is the most common method to deliver macromolecular therapeutic agents to the posterior segment of the eye for the treatments of diseases. Repeated intravitreal injection can cause severe adverse effects to the eye. For small drug molecules, systemic administration can be used but this route of administration is complicated by systemic toxicity. There is an unmet need of a more effective drug delivery method in the treatment of posterior eye diseases. We have recently studied RNA nanoparticles derived from the three-way junction (3WJ) of the packaging RNA (pRNA) of bacteriophage phi29 DNA packaging motor for ocular drug delivery. These nanoparticles are thermodynamically and chemically stable both in vitro and in vivo and can harbor multiple modules with different functionalities such as RNA aptamer, reporter moiety, and therapeutic siRNA, miRNA, or other chemical drugs or ligands as subunits all in the same nanoparticles. Our preliminary studies have shown that the pRNA nanoparticles (pRNA nano) were internalized in the cells in the cornea, retinal pigment epithelium, and retina in the eye after subconjunctival injection in mice in vivo. This suggests the potential of subconjunctival injection of pRNA nano as an efficient drug delivery system of RNA-based therapeutic agents to the cells in the posterior segment of the eye: pRNA nano can overcome both the RNA molecule stability and posterior eye delivery problems. The preliminary studies have also suggested that the delivery and retention of pRNA nano are particle size dependent and the existence of an optimal size range for their effective delivery to the cells in the eye. The objectives of the present project are to (a) determine the optimal pRNA nano for ocular drug delivery, (b) demonstrate the ability of pRNA nano to deliver therapeutic agents to treat posterior eye disease, and (c) develop an episcleral implant system for prolonged delivery of these nanoparticles. pRNA nano of different sizes and module subunits will be constructed and evaluated for effective intraocular delivery and therapeutic effects after subconjunctival injection in animal models. The episcleral implant is refillable and is placed on the sclera in the subconjunctival or sub-Tenon pocket to provide sustained delivery of the nanoparticles. The ultimate goal is to develop a platform of ocular drug delivery using the pRNA technology for nucleotide-based therapies via the periocular route (a less invasive approach than intravitreal injection). The present project will examine the feasibility of the combined pRNA nano and episcleral implant approach for the proof of concept of this new technology.