Nanobiotechnology Center, Markey Cancer Center and Department of Pharmaceutical Sciences/College of Pharmacy, University of Kentucky, Lexington, KY 40536, United States.
Center for RNA Nanobiotechnology and Nanomedicine, Division of Pharmaceutics and Pharmaceutical Chemistry/College of Pharmacy, College of Medicine, Dorothy M. Davis Heart and Lung Research Institute and James Comprehensive Cancer Center, The Ohio State Universtiy, Columbus, OH 43210, United States.
J Control Release. 2018 Apr 28;276:17-29. doi: 10.1016/j.jconrel.2018.02.014. Epub 2018 Feb 14.
RNA can serve as powerful building blocks for bottom-up fabrication of nanostructures for biotechnological and biomedical applications. In addition to current self-assembly strategies utilizing base pairing, motif piling and tertiary interactions, we reported for the first time the formation of RNA based micellar nanoconstruct with a cholesterol molecule conjugated onto one helical end of a branched pRNA three-way junction (3WJ) motif. The resulting amphiphilic RNA micelles consist of a hydrophilic RNA head and a covalently linked hydrophobic lipid tail that can spontaneously assemble in aqueous solution via hydrophobic interaction. Taking advantage of pRNA 3WJ branched structure, the assembled RNA micelles are capable of escorting multiple functional modules. As a proof of concept for delivery for therapeutics, Paclitaxel was loaded into the RNA micelles with significantly improved water solubility. The successful construction of the drug loaded RNA micelles was confirmed and characterized by agarose gel electrophoresis, atomic force microscopy (AFM), dynamic light scattering (DLS), and fluorescence Nile Red encapsulation assay. The estimate critical micelle formation concentration ranges from 39 nM to 78 nM. The Paclitaxel loaded RNA micelles can internalize into cancer cells and inhibit their proliferation. Further studies showed that the Paclitaxel loaded RNA micelles induced cancer cell apoptosis in a Caspase-3 dependent manner but RNA micelles alone exhibited low cytotoxicity. Finally, the Paclitaxel loaded RNA micelles targeted to tumor in vivo without accumulation in healthy tissues and organs. There is also no or very low induction of pro-inflammatory response. Therefore, multivalence, cancer cell permeability, combined with controllable assembly, low or non toxic nature, and tumor targeting are all promising features that make our pRNA micelles a suitable platform for potential drug delivery.
RNA 可以作为构建生物技术和生物医学应用的纳米结构的强大构建块。除了当前利用碱基配对、基序堆积和三级相互作用的自组装策略外,我们还首次报道了胆固醇分子连接到分支 pRNA 三链结(3WJ)基序的一个螺旋末端,形成基于 RNA 的胶束纳米结构。所得的两亲性 RNA 胶束由亲水 RNA 头和共价连接的疏水性脂质尾组成,可通过疏水相互作用在水溶液中自发组装。利用 pRNA 3WJ 分支结构,组装的 RNA 胶束能够携带多个功能模块。作为递药的概念验证,紫杉醇被负载到 RNA 胶束中,其水溶性得到显著提高。通过琼脂糖凝胶电泳、原子力显微镜 (AFM)、动态光散射 (DLS) 和荧光尼罗红包封测定证实和表征了负载药物的 RNA 胶束的成功构建。估计临界胶束形成浓度范围为 39 nM 至 78 nM。负载紫杉醇的 RNA 胶束可以进入癌细胞并抑制其增殖。进一步的研究表明,负载紫杉醇的 RNA 胶束通过 Caspase-3 依赖性诱导癌细胞凋亡,而 RNA 胶束本身表现出低细胞毒性。最后,负载紫杉醇的 RNA 胶束在体内靶向肿瘤,而不会在健康组织和器官中积累,也不会或很少引起炎症反应。因此,多价性、癌细胞通透性、可控组装、低毒性或非毒性以及肿瘤靶向性都是很有前途的特征,使我们的 pRNA 胶束成为潜在药物递送的合适平台。