Engineered Organic Particles of Controlled Size, Shape and Surface Chemistry for

描述（由申请人提供）：该项目的总体目标是阐明可控制形状、可控制位点特异性表面化学、可调节颗粒基质组成和可调节模量的有机纳米颗粒进行内吞作用的机制，并利用这些发现来设计哺乳动物细胞内siRNA的细胞内释放，以实现有效的基因敲除。这些信息，结合正在进行的对形状控制颗粒的生物分布的理解，将有助于建立合理设计纳米载体的规则，以有效地在体内递送siRNA。这将使用北卡罗来纳大学开发的一种独特的颗粒合成方法来完成，该方法称为PRINT，即非润湿模板中的颗粒复制。PRINT是新兴的光刻工艺的一个分支，用于制造微电子工业中的设备。在目标1和目标2中，纳米颗粒的组成、大小、形状、表面电荷和配体选择对非靶向和靶向纳米颗粒的细胞摄取的影响将被检查。纳米颗粒的细胞内在化动力学和电荷的影响以及配体在颗粒表面的空间排列和密度将被研究关于颗粒细胞内在化的特定途径。目的3将探索PRINT纳米颗粒在体外非靶向和靶向递送siRNA的合理设计。当PRINT颗粒进入细胞时，颗粒载体将根据刺激诱导的生物或化学降解机制释放siRNA。通过荧光素酶基因沉默监测细胞内递送的有效性将被评估为颗粒基质组成、颗粒大小和形状以及内化途径的函数。目的4将探索PRINT纳米颗粒的合理设计，用于靶向siRNA的体内递送。将包裹抗荧光素酶siRNA的PRINT纳米颗粒用细胞特异性配体（叶酸、转铁蛋白）修饰，然后静脉注射到荷瘤小鼠体内。siRNA递送到肿瘤的功效和效率将作为颗粒表面和基质化学的功能来评估。了解颗粒表面化学和形状对体外和体内有效转染的详细相互作用具有重要意义。

DESCRIPTION (provided by applicant): The overall goal for this project is to elucidate the mechanisms by which organic nanoparticles of controlled shape, controlled site-specific surface chemistry, tunable particle matrix composition and tunable modulus undergo endocytosis and to use these findings to engineer the intracellular release of siRNA within mammalian cells to achieve effective gene knockdown. This information, in combination with on-going efforts to understand the bio-distribution of shape controlled particles, will help to establish the rules for the rational design of nano-carriers for the effective in vivo delivery of siRNA. This will be accomplished using a unique particle synthesis method developed at the University of North Carolina called PRINT, Particle Replication in Non- wetting Templates. PRINT is an off-shoot of the emerging lithographic processes used to fabricate devices in the microelectronics industry. In aims 1 and 2, the effect of nanoparticle composition, size, shape, surface charge and ligand choice on the cellular uptake of non-targeted and targeted nanoparticles will be examined. The kinetics of cellular internalization of the nanoparticles and the effect of charge and the spatial arrangement and the density of the ligands on the particle surface will be investigated with regard to specific pathways for cellular internalization of particles. Aim 3 will explore the rational design of PRINT nanoparticles for non-targeted and targeted in vitro delivery of siRNA. As the PRINT particles enter a cell, the particulate carriers will release the siRNA based on a stimuli induced biological or chemical degradation mechanism. The effectiveness of intracellular delivery monitored by luciferase gene silencing will be evaluated as a function of particle matrix composition, particle size and shape and pathway of internalization. Aim 4 will explore rational design of PRINT nanoparticles for targeted in vivo delivery of siRNA. The PRINT nanoparticles with encapsulated anti-luciferase siRNA will be decorated with cell specific ligands (folate, transferrin) and intravenously injected into tumor bearing mice. The efficacy and efficiency of siRNA delivery to the tumor will be evaluated as a function of particle surface and matrix chemistries. Understanding the detailed interplay between particle surface chemistry and shape on effective transfection both in vitro as well as in vivo is of significant importance. PUBLIC HEALTH RELEVANCE: Small interfering RNA (siRNA) has the potential to revolutionize the treatment of a number of life threatening human diseases, particularly cancer, but one obstacle facing researchers and companies attempting to develop siRNA therapies, or any type of nucleic acid therapeutic, is efficient and specific delivery of the polyanionic molecules into the cells, tissues or organ systems of choice. Using a technique known as PRINTTM (Particle Replication in Non-wetting Templates), we are able to fabricate nanoparticles with precise control over the particle size, shape, composition, cargo and surface properties to create truly engineered drug therapies that can be used to overcome the obstacles facing researchers and to provide the tools for the rational design of nano-carriers for the effective delivery of therapeutics in vitro and in vivo.