Shape Control and Transfection of Self-assembled Polymer-DNA Nanoparticles

描述(申请人提供)：这项研究的总体目标是从机理上理解自组装DNA纳米颗粒的形状控制，并测试纳米颗粒形状可以影响其细胞摄取、细胞内运输和基因传递效率的假设。最近的几项研究提出了这样的前景，即病毒颗粒和各种类型的合成纳米颗粒的形态是它们传输特性和生物功能的重要决定因素。我们开发了一种方法来自组装含有DNA的纳米颗粒，这些纳米颗粒具有几种不同的形状(球形、杆状和蠕虫状)，类似于一些病毒颗粒，用于基因转染。这些纳米粒子是了解DNA诱导自组装的机制以及纳米粒子形状对其稳定性、细胞-纳米粒子相互作用、转染率和体内转运动力学的影响的理想系统。利用这项探索性拨款，我们计划(1)确定有效控制纳米颗粒形状和大小的关键实验参数，并使用实验和计算相结合的建模方法了解聚乙二醇化聚阳离子在DNA缩合过程中形状控制的机制；(2)在肝靶向基因传递模型中展示纳米颗粒形状对细胞摄取、细胞内转运和转染率的依赖。这项研究将从机理上了解DNA/聚乙二醇聚阳离子纳米颗粒自组装的主要驱动力，并确定涉及其形状控制的关键参数。这将为控制DNA/聚合物纳米粒子的大小和形状提供一种有效的方法，该方法可适用于各种聚乙二醇化的基因载体，用于合成形状或形貌高度可控的纳米粒子。

DESCRIPTION (provided by applicant): The overall objective of this study is to develop a mechanistic understanding of shape control of self-assembled DNA nanoparticles, and to test the hypothesis that nanoparticle shape can influence their cellular uptake, intracellular trafficking and gene delivery efficiency. Several recent studies have raised the prospect that the morphology of virus particles and various types of synthetic nanoparticles is an important determinant for their transport properties and biological functions. We have developed a method for the self-assembly of DNA-containing nanoparticles with several distinct shapes (spherical, rod-like and worm-like) similar to some viral particles for the purpose of gene transfection. Such nanoparticles are ideal systems for understanding the mechanism of DNA-induced self-assembly and the effect of nanoparticle shape on their stability, cell- nanoparticle interactions, transfection efficiency and in vivo transport kinetics. With this Exploratory Grant, we plan (1) to determine the key experimental parameters that effectively control the shape and size of nanoparticles, and to understand the mechanism of shape control in DNA condensation by PEGylated polycations using a combined experimental and computational modeling approach; and (2) to demonstrate nanoparticle shape dependence in cellular uptake, intracellular trafficking and transfection efficiency in vitro and in vivo in a liver-targeted gene delivery model. This study will provide a mechanistic understanding of the major driving forces for the self-assembly of DNA/PEG-polycation nanoparticles and identify key parameters involved in their shape control. It will offer an effective method to control the size and shape of DNA/polymer nanoparticles that can be applicable to a variety of PEGylated gene carriers in synthesizing nanoparticles with high degree of control over their shapes or morphologies.