Nanoparticle Dynamics in Polymer Solutions and Melts

该奖项支持小颗粒、药物分子和蛋白质在聚合物、长链样分子拥挤的环境中的运动的理论和计算研究和教育，例如可能在细胞内部和组织网络中实现。越来越多的证据表明，细胞拥挤对小颗粒和蛋白质运动的影响间接影响了许多生物分子现象，包括蛋白质的稳定性和聚集，以及酶促反应。不幸的是，典型的细胞环境由大量不同成分组成，如长链聚合物、基因组DNA和代谢物，这使得很难量化这些基质中负责蛋白质或颗粒运动的特征。本研究旨在开发和使用计算机模拟来研究聚合物溶液中具有代表性的模型系统中小颗粒的运动，以确定(a)拥挤的影响，通过颗粒/蛋白质相对于环境维度的相对大小来量化；(b)粒子/蛋白质与环境的相互作用。在这个项目中得到的理解可以对细胞过程的基本理解和新的纳米粒子疗法的设计产生影响。该项目将为研究生、本科生和高中生提供在生物学和高分子物理学交叉领域进行研究的机会。研究成果还将用于开发基于计算机的教育模块，以说明小型探针和蛋白质在拥挤环境中伴随运动的物理学。该奖项支持聚合物流体中纳米颗粒运动的基础物理学的理论和计算研究和教育。最近，复杂的实验研究已经接触到了大小与聚合物溶液相关长度相当的颗粒的动力学，并发现了一些与胶体颗粒表现出的连续特征不同的有趣行为。该项目旨在开发和使用粗粒度的计算机模拟方法，以确定控制纳米颗粒在从稀释到浓缩的聚合物溶液中的流动性和流变性能的基本物理特性。更具体地说，这项研究将使用计算机模拟和模型来解决两个广泛的问题：(i)基质的非连续的、依赖于尺度的流变性能对聚合物基质中纳米颗粒悬浮液的动力学和流变性能的影响；聚合物-纳米颗粒相互作用对迁移率和悬浮流变性的影响。该项目将包括：研究生、本科生和高中生的研究机会；针对本科、研究生课程和K-12外展活动开发新的模拟和教育模块；协同活动包括组织座谈会，旨在作为聚合聚合物物理和连续介质力学研究的论坛。

NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education on the motion of small particles, drug molecules and proteins in environments crowded with polymers, long chain-like molecules, such as may be realized in cell interiors and tissue networks. Increasing evidence suggests that the influence of cell crowding on the motion of small particles and proteins indirectly influences a number of biomolecular phenomena, including protein stability and aggregation, and enzymatic reactions. Unfortunately, the typical cell environment consists of a soup of a vast number of different components, such as long-chain polymers, genomic DNA, and metabolites, rendering it difficult to quantify the features responsible for protein or particle motion in such matrices. This research is aimed to develop and use computer simulations to study the motion of small particles in a model, representative system of polymeric solutions, to identify the influence of (a) crowding, as quantified by the relative size of the particle/protein to environmental dimensions; and (b) the interactions between the particle/protein and the environment. The understanding derived in this project can have impact on both fundamental understanding of cellular processes and the design of new nanoparticle therapies. The project will include opportunities for graduate, undergraduates and high school students to pursue research in an area at the crossroads of biology and polymer physics. The outcomes of the research will also be used to develop computer-based educational modules to illustrate the physics accompanying motion of small probes and proteins in crowded environments. TECHNICAL SUMMARYThis award supports theoretical and computation research and education on the fundamental physics underlying the movement of nanoparticles in polymeric fluids. Recently, sophisticated experimental studies have accessed the dynamics of particles whose sizes are comparable to the polymer solution correlation lengths, and have unearthed a number of intriguing behaviors which are distinct from the continuum characteristics exhibited by colloidal particles. The PI aims to develop and use coarse-grained computer simulation methodologies to identify the fundamental physics governing the mobility and rheological properties of nanoparticles in polymer solutions ranging from dilute to concentrated conditions. More specifically, this research will use computer simulations and models to address two broad issues: (i) The influence of noncontinuum, scale-dependent rheological properties of the matrix upon the dynamics and rheological properties of nanoparticle suspensions in polymer matrices; (ii) The influence of polymer-nanoparticle interactions upon the mobilities and suspension rheologies. This project will include: research opportunities for graduate, undergraduates and high school students; development of new simulation and educational modules targeting undergraduate, graduate courses and K-12 outreach activities; and synergistic activities involving the organization of colloquia designed to serve as a forum for confluence of research in polymer physics and continuum mechanics.