Physical nature of particle transport in elastically responsive hydrogels: one and two particle microrheology

弹性响应水凝胶中颗粒传输的物理性质：一颗粒和二颗粒微流变学

• 批准号: 464628393
• 负责人: Professor Dr. Ralf Metzler
• 金额: --
• 依托单位: Institut für Physik und Astronomie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/464628393?language=en
• 关键词: Physical; nature; particle; transport; elastically

Designs for modern clinical diagnostic tools utilise the diffusion ofpathogens such as viruses into hydrogels, in which pathogens get in contactwith functionalised units and give rise to detectable optical or mechanicalsignals. Nature effectively protects various tissues from bacterial andviral invasion using gel-like mucus films, which are almost impenetrableto specific pathogens. This project combines extensive simulations andanalytical arguments to answer the physical question on how thermallydriven tracer particles, which are larger than the typical network mesh,diffuse in elastic networks. In particular, we address the connectionbetween the size and shape of the tracer particle and its mobility in thegel network and follow up on questions such as: What is the maximal sizeof the particle such that it can still penetrate into and diffuse throughthe gel? Which role does the tracer shape play? What are the correlationsbetween the motion of the tracer and the surrounding gel network? Whicheffect does spatial disorder of the gel have on the tracer mobility? And finally,which role is played by the degree of deformability of the tracer, thatis, can we detect significant differences between motion of hard-coreversus soft-core tracer particles? Similar questions will be asked for thecorrelated motion of two vicinal tracers in the gel, a setup typically usedin two-particle microrheology. The diffusive characteristics of the tracerwill be quantified in terms of the ensemble and time averaged particledisplacements, the non-Gaussianity and non-ergodicity parameters, as wellas the correlation and probability distribution functions of the diffusingparticles. The results of this project will provide an important input forthe analysis of microrheology experiments and allow novel insights intothe physico-chemical properties of particle diffusion in heterogeneouslystructured and elastically responsive environments, such as those insideliving biological cells, in multicellular organisations, in mucus films,or gels used for clinical diagnostic tools.

现代临床诊断工具的设计利用病毒等病原体扩散到水凝胶中，其中病原体与功能化单元接触并产生可检测的光学或机械信号。大自然使用凝胶状的粘液膜有效地保护各种组织免受细菌和病毒的入侵，这些粘液膜几乎是特定病原体无法穿透的。该项目结合了广泛的模拟和分析论证，以回答关于热驱动示踪粒子如何在弹性网络中扩散的物理问题。特别是，我们解决的connectionbetween的示踪剂颗粒的大小和形状和它的流动性在thegelnetwork和跟进的问题，如：什么是最大尺寸的颗粒，使它仍然可以渗透到和扩散通过凝胶？跟踪器形状扮演什么角色？示踪剂的运动与周围凝胶网络之间有何相关性？凝胶的空间无序对示踪剂的迁移率有什么影响？最后，示踪剂的变形程度起着什么作用，即，我们能否检测出硬核示踪剂粒子和软核示踪剂粒子运动之间的显著差异？对于凝胶中两个相邻示踪剂的相关运动，也会提出类似的问题，这是一种通常用于双粒子微观流变学的装置。示踪剂的扩散特性将被量化的系综和时间平均粒子位移，非高斯性和非遍历性参数，以及相关性和概率分布函数的diffusingparticles。该项目的结果将为微观流变学实验的分析提供重要的输入，并允许在异质结构和弹性响应环境中颗粒扩散的物理化学性质的新见解，例如在生物细胞内，在多细胞组织中，在粘液膜中，或用于临床诊断工具的凝胶中。