Single Particle Characterization and Isolation of Extracellular Vesicles

细胞外小泡(EV)是一种亚微米大小的生物颗粒，由细胞、细菌和酵母等所有生命形式分泌。电动汽车作为货物从它们被释放的细胞中携带分子(例如蛋白质、脂类、核酸)。它们可以反过来对摄取它们的细胞施加生物学效应，如诱导生长、增殖、迁移，甚至分泌可溶性生物活性因子。EVS在压力、损伤和疾病的情况下被释放，但也可以作为生物实体之间完成特定任务的一般通信手段被释放。单个电动汽车表面的蛋白质和标记将引导它们走向预期的目标细胞，然后这些细胞将吞噬它们。在细菌生物膜和生物液等复杂环境中，来自系统中所有细胞的EV被一起释放到细胞外环境中。由于电动汽车具有几乎相同的生物物理特性，目前的纯化方法将电动汽车作为一个整体进行分离。因此，研究EV的多样性或分离来自系统中特定细胞的EV几乎是不可能的。因此，人们对肠道病毒的多样性、亚群及其如何影响复杂和异质系统中受体细胞的行为知之甚少。

Extracellular vesicles (EVs) are submicron-sized biological particles secreted by all forms of life such as cells, bacteria and yeast. EVs carry as cargo molecules from the cells from which they were released (e.g., proteins, lipids, nucleic acids). These can in turn exert biological effects in cells that uptake them such as inducing growth, proliferation, migration and even the secretion of soluble bioactive factors. EVs are released in instances of stress, damage and disease, but can also be released as a means of general communication between biological entities to accomplish a specific task. Proteins and markers at the surface of individual EVs guide them towards their intended target cells that will then engulf them. In complex environments such as bacterial biofilms and biological fluids, EVs from all the cells in the system are released together into the extracellular environment. Because EVs share nearly identical biophysical properties, current purification methods isolate EVs as a bulk. It is therefore nearly impossible to study EV diversity or isolate EVs emanating from specific cells in the system. As such, very little is known about EV diversity, subpopulations and how they impact the behavior of recipient cells in complex and heterogeneous systems.