Abstract:
Bacterial membrane vesicles (BMVs) are extracellular vesicles secreted by either Gram-positive or Gram-negative bacteria. These BMVs typically possess a diameter between 20 and 250 nm. Due to their size, when these BMVs are suspended in another medium, they could be constituents of a colloidal system. It has been hypothesized that investigating BMVs as colloidal particles could help characterize BMV interactions with other environmentally relevant surfaces. Developing a more thorough understanding of BMV interactions with other surfaces would be critical for developing predictive models of their environmental fate. However, this bio-colloidal perspective has been largely overlooked for BMVs, despite the wealth of methods and expertise available to characterize colloidal particles. A particular strength of taking a more colloid-centric approach to BMV characterization is the potential to quantify a particle\'s attachment efficiency (α). These values describe the likelihood of attachment during particle-particle or particle-surface interactions, especially those interactions which are governed by physicochemical interactions (such as those described by DLVO and xDLVO theory). Elucidating the influence of physical and electrochemical properties on these attachment efficiency values could give insights into the primary factors driving interactions between BMVs and other surfaces. This chapter details methods for the characterization of BMVs as colloids, beginning with size and surface charge (i.e., electrophoretic mobility/zeta potential) measurements. Afterward, this chapter will address experimental design, especially column experiments, targeted for BMV investigation and the determination of α values.
摘要:
细菌膜囊泡(BMV)是由革兰氏阳性或革兰氏阴性细菌分泌的细胞外囊泡。这些BMV通常具有介于20和250nm之间的直径。由于它们的大小,当这些BMV悬浮在另一种培养基中时,它们可能是胶体系统的组成部分。已经假设研究BMV作为胶体颗粒可以帮助表征BMV与其他环境相关表面的相互作用。对BMV与其他表面的相互作用进行更透彻的了解对于开发其环境命运的预测模型至关重要。然而,这种生物胶体的观点在很大程度上被忽视了,尽管有丰富的方法和专业知识来表征胶体颗粒。采取以胶体为中心的方法进行BMV表征的特殊优势是量化颗粒附着效率(α)的潜力。这些值描述了在粒子-粒子或粒子-表面相互作用期间附着的可能性,特别是那些受物理化学相互作用控制的相互作用(例如DLVO和xDLVO理论描述的那些)。阐明物理和电化学性质对这些附着效率值的影响可以洞悉驱动BMV和其他表面之间相互作用的主要因素。本章详细介绍了将BMV表征为胶体的方法,从尺寸和表面电荷开始(即,电泳迁移率/ζ电位)测量。之后,本章将讨论实验设计,尤其是柱实验,针对BMV调查和α值的测定。