Comparative electrokinetic properties of extracellular vesicles produced by yeast and bacteria

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 225; p. 113249
• Main Authors: Rogers, Nicholas M.K., McCumber, Alexander W., McMillan, Hannah M., McNamara, Ryan P., Dittmer, Dirk P., Kuehn, Meta J., Hendren, Christine Ogilvie, Wiesner, Mark R.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2023
• Subjects: Bacteria; Colloidal stability; Environmental fate; Extracellular vesicle; Extracellular Vesicles - chemistry; Saccharomyces cerevisiae; Surface potential; Yeast; Zeta potential; Yeast; Colloidal stability; Zeta potential; Environmental fate; Bacteria; Extracellular vesicle; Surface potential
• DOI: 10.1016/j.colsurfb.2023.113249
• ISSN: 0927-7765

Extracellular vesicles (EVs) are nano-sized, biocolloidal proteoliposomes that have been shown to be produced by all cell types studied to date and are ubiquitous in the environment. Extensive literature on colloidal particles has demonstrated the implications of surface chemistry on transport behavior. Hence, one may anticipate that physicochemical properties of EVs, particularly surface charge-associated properties, may influence EV transport and specificity of interactions with surfaces. Here we compare the surface chemistry of EVs as expressed by zeta potential (calculated from electrophoretic mobility measurements). The zeta potentials of EVs produced by Pseudomonas fluorescens, Staphylococcus aureus, and Saccharomyces cerevisiae were largely unaffected by changes in ionic strength and electrolyte type, but were affected by changes in pH. The addition of humic acid altered the calculated zeta potential of the EVs, especially for those from S. cerevisiae. Differences in zeta potential were compared between EVs and their respective parent cell with no consistent trend emerging; however, significant differences were discovered between the different cell types and their EVs. These findings imply that, while EV surface charge (as estimated from zeta potential) is relatively insensitive to the evaluated environmental conditions, EVs from different organisms can differ regarding which conditions will cause colloidal instability. [Display omitted] •EVs produced by Pseudomonas fluorescens, Staphylococcus aureus, and Saccharomyces cerevisiae.•EV zeta potential largely unaffected by changes in ionic strength/electrolyte type.•EV zeta potential affected by changes in pH.•S. cerevisiae EVs affected by presence of humic acid.•No consistent trend for relationship between EV and corresponding parent cell.