title: Size-dependent, stochastic nature of lipid exchange between nano-vesicles and model membranes.
abstract: The interaction of nanoscale lipid vesicles with cell membranes is of fundamental importance for the design and development of vesicular drug delivery systems. Here, we introduce a novel approach to study vesicle-membrane interactions whereby we are able to probe the influence of nanoscale membrane properties on the dynamic adsorption, exchange, and detachment of vesicles. Using total internal reflection fluorescence (TIRF) microscopy, we monitor these processes in real-time upon the electrostatically tuned attachment of individual, sub-100 nm vesicles to a supported lipid bilayer. The observed exponential vesicle detachment rate depends strongly on the vesicle size, but not on the vesicle charge, which suggests that lipid exchange occurs during a single stochastic event, which is consistent with membrane stalk formation. The fluorescence microscopy assay developed in this work may enable measuring of the probability of stalk formation in a controlled manner, which is of fundamental importance in membrane biology, offering a new tool to understand nanoscale phenomena in the context of biological sciences.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore. njcho@ntu.edu.sg.
authors.forename: Seyed R
authors.initials: SR
authors.lastname: Tabaei
authors.forename: Jurriaan J J
authors.initials: JJ
authors.lastname: Gillissen
authors.forename: Setareh
authors.initials: S
authors.lastname: Vafaei
authors.forename: Jay T
authors.initials: JT
authors.lastname: Groves
authors.forename: Nam-Joon
authors.initials: NJ
authors.lastname: Cho