커피링 효과를 이용한 세포 밖 소포 분리

Abstract

Extracellular vesicles have numerous functions, and are categorized in subpopulations, such as exosomes or microvesicles according to their biogenesis processes. However, no decisive biological marker currently exists to distinguish exosomes from microvesicles, and the possible distinction between them is attributed to differences in physical properties. Here, the new chromatography method was developed with ~48 nm resolution that exploits Marangoni flow and the coffee-ring effect in microdroplets to separate EVs spatially based on particle size. Also, a sequential droplet transfer process was introduced that isolates larger EVs by repeating the serial steps of coffee-ring formation and consequently allows downstream RNA and protein analysis based on size. Results obtained by this method indicate that the size of EVs is correlated with expression levels of certain tetraspanin proteins that are associated with cell membranes. Additional results from EVs taken from prostate cancer patients indicate that smaller EVs from plasma of prostate cancer patients show higher cancer-associated gene and protein expression than larger EVs. The totality of the evidence shows that sorting EVs based on size is important for analyzing subpopulation EVs, and the methods described, i.e., chromatography performed using a combination of coffee ring effect with Marangoni flow and sequential droplet transfer, allow analysis of subpopulations of EVs, contributing to further studies of EVs.