Quantitative Analysis of Cargo Density in Single-extracellular Vesicles by Imaging

Area of Science:

• Biochemistry
• Cell Biology
• Nanotechnology

Background:

• Extracellular vesicles (EVs), including exosomes and microvesicles, play crucial roles in intercellular communication.
• The function of EVs is dictated by their diverse internal cargoes, which exhibit significant heterogeneity even within purified EV populations.
• Understanding this cargo heterogeneity is essential for deciphering EV function and their involvement in physiological and pathological processes.

Purpose of the Study:

• To develop and present a novel method for quantifying cargo density at the single-extracellular vesicle level.
• To provide a tool for detailed analysis of cargo heterogeneity within extracellular vesicle populations.
• To enable the study of factors influencing cargo sorting and EV composition.

Main Methods:

• Extracellular vesicles were stained in a manner proportionate to their membrane lipid content.
• Extracellular vesicles were immobilized onto a glass substrate for analysis.
• The developed protocol allows for the quantification of cargo density in individual extracellular vesicles.

Main Results:

• A new method was successfully established to measure cargo density in single extracellular vesicles.
• The protocol enables the characterization of cargo heterogeneity at the single-vesicle level.
• This technique provides quantitative data on the cargo content of individual EVs.

Conclusions:

• The described method offers a valuable approach to quantify cargo density in single extracellular vesicles.
• This protocol can be instrumental in investigating the impact of drugs or genetic modifications on EV cargo sorting.
• The findings contribute to a deeper understanding of extracellular vesicle heterogeneity and biogenesis.