Exosomes are discrete populations of small (40-200 nm in diameter) membranous vesicles that are released into the extracellular space by most cell types, eventually accumulating in the circulation. As molecular messengers, exosomes exert a broad array of vital physiologic functions by transporting information between different cell types. Because of these functional properties, they may have potential as biomarker sources for prognostic and diagnostic disease. Recent research has found that exosomes have potential to be utilized as drug delivery agents for therapeutic targets. However, basic researches on exosomes and researches on their therapeutic potential both require the existence of effective and rapid methods for their separation from human samples. In the current absence of a standardized method, there are several methods available for the separation of exosomes, but very few studies have previously compared the efficiency and suitability of these different methods. Researchers from Nantong University summarize and compare the available traditional and novel methods for the extraction of exosomes from human samples and considered their advantages and disadvantages for use in clinical laboratories and point-of-care settings.
Schematic illustration of the ExoTIC device for exosomes isolation
Samples enter at a certain flow rate from the inlet, then the device rotates repeatedly. The sample is enriched in the complete exosomes in the size range of 30-200 nm through the nanoporous membrane. Free nucleic acids, proteins, lipids, and other small fragments were flushed out and concentrated exosomes were collected from a filter membrane using a standard pipette.