[Typical strategy and research progress of efficient isolation methods of exosomes based on affinity interaction]

Exosomes form a subclass of extracellular vesicle that are secreted by most cells and found in nearly all body fluids, including blood, urine, saliva, amniotic fluid, and milk, as well as in various tissues and intercellular spaces. Exosomes have recently been recognized as crucial intercellular communication mediators, and an increasing number of studies have shown that exosomes are important liquid-biopsy tools that play irreplaceable roles in the diagnosis, prognosis, and treatment of diseases. The ability to isolate high-quality exosomes is a prerequisite for diagnosing and subsequently treating diseases in an accurate and repeatable manner. However, efficiently isolating exosomes from complex biological samples is challenging owing to their relatively low abundances and interference from non-vesicular macromolecules (such as cell debris and proteins). To date, various isolation techniques based on the physical, chemical, and biological characteristics of exosomes have been developed. Indeed, efficient affinity-interaction-based methods have recently overcome the limitations and drawbacks of traditional exosome isolation methods and are widely used in scientific research and clinical applications. This review focuses on exosome isolation and enrichment, and systematically reviews recent research progress on efficient isolation methods based on affinity interactions. Developmental prospects of exosome isolation and enrichment directions are analyzed with the aim of providing a reference for the construction and use of new exosome-isolation strategies.