I. Overview of exosomes
Exosomes are a class of extracellular vesicles (EVs), generally ranging in diameter from 30 to 150nm. Extracellular vesicles are all kinds of vesicles with membrane structure released by cells. According to different sizes, synthesis methods and biological properties, extracellular vesicles are divided into a variety of different subtypes, exosomes being one of them.
The group most often compared to exosomes is another large group of extracellular vesicles, microparticles/microvesicles (hereafter referred to as microvesicles). The key difference between the two is the way they are synthesized. The microvesicles were produced by sprouting and the membrane structure was not very stable. Exosomes, on the other hand, first pass through the membrane invagination and finish the packaging process inside the cell before being released outside the cell. Therefore, exosomes have a more stable structure and can contain more abundant contents.
