Exosomes are extracellular vesicles with a nanoparticle structure, 40-160 nm in diameter and a phospholipid bilayer. They are membrane vesicles that are released outside the cell by the fusion of intracellular multivesicular bodies with the cell membrane. There are a large number of membrane proteins in the cell membrane, which play an important role in the target binding process. The inclusions of exosomes also include RNA, mainly miRNA, accounting for about 80%, and Lnc RNA, etc.
詹姆斯·羅思曼(James E. Rathman)、蘭迪·謝克曼(Randy W. Schekman)、湯瑪士.居德霍夫(Thomas C. Südhof)這三位學者解開了「細胞如何組織其運輸系統」的奧秘,並揭示了細胞如何通過外泌體在適當的時間將貨物精確傳遞至正確位置的分子原理,開啟了外泌體在細胞通訊的研究新領域,三人因此在2013年獲得諾貝爾生理醫學獎的榮譽。因而學界開始發展各類外泌體於醫藥領域的相關研究及潛在的應用。