THE ORIGIN AND PHENOTYPING OF EXTRACELLULAR VESICLES
Author: Nanofcm Date: November 25, 2021
Extracellular vesicles (EVs, 40~1,000 nm) are nanoscale membrane vesicles secreted by almost all cell types to mediate intercellular communication. EVs are typically divided into two sub-categories based on their biogenesiss. Large EVs (200~1,000 nm) are vesicles that pinch off the surface of the plasma membrane directly. Small EVs (40~200 nm) have an endosomal origin. Owing to their increasingly recognized functions in cellular homoeostasis, infection propagation, cancer development, cardiovascular diseases and immune response., these small vesicles have stimulated considerable scientific and clinical interest. In order to streamline the development of the EV field, the research community has established a set of rules describing best practices for every aspects of extracellular vesicle production, isolation, purification, and characterization. The guidelines, called, MISEV, are regularly updated to reflect constant developments in the knowledge of EVs.
In addition, EVs also opens new frontiers for modern therapies, which can be divided into two main categories: regenerative therapy by using EVs originated from mesenchymal stem cells (MSCs) and EV-based drug delivery systems. Since 2015, global revenues of EV-based diagnostics and therapies have increased rapidly. In 2016, Exosome Diagnostics Inc. launched the cancer diagnostic product ExoDx Prostate (IntelliScore) (EPI), the world’s first noninvasive liquid biopsy diagnostic conducted on EVs isolated from urine. However, the whole industry remains in its infancy, with no EV-based therapeutic agents currently available. Aegle Therapeutics (Woburn, US) announced the FDA has cleared its first Investigational New Drug (IND) application to initiate an EV clinical trial in severe second degree burn patients. For EV-based drug delivery, three products (exoIL-12, exoSTING and exoASO-STAT6) developed by Codiak Biosciences Inc. (Cambridge, US) have already received IND approval.