What are the biological characteristics of exosomes?

Exosomes have a few very distinct biological characteristics that make them unique and differentiate them from other extracellular vesicles. 

Size - Exosomes are tiny structures, typically ranging in size from 30 to 150 nanometers (nm). This small size allows them to travel through bodily fluids and cross various biological barriers more easily.

Origin - Endocytic in origin, exosomes are formed inside the cells within small compartments called endosomes. These endosomes then fuse with the cell's outer membrane, releasing the exosomes into the extracellular space.

Composition - Exosomes are composed of a lipid bilayer membrane, similar to the cell membrane, which encloses their contents. Each exosome carries a cargo of various molecules, including proteins, RNA (such as mRNA and microRNA), and lipids. The cargo composition can vary depending on the type of cells they originate from and their specific functions.

Stability – These are relatively stable structures, protected by their lipid membrane, which helps shield their cargo from degradation by enzymes and other factors in the extracellular environment.

Intercellular communication - Exosomes act as messengers between cells. They are involved in cell-to-cell communication by transferring their cargo molecules from the cells that release them to recipient cells. The type of cargo transferred can influence the behavior, function, and signaling pathways of the recipient cells.

Functionality - Exosomes have diverse functions in the body. They are involved in processes such as immune response, tissue repair, and development. They also play roles in diseases like cancer by potentially promoting tumor growth, metastasis, and immune evasion.