Exosomes are a type of extracellular vesicle that contain constituents (like protein, DNA, and RNA) of the cells that secrete them. They are taken up by distant cells, where they can affect cell function and behavior.

Exosomes are vesicles, or cellular components, that exist outside of a cell. They are generally understood as having been released from cells upon fusion with an intermediate endocytic compartment, or a multivesicular body (MVB).

When the MVB fuses with the plasma membrane surrounding the cell, intraluminal vesicles are released into the extracellular matrix and become exosomes. Other types of vesicles found outside of cells include apoptotic bodies and exosomes. These are distinct types of vesicles from the exosome.

Due to the above-mentioned factors, the Global Exosome Research Market is growing at a lot faster pace. According to a research report by Astute Analytica, the global Exosome Research Market will register a CAGR (Compound Annual Growth Rate) of 24.4% over the forecast period of 2023-2031.

Generation of Exomes 

Multivesicular bodies are a specialized subset of endosomes that contain membrane-bound intraluminal vesicles. Intraluminal vesicles are essentially the precursors of exosomes and form by budding into the lumen of the multivesicular body.

Most intraluminal vesicles fuse with lysosomes for subsequent degradation, while others are released into the extracellular space. The intraluminal vesicles that are secreted into the extracellular space become exosomes. This release occurs when the multivesicular body fuses with the plasma membrane.

Use of Exomes in Diagnostics 

Exosomes can function as potential biomarkers, as their contents are molecular signatures of their originating cells. Due to the lipid bilayer, exosome contents are relatively stable and protected against external proteases and other enzymes.

Consequently, exosome-based diagnostic tests are being pursued in the early detection of cancer, diabetes, and other diseases. Many exosome proteins, nucleic acids, and lipids are being explored as potential clinically relevant biomarkers.

Exosomes are also highly accessible as they are present in a wide array of biofluids (including blood, urine, saliva, tears, ascites, semen, colostrum, breast milk, amniotic fluid, and cerebrospinal fluid), creating many opportunities for liquid biopsies. 

Therapeutic applications of exosomes 

Different approaches to creating drug-loaded exosomes include: 

• incorporating a drug into exosomes that have been purified from donor cells, 

• loading cells with a drug that is then contained within exosomes, 

• transfecting cells with DNA encoding therapeutically-active compounds that are then contained within exosomes. 

Exosomes hold huge potential as a way to complement chimeric antigen receptor T (CAR-T) cells in attacking cancer cells. CAR exosomes, which are released from CAR-T cells, carry CAR on their surface and express a high level of cytotoxic molecules and inhibit tumor growth. Cancer cell-derived exosomes carrying associated antigens have also been shown to recruit an antitumor immune response.