What are Exosomes?
Exosomes are messenger particles that release naturally from a cell. These particles are responsible for cell to cell communication. Exosomes carry genetic information and proteins to cells throughout your body, and they create paths for communication between cells. These messenger cells have the ability to release growth factors and other beneficial processes. Also known as are extracellular vesicles (particles that release naturally from a cell that cannot replicate) that are responsible for cell to cell communication. Exosomes are released naturally from cells upon the fusion of a discontinuous closed membrane system, also known as the intermediate endocytic compartment. Although exosomes are roughly the same size (40-100 nm) as ectosomes, they are different species of vesicles.
According to a 2019 study published in the Cell and Bioscience Journal, Exosomes are nano-sized biovesicles released into surrounding body fluids upon fusion of multivesicular bodies and the plasma membrane. They were shown to carry cell-specific cargos of proteins, lipids, and genetic materials, and can be selectively taken up by neighboring or distant cells far from their release, reprogramming the recipient cells upon their bioactive compounds. (3)
What is exosome therapy?
Exosome therapy is gaining in popularity within the United States. Some doctors believe there may be benefits with the administration of exosomes, but there is minimal data proving safety and efficacy. This theory may have originated from studies that suggest the link between the health benefits of mesenchymal stem cells and exosomes. Exosomes are released naturally from mesenchymal stem cells, and MSCs have the highest amount of exosomes out of any cell. These studies (outlined below) argue that exosomes may have therapeutic abilities, but researchers have found no conclusive evidence. There is also a regulatory concern about the legality of such treatments, especially when the exosome preparation protocol involves extraction from MSCs.
Why the increased interest in Exosome therapy?
According to a 2016 study conducted James R Edgar and colleagues, we could be seeing an increased interest for Exosome therapy for a few reasons:
- Exosomes are thought to provide a means of intercellular communication and transmission of macromolecules between cells
- Exosomes have been attributed roles in the spread of proteins, lipids, mRNA, miRNA, and DNA and as contributing factors in the development of several diseases
- Exosomes have been proposed to be useful vectors for drugs because they are composed of cell membranes rather than synthetic polymers, and as such, could be better tolerated by the host
Unlike stem cell therapy, exosome therapy doesn’t involve using donor cells in your body. Instead, exosomes are extracted from donated human mesenchymal stem cells (MSCs). The exosome solution contains valuable lipids, messenger-RNA, micro-RNA, signaling cytokines, and proteins. Exosome therapy can be administered through intravenous (IV) therapy or direct injection in the treatment area.
Exosomes and stem cells
Mesenchymal stem cells (MSCs) can self-renew and can be isolated from various tissues. They have been tested widely in clinical trials due to their multitude of biological functions, including; differentiation, tissue repair, anti-inflammatory, and immunomodulatory properties. Exosomes derived from mesenchymal stem cells (MSCs), first investigated in a 2010 finding, showed that MSCs were able to produce higher amounts of exosomes than other cells. (2)
According to Zhang, exosomes are involved in cell to cell communication, and some researchers hypothesize that they are the paracrine effectors of MSCs. Many types of cells secrete exosomes, including T and B cells, cancer cells, and stem cells. Although Exosomes are essential for cellular communication, their functions remain unknown.
Mesenchymal Stem Cells naturally secrete Exosomes
Mesenchymal stem cells may have the ability to repair tissue, modulate the immune system, and promote an anti-inflammatory response in patients. In an article published in the International Journal of Molecular Sciences, Zhang et al. state that “Several studies have reported that exosomes have functions similar to MSCs; however, the mechanisms are still not fully understood and remain controversial.” (2)
“Given the merits of MSCs, exosomes hold great promise as a controllable, manageable, and feasible approach in future studies. However, based on the proteomic and genomic complexities of exosomes, their possible mechanisms and exact compositions need further investigation.” Mesenchymal stem cells can produce prolific amounts of exosomes. Exosomes derived from mesenchymal stem cells have the potential to be used as a vehicle for drug or gene delivery or to facilitate cell therapy. (2) The study concluded that exosomes hold promise, but more studies are required before being able to consider using exosomes alone as a potential treatment option.
Exosomes therapies for anti-aging
Clinics in the United States are hailing exosome therapy for anti-aging as a new miracle cure. Some of these entities state that exosomes are more potent than MSCs at combating certain conditions. There are a few issues with these claims; firstly, there is a lack of data supporting the efficacy of exosomes without also introducing MSCs into the patient. Secondly, there are regulation concerns with exosomes in the United States that may promote the use of exosomes as a way of offering cell therapy while avoiding legal limitations set forth from the FDA. While there could potentially be some benefits with exosomes, they are still mostly understudied and unknown.
Exosome therapy and the FDA
Treatment with expanded MSCs is primarily not authorized by the FDA in the United States. These cells require approval from the FDA and require an Investigational New Drug Application (IND) submission. These regulations directly correlate with the rise in the popularity of exosome therapies. The regulatory environment in the United States and the disparity between different therapeutics can benefit clinics that market and administer exosomes because it may be easier to bypass the 4th criterion of 361 HCT/P’ S.
Exosome therapy may eventually have a place in the regenerative medicine sphere, but for now, it seems as though the development of using exosomes for treatment is still in its early stages. It is vital to have reliable data from clinical studies in human subjects that can prove that these exosome products functionally work.
(1) Edgar, James R. “Q&A: What Are Exosomes, Exactly?” BMC Biology, BioMed Central, 13 June 2016, https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0268-z.
(2) Yu, Bo, et al. “Exosomes Derived from Mesenchymal Stem Cells.” International Journal of Molecular Sciences, vol. 15, no. 3, July 2014, pp. 4142–4157., doi:10.3390/ijms15034142.
(3) Zhang, Y., Liu, Y., Liu, H., & Tang, W. H. (2019, February 15). Exosomes: Biogenesis, biologic function and clinical potential - cell & bioscience. BioMed Central. Retrieved February 3, 2022, from https://cellandbioscience.biomedcentral.com/articles/10.1186/s13578-019-0282-2
Note: This post is intended to provide general information about regenerative medicine, and related areas. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if a treatment is right for you.
About the author
Louis A. Cona, MD
Medical Director | DVC Stem
Dr. Cona has been performing stem cell therapy for over 12 years. He is a member of the World Academy of Anti-Aging Medicine (WAAAM). He is also a recognized member of the British Medical Association, the General Medical Council (UK), the Caribbean College of Family Physicians, and the American Academy of Family Physicians. He is the Medical Director for DVC Stem a world-renowned stem cell therapy clinic located in Grand Cayman.