Exosomes in regenerative medicine are nano-sized biovesicles released into body fluids through the fusion of multivesicular bodies and the plasma membrane.
These vesicles carry cell-specific cargo—including proteins, lipids, and genetic materials—and can be selectively absorbed by nearby or distant cells. Once received, their bioactive compounds may reprogram the recipient cells.
Because of this, the formation of exosomes, their targeted cargo, and their specificity are of high biological interest. The potential of exosomes in regenerative medicine includes their use as non-invasive diagnostic biomarkers and as therapeutic nanocarriers.
The exosomes are also called intraluminal vesicles and are found in various tissues and body fluids (5-7). Expand
Sourcing and safety*
The exosomes derived from mesenchymal stem cells (MSCs) are of prime importance due to the greater therapeutic and regenerative potential as shown in Figure 4. Due to the challenges faced in isolating exosomes from various body fluids, regenerative and translational medicine experts used MSC-derived exosomes for treating various disorders (2). MSCs derived exosomal cargo exhibit intracellular signaling and communications to targeted tissues. The key sources of exosomes derived from the MSCs include bone marrow, adipose tissue, placental cells, umbilical cells, endometrial fluid, and amniotic fluid (2, 100 ).
Exosomes of MSC origin have cell surface markers such as CD 29, CD 44, and CD 73 embedded in them (100). They play a vital role in the biomechanisms involved in the repair and regeneration, bioenergetics, immunoregulation, intracellular communication, and tissue metabolism (2, 101 ). In a proteomic analysis, a total of 730 protein molecules in bone marrow MSC derived exosomes were isolated (102). Some researchers found the existence of transcription signaling factors in exosomal cargoes (103). Amniotic fluid exosomes are the most preferred exosomes for clinical applications than bone marrow-derived exosomes (104).
References
Wang K, Jiang Z, Webster KA, et al. Enhanced Cardioprotection by Human Endometrium Mesenchymal Stem Cells Driven by Exosomal MicroRNA-21. Stem Cells Transl Med 2017;6:209- 22. 10.5966/sctm.2015-0386 [PMC free article] [PubMed] [ CrossRef ] [Google Scholar]
101. Lou G, Chen Z, Zheng M, et al. Mesenchymal stem cell-derived exosomes as a new therapeutic strategy for liver diseases. Exp Mol Med 2017;49:e346. 10.1038/emm.2017.63 [PMC free article] [PubMed] [ CrossRef ] [Google Scholar]
102. Kim HS, Choi DY, Yun SJ, et al. Proteomic analysis of microvesicles derived from human mesenchymal stem cells. J Proteome Res 2012;11:839-49. 10.1021/pr200682z [PubMed] [ CrossRef ] [Google Scholar]
103. Merino-González C, Zuñiga FA, Escudero C, et al. Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Angiogenesis: Potential Clinical Application. Front Physiol 2016;7:24. 10.3389/fphys.2016.00024 [PMC free article] [PubMed] [ CrossRef ] [Google Scholar]
104. Tracy SA, Ahmed A, Tigges JC, et al. A comparison of clinically relevant sources of mesenchymal stem cell-derived exosomes: Bone marrow and amniotic fluid. J Pediatr Surg 2019;54:86-90. 10.1016/j.jpedsurg.2018.10.020 [PubMed] [ CrossRef ] [Google Scholar]