Abstract: Objective To explore the current research, core mechanisms, opportunities, and challenges related to mesenchymal stem cell-derived exosomes in disease treatment, and to provide references for their subsequent clinical translation. Methods PubMed was searched for related literature by using mesenchymal stem cell and exosome as key words. Articles published within the past ten years and those published earlier were included to summarize the research findings and applications associated with the discovery, components and functional mechanisms of mesenchymal stem cell-derived exosomes. Challenges facing the clinical translation of mesenchymal stem cell-derived exosomes were discussed. Results Exosomes were the crucial mediator of functions of mesenchymal stem cells and could be potentially used for the treatment of diseases. Exosomes enjoyed advantages over mesenchymal stem cells in quality control and safety assessment due to their simpler structure and lower immunogenicity. In addition, mesenchymal stem cell-derived exosomes were nanoscale in size, making it possible for them to cross the blood-brain barrier. These exosomes promised to be a sphere of study that was capable of easy translation. Conclusion Mesenchymal stem cell-derived exosomes are one of the hot spots for regenerative medicine and rapid progress is being made in basic research and clinical translation. There is evidence that exosomes are lower in immunogenicity, stronger in tissue penetration and higher in targeting potential compared with mesenchymal stem cell therapies, which makes mesenchymal stem cell-derived exosomes superior to traditional stem cell therapies. The cell-free therapy strategy generated herein can possibly provide a new line of thought for research into stem cell therapies.

Key words: Mesenchymal Stem Cell, Exosome, Immunogenicity, Target, Stem Cell Therapies, Pharmacological Mechanisms, Clinical Application