Forms of stem cell therapy, such as those using mesenchymal stem cells, are now fairly common. They are unreliable when it comes to spurring regeneration, the original goal, but they do well when it comes to reducing chronic inflammation in the context of age-related conditions. Working with cells is, however, comparatively costly and comes with a number of logistical issues regarding production, quality, storage, transport, and so forth.
Since this type of cell therapy likely achieves the majority of its beneficial effects via the signaling produced by transplanted cells in the short period of time before they die, academia and industry is ever more focused on reproducing that signaling without the need for cells. Exosomes are membrane-bound packages of signal molecules secreted by cells, and one of the primary means by which stem cells affect the behavior of surrounding cells. Once harvested from stem cells in culture, exosomes are much easier to store and use in therapy than is the case for the cells themselves, while still appearing to deliver similar benefits in the context of first generation stem cell therapies.
Exosomes harvested from mesenchymal stem cells (MSCs-Exo), as a treatment for diseases, has better safety and convenience compared with stem cell therapy, and will certainly play a huge role in the future clinical treatment of diseases. Exosomes as the carrier of therapy can be applied to a variety of diseases, to achieve the effect that conventional therapy cannot achieve. As biologically active nano-vesicles, MSCs-Exo have shown many advantages in disease treatment, such as cardiovascular disease, neurodegenerative disease, tumors, and regenerative medicine.
Currently, an accumulating amount of evidence has been showing that MSCs-Exo has disease treating potential and can successfully apply for the therapy of several kinds of disease. A few clinical trials are currently on-going but there are still challenges to overcome for further clinical translation such as the scale-up of the production, the lack of standardization for isolation and characterization methods and the low encapsulation efficiency. In contrast with MSCs, evidence suggests that MSCs-Exo promotes angiogenesis, restrains inflammatory effects, decreases immunogenicity, and reduces tumor production.
As a therapeutic tool, compared with standard delivery methods, MSCs-Exo holds great therapeutic promise, but still faces many challenges. Due to the size and complexity of MSCs-Exo, there are challenges in clinical practice, such as large-scale pharmaceutical production and production costs. Previously, scientists used ultracentrifugation to purify exosomes, which was a labor-intensive and time-consuming process that could not be used for large-scale production. The focus of future research is to find new solutions in future research and develop a simple purification method with very low cost and safety.