Mesenchymal Stem Cell Exosomes
Exosomes are extracellular vesicles ranging between 30-150 nm that are produced by virtually every cell type as a means of intercellular communication They contain proteins (growth factors), mRNA (blueprint for protein production) and micro RNA (on a switch for specific protein production), all contained within a membrane similar to their parent cells that protects exosomal proteins and RNA from degradation until they are delivered to the target cell.
MSC exosomes are very different than exosomes found in adult bone marrow, which has a preponderance of hematopoietic stem cell exosomes, or amniotic fluid, which has primarily maternal epithelial cell exosomes. The distinct ability of MSC exosomes to induce connective tissue synthesis may be the basis of many of the remarkable clinical benefits that have been observed with stem cell therapy.
As we age, the number and function of the MSCs in our tissues declines sharply. Aged autologous progenitor cells produce about 30% of the cytokines and significantly different miRNAs compared with perinatal MSCs. This substantial difference in secretome confers a significant advantage of perinatal MSC exosomes over exosomes from aged autologous or allogeneic progenitor cells.