Regenerative medicine using stem cells is an increasingly promising approach to treat many types of injury. Transplanted stem cells can differentiate into just about any other kind of cell, including neurons to potentially reconnect a severed spinal cord and repair paralysis. A variety of agents have been shown to induce transplanted stem cells to differentiate into neurons. Tufts University biomedical engineers recently published the first report of a promising new way to induce human mesenchymal stem cells (hMSCs) (see image), which are derived from bone marrow, to differentiate into neuron-like cells. That new way is treating the hMSCs with exosomes. Exosomes are very small, essentially hollow (although often filled with all sorts of biomolecules) vesicles that are secreted from virtually every, if not every, type of cell. Exosomes can contain functional proteins and genetic materials and can serve as vehicles for communication between cells. In the nervous system, exosomes are known to guide the direction of nerve growth, control nerve connection, and help regenerate peripheral nerves. In a series of experiments reported online on August 6, 2015 in an open-access article in PLOS ONE, the Tufts researchers showed that exosomes from PC12 cells (neuron-like progenitor cells derived from rats) at various stages of their own differentiation could, in turn, cause hMSCs to become neuron-like cells. Exosomes had not previously been studied as a way to induce human stem cell differentiation.Login Or Register To Read Full Story