Exosome-based therapies are an exciting development that were derived from research on how cells communicate with one another over distances within the body. Exosomes are nanosized structures within a cell that can be released, such as in response to an injury, and then taken up by nearby cells or enter the circulation where they can be delivered to other tissues or organs. Exosomes act as shuttles for certain genetic information and proteins to other cells that are important regulators in the body that tell different cells what to do and how and when to react. This cell-to-cell communication is critical in the body’s ability to maintain a healthy cellular environment. Exosomes play a key role in the regulation of these intercellular communication processes. Exosomes also offer the capacity to be engineered to express a label, be targeted to a selective cell type, or be loaded with specific cargo, such as pharmaceuticals for tissue or cell selective delivery.
The potential of this work is limitless as it relates to the repair of damaged cells in the spinal cord and other areas of the central nervous system. Damien D. Pearse, Ph.D., The John M. and Jocelyn H.K. Watkins Distinguished Chair in Cell Therapies, Professor, Department of Neurological Surgery and The Miami Project and his team in collaboration with researchers led by Ms. Aisha Khan from U. Miami Interdisciplinary Stem Cell Institute are investigating whether exosomes derived from Schwann cells and neural or mesenchymal stem cells have therapeutic benefit in neuroprotection and nerve regeneration. The goal is to transfer the valuable biological signals (exosomes) from the cells themselves and use them to protect neurons from dying or to direct nerves to regenerate after SCI.
“Exosomes, like the nano-sized vehicle of Fantastic Voyage, will allow us to deliver biomolecules or pharmaceuticals to specific areas of the body after injury to program damaged cells to survive and repair themselves,” said Dr. Pearse.
Dr. Pearse and his team hope to answer the fundamental questions about feasibility, delivery and effectiveness of using exosomes from distinct cell sources for SCI. Additionally, they hope to determine if these exosomes can provide beneficial actions for protection, repair and recovery that compare to the transplantation of the parent cell, whether Schwann cell or stem cell.
The current studies underway in Dr. Pearse’s lab hope to identify the most effective administration route for the delivery of cell-derived exosomes after SCI. This data will be compared with the more traditional transplantation of cells directly into the injured spinal cord to examine which technique proves more effective in repair and functional recovery following SCI.
These experiments will be performed in the same SCI paradigm to that Dr. Pearse and colleagues used in the initial Schwann Cell research endeavor, which is a clinically relevant cervical spinal cord injury model. If this therapy is proven effective, it may provide an alternative or complimentary approach to cellular transplantation, because exosomes are very small and can be delivered systemically, such as through a person’s vein. They can then travel to the injury site. This makes the therapy minimally invasive compared to a cell transplantation surgery.
Finally, the development of exosomes from our GMP human stem cells and Schwann cells will allow us to use the therapy for potential benefit in a wide range of diseases and conditions, from Multiple Sclerosis and Alzheimer’s disease to rheumatoid arthritis and traumatic brain injury based upon their anti-inflammatory and reparative properties.