# Tarheel Health Portal/Spinal Cord Regeneration

Spinal Cord Injuries
Spinal cord injuries impact over 250,000 people throughout the United States with approximately 12,000 more injuries being added to this number every year. The main causes of Spinal cord injuries are car accidents, falls, and sport injuries. Each person in the United States is subject to this and have the possibility of suffering from these debilitating injuries. This includes students and faculty affiliated with the University of Chapel Hill. The symptoms and results of a Spinal cord injury depend on the location of injury and may include loss of motor and sensory function, difficulty breathing, arrhythmias, and circulatory issues. These severe symptoms are compounded by the inability of the spinal cord to heal itself naturally, making them essentially permenant. In the past, the only treatment has been physical therapy, which does not promise recovery of any function. However, researchers are working to solve the lack of regeneration and have made breakthroughs with different methods. One of these methods includes the transplantation of Schwann cells into the affected area of the spinal cord.

## The Schwann Cell

Schwann Cells are one type of glial cell that is found throughout the Peripheral nervous system, or PNS. Their purpose in a PNS cell is to ensure efficient transmission of cellular signals throughout the body by surrounding and insulating the axons found in neurons. While this is a Schwann Cells' typical function, they also participate in the regeneration and elongation of axons after an injury to the PNS. This is a critical reason that the neurons in the PNS have the ability to repair themselves and restore function after injury. However, the neurons in the Central nervous system, or CNS, do not have this same ability to regenerate after suffering an injury.

## Schwann Cell Transplantation

One of the most promising methods to regenerate the spinal cord is through the transplantation of the Schwann Cells discussed above. The process of transplantation of Schwann Cells into the cite of an injury is necessary due to the absence of these cells in the CNS as they are in the PNS. Schwann Cells are most easily obtained through tissues containing rapidly growing mesenchymal stem cells such as bone marrow tissue, umbilical cord tissue, and fat tissue. There have been numerous trials on rodents confirming the effectiveness of the transplantation of Schwann Cells.

### Polymer Scaffolding

A polymer scaffolding acts as a blueprint or a building block in the process of spinal cord regeneration. There are many different types and shapes of this scaffolding, but the general consensus has stated that the loading of Schwann Cells into a polymer scaffold, play a key role in successful spinal cord regeneration. The scaffold mimics the environment and structure where CNS neurons exist. This in turn facilitates the function of the Schwann Cells in filling and reconnecting the area that has been injured. The use of these polymer scaffolds is consistent in the ongoing research involving the use of Schwann Cells transplantation.

#### Regenerative Capabilities of Schwann Cells

This experiment was done in 2009 by Heather Olsen of the Mayo Clinic. She compared the regenerative capabilities of neural stem cells inserted into a scaffold, Schwann Cells inserted into a scaffold, and an empty scaffold. Her experiment took place over four weeks on rats that were inflicted with acute spinal cord injuries. At the end of the four weeks Olsen removed the scaffolds, that were initially transplanted, and used different methods to analyzed the amount of regrowth within the scaffold. In the Schwann Cell scaffolds, Olsen found up to 3000 regenerated axons. This was more than she found for the other two categories she analyzed. This is proof that Schwann Cell transplantation is an extremely viable method for the regeneration of a spinal cord after injury.

#### Schwann Cells and the Recovery of Motor Function

In 2002, T. Takami compared the capabilities of transplanted Schwann Cells to the capabilities of Olfactory ensheathing glia, which are also heavily researched in spinal cord regeneration. He inflicted rats with an acute spinal cord injury and treated them with scaffolds filled with three different solutions. One was a Schwann Cells only solution, another was olfactory ensheathing glia solution, and the last was a combination of both. Twelve weeks after the transplantation, he analyzed both the hindlimb motor functions of the rats compared to their initial function. Later he removed the scaffolds placed in the injury site and compared the regenerated volume of the axons to the initial volume recorded. He found that the Schwann Cell only solution resulted in the highest volume regeneration at 51% (compared to healthy spinal cord volume.) It was also found that the Schwann Cell only solution was the only solution that resulted in a significant recovery in motor function.

## The Miami Project to Cure Paralysis

The Miami Project to Cure Paralysis is a program, sponsored by the University of Miami, to find a cure for paralysis, a common symptom of spinal cord injuries. In January of 2013 the project began FDA approved clinical trials on humans using Schwann Cell transplantation. This was a breakthrough for the method of Schwann Cell transplantation to treat spinal cord injuries. The approval by the FDA signifies the beginning stages for this to become established as common practice in the medical field. This could potentially change the lives of many suffers of spinal cord injuries. If Schwann Cell transplantation is established in the medical field, the Neurosciences Hospital at the University of North Carolina could be taught to use this.

## Further Reading

* Full Article on the Schwann Cell Transplantation in Miami