A protein found in human hair shows promise for promoting the regeneration of nerve tissue and could lead to a new treatment option when nerves are cut or crushed from trauma.
In the current issue of Biomaterials, scientists from Wake Forest University School of Medicine reported that in animal studies the protein keratin was able to speed up nerve regeneration and improve nerve function compared to current treatment options.
“We found that the nerve repair happened more quickly and consistently, and that functional recovery was higher,” said Mark Van Dyke, Ph.D., senior author and an assistant professor of regenerative medicine. “The fact that we were able to accomplish this with gels made from keratin is pretty remarkable.”
Current treatments for repairing damaged nerves include microsurgery to sew two ends of the nerve together, using a nerve from another part of the body to replace a damaged section, or placing an empty tube between the cut ends so that nerve fibers can grow through it and back into the muscle.
Grafting a nerve from another part of the body is usually the most effective option, but it creates another injury site and isn't possible in all patients. The tubes, known as nerve guidance conduits, cannot be used in gaps longer than three or four centimeters. In addition, nerve regeneration with this method is not always successful. For example, after about age 17, nerves don't regenerate as well.
Laboratory scientists have tried placing natural materials, such as collagen, into the conduits to promote nerve regeneration. Van Dyke's team was the first to use keratin, which is believed to contain molecules that regulate cell behavior.
The scientists collected human hair from a local barber shop and chemically processed it to remove the keratin. They purified the keratin protein and used it to form gels that were then used to fill the nerve guidance conduits. They studied how keratin affects the activity of Schwann cells, which play a vital role in nerve regeneration. These cells produce signals that tell nerve cells to begin regenerating and “remodel” the blood clot that has formed so that nerve cells can grow across it.
“By using keratin to activate these cells, we're trying to tap into the natural healing cascade,” said Van Dyke. “We believe that keratin helps amp up Schwann cell activity and give the nerve regeneration process a head start.”