Orthopaedic researchers at Wake Forest University Baptist Medical Center (WFUBMC) have been awarded a $2.24 million four-year grant from the U. S. Department of Defense (DOD) to study the use of keratin gel in the regeneration of damaged peripheral nerves, those in the hands, arms and feet.
Invented at the Institute for Regenerative Medicine at WFUBMC, keratin gel is a biomaterial derived from human hair. In pre-clinical testing at the Medical Center, keratin gel was shown to promote the growth of severed nerves by increasing the number of axons, the structures in the peripheral nervous system that carry signals to and from the spinal cord.
Almost 3 percent of patients who arrive at Level I trauma centers in this country have nerve injuries; treatment of these injuries costs an estimated $150 billion a year. Additionally, the DOD reports that among the most common injuries sustained by soldiers in Iraq and Afghanistan are blast and shrapnel wounds caused by improvised explosive devises, which produce extensive damage to skin, bones and nerves.
“Right now the standard treatment for severed nerves is to use a graft of the patient’s own nerve to repair the damaged one,” said Zhongyu Li, M.D., Ph.D., assistant professor at WFUBMC and principal investigator of the study. “In essence, you have to sacrifice a good nerve to fix the one that has been injured. When you do that, the patient loses some sensation in the nerve used for the graft, and the damaged nerve still may fail to repair itself and regain function.”
An alternative treatment to a graft is to use a nerve guidance conduit, a small tube, to bridge the gap between the severed nerve endings and support growth of the nerve, Li said. One of the limitations of this approach is that it can only be used to bridge a very small gap, usually less than 1/5 inch in width. “For a larger gap, neither a graft nor a tube works as well as desired,” he said.
In the Wake Forest Baptist study being funded by the DOD, researchers will test the use of the keratin gel inside nerve guidance conduits to determine if it improves nerve regeneration in patients. “An advantage to using keratin is that it is a natural human protein that is readily available and doesn’t cause any adverse immune response in the recipient,” Li said.
Pending approval by the U.S. Food and Drug Administration, a Phase 0 trial will determine the safety of the gel and be followed by a combined Phase I/II prospective randomized trial to follow patients who are treated with the keratin gel for traumatic peripheral nerve damage.
Volunteers enrolled in the study will be randomized to one of two treatment groups. The nerve injuries in one group will be treated with a conduit that will be used to bridge the gap in the injured nerve. The injuries in the other group also will be treated with a conduit, but the conduit will be filled with the keratin gel. These two groups will be followed for two years after their nerve repair surgeries to determine how well their injured nerves heal.
“Our goal is to encourage better regeneration of the nerves through the use of this gel, and hopefully improve results for both small and large nerve gaps in traumatic nerve injuries,” Li said.