Faced with repairing a major nerve injury to the craniofacial region, surgeons can use a nerve from an arm or leg to restore movement or sensation. This approach—known as an autograft—is the standard of care, but it can take a toll on a previously uninjured body part, and the procedure doesn’t always result in complete and functional nerve regrowth. Dr. Anh Le, Chair and Norman Vine Endowed Professor of Oral Rehabilitation in the Department of Oral and Maxillofacial Surgery at Penn Dental Medicine, is pioneering a different approach.
Le and collaborators are coaxing gingival mesenchymal stem cells (GMSCs)—stem cells from gum tissue—to produce nerve-supportive cells that facilitate nerve regrowth.
“We wanted to create a biological approach and use the regenerating ability of stem cells,” said Le. “To be able to recreate nerve-supportive cells in this way is really a new paradigm.”
For more than a decade, Le’s lab has explored the use of GMSCs to regenerate different types of craniofacial tissues and to treat osteonecrosis of the jaw, which can occur when a patient takes bisphosphonate, a drug used to treat metastatic cancer or prevent bone loss in osteoporosis. Her lab team was able to apply their previous understanding of GMSCs to facilitate their conversion into Schwann-like cells, the pro-regenerative cells of the peripheral nervous system that make neural growth factors and myelin, the insulating layer around nerves.
To move the work forward, Le collaborated with bioengineer D. Kacy Cullen of Penn Medicine, an expert in creating and testing nerve scaffold materials. Together they showed that infusing a collagen scaffold with these cells and using them to guide the repair of facial nerve injuries in animals was just as effective as an autograft procedure. Although the repaired gap was small, the team is continuing to refine the method to repair larger ones that often result from trauma or tumor-removal surgeries.
Le notes that this approach would enable patients with oral cancer or facial trauma to use their own tissue to recover motor function and sensation following a repair.
While Le’s group focuses on the head and neck, further work on this model could translate to nerve repair in other areas of the body as well.
“I’m hopeful we can continue moving this forward toward clinical application,” she said.
