A smile speaks volumes in human communication, but for those with facial nerve injuries, this simple gesture can become impossible. Now, University of Pittsburgh bioengineers have developed an innovative solution using stem cells that could transform how we treat these devastating injuries.
Published in Journal of Neural Engineering | Estimated reading time: 5 minutes
Traditional treatments for facial nerve injuries rely on autografts – nerve tissue taken from elsewhere in the patient’s body. While this approach has been the standard, it comes with significant drawbacks: donor site damage and roughly 50-50 odds of successful recovery. But nature’s master engineers – stem cells – might offer a better way forward.
A research team led by Dr. Fatima Syed-Picard, professor of oral and craniofacial sciences and bioengineering, has engineered implantable conduits that serve as bridges for injured nerves. As she explains, “We leaned into the idea that the cells know what they’re doing, and they know how to make tissue.”
The innovation lies in letting dental pulp stem cells (DPSCs) create their own tissue scaffolding. These cells, harvested from wisdom teeth, naturally produce proteins that encourage nerve growth. The researchers guided these cells to create aligned extracellular matrix (ECM) using specially designed rubber molds with microscopic grooves.
The results were remarkable. In experiments with rats, the stem cell-created conduits performed as well as traditional autografts in repairing facial nerve gaps. The team specifically focused on the buccal branch – the nerve responsible for smiling. As lead author Michelle Drewry, Ph.D., points out, “It’s a big part of your quality of life because it’s a large piece of how you communicate with other people and how you’re seen in the world.”
Twelve weeks after implantation, the conduits showed robust axon regeneration across their entire length, matching the performance of autografts. Even more encouraging, the whisker movement tests in rats showed equivalent functional recovery between the two approaches.
Glossary
- Autograft: Tissue taken from one part of a patient’s body to repair another part, currently the standard treatment for nerve injuries
- Dental Pulp Stem Cells (DPSCs): Adult stem cells found in teeth that can produce proteins supporting nerve growth and tissue regeneration
- Axons: Long projections extending from nerve cells that need to both regrow and reconnect properly for successful nerve repair
Test Your Knowledge
What is the current standard treatment for facial nerve injuries?
Autografts – nerve tissue taken from elsewhere in the patient’s body.
What type of stem cells did the researchers use in their new treatment?
Dental pulp stem cells (DPSCs) extracted from wisdom teeth.
How large were the nerve gaps that the engineered conduits successfully bridged?
The conduits bridged 5-millimeter gaps, which are too large for natural healing to occur.
What makes this new approach potentially better than synthetic alternatives that have been tried before?
The stem cells create their own supportive environment and aligned extracellular matrix, making the tissue more biomimetic than synthetically derived scaffolds.