photo credit: A 3D-printed nerve regeneration pathway in a test subject. University of Minnesota College of Science and Engineering
This innovation is not necessarily new; others have also attempted to 3D-print nerve guides. However, it is the culmination of these efforts that may eventually see its way to a hospital near you. If so, the treatment has the potential to aid more than 200,000 people a year who experience some sort of nerve injury or disease.
The process may be aptly suited for this field of medicine because nerves do not regenerate much after injury – if growth happens at all, it is usually slow and limited. Current treatment options include surgical procedures such as grafts or nerve guidance conduits, which are essentially tiny tubes that direct nerve endings toward each other.
This printing technology takes a slightly different approach: After 3D scanning a rat’s sciatic nerve, the researchers used a custom-built 3D printer to make silicone guides for nerve regeneration. These 3D-printed nerve pathways were embedded with biochemical cues to promote growth.
The final 3D-printed product was then implanted into rats with severed nerves. In about 10 to 12 weeks’ time, the rats experienced improved walking ability. The advantage of this technology is that precise shapes can be printed to suit the patient, rather than a one-tube-fits-all approach. The study is published in Advanced Functional Materials.
What sets this experiment apart, according to the researchers, is that it shows regrowth for a non-linear, complex nerve. The sciatic nerve is Y-shaped with both sensory and motor branches.
“This represents an important proof of concept of the 3D printing of custom nerve guides for the regeneration of complex nerve injuries,” said lead author Michael McAlpine, a professor of mechanical engineering at the University of Minnesota, in a statement.
One day in the future, he said, it may even be possible to make a “library” of scanned nerves from volunteers or cadavers to create close matches in situations where a nerve can’t be scanned.
McAlpine adds, “Someday we hope that we could have a 3D scanner and printer right at the hospital to create custom nerve guides right on site to restore nerve function.”