Research on Activity-Based Treatments to Accelerate Peripheral Axon Regeneration Finds Notable Results

Published July 05, 2024

Development Grants

Colin Franz, MD, PhD, a physician-scientist, director of the EDX laboratory at the Shirley RyanAbilityLab Hospital (primary), and assistant professor of PM&R and neurology at Northwestern University Feinberg School of Medicine in Chicago, Illinois, completed his ANF Development Grant-funded research titled, "Activity-Based Treatments to Accelerate Peripheral Axon Regeneration." It aimed to address the critical lack of FDA-approved treatments that have been proven to accelerate the process of axon regeneration using therapeutic electrical stimulation. 

"Our team learned that our recently developed wireless, battery-free, fully implantable peripheral nerve interface made from advanced materials, which allow the implant to naturally degrade over hours to weeks (depending on materials chosen), was able to effectively deliver therapeutic electrical stimulation to regenerating axons in a fashion that compares to conventional percutaneous wire-based nerve stimulator approach," Dr. Franz explained.

The team continued their efforts through therapeutic electrical stimulation with their new device, which showed promise through effective improvement in rodent sciatic nerve regeneration after a single one-hour session. They also created a longer-lasting device that could deliver daily, one-hour sessions of therapeutic electrical stimulation. They found it to have even greater efficacy and believe it will help scale up the therapy dose to go from rodents to human studies in the future.

One of the study's surprises was the extended operational life of the device. "We had hoped to achieve 14 days of operability before the device began to gradually bio-resorb in the body. However, we achieved over two months of operating life in our latest versions," Dr. Franz noted. This longevity suggests the technology could be scalable for clinical nerve repair, often requiring extended periods for axonal growth and muscle reinnervation.

The research successfully developed and demonstrated the effectiveness of new therapeutic nerve stimulators. The team's findings have been published, and their innovative work has received recognition from the ANF. These advancements set the stage for future clinical applications, particularly in treating complex peripheral nerve injuries.

Dr. Franz emphasized the critical support provided by the ANF Development Grant. "The ANF Development Grant provided essential support and resources that facilitated collaboration between our team members and enabled us to conduct our research effectively. In particular, it protected research time for me as a physician-scientist, which was required to conduct these exciting studies," he says. 

Looking ahead, Dr. Franz's team plans to refine and optimize the therapeutic nerve stimulators for various applications, such as phrenic nerve repair and diaphragm muscle pacing. They also intend to conduct large animal safety studies with the aim of progressing to human clinical trials. Continued dissemination of their findings through publications and presentations will contribute to the broader field of peripheral nerve injury treatment.