Spider Silk Could Revolutionize Nerve Repair Surgery, Scientists Report

International research teams have developed bioengineered surgical devices using spider and silkworm silk that show remarkable effectiveness in repairing severed peripheral nerves, with human clinical trials now underway.

An international team of scientists has achieved a significant breakthrough in nerve regeneration, demonstrating that surgical devices made from spider and silkworm silk can effectively repair severed nerves with results comparable to current gold-standard treatments. Published in April 2023 in the journal Advanced Healthcare Materials, the research represents a major step toward creating sustainable, off-the-shelf alternatives for the approximately one million people worldwide who suffer peripheral nerve injuries each year.

The collaborative study, conducted by researchers at the University of Oxford and the Medical University of Vienna (MedUni Vienna), introduced what the team calls "silk-in-silk" nerve guidance conduits—hollow tubes constructed from silkworm silk (Bombyx mori) and filled with dragline silk fibers harvested from golden orb-web spiders (Trichonephila edulis). These devices are designed to be sutured to both ends of an injured nerve, creating a biological bridge that guides the growth of nerve fibers and regenerative cells across damaged gaps.

The results from preclinical trials on rat models demonstrated impressive regenerative capabilities. When tested on 2-centimeter gaps in rat sciatic nerves—the largest gap distance successfully bridged in such studies using nerve guidance conduits—the silk devices achieved regeneration performance comparable to nerve autografts, which currently represent the clinical gold standard. Even more remarkably, Schwann cells—the key drivers of peripheral nerve regeneration—adhered strongly to both the tube walls and the dragline silk fibers, migrating at speeds exceeding 1.1 millimeters per day.

"Our advanced silk-in-silk nerve guides combine the excellent ability of silkworm silk to be processed into three-dimensional structures with the outstanding cell adhesion qualities of spider dragline silk," explained Dr. Joachim Lacour of MedUni Vienna, who led the study. The research demonstrated that both types of silk played crucial roles in the healing process. When researchers tested empty silk tubes without the spider silk filling, nerve fibers grew more slowly and showed less organized regeneration patterns, highlighting the importance of the internal spider silk framework.

Professor Fritz Vollrath of Oxford's Department of Biology, a co-founder of Oxford Biomaterials and co-author on the study, has spent decades studying spider silk's remarkable properties. "Animal silks offer exceptional mechanical and biological properties and versatile manufacturing possibilities to assist the re-engineering of tissue," Vollrath noted. His earlier work had established that "you can make very long fibres and potentially nerve cells will grow along these filaments."

The clinical significance of this research cannot be overstated. Peripheral nerve injuries, which often result from traumatic accidents, falls, and surgical complications, affect between 13 and 23 people per 100,000 annually. These injuries frequently lead to permanent disability, chronic pain, and significant reductions in quality of life. Current treatment options are limited and problematic—surgeons typically rely on autografts (taking nerve tissue from elsewhere in the patient's body) or synthetic conduits that work only for very small gaps and often fail to achieve functional recovery.

The technology has already advanced toward clinical application through Newrotex Ltd, a spin-out company from Oxford Biomaterials that is developing silk-based nerve repair devices. In late 2023, Newrotex received regulatory approval in Panama for first-in-human clinical trials of SilkAxons™, their advanced bioengineered nerve guidance technology. These trials represent a critical milestone in translating decades of silk research into practical medical treatments.

Beyond the clinical benefits, spider silk-based devices offer significant advantages over current alternatives. Unlike synthetic implants that may trigger immune responses or require removal surgeries, silk is fully biodegradable and biocompatible, breaking down naturally as the nerve regenerates. The material is also sustainable and potentially cost-effective compared to the expensive cadaver donor nerves sometimes used in reconstruction procedures.

Why it matters

This breakthrough addresses a critical unmet need in reconstructive medicine, offering hope to millions of patients suffering from peripheral nerve injuries that currently have limited treatment options. By harnessing nature's own engineering—spider silk, which has evolved over 400 million years to be stronger than steel by weight—scientists are creating medical devices that work with the body's natural healing processes rather than against them.

Background

The use of silk in medicine dates back thousands of years, with ancient Chinese physicians using silkworm silk for sutures as early as 500 CE. However, modern biomedical silk research accelerated significantly in the early 2000s when scientists began understanding how to process silk proteins while preserving their remarkable mechanical properties. Spider silk presents particular challenges for medical applications because spiders cannot be farmed like silkworms—they are territorial and cannibalistic. Recent advances in recombinant DNA technology now allow scientists to produce spider silk proteins through genetically modified organisms, opening the door to scalable production of this extraordinary material.

What's next

Newrotex's clinical trials in Panama mark the beginning of what researchers hope will be a transformation in nerve repair surgery. If successful, these trials could pave the way for regulatory approvals in larger markets and the development of silk-based devices for even more challenging applications, including spinal cord injury repair. Professor Vollrath has previously noted that "the ultimate aim is to repair spinal cord in this way"—a goal that, if achieved, could offer hope to millions of patients with paralysis and other severe neurological conditions.