Researchers at the Indian Institute of Technology (IIT) Guwahati have taken a successful step towards the treatment of peripheral nerve damage. The solution has been the fibers of mulberry silk! The nerve conduits synthesized by the researchers were implanted in rats with sciatic nerve injury, which showed significant functional recovery one year after implantation.
Peripheral nerve damage is damage to the nerve that carry messages to and from the brain and spinal cord from and to the rest of the body. It may impair movement, sensation, organ or gland function, depending upon the nerve which is damaged. It can result from injuries caused by accidents, bullet wounds and surgical intervention.
Professor Utpal Bora and his team from Department of Biosciences and Bioengineering synthesized nerve conduits by electrospinning a mixture of silk fibroin protein and electrically conductive polymer called polyaniline. The silk extracted from the mulberry silkworm was combined with gold nano particles, resulting in the conduits having the strength and flexibility of silk and the electrically conductive property of gold.
“In tissue engineering, silk fibroin protein is routinely used as a scaffold. Since silk is not electrically conductive we coated it with polyaniline nanoparticles, which is a good electrical conductor,” tells Dr. Suradip Das from the Department of Biosciences and Bioengineering at IIT Guwahati, to The Hindu.
To fabricate a conduit which resembles the structure of the nerves, the team cultured Schwann cells, which produce myelin sheath around the nerves’ axons.
“The Schwann cells produce myelin sheath which act as biological insulators and play a crucial role in nerve regeneration. Our aim was to seed the conduit with Schwann cells so they initiate the regeneration process when the conduits are implanted in animals,” Dr Das said.
For testing the nerve conduit, the researchers removed 10 mm of sciatic nerve from rats and implanted the conduit. After six and twelve months, the conduits showed no deformation or dislocation in the treated animals. While in the untreated ones, the nerve gap had grown further. The team found regenerated neurons and Schwann cells inside the conduit. It had helped to initiate and enhance the quality of regeneration across the nerve gap.
“It would be affordable and easily available as one nine-yard silk saree can yield at least 1,000 of such conduits. Eventually, the body will replace the structure with its own collagen without any harm,” Bora says. What’s next then?
The research team wants to conduct trials on pigs which are genetically and physiologically closer to humans, to collect more data.
“There is a growing demand for nerve implants with increasing number of road accidents but there are no indigenously developed nerve conduits available in India. We have taken the first step to make locally developed nerve implants available in India,” says Professor Bora.
The results of the research have been published in the journal Biomedical Materials, which is available to read online. This is an achievement which will benefit infinite patients in the future and is a breakthrough in medical science.