Spinal injuries affect 2,50,000-5,00,000 people globally every year. According to scientists from the universities of Aberdeen and Oxford, cleaned, sterilized silk from Asian wild silkworms has the properties well suited for spinal cord repair following injury.
Currently, there is no cure for serious spinal cord trauma, in part because spinal nerves are unable to cross the scar tissue barrier and the cavity that forms in the cord after the injury.
Researchers from the University of Oxford and the University of Aberdeen in the UK discovered that modified silk from the Antheraea pernyi (AP) silk spinner had important properties desirable in a scaffold suitable for spinal repair.
Silk is made of chains and sheets of a protein called fibroin. The way the fibroin is arranged can vary depending on what type of silkworm produced it. Bombyx mori worms make most of the silk used in sutures.
But processed silk from another species, Antheraea pernyi, seemed to provide a much better surface for spinal nerves to grow, which the researchers already knew from previous studies.
The study found that AP silk has a repeated ‘RGD’ chemical sequence on its surface that binds to receptors on the nerve cells, encouraging them to attach to the material and grow along with it.
Additionally, the silk does not trigger a response by the immune system cells that would be present in the spinal cord, therefore minimising inflammation, researchers said.
The modified AP silk has the correct rigidity, does not trigger a response by the immune system cells that would be present in the spinal cord and degrades gradually over time.
The modified silk may also have the potential to aid repair following brain injury. The modified silk would be a scaffold that bridges the spinal injury cavity, supporting nerve growth across the damaged region.
The team believed that the discovery is a potentially important step towards the holy grail of medicine, the repair of the central nervous system. The study was published in the journal Scientific Reports.