The ubiquitous silk has now found a new use in medical science with scientists developing bone-grafting material used in surgery from the lustrous fibre.
Researchers at the Indian Institute of Technology, Guwahati along with colleagues in the US and Mexico made high-strength bone scaffolds--supporting material to bridge gaps between fractured bones--from a concoction of silk protein, fibres and polymer.
Scaffolds are required for a temporary period till the natural bone formation process is completed. Tested on rats, silk scaffold proved to provide a better grafting material to orthopedic surgeons than the existing choices, if it succeeds in human trials.
One of its advantages is that it does away with the current practice of a second surgery to remove implants after fractured bones are healed.
In many surgeries, implants made of either titanium or ceramic is used to tightly hold bone pieces together. Often a second surgery is done to take out the implant after bone growth is completed. Otherwise those implants can cause problems in the long run.
“This practice can be done away with silk scaffolds, which degrade naturally after healing,” one of the team members, Biman Mandal from IIT Guwahati told Deccan Herald.
With silk, scaffolds could be customised to have various ranges of degradation--from few months to two years--for catering to wide range of graft needs, he said.
Strength of the scaffold can be changed depending on the amount of silk protein and fibre in the final concoction. More fibre gives higher strength. The rate of degradation too could be varied with the nature of the fracture.
The scientists mixed a protein extracted from silkworm (Bombyx mori) with silk fibres and other chemicals to create the scaffold whose strength is close to the strength of body’s own soft bones found. They may become useful in plastic surgeries involving facial or head bones. “By adding microfibers to silk scaffolds, we get stronger mechanical properties and better bone formation. Both structure and function are improved,” said David Kaplan, Professor of Biomedical Engineering at the Tufts University, who led the project. The findings have been published on April 30 issue of the Proceedings of National Academy of Sciences.
The researchers claimed that by bonding silk microfibers to a silk protein scaffold, they have developed a fully biodegradable composite with high-compressive strength.