When a surgeon needs to repair a broken bone requiring screws and plates to help bond the broken sections so the fracture to heal, the "fixation devices" are usually made of metal alloys. But metal devices may have potential disadvantages. Resorbable fixation devices, made of synthetic polymers, also have some disadvantages. A third option, is silk, says a team of investigators from Tufts University School of Engineering, Medford, MA, and Beth Israel Deaconess Medical Center (BIDMC), Boston.

Surgical screws made from silkworm cocoons could be used to repair bone fractures. (Credit: Gabriel Perrone)

They have developed surgical plates and screws that may not only offer improved bone remodeling following injury, but importantly, can also be absorbed by the body over time, eliminating the need for surgical removal of the devices.

Silk materials are extremely robust, maintain structural stability under very high temperatures and withstand other extreme conditions, and they can be sterilized, they explain.

Since silk can stabilize and deliver bioactive components, silk-based plates and screws could deliver antibiotics to prevent infection, pharmaceuticals to enhance bone regrowth, and other therapeutics to support healing, they said.

The Tufts researchers used protein from silkworm cocoons to form surgical plates and screws. Produced from the glands of the silkworm, the silk protein is folded in complex ways that give it unique properties of both exceptional strength and versatility.