Researchers at the University of Connecticut (UConn) in the US have used silk fibres to develop a biodegradable composite for the repair of load-bearing bones.
Led by UConn professor Mei Wei, the team used the silk fibroin protein present in fibres spun by spiders and moths for their new composite. The protein is tough and features tensile strength.
It is generally used in medical sutures and tissue engineering for its strength and biodegradable nature.
The new material is intended to provide an alternative for commonly used metal plates that leach ions into the surrounding tissue, leading to inflammation and irritation.
In addition, the metal products are stiff and may result in the growth of weaker and more vulnerable bones in the case of too much load.
The researchers aimed for a strong and stiff yet flexible composite to allow natural motion and mobility range for patients while the bone healed.
They chose to use a combination of long silk and polylactic acid fibres coated with hydroxyapatite-based bioceramic particles. These coated fibres were packed in layers on a steel frame and compressed into a dense composite bar using a hot compression mould.
Wei said: “Our results are really high in terms of strength and flexibility, but we feel that if we can get every component to do what we want them to do, we can get even higher.”
The researchers further said that the composite is resilient and degrades after one year, eliminating the need for surgery to remove it.