Nanotechnology could fix Achilles' heel

But the Achilles' heel in the prosthetic repertoire is fixing tendons… such as that found in the ankle. Now, researchers from the universities of Manchester and Liverpool have turned to nanotechnology to create artificial tendons using a spinning technique with a biodegradable plastic.

Writing in Inderscience's International Journal of Nanotechnology and Biomaterials Lucy Bosworth and Sandra Downes of the Department of Biomaterials, at the University of Manchester, and colleague Peter Clegg of The University of Liverpool, explain how materials science could be used to create very thin fibres to help regenerate damaged tendons.

Tendon injuries are a common problem facing anyone who takes part in sports or many other activities. A variety of tendons in man may be affected by injury, including tendons in the shoulder, elbows, biceps, knee, foot, and the notorious Achilles, the researchers say, while from the veterinary perspective, tendon problems in horses leads to costly losses to the racing industry.

Even with urgent treatment, scar tissue quickly forms as a tendon heals often leading to chronic pain and recurrent problems. Current treatments are ineffective, explain Bosworth and colleagues, so there is an urgent clinical need to find ways to prevent inferior scar tissue forming as an injury heals.

She and her colleagues reasoned that biocompatible fibres of the plastic polycaprolactone would not only be biocompatible and so be accepted by the body, but would be degraded over time as the injury heals and so replaced by new, healthy tissue.

They used a technique known as electrospinning to produce long, thin fibres of this material just a few thousandths the thickness of a human hair. These polymer nanofibres have a structure resembling the natural fibres of tendons; however, in this form they are not similar enough to be useful as a scaffold for tissue regeneration.

The Manchester team working with Peter Clegg, in Liverpool's Department of Veterinary Clinical Sciences, have now experimented with different electrospinning conditions to fabricate polycaprolactone nanofibres that form in long bundles that could be grouped together to form a temporary scaffold mimicking the structure of tendon tissue. Implanted into an injured tendon this scaffold material would act as a support for the growth of new tissue and prevent the formation of inferior scar tissue.