Moving man-made objects is going to wear out them with time – it is an inevitable truth of life. We are used to repairing worn mechanisms and many different things, but what about the ones we put in human bodies?
An international team of scientists from York and Durham universities and Tsinghua University have created a way to repair low-friction surfaces in artificial joints rather easily.
Hip prostheses also wear out with time and use and eventually have to be replaced with new ones. Image credit: Deutsche Fotothek via Wikimedia (CC BY-SA 3.0 de)
Natural joints have an advantage of the ability to employ the body's healing power. Cartilage tissue can be damaged with time and it doesn’t heal too quickly, but at least there is a chance that it will repair itself. Man-made joints do not have these healing powers, which means that with time artificial joints start suffering increasing friction and may even need to be replaced again.
Scientists took inspiration from natural cartilage tissue and how it works to lubricate joints in humans. They’ve discovered that rings of sugar can help a polymer latch on to surfaces and repair damage and reduce friction. Researchers created a special low-friction coating for artificial joints. When it is rubbed off during normal use, the sugar ring allows the polymer to latch back into place essentially repairing the low-friction surface in the artificial joint.
Natural cartilage uses water to make a slick surface, which allows for slick, smooth movements and low risk of wear and tear. The new artificial coating also employs water in a similar way to make for a slippery surface. Polymer is dissolved in the water and latch back to the surface when it is damaged or worn. Although the new coating is not that similar in composition to natural tissues, its mode of action should be equally efficient. Scientists say that this technology may have a wider area of application in the future.
Dr Paul McGonigal, senior author of the study, said: “The components of our coatings are biocompatible, which makes them exciting prospects for use in medicine. We could also imagine developing a range of these materials that work in very different environments. Avoiding and repairing the damage caused by friction is equally important to ensure that cars and other machinery last for a long time”.
Of course, naturally, there is still a long way to go before this technology can be brought to a state where it could be used in a clinical setting. One of the major problems is that there needs to be a substantial amount of polymer dissolved in water. However, scientists hope that in the future they will solve this issue and the extra material will not be needed. This will help our ageing populations to have more comfortable, smoother artificial joints for longer.
Source: University of York