Just Add Water!

New Hydrogel Allows Scientists to Replace Tendons and Cartilage

Stephanie Huang
Staff Writer

As you casually chug down a water bottle after your workout at the gym, the importance of water may not cross your mind. The fact that water composes above 60% of your body weight probably doesn’t cross your mind either. Have you ever thought of its potential ability to mend a torn ligament or tendon? Probably not.

Recently, a new and stronger hydrogel was engineered by researchers at MIT. Alginate, a substance found in algae, and polyacrylamide, the main ingredient in soft contact lenses, were added to a substance predominantly made up of water. Although each constituent of the mixture is weak and breaks easily, the combination can stretch up to twenty times its original length! This is because one polymer absorbs the shock of the stretch whereas the other one remains intact.

This hydrogel’s exceptional qualities do not stop there. Another experiment used to test the substance involved gluing a silicon wafer with hydrogel. When the silicon was smashed with a hammer, it broke, yet the pieces remained together by the hydrogel, thus giving the latter the nickname “superglue”. Two thin pieces of glass stuck together using this hydrogel were able to lift 55 pounds of weight, making the name all the more appropriate.

So, what exactly is a combination of algae extract and water useful for? Its elasticity and resistance are surely characteristics that make it ideal for 3D printing cartilage and ligaments, restoring mobility to many injured athletes.

Furthermore, its ability to diffuse medication into the body could also make it the “band-aid” of the future. This is particularly relevant for people suffering from severe burns. The compression bandages they wear to reduce scarring could easily be replaced by hydrogels. Currently, if health professionals want to put any electronics inside a patient’s body for monitoring purposes, the material would be hard and dry. However, adding a layer of hydrogel around the conductive material would make it more supple and moist. It would thus be better adapted to the human body.

All in all, this new substance is not only ground-breaking in terms of biotechnological advancement, but it is also fascinating in terms of its use of water. This striking resemblance with the body’s natural composition shows yet again Nature’s efficient design and how we can use our knowledge of the natural world to improve it.