Hydrogels are polymers that are insoluble in water and that can form a sort of gel with enormous powers of absorption. They can contain up to 99% of water in their final form. The products obtained have a high degree of flexibility, comparable with that of living tissues, and ,as they are made up largely of water, they are naturally compatible with these tissues.
Many of them are based on silicone and are used to make monthly contact lenses that are permeable to oxygen and water, allowing the wearer to sleep with them and also to make those well known breast implants.
There are many other applications on the market, especially for burns and light wounds. The high water retention capacity of hydrogels means that they afford permanent moisturisation, facilitating healing. Similarly, several research groups are working on them because they could be used for bio-compatible implants that can release therapeutic substances over long periods of time.