Biomedical Applications of Hydrogels HandbookHydrogels are networks of polymer chains which can produce a colloidal gel containing over 99 per cent water. The superabsorbency and permeability of naturally occurring and synthetic hydrogels give this class of materials an amazing array of uses. These uses range from wound dressings and skin grafts to oxygen permeable contact lenses to biodegradable delivery systems for drugs or pesticides and scaffolds for tissue engineering and regenerative