Hydrogel with a water content of at least 50 wt.% comprises a gel-forming polysaccharide, an acrylic acid derivative and an electrolyte mixture. Independent claims are also included for: (1) wound filler comprising a hydrogel as above； (2) wound dressing comprising a hydrogel as above； (3) producing a hydrogel by preparing an aqueous solution containing an acrylic acid derivative, adding a suspension of a powdered polysaccharide and irradiating the mixture with electromagnetic radiation or electron or positron radiation to adjust the viscosity of the hydrogel.
