The present disclosure describes an implant for tissue replacement or augmentation including a resorbable non-pyrogenic porous body of irradiated oxidized cellulose, formed from a precursor reactive mixture of irradiated cellulose and an oxidizing agent, where the body forms a heterogeneous three-dimensional fibrillar network. Also disclosed is a method for producing a body of oxidized cellulose including irradiating a body of cellulose to form an irradiated body of cellulose, and reacting the irradiated body of cellulose with an oxidizing agent to form a non-pyrogenic porous and resorbable body of oxidized cellulose.