Cellulose fibres are impregnated with metal nano-particles at a concentration >； 1.5 w/w. The fibres are produced by swelling cellulose fibres in an aqueous alkali solution and then mixing the swollen fibres in an aqueous solution comprising a polymer and a metal salt. The preferred metal is silver and the preferred polymer is poly (N-vinyl pyrrolidone). The preferred alkali solution comprises a group 1 hydroxide, a tetraalkylammonium hydroxide, a mono-amine, a di-amine or N-methyl morpholine oxide (NMMO). The fibres are used in absorbent wound dressings, preferably together with other fibres, especially cellulose ethyl sulphate and lyocell.
