Antiviral fiber assembly with cellulose sulfate

A process for producing a fiber assembly comprising hydrophobic fibers hydrophilized with an anionic surfactant that comprises a phosphate ester salt, and having a hyaluronidate inhibitory activity, the process comprising:

• treating a fiber assembly with an aqueous cellulose sulfate solution and drying;
• and
• then treating the fibers with a pH buffer and drying,
• wherein hydrophobic fibers are, or a fiber assembly containing hydrophobic fibers is, hydrophilized with the surfactant by an immersion method, a coating method, or a spray method, so as to form the hydrophilized fibers,
• the surfactant is attached to the fiber assembly in a range from 0.2 to 2.0 wt % relative to the total weight of the fiber assembly,
• the phosphate ester salt is a mixture of octyl phosphate salt or dodecyl phosphate salt with dipotassium tridecan-1-yl phosphate,
• the fiber assembly further retains cellulose sulfate and comprises pH buffer attached to the fiber assembly after the cellulose sulfate is retained thereon,
• the pH buffer is citrate buffer and is attached to the fiber assembly in an amount range from 0.1 to 0.2 wt % as an amount of attached components of the pH buffer relative to a total weight of the fiber assembly, and
• the fiber assembly has a hyaluronidase inhibitory activity of 70% or higher.