Chitosan superfine fiber systems

A bioactive composition comprising:

• at least ten to fifty layers of non-woven chitosan-based fibers having a mean interconnected pore size between 1.5 to about 40 microns, wherein the non-woven chitosan-based fibers in at least one of the layers consist of a combination of:
• (a) centrifugally spun chitosan-based fibers with a diameter less than or equal to about 10 microns and greater than 2 microns;
• and
• (b) centrifugally spun chitosan-based fibers having a diameter less than or equal to 2 microns,
• wherein the non-woven chitosan-based fibers comprise chitosan consisting of linear polymers of poly-β-(1-4)N-acetyl D-glucosamine comprising at least ten (10) linked monomer units of D-glucosamine and N-acetyl D-glucosamine monomers with β-(1-4) glycosidic linkages, wherein the non-woven chitosan-based fibers in the at least one layer have a mean fiber diameter greater than 0.5 microns, and wherein the non-woven chitosan-based fibers in the at least one layer have a chitosan content of at least about 20% (w/w) and an optional chitosan salt.