Antioxidant wound dressing materials
A wound dressing material comprising a solid bioabsorbable substrate dyed with an antioxidant dyestuff. The substrate may comprise collagen, chitosan or oxidized regenerated cellulose, and the dyestuff may for example be an aniline or acridine dye. The material preferably also comprises a silver salt, whereby the dyestuff stabilizes the silver salt. Also provided are methods of making such materials, and wound dressings comprising such materials.
1 . A wound dressing material comprising a solid bioabsorbable substrate dyed with an antioxidant dyestuff.
2 . A wound dressing material according to claim 1 , wherein the substrate comprises a solid bioabsorbable material selected from the group consisting of collagens, oxidized celluloses, chitosans, galactomannans, glycosaminoglycans, polylactide/polyglycolide, and mixtures thereof.
3 . A wound dressing material according to claim 2 , wherein the substrate comprises a solid bioabsorbable material selected from the group consisting of collagens, oxidized regenerated celluloses, chitosans, and mixtures thereof.
4 . A wound dressing material according to claim 3 , wherein the solid bioabsorbable substrate is selected from the group consisting of woven fabrics, knitted fabrics, nonwoven fabrics, freeze-dried sponges, solvent-dried sponges and combinations thereof.
5 . A wound dressing material according to claim 4 , wherein the antioxidant dyestuff is selected from the group consisting of aniline dyes, acridine dyes, thionine dyes, bis-naphthalene dyes, thiazine dyes, azo dyes, anthraquinones, and mixtures thereof.
6 . A wound dressing material according to claim 4 , wherein the antioxidant dyestuff is selected from the group consisting of gentian violet, aniline blue, methylene blue, crystal violet, acriflavine, 9-aminoacridine, acridine yellow, acridine orange, proflavin, quinacrine, brilliant green, trypan blue, trypan red, malachite green, azacrine, methyl violet, methyl orange, methyl yellow, ethyl violet, acid orange, acid yellow, acid blue, acid red, thioflavin, alphazurine, indigo blue, methylene green, and mixtures thereof.
7 . A wound dressing material according to claim 6 , wherein the antioxidant dyestuff is present in an amount of from about 0.2 to about 2 wt. % based on the dry weight of the material.
8 . A wound dressing material according to claim 7 , wherein the material further comprises a silver salt, whereby the dyestuff photostabilizes the silver salt.
9 . A wound dressing material according to claim 8 , wherein the polymeric substrate comprises an anionic polymer, and said silver salt comprises a salt of Ag + with the anionic polymer.
10 . A wound dressing material according to claim 9 , wherein the composition comprises from about 0.01 wt. % to about 5 wt. % of silver, based on the dry weight of the composition.
11 . A wound dressing material according to claim 7 , wherein the material is in sheet form.
12 . A wound dressing material according to claim 7 , wherein the material is sterile and packaged in a microorganism-impermeable container.
13 . A wound dressing material according to claim 7 , wherein the material has a free radical activity in the diphenylpicrylhydrazyl (DPPH) test for antioxidant activity as herein defined of at least about 15%.
14 - 19 . (canceled)