Protease modulating wound interface layer for use with negative pressure wound therapy
Systems, methods, and apparatuses for modulating proteases including matrix metalloproteinase (MMP), elastase, and bacterial protease in a negative pressure therapy system are described. A mesh having a sacrificial substrate is included. The sacrificial substrate includes a plurality of collagen fibers reinforced with a supporting material and intersecting with each other to form a network of collagen fibers having a plurality openings. The openings of the plurality of openings have an average area between about 0.5 mm 2 and about 20 mm 2 to permit the flow of negative pressure through the mesh. The sacrificial substrate can also include oxidized regenerated cellulose.
1. A negative-pressure therapy system for modulating proteases in a tissue site, the system comprising:
a modulating layer including a plurality of collagen fibers reinforced with a supporting material and intersecting with each other to form a network of collagen fibers having a plurality openings;
wherein the openings of the plurality of openings have an average effective diameter between about 0.5 mm and about 5 mm to permit the flow of negative pressure through the network;
a manifold configured to be positioned adjacent the network;
a cover configured to be positioned over the manifold and the network and coupled to tissue adjacent the tissue site to form a sealed space; and
a negative-pressure source configured to be fluidly coupled to the manifold to provide negative pressure to the sealed space through the manifold and the network.
2. The method of claim 1 , wherein the openings have an average area between about 0.2 mm 2 and about 20.0 mm 2 .
3. The system of claim 1 , wherein the openings are generally circular in shape and have an average diameter between about 1 mm and about 2.5 mm.
4. The system of claim 1 , wherein the collagen fibers have a diameter of less than about 1 millimeter.
5. The system of claim 1 , wherein the collagen fibers have a diameter of between about 1 micron and 50 microns.
6. The system of claim 1 , wherein the network has a thickness between about 5 microns and about 2 millimeters.
7. The system of claim 1 , wherein the network has a thickness of about 25 microns.
8. The system of claim 1 , wherein the collagen fibers have a collagen content between about 10% and about 50% of the total material of the collagen fiber.
9. The system of claim 1 , wherein the collagen fibers comprise a string of collagen elements.
10. The system of claim 1 , wherein the supporting material comprises supporting fibers.
11. The system of claim 10 , wherein the supporting fibers are twisted with the plurality of collagen fibers.
12. The system of claim 10 , wherein the supporting fibers support separate collagen elements to form the plurality of collagen fibers.
13. The system of claim 12 , further comprising a plurality of supporting fibers operatively coupled to the plurality of collagen fibers.
14. The system of claim 12 , wherein the plurality of supporting fibers and the plurality of collagen fibers are woven together.
15. The system of claim 12 , wherein the supporting fibers are water soluble.
16. The system of claim 12 , wherein the supporting fibers are biodegradable.
17. The system of claim 12 , wherein the plurality of collagen fibers and the plurality of supporting fibers have a collagen content between about 10% and about 50% of the modulating layer.
18. The system of claim 12 , wherein the collagen fibers and supporting fibers are non-woven.
19. The system of claim 1 , wherein the collagen fibers comprise:
staple fibers formed from collagen; and
staple fibers formed from the supporting material;
wherein the staple fibers formed of collagen and the staple fibers formed of the supporting material are twisted together to form the collagen fibers.
20. The system of claim 19 , wherein the supporting material comprises one or more selected from a group consisting of: polyethylene oxide, alginate, polylactic acid, polyvinyl alcohol, polycapralactones, and polyamides.
21. The system of claim 19 , wherein a length of the staple fibers formed from collagen is between about 4 mm and about 6 mm.
22. The system of claim 19 , wherein the collagen fibers have a collagen content between about 10% and about 50% of the total material of the collagen fiber.
23. The system of claim 1 , further comprising a plurality of oxidized regenerated cellulose fibers intersecting the collagen fibers to form the network having the plurality of openings.
24. The system of claim 23 , wherein about 45% of the network comprises oxidized regenerated cellulose fibers.
25. The system of claim 23 , wherein about 55% of the network comprises collagen fibers.