Method for treating subjects suffering from chronic ulcers
A method, material, and kit for promoting neutrophils and monocytes to localize at a chronic ulcer site, promoting formation of a multi-layered cell structure in the ulcer site, promoting conversion of monocytes to macrophages, promoting secretion of the patient's own growth factors, promoting tissue proliferation and cell migration, promoting production and cross-linking of collagen at the chronic ulcer site, promoting growth of endothelial cells, promoting angiogenesis that was stalled at the chronic ulcer site, promoting formation of a vascular network and granulation, promoting oxygenation of the chronic ulcer site, and reducing one or more of purulent drainage, erythema, pain, warming, tenderness, induration, and bleeding at the chronic ulcer site.
1. A method of treating a chronic ulcer of skin and surrounding tissues in a subject in need thereof, comprising:
i) cleaning to remove bacteria and other pathogens and/or debriding the chronic ulcer of skin and surrounding tissues until the edges of the ulcer contain viable tissue;
ii) aseptically implanting into the chronic ulcer of skin and surrounding tissues of the subject a multilayer sheet of collagen material in dry state comprising (a) a barrier layer of collagen material having a smooth face and a rough fibrous face opposite said smooth face and (b) a spongeous matrix layer of collagen material connected to said rough fibrous face, said spongeous matrix layer of collagen material having an open sponge-like texture, such that the rough fibrous face of said barrier layer of collagen material to which is connected said spongeous matrix layer of collagen material having an open sponge-like texture, faces toward and is adjacent to the bed of the chronic ulcer of skin and surrounding tissues;
iii) hydrating the implanted multilayer sheet of collagen material in dry state using blood, an isotonic solution or a combination thereof; and
iv) providing a dressing over the implanted, hydrated multilayer sheet of collagen material, thereby restarting stalled cell migration, proliferation and angiogenesis at the chronic ulcer site.
2. The method of claim 1 , wherein the collagen of said barrier layer of collagen material is predominantly collagen I, collagen III or a mixture thereof.
3. The method of claim 1 , wherein the collagen of said spongeous matrix layer of collagen material is predominantly collagen I, collagen III or a mixture thereof.
4. The method of claim 1 , wherein the multilayer sheet of collagen material has a thickness of about 0.5-25 mm.
5. The method of claim 1 , wherein the chronic ulcer extends at least through the dermis and has been present for greater than 4 weeks.
6. The method of claim 1 , wherein the chronic ulcer extends at least through the hypodermis and has been present for greater than 6 weeks.
7. The method of claim 1 , further comprising applying a secondary dressing or re-dressing the chronic ulcer after step iv) is performed.
8. The method of claim 1 , further comprising applying sterile saline to remove a dressing material from the multilayer sheet of collagen material after step iv) is performed.
9. The method of claim 1 , further comprising changing the dressing over the implanted multilayer sheet of collagen material every 1 to 7 days after step iv) is performed.
10. The method of claim 1 , further comprising removing exudate from the chronic ulcer site every 1 to 7 days after step iv) is performed.
11. The method of claim 1 , further comprising inspecting the chronic ulcer every 1 to 7 days after step iv) and removing the dressing after a first visible epithelialization is observed at the chronic ulcer or removing the implanted multilayer sheet of collagen material and repeating steps i) to iv) if one or more of redness, swelling, hematomas, blistering, inflammation, excess exudate, infection, and necrosis are observed at the chronic ulcer.
12. The method of claim 1 , further comprising performing one or more of toe-blood pressure readings, pulse volume recordings, transcutaneous oxygen measurements, and skin perfusion pressure measurements.
13. The method of claim 1 , further comprising one or more of promoting neutrophils and monocytes to localize at the chronic ulcer site, promoting formation of a multi-layered cell structure in the ulcer site, promoting conversion of monocytes to macrophages, promoting secretion of the patient's own growth factors, promoting tissue proliferation and cell migration, promoting production and cross-linking of collagen at the chronic ulcer site, promoting growth of endothelial cells, promoting angiogenesis that was stalled at the chronic ulcer site, promoting formation of a vascular network and granulation, promoting oxygenation of the chronic ulcer site, and reducing one or more of purulent drainage, erythema, pain, warming, tenderness, induration, and bleeding at the chronic ulcer site.
14. The method of claim 1 , further comprising attracting one or more human cell types to the chronic ulcer of skin and surrounding tissues, wherein said one or more human cell types are human fibroblasts, human epidermal keratinocytes, human endothelial cells and human pluripotent stem cells.
15. The method of claim 1 , further comprising promoting attachment and growth of one or more human cell types in the chronic ulcer of skin and surrounding tissues, wherein said one or more human cell types are human fibroblasts, human epidermal keratinocytes, human endothelial cells and human pluripotent stem cells.
16. The method of claim 1 , further comprising inhibiting one or more MMPs in the chronic ulcer of skin and surrounding tissues, wherein the MMPs are a plurality of MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9.
17. The method of claim 1 , wherein the subject suffers from diabetic foot ulcer (DFU) or venous leg ulcer (VLU).
18. The method of claim 1 , wherein the multilayer sheet of collagen material in dry state has physical properties such that it absorbs about 7 to about 12 times its weight of biological fluids.
19. The method of claim 1 , wherein the multilayer sheet of collagen material has not been artificially cross-linked, has not had any growth factors or other ulcer-treating agents added to it, and/or has not had any antimicrobial agents added to it.
20. The method of claim 1 , further comprising, after 4 to 7 days, removing at least a portion of the implanted multilayer sheet of collagen material and repeating the method steps.
21. The method of claim 1 , further comprising providing a pH of or about 3.5 to about 6.5 in the chronic ulcer site.
22. A method of regenerating tissue at a chronic tissue ulcer site of a subject in need thereof, comprising:
i) aseptically implanting into the chronic tissue ulcer site a multilayer sheet of collagen material in dry state comprising (a) a barrier layer of collagen material having a smooth face and a rough fibrous face opposite said smooth face and (b) a spongeous matrix layer of collagen material connected to said rough fibrous face, said spongeous matrix layer of collagen material having an open sponge-like texture, such that said rough fibrous face of said barrier layer of collagen material to which is connected said spongeous matrix layer of collagen material having an open sponge-like texture faces toward and is adjacent to the chronic tissue ulcer; and
ii) hydrating the multilayer sheet of collagen material in dry state using blood, an isotonic solution or a combination thereof.
23. The method of claim 22 , wherein the collagen of said barrier layer of collagen material is predominantly collagen I, collagen III or a mixture thereof.
24. The method of claim 22 , wherein the collagen of said spongeous matrix layer of collagen material is predominantly collagen I, collagen III or a mixture thereof.
25. The method of claim 22 , wherein the multilayer sheet of collagen material has a thickness of about 0.5-25 mm.
26. The method of claim 22 , wherein the chronic ulcer extends at least through the dermis and has been present for greater than 4 weeks.
27. The method of claim 22 , wherein the chronic ulcer extends at least through the hypodermis and has been present for greater than 6 weeks.
28. A method of binding and preserving a subject's own growth factors in a chronic tissue ulcer site of a subject in need thereof, comprising:
i) aseptically implanting into the chronic tissue ulcer site of the subject a multilayer sheet of collagen material in dry state comprising (a) a barrier layer of collagen material having a smooth face and a rough fibrous face opposite said smooth face and (b) a spongeous matrix layer of collagen material connected to said rough fibrous face, said spongeous matrix layer of collagen material having an open sponge-like texture, such that said rough fibrous face of said barrier layer of collagen material to which is connected said spongeous matrix layer of collagen material having an open sponge-like texture faces toward and is adjacent to the chronic tissue ulcer site; and
ii) hydrating the implanted multilayer sheet of collagen material using blood, an isotonic solution or a combination thereof, thereby promoting binding of said subject's own growth factors with the multilayer sheet of collagen material and preservation of said subject's own growth factors and growth factor activity in the chronic tissue ulcer site thereby inducing expression of one or more growth factor-responsive genes in one or more human cell types in the chronic tissue ulcer site of the subject.
29. The method of claim 28 , wherein the growth factors are two or more of transforming growth factors (TGFs), fibroblast growth factors (FGFs), epidermal growth factor (EGF), Insulin-like Growth Factor (IGF-1), Platelet-derived Growth Factors (PDGFs), and vascular endothelial growth factors (VEGFs).
30. The method of claim 29 , wherein said one or more human cell types are human fibroblasts, human epidermal keratinocytes, human endothelial cells and human pluripotent stem cells.