US5024841A
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US
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Collagen wound healing matrices and process for their production
Assignee: Surgical Specialties US Corp
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Filing: 1988-06-30
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Granted: 1991-06-18
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Expires: 2008-06-30
Abstract
Abstract Collagen implants that are useful as wound healing matrices are characterized by being formed of collagen fibrils that are not chemically cross-linked, and having a bulk density of 0.01 to 0.3 g/cm 3 and a pore population in which at least about 80% of the pores have an average pore size of 35 to 250 microns. The implants are capable of promoting connective tissue deposition, angiogenesis, reepithelialization, and fibroplasia. The wound healing matrix also serves as an effective sustained delivery system for bioactive agents.
Inventors
- 👤 George H. Chu
- 👤 Yasushi Ogawa
- 👤 John M. McPherson
- 👤 George Ksander
- 👤 Bruce Pratt
- 👤 Diana Hendricks
- 👤 Hugh McMullin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:31
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/54; A61K; A61K38/00; A61K38/16; A61K38/17; A61K38/39; A61L27/14; A61L27/22; A61L27/24; A61F; A61F2310/00; A61F2310/00005; A61F2310/00365; A61L2300/00; A61L2300/40; A61L2300/412; A61L2300/414; Y; Y10; Y10S; Y10S128/00; Y10S128/08
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
60 words
A collagen implant, comprising: a matrix having a density of about 0.01 to about 0.3 g/cm 3 , a thickness of about 1-20 mm, and having pores at least 80% of which are at least 35 μm in diameter, wherein said matrix comprises fibrillar atelopeptide collagen, wherein said fibrils are about 50-200 nm in diameter, and are not chemically cross-linked.
Claim 2
Dependent Claim
60 words
A collagen implant, comprising: a matrix having a density of about 0.01 to about 0.3 g/cm 3 , a thickness of about 1-20 mm, and having pores at least 80% of which are at least 35 μm in diameter, wherein said matrix comprises fibrillar atelopeptide collagen, wherein said fibrils are about 50-200 nm in diameter, and are not chemically cross-linked.
Claim 3
Dependent Claim
30 words
The implant of claim 1 wherein the implant is in aqueous slurry and further comprises heparin in a concentration of between about 5 and 500 μg per ml of slurry.
Claim 4
Dependent Claim
24 words
The implant of claim 1 which further comprises an amount of a biological growth factor effective for wound healing, oncostasis, osteogenesis, or hematopoietic modulation.
Claim 5
Dependent Claim
44 words
The implant of claim 3 wherein said growth factor is selected from TGF-betal, TGF-beta2, PDGF-AA, PDGF-AB, PDGF-BB, EGF, acidic FGF, basic FGF, TGF-alpha, connective tissue activating peptides, beta-thromboglobulin, insulin-like growth factors, tumor necrosis factors, interleukins, colony stimulating factors, erythropoietin, nerve growth factor, and interferons.
Claim 6
Dependent Claim
28 words
The implant of claim 4 which comprises a wound-healing effective amount of TGF-betal, TGF-beta2, PDGF-AA, PDGF-AB, PDGF-BB, EGF, acidic FGF, basic FGF, TGF-alpha, or connective tissue activating peptides.
Claim 7
Dependent Claim
103 words
A collagen implant, having the characteristics of a product produced by the following process: (a) providing an acidic aqueous solution of atelopeptide collagen which solution has a pH of less than 7; (b) precipitating the collagen from the solution by raising the pH of the solution until precipitation begins, forming a homogenous dispersion of the precipitated collagen fibrils; (c) casting the dispersion to about 1 to 20 mm thickness; (d) flash-freezing the cast dispersion at a temperature below about -20° C.; and (e) lyophilizing the frozen cast dispersion to form a collagen matrix with a water content of less than 25% by weight.
Claim 8
Dependent Claim
103 words
A collagen implant, having the characteristics of a product produced by the following process: (a) providing an acidic aqueous solution of atelopeptide collagen which solution has a pH of less than 7; (b) precipitating the collagen from the solution by raising the pH of the solution until precipitation begins, forming a homogenous dispersion of the precipitated collagen fibrils; (c) casting the dispersion to about 1 to 20 mm thickness; (d) flash-freezing the cast dispersion at a temperature below about -20° C.; and (e) lyophilizing the frozen cast dispersion to form a collagen matrix with a water content of less than 25% by weight.
Claim 9
Dependent Claim
19 words
The implant of claim 6 wherein said acidic aqueous solution comprises about 4 to about 20 mg/ml atelopeptide collagen.
Claim 10
Dependent Claim
26 words
The implant of claim 6 wherein said process is further characterized by: mixing 0.33 to 3.0 volumes of inert gas into said dispersion prior to casting.
Claim 11
Dependent Claim
41 words
The implant of claim 6 wherein said process is further characterized by: heating said collagen matrix at about 60° C. to about 120° C. for between about 4 hours and one week, at a relative humidity of less than about 55%.
Claim 12
Dependent Claim
14 words
The implant of claim 9 wherein said heating is performed at about 75°-90° C.
Claim 13
Dependent Claim
25 words
The implant of claim 6 wherein said process is further characterized by: compressing said collagen matrix to a density of about 0.05-0.3 g/cm 3 .
Claim 14
Dependent Claim
37 words
The implant of claim 6 wherein said process is further characterized by: adding an amount of heparin effective to provide the desired pore size in the final product matrix, during or after precipitation of said collagen fibrils.
Claim 15
Dependent Claim
11 words
The implant of claim 6 which further comprises a growth factor.
Claim 16
Dependent Claim
44 words
The implant of claim 13 wherein said growth factor is selected from TGF-betal, TGF-beta2, PDGF-AA, PDGF-AB, PDGF-BB, EGF, acidic FGF, basic FGF, TGF-alpha, connective tissue activating peptides, beta-thromboglobulin, insulin-like growth factors, tumor necrosis factors, interleukins, colony stimulating factors, erythropoietin, nerve growth factor, and interferons.
Claim 17
Dependent Claim
14 words
The process of claim 10 wherein said heating is performed at about 75°-90° C.
Claim 18
Dependent Claim
25 words
The process of claim 10 wherein said process is further characterized by: compressing said collagen matrix to a density of about 0.05-0.3 g/cm 3 .
Claim 19
Dependent Claim
21 words
The collagen implant as claimed in claim 1, further comprising: an amount of a biological growth factor effective for wound healing.
Claim 20
Dependent Claim
20 words
The collagen implant as claimed in claim 1, further comprising: a pharmaceutically effective amount of the biological growth factor TGF-β2.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-17 | 1994-12-17 | 1995-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-17 | 1998-12-17 | 1999-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-17 | 2002-12-17 | 2003-06-18 | $7700.00 | Window Closed / Lapsed |