Patent US4621631A successfully refreshed from Google Patents.
US4621631A
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Process for the production of a bonded collagen fiber sheet
Assignee: TRUDELL MEDICAL A PARTNERSHIP OF ONTARIO
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Filing: 1983-12-23
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Granted: 1986-11-11
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Expires: 2003-12-23
Abstract
Abstract A process for the production of an unnative and biologically active bonded collagen fiber sheet from human placentae is described, in which process collagen-containing material from placentae is treated with a neutral salt solution, a solution of citric acid and with pepsin. The degraded collagen material obtained in this manner is, where appropriate, treated with a crosslinking agent. The collagen material produced in this manner is used for producing bonded collagen fiber sheets which can be used, for example, as covering for wounds.
Inventors
- 👤 Eric P. Paques
- 👤 Peter Fuhge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:55
CPC Classifications
C; C09; C09H; C09H7/00; A; A61; A61L; A61L15/00; A61L15/16; A61L15/20; A61L15/22; A61L15/32; A61L15/325; C09H3/00; Y; Y10; Y10S; Y10S128/00; Y10S128/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
104 words
A process for the production of a bonded collagen fiber sheet by sequentially treating collagen containing material, which have been comminuted and washed free of blood, with a 0.5-4 molar neutral salt solution, a 0.5-2 molar citric acid solution at pH 1-4, a pepsin solution, and, where appropriate, with an ion exchanger resin to remove low and high molecular weight contaminants, precipitating the collagen with sodium chloride, dissolving the preciptate in a weakly buffered solution at pH 4-6 to form a collagen solution, dialyzing the collagen solution against water so as to precipitate the collagen fibrils, suspending the collagen fibrils and drying the collagen.
Claim 2
Dependent Claim
104 words
A process for the production of a bonded collagen fiber sheet by sequentially treating collagen containing material, which have been comminuted and washed free of blood, with a 0.5-4 molar neutral salt solution, a 0.5-2 molar citric acid solution at pH 1-4, a pepsin solution, and, where appropriate, with an ion exchanger resin to remove low and high molecular weight contaminants, precipitating the collagen with sodium chloride, dissolving the preciptate in a weakly buffered solution at pH 4-6 to form a collagen solution, dialyzing the collagen solution against water so as to precipitate the collagen fibrils, suspending the collagen fibrils and drying the collagen.
Claim 3
Dependent Claim
38 words
The process as claimed in claim 1 further comprising treating the suspended collagen fibrils with a crosslinking agent at a concentration of 0.01-0.1 g/l at a temperature of 4°-37° C. for 0.5-24 hours and drying the crosslinked collagen.
Claim 4
Dependent Claim
11 words
The process of claim 2 wherein the crosslinking agent is formaldehyde.
Claim 5
Dependent Claim
17 words
The processes as claimed in claim 1, 3 or 2 wherein the collagen containing material is placentae.
Claim 6
Dependent Claim
16 words
A bonded collagen fiber sheet produced in accordance with the processes of claim 3 or 2.
Claim 7
Dependent Claim
23 words
The application of a bonded fiber sheet produced in accordance with the process of claims 3 or 2 as a covering for wounds.
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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) | 1989-11-10 | 1990-05-12 | 1990-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-10 | 1994-05-12 | 1994-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-10 | 1998-05-12 | 1998-11-11 | $7700.00 | Window Closed / Lapsed |