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US4655980A
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Process of making collagen membranes for medical use
Assignee: Angiotech Biomaterials Corp
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Filing: 1986-03-13
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Granted: 1987-04-07
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Expires: 2006-03-13
Abstract
Abstract A process for preparing collagen membranes useful in tissue repair, and wound healing and related membranous implant materials useful in both hard and soft tissue applications is disclosed. The resulting membranes and materials have properties which can be varied as desired to suit intended use. Variation results from altering the precise conditions of formation of the membrane or of related fibers and solids. The process comprises first forming a gel from solubilized collagen, followed by converting the gel into a one-, two- or three-dimensional membranous solid form. This conversion is performed either by applying pressure to the gel, or by disrupting the gel and separating the resulting precipitate for casting.
Inventors
- 👤 George Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:21
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/52; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61F2/08; A61F2/10; A61L26/00; A61L26/0009; A61L26/0028; A61L26/0033; A61L26/0061; A61L26/008; A61L27/14; A61L27/22; A61L27/24; C; C08; C08L; C08L89/00; C08L89/04; C08L89/06; A61F2310/00; A61F2310/00005; A61F2310/00365; Y; Y10; Y10S; Y10S128/00; Y10S128/08; Y10S602/00; Y10S602/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
50 words
A process for preparing a collagen membranous material, which process comprises: mechanically disrupting a collagen gel matrix, centrifuging the disrupted matrix at about 13,000×g for about one half-hour, homogenizing the resulting precipitate into a paste, casting the paste, and drying the cast paste at a temperature less than 37° C.
Claim 2
Dependent Claim
50 words
A process for preparing a collagen membranous material, which process comprises: mechanically disrupting a collagen gel matrix, centrifuging the disrupted matrix at about 13,000×g for about one half-hour, homogenizing the resulting precipitate into a paste, casting the paste, and drying the cast paste at a temperature less than 37° C.
Claim 3
Dependent Claim
16 words
The process of claim 1 which further includes the step of washing the paste and re-drying.
Claim 4
Dependent Claim
13 words
The process of claim 2 which further includes cross-linking the membrane with glutaraldehyde.
Claim 5
Dependent Claim
33 words
A process for preparing a collagen membrane which comprises forming a collagen gel matrix from a solution of collagen, followed by converting the gel to a membrane by the process of claim 1.
Claim 6
Dependent Claim
61 words
The process of claim 1 wherein the gel is formed by: cooling collagen in solution to approximately 4° C., treating the cooled solution with a buffer solution precooled to approximately 4° C., to obtain a mixture with a pH of approximately 7 and an ionic strength of approximately 0.05, and incubating the mixture at about 20° C. for about 16-20 hours.
Claim 7
Dependent Claim
48 words
The process of claim 1 wherein the gel is formed by: mixing, at ambient temperature, collagen in solution with sufficient salt/buffer solution to obtain a mixture with a pH of approximately 7 and approximately physiological ionic strength, and incubating the mixture at about 37° C. for 16-20 hours.
Claim 8
Dependent Claim
85 words
The process of claim 1 wherein the gel is formed by: precooling collagen in solution to about 4° C., mixing the cooled collagen in solution with a buffer solution, pre-cooled to about 4° C. to obtain a mixture with a pH of approximately 7 and ionic strength of about 0.05, and centrifuging the mixture at about 8000×q=13,000×q for 1-2 hours at about 20° C., immediately after mixing to obtain a supernatant, recovering the supernatant, and incubating the supenatant at about 20° C. for 16-20 hours.
Claim 9
Dependent Claim
17 words
The process of claim 1 wherein the gel is de-gassed and placed in a mold before disrupting.
Claim 10
Dependent Claim
11 words
A collagen membranous material prepared by the process of claim 1.
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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) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |