US4412947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collagen sponge
Assignee: Seton Co
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Filing: 1982-05-26
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Granted: 1983-11-01
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Expires: 2002-05-26
Abstract
Abstract A process for preparing a coherent porous collagen sheet material is comprised of forming natural insoluble particulate collagen in substantially pure form and suspending the particulate collagen in a weak aqueous organic acid solution while maintaining the collagen in particulate form. The suspension is freeze-dried to form a coherent porous native collagen sheet material which is useful as a wound dressing, burn dressing, hemostatic sheet or the like.
Inventors
- 👤 Gheorghe Cioca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:30
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/32; A61L15/325; A61K; A61K9/00; A61K9/70; A61L26/00; A61L26/0009; A61L26/0028; A61L26/0033; C; C08; C08J; C08J9/00; C08J9/28; C08L; C08L89/00; C08L89/04; C08L89/06; C08J2389/00; C08J2389/04; C08J2389/06; F; F16; F16C; F16C2208/00; F16C2208/20; F16C2208/30; F16C2208/32; Y; Y10; Y10S; Y10S128/00; Y10S128/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
51 words
A process of preparing a coherent, porous collagen sheet material comprising: forming natural insoluble particulate collagen in substantially pure form; suspending said particulate collagen in a weak aqueous organic acid solution while maintaining said collagen in particulate form; and freeze-drying said suspension to form a coherent, porous native collagen sheet material.
Claim 2
Dependent Claim
51 words
A process of preparing a coherent, porous collagen sheet material comprising: forming natural insoluble particulate collagen in substantially pure form; suspending said particulate collagen in a weak aqueous organic acid solution while maintaining said collagen in particulate form; and freeze-drying said suspension to form a coherent, porous native collagen sheet material.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein said natural insoluble particulate collagen has a particle size of less than about 1 millimeter.
Claim 4
Dependent Claim
21 words
The process of claim 2 wherein said natural insoluble particulate collagen has a particle size of less than about 0.5 millimeter.
Claim 5
Dependent Claim
28 words
The process of claim 1 wherein said weak organic acid is selected from the group consisting of acetic acid, citric acid, lactic acid, ascorbic acid and tartaric acid.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein said particulate collagen suspension is at a level of up to about 5 percent by weight collagen.
Claim 7
Dependent Claim
23 words
The process of claim 5 wherein said particulate collagen suspension is at a level of up to about 3 percent by weight collagen.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein said aqueous acid solution is at a level of up to 1 percent by weight acid.
Claim 9
Dependent Claim
42 words
The process of claim 1 wherein said freeze-drying is conducted by freezing said solution to effect a temperature reduction rate of -18° to -24° C./hr., and vacuum drying said solution at 10 -3 to 10 -5 torr for at least 12 hours.
Claim 10
Dependent Claim
16 words
A coherent, porous native collagen sheet material produced in accordance with 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) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |