US5116552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of dried collagen sponge
Assignee: Gunze Ltd
•
Filing: 1991-01-28
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Granted: 1992-05-26
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Expires: 2011-01-28
Abstract
Abstract A process for preparing a crack-free, dried collagen sponge having a shrinkage factor of up to 14%, including the steps of impregnating crosslinked collagen sponge with an aqueous solution of a hydrophilic organic solvent, freezing the sponge at a temperature of -80° C. or lower, and vacuum-drying the sponge.
Inventors
- 👤 Shinichiro Morita
- 👤 Nobuya Takahashi
- 👤 Takeshi Shimamoto
- 👤 Kazuya Matsuda
- 👤 Shigehiko Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:42
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; A; A61; A61F; A61F2/00; A61F2/02; A61F2/10; A61L; A61L27/00; A61L27/14; A61L27/22; A61L27/24; A61L27/50; A61L27/56; A61F2310/00; A61F2310/00005; A61F2310/00365; C08J2201/00; C08J2201/04; C08J2201/048; C08J2389/00; C08J2389/04; C08J2389/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
74 words
A process for preparing a crack-free, dried collagen sponge having a shrinkage factor of up to 14%, comprising the steps of impregnating a crosslinked collagen sponge with an aqueous solution of a hydrophilic organic solvent selected from the group consisting of aliphatic lower alcohols and aliphatic lower ketones, freezing the sponge and the aqueous solution therein at a temperature of -80° C. or lower, and vacuum-drying the sponge, the aqueous solution thereby being removed.
Claim 2
Dependent Claim
74 words
A process for preparing a crack-free, dried collagen sponge having a shrinkage factor of up to 14%, comprising the steps of impregnating a crosslinked collagen sponge with an aqueous solution of a hydrophilic organic solvent selected from the group consisting of aliphatic lower alcohols and aliphatic lower ketones, freezing the sponge and the aqueous solution therein at a temperature of -80° C. or lower, and vacuum-drying the sponge, the aqueous solution thereby being removed.
Claim 3
Dependent Claim
16 words
A process according to claim 1 wherein the hydrophilic organic solvent is a lower aliphatic alcohol.
Claim 4
Dependent Claim
13 words
A process according to claim 2 wherein the lower aliphatic alcohol is ethanol.
Claim 5
Dependent Claim
34 words
A process according to claim 1 wherein the crosslinked sponge is impregnated with the aqueous solution of hydrophilic organic solvent so that the solution accounts for at least 90% by volume of the sponge.
Claim 6
Dependent Claim
21 words
A process according to claim 1 wherein the freezing step is conducted at a temperature of -80° to about -135° C.
References Cited (Backward Citations)
US2610625A
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JPS5246282A
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JPS543779A
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US4412947A
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JPS6141452A
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JPS6116459A
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US4948540A
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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) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |