US4997425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wound dressing
Assignee: Zeon Corp
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Filing: 1990-03-29
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Granted: 1991-03-05
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Expires: 2010-03-29
Abstract
Abstract A wound dressing having a porous layer with a good affinity to tissue of organisms comprising (a) a first layer to be placed on the wound surface having pores of 20 to 500 μm in diameter, and 1 to 10 mm thick, and (b) a second layer remote from the wound surface having pores not more than 20 μm in diameter, and 0.5 to 5 μm thick. The first layer can be provided with an antimicrobial of not more than 50% by weight, and the second layer can contain an antimicrobial of 10 to 80% by weight.
Inventors
- 👤 Nobuyuki Shioya
- 👤 Yoshimitsu Kuroyanagi
- 👤 Yasumi Koganei
- 👤 Ryuichiro Yoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:16
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/46; A61F; A61F13/00; A61F13/00051; A61F13/00063; A61L15/425; A61F13/15; A61F13/84; A61F13/8405; A61F2013/00089; A61F2013/00157; A61F2013/00217; A61F2013/00221; A61F2013/00246; A61F2013/00255; A61F2013/00361; A61F2013/00365; A61F2013/00463; A61F2013/00519; A61F2013/00855; A61F2013/00863; A61F2013/00902; A61F2013/0091; A61F13/53; A61F2013/530802; A61F2013/53081; A61L2300/00; A61L2300/40; A61L2300/404
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
118 words
A wound dressing of a porous layer structure having good affinity to tissues of organisms comprising: (a) a first portion having a reinforcing material embedded therein, said first portion adapted to be placed on the wound surface and having a thickness of 1 to 10 mm; (b) a second portion superimposed on the first portion, said second portion having a thickness of 0.5 to 5 μm; (c) said first and second portions are continuously formed, with no boundary therebetween by quenching and freeze drying a solution of a polyamino acid under vacuum in a mold including the reinforcing material; and (d) the first portion has pores having diameters which decrease from the wound surface toward the second portion.
Claim 2
Dependent Claim
118 words
A wound dressing of a porous layer structure having good affinity to tissues of organisms comprising: (a) a first portion having a reinforcing material embedded therein, said first portion adapted to be placed on the wound surface and having a thickness of 1 to 10 mm; (b) a second portion superimposed on the first portion, said second portion having a thickness of 0.5 to 5 μm; (c) said first and second portions are continuously formed, with no boundary therebetween by quenching and freeze drying a solution of a polyamino acid under vacuum in a mold including the reinforcing material; and (d) the first portion has pores having diameters which decrease from the wound surface toward the second portion.
Claim 3
Dependent Claim
18 words
A wound dressing claimed in claim 1 wherein said first layer of said dressing is a sponge layer.
Claim 4
Dependent Claim
13 words
A wound dressing claimed in claim 1 wherein said reinforcing material is flexible.
Claim 5
Dependent Claim
21 words
A wound dressing according to claim 1 wherein said first layer portion has pores of 20 to 500 μm in diameter.
Claim 6
Dependent Claim
24 words
A wound dressing according to claim 1 wherein the second layer has pores and said pores are not more than 20 μm in diameter.
Claim 7
Dependent Claim
23 words
The wound dressing of claim 1 further comprising a coating on a surface of the wound dressing having a high affinity to tissues.
Claim 8
Dependent Claim
147 words
A wound dressing of a porous layer structure having good affinity to tissues of organisms comprising: (a) a first portion having a reinforcing material embedded therein, said first portion adapted to be placed on the wound surface, having a thickness of 1 to 10 mm and containing an antimicrobial agent in an amount of not more than 50% by weight; and (b) a second portion superimposed on the first portion, said second portion having a thickness of 0.5 to 5 μm, and containing an antimicrobial agent in an amount of 10 to 80% by weight; (c) said first and second portions are continuously formed, with no boundary therebetween by quenching and freeze drying a solution of a polyamino acid under vacuum in a mold including the reinforcing material; and (d) the first portion has pores having diameters which decrease from the wound surface toward the second portion.
Claim 9
Dependent Claim
147 words
A wound dressing of a porous layer structure having good affinity to tissues of organisms comprising: (a) a first portion having a reinforcing material embedded therein, said first portion adapted to be placed on the wound surface, having a thickness of 1 to 10 mm and containing an antimicrobial agent in an amount of not more than 50% by weight; and (b) a second portion superimposed on the first portion, said second portion having a thickness of 0.5 to 5 μm, and containing an antimicrobial agent in an amount of 10 to 80% by weight; (c) said first and second portions are continuously formed, with no boundary therebetween by quenching and freeze drying a solution of a polyamino acid under vacuum in a mold including the reinforcing material; and (d) the first portion has pores having diameters which decrease from the wound surface toward the second portion.
Claim 10
Dependent Claim
18 words
A wound dressing claimed in claim 7 wherein said first layer of said dressing is a sponge layer.
Claim 11
Dependent Claim
13 words
A wound dressing claimed in claim 7 wherein said reinforcing material is flexible.
Claim 12
Dependent Claim
21 words
A wound dressing according to claim 7 wherein said first layer portion has pores of 20 to 500 μm in diameter.
Claim 13
Dependent Claim
28 words
A wound dressing according to claim 7 wherein the second layer has pores and the pores of the second portion are not more than 20 μm in diameter.
Claim 14
Dependent Claim
23 words
The wound dressing of claim 7 further comprising a coating on a surface of the wound dressing having a high affinity to tissues.
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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) | 1994-03-04 | 1994-09-03 | 1995-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-04 | 1998-09-03 | 1999-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-04 | 2002-09-03 | 2003-03-05 | $7700.00 | Window Closed / Lapsed |