US4570629A
Expired / Lapsed
US
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Hydrophilic biopolymeric copolyelectrolytes, and biodegradable wound dressing comprising same
Assignee: University of Illinois Foundation
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Filing: 1983-09-21
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Granted: 1986-02-18
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Expires: 2003-09-21
Abstract
Abstract Hydrophilic biopolymeric copolyelectrolytes comprising (a) a water-soluble linear anionic protein polyelectrolyte component derived from keratin and (b) a water-soluble linear cationic biopolymer polyelectrolyte component derived from at least one biopolymer selected from the group consisting of collagen and a glucosaminoglycan. Hydrogel membranes formed from the copolyelectrolytes are useful as biodegradable dressings for denuded tissue wound sites.
Inventors
- 👤 Abe Widra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:56
CPC Classifications
A; A61; A61L; A61L33/00; A61L33/0005; A61L33/0011; A61L33/0029; A61L26/00; A61L26/0009; A61L26/0023; A61L26/0028; A61L26/0033; A61L27/00; A61L27/28; A61L27/34; C; C08; C08H; C08H1/00; C08H1/06; C08L; C08L5/00; C08L5/08; A61F; A61F2310/00; A61F2310/00005; A61F2310/00365
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
41 words
A hydrophilic biopolymeric copolyelectrolyte comprising (a) a water-soluble linear anionic protein polyelectrolyte component derived from keratin, and (b) a water-soluble linear cationic biopolymer polyelectrolyte component derived from at least one biopolymer selected from the group consisting of a glucosaminoglycan and collagen.
Claim 2
Dependent Claim
41 words
A hydrophilic biopolymeric copolyelectrolyte comprising (a) a water-soluble linear anionic protein polyelectrolyte component derived from keratin, and (b) a water-soluble linear cationic biopolymer polyelectrolyte component derived from at least one biopolymer selected from the group consisting of a glucosaminoglycan and collagen.
Claim 3
Dependent Claim
21 words
The copolyelectrolyte of claim 1 comprising an integral mixture of said anionic protein polyelectrolyte component and said cationic protein polyelectrolyte component.
Claim 4
Dependent Claim
45 words
The copolyelectrolyte of claim 1 comprising one or more layers of said anionic protein polyelectrolyte component, which anionic layers may be the same or different, alternated with one or more layers of cationic protein polyelectrolyte component, which cationic layers may be the same or different.
Claim 5
Dependent Claim
14 words
The copolyelectrolyte of claim 1, wherein said anionic protein polyelectrolyte component is ammonium keratinate.
Claim 6
Dependent Claim
15 words
The copolyelectrolyte of claim 4, wherein the keratin moiety of said ammonium keratinate is alpha-keratose.
Claim 7
Dependent Claim
10 words
The copolyelectrolyte of claim 1, wherein said glucosaminoglycan is chitosan.
Claim 8
Dependent Claim
15 words
The copolyelectrolyte of claim 1, wherein said cationic biopolymer polyelectrolyte component is a biopolymer carboxylate.
Claim 9
Dependent Claim
13 words
The copolyelectrolyte of claim 7, wherein said biopolymer carboxylate is a biopolymer acetate.
Claim 10
Dependent Claim
32 words
The copolyelectrolyte of claim 1, wherein the weight ratio of said anionic protein polyelectrolyte component to said cationic biopolymer polyelectrolyte component is within the range of from about 0.001:1 to about 16:1.
Claim 11
Dependent Claim
32 words
The copolyelectrolyte of claim 9, wherein the weight ratio of said anionic protein polyelectrolyte component to said cationic biopolymer polyelectrolyte component is within the range of from about 0.001:1 to about 7:1.
Claim 12
Dependent Claim
36 words
The copolyelectrolyte of claim 10, wherein the biopolymer moiety of said cationic biopolymer polyelectrolyte component is a mixture of chitosan and collagen in a chitosan to collagen weight ratio of from about 0.5:1 to about 13:1.
Claim 13
Dependent Claim
19 words
A composition comprising the copolyelectrolyte of claim 1, and a flexibility-and/or adhesion-enhancing amount of a non-toxic plasticizer or softener.
Claim 14
Dependent Claim
12 words
The composition of claim 12, wherein said plasticizer or softener is glycerol.
Claim 15
Dependent Claim
11 words
A composition comprising the copolyelectrolyte of claim 1, and an antibiotic.
Claim 16
Dependent Claim
11 words
A composition comprising the copolyelectrolyte of claim 1 in powder form.
Claim 17
Dependent Claim
11 words
A hydrogel comprising the copolyelectrolyte of claim 1 in hydrated form.
Claim 18
Dependent Claim
24 words
A membrane comprising at least one layer of the hydrogel of claim 16, said membrane having a thickness of at least about 1 mil.
Claim 19
Dependent Claim
26 words
The membrane of claim 17, wherein both cationic chitosan and cationic collagen are present either in the same hydrogel layer or in two separate hydrogel layers.
Claim 20
Dependent Claim
18 words
A biodegradable dressing for burn wounds and other denuded tissure wound sites, comprising the membrane of claim 17.
Claim 21
Dependent Claim
19 words
The dressing of claim 19, wherein said membrane includes a flexibility-and/or adhesion-enhancing amount of a non-toxic plasticizer or softener.
Claim 22
Dependent Claim
12 words
The dressing of claim 20, wherein said plasticizer or softener is glycerol.
Claim 23
Dependent Claim
11 words
The dressing of claim 19, wherein said membrane includes an antibiotic.
Claim 24
Dependent Claim
26 words
A method for applying the dressing of claim 19 onto the wound site, wherein formation of said hydrogel is effected in situ on the wound site.
Claim 25
Dependent Claim
19 words
The method of claim 23, wherein said copolyelectrolyte is preformed and applied to said wound site in dehydrated form.
Claim 26
Dependent Claim
24 words
The method of claim 23, wherein said anionic protein polyelectrolyte component and said cationic biopolymer polyelectrolyte component are individually applied to said wound site.
Claim 27
Dependent Claim
23 words
The method of claim 25, wherein at least one of said two components is applied to said wound site as an aqueous solution.
Claim 28
Dependent Claim
20 words
The method of claim 26, wherein one of said two components is applied to said wound site in solid form.
Claim 29
Dependent Claim
20 words
The method of claim 27, wherein said solid form includes a flexibility-and/or adhesion-enhancing amount of a non-toxic plasticizer or softener.
Claim 30
Dependent Claim
22 words
The method of claim 28, wherein said component applied in solid form comprises chitosan acetate, and said plasticizer or softener is glycerol.
Claim 31
Dependent Claim
28 words
A method for applying the dressing of claim 19 onto the wound site wherein said hydrogel is preformed and applied to the wound site as a self-annealing paste.
Claim 32
Dependent Claim
12 words
A biodegradable lining for surgical prostheses, comprising the copolyelectrolyte of claim 1.
Claim 33
Dependent Claim
17 words
The method of claim 24, wherein said copolyelectrolyte is applied to said wound site in powder form.
Claim 34
Independent Claim
66 words
A method of preparing a biodegradable dressing for burn wounds and other denuded tissue wound sites, comprising forming a membrane of at least one layer of a hydrophilic biopolymeric copolyelectrolyte including (a) a water-soluble linear anionic protein polyelectrolyte component derived from keratin, and (b) a water-soluble linear cationic biopolymer polyelectrolyte component derived from at least one biopolymer selected from the group consisting of glucosaminoglycan and collagen.
Claim 35
Independent Claim
66 words
A method of preparing a biodegradable dressing for burn wounds and other denuded tissue wound sites, comprising forming a membrane of at least one layer of a hydrophilic biopolymeric copolyelectrolyte including (a) a water-soluble linear anionic protein polyelectrolyte component derived from keratin, and (b) a water-soluble linear cationic biopolymer polyelectrolyte component derived from at least one biopolymer selected from the group consisting of glucosaminoglycan and collagen.
Claim 36
Dependent Claim
39 words
The method of claim 33 wherein a solution of said anionic protein polyelectrolyte component and a solution of said cationic biopolymer polyelectrolyte component are mixed together and the resulting mixture is allowed to dry down to form said membrane.
Claim 37
Dependent Claim
28 words
The method of claim 33 comprising preparing a membrane of a cationic biopolymer polyelectrolyte component and spraying said membrane with a solution of an anionic protein polyelectrolyte component.
Claim 38
Dependent Claim
14 words
The method of claim 33 further comprising the step of dehydrating said copolyelectrolyte membrane.
Claim 39
Dependent Claim
21 words
The method of claim 36, further comprising the step of reducing said dehydrated copolyelectrolyte membrane to a powder or granular form.
Claim 40
Dependent Claim
18 words
The method of claim 37, wherein said powder or granular dehydrated copolyelectrolyte membrane is rehydrated prior to use.
Claim 41
Dependent Claim
25 words
The method of claim 37, wherein said powder or granular dehydrated copolyelectrolyte membrane is applied to the wound site and allowed to rehydrate in situ.
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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) | 1989-02-17 | 1989-08-19 | 1990-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-17 | 1993-08-19 | 1994-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-17 | 1997-08-19 | 1998-02-18 | $7700.00 | Window Closed / Lapsed |