US4161948A
Expired / Lapsed
US
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Synthetic membrane for wound-dressings
Assignee: Battelle Memorial Institute Inc
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Filing: 1978-01-16
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Granted: 1979-07-24
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Expires: 1998-01-16
Abstract
Abstract Artificial membrane for wound-dressings composed of two polypeptide layers, one of which at least, the inside layer which contacts the wound, is biologically resorbable and the outside layer has an asymmetric structure permeable to water and to drug solutions but pratically impervious to outside pathogenic agents. The inside layer, at least, is constituted from biodegradable copolymers of amino-acids and -diacids of which the -COOH functions are partially esterified with mono and/or di-ols.
Inventors
- 👤 Daniel Bichon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:36
CPC Classifications
B; B32; B32B; B32B3/00; B32B3/26; B32B3/266; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/32; A61L15/42; A61L15/64; A61L27/00; A61L27/50; A61L27/60; B32B27/00; B32B27/06; B32B27/08; B32B27/28; B32B7/00; B32B7/04; B32B7/12; A61F; A61F13/00; A61F2013/00361; A61F2013/00365; A61F2013/00519; A61F2013/00527; B32B2305/00; B32B2305/02; B32B2305/026; B32B2307/00; B32B2307/70; B32B2307/716; B32B2307/7163; B32B2307/724; B32B2307/728; B32B2535/00; Y; Y10; Y10S; Y10S602/00; Y10S602/90; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249961; Y10T428/31504; Y10T428/31725
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
141 words
Synthetic membrane or skin containing poly-aminoacids usable for wound-dressings consisting of two integral layers of which at least one is resorbable by the body, the first internal layer being directly applied to the wound and the second layer constituting an external protection thereof, characterized by the fact that the second layer is formed from a porous semi-permeable membrane or film having an asymmetric structure, that is having pores of decreasing size when going from the inside layer to the outside one, which ensures the free penetration of air, water and low molecular weight substances but prevents the entrance of external pathogenic germs, and by the fact that the first layer is essentially formed of a hydrophilic, non-toxic, bio-degradable membrane or tissue consisting substantially of a pluri-cellular, spongy and fluid permeable material selected from polymers and copolymers of α-aminoacids and esters thereof.
Claim 2
Dependent Claim
141 words
Synthetic membrane or skin containing poly-aminoacids usable for wound-dressings consisting of two integral layers of which at least one is resorbable by the body, the first internal layer being directly applied to the wound and the second layer constituting an external protection thereof, characterized by the fact that the second layer is formed from a porous semi-permeable membrane or film having an asymmetric structure, that is having pores of decreasing size when going from the inside layer to the outside one, which ensures the free penetration of air, water and low molecular weight substances but prevents the entrance of external pathogenic germs, and by the fact that the first layer is essentially formed of a hydrophilic, non-toxic, bio-degradable membrane or tissue consisting substantially of a pluri-cellular, spongy and fluid permeable material selected from polymers and copolymers of α-aminoacids and esters thereof.
Claim 3
Dependent Claim
19 words
The membrane of claim 1, wherein said first layer comprises a copolymer of L-leucine and L-glutamic acid partially esterified.
Claim 4
Dependent Claim
33 words
The membrane of claims 2 wherein the copolymer of said first layer is cross-linked by means of ester bridges resulting from an esterification of the --COOH functions with a diol, e.g. polyoxyethyleneglycol 300.
Claim 5
Dependent Claim
28 words
The membrane of claim 3 wherein the copolymer contains at least 10% and no more than 50 mole % of L-leucine, the rest being the said L-glutamic acid.
Claim 6
Dependent Claim
11 words
The membrane of claim 3, wherein said diol is polyoxyethyleneglycol 300.
Claim 7
Dependent Claim
19 words
The membrane of claim 1, wherein said first layer comprises a copolymer of L-leucine and L-aspartic acid partially esterified.
Claim 8
Dependent Claim
29 words
The membrane of claim 6 wherein the copolymer of said first layer is cross-linked by means of ester bridges resulting from esterification of the --COOH functions with a diol.
Claim 9
Dependent Claim
11 words
The membrane of claim 7, wherein said diol is polyoxyethyleneglycol 300.
Claim 10
Dependent Claim
28 words
The membrane of claim 7 wherein the copolymer contains at least 10% and no more than 50 mole % of L-leucine, the rest being the said aspartic acid.
Claim 11
Dependent Claim
13 words
The membrane of claim 1, wherein said first layer is 0,5-3 mm thick.
Claim 12
Dependent Claim
24 words
The membrane of claim 1, wherein the second layer comprises a material selected from film-making polymers and copolymers of α-aminoacids and alkyl esters thereof.
Claim 13
Dependent Claim
17 words
The membrane of claim 11, wherein said second layer comprises a copolymer of L-leucine and a γ-alkyl-L-glutamate.
Claim 14
Dependent Claim
10 words
The membrane of claim 12 wherein the γ-alkyl-L-glutamate is γ-methyl-L-glutamate.
Claim 15
Dependent Claim
18 words
The membrane of claim 11, wherein said second layer copolymer comprises equal mole proportions of each starting monomer.
Claim 16
Dependent Claim
13 words
The membrane of claim 11, wherein said second layer is about 30-100μ thick.
Claim 17
Dependent Claim
21 words
The use of the synthetic membrane of claim 1 as a wound-dressing that is resorbable at least in part in situ.
Claim 18
Dependent Claim
55 words
A method for manufacturing the synthetic membrane of claim 1, which comprises applying on the first layer, after said first layer has been formed, the second layer or the substance of said second layer in a manner such that the surface of the latter which has the coarser porosity will adhere to the first layer.
Claim 19
Dependent Claim
70 words
The method of claim 14, which comprises depositing on one of the surfaces of the first layer a glueing solution containing a N-carboxyanhydride of an aminoacid dissolved in an organic solvent, stacking the second layer, coarser porous side down, over the surface of the first layer coated with the adhesive with application of slight pressure and allowing the complete composite to dry until all solvent of the adhesive has evaporated.
Claim 20
Dependent Claim
15 words
The method of claim 18, wherein the aminoacid is glycine and the solvent is ethylacetate.
Claim 21
Dependent Claim
52 words
The method of claim 17, which comprises depositing on the first layer a solution of the copolymer of the second layer dissolved in a water-soluble solvent and treating the resulting composite with ice-water for a time sufficient for the solvent to fully diffuse into the water and the second layer to solidify.
References Cited (Backward Citations)
US3875937A
Cited
US3867520A
Cited
FR2150695A1
Cited
US3849238A
Cited
US3978266A
Cited
US3978855A
Cited
US4060081A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-07-23 | 1983-01-22 | 1983-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-23 | 1987-01-22 | 1987-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-23 | 1991-01-22 | 1991-07-24 | $7700.00 | Window Closed / Lapsed |