US4060081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer membrane useful as synthetic skin
Assignee: Massachusetts Institute of Technology
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Filing: 1975-07-15
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Granted: 1977-11-29
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Expires: 1995-07-15
Abstract
Abstract A multilayer membrane, which is useful as synthetic skin, is disclosed herein. A first layer is formed from a material which does not provoke an immune response and which is also insoluble and nondegradable in the presence of body fluids and/or body enzymes. Preferred materials for the first layer are crosslinked composites of collagen and a mucopolysaccharide. A second layer is formed from a nontoxic material which controls the moisture flux of the overall membrane to about 0.1 to 1 mg./cm 2 /hr. Suitable materials for the second layer include synthetic polymers such as silicone resins, polyacrylate or polymethacrylate esters or their copolymers, and polyurethanes.
Inventors
- 👤 Ioannis V. Yannas
- 👤 John F. Burke
- 👤 Philip L. Gordon
- 👤 Chor Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:11
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/14; A61L27/22; A61L27/24; A61F; A61F2/00; A61F2/02; A61F2/10; A61F2/105; A61L15/00; A61L15/16; A61L15/22; A61L15/225; A61L27/50; A61L27/60; A61F2310/00; A61F2310/00005; A61F2310/00365; Y; Y10; Y10S; Y10S128/00; Y10S128/08
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
57 words
A multilayer membrane, comprising: a. a first layer formed from a crosslinked collagen-mucopolysaccharide composite containing at least about 0.5% by weight mucopolysaccharide; and, b. a moisture transmission control layer formed from a nontoxic material, said moisture transmission control layer providing said multilayer membrane with a moisture flux of from about 0.1 to about 1 mg/cm 2 /hr.
Claim 2
Dependent Claim
57 words
A multilayer membrane, comprising: a. a first layer formed from a crosslinked collagen-mucopolysaccharide composite containing at least about 0.5% by weight mucopolysaccharide; and, b. a moisture transmission control layer formed from a nontoxic material, said moisture transmission control layer providing said multilayer membrane with a moisture flux of from about 0.1 to about 1 mg/cm 2 /hr.
Claim 3
Dependent Claim
18 words
A multilayer membrane of claim 1 wherein said moisture transmission control layer is formed form a natural polymer.
Claim 4
Dependent Claim
18 words
A multilayer membrane of claim 1 wherein said moisture transmission control layer is formed from a synthetic polymer.
Claim 5
Dependent Claim
14 words
A multilayer membrane of clam 3 wherein said collagen-mucopolysaccharide composite contains a sulfate-containing mucopolysaccharide.
Claim 6
Dependent Claim
14 words
A multilayer membrane of clam 3 wherein said collagen-mucopolysaccharide composite contains a sulfate-containing mucopolysaccharide.
Claim 7
Dependent Claim
23 words
A multilayer membrane of claim 4 wherein said collagen-mucopolysaccharide composite contains from about 6% to about 12% by weight of said sulfate-containing mucopolysaccharide.
Claim 8
Dependent Claim
25 words
A multilayer membrane of claim 5 wherein said sulfate-containing mucopolysaccharide is selected from chondroitin 6-sulfate, chondroitin 4-sulfate, heparin, heparan sulfate, keratan sulfate or dermatan sulfate.
Claim 9
Dependent Claim
24 words
A multilayer membrane of claim 6 wherein said collagen-mucopolysaccharide composite is crosslinked to an M c value of between about 800 and about 60,000.
Claim 10
Dependent Claim
13 words
A multilayer membrane of claim 7 wherein said sulfate-containing mucopolysaccharide is chondroitin 6-sulfate.
Claim 11
Dependent Claim
28 words
A multilayer membrane of claim 8 wherein said moisture transmission control layer is formed from a synthetic polymer selected from silicone resins, polyacrylate esters, polymethacrylate esters and polyurethanes.
Claim 12
Dependent Claim
28 words
A multilayer membrane of claim 4 wherein said moisture transmission control layer is formed from a synthetic polymer selected from silicone resins, polyacrylate esters, polymethacrylate esters and polyurethanes.
Claim 13
Dependent Claim
18 words
A multilayer membrane of claim 8 wherein said moisture transmission control layer is formed from a silicone resin.
Claim 14
Dependent Claim
30 words
A multilayer membrane of claim 11 wherein said moisture transmission control layer provides said multilayer membrane with a moisture flux of from about 0.3 to about 0.5 mg/cm 2 /hr.
Claim 15
Dependent Claim
18 words
A multilayer membrane of claim 12 having an overall thickness of from about 25 to about 100 mils.
Claim 16
Dependent Claim
18 words
A multilayer membrane of claim 1 having an overall thickness of from about 25 to about 100 mils.
Claim 17
Dependent Claim
39 words
Synthetic skin comprising a first layer formed from a crosslinked collagen-mucopolysaccharide composite bonded to a nontoxic moisture transmission control layer which provides said synthetic skin with a moisture flux of from about 0.1 to about 1 mg/cm 2 /hr.
Claim 18
Dependent Claim
39 words
Synthetic skin comprising a first layer formed from a crosslinked collagen-mucopolysaccharide composite bonded to a nontoxic moisture transmission control layer which provides said synthetic skin with a moisture flux of from about 0.1 to about 1 mg/cm 2 /hr.
Claim 19
Dependent Claim
15 words
Synthetic skin of claim 15 wherein said moisture transmission control layer is a synthetic polymer.
Claim 20
Dependent Claim
20 words
Synthetic skin of claim 16 wherein said synthetic polymer is selected from silicone resins, polyacrylate esters, polymethacrylate esters and polyurethanes.
Claim 21
Dependent Claim
13 words
Synthetic skin of claim 16 wherein said synthetic polymer is a silicone resin.
Claim 22
Dependent Claim
39 words
Synthetic skin of claim 18 wherein said collagen-mucopolysaccharide composite material contains from about 6% to about 12% of a sulfate-containing mucopolysaccharide and wherein said composite is crosslinked to an M c value of from about 5000 to about 10,000.
Claim 23
Dependent Claim
12 words
Synthetic skin of claim 19 wherein said sulfate-containing mucopolysaccharide is chondroitin 6-sulfate.
Claim 24
Dependent Claim
17 words
Synthetic skin of clam 20 having an overall thickness of from about 25 to about 100 mils.
Claim 25
Dependent Claim
17 words
Synthetic skin of clam 20 having an overall thickness of from about 25 to about 100 mils.
Claim 26
Dependent Claim
17 words
Synthetic skin of claim 15 having an overall thickness of from about 25 to about 100 mils.
Claim 27
Dependent Claim
35 words
Synthetic skin comprising a multilayer membrane having a first layer formed from a crosslinked collagen-mucopolysaccharide composite and a moisture control layer which provides the multilayer membrane with a moisture flux substantially equal to normal skin.
Claim 28
Dependent Claim
35 words
Synthetic skin comprising a multilayer membrane having a first layer formed from a crosslinked collagen-mucopolysaccharide composite and a moisture control layer which provides the multilayer membrane with a moisture flux substantially equal to normal skin.
Claim 29
Dependent Claim
81 words
A multilayer membrane, useful as synthetic skin, comprising: a. a first layer formed from a crosslinked collagen-mucopolysaccharide composite material which: (1) has controllable degradability in the presence of body enzymes; (2) has controllable solubility in the presence of body fluids; (3) is substantially nonimmunogenic upon grafting or implantation; and, (4) provokes no substantial foreign body response upon grafting or implantation; and, b. a moisture transmission control layer which provides the multilayer membrane with a moisture flux substantially equal to normal skin.
Claim 30
Dependent Claim
81 words
A multilayer membrane, useful as synthetic skin, comprising: a. a first layer formed from a crosslinked collagen-mucopolysaccharide composite material which: (1) has controllable degradability in the presence of body enzymes; (2) has controllable solubility in the presence of body fluids; (3) is substantially nonimmunogenic upon grafting or implantation; and, (4) provokes no substantial foreign body response upon grafting or implantation; and, b. a moisture transmission control layer which provides the multilayer membrane with a moisture flux substantially equal to normal skin.
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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) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |