US5232984A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Biocompatible microcapsules
Assignee: The University of Texas System
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Filing: 1991-08-05
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Granted: 1993-08-03
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Expires: 2011-08-05
Abstract
Abstract Biocompatible microcapsules useful for transplanting foreign material into an animal body, and the method of their production, are described, wherein the microcapsules contain an outermost layer of water soluble non-ionic polymers such as PEO to create resistance to cell adhesion on the surface of the microcapsules.
Inventors
- 👤 Jeffrey A. Hubbell
- 👤 Amarpreet S. Sawhney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:56
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5005; A61K9/5021; A61K9/5031; A61K47/00; A61K47/50; A61K47/51; A61K47/56; A61K47/59; A61K47/60; A61K47/62; A61K47/64; A61K47/645; A61K47/69; A61K47/6921; A61K47/6925; A61K9/5073
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
64 words
A method for grafting water soluble non-ionic polymers to polyamine or polyimine polycationic polymers comprising: a) activating the reactive groups capable of being covalently linked to a coupling agent on the water soluble non-ionic polymers by using an activation agent selected from the group consisting of carbodiimidazole, sulfonyl chlorides and chlorocarbonates, and b) coupling the activated water soluble non-ionic polymers to the polycationic polypeptides.
Claim 2
Independent Claim
64 words
A method for grafting water soluble non-ionic polymers to polyamine or polyimine polycationic polymers comprising: a) activating the reactive groups capable of being covalently linked to a coupling agent on the water soluble non-ionic polymers by using an activation agent selected from the group consisting of carbodiimidazole, sulfonyl chlorides and chlorocarbonates, and b) coupling the activated water soluble non-ionic polymers to the polycationic polypeptides.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the reactive groups are selected from the group consisting of hydroxyls, carboxyls, diols, aldehydes, amines, and thiols.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein the non-ionic water soluble polymers are selected from the group consisting of poly(ethylene oxide), poly(vinyl pyrrolidone), poly(ethyl oxazoline), poly(vinyl alcohol) and polysaccharides.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the polycationic polymers are selected from the group consisting of polylysine, polyornithine, polyethyleneimine, and polyallylamine.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein the sulfonyl chloride is trifyl chloride.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the sulfonyl chloride is tresyl chloride.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein the sulfonyl chloride is tosyl chloride.
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein the sulfonyl chloride is pentafluorobenzenesulfonyl chloride.
Claim 10
Dependent Claim
11 words
The method of claim 1 wherein the chlorocarbonate is p-nitrophenyl chlorocarbonate.
Claim 11
Dependent Claim
12 words
The method of claim 1 wherein the chlorocarbonate is 2,4,5 trichlorophenyl chlorocarbonate.
Claim 12
Dependent Claim
11 words
The method of claim 1 wherein the chlorocarbonate is N-hydroxysuccinamide chlorocarbonate.
References Cited (Backward Citations)
US3857931A
Cited
US4330440A
Cited
US4496689A
Cited
US4745160A
Cited
US4970273A
Cited
US4753983A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-02 | 1997-02-01 | 1997-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-02 | 2001-02-01 | 2001-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-02 | 2005-02-01 | 2005-08-03 | $7700.00 | Window Closed / Lapsed |