Patent US4749620A successfully refreshed from Google Patents.
US4749620A
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US
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Encapsulated active material system
Assignee: Massachusetts Institute of Technology
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Filing: 1985-09-18
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Granted: 1988-06-07
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Expires: 2005-09-18
Abstract
Abstract Capsules are formed herein a liquified core while avoiding capsule core gelation by adding drops of a solution of either an anionic polymer composition or a cationic polymer composition to a solution of an ionic polymer of opposite charge. The drops contain an active ingredient such as a cell or microorganism capable of producing a biologically active product or can contain a biological or chemical composition. The interface of the ionic polymers form a permeable membrane surrounding the liquid drops.
Inventors
- 👤 ChoKyun Rha
- 👤 Dolores Rodriguez-Sanchez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:39
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/50; A61K9/5089; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1652; A61K9/5005; A61K9/5021; A61K9/5036; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
91 words
A capsule comprising a polymeric membrane surrounding a liquid core wherein said membrane is formed by the interaction of at least one anionic polymer with at least one cationic polymer wherein molecular chains comprising said anionic polymer and said cationic polymer are oriented substantially within said membrane so that said polymers are free to react with each other along the entire chain lengths of said polymers where said polymers come into reactive contact with each other and wherein said cationic polymer forms the inner surface of said membrane adjacent liquid core.
Claim 2
Dependent Claim
91 words
A capsule comprising a polymeric membrane surrounding a liquid core wherein said membrane is formed by the interaction of at least one anionic polymer with at least one cationic polymer wherein molecular chains comprising said anionic polymer and said cationic polymer are oriented substantially within said membrane so that said polymers are free to react with each other along the entire chain lengths of said polymers where said polymers come into reactive contact with each other and wherein said cationic polymer forms the inner surface of said membrane adjacent liquid core.
Claim 3
Dependent Claim
13 words
The capsule of claim 1 wherein said liquid core contains a living cell.
Claim 4
Dependent Claim
10 words
The capsule of claim 2 wherein said cell is hybridoma.
Claim 5
Dependent Claim
12 words
The capsule of claim 2 wherein said cell is a lymphocyte cell.
Claim 6
Dependent Claim
26 words
The capsule of any one of claims 1, 2, 3 or 4 wherein said anionic polymer is selected from the group consisting of alginate and carragenan.
Claim 7
Dependent Claim
26 words
The capsule of any one of claims 1, 2, 3 or 4 wherein said cationic polymer is selected from the group consisting of chitosan and polylysive.
Claim 8
Dependent Claim
36 words
The capsule of any one of claims 2, 3 or 4 which includes a second membrane formed by cross-linking the anionic polymer to the anionic polymer portion of said polymeric membrane with a divalent metal ion.
Claim 9
Dependent Claim
48 words
The capsule of any one of claims 2, 3 or 4 which includes a second alginate membrane formed by cross-linking the anionic polymer to the anionic polymer portion of said polymeric membrane with a divalent metal ion selected from the group consisting of calcium, barium and mixtures thereof.
References Cited (Backward Citations)
US3994827A
Cited
US4407957A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |