US6203845B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dehydrated hydrogels
Assignee: Innovative Technologies Ltd
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Filing: 1997-04-21
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Granted: 2001-03-20
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Expires: 2017-04-21
Abstract
Abstract A method of producing a dehydrated hydrogel comprises dispensing fibers into an aqueous solution of a hydrogel precursor material incorporating a plasticiser, the fibers incorporating cations which are capable of cross-linking said precursor material to form a hydrogel, and freeze drying the mixture thus produced to provide a dehydrated hydrogel which incorporates said fibers, the dehydrated hydrogel being cross-linked by said cations.
Inventors
- 👤 Yimin Qin
- 👤 Keith Dennis Gilding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:49
CPC Classifications
A; A61; A61L; A61L26/00; A61L26/0061; A61L26/008; A61L15/00; A61L15/16; A61L15/22; A61L15/28; A61L15/42; A61L15/60; A61L26/0009; A61L26/0023
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
62 words
A method of producing a dehydrated hydrogel comprising dispersing fibres into an aqueous solution of a hydrogel precursor material incorporating a plasticiser, the fibres incorporating cations which are capable of cross-linking said precursor material to form a hydrogel, and freeze drying the mixture thus produced to provide a dehydrated hydrogel which incorporates said fibres, the dehydrated hydrogel being cross-linked by said cations.
Claim 2
Independent Claim
62 words
A method of producing a dehydrated hydrogel comprising dispersing fibres into an aqueous solution of a hydrogel precursor material incorporating a plasticiser, the fibres incorporating cations which are capable of cross-linking said precursor material to form a hydrogel, and freeze drying the mixture thus produced to provide a dehydrated hydrogel which incorporates said fibres, the dehydrated hydrogel being cross-linked by said cations.
Claim 3
Dependent Claim
45 words
A method as claimed in claim 1 wherein the hydrogel precursor material is selected from sodium alginate, sodium carboxymethyl cellulose, sodium pectinate, sodium O-carboxymethyl chitosan (OCC), sodium N,O-carboxymethyl chitosan (NOCC), sodium polyacrylate, and naturally occurring gums and synthetic polymers containing pendant carboxylic acid groups (hummectants).
Claim 4
Dependent Claim
24 words
A method as claimed in claim 1 wherein the fibres contain Ca 2+ , Zn 2+ and/or cations which also act as enzyme cofactors.
Claim 5
Dependent Claim
14 words
A method as claimed in claim 1 wherein the fibres are calcium alginate fibres.
Claim 6
Dependent Claim
15 words
A method as claimed in claim 2 wherein the hydrogel precursor material is sodium alginate.
Claim 7
Dependent Claim
14 words
A method as claimed in claim 5 wherein the fibres are calcium alginate fibres.
Claim 8
Dependent Claim
55 words
A method as claimed in claim 1 wherein the dehydrated hydrogel comprises 15 to 40% by weight of fibres, 10 to 35% by weight of polymer forming the hydrogel and 5 to 75% by weight of plasticiser, the percentages being based on the total weight of the fibres, polymer forming the hydrogel, and the plasticiser.
Claim 9
Dependent Claim
22 words
A method as claimed in claim 1 wherein the ratio by weight of the fibres to that of the polymer is 1.5-3:1.
Claim 10
Dependent Claim
28 words
A method as claimed in claim 1 wherein the dehydrated hydrogel contain less the 20% by weight of water based on the total weight of the dehydrated hydrogel.
Claim 11
Dependent Claim
26 words
A method as claimed in claim 1 wherein the fibres have a length of 1 to 80 mm and a thickness of 10 to 50 microns.
References Cited (Backward Citations)
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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) | 2004-03-19 | 2004-09-18 | 2005-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-19 | 2008-09-18 | 2009-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-19 | 2012-09-18 | 2013-03-20 | $7700.00 | Window Closed / Lapsed |