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US5648252A Expired / Lapsed US ⏱️ 0.0 years remaining

Supported polyionic hydrogels containing biologically active material

Assignee: Israel Fiber Institute
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Filing: 1995-03-22
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Granted: 1997-07-15
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Expires: 2015-03-22
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Abstract

Abstract A supported polyionic hydrogel containing biologically active material is epared by impregnating into a porous support material a solution of anionic polysaccharide, a solution of cationic polysaccharide and a biologically active material. The anionic polysaccharide and the cationic polysaccharide react with each other to form a hydrogel containing the biologically active material. The hydrogel may be dried such as by lyophilization. The biologically active material can be in either polysaccharide solution or in another solution impregnated into the porous support material. A paper material or a textile material may be used as the porous support material. Preferably, the anionic polysaccharide is xanthan, dicarboxystarch or dicarboxycellulose and the cationic polysaccharide is chitosan. Especially preferred is a hydrogel formed from xanthan and chitosan. Biologically active materials in the hydrogel can be enzymes, antibody-producing cells or water-soluble drugs such as the antimicrobial agent, chlorohexidine.

Inventors

  • 👤 Severian Dumitriu
  • 👤 Itzhak Kahane
  • 👤 Hilda Guttmann

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 07:19
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/02; C12N11/04; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; C12N5/00; C12N5/0068; C12N2533/00; C12N2533/70; C12N2533/72; Y; Y10; Y10S; Y10S530/00; Y10S530/81; Y10S530/812; Y10S530/813; Y10S530/814

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 109 words
A supported polyionic hydrogel containing a biologically active material formed by a method comprising the steps: a) impregnating into a porous support material a solution of an anionic polysaccharide selected from the group consisting of xanthan, dicarboxystarch and dicarboxycellulose, and b) impregnating into the porous support material from a) a chitosan solution, whereby said anionic polysaccharide and said chitosan react with each other while in contact with and impregnated into said porous support to produce a polyionic hydrogel impregnated into said porous support material, said biologically active material being in said anionic polysaccharide solution or said chitosan solution or in a separate solution impregnated into said porous support material.
Claim 2
Dependent Claim 109 words
A supported polyionic hydrogel containing a biologically active material formed by a method comprising the steps: a) impregnating into a porous support material a solution of an anionic polysaccharide selected from the group consisting of xanthan, dicarboxystarch and dicarboxycellulose, and b) impregnating into the porous support material from a) a chitosan solution, whereby said anionic polysaccharide and said chitosan react with each other while in contact with and impregnated into said porous support to produce a polyionic hydrogel impregnated into said porous support material, said biologically active material being in said anionic polysaccharide solution or said chitosan solution or in a separate solution impregnated into said porous support material.
Claim 3
Dependent Claim 14 words
The supported polyionic hydrogel according to claim 1, wherein said anionic polysaccharide is xanthan.
Claim 4
Dependent Claim 18 words
The supported polyionic hydrogel according to claim 1, wherein the biologically active material is a pharmaceutically active compound.
Claim 5
Dependent Claim 15 words
The supported polyionic hydrogel according to claim 3, wherein said compound is a water-soluble drug.
Claim 6
Dependent Claim 16 words
The supported polyionic hydrogel according to claim 4, wherein said water-soluble drug is an antimicrobial agent.
Claim 7
Dependent Claim 14 words
The supported polyionic hydrogel according to claim 5, wherein said antimicrobial agent is chlorohexidine.
Claim 8
Dependent Claim 16 words
The supported polyionic hydrogel according to claim 1, wherein said biologically active material is an enzyme.
Claim 9
Dependent Claim 17 words
The supported polyionic hydrogel according to claim 1, wherein said biologically active material is antibody producing cells.
Claim 10
Dependent Claim 20 words
The supported polyionic hydrogel according to claim 1, wherein said polyionic hydrogel impregnated in said porous support material is dehydrated.
Claim 11
Dependent Claim 27 words
The supported polyionic hydrogel according to claim 1, wherein said porous support material is selected from the group consisting of a paper material and a textile material.

References Cited (Backward Citations)

US3975350A Cited
US4452892A Cited
US4578351A Cited
US4744933A Cited
US5116747A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-07-14 2001-01-13 2001-07-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-07-14 2005-01-13 2005-07-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-07-14 2009-01-13 2009-07-15 $7700.00 Window Closed / Lapsed

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