US4425434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Immobilization of biologically active substances
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1981-08-11
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Granted: 1984-01-10
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Expires: 2001-08-11
Abstract
Abstract The invention relates to a method for the preparation of discrete particles containing a biologically active substance comprising discrete particles of support material having immobilized in the pores thereof a biologically active substance (e.g. an enzyme). The method includes precipitating a biologically active substance in the pores of the particles of support material, by use of a precipitating agent comprising or including a water miscible organic liquid, and treating the biologically active substance precipitated in the pores to cause cross-linking so as to immobilize biologically active substance in the pores of the particles or porous support material.
Inventors
- 👤 Alan Rosevear
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:55
CPC Classifications
C; C12; C12N; C12N11/00; C12N11/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
286 words
A method for the preparation of discrete particles containing a biologically active substance, comprising discrete particles of porous support material having a biologically active substance immobilised in the pores thereof, which method comprises selecting discrete particles of a porous support material having a pore size and structure that permits entry of a solution containing biologically active substance, said particles also being selected to have a particle size suitable for use in a column or fluidised bed reactor, introducing a solution containing biologically active substance into the pores of said particles of porous support material substantially to fill the pore volume of said particles of porous support material, treating the solution introduced into the pores with a precipitating agent and a cross-linking agent, said treatment with a precipitating agent precipitating said biologically active substance so as to retain said biologically active substance in the pores of the particles of porous support material and thereby hold the biologically active substance available for cross-linking by said cross-linking agent, said precipitating agent being selected from the group consisting of tannic acid in ethanol, tannic acid in acetone, tannic acid in water/isopropanol, a synthetic polyphenol in acetone, a synthetic polyphenol in water/acetone, tannic acid in water/acetone and acetone, and said treatment with a cross-linking agent cross-linking the biologically active substance precipitated in the pores of the porous support material so as to immobilise biologically active substance in the pores of the particles of porous support material, said introduction of solution containing biologically active substance and said precipitating and cross-linking being conducted so as to provide a major proportion of the immobilised biologically active substance in the pores of, rather than on the external surface of, the particles of porous support material.
Claim 2
Independent Claim
286 words
A method for the preparation of discrete particles containing a biologically active substance, comprising discrete particles of porous support material having a biologically active substance immobilised in the pores thereof, which method comprises selecting discrete particles of a porous support material having a pore size and structure that permits entry of a solution containing biologically active substance, said particles also being selected to have a particle size suitable for use in a column or fluidised bed reactor, introducing a solution containing biologically active substance into the pores of said particles of porous support material substantially to fill the pore volume of said particles of porous support material, treating the solution introduced into the pores with a precipitating agent and a cross-linking agent, said treatment with a precipitating agent precipitating said biologically active substance so as to retain said biologically active substance in the pores of the particles of porous support material and thereby hold the biologically active substance available for cross-linking by said cross-linking agent, said precipitating agent being selected from the group consisting of tannic acid in ethanol, tannic acid in acetone, tannic acid in water/isopropanol, a synthetic polyphenol in acetone, a synthetic polyphenol in water/acetone, tannic acid in water/acetone and acetone, and said treatment with a cross-linking agent cross-linking the biologically active substance precipitated in the pores of the porous support material so as to immobilise biologically active substance in the pores of the particles of porous support material, said introduction of solution containing biologically active substance and said precipitating and cross-linking being conducted so as to provide a major proportion of the immobilised biologically active substance in the pores of, rather than on the external surface of, the particles of porous support material.
Claim 3
Dependent Claim
44 words
A method as claimed in claim 1 wherein the precipitation and cross-linking are carried out sequentially by treating the solution of the biologically active substance in the pores with the precipitating agent and then treating the precipitated biologically active substance with the cross-linking agent.
Claim 4
Dependent Claim
61 words
A method as claimed in claim 2 wherein introducing of the solution containing biologically active substance into the pores of the particles is carried out by soaking the particles in a concentrated solution of biologically active substance to introduce solution into the pores of the porous support material prior to subsequent treatment with the precipitating agent and with a cross-linking agent.
Claim 5
Dependent Claim
28 words
A method as claimed in claim 1 wherein the treatment with a precipitating agent and a cross-linking agent is conducted simultaneously and said precipitating occurs before said cross-linking.
Claim 6
Dependent Claim
34 words
A method as claimed in claim 1, wherein the biologically active substance is immobilised by being treated with a cross-linking agent selected from the group consisting of glutaraldehyde, formaldehyde, diethylpyrocarbonate, glyoxal and bis-diazonium salt.
Claim 7
Dependent Claim
40 words
A method as claimed in claim 1 wherein the particles of support material are selected from the group consisting of porous alumina spheroids, porous zirconia spheroids, controlled pore glass, crushed thermalite block, alumino-silicate catalyst particles, and a porous natural earth.
Claim 8
Dependent Claim
15 words
A method as claimed in claim 1 wherein the biologically active substance is an enzyme.
Claim 9
Dependent Claim
26 words
A method as claimed in claim 7 wherein the enzyme is amyloglucosidase, lactase, α-amylase, chymotrypsin, trypsin, urease, glucose oxidase, lipoxidase, glucose isomerase, papain, neutrase and pronase.
Claim 10
Dependent Claim
21 words
A method as claimed in claim 1 wherein surplus precipitated and cross-linked biologically active substance outside of the particles is removed.
Claim 11
Dependent Claim
24 words
Discrete particles of a porous support material having immobilised thereon a biologically active substance, when prepared by a method as claimed in claim 1.
Claim 12
Independent Claim
154 words
A method for the preparation of discrete particles containing a biologically active substance comprising soaking particles of porous support material in a concentrated solution of biologically active substance subjecting said soaked particles to freeze-drying to retain biologically active substance in the particles of porous support material, introducing further biologically active substance into the pores of the particles by immersion in a concentrated solution of biologically active substance, precipitating said further introduced biologically active substance by use of a precipitating agent selected from the group consisting of a water miscible organic liquid and a precipitating agent including a water miscible organic liquid for improving the precipation, and cross-linking biological active substance retained in the pores by said freeze drying and said precipitation by treatment with a cross-linking agent under conditions such that substantially no retained substance goes into solution, to immobilize the biologically active substance in the pores of the particles of the support material.
Claim 13
Independent Claim
154 words
A method for the preparation of discrete particles containing a biologically active substance comprising soaking particles of porous support material in a concentrated solution of biologically active substance subjecting said soaked particles to freeze-drying to retain biologically active substance in the particles of porous support material, introducing further biologically active substance into the pores of the particles by immersion in a concentrated solution of biologically active substance, precipitating said further introduced biologically active substance by use of a precipitating agent selected from the group consisting of a water miscible organic liquid and a precipitating agent including a water miscible organic liquid for improving the precipation, and cross-linking biological active substance retained in the pores by said freeze drying and said precipitation by treatment with a cross-linking agent under conditions such that substantially no retained substance goes into solution, to immobilize the biologically active substance in the pores of the particles of the support material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |