EP0034304A2
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EP
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Method of immobilizing an enzyme in a bundle of cellulosic fibres for a fibre-bundle dialyzer for purifying blood
Assignee: Sorin Biomedica SpA
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Filing: 1981-02-05
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Granted: —
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Expires: 2001-02-05
Abstract
Abstract The object of the method is to immobilize a desired enzyme on the lumen surfaces of the dialyzer fibres typically having an inner diameter of 200-300 microns and wall thickness of 10-20 microns, without prejudice to the chemico-physical, dialyzing and bio-compatibility properties of the fibres. The enzyme is anchored directly or indirectly through covalent bonds upon activation of the lumen surfaces by circulation through the lumens of an aqueous solution of sodium periodate at a concentration of 0.7 - 21 mg/mi, at a circulation rate of 300-500 mm 3 /minute referred to 1 mm 2 of cross-sectional area of the lumen, at 15-30°C for a time not exceeding 70 minutes.
Inventors
- 👤 Lanfranco Callegaro
- 👤 Antonio Boniolo
- 👤 Ennio Denti
- 👤 Umberto Rosa
- 👤 Valdano Rossi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 19:28
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/02; A; A61; A61M; A61M1/00; A61M1/36; A61M1/3679; C; C12; C12N; C12N11/00; C12N11/02; C12N11/10; C12N11/12; F; F16; F16L; F16L27/00; F16L27/02; F16L27/04
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
154 words
Method of immobilizing an enzyme in a bundle of cellulosic hollow fibres for a fibre-bundle dialyzer for purifying blood, by a process comprising a stage (a) of activating a cellulosic material by means of an oxidizing agent, a subsequent stage (b) of removing excess agent by washing, and a still subsequent stage (c) of directly or indirectly anchoring the enzymes to the activated material through covalent linkages, characterized in that, for the purpose of anchoring the enzymes selectively to the lumen surfaces of the fibres, the activating stage (a) is effected by circulating through the lumen of the fibres in the bundle an aqueous solution of sodium periodate at a concentration of 0.7 - 21 mg/ml, at a circulation rate of 300 - 500 mm 3 /minute referred to 1 mm 2 of cross-sectional area of the lumen, at a temperature of 15 - 30°C for a period of time not exceeding 70 minutes.
Claim 2
Dependent Claim
154 words
Method of immobilizing an enzyme in a bundle of cellulosic hollow fibres for a fibre-bundle dialyzer for purifying blood, by a process comprising a stage (a) of activating a cellulosic material by means of an oxidizing agent, a subsequent stage (b) of removing excess agent by washing, and a still subsequent stage (c) of directly or indirectly anchoring the enzymes to the activated material through covalent linkages, characterized in that, for the purpose of anchoring the enzymes selectively to the lumen surfaces of the fibres, the activating stage (a) is effected by circulating through the lumen of the fibres in the bundle an aqueous solution of sodium periodate at a concentration of 0.7 - 21 mg/ml, at a circulation rate of 300 - 500 mm 3 /minute referred to 1 mm 2 of cross-sectional area of the lumen, at a temperature of 15 - 30°C for a period of time not exceeding 70 minutes.
Claim 3
Dependent Claim
14 words
Method according to claim 1, wherein the periodate concentration does not exceed 5 mg/ml.
Claim 4
Dependent Claim
14 words
3 . Method according to claim 1, wherein the periodate concentration is 1 mg/ml.
Claim 5
Dependent Claim
18 words
Method according to claim 1, wherein the circulation rate is 350 - 480 mm 3 /min/mm 2 .
Claim 6
Dependent Claim
17 words
Method according to claim 4, wherein the circulation - rate is 400 mm 3 /min/mm 2 .
Claim 7
Dependent Claim
21 words
Method according to claim 1, wherein the temperature is from 18°C to 25°C and the time period is of 60 minutes.
Claim 8
Dependent Claim
32 words
Method according to any of the preceding claims 1-6, wherein the lumen diameter of the fibres is from 200 to 300 microns and the wall thickness of the fibres is 10-20 microns.
Claim 9
Dependent Claim
16 words
Method according to any of the preceding claims 1-7, wherein the enzyme is a glutathione transferase.
Claim 10
Dependent Claim
14 words
Method according to any of the preceding claims 1-7, wherein the enzyme is creatininase.
Claim 11
Dependent Claim
14 words
Method according to any of the preceding claims 1-7, wherein the enzyme is asparaginase.
Claim 12
Dependent Claim
14 words
Method according to any of the preceding claims 1-7, wherein the enzyme is beta-galactoxydase.
Claim 13
Dependent Claim
14 words
Method according to any of the preceding claims 1-7, wherein the enzyme is uricase.
Claim 14
Dependent Claim
14 words
Method according to any of the preceding claims 1-7, wherein the enzyme is arginase.
Claim 15
Dependent Claim
61 words
Method according to any of the preceding claims 1-13, further characterized in that the washing stage (b) is effected by circulating through the lumens of the fibres in the bundle at first deionized water to a total volume amounting to at least 10 times the total volume of the lumens of the fibres, and subsequently a dilute aqueous solution of glycerol.
Claim 16
Dependent Claim
20 words
Method according to claim 14, wherein the glycerol concentration in the said solution is from 8 to 15 vol. %.
Claim 17
Dependent Claim
13 words
1 6. Method according to claim 15., wherein said concentration is 10 vol.%.
Claim 18
Dependent Claim
41 words
Method according to any of the preceding claim 1-16, wherein the fibre bundle containing the immobilized enzyme is sterilized by exposing the fibres to an external sterilizing agent while the fibres are filled with a buffer solution specific to the enzyme.
Claim 19
Dependent Claim
24 words
Method according to claim 17, wherein the sterilization is effected by exposing the fibres to a gamma- radiation at a dosage of 2.5 Mrad.
Claim 20
Dependent Claim
26 words
1 9. Method according to claim 17, wherein the sterilization is effected by exposing the fibres to a gaseous mixture of ethylene oxide with a "Freon".
Claim 21
Dependent Claim
23 words
Method according to claim 19, wherein the gaseous mixture consists of 12 vol.% of ethylene oxide and 88 - vol.% of "Freon 12".
Claim 22
Dependent Claim
20 words
method according to claims 17 and 18, wherein the buffer solution additionally comprises glycerol as protective agent for the fibres.
Claim 23
Dependent Claim
30 words
Fibre-bundle dialyzer for haemodialysis comprising hollow cellulosic fibres containing an enzyme immobilized on the lumen surfaces of the fibres by a method according to any of the preceding claims 1-21.
References Cited (Backward Citations)
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