Patent US4396716A successfully refreshed from Google Patents.
US4396716A
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Preparation of biocompatible materials by immobilization of apyrase
Assignee: Eni SpA
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Filing: 1981-12-28
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Granted: 1983-08-02
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Expires: 2001-12-28
Abstract
Abstract A prosthetic polymer material is made non-thrombogenic by immobilizing apyrase on its surface. Immobilization is preferably carried out by hydrolytically activating the surface of a polyamide polymer or a polyethylene terphthalate polymer, and treating the hydrolyzed polymer with a solution of cross-linking agent and a solution of apyrase. The apyrase converts adenosine diphosphate to adenosine monophosphate and adenosine whereby the formation of thrombi is inhibited.
Inventors
- 👤 Walter Marconi
- 👤 Francesco Bartoli
- 👤 Francesco Pittalis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:23
CPC Classifications
C; C12; C12N; C12N11/00; A; A61; A61L; A61L33/00; A61L33/0005; A61L33/0047
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A method for preparing a non-thrombogenic apyrase-carrying prosthetic plastic material comprising the steps of hydrolytically activating the surface of a plastic material carrier selected from the group consisting of a polyamide polymer and a polyethylene terephthalate polymer, treating the hydrolyzed plastic carrier by immersing it into a buffered solution of a cross-linking agent selected from the group consisting of glutaraldehyde and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide and in a buffered solution of apyrase, and allowing said immersed plastic material carrier to stand for a time sufficient to effect the covalent bonding of apyrase to the surface of said plastic material carrier.
Claim 2
Independent Claim
97 words
A method for preparing a non-thrombogenic apyrase-carrying prosthetic plastic material comprising the steps of hydrolytically activating the surface of a plastic material carrier selected from the group consisting of a polyamide polymer and a polyethylene terephthalate polymer, treating the hydrolyzed plastic carrier by immersing it into a buffered solution of a cross-linking agent selected from the group consisting of glutaraldehyde and N-ethyl-N'-(3-dimethylaminopropyl)carbodiimide and in a buffered solution of apyrase, and allowing said immersed plastic material carrier to stand for a time sufficient to effect the covalent bonding of apyrase to the surface of said plastic material carrier.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said plastic material carrier is a polyamide and said hydrolysis is an acid hydrolysis.
Claim 4
Dependent Claim
53 words
The method of claim 1 wherein said plastic material carrier is polyethylene terephthalate, said hydrolysis is an alkaline hydrolysis, and said solution of a cross-linking agent is a buffered solution of N-ethyl-N'-(dimethylaminopropyl)carbodiimide, which solution is combined with said buffered solution of apyrase prior to the immersion therein of said hydrolytically-activated plastic material carrier.
Claim 5
Dependent Claim
37 words
Non-thrombogenic apyrase-carrying prosthetic plastic material articles prepared by the method of claim 1 consisting of plastic material from the group consisting of polyamides and polyethylene terephthalate having said apyrase covalently and permanently bonded on the surface thereof.
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) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |