US3616935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of antithrombogenic surfaces
Assignee: Dow Chemical Co
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Filing: 1970-02-05
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Granted: 1971-11-02
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Expires: 1990-02-05
Abstract
Abstract Antithrombogenicity may be obtained by irreversibly adsorbing polyalkylenimine on the surface of a variety of materials such as cellulose, glass, silicon rubber and the like and after thoroughly washing to remove any unadsorbed polymer heparinizing the surface by treating it with a solution of sodium heparin.
Inventors
- 👤 Jim Love
- 👤 George W Holmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:07
CPC Classifications
A; A61; A61L; A61L33/00; A61L33/0005; A61L33/0011; A61L33/0029; C; C08; C08J; C08J7/00; C08J7/04; C08J7/0427; C08J2479/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
16 words
The process of claim 2 wherein said cellulose is a permeable membrane useful for blood dialysis.
Claim 2
Dependent Claim
14 words
The process of claim 3 wherein said membrane is a permeable hollow, fine fiber.
Claim 3
Dependent Claim
10 words
The process of claim 1 wherein said polyalkylenimine is polyethylenimine.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said antithrombogenic material is heparin.
Claim 5
Dependent Claim
27 words
The process of claim 1 wherein said washing step (b) comprises a water wash following by a dilute acid wash which is followed by another water wash.
Claim 6
Dependent Claim
15 words
The process of claim 1 wherein said washing step (b) utilizes an isotonic sAline solution.
Claim 7
Dependent Claim
56 words
An article having at least one surface with antithrombogenic properties, said article surface comprising an anionic antithrombogenic material bound to a surface having polyalkylenimines having two to four carbon atoms per imine unit and an average molecular weight of at least about 50,000 irreversibly adsorbed thereon and wherein said surface is essentially free of unadsorbed polyalkylonimine.
Claim 8
Dependent Claim
116 words
A process for imparting antithrombogenic properties to materials having a surface capable of irreversibly adsorbing polyalkylenimines thereon, said process comprising. a. treating said surface with a 3 to 5 molar sodium chloride solution of an anionic antithrombogenic material and a polyalkylenimine having two to four carbon atoms per imine unit and an average molecular weight of at least about 50,000 wherein said solution has a pH of at least about 5; then b. diluting said solution while in contact with said surface whereby said antithrombogenic material bonds to said surface; and c. washing said surface essentially free of any unbound polyalkylenimine and antithrombogenic material. 10 The article of claim 9 wherein said antithrombogenic material is heparin.
References Cited (Backward Citations)
US3441142A
Cited
US3522346A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |