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US4271070A
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Chemically-modified fiber collagen hemostatic agents
Assignee: Cornell Research Foundation Inc
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Filing: 1980-05-05
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Granted: 1981-06-02
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Expires: 2000-05-05
Abstract
Abstract Chemically-modified quaternary-structured fiber collagens of minimum molecular length, diameter and periodicity, and containing a relatively high positive electrostatic charge are claimed as hemostatic agents. Specific examples are guanidinated, esterified, and guanidinated-esterified collagen fibers of the type described.
Inventors
- 👤 Teruo Miyata
- 👤 Albert L. Rubin
- 👤 Kurt H. Stenzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:05
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/435; C07K14/78; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/32; A61L15/325; A61K; A61K38/00; A61L2400/00; A61L2400/04; Y; Y10; Y10S; Y10S128/00; Y10S128/08; Y10S530/00; Y10S530/827; Y10S530/84
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
74 words
An improved collagen hemostatic agent comprising native crosslinked fiber collagen of regularly staggered quaternary structure having a minimum molecular length of 7000 A°, a minimum molecular diameter of 20 A°, a minimum periodicity of 670-700 A°, and whose residual lysyl and carboxyl groups have been subjected respectively to at least one reaction selected from the group consisting of guanidination, esterification and guanidination-esterification to greatly enhance the net positive electrostatic charge of the fiber collagen.
Claim 2
Dependent Claim
74 words
An improved collagen hemostatic agent comprising native crosslinked fiber collagen of regularly staggered quaternary structure having a minimum molecular length of 7000 A°, a minimum molecular diameter of 20 A°, a minimum periodicity of 670-700 A°, and whose residual lysyl and carboxyl groups have been subjected respectively to at least one reaction selected from the group consisting of guanidination, esterification and guanidination-esterification to greatly enhance the net positive electrostatic charge of the fiber collagen.
Claim 3
Dependent Claim
15 words
A hemostatic agent of claim 1 in which the collagen is native animal tendon collagen.
Claim 4
Dependent Claim
16 words
A hemostatic agent of claim 1 in which the fiber collagen lysyl residues have been guanidinated.
Claim 5
Dependent Claim
16 words
A hemostatic agent of claim 1 in which the fiber collagen carboxyl residues have been esterified.
Claim 6
Dependent Claim
21 words
A hemostatic agent of claim 1 in which the fiber collagen lysyl and carboxyl residues have been guanidinated and esterified respectively.
Claim 7
Dependent Claim
16 words
A hemostatic agent of claim 1 in which the fiber collagen is in sponge sheet form.
Claim 8
Dependent Claim
15 words
A hemostatic agent of claim 1 in which the fiber collagen is in powder form.
Claim 9
Independent Claim
90 words
A method of preparing an improved fiber collagen hemostatic agent which comprises forming an acidic dispersion of native fiber collagen characterized by regularly staggered quaternary structure having a minimum molecular length of 7,000 A, a minimum molecular diameter of 20 A, and a minimum periodicity of 670-700 A, subjecting the dispersion to at least one chemical reaction selected from the group consisting of esterification, guanidination, and esterification-guanidination, whereby the net positive electrostatic charge of the fiber collagen is greatly enhanced, and recovering the chemically-modified fiber collagen from the reaction mixture.
Claim 10
Independent Claim
90 words
A method of preparing an improved fiber collagen hemostatic agent which comprises forming an acidic dispersion of native fiber collagen characterized by regularly staggered quaternary structure having a minimum molecular length of 7,000 A, a minimum molecular diameter of 20 A, and a minimum periodicity of 670-700 A, subjecting the dispersion to at least one chemical reaction selected from the group consisting of esterification, guanidination, and esterification-guanidination, whereby the net positive electrostatic charge of the fiber collagen is greatly enhanced, and recovering the chemically-modified fiber collagen from the reaction mixture.
Claim 11
Dependent Claim
17 words
A method according to claim 8 in which the fiber collagen dispersion is made from animal tendon.
Claim 12
Dependent Claim
26 words
A method according to claim 8 in which the acidic dispersion is dissolved in water and the solution brought to an alkaline pH before chemical reaction.
References Cited (Backward Citations)
US2973302A
Cited
US3071477A
Cited
US3034852A
Cited
US3157524A
Cited
US3114593A
Cited
US3314861A
Cited
US3393080A
Cited
US3649347A
Cited
US3637642A
Cited
US3632361A
Cited
US3898129A
Cited
US4140537A
Cited
US4066083A
Cited
US4215200A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-01 | 1984-12-01 | 1985-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-01 | 1988-12-01 | 1989-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-01 | 1992-12-01 | 1993-06-02 | $7700.00 | Window Closed / Lapsed |