Patent US4544638A successfully refreshed from Google Patents.
US4544638A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of cross-links in the helical domain of collagen using pyridoxal 5-phosphate and copper or iron
Assignee: University of California
•
Filing: 1984-05-18
•
Granted: 1985-10-01
•
Expires: 2004-05-18
Abstract
Abstract Aldehyde cross-link intermediates and cross-links are generated in the central helical portion of collagen by incubating collagen with pyridoxal-5-phosphate and either cupric copper ion or ferrous iron ion. The cross-links are chemically similar to natural cross-links found in the non-helical regions and are directly between amino-acid moieties naturally occuring in the central helical portion of collagen. Cross-linking and utilization of aldehyde intermediates occurs when the product is reincubated after pyridoxal is removed. Alternatively maintaining the product at body temperatures will promote cross-linking. The cross-linked collagen product has increased resistance to enzyme degradation.
Inventors
- 👤 Robert C. Siegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:22
CPC Classifications
C; C09; C09H; C09H7/00; C08; C08H; C08H1/00; C08H1/06
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
43 words
An in vitro method for increasing the resistance to degradation of a proteolytic enzyme treated and purified collagen product comprising incubating said proteolytic enzyme treated collagen product with pyridoxal 5-phosphate and an ionic metal selected from the group consisting of copper and iron.
Claim 2
Dependent Claim
43 words
An in vitro method for increasing the resistance to degradation of a proteolytic enzyme treated and purified collagen product comprising incubating said proteolytic enzyme treated collagen product with pyridoxal 5-phosphate and an ionic metal selected from the group consisting of copper and iron.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein incubation is undertaken at a temperature between 25° C. and 37° C.
Claim 4
Independent Claim
16 words
The method of claims 1 wherein the incubation is undertaken at a pH of about 6-7.
Claim 5
Dependent Claim
10 words
The method of claim 3 wherein the pH is 6.4.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein incubation continues for a period of from 2 to 24 hours.
Claim 7
Dependent Claim
34 words
The method of claim 5 wherein the reaction materials are dialysed following incubation to remove the pyridoxal-5-phosphate and the ionic metal, the collagen is thereafter recovered, and incubated a second time to form cross-links.
Claim 8
Dependent Claim
37 words
An in vitro method for producing native cross-linking sites on a proteolytic enzyme treated and purified collagen product comprising incubating said collagen product with pyridoxal-5-phosphate and metal ion selected from the group consisting of copper and iron.
Claim 9
Dependent Claim
37 words
An in vitro method for producing native cross-linking sites on a proteolytic enzyme treated and purified collagen product comprising incubating said collagen product with pyridoxal-5-phosphate and metal ion selected from the group consisting of copper and iron.
Claim 10
Dependent Claim
15 words
The method of claim 7 wherein the ionic copper is in the +2 oxidation state.
Claim 11
Dependent Claim
15 words
The method of claim 7 wherein the ionic iron is in the +2 oxidation state.
Claim 12
Dependent Claim
59 words
An in vitro method for producing cross-links in a proteolytic enzyme treated and purified collagen product comprising incubating said collagen product with pyridoxal-5-phosphate and an ionic metal selected from the group consisting of copper and iron, thereafter removing the pyridoxal-5-phosphate and ionic metal from the incubated collagen product, and then reincubating the collagen product alone until cross-links are formed.
Claim 13
Dependent Claim
59 words
An in vitro method for producing cross-links in a proteolytic enzyme treated and purified collagen product comprising incubating said collagen product with pyridoxal-5-phosphate and an ionic metal selected from the group consisting of copper and iron, thereafter removing the pyridoxal-5-phosphate and ionic metal from the incubated collagen product, and then reincubating the collagen product alone until cross-links are formed.
Claim 14
Dependent Claim
17 words
The method of claim 10 wherein the Pyridoxal-5-phosphate is present in a concentration of about 0.001 molar.
Claim 15
Dependent Claim
18 words
The method of claim 10 wherein the ionic metal is present in a concentration of about 0.002 molar.
Claim 16
Dependent Claim
27 words
The method of claim 10 wherein the incubations are carried at a temperature of between 25° C. and 37° C., and at a pH of about 6-7.
Claim 17
Dependent Claim
65 words
An in vitro method for producing cross-linking sites in a product consisting essentially of the central helical portions of collagen comprising incubating said collagen product with pyrodoxal-5-phosphate and metal ion selected from the group consisting of cupric copper and ferrous iron, and continuing the incubation until at least some of the lysyl and hydroxylysyl moieties in the collagen are converted into the aldehyde functional form.
Claim 18
Dependent Claim
65 words
An in vitro method for producing cross-linking sites in a product consisting essentially of the central helical portions of collagen comprising incubating said collagen product with pyrodoxal-5-phosphate and metal ion selected from the group consisting of cupric copper and ferrous iron, and continuing the incubation until at least some of the lysyl and hydroxylysyl moieties in the collagen are converted into the aldehyde functional form.
Claim 19
Dependent Claim
27 words
The method of claim 14, wherein the incubation is carried out at a temperature between 25°0 C. and 37° C., and at a pH of about 6-7.
Claim 20
Dependent Claim
29 words
The method of claim 14 wherein the metal ion is present in a concentration of about 0.002 and the pyridoxal-5-phosphate is present in a concentration of about 0.002 M.
Claim 21
Dependent Claim
41 words
A collagen product consisting essentially of the central helical portion of native collagen and having cross-links of the native type produced by incubating reaction mixture consisting essentially of said collagen with pyridoxal-5-phosphate and either cupric copper ion or ferrous iron ion.
Claim 22
Dependent Claim
41 words
A collagen product consisting essentially of the central helical portion of native collagen and having cross-links of the native type produced by incubating reaction mixture consisting essentially of said collagen with pyridoxal-5-phosphate and either cupric copper ion or ferrous iron ion.
Claim 23
Dependent Claim
38 words
A collagen product consisting essentially of the central helical portion of native collagen and having cross-linking sites produced by incubating reaction mixture consisting essentially of said collagen with pyridoxal-5-phosphate and either cupric copper ion or ferrous iron ion.
Claim 24
Dependent Claim
38 words
A collagen product consisting essentially of the central helical portion of native collagen and having cross-linking sites produced by incubating reaction mixture consisting essentially of said collagen with pyridoxal-5-phosphate and either cupric copper ion or ferrous iron ion.
References Cited (Backward Citations)
US3131130A
Cited
US3530037A
Cited
US4233360A
Cited
US4193813A
Cited
US4260228A
Cited
US4271070A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |