US5645587A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prevention of calcification and degeneration of biological tissue grafts for implantation in humans
Assignee: Individual
•
Filing: 1996-06-05
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Granted: 1997-07-08
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Expires: 2016-06-05
Abstract
Abstract The present invention relates to chemical treatment for prevention of calcification and degeneration of biological tissue grafts used as a whole or in a part as heart valve substitutes, substitutes of blood vessel, pericardial substitutes, and surgical membranes for implantation in human. The process includes the steps of treatment of the grafts with partially degraded heparin to prevent the calcification of glutaraldehyde-treated xenografts.
Inventors
- 👤 Jyotirmay Chanda
- 👤 Ryosei Kuribayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:25
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/36; A61L27/3683; A61L27/3687; A61L27/3604; A61L27/50; A61L2400/00; A61L2400/02; Y; Y10; Y10S; Y10S623/00; Y10S623/92; Y10S623/921
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
40 words
A calcification retardant bioprosthetic xenograft comprising removing tissue from a donor animal; cross-linking said tissue with glutaraldehyde; treating said cross-linked tissue with partially degraded heparin; and treating said cross-linked tissue with gentamicin, glycine and chitosan before treatment with degraded heparin.
Claim 2
Dependent Claim
40 words
A calcification retardant bioprosthetic xenograft comprising removing tissue from a donor animal; cross-linking said tissue with glutaraldehyde; treating said cross-linked tissue with partially degraded heparin; and treating said cross-linked tissue with gentamicin, glycine and chitosan before treatment with degraded heparin.
Claim 3
Dependent Claim
25 words
The xenograft as claimed in claim 1 wherein said cross linked tissue is treated with said partially degraded heparin for a period of one week.
Claim 4
Dependent Claim
34 words
The xenograft as claimed in claim 1 wherein said tissue is selected from the group consisting of heart valves, vessels, pericardium, dura mater, skin, amniotic membrane, umbilical cord, muscle tendons, ligaments, fascias and gut.
Claim 5
Independent Claim
54 words
A method for treating a xenograft tissue to prevent in vivo calcification and degeneration comprising; cross-linking tissue with glutaraldehyde; treating said cross-linked tissue with partially degraded heparin in normal saline; said cross-linked tissue is treated with a solution containing chitosan, glycine and gentamicin sulfate in normal saline solution before binding with partially degraded heparin.
Claim 6
Independent Claim
54 words
A method for treating a xenograft tissue to prevent in vivo calcification and degeneration comprising; cross-linking tissue with glutaraldehyde; treating said cross-linked tissue with partially degraded heparin in normal saline; said cross-linked tissue is treated with a solution containing chitosan, glycine and gentamicin sulfate in normal saline solution before binding with partially degraded heparin.
Claim 7
Dependent Claim
23 words
The method of claim 4 wherein a concentration of partially degraded heparin in the normal saline used for binding is 0.1 weight percent.
Claim 8
Dependent Claim
22 words
The method of claim 4 wherein said cross-linked tissue is treated with said partially degraded heparin for a period of one week.
Claim 9
Dependent Claim
22 words
The method of claim 6 wherein said cross-linked tissue is treated with said partially degraded heparin for three consecutive one week periods.
Claim 10
Dependent Claim
18 words
The method of claim 7 wherein said treated tissue is stored in normal saline containing glycine and gentamicin.
Claim 11
Dependent Claim
26 words
The method of claim 7 wherein after a final heparin binding said cross-linked tissue is washed first in chitosan then in chitosan-glycine-gentamicin sulfate in normal saline.
Claim 12
Dependent Claim
25 words
The method of claim 4 wherein said xenograft tissue is primarily cross-linked in glutaraldehyde in normal saline (pH 7.4) not more than 0.25 weight percent.
Claim 13
Dependent Claim
36 words
The method of claim 4 wherein said xenograft tissue is selected from the group consisting of heart valves, vessels, pericardium, dura mater, skin, amniotic membrane, umbilical cord, muscle tendons, ligaments, fascias and gut of mammalian origin.
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) | 2000-07-07 | 2001-01-06 | 2001-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-07 | 2005-01-06 | 2005-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-07 | 2009-01-06 | 2009-07-08 | $7700.00 | Window Closed / Lapsed |