US5869080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Absorbable implant materials having controlled porosity
Assignee: Systagenix Wound Management IP Co BV
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Filing: 1996-05-28
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Granted: 1999-02-09
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Expires: 2016-05-28
Abstract
Abstract Absorbable implant materials having controlled porosity are formed by a method comprising the steps of: providing a dispersion of a bioabsorbable polymer, such as collagen, in a first solvent, such as water; adding particles of a second material, e.g. frozen water droplets or ice particles to the dispersion; followed by freezing the dispersion to form a frozen dispersion having the particles embedded therein, and removing both the first solvent and the second material from the frozen dispersion by freeze-drying or solvent extraction to leave the porous implant material. The invention also encompasses the use of such implant materials for wound healing applications.
Inventors
- 👤 James McGregor
- 👤 Paul W. Watt
- 👤 Nicholas D. Light
- 👤 Wilson Harvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:31
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/58; A61L15/00; A61L15/16; A61L15/42; A61L15/425; A61L15/64; A61L27/56
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
107 words
A method of making a bioabsorbable material having interconnecting pores comprising the steps of: providing a dispersion of a bioabsorbable polymer in a first solvent capable of dissolving or suspending said bioabsorbable polymer; adding particles of a second material, which is capable of being removed from said dispersion by freeze drying or solvent drying, to the dispersion; followed by freezing the dispersion to form a frozen dispersion having the particles embedded therein, and removing said first solvent and the particles of the second material from said frozen dispersion in a single step by freeze drying or solvent drying, the removal of the particles thereby forming the pores.
Claim 2
Independent Claim
107 words
A method of making a bioabsorbable material having interconnecting pores comprising the steps of: providing a dispersion of a bioabsorbable polymer in a first solvent capable of dissolving or suspending said bioabsorbable polymer; adding particles of a second material, which is capable of being removed from said dispersion by freeze drying or solvent drying, to the dispersion; followed by freezing the dispersion to form a frozen dispersion having the particles embedded therein, and removing said first solvent and the particles of the second material from said frozen dispersion in a single step by freeze drying or solvent drying, the removal of the particles thereby forming the pores.
Claim 3
Dependent Claim
52 words
A method according to claim 1, wherein the particles of the second material are frozen droplets or frozen particles of a second solvent, which is capable of being frozen, and said adding step is carried out while the dispersion is maintained at a temperature below the melting point of the second solvent.
Claim 4
Dependent Claim
16 words
A method according to claim 2, wherein the first and second solvents comprise the same liquid.
Claim 5
Dependent Claim
23 words
A method according to claim 1, wherein the said particles are droplets of a second solvent which is immiscible in the first solvent.
Claim 6
Dependent Claim
22 words
A method according to claim 1, wherein the step of removing comprises removing the first solvent and second material by freeze drying.
Claim 7
Dependent Claim
23 words
A method according to claim 1, wherein the steps of removing comprises removing the first solvent and the second material by solvent drying.
Claim 8
Dependent Claim
12 words
A method according to claim 1, wherein the first solvent comprises water.
Claim 9
Dependent Claim
15 words
A method according to claim 1, wherein the bioabsorbable polymer comprises one or more biopolymers.
Claim 10
Dependent Claim
21 words
A method according to claim 8, wherein the biopolymers are selected from the group consisting of collagen, fibrin, laminin and fibronectin.
Claim 11
Dependent Claim
14 words
A method according to claim 8, wherein the bioabsorbable polymer consists essentially of collagen.
Claim 12
Dependent Claim
20 words
A method according to claim 1, further comprising the step of treating the bioabsorbable polymer with a chemical cross-linking agent.
Claim 13
Dependent Claim
22 words
A method according to claim 1 wherein at least some of said particles have a minimum dimension in the range 0.1-3.0 mm.
Claim 14
Dependent Claim
22 words
A method according to claim 12, wherein at least some of said particles have a minimum dimension in the range 0.3-1.0 mm.
Claim 15
Dependent Claim
24 words
A method according to claim 1, wherein the weight ratio of said particles to said dispersion of bioabsorbable polymer is from 1:1 to 20:1.
Claim 16
Dependent Claim
13 words
A porous bioabsorbable implant material obtainable by a process according to claim 1.
Claim 17
Dependent Claim
18 words
An implant or dressing for the treatment of wounds comprising a porous bioabsorbable material according to claim 15.
Claim 18
Dependent Claim
19 words
A method of treating a wound comprising applying thereto or thereinto a porous bioabsorbable material according to claim 15.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |