US5290494A
Expired / Lapsed
US
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Process of making a resorbable implantation device
Assignee: The University of Texas System
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Filing: 1992-07-16
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Granted: 1994-03-01
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Expires: 2012-07-16
Abstract
Abstract Resorbable materials and their preparation based on gelling a solution of a single polylactide enantiomer. The gel may be dried to produce solid materials, or may be extracted with a nonsolvent prior to drying to make microporous materials. Physical and mechanical properties of the material may be varied by varying the molecular weight of the gelling polymer, or by blending the gelling solution with other polymers or fillers. The resorbable materials can be used to make biodegradable implantation devices.
Inventors
- 👤 Allan G. A. Coombes
- 👤 James D. Heckman
- 👤 Barbara D. Boyan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:52
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/28; A61L; A61L27/00; A61L27/14; A61L27/18; A61L27/50; A61L27/58; C; C08; C08J; C08J9/00; C08J9/28; A61F2/30; A61F2/3094; A61F2002/2835; A61F2002/30001; A61F2002/30003; A61F2002/30004; A61F2002/3006; A61F2002/30062; A61F2002/30065; A61F2002/30108; A61F2002/3011; A61F2002/30112; A61F2002/30113; A61F2002/30199; A61F2002/302; A61F2002/30224; A61F2002/30225; A61F2002/30667; A61F2002/30677; A61F2/30767; A61F2/30771; A61F2002/30772; A61F2002/30784; A61F2002/30785; A61F2210/00; A61F2210/0004; A61F2210/0071; A61F2230/00; A61F2230/0002; A61F2230/0004; A61F2230/0006; A61F2230/0063; A61F2230/0065; A61F2230/0069; A61F2250/00; A61F2250/0014; C08J2367/00; C08J2367/04; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
68 words
A method for making a resorbable implantation device, comprising the steps of: dissolving an independently-gelling single polylactide enantiomer in a solvent to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; and drying the gel to form a resorbable implantation device.
Claim 2
Independent Claim
68 words
A method for making a resorbable implantation device, comprising the steps of: dissolving an independently-gelling single polylactide enantiomer in a solvent to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; and drying the gel to form a resorbable implantation device.
Claim 3
Independent Claim
86 words
A method for making a resorbable implantation deice, comprising the steps of: dissolving an independently-gelling single polylactide enantiomer in a solvent to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; extracting the solvent with a nonsolvent such that the polymer precipitates to form a substantially microporous material; and drying the microporous material to form a resorbable implantation device.
Claim 4
Independent Claim
86 words
A method for making a resorbable implantation deice, comprising the steps of: dissolving an independently-gelling single polylactide enantiomer in a solvent to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; extracting the solvent with a nonsolvent such that the polymer precipitates to form a substantially microporous material; and drying the microporous material to form a resorbable implantation device.
Claim 5
Dependent Claim
10 words
The method of claim 2, wherein the nonsolvent is organic.
Claim 6
Dependent Claim
31 words
The method of claim 3, further comprising the step of, after the extracting step and before the drying step, immersing the microporous material in water to extract the organic nonsolvent molecules.
Claim 7
Dependent Claim
10 words
The method of claim 2, wherein the nonsolvent is water.
Claim 8
Dependent Claim
15 words
The method of claim 1 or 2, wherein the solvent is acetone or ethyl acetate.
Claim 9
Dependent Claim
29 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is dissolved in the solvent to a concentration of from about 1 to about 10% weight/volume.
Claim 10
Dependent Claim
29 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is dissolved in the solvent to a concentration of from about 2.5 to about 10% weight/volume.
Claim 11
Dependent Claim
29 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is dissolved in the solvent to a concentration of from about 7 to about 9% weight/volume.
Claim 12
Dependent Claim
17 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is based on L-lactide.
Claim 13
Dependent Claim
16 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is poly L-lactide).
Claim 14
Dependent Claim
17 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is based on D-lactide.
Claim 15
Dependent Claim
15 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is poly(D-lactide).
Claim 16
Dependent Claim
22 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer is a copolymer of lactide and another alpha-hydroxy acid.
Claim 17
Dependent Claim
13 words
The method of claim 14, wherein the other alpha-hydroxy acid comprises glycolic acid.
Claim 18
Dependent Claim
25 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer has a weight average molecular weight of between about 50,000 and 200,000.
Claim 19
Dependent Claim
22 words
The method of claim 1 or 2, wherein the independently-gelling single polylactide enantiomer has a weight average molecular weight of around 100,000.
Claim 20
Dependent Claim
21 words
The method of claim 1 or 2, wherein a second material is dissolved in the solvent before the gel forming step.
Claim 21
Dependent Claim
23 words
The method of claim 18, wherein the ratio of the independently-gelling single polylactide enantiomer to the second material is at least about 1:9.
Claim 22
Dependent Claim
12 words
The method of claim 18, wherein the second material comprises a polymer.
Claim 23
Dependent Claim
38 words
The method of claim 20, wherein the second polymer comprises a polymer of an alpha-hydroxy acid, a polymer of a lactone, a copolymer at least one alpha-hydroxy acid, a polyethylene oxide, or a copolymer containing a thermoplastic elastomer.
Claim 24
Dependent Claim
21 words
The method of claim 1 or 2, wherein a filler material is added to the solvent before the gel forming step.
Claim 25
Dependent Claim
21 words
The method of claim 1 or 2, wherein the molded gel has a minimum thickness of at least about 2 mm.
Claim 26
Dependent Claim
21 words
The method of claim 1 or 2, wherein the molded gel has a minimum thickness of at least about 5 mm.
Claim 27
Dependent Claim
21 words
The method of claim 1 or 2, wherein the molded gel has a minimum thickness of at least about 10 mm.
Claim 28
Dependent Claim
32 words
The method of claim 1, wherein the drying step comprises: partially drying the gel; extracting the solvent molecules with water to form a microporous material; and drying the water extracted microporous material.
Claim 29
Dependent Claim
28 words
The method of claim 2, wherein the drying step comprises: partially drying the microporous material; extracting the nonsolvent molecules with water; and drying the water extracted microporous material.
Claim 30
Independent Claim
93 words
A method for making a resorbable implantation device, comprising the steps of: heating an independently-gelling single polylactide enantiomer, having a weight average molecular weight of between about 50,000 and 200,000, in acetone or ethyl acetate, such that said enantiomer dissolves in the acetone or ethyl acetate to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; and drying the gel to form a resorbable implantation device.
Claim 31
Independent Claim
93 words
A method for making a resorbable implantation device, comprising the steps of: heating an independently-gelling single polylactide enantiomer, having a weight average molecular weight of between about 50,000 and 200,000, in acetone or ethyl acetate, such that said enantiomer dissolves in the acetone or ethyl acetate to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; and drying the gel to form a resorbable implantation device.
Claim 32
Independent Claim
114 words
A method for making a resorbable implantation device, comprising the steps of: heating an independently-gelling single polylactide enantiomer, having a weight average molecular weight of between about 50,000 and 200,000, in acetone or ethyl acetate, such that said enantiomer dissolves in the acetone or ethyl acetate to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; extracting the acetone or ethyl acetate with a nonsolvent such that the polymer precipitates to form a substantially microporous material; and drying the microporous material to form a resorbable implantation device.
Claim 33
Independent Claim
114 words
A method for making a resorbable implantation device, comprising the steps of: heating an independently-gelling single polylactide enantiomer, having a weight average molecular weight of between about 50,000 and 200,000, in acetone or ethyl acetate, such that said enantiomer dissolves in the acetone or ethyl acetate to form a polymer solution; casting the polymer solution in a mold; allowing the polymer solution to cool to form a gel capable of substantially retaining the shape of the mold upon removal therefrom and handling thereof; extracting the acetone or ethyl acetate with a nonsolvent such that the polymer precipitates to form a substantially microporous material; and drying the microporous material to form a resorbable implantation device.
Claim 34
Dependent Claim
20 words
The method of claim 1 or 28, further comprising the step of forming at least one bore in the gel.
Claim 35
Dependent Claim
21 words
The method of claim 2 or 29, further comprising the step of forming at least one bore in the microporous material.
Claim 36
Dependent Claim
23 words
The method of claim 1, 2, 28, or 29, further comprising the step of incorporating a bioactive material into the resorbable implantation device.
References Cited (Backward Citations)
US4471077A
Cited
US4550449A
Cited
US4563489A
Cited
US4578384A
Cited
US4637931A
Cited
US4645503A
Cited
US4776329A
Cited
US4792336A
Cited
US4781183A
Cited
US4719246A
Cited
US4800219A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-02-28 | 1997-08-30 | 1998-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-28 | 2001-08-30 | 2002-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-28 | 2005-08-30 | 2006-03-01 | $7700.00 | Window Closed / Lapsed |