US6160084A
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US
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Biodegradable shape memory polymers
Assignee: Massachusetts Institute of Technology
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Filing: 1999-02-23
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Granted: 2000-12-12
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Expires: 2019-02-23
Abstract
Abstract Biodegradable shape memory polymer compositions, articles of manufacture thereof, and methods of preparation and use thereof are described. In one embodiment the compositions include at least one hard segment and at least one soft segment. The Ttrans of the hard segment is preferably between -30 and 270 DEG C. At least one of the hard or soft segments can contain a crosslinkable group, and the segments can be linked by formation of an interpenetrating network or a semi-interpenetrating network, or by physical interactions of the segments. Objects can be formed into a given shape at a temperature above the Ttrans of the hard segment, and cooled to a temperature below the Ttrans of the soft segment. If the object is subsequently formed into a second shape, the object can return to its original shape by heating the object above the Ttrans of the soft segment and below the Ttrans of the hard segment.
Inventors
- 👤 Robert S. Langer
- 👤 Andreas Lendlein
- 👤 Annette Schmidt
- 👤 Hans Grablowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:45
CPC Classifications
A; A61; A61L; A61L27/00; A61L31/00; A61L31/14; A61L31/148; A61L27/14; A61L27/18; A61L27/50; A61L27/58; A61L29/00; A61L29/14; A61L29/148; A61B; A61B17/00; A61B2017/00831; A61B2017/00867; A61B2017/00871; A61L2400/00; A61L2400/16
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
58 words
A degradable shape memory polymer composition having at least one shape in memory, the polymer comprising (1) hard and soft segments or (2) at least one soft segment, which is crosslinked covalently or ionically, or (3) polymer blends, wherein the original shape of the polymer is recovered by a change in temperature or by application of another stimulus.
Claim 2
Dependent Claim
58 words
A degradable shape memory polymer composition having at least one shape in memory, the polymer comprising (1) hard and soft segments or (2) at least one soft segment, which is crosslinked covalently or ionically, or (3) polymer blends, wherein the original shape of the polymer is recovered by a change in temperature or by application of another stimulus.
Claim 3
Dependent Claim
89 words
The composition of claim 1 comprising: a) at least one hard segment which has a T trans between -40 and 270° C., b) at least one soft segment which has a T trans at least 10° C. lower than that of the hard segment(s), which is linked to at least one hard segment, wherein at least one of the hard or soft segments includes a degradable region or at least one of the hard segment(s) is linked to at least one of the soft segment(s) through a degradable linkage.
Claim 4
Dependent Claim
23 words
The composition of claim 2 wherein the T trans of the hard segment is in the range of between 30 and 150° C.
Claim 5
Dependent Claim
23 words
The composition of claim 3 wherein the T trans of the hard segment is in the range of between 30 and 100° C.
Claim 6
Dependent Claim
24 words
The composition of claim 2 wherein the T trans of the soft segment(s) is at least 20° C. below that of the hard segment(s).
Claim 7
Dependent Claim
19 words
The composition of claim 2 wherein at least one of the hard and soft segments is a thermoplastic polymer.
Claim 8
Dependent Claim
12 words
The composition of claim 2 wherein the hard segment comprises cyclic moieties.
Claim 9
Dependent Claim
22 words
The composition of claim 2 wherein the ratio by weight of the hard and soft segments is between about 5:95 and 95:5.
Claim 10
Dependent Claim
24 words
The composition of claim 1 wherein the shape memory polymer is selected from the group consisting of graft polymers, linear polymers, and dendrimer polymers.
Claim 11
Dependent Claim
32 words
The composition of claim 1 wherein polymer comprises a biodegradable region selected from the group consisting of polyhydroxy acids, poly(ether ester)s, polyorthoesters, poly(amino acids), synthetic poly(amino acids), polyanhydrides, polycarbonates, poly(hydroxyalkanoate)s, and poly(ε-caprolactone)s.
Claim 12
Dependent Claim
29 words
The composition of claim 1 wherein the polymer comprises a biodegradable linkage selected from the group consisting of ester groups, carbonate groups, amide groups, anhydride groups, and orthoester groups.
Claim 13
Dependent Claim
11 words
The composition of claim 1 wherein the polymer is completely degradable.
Claim 14
Dependent Claim
43 words
The composition of claim 1 comprising: a degradable thermoset polymer that comprises a covalently crosslinked crystallizable soft segment having a T m between 250° C. and -40° C. or a covalently crosslinked soft segment having a T trans 250° C. and -60° C.
Claim 15
Dependent Claim
27 words
The composition of claim 13 wherein the degradable thermoset polymer comprises a covalently crosslinked crystallizable soft segment having a T m between 200° C. and 0° C.
Claim 16
Dependent Claim
101 words
The composition of claim 1 comprising a) at least one first segment which has a T trans between -40 and 270° C., b) at least one second segment which is linked to at least one first segment, and which comprises ionic interactions of sufficient strength that the second segment is able to form a physical crosslink other than a melting point or a glass transition, wherein at least one of the first or second segments includes a degradable region or at least one of the first segments is linked to at least one of the second segments through a degradable linkage.
Claim 17
Dependent Claim
21 words
The composition of claim 15 wherein the ionic interaction comprises polyelectrolyte segments or supramolecular effects based on highly organized hydrogen bonds.
Claim 18
Dependent Claim
26 words
The composition of claim 1 wherein the polymer has an inverse temperature effect, wherein the composition recovers its shape when cooled below its shape recovery temperature.
Claim 19
Dependent Claim
14 words
The composition of claim 1 wherein the polymer changes shape in response to light.
Claim 20
Dependent Claim
12 words
The composition of claim 1 wherein the polymer is a polymer blend.
Claim 21
Dependent Claim
16 words
The composition of claim 1 comprising a coating altering the degradation of the shape memory polymer.
Claim 22
Dependent Claim
16 words
An article comprising the biodegradable shape memory polymer composition of any of claims 1-20 or 26.
Claim 23
Dependent Claim
19 words
The article of claim 21 incorporating an agent selected from the group consisting of therapeutic, diagnostic and prophylactic agents.
Claim 24
Dependent Claim
18 words
The article of claim 21 wherein the article is implantable and the biodegradable shape memory polymer is biocompatible.
Claim 25
Dependent Claim
15 words
The article of claim 23 wherein the shape memory polymer does not contain aromatic groups.
Claim 26
Dependent Claim
27 words
The article of claim 21 wherein the article is a medical device selected from the group consisting of stents, catheters, prosthetics, grafts, screws, pins, pumps, and meshes.
Claim 27
Dependent Claim
79 words
The composition of claim 19 wherein the polymer blend is selected from the group consisting of physical mixtures of polymer, blends of polymers comprising hard segments with different Ttrans and soft segments having the same Ttrans, blends of multiblock copolymers wherein at least one of the segments of a first copolymer is miscible with at least one of the segments of a second copolymer, and blends of at least one multiblock copolymer and at least one homo or copolymer.
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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) | 2003-12-12 | 2004-06-12 | 2004-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-12-12 | 2008-06-12 | 2008-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-12-12 | 2012-06-12 | 2012-12-12 | $7700.00 | Window Closed / Lapsed |