EP0909301A1 - Biodegradable liquid crystalline polymers - Google Patents

Biodegradable liquid crystalline polymers

Info

Publication number
EP0909301A1
EP0909301A1 EP97926102A EP97926102A EP0909301A1 EP 0909301 A1 EP0909301 A1 EP 0909301A1 EP 97926102 A EP97926102 A EP 97926102A EP 97926102 A EP97926102 A EP 97926102A EP 0909301 A1 EP0909301 A1 EP 0909301A1
Authority
EP
European Patent Office
Prior art keywords
polymer
aromatic
moiety
bis
mesogenic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP97926102A
Other languages
German (de)
French (fr)
Inventor
Saad Aboul Majeed Ali
John Rose
Richard John Searle
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Smith and Nephew PLC
Original Assignee
Smith and Nephew PLC
Smith and Nephew Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Smith and Nephew PLC, Smith and Nephew Inc filed Critical Smith and Nephew PLC
Publication of EP0909301A1 publication Critical patent/EP0909301A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G67/00—Macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing oxygen or oxygen and carbon, not provided for in groups C08G2/00 - C08G65/00
    • C08G67/04—Polyanhydrides
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L24/00—Surgical adhesives or cements; Adhesives for colostomy devices
    • A61L24/04—Surgical adhesives or cements; Adhesives for colostomy devices containing macromolecular materials
    • A61L24/046—Surgical adhesives or cements; Adhesives for colostomy devices containing macromolecular materials obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
    • A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
    • A61L27/14—Macromolecular materials
    • A61L27/18—Macromolecular materials obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
    • C08G63/60—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
    • C08G63/60—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds
    • C08G63/605—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds the hydroxy and carboxylic groups being bound to aromatic rings

Definitions

  • This invention relates to novel polymers and particularly high performance bioresorbable polymers which have liquid crystalline properties.
  • Thermotropic polyesters are known and such materials generally possess advantageous properties such as, inter alia, high thermostability, low sensitivity to oxidation. However, such polyesters are generally not biodegradable.
  • biodegradable polymers such as those comprising lactic acid or ⁇ -hydroxybutyric, they are generally aliphatic in nature. Whilst they find utility in, for example, drug delivery systems or medical sutures, they do not possess the high strength and high modulus required for use in, eg. load bearing implants.
  • Polyester anhydrides are known from European Patent application No.0055527. However, the polyester anhydrides disclosed therein are not sufficiently bioresorbable or do not possess sufficient strength and/or modulus to be suitable as load bearing bioresorbable implants.
  • the polymeric material comprises repeating units of an aromatic mesogenic moiety, a hydroiysabie moiety and a spacer moiety.
  • the polymeric material is preferably a condensation product containing aromatic ester moieties as the mesogenic component, mixed aromatic and aliphatic anhydride moieties as the hydrolysable component and aliphatic chains as the spacer moiety.
  • these components may be provided by a condensation product comprising both aromatic and aliphatic diacid residues or functional derivatives thereof and residues of polyfunctional nucleophilic species such as a diol or thiol.
  • the preferred polymeric materials of the present invention are poly(ester-anhydride)s.
  • the mesogenic component may be derived from aromatic amide moieties.
  • the aromatic mesogenic moiety may be a polyester moiety and is preferably a condensation product of, for example, a terephthaloyl or isophthaloyl moiety and a quinoid such as hydroquinone, methylhydroquinone, phenyihydroquinone, biphenol or dihydroxynaphthalene or derivatives thereof.
  • aromatic mesogenic moiety aptly comprises a moiety of formula I.
  • a preferred mesogenic moiety comprises a moiety of the general formula II
  • the hydrolysable moiety may comprise any conventionally known hydrolysable group.
  • a preferred hydrolysable moiety is an anhydride linkage.
  • Such anhydrides may be the condensation product of an aliphatic diacid derivative and an aromatic diacid derivative, such as a terephthaloyi acid derivative, eg. terephthaloyi chloride or an isophthaloyl derivative such as isophthaloyl chloride.
  • the spacer moiety is any inert group and may preferably comprise an aliphatic chain, for example comprising methylene groups from C 2 to C 20 . suitably from C 2 to C 18 , and preferably from C 4 toC 10 .
  • the spacer moiety may comprise alkylene oxide units ethylene oxide, propylene oxide or tetramethyiene oxide units.
  • n is an integer from 2 to 20, preferably from 2 to 16, more preferably 4 to 10, R, and R 2 are as defined above and the ratio of x:y is from 1 :99 to 99:1
  • R, andR 2 is methyl-substitued phenyl.
  • a method of manufacturing a polymeric material as hereinbefore described which comprises condensing a terephthaloyi or isophthaloyl compound and a quinoid such as hydroquinone, methylhydroquinone, phenylhydroquinone, biphenol or dihydroxynaphthalene or derivatives thereof and an aliphatic diacid or derivative thereof.
  • the terephthaloyi or isophthaloyl derivative is preferably an acid haiide, eg. acid chloride such as terephthaloyi or isophthaloyl chloride. Such materials are generally commercially available.
  • the quinoid derivative is preferably an activated hydroquinone such as the silylated derivative, eg. bis-trimethylsilyl hydroquinone.
  • Bis-trialkylsilyl hydroquinones may be manufactured by, inter alia, reacting the respective quinoid with hexalkyldisiiazane.
  • the aliphatic diacid derivative is preferably an activated diacid such as a silylated diacid, eg. comprising silyl groups as hereinbefore described.
  • the polymeric material of the invention is advantageous in that it may be degradable to fragments of low molecular weight, which may in itself facilitate bioresorbability.
  • Such polymeric materials may be processed to produce high strength and high modulus materials which are useful in the manufacture of, inter alia, implantable devices, eg. implantable fixation devices such as bone fixation or prosthetic devices.
  • implantable devices eg. implantable fixation devices such as bone fixation or prosthetic devices.
  • the desired strength and modulus of the polymeric materials of the invention is evidenced by the presence of liquid crystal properties.
  • a medical fixation device comprising a polymeric material as hereinbefore described.
  • fixation devices are preformed to the shape of implantable prosthetic devices, such as femoral head or condylar prostheses or as a filling material, which may be suitably shaped, to replace missing or excised bone portions.
  • implantable prosthetic devices such as femoral head or condylar prostheses or as a filling material, which may be suitably shaped, to replace missing or excised bone portions.
  • Adipic acid (36.54g) and hexamethyldisilazane (48.42g) were refluxed in toluene (400ml) for 4 hours.
  • the resultant bis- trimethylsilyl adipate (84g) was isolated by vacuum distillation.
  • Terephthaloyi chloride (4.06g), bis-trimethylsilyl methyl- hydroquinone (4.3g), bis-trimethylsilyl dodecanedioate (1.5g) and benzyltriethylammonium chloride (0.01g) were weighed under nitrogen into a glass reaction vessel.
  • the reaction mixture was heated, with stirring under nitrogen, from 90 ' C to 260 * C over a period of 3 hours after which a vacuum was applied for a further half-hour.
  • the product was washed with dry tetrahydrofuran, dried under vacuum at 60 'C and characterised by FTIR spectral analysis, 13C-NMR spectral analysis and optical scanning under polarised light.
  • Figures 1 and 2 respectively, illustrate the FTIR and NMR spectra of the polymer.
  • Figure 3 is a monochromatic reproduction of a coloured microphotograph of the polymer demonstrating the liquid crystalline properties of the polymer. The micrograph was taken between cross polars whilst the polymer was molten.
  • the coloured region (textured region X shown in Figure 3) is evidence of a birefringent fluid which can only arise if there is molecular order in the liquid, i.e. a liquid crystalline polymer.
  • thread-like structures (Y) which are typically associated with nematic type liquid crystals. Examples 2 to 5
  • Poly(ester-anhydride)s having the compositions shown in the following table were prepared in accordance with the method described in Example 1. Each polymer exhibited thermotropic behaviour (viz. a liquid crystalline phase in the polymer melt).
  • Example 1 The method of Example 1 was used to prepare a polyester- anhydride) comprised of residues derived from 50 mole% terephthaloyi chloride, 37.5 mole% bis-trimethylsilyl hydroquinone and 12.5 mole% bis-trimethylsilyl dodecanedioate.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Epidemiology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Transplantation (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Dermatology (AREA)
  • Surgery (AREA)
  • Polyesters Or Polycarbonates (AREA)

Abstract

Novel thermotropic polymers, typically aromatic poly(ester-anhydride)s, having high modulus and biodegradability, have use as bone fixative materials and may be used in the construction of prosthetic devices and for filling other bone defects.

Description

BIODEGRADABLE LIQUID CRYSTALLINE POLYMERS
This invention relates to novel polymers and particularly high performance bioresorbable polymers which have liquid crystalline properties.
Thermotropic polyesters are known and such materials generally possess advantageous properties such as, inter alia, high thermostability, low sensitivity to oxidation. However, such polyesters are generally not biodegradable.
Although many biodegradable polymers are known, such as those comprising lactic acid or β-hydroxybutyric, they are generally aliphatic in nature. Whilst they find utility in, for example, drug delivery systems or medical sutures, they do not possess the high strength and high modulus required for use in, eg. load bearing implants.
Polyester anhydrides are known from European Patent application No.0055527. However, the polyester anhydrides disclosed therein are not sufficiently bioresorbable or do not possess sufficient strength and/or modulus to be suitable as load bearing bioresorbable implants.
We have now surprisingly found a novel polymeric material which overcomes or mitigates these disadvantages.
Thus according to the invention we provide a polymeric material comprising repeating units of an aromatic mesogenic moiety, a hydroiysabie moiety and a spacer moiety. The polymeric material is preferably a condensation product containing aromatic ester moieties as the mesogenic component, mixed aromatic and aliphatic anhydride moieties as the hydrolysable component and aliphatic chains as the spacer moiety. Suitably these components may be provided by a condensation product comprising both aromatic and aliphatic diacid residues or functional derivatives thereof and residues of polyfunctional nucleophilic species such as a diol or thiol. Thus the preferred polymeric materials of the present invention are poly(ester-anhydride)s. Alternatively the mesogenic component may be derived from aromatic amide moieties.
The aromatic mesogenic moiety may be a polyester moiety and is preferably a condensation product of, for example, a terephthaloyl or isophthaloyl moiety and a quinoid such as hydroquinone, methylhydroquinone, phenyihydroquinone, biphenol or dihydroxynaphthalene or derivatives thereof.
Thus the aromatic mesogenic moiety aptly comprises a moiety of formula I.
OC - R2 - CO - 0 - Ri - O - OC - R2 - CO I where R^ is:
and R2 is : or -(Q)~ A preferred mesogenic moiety comprises a moiety of the general formula II
The hydrolysable moiety may comprise any conventionally known hydrolysable group. However, a preferred hydrolysable moiety is an anhydride linkage. Such anhydrides may be the condensation product of an aliphatic diacid derivative and an aromatic diacid derivative, such as a terephthaloyi acid derivative, eg. terephthaloyi chloride or an isophthaloyl derivative such as isophthaloyl chloride.
The spacer moiety is any inert group and may preferably comprise an aliphatic chain, for example comprising methylene groups from C2 to C20. suitably from C2 to C18, and preferably from C4 toC10. Alternatively, the spacer moiety may comprise alkylene oxide units ethylene oxide, propylene oxide or tetramethyiene oxide units.
Thus according to the invention we provide a polymeric material comprising repeating units of formula III,
in which: n is an integer from 2 to 20, preferably from 2 to 16, more preferably 4 to 10, R, and R2 are as defined above and the ratio of x:y is from 1 :99 to 99:1 In a preferred embodiment R, andR2 is methyl-substitued phenyl.
According to a further feature of the invention we provide a method of manufacturing a polymeric material as hereinbefore described which comprises condensing a terephthaloyi or isophthaloyl compound and a quinoid such as hydroquinone, methylhydroquinone, phenylhydroquinone, biphenol or dihydroxynaphthalene or derivatives thereof and an aliphatic diacid or derivative thereof.
The terephthaloyi or isophthaloyl derivative is preferably an acid haiide, eg. acid chloride such as terephthaloyi or isophthaloyl chloride. Such materials are generally commercially available.
The quinoid derivative is preferably an activated hydroquinone such as the silylated derivative, eg. bis-trimethylsilyl hydroquinone. Bis-trialkylsilyl hydroquinones may be manufactured by, inter alia, reacting the respective quinoid with hexalkyldisiiazane.
Similarly, the aliphatic diacid derivative is preferably an activated diacid such as a silylated diacid, eg. comprising silyl groups as hereinbefore described.
The polymeric material of the invention is advantageous in that it may be degradable to fragments of low molecular weight, which may in itself facilitate bioresorbability. Such polymeric materials may be processed to produce high strength and high modulus materials which are useful in the manufacture of, inter alia, implantable devices, eg. implantable fixation devices such as bone fixation or prosthetic devices. The desired strength and modulus of the polymeric materials of the invention is evidenced by the presence of liquid crystal properties.
Thus according to a further feature of the invention we provide a medical fixation device comprising a polymeric material as hereinbefore described.
We further provide the use of a polymeric material as hereinbefore described in the manufacture of a medical fixation device.
We also provide a method of bone fixation which comprises attaching a fixation device as hereinbefore described to portions of existing bone.
Aptly such fixation devices are preformed to the shape of implantable prosthetic devices, such as femoral head or condylar prostheses or as a filling material, which may be suitably shaped, to replace missing or excised bone portions.
The invention will now be described but in no way limited with reference to the following Examples.
Example 1
Preparation of Bis-trimethytsilvl Methyl Hydroquinone
Methyl hydroquinone (27.53g) and hexamethyldisilazane (48.42g) were refluxed together in toluene (400ml) for 2 hours. The resultant bis-trimethylsilyl hydroquinone (75g) was isolated by vacuum distillation. Preparation of Bis-trimethylsilyl Adipic Acid
Adipic acid (36.54g) and hexamethyldisilazane (48.42g) were refluxed in toluene (400ml) for 4 hours. The resultant bis- trimethylsilyl adipate (84g) was isolated by vacuum distillation.
Terephthaloyi chloride (4.06g), bis-trimethylsilyl methyl- hydroquinone (4.3g), bis-trimethylsilyl dodecanedioate (1.5g) and benzyltriethylammonium chloride (0.01g) were weighed under nitrogen into a glass reaction vessel. The reaction mixture was heated, with stirring under nitrogen, from 90 ' C to 260 * C over a period of 3 hours after which a vacuum was applied for a further half-hour. The product was washed with dry tetrahydrofuran, dried under vacuum at 60 'C and characterised by FTIR spectral analysis, 13C-NMR spectral analysis and optical scanning under polarised light.
Figures 1 and 2, respectively, illustrate the FTIR and NMR spectra of the polymer. Figure 3 is a monochromatic reproduction of a coloured microphotograph of the polymer demonstrating the liquid crystalline properties of the polymer. The micrograph was taken between cross polars whilst the polymer was molten. The coloured region (textured region X shown in Figure 3) is evidence of a birefringent fluid which can only arise if there is molecular order in the liquid, i.e. a liquid crystalline polymer. Also illustrated in Figure 3 are thread-like structures (Y) which are typically associated with nematic type liquid crystals. Examples 2 to 5
Poly(ester-anhydride)s having the compositions shown in the following table were prepared in accordance with the method described in Example 1. Each polymer exhibited thermotropic behaviour (viz. a liquid crystalline phase in the polymer melt).
T: Terephthaloyi Chloride
M: Bis-trimethylsilyl methylhydroquinone
P: Bis-trimethylsilyl phenylhydroquinone
A: Bis-trimethyisiyl adipate
Su: Bis-trimethylsilyl suberate
Se: Bis-trimethylsilyl sebacate
D: Bis-trimethylsilyl dodecanedioate
Example 6
The method of Example 1 was used to prepare a polyester- anhydride) comprised of residues derived from 50 mole% terephthaloyi chloride, 37.5 mole% bis-trimethylsilyl hydroquinone and 12.5 mole% bis-trimethylsilyl dodecanedioate.
A disc of the polymer material was immersed in deionized water, maintained at room temperature, for one month. The structure was analysed by infared spectroscopy to investigate hydrolysis of the anhydride linkage. The FTIR spectra of the original polymer (Curve A) and the degraded polymer (Curve B) is shown in Figure 4 where it will be seen that the strong absorption band near 1790 cm"1 for Curve A has almost disappeared at that point in Curve B.

Claims

1. A biodegradable polymer comprising repeating units of an aromatic mesogenic moiety, a hydrolysable moiety and a spacer moiety.
2. A polymer as claimed in claim 1 in which the mesogenic moiety comprises aromatic ester residues.
3. A polymer as claimed in claim 1 or claim 2 in which the mesogenic moiety comprises residues of the general formula: OC - R2 - CO - 0 - RT - 0 - R2 - CO in which Rή is:
and R2 is
-<Q^ °' 4δr
4. A polymer as claimed in any one of the preceding claims in which the hydrolysable moiety comprises anhydride linkages.
5. A polymer as claimed in any one of the preceeding claims in which the hydrolysable moiety comprises residues of mixed aromatic-aliphatic anhydride.
6. A polymer as claimed in any one of the preceding claims formed by the condensation of aromatic and aliphatic diacids or functional derivatives thereof with a nucleophilic compound.
7. A polymer as claimed in claim 6 in which the nucleophilic compound is an aromatic diol or thiol.
8. A polymer as claimed in any one of the preceding claims having repeating units if the general formula:
9. [(-OC-R2-CO-0-RrO)Jr\(OC-R2-CO-0-OC-{CH2)n-COO)y] in which n is an integer from 2 to 20; R, and R2 are as defined in claim 3 and the ratio of x:y is from 1 :99 to 99: 1 ,
10. A medical fixation device comprising a biodegradable polymer as defined in any one of the preceding claims.
11. A device as claimed in claim 10 comprising a prosthesis or a bone filling material.
EP97926102A 1996-06-15 1997-06-12 Biodegradable liquid crystalline polymers Withdrawn EP0909301A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB9612581 1996-06-15
GBGB9612581.0A GB9612581D0 (en) 1996-06-15 1996-06-15 Polymeric materials
PCT/GB1997/001586 WO1997048782A1 (en) 1996-06-15 1997-06-12 Biodegradable liquid crystalline polymers

Publications (1)

Publication Number Publication Date
EP0909301A1 true EP0909301A1 (en) 1999-04-21

Family

ID=10795377

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97926102A Withdrawn EP0909301A1 (en) 1996-06-15 1997-06-12 Biodegradable liquid crystalline polymers

Country Status (5)

Country Link
EP (1) EP0909301A1 (en)
AU (1) AU3098997A (en)
CA (1) CA2257923A1 (en)
GB (1) GB9612581D0 (en)
WO (1) WO1997048782A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7182884B2 (en) * 2003-01-30 2007-02-27 Mitsuru Akashi Bio-liquid crystal polymer and shaped material using same
US7582078B2 (en) 2006-02-14 2009-09-01 Boston Scientific Scimed, Inc. Medical device employing liquid crystal block copolymers and method of making the same
US7662129B2 (en) 2006-02-14 2010-02-16 Boston Scientific Scimed, Inc. Medical device employing liquid crystal block copolymers and method of making the same
JP5581202B2 (en) * 2007-05-02 2014-08-27 タイレックス・インコーポレイテッド Dihydroxybenzoate polymer and use thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0246341B1 (en) * 1986-05-20 1990-04-11 Massachusetts Institute Of Technology Bioerodible articles useful as implants and prostheses having predictable degradation rates
EP0350127A3 (en) * 1988-07-08 1990-04-04 Dsm N.V. Plastic device for orthopedic uses
JPH0234631A (en) * 1988-07-23 1990-02-05 Ajinomoto Co Inc Thrmotropic liquid crystal polypeptide
US5321113A (en) * 1993-05-14 1994-06-14 Ethicon, Inc. Copolymers of an aromatic anhydride and aliphatic ester
JPH0859586A (en) * 1994-08-25 1996-03-05 Aibaitsu Kk N-(meth)acryloyl-leucine alkyl ester, its production and its polymer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9748782A1 *

Also Published As

Publication number Publication date
GB9612581D0 (en) 1996-08-21
CA2257923A1 (en) 1997-12-24
AU3098997A (en) 1998-01-07
WO1997048782A1 (en) 1997-12-24

Similar Documents

Publication Publication Date Title
US5644002A (en) Absorbable polyalkylene diglycolates
US5321113A (en) Copolymers of an aromatic anhydride and aliphatic ester
AU719104B2 (en) Absorbable polyoxaesters
CA2170941C (en) Absorbable polyoxaesters
US5665831A (en) Biocompatible block copolymer
US5658995A (en) Copolymers of tyrosine-based polycarbonate and poly(alkylene oxide)
US4888413A (en) Poly(propylene glycol fumarate) compositions for biomedical applications
US6048521A (en) Copolymers of tyrosine-based polyarlates and poly(alkylene oxides)
US5607687A (en) Polymer blends containing absorbable polyoxaesters
US20010046505A1 (en) Copolymers of tyrosine-based polyarylates and poly(alkylene oxides)
US5688900A (en) Absorbable polyalkylene diglycolates
EP1874525B1 (en) Hydrophilic/hydrophobic polymer networks based on poly(caprolactone fumarate), poly(ethylene glycol fumarate), and copolymers thereof
EP0617712B1 (en) Copolymer of lactone and carbonate and process for the preparation of such a copolymer
US7714077B2 (en) Triblock copolymer, method for producing the same, and biocompatible material
US5756652A (en) Poly (ester-anhydrides) and intermediates therefor
WO1997048782A1 (en) Biodegradable liquid crystalline polymers
EP0771849B1 (en) Polymer blends containing polyoxaesters and lactone polymers
Chen et al. Hydrolytic degradation of polyester–polyether block copolymer based on polycaprolactone/poly (ethylene glycol)/polylactide
JPH06508388A (en) Copolymers based on cyclic esters and their use as surgical implants
JP3345631B2 (en) Method for producing biodegradable resin
KR100288002B1 (en) Star copolymer of polyelactide and polyethylene oxide
Ciardelli et al. Synthesis of fluorescence‐labelled short‐chain polyester segments for the investigation of bioresorbable poly (ester‐urethane) s
Lee et al. Synthesis and Properties of Triblock and Multiblock Copolymers Consisting of Poly (L-lactide) and Poly (oxyethylene-co-oxypropylene)
MXPA97003652A (en) Absalbib polyalykylene diglycollates

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19990115

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 19991126

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: SMITH & NEPHEW PLC

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20000608