Implant material and process for producing the same

• US 20040258732A1
• Filed: 05/20/2004
• Published: 12/23/2004
• Est. Priority Date: 11/27/2001
• Status: Active Grant

• Current Assignee: Teijin Medical Technologies Co., Ltd. (Teijin Limited)
• Original Assignee: Takiron Company Limited (Itochu Corporation)
• Inventors: Shikinami, Yasuo
• Granted Patent: US 8,119,152 B2
• Time in Patent Office: Days
• US Class Current: 424/426
• CPC Class Codes: A61B 17/8085 with pliable or malleable elements or having a mesh-like structure, e.g. small strips A61B17/8071, A61B17/8076 take precedence
• CPC Class Codes: A61B 17/823 for the sternum
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/2875 Skull or cranium A61F2/2803 and A61F2/3099 take precedence
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30148 lozenge- or diamond-shaped
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30733 Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30909 Nets
• CPC Class Codes: A61F 2002/30971 Laminates, i.e. layered products
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61L 27/446 : with other specific inorganic fillers other than those covered by A61L27/443 or A61L27/46
• CPC Class Codes: A61L 27/46 : with phosphorus-containing inorganic fillers
• CPC Class Codes: A61L 27/56 : Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 27/58 : Materials at least partially resorbable by the body
• CPC Class Codes: B29C 43/003 : characterised by the choice of material
• CPC Class Codes: B29K 2105/04 : cellular or porous
• CPC Class Codes: B29K 2105/06 : containing reinforcements, fillers or inserts
• CPC Class Codes: B29L 2031/7532 : Artificial members, protheses
• CPC Class Codes: D04B 21/16 : incorporating synthetic threads

Abstract

The object of the invention is to provide an implant material comprising a bioactive and degradable and absorbable organic-inorganic complex porous article and a production method thereof.

The invention is,

an implant material comprising an organic-inorganic complex porous article which is a biodegradable and bioabsorbable bioactive porous article in which a bioactive bioceramics powder is uniformly dispersed in a biodegradable and bioabsorbable polymer, wherein it has continuous pores and the bioceramics powder is partly exposed to the pore inner surface or the pore inner surface and the porous article surface, and

a method for producing an implant material comprising an organic-inorganic complex porous article, characterized in that a nonwoven fabric-like fiber aggregate is formed from a mixed solution prepared by dissolving a biodegradable and bioabsorbable polymer in a volatile solvent and dispersing a bioactive bioceramics powder therein, this is formed into a porous fiber aggregate molding by compression-molding it under heating, the fiber aggregate molding is soaked in the volatile solvent, and then said solvent is removed.

Claims

1. An implant material comprising an organic-inorganic complex porous article which is a biodegradable and bioabsorbable bioactive porous article in which a bioactive bioceramics powder is uniformly dispersed in a biodegradable and bioabsorbable polymer, wherein it has continuous pores and the bioceramics powder is partly exposed to the pore inner surface or the pore inner surface and the porous article surface.

16. The implant material described in any one of claims 1 to 15, wherein porosity of the aforementioned porous article is from 50 to 90%, and the continuous pores occupy from 50 to 90% of the total pores.

17. The implant material described in any one of claims 1 to 15, wherein pore size of the continuous pores of the aforementioned porous article is approximately from 100 to 400 μ

m.

18. The implant material described in any one of claims 1 to 15, wherein the biodegradable and bioabsorbable polymer of the aforementioned porous article is any one of a totally absorbable poly-D,L-lactic acid, a block copolymer of L-lactic acid with D,L-lactic acid, a copolymer of lactic acid with glycolic acid, a copolymer of lactic acid with p-dioxanone and a block copolymer of lactic acid with ethylene glycol.

19. The implant material described in claim 1 or any one of claims 3 to 15, wherein percentage content of bioceramics powder of the aforementioned porous article is from 60 to 90% by weight.

20. The implant material described in any one of claims 1 to 15, wherein percentage content of bioceramics powder of the aforementioned porous article is from 50 to 85% by volume.

21. The implant material described in any one of claims 1 to 15, wherein average particle size of the bioceramics powder contained in the aforementioned porous article is from 0.2 to 10 μ

m.

22. The implant material described in any one of claims 1 to 15, wherein the bioceramics powder contained in the aforementioned porous article is any one of powders of totally absorbable un-calcined or un-sintered hydroxyapatite, dicalcium phosphate, tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, calcite, ceravital, diopside and natural coral.

23. The implant material described in any one of claims 1 to 15, wherein compressive strength of the aforementioned porous article is from 1 to 5 MPa.

24. The implant material described in any one of claims 1 to 15, wherein an oxidation treatment such as corona discharge or plasma treatment is applied to the aforementioned porous article.

25. The implant material described in any one of claims 1 to 3, wherein the aforementioned porous article has a three dimensional solid shape having a thickness of from 1 to 50 mm.

2. An implant material comprising an organic-inorganic complex porous article which is a biodegradable and bioabsorbable bioactive porous article in which a bioactive bioceramics powder is uniformly dispersed in a biodegradable and bioabsorbable polymer, wherein it has continuous pores and percentage content of the bioceramics powder is from 60 to 90% by weight.

3. An implant material comprising a bioactive organic-inorganic complex porous article which is obtained by forming a nonwoven fabric-like fiber aggregate from a mixed solution prepared by dissolving a biodegradable and bioabsorbable polymer in a volatile solvent and dispersing a bioactive bioceramics powder therein, forming this into a porous fiber aggregate molding by compression-molding it under heating, soaking the fiber aggregate molding in a volatile solvent, and then removing said solvent.

4. An implant material comprising an organic-inorganic complex porous article which is a biodegradable and bioabsorbable bioactive porous article in which a bioactive bioceramics powder is uniformly dispersed in a biodegradable and bioabsorbable polymer, wherein it has continuous pores and the bioceramics powder is partly exposed to the pore inner surface or the pore inner surface and the porous article surface, and other biodegradable and bioabsorbable member united thereto.

5. The implant material described in claim 4, wherein the other biodegradable and bioabsorbable member is a pin for bone fixation, said pin is united by penetrating through the aforementioned porous article, and both termini of the pin are stuck out from the aforementioned porous article.

6. The implant material described in claim 4, wherein the other biodegradable and bioabsorbable member is a matrix having a cavity opening into the outside and comprising a biodegradable and bioabsorbable polymer containing a bioactive bioceramics powder, the aforementioned porous article is united by being packed in the cavity of said matrix and the aforementioned porous article is partly exposed from said matrix.

7. The implant material described in claim 6, wherein the aforementioned porous article is also superposed and united in a flat shape on the upper and lower sides of the aforementioned matrix.

8. The implant material described in claim 6, wherein the aforementioned matrix is formed into a shape of any one of a rectangular prism shape having cavity inlets on its all four upper, lower, left and right sides, an annular shape having a cavity inside thereof and a cylindrical shape having a cavity inside thereof and two or more cavity inlets arranged on the peripheral face.

9. The implant material described in claim 4, wherein the aforementioned other biodegradable and bioabsorbable member is a skin layer comprising a biodegradable and bioabsorbable polymer containing a bioactive bioceramics powder, and said skin layer is united by superposing on a part of the surface of the aforementioned porous article in a block shape.

10. The implant material described in claim 4, wherein the aforementioned other biodegradable and bioabsorbable member is a net-shaped body comprising a biodegradable and bioabsorbable polymer containing a bioactive bioceramics powder, and the aforementioned porous article is united by being packed in the mesh of said net-shaped body.

11. The implant material described in claim 10, wherein the aforementioned porous article is also superposed and united in a layer shape on one side or both sides of the aforementioned net-shaped body.

12. The implant material described in claim 10, wherein the aforementioned net-shaped body is concave-curved or convex-curved, and the aforementioned porous article is also united by being filled inside of the aforementioned net-shaped body.

13. The implant material described in claim 10, wherein the aforementioned net-shaped body is a product prepared by forming meshes on a sheet or plate of a biodegradable and bioabsorbable polymer containing a bioceramics powder, and said sheet or plate is prepared by once forging at a temperature within the range of from glass transition temperature of the biodegradable and bioabsorbable polymer to its melting temperature and then further forging it at said temperature range by changing the direction.

14. An implant material for artificial cartilage, comprising an integrated body prepared by laminating an organic-inorganic complex porous article which is a biodegradable and bioabsorbable bioactive porous article in which a bioactive bioceramics powder is uniformly dispersed in a biodegradable and bioabsorbable polymer, wherein it has continuous pores and the bioceramics powder is partly exposed to the pore inner surface or the pore inner surface and the porous article surface, on at least one side of a core material comprising a texture structure body prepared by converting organic fibers into a multi-axial three dimensional weave texture or knit texture of three or more axes or a complex texture thereof.

15. The implant material described in claim 14, wherein fibers of the aforementioned core material are prepared by coating core fibers of an ultra-high molecular weight polyethylene with the coating of a low density polyethylene.

26. A method for producing an implant material comprising an organic-inorganic complex porous article, characterized in that a nonwoven fabric-like fiber aggregate is formed from a mixed solution prepared by dissolving a biodegradable and bioabsorbable polymer in a volatile solvent and dispersing a bioactive bioceramics powder therein, this is formed into a porous fiber aggregate molding by compression-molding it under heating, the fiber aggregate molding is soaked in the volatile solvent, and then said solvent is removed.

27. The production method described in claim 26, characterized in that in carrying out molding of the porous fiber aggregate molding by compression-molding the aforementioned fiber aggregate under heating, a preliminarily molded product having continued voids is firstly prepared by solidifying the aforementioned fiber aggregate under heating and compression, and the preliminarily molded product is then subjected to compression molding under a pressure higher than the pressure at the time of preparing this preliminarily molded product.

28. The production method described in claim 26, characterized in that in carrying out soaking of the aforementioned fiber aggregate molding in a volatile solvent, the aforementioned fiber aggregate molding is packed in a predetermined mold having a large number of pores and soaked while maintaining the shape.