Devices and Methods for Tissue Engineering

• US 20110106255A1
• Filed: 07/08/2010
• Published: 05/05/2011
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: Novum Medical Incorporated
• Original Assignee: Bio2 Technologies, Inc.
• Inventors: WALLEN, ADAM, NUUTINEN, JUHA-PEKKA, LIU, JAMES JENQ
• Granted Patent: US 8,337,876 B2
• Time in Patent Office: Days
• US Class Current: 623/16.11
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30734 Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2002/4495 having a fabric structure, e.g. made from wires or fibres
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2310/00329 Glasses, e.g. bioglass
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 2430/38 for reconstruction of the spine, vertebrae or intervertebral discs
• CPC Class Codes: A61L 27/10 Ceramics or glasses
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• 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: C03C 10/0009 containing silica as main constituent
• CPC Class Codes: C03C 11/00 : Multi-cellular glass ; Porous or hollow glass or glass particles
• CPC Class Codes: C03C 13/006 : Glass-ceramics fibres
• CPC Class Codes: C03C 2204/00 : Glasses, glazes or enamels with special properties
• CPC Class Codes: C03C 2213/02 : Biodegradable glass fibres
• CPC Class Codes: C03C 4/0014 : Biodegradable glass
• CPC Class Codes: Y10T 428/249928 : Fiber embedded in a ceramic, glass, or carbon matrix

Abstract

A resorbable tissue scaffold fabricated from bioactive glass fiber forms a rigid three-dimensional porous matrix having a bioactive composition. Porosity in the form of interconnected pore space is provided by the space between the bioactive glass fiber in the porous matrix. Strength of the bioresorbable matrix is provided by bioactive glass that fuses and bonds the bioactive glass fiber into the rigid three-dimensional matrix. The resorbable tissue scaffold supports tissue in-growth to provide osteoconductivity as a resorbable tissue scaffold, used for the repair of damaged and/or diseased bone tissue.

Claims

1. A resorbable three-dimensional tissue scaffold comprising:

bioactive glass fibers;

bioactive glass bonding to at least a portion of the bioactive glass fibers; and

pore space within the three-dimensional tissue scaffold predetermined by volatile components removed during the bioactive glass bonding to the bioactive glass fibers,

wherein the pore space creates a porosity between about 40% and about 85% in the resorbable three-dimensional tissue scaffold.

2. The tissue scaffold according to claim 1 wherein the bioactive glass fibers and the bioactive glass have a uniform composition.

3. The tissue scaffold according to claim 1 wherein the pore space within the three-dimensional tissue scaffold has a pore size between about 100 μ

m and about 500 μ

m.

5. The tissue scaffold according to claim 1 wherein a plurality of the bioactive glass fibers are bonded to adjacent bioactive glass fibers providing bundles of bonded bioactive glass fibers.

6. The tissue scaffold according to claim 1 wherein the bioactive glass fibers comprise sodium carbonate, calcium carbonate, phosphorus pentoxide, about 45 mol % to about 60 mol % silica, and an about 2 to an about 10 molar ratio of calcium to phosphate.

7. The tissue scaffold according to claim 1 wherein the bioactive glass fibers comprise 13-93 glass fiber.

8. The tissue scaffold according to claim 1 wherein the bioactive glass fibers have a diameter ranging from about 1 μ

m to about 200 μ

m.

9. The tissue scaffold according to claim 8 wherein the bioactive glass fibers have a diameter ranging from about 5 μ

m to about 100 μ

m.

4. The tissue scaffold according to claim 4 wherein the pore size has a bi-modal size distribution.

10. A bioactive tissue scaffold comprising:

a rigid three-dimensional matrix of a bioactive composition formed from a process comprising;

mixing a bioactive fiber, a binder, a bonding agent, a pore former, and a liquid into a plastically formable batch;

forming the plastically formable batch into a shaped object;

drying the shaped object to remove the liquid;

removing the binder;

removing the pore former; and

heating the shaped object to fuse and bond the bioactive fiber into the rigid three-dimensional matrix using the bonding agent with pore space defined by the pore former.

11. The bioactive tissue scaffold according to claim 10 wherein the bonding agent is a bioactive glass powder.

12. The bioactive tissue scaffold according to claim 11 wherein the bioactive glass powder is substantially the same composition as the bioactive fiber.

13. The bioactive tissue scaffold according to claim 11 wherein the bioactive fiber comprises sodium carbonate, calcium carbonate, phosphorus pentoxide, about 45 mol % to about 60 mol % silica and an about 2 to an about 10 molar ratio of calcium to phosphate.

14. The bioactive tissue scaffold according to claim 11 wherein the bioactive fiber comprises a mixture of bioactive fiber having different compositions.

15. The bioactive tissue scaffold according to claim 11 wherein the bonding agent is a bioactive glass powder having a particle size between about 1 to about 1000 times smaller than the diameter of the bioactive glass fiber.

16. The bioactive tissue scaffold according to claim 10 wherein the pore former has a particle size between about 0.1 and about 100 times the bioactive fiber diameter.

17. A resorbable tissue scaffold comprising:

bioactive glass fiber bonded into a rigid three-dimensional porous matrix; and

pore space within the rigid three-dimensional porous matrix predetermined by volatile components removed during formation of the three-dimensional porous matrix,

wherein the pore space creates a porosity between about 40% and about 85% in the resorbable tissue scaffold.

18. The resorbable tissue scaffold according to claim 17 wherein the pore space within the rigid three-dimensional porous matrix has a pore size between about 100 μ

m and about 500 μ

m.

19. The resorbable tissue scaffold according to claim 18 wherein the pore size has a bi-modal size distribution.

20. The resorbable tissue scaffold according to claim 17 wherein a plurality of the bioactive glass fibers are bonded to adjacent bioactive glass fibers providing bundles of bonded bioactive glass fibers.

21. The resorbable tissue scaffold according to claim 17 wherein the bioactive glass fibers comprise sodium carbonate, calcium carbonate, phosphorus pentoxide, about 45 mol % to about 60 mol % silica, and an about 2 to an about 10 molar ratio of calcium to phosphate.

22. The resorbable tissue scaffold according to claim 17 wherein the bioactive glass fibers comprise 13-93 glass fiber.

23. The resorbable tissue scaffold according to claim 17 wherein the bioactive glass fibers have a diameter ranging from about 1 μ

m to about 200 μ

m.

24. The resorbable tissue scaffold according to claim 23 wherein the bioactive glass fibers have a diameter ranging from about 5 μ

m to about 100 μ

m.

25. A method of filling a defect in a bone comprising:

filling a space in the bone with a resorbable tissue scaffold comprising bioactive fibers bonded into a porous matrix, the porous matrix having a pore size distribution to facilitate in-growth of bone tissue; and

attaching the resorbable tissue scaffold to the bone.

26. The method according to claim 25 wherein the bone is a vertebrae.

27. The method according to claim 25 wherein the resorbable tissue scaffold is substantially wedge-shaped and the space is an osteotomy.