Biodegradable composite scaffold for repairing defects in load-bearing bones

Patent metadata

Field	Value
Publication number	US-10238772-B2
Application number	US-201414216451-A
Country	US
Kind code	B2
Filing date	Mar 17, 2014
Priority date	Mar 15, 2013
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A tissue scaffold for repair and regeneration of bone hard tissue or muscle, skin, or organ soft tissue, including load-bearing bone tissue, the scaffold comprising a core of biocompatible, biodegradable inorganic glass fibers; and a biocompatible, biodegradable, flexible polymer film surrounding the core and adhered to the core.

First claim

The invention claimed is:

1. A tissue scaffold for repair and regeneration of bone hard tissue or muscle, skin, or organ soft tissue, including load-bearing bone tissue, the scaffold comprising:
a core consisting of biocompatible, biodegradable inorganic glass fibers; and
only a biocompatible, biodegradable, flexible polymer film surrounding the core and adhered to the core;
wherein the core with surrounding polymer film is characterized by a flexural strength of at least about 40 MPa; and
wherein the core is characterized by open and interconnected porosity to facilitate fluid flow into and lengthwise within the scaffold.

2. The scaffold of claim 1 wherein the polymer film has a thickness between about 5 microns and about 1000 microns.

3. The scaffold of claim 1 wherein the polymer film encapsulates the scaffold body along some fraction of its length but not at its ends, so the scaffold body is open with its core exposed at its ends.

4. The scaffold of the claim 1 wherein the core has a flexural strength of less than about 40 MPa.

5. The scaffold of the claim 1 wherein the core has a flexural strength of less than about 10 MPa.

6. The scaffold of the claim 1 wherein the core has a flexural strength which is less than about 50% of the flexural strength of the scaffold comprising the core and the polymer film.

7. The scaffold of claim 1 wherein the core has a flexural strength which is less than about 10% of the flexural strength of the scaffold comprising the core and the polymer film.

8. The scaffold of claim 1 wherein the fibers of the core are bonded together.

9. The scaffold of claim 1 wherein the fibers of the core are thermally fused together.

10. The scaffold of claim 1 wherein at least about 75 vol % of the fibers are longitudinally co-aligned and lie generally lengthwise along the scaffold central axis, are generally free of helical orientation about the scaffold central axis, and are arranged to define open channels within the scaffold which allow fluid flow into and lengthwise within the scaffold.

11. The scaffold of claim 1 wherein the fibers of the core consist of hollow glass fibers and solid glass fibers for porosity and penetration of body fluids into the scaffold.

12. The scaffold of claim 1 wherein the polymer film is selectively perforated or porous to allow body fluids to penetrate.

13. The scaffold of claim 1 wherein the fibers of the core consist of a mixture of biodegradable glass fibers of different chemical composition that degrade in-vivo at different rates, and which can release different chemical elements that are osteogenic or angiogenic or antimicrobial.

14. The scaffold of claim 1 wherein the polymeric film is a composite film having a microporosity and which contains biodegradable glass particles, fibers, or spheres such that as the particles, fibers, or spheres react in-vivo there is an increase in the microporosity of the film to facilitate greater body fluid ingress.

15. The scaffold of claim 1 wherein the core fibers consist of glass fibers with a cross section that varies along a length of the fibers, being larger at certain locations than at other locations.

16. The scaffold of claim 1 wherein:
the polymer film has a thickness between about 5 microns and about 1000 microns;
the polymer film encapsulates the scaffold body along some fraction of its length but not at its ends, so the scaffold body is open with its core exposed at locations along its length and at its ends;
the core has a flexural strength of less than about 40 MPa;
the flexural strength of the core is less than about 50% of the flexural strength of the composite scaffold comprising the core and the polymer film;
the fibers of the core are bonded together.

17. The scaffold of claim 1 wherein:
the polymer film has a thickness between about 5 microns and about 1000 microns;
the polymer film encapsulates the scaffold body along some fraction of its length but not at its ends, so the scaffold body is open with its core exposed at locations along its length and at its ends;
the core has a flexural strength less than about 40 MPa;
the flexural strength of the core is less than about 10% of the flexural strength of the composite scaffold comprising the core and the polymer film;
the fibers of the core are bonded together.

18. The scaffold of claim 1 wherein the polymer film is wrapped around the core and adhered to the core.

19. The scaffold of claim 18 wherein the fibers of the core are thermally fused together.

20. The scaffold of claim 1 wherein the polymer film comprises a ductile polymer.

21. The scaffold of claim 1 wherein the interconnected porosity is from about 10 vol % to about 35 vol %.

22. The scaffold of claim 1 consisting of:
the core, wherein the core consists of biocompatible, biodegradable inorganic glass fibers; and
the biocompatible, biodegradable, flexible polymer film surrounding the core and adhered to the core.

23. The scaffold of claim 1 wherein the fibers of the core are longitudinally co-aligned.

24. The scaffold of claim 1 wherein the fibers of the core have a diameter between about 20 microns and about 5,000 microns.

25. The scaffold of claim 1 wherein the fibers of the core have a length between about 6 mm and about 15 cm.

26. The scaffold of claim 1 wherein the fibers of the core have a length which is at least about 10 times the diameter of the fibers of the core.

27. The scaffold of claim 1 wherein at least about 85 vol % of the fibers of the core extend the entire length of the scaffold.

28. The scaffold of claim 1 wherein the core consists of glass fibers having a diameter between 100 and 450 microns.

29. The scaffold of claim 1 wherein the polymer film has a thickness between 200 and 600 microns.

30. The scaffold of claim 1 wherein the polymer film is adhered to the core by wrapping the film around the core followed by heating, or by spraying liquid polymer on the core, by painting of the film on the core, or by dipping the core into liquid polymer followed by hardening.

31. A tissue scaffold for repair and regeneration of bone hard tissue or muscle, skin, or organ soft tissue, including load-bearing bone tissue, the scaffold comprising:
a core consisting of biocompatible, biodegradable inorganic components selected from the group consisting of longitudinally aligned fibers, randomly oriented fibers, and randomly oriented glass particles; and
only a biocompatible, biodegradable, flexible polymer film surrounding the core and adhered to the core;
wherein the core with the surrounding polymer film is characterized by a flexural strength of at least about 40 MPa; and
wherein the core is characterized by open and interconnected porosity to facilitate fluid flow into and lengthwise within the scaffold.

32. A tissue scaffold for repair and regeneration of bone hard tissue or muscle, skin, or organ soft tissue, including load-bearing bone tissue, the scaffold consisting of:
a core consisting of biocompatible, biodegradable inorganic glass fibers or consisting of biocompatible, biodegradable inorganic components selected from the group consisting of longitudinally aligned fibers, randomly oriented fibers, and randomly oriented glass particles; and
a biocompatible, biodegradable, flexible polymer film h

Assignees

• Day Delbert E
• Mohammadkhah Ali
• Univ Missouri

Inventors

• Day Delbert E
• Mohammadkhah Ali

Classifications

• A61L27/34

  Macromolecular materials · CPC title

• A61L27/56

  Porous materials, {e.g. foams or sponges} · CPC title

• A61L27/58

  Materials at least partially resorbable by the body · CPC title

• A61L2430/02

  for reconstruction of bones; weight-bearing implants · CPC title

• A61L27/427 Primary

  of other specific inorganic materials not covered by A61L27/422 or A61L27/425 · CPC title