Method of fabricating a tissue engineering scaffold

• US 7,998,380 B2
• Filed: 07/13/2007
• Issued: 08/16/2011
• Est. Priority Date: 07/13/2007
• Status: Active Grant

• Current Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Original Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Inventors: Kramschuster, Adam J., Turng, Lih-Sheng
• Primary Examiner(s): Johnson; Christina
• Assistant Examiner(s): YI, STELLA KIM
• Application Number:
  US11/777,555
• Publication Number:
  US 20090017094A1
• Time in Patent Office: 1,495 Days
• Field of Search: 264/413, 264/36.11, 264/37.15, 264/48, 264/637, 264/651, 264/86, 264/288.8, 264/916, 264/645, 264/513, 264/537, 264/297.2
• US Class Current: 264/49
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10S 264/916 From porous material containing articles, e.g. sponge, foam

Abstract

A method of fabricating a highly porous structure is provided. The method includes the step of compounding a biodegradable polymer, a water-soluble polymer and a porogen to form a composite blend. A foaming agent is dissolved into the composite blend and the composite blend is injected into a mold so as to form the structure. Thereafter, the structure is removed from the mold and leached in a fluid.

Claims

1. A method of fabricating a highly porous structure, comprising the steps of:

blending a biodegradable polymer, a water-soluble polymer and a porogen to form a composite blend;

introducing a gas in a supercritical state into composite blend;

mixing the gas into the composite blend to a form a single-phase solution prior to injecting the composite blend into the mold;

injecting the single-phase solution into a mold;

processing the single-phase solution in the mold to generate the structure; and

leaching the structure in a fluid for a time period such that the water-soluble polymer is extracted from the structure.

2. The method of claim 1 wherein the gas is carbon dioxide.

3. The method of claim 1 wherein the porogen is sodium chloride.

4. The method of claim 1 wherein the biodegradable polymer is polylactide.

5. The method of claim 1 wherein the water-soluble polymer is polyvinyl alcohol.

6. The method of claim 1 comprising the additional step of sieving the porogen to a particle size of less than 300 microns.

7. A method of fabricating a highly porous structure, comprising the steps of:

compounding a biodegradable polymer, a water-soluble polymer and a porogen to form a composite blend;

dissolving a foaming agent into the composite blend;

mixing the foaming agent and composite blend to form a single-phase solution;

injecting the single-phase solution into a mold to form the structure; and

leaching the structure in a fluid such that the water-soluble polymer is extracted from the structure.

8. The method of claim 7 wherein the step of dissolving a foaming agent into the composite blend includes the additional step of introducing a gas in a supercritical state into the composite blend.

9. The method of claim 8 wherein the gas is carbon dioxide.

10. The method of claim 7 wherein the porogen is sodium chloride.

11. The method of claim 7 wherein the biodegradable polymer is polylactide.

12. The method of claim 7 wherein the water-soluble polymer is polyvinyl alcohol.

13. The method of claim 7 comprising the additional step of sieving the porogen to a particle size of less than 300 microns.

14. A method of fabricating a highly porous structure, comprising the steps of:

introducing a foaming agent into a compound including a biodegradable polymer, a water-soluble polymer and a porogen;

mixing the foaming agent and the compound within a barrel of an injection molding machine;

injecting the mixture of the foaming agent and the compound into a mold under pressure;

processing the compound in the mold to form the structure; and

leaching the structure in a fluid such that the water-soluble polymer is extracted from the structure.

15. The method of claim 14 wherein the step of introducing a foaming agent includes the additional step of:

introducing a gas in a supercritical state into the compound.

16. The method of claim 15 wherein the gas is carbon dioxide.

17. The method of claim 14 wherein the porogen is sodium chloride.

18. The method of claim 14 wherein the biodegradable polymer is polylactide.

19. The method of claim 14 wherein the water-soluble polymer is polyvinyl alcohol.

20. The method of claim 14 comprising the additional step of sieving the porogen to a particle size of less than 300 microns.