Modified porous materials and method of forming the same

• US 7,323,208 B2
• Filed: 11/30/2004
• Issued: 01/29/2008
• Est. Priority Date: 11/30/2004
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Liu, Xiaohua, Ma, Peter X.
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US10/999,459
• Publication Number:
  US 20060115644A1
• Time in Patent Office: 1,155 Days
• Field of Search: None
• US Class Current: 427/2.1
• CPC Class Codes: C08J 9/36 After-treatment C08J9/22 takes precedence
• CPC Class Codes: Y10T 428/249967 Inorganic matrix in void-containing component
• CPC Class Codes: Y10T 428/249991 Synthetic resin or natural rubbers
• CPC Class Codes: Y10T 428/249992 Linear or thermoplastic
• CPC Class Codes: Y10T 428/249993 Hydrocarbon polymer

Abstract

Modified porous materials are disclosed having interconnected, complexly shaped three-dimensional surfaces. The modification is accomplished by crosslinking the three-dimensional surfaces and/or by coating the three-dimensional surfaces with a layer of a predetermined material. The porous materials are macro structures including at least one of nano-features, micro-features, and combinations thereof. The modifying accomplishes changing surface properties of the porous materials, changing the three-dimensional surfaces, and/or rendering the porous materials substantially stable in a predetermined environment.

Claims

1. A method of modifying porous materials having interconnected, complexly shaped three-dimensional surfaces, the method comprising the step of:

pretreating the porous materials with an ethanol solution or a surface charge modifying agent; and

stabilizing the pretreated porous materials by directly coating the three-dimensional surfaces with a layer of gelatin;

wherein the porous materials are macro structures including at least one of nano-features, micro-features, and combinations thereof, and wherein the porous materials are substantially stable in a predetermined environment.

2. The method as defined in claim 1 wherein the gelatin coating layer ranges in thickness between about 10⁻

10 meters and about 10<sup>−

3</sup> meters.

3. The method as defined in claim 2 wherein the gelatin coating layer ranges in thickness between about 10⁻

9 meters and about 10<sup>−

6</sup> meters.

4. The method as defined in claim 1 wherein the porous materials comprise at least one of synthetic macromolecules;

natural macromolecules;

substantially non-macromolecular materials;

natural macromolecule-containing materials;

synthetic macromolecule-containing materials;

oligomeric materials;

fragments of macromolecules;

macromolecule-containing composites; and

mixtures thereof.

5. The method as defined in claim 4 wherein the macromolecule-containing composite has as a component thereof at least one of ceramic materials, metal materials, inert additives, active additives, and mixtures thereof.

6. The method as defined in claim 1, further comprising the step of crosslinking the gelatin coating layer, wherein the porous materials comprise at least one of:

substantially non-macromolecular materials;

natural macromolecules;

synthetic macromolecules;

natural macromolecule-containing materials;

synthetic macromolecule-containing materials;

oligomeric materials;

fragments of macromolecules; and

mixtures thereof.

7. The method as defined in claim 4 wherein the synthetic macromolecules are polymeric materials, and wherein the method further comprises the step of synthesizing the polymeric materials in situ.

8. The method as defined in claim 1 wherein the coating is accomplished by at least one of mechanical application;

thermal application;

adhering;

self assembling;

molecular entrapment;

chemical bonding; and

combinations thereof.

9. The method as defined in claim 1 wherein the gelatin coating layer is different from the porous materials.

10. The method as defined in claim 9 wherein the gelatin coating layer is not substantially stable in the predetermined environment, and wherein the method further comprises the step of crossliniking the gelatin coating layer, thereby rendering the gelatin coating layer substantially stable in the predetermined environment.

11. The method as defined in claim 9 wherein the porous materials are formed from biodegradable materials adapted for tissue regeneration.

12. The method as defined in claim 11 wherein the biodegradable materials are at least one of poly(L-lactic acid) (PLLA), polyglycolic acid (PGA), poly(lactide-co-glycolide) (PLGA), and mixtures thereof.

13. The method as defined in claim 9 wherein the porous materials comprise poly(L-lactic acid) (PLLA).

14. Modified porous materials formed by the process of claim 1.

15. The method as defined in claim 1 wherein the porous materials are pretreated with the ethanol solution, and wherein the method further comprises:

dissolving the gelatin in a solvent mixture, thereby forming a gelatin solution;

soaking the pretreated porous materials in the gelatin solution, thereby forming the gelatin coating layer; and

cooling the coated porous materials.

16. The method as defined in claim 15 wherein the solvent mixture includes dioxane and water.

17. The method as defined in claim 15, further comprising chemically crossliniking the gelatin coating layer with ethyl-3-(3-dimethylaminopropyl) carbodiimide HCl and N-hydroxy-succinimide.

18. The method as defined in claim 1 wherein the porous materials are pretreated with the surface charge modifying agent, and wherein the surface charge modifying agent is poly(diallyldimethylammonium chloride).

19. The method as defined in claim 18 wherein the pretreatment results in the porous materials having positively charged surfaces, and wherein the method further comprises exposing the pretreated porous materials to a gelatin solution, thereby forming the gelatin coating layer.

20. The method as defined in claim 19, further comprising:

treating the gelatin coating layer by exposing the porous materials having the gelatin coating layer thereon to poly(diallyldimethylammonium chloride); and

exposing the treated porous materials to the gelatin solution, thereby forming a second gelatin coating layer.

21. A method of modifying porous materials having interconnected, complexly shaped three-dimensional surfaces, the method comprising the step of:

pretreating the porous materials with an ethanol solution or a surface charge modifying agent; and

accomplishing the modifying by directly coating the three-dimensional surfaces with a layer of gelatin

wherein the porous materials are macro structures including at least one of nano-features, micro-features, and combinations thereof, and wherein the modifying accomplishes at least one of changing surface properties of the porous materials; and

changing the three-dimensional surfaces.

22. The method as defined in claim 21, further comprising the step of crosslinking the gelatin coating layer.

23. The method as defined in claim 21 wherein the coating is accomplished by at least one of mechanical application;

thermal application;

adhering;

self-assembling;

molecular entrapment;

chemical bonding; and

combinations thereof.

24. Modified porous materials formed by the process of claim 21.