IMPLANTABLE MEDICAL DEVICES HAVING MICROPOROUS SURFACE LAYERS AND METHOD FOR REDUCING FOREIGN BODY RESPONSE TO THE SAME

• US 20110257623A1
• Filed: 04/08/2011
• Published: 10/20/2011
• Est. Priority Date: 11/25/2009
• Status: Active Grant

• Current Assignee: Healionics Corporation
• Original Assignee: Healionics Corporation
• Inventors: Alvarez, Michel, Marshall, Andrew J., Maginness, Max
• Granted Patent: US 8,372,423 B2
• Time in Patent Office: Days
• US Class Current: 604/500
• 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: 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 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 29/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61P 31/00 Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: Y10T 428/12479 Porous [e.g., foamed, spongy, cracked, etc.]
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/249979 Specified thickness of void-containing component [absolute or relative] or numerical cell dimension

Abstract

This disclosure provides implantable devices coated with microporous surface layers with macrotopographic features that improve bio-integration at the interface of the implantable devices and the surrounding tissue.

Claims

1. A microporous biomaterial with macrotopographic surface features and a plurality of pores, wherein substantially all the pores are each interconnected to at least 2 other pores, a mean diameter of the pores is between about 5 and about 100 micrometers, and any two adjacent pores are connected by a throat, a mean throat diameter of the throats being between about 5 micrometers and about 50 micrometers, and wherein the macrotopography is defined by a plurality of peaks and valleys, wherein each peak is porous and has a height of between about 100 micrometers and about 2000 micrometers, and at least two adjacent peaks define a valley, the valley having a floor from which the heights of the adjacent peaks are measured.

2. The microporous biomaterial of claim 1, comprising an open-cell structure throughout the entire microporous biomaterial.

3. The microporous biomaterial of claim 1, wherein the surface of the floor of the valleys between the peaks is impermeable to fluids.

4. The microporous biomaterial of claim 1, wherein the surface of the floor of the valleys between the peaks is microporous.

5. The microporous biomaterial of claim 1, wherein the biomaterial is permeable to fluids or electrolytes.

6. The microporous biomaterial of claim 1, wherein the mean pore diameter is between about 20 and about 40 micrometers.

7. The microporous biomaterial of claim 1, wherein the height of each peak is between about 100 micrometers and about 500 micrometers.

8. The microporous biomaterial of claim 1, wherein the height of each peak is between about 200 micrometers and about 1000 micrometers.

9. The microporous biomaterial of claim 1, wherein the height of each peak is between about 500 micrometers and about 2000 micrometers.

10. The microporous biomaterial of claim 1, wherein the height of each peak is between about 500 micrometers and about 1000 micrometers.

11. The microporous biomaterial of claim 1, wherein the biomaterial is biodegradable.

12. The microporous biomaterial of claim 1, wherein the biomaterial is a hydrogel, silicone rubber, expanded fluoropolymer, a polymer or a metal.

13. The microporous biomaterial of claim 1, wherein the biomaterial comprises a conductive polymer or metalized polymer.

14. The biomaterial of claim 1, wherein the biomaterial has a thickness of at least 40 micrometers excluding the height of the peaks.

37. A method comprising:

implanting the microporous biomaterial of claim 1.

38. The method of claim 37, wherein the microporous biomaterial is a surface layer overlying an implantable device.

40. A method for reducing risk of device-related infection comprising:

implanting an implantable device comprising;

a device body; and

the microporous biomaterial of claim 1.

42. A method for promoting angiogenesis comprising:

implanting an implantable device comprising;

a device body; and

the microporous biomaterial of claim 1.

15. An implantable device comprising:

a device body; and

a microporous biomaterial overlying the device body wherein the microporous biomaterial has macrotopographic surface features and a plurality of pores, and wherein substantially all the pores are each interconnected to at least 2 other pores, a mean diameter of the pores is between about 5 and about 100 micrometers, and any two adjacent pores are connected by a throat, a mean throat diameter of the throats being between about 5 micrometers and about 50 micrometers, and wherein the macrotopography is defined by a plurality of peaks and valleys, wherein each peak is porous and has a height of between about 100 micrometers and about 2000 micrometers, and at least two adjacent peaks define a valley, the valley having a floor from which the heights of the adjacent peaks are measured.

16. The implantable device of claim 15, further comprising an intermediate layer interposed between the device body and the microporous surface layer.

44. The implantable device of claim 16, wherein the intermediate layer is a conformal sheath that covers a part of or an entire native surface of the device body

17. The implantable device of claim 16, wherein the intermediate layer is an adhesive layer.

17-1. (canceled)

18. An implantable device comprising:

a device body; and

a textured surface layer overlying the device body, wherein the textured surface layer comprises one or more granules of a microporous biomaterial, the granules forming a surface macrotopography that includes a plurality of peaks and valleys, each peak having a height of between about 100 micrometers and about 2000 micrometers, and wherein each granule comprises a plurality of interconnecting pores having a mean pore diameter of between about 5 and 100 micrometers, and any two adjacent pores are connected by a throat, a mean throat diameter of the throats being between 5 and 50 micrometers, and at least two adjacent peaks define a valley, the valley having a floor from which the heights of the adjacent peaks are measured.

19. The implantable device of claim 18 wherein the mean pore diameter is between about 20 and about 40 micrometers.

20. The implantable device of claim 18, wherein the height of each peak is between about 200 micrometers and about 1000 micrometers.

21. The implantable device of claim 18, wherein the height of each peak is between about 500 micrometers and about 2000 micrometers.

22. The implantable device of claim 18, wherein the height of each peak is between about 500 micrometers and about 1000 micrometers.

23. The implantable device of claim 18, further comprising an intermediate layer interposed between the device body and the textured surface layer.

24. The implantable device of claim 23, wherein the intermediate layer is an adhesive layer.

25. The implantable device of claim 23, wherein the intermediate layer is a conformal sheath that covers a part of or an entire native surface of the device body.

26. The implantable device of claim 22, wherein the textured surface layer covers more than 80%, or more than 90% of a total area of a native surface of the device body.

27. The implantable device of claim 18, wherein the surface of the floor of the valleys between the peaks is impermeable to fluids.

41. A method for reducing risk of device-related infection comprising:

implanting the implantable device of claim 18.

43. A method for promoting angiogenesis comprising:

implanting the implantable device of claim 18.

28. A method for forming a microporous biomaterial with macrotopographic features:

(a) arranging macro-porogens to form the template for a dissolvable mold surface with macrotopographic mold features, wherein the macro-porogens have a mean macro-porogen diameter that is between about 100 and about 2000 micrometers;

(b) removing the macro-porogens from the mold surface of (a) by chemical dissolution;

(c) filling the macrotopographic mold features with micro-porogens such that points of contact and interstitial spaces between adjacent micro-porogens are formed, wherein the micro-porogens have a mean micro-porogen diameter that is between about 5 micrometers and about 100 micrometers;

(d) fusing the micro-porogens together and to the surface of the mold at the points of contact;

(e) introducing a liquid biocompatible polymer precursor into the interstitial space between the micro-porogens;

(f) solidifying the biocompatible polymer precursor; and

(g) removing the micro-porogens and the dissolvable mold surface.

29. The method of claim 28, wherein the macro-porogens comprise salt crystals.

30. The method of claim 28, wherein the macro-porogens comprise thermoplastic beads.

31. The method of claim 28, wherein the macro-porogens comprise poly(methyl methacrylate) or polystyrene beads.

32. The method of claim 28, wherein the micro-porogens comprise salt crystals.

33. The method of claim 28, wherein the micro-porogens comprise thermoplastic beads.

34. The method of claim 28, wherein the micro-porogens comprise poly(methyl methacrylate) or polystyrene beads.

35. The method of claim 28, wherein the biomaterial is silicone rubber or hydrogel.

36. The method of claim 28, wherein the dissolvable mold surface is poly(methyl methacrylate) or polystyrene.

39. A method for reducing the foreign body response comprising:

implanting an implantable device comprising;

a device body; and

a microporous biomaterial or an implantable device, wherein the microporous biomaterial has macrotopographic surface features and a plurality of pores, and wherein substantially all the pores are each interconnected to at least 2 other pores, a mean diameter of the pores is between about 5 and about 100 micrometers, and any two adjacent pores are connected by a throat, a mean throat diameter of the throats being between about 5 micrometers and about 50 micrometers, and wherein the macrotopography is defined by a plurality of peaks and valleys wherein each peak is porous and has a height of between about 100 micrometers and about 2000 micrometers, and at least two adjacent peaks define a valley, the valley having a floor from which the heights of the adjacent peaks are measured; and

wherein the implantable device comprises a device body; and

a textured surface layer overlying the device body, wherein the textured surface layer comprises one or more granules of a microporous biomaterial, the granules forming a surface macrotopography that includes a plurality of peaks and valleys, each peak having a height of between about 100 micrometers and about 2000 micrometers, and wherein each granule comprises a plurality of interconnecting pores having a mean pore diameter of between about 5 and 100 micrometers, and any two adjacent pores are connected by a throat, a mean throat diameter of the throats being between 5 and 50 micrometers, and at least two adjacent peaks define a valley, the valley having a floor from which the heights of the adjacent peaks are measured.