IP Library › Granted Patent US 8,569,395
Granted Patent B2
US 8,569,395 · App. 13/562,867 · Granted Oct 29, 2013

Methods for making oxidation-resistant cross-linked polymeric materials

Inventors: Orhun K. Muratoglu (Cambridge, MA); Edward T. Kopesky (Arlington, MA); Ebru Oral (Newton, MA)
Assignees: The General Hospital Corporation; Cambridge Polymer Group, Inc.
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Quick Facts
Patent No.
US 8,569,395
App. No.
13/562,867
Granted
Oct 29, 2013
Kind
B2
Abstract

The present invention relates to methods for making cross-linked oxidation-resistant polymeric materials and preventing or minimizing in vivo elution of antioxidant from the antioxidant-containing polymeric materials. The invention also provides methods of doping polymeric materials with a spatial control of cross-linking and antioxidant distribution, for example, vitamin E (α-Tocopherol), and methods for extraction/elution of antioxidants, for example, vitamin E (α-tocopherol), from surface regions of antioxidant-containing polymeric materials, and materials used therewith also are provided.

Claims (46)

1. A method of making an oxidation-resistant cross-linked polymeric material comprising:

a) blending a polymeric material with an antioxidant, wherein a first portion of the polymeric material is contacted with a concentration of an antioxidant and a second portion of the polymeric material is contacted with another concentration of the antioxidant;

b) consolidating the antioxidant blended polymeric material, thereby forming a medical implant preform; and

c) irradiating the medical implant preform containing the antioxidant blended polymeric material with ionizing radiation, thereby forming a medical implant preform having an oxidation-resistant cross-linked polymeric material.

2. The method according to claim 1 , wherein the polymeric material is polymeric resin powder, polymeric flakes, polymeric particles, or the like, or a mixture thereof.

3. The method according to claim 1 , wherein the blended polymeric material in the first or the second portion, in the surface or in the bulk of the polymeric material contains the same concentration of the antioxidant.

4. The method according to claim 1 , wherein the blended polymeric material in the first or the second portion, in the surface or in the bulk of the polymeric material contains different concentration of the antioxidant.

5. The method according to claim 4 , wherein the irradiated medical implant preform contains spatially distributed antioxidant and forms a medical implant preform having an oxidation-resistant cross-linked polymeric material having a spatially controlled cross-linking and antioxidant distribution.

6. The method according to claim 1 , wherein the irradiation is carried out at a temperature that is above the room temperature and below the melting point of the polymeric material, wherein the temperature is between about 40° C. and about 135° C.

7. A method of making an oxidation-resistant cross-linked polymeric material comprising:

a) blending a polymeric material with an antioxidant, wherein a first portion of the polymeric resin, flakes, or powder is contacted with a lower concentration of an antioxidant and a second portion of the polymeric resin, flakes, or powder is contacted with a higher concentration of the antioxidant than the first portion, thereby allowing a spatially controlled distribution of the antioxidant-rich and antioxidant-poor regions;

b) consolidating the antioxidant blended polymeric material, thereby forming a medical implant preform; and

c) irradiating the medical implant preform containing the spatially distributed antioxidant with ionizing radiation, thereby forming a medical implant preform having an oxidation-resistant cross-linked polymeric material having a spatially controlled cross-linking and antioxidant distribution.

8. The method according to claim 7 , wherein the blends of polymeric resin, flakes, or powder, the surface or the bulk of the polymeric blends contain the same concentration of antioxidant.

9. A method of making an oxidation-resistant cross-linked medical implant comprising the steps of:

a) blending one or more types of resin, flakes, or powder with an antioxidant, wherein a first portion of the resin, flakes, or powder are contacted with a concentration of an antioxidant and a second portion of the resin, flakes, or powder are contacted with another concentration of the antioxidant, thereby allowing a spatially controlled distribution of the antioxidant in the polymeric blends; and

b) consolidating the antioxidant-blended resins, flakes, or powders by layering, thereby forming a medical implant.

10. The method according to claim 9 , wherein the medical implant is irradiated, thereby forming an oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution.

11. The method according to claim 9 , wherein the blends of resin, flakes, or powder, in the first or second portion, or the surface or the bulk of the polymeric material contain the same concentration of antioxidant.

12. The method according to claim 9 , wherein the blends of resin, flakes, or powder, in the first or second portion, or the surface or the bulk of the polymeric material contain the different concentration of antioxidant.

13. The method according to claim 9 , wherein the antioxidant blended polymeric material is compression molded to another piece or a medical implant, thereby forming an interface or an interlocked hybrid material.

14. The method according to claim 13 , wherein the interlocked hybrid material is irradiated, thereby forming an oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution.

15. The method according to claim 13 , wherein the another piece onto which the resins, flakes or powders are consolidated is a metal.

16. The method according to claim 13 , wherein the another piece onto which the resins, flakes or powders are consolidated is porous.

17. The method according to claim 9 , wherein the oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution is machined.

18. The method according to claim 9 , wherein the oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution is packaged and sterilized.

19. The method according to claim 10 , wherein the irradiated medical implant is heated to below the peak melting point of the consolidated resins, flakes or powders.

20. The method according to claim 10 , wherein the irradiated medical implant is heated to above the peak melting point of the consolidated resins, flakes or powders.

21. The method according to claim 10 , wherein the oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution is machined.

22. The method according to claim 10 , wherein the oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution is packaged and sterilized.

23. The method according to claim 10 , wherein the irradiated medical implant is heated to above the peak melting point of the consolidated resins, flakes or powders.

24. A method of making an oxidation-resistant cross-linked polymeric material comprising:

a) blending a polymeric material with an antioxidant, wherein a first portion of the polymeric material is contacted with a concentration of an antioxidant and a second portion of the polymeric material is contacted with another concentration of the antioxidant;

b) compression molding the antioxidant blended polymeric material to another piece or a medical implant, thereby forming an interface or an interlocked hybrid material; and

c) irradiating the interlocked hybrid material containing the antioxidant with ionizing radiation, thereby forming a medical implant preform having an oxidation-resistant cross-linked polymeric material.

25. The method according to claim 24 , wherein the blended polymeric material in the first or the second portion, in the surface or in the bulk of the polymeric material contains the same concentration of the antioxidant.

26. The method according to claim 24 , wherein the blended polymeric material in the first or the second portion, in the surface or in the bulk of the polymeric material contains different concentration of the antioxidant.

27. The method according to claim 26 , wherein the irradiated medical implant preform contains spatially distributed antioxidant and forms a medical implant preform having an oxidation-resistant cross-linked polymeric material having a spatially controlled cross-linking and antioxidant distribution.

28. The method according to claim 24 , wherein the another piece onto which the resins, flakes or powders are consolidated is a porous metal.

29. The method according to claim 24 , wherein the irradiation is performed when the interlocked hybrid material is at a temperature above room temperature and below the melting point of the polymeric material, wherein the temperature is between about 40° C. and about 135° C.

30. The method according to claim 24 , wherein the oxidation-resistant medical implant preform is machined, thereby forming oxidation-resistant medical implant.

31. The method according to claim 30 , wherein the oxidation-resistant medical implant having a spatially controlled crosslinking and antioxidant distribution is packaged and sterilized.

32. The method according to claim 1 , wherein the antioxidant is vitamin E.

33. The method according to claim 7 , wherein the antioxidant is vitamin E.

34. The method according to claim 9 , wherein the antioxidant is vitamin E.

35. The method according to claim 24 , wherein the antioxidant is vitamin E.

Continuity (5)
Continuation 12522728
Provisional Application 60886527 · Jan 25, 2007
Provisional Application 60889037 · Feb 9, 2007
Provisional Application 60892346 · Mar 1, 2007
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