Polymer composite stent with polymer particles

• US 9,072,820 B2
• Filed: 06/26/2006
• Issued: 07/07/2015
• Est. Priority Date: 06/26/2006
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Gale, David C., Wang, Yunbing
• Primary Examiner(s): Richter, Johann R
• Assistant Examiner(s): Peebles, Katherine
• Application Number:
  US11/475,434
• Publication Number:
  US 20070299504A1
• Time in Patent Office: 3,298 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: A61L 31/129 containing macromolecular fillers

Abstract

Polymer composite implantable medical devices, such as stents, and methods of manufacturing such devices are disclosed.

Claims

1. An implantable medical device comprising a structural element, the structural element including a composite, the composite having a plurality of polymer nanoparticles dispersed within a polymer matrix, wherein each of the polymer nanoparticles is a discrete, single phase within the polymer matrix, wherein the polymer nanoparticles have a lower modulus than the matrix polymer, and wherein the composite comprises a higher toughness than the matrix polymer, wherein the polymer nanoparticles are biodegradable, wherein the polymer matrix is poly(L-lactide) and the nanoparticles comprise less than 5 wt % of the composite.

2. The device of claim 1, wherein the polymer nano-particles comprise a cross-linked polymer.

3. The device of claim 1, wherein the polymer nano-particles increase the toughness of the matrix polymer.

4. The device of claim 1, wherein the polymer nano-particles have a higher degradation rate than the matrix polymer.

5. The device of claim 1, wherein the polymer nano-particles are uniformly dispersed within the polymer matrix.

6. The device of claim 1, wherein the degradation products of the polymer nanoparticles are acidic, the acidic degradation products being capable of increasing the degradation rate of the matrix polymer.

7. The device of claim 1, wherein the polymer nano-particles are immiscible with the matrix polymer.

8. The device of claim 1, wherein the polymer nano-particles comprise a non-crosslinked polymer.

9. The device of claim 1, wherein matrix polymer crystalline domains are formed adjacent to or around the polymer nanoparticles, the crystalline domains being dispersed throughout an amorphous domain of the matrix polymer in the composite, the crystalline domains increase the strength and modulus of the composite.

10. The device of claim 1, wherein the polymer nanoparticles are selected from the group consisting of poly(lactide-co-trimethylene carbonate), poly(glycolide-co-trimethylene carbonate), poly(glycolic acid-co-trimethylene carbonate)-block-polylactide, poly(lactide-co-ε

-caprolactone), poly(glycolide-co-caprolactone), and poly(hydroxybutyrate-co-caprolactone).

11. The device of claim 1, wherein the polymer nanoparticles have a half-life selected from the group consisting of 10%, 30%, 50%, 70%, and 90% of the matrix polymer.

12. The device of claim 1, wherein the polymer nanoparticles are less than 100 nm in length if fibrous or less than 100 nm in diameter if spherical.

13. The device of claim 1, wherein the polymer nanoparticles are less than 1000 nm in length if fibrous or less that 1000 nm in diameter of spherical.

14. The device of claim 1, wherein the composite is less than 1 wt % nanoparticles as compared to the matrix polymer.

15. The device of claim 1, wherein the composite is less than 5 wt % nanoparticles as compared to the matrix polymer.

16. An implantable medical device comprising a structural element, the structural element including a composite, the composite having a plurality of polymer nanoparticles dispersed within a polymer matrix, wherein each of the polymer nanoparticles is a discrete, single phase within the polymer matrix, wherein the polymer nanoparticles have a lower modulus than the matrix polymer, and wherein the composite comprises a higher toughness than the matrix polymer, wherein the polymer nanoparticles are biodegradable, wherein the polymer matrix is poly(L-lactide), the device is a stent and the nanoparticles comprise less than 5 wt % of the composite.

17. The device of claim 16, wherein the polymer nanoparticles have a higher degradation rate or lower half-life than the matrix polymer.

18. The device of claim 16, wherein the composite is less than 5 wt % polymer nanoparticles as compared to the matrix polymer.

19. The device of claim 16, wherein the polymer nanoparticles are less than 1000 nm in length if fibrous or less than 1000 nm in diameter if spherical.

20. The device of claim 16, wherein the polymer nanoparticles comprise an elastomeric polymer.