Medical device employing liquid crystal block copolymers and method of making the same

• US 20070191813A1
• Filed: 02/14/2006
• Published: 08/16/2007
• Est. Priority Date: 02/14/2006
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Chen, John
• Granted Patent: US 7,662,129 B2
• Time in Patent Office: Days
• US Class Current: 604/524
• CPC Class Codes: A61L 29/049 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 29/126 having a macromolecular matrix
• CPC Class Codes: A61M 25/1027 Making of balloon catheters
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C09K 19/00 Liquid crystal materials
• CPC Class Codes: C09K 19/3809 Polyesters; Polyester derivatives, e.g. polyamides
• CPC Class Codes: C09K 19/3852 Poly(meth)acrylate derivatives
• CPC Class Codes: C09K 19/408 Polysiloxanes
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]

Abstract

A medical device, at least a portion of which is formed from a polymer composition including at least one liquid crystal block copolymer having at least one A block and at least one B block wherein the A block is formed of mesogenic repeat units and the B block is a soft block.

Claims

1. A medical device, at least a portion of said device formed from a polymer composition comprising at least one liquid crystal block copolymer having at least one A block and at least one B block and wherein

the A block comprises mesogenic repeat units;

and

the B block is a soft block.

2. The medical device of claim 1 wherein the liquid crystal block copolymer is selected from the group consisting of those polymers having the general formula A-B diblock, (A-B)_n wherein n is 3 to 20, A-B-A triblock, B-A-B triblock, B-(A-B)_n-B wherein n is 3 to 20, B-(A-B-C)_n-B wherein n is 3 to 20, A-B-A-B-A pentablock, A-B-C triblock wherein said at least one liquid crystal block copolymer further comprises at least one C block, A-C-B triblock wherein the liquid crystal block copolymer further comprises at least one C block, A-B-C random block and multiblock copolymer.

3. The medical device of claim 1 wherein said A block comprises at least one aromatic group per repeat unit of said A block.

4. The medical device of claim 1 wherein said A block comprises at least two aromatic groups per repeat unit of said A block.

5. The medical device of claim 1 wherein said B block is aliphatic.

6. The medical device of claim 1 wherein said B block is derived from a repeating unit selected from the group consisting of olefins, esters, ethers, amides and siloxanes.

7. The medical device of claim 1 wherein said B block is hydrophilic.

8. The medical device of claim 1 wherein said A block comprises about 2 to about 25 repeat units and said B block comprises about 2 to about 25 repeat units.

9. The medical device of claim 8 wherein said B block comprises about 2 to about 10 repeat units.

10. The medical device of claim 1 wherein said A block comprises

11. The medical device of claim 1 wherein the polymer composition further comprises at least one polymer selected from the group consisting of polyamides, polyesters, polyethers, polyolefins, polyimides, block copolymers comprising at least one polyolefin, polyester, polyether, polyamide, and/or polyimide segment, silicones, and mixtures thereof and mixtures thereof.

12. The medical device of claim 1 wherein the B block is formed from an amide repeat unit and the polymer composition further comprises at least one polyether-polyamide block copolymer.

13. The medical device of claim 1 wherein said liquid crystal block copolymer comprises about 50% to about 95% by weight of said A block and about 5% to about 50% by weight of said B block.

14. The medical device of claim 1 wherein said medical device is a catheter assembly comprising at least one shaft or shaft assembly, and said at least a portion of said medical device formed from said polymer composition is said at least one shaft or shaft assembly.

15. The medical device of claim 1 wherein the medical device is an inflatable medical balloon.

16. The medical device of claim 15 wherein said balloon is mounted on a catheter.

17. The medical device of claim 15 further in combination with a stent.

18. The medical device of claim 1 wherein said block copolymer further includes a C block, the C block comprises mesogenic repeat units, the mesogenic repeat units are different than those of the A block.

19. A medical device, at least a portion of said device formed from a polymer composition, the polymer composition comprising:

at least one liquid crystal block copolymer having at least one A block and at least one B block wherein the A block is formed of mesogenic repeat units and the B block is a soft block; and

at least one polymer which is compatible with said B block of said liquid crystal block copolymer.

20. The medical device of claim 19 wherein the liquid crystal block copolymer is selected from the group consisting of those polymers having the general formula A-B diblock, (A-B)_n wherein n is 3 to 20, A-B-A triblock, B-A-B triblock, B-(A-B)_n-B wherein n is 3 to 20, B-(A-B-C)_n-B wherein n is 3 to 20, A-B-A-B-A pentablock, A-B-C triblock wherein said at least one liquid crystal block copolymer further comprises at least one C block, A-C-B triblock wherein the liquid crystal block copolymer further comprises at least one C block, A-B-C random block and multiblock copolymer.

21. The medical device of claim 19 wherein said A block of said liquid crystal block copolymer formed of mesogenic repeat units comprising at least one aromatic group per unit.

22. The medical device of claim 19 wherein said A block of said liquid crystal block copolymer is formed of mesogenic repeat units comprising at least two aromatic groups per unit.

23. The medical device of claim 19 wherein said B block is aliphatic.

24. The medical device of claim 19 wherein said B block is derived from repeating units selected from the group consisting of olefins, esters, ethers, amides and siloxanes.

25. The medical device of claim 19 wherein said at least one polymer is selected from the group consisting of polyolefins, polyesters, polyethers, polyamides, polyimides, block copolymers comprising at least one polyolefin, polyester, polyether, polyamide, and/or polyimide segment, silicones, and mixtures thereof.

26. The medical device of claim 19 wherein said B block is derived from amide repeating units and said polymer is a poly(ether-block-amide).

27. The medical device of claim 19 wherein said device is a catheter assembly.

28. The medical device of claim 27 wherein said at least a portion of said medical device is a balloon mounted on said catheter assembly.

29. A medical device formed of a polymer composition comprising a blend of a thermoplastic base polymer comprising at least one segment of polyolefin, polyamide, polyester, polyether, or silicone wherein the polymer composition further comprises a liquid crystal block copolymer, the liquid crystal block copolymer comprises at least one A block and at least one B block, the structure of the B block being selected for compatibility with the at least one segment of polyolefin, polyamide, polyester, polyether or silicone of said thermoplastic base polymer.

30. A medical device as in claim 29 wherein the B block of the liquid crystal block copolymer and the at least one segment of polyamide, polyester, polyether or silicone in the thermoplastic base polymer are both substantially entirely aliphatic moieties.

31. A medical device as in claim 29 wherein, if said at least one segment of polyamide, polyester, or polyether in the thermoplastic base polymer is:

polyamide, then the B block the liquid crystal block copolymer is a polyamide segment,

polyester, then the B block is a polyester segment,

polyether, then the B block is a polyether segment.

32. A medical device as in claim 29 wherein the B block of the liquid crystal block copolymer is formed of the same repeating units as said at least one segment of polyamide, polyester, or polyether in the thermoplastic base polymer.

33. A medical device as in claim 29 wherein the thermoplastic base polymer is a member of the group consisting of polyolefins, polyesters, polyethers, polyamides, polyimides, block copolymers comprising at least one polyolefin, polyester, polyether, polyamide, and/or polyimide segment, silicones, and mixtures thereof.

34. A liquid crystal block copolymer which is reaction product of:

an A block which is a liquid crystal polymeric unit; and

a B block which is formed from repeating units of amide, ether, olefin or siloxane.

35. The liquid crystal block copolymer of claim 34 further in combination with a non-liquid crystal polymer, the B block of the liquid crystal block copolymer selected for compatibility with the non-liquid crystal polymer.