Stent with polymeric coating

• US 20040034409A1
• Filed: 08/11/2003
• Published: 02/19/2004
• Est. Priority Date: 08/13/2002
• Status: Abandoned Application

• Current Assignee: Biotronik Mess-Und Therapiegeraete GmbH & Company Ingenieurbuero Berlin (Biotronik SE & Company KG)
• Original Assignee: Biotronik Mess und Therapiegeraete GmbH and Co (Biotronik SE & Company KG)
• Inventors: Heublein, Bernd, Sternberg, Katrin, Tittelbach, Michael
• Application Number:
  US10/639,225
• Publication Number:
  US 20040034409A1
• Time in Patent Office: Days
• US Class Current: 623/1.46
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence

Abstract

The invention concerns an implantable stent (10) with an at least portion-wise polymeric coating (16). The coating material is admittedly intended to bond to known materials but by virtue of its properties it is intended to enjoy improved compatibility and reduce inflammatory and proliferative processes which can lead to restenosis. That is achieved in that the polymeric coating (16) in the implantable condition after production and sterilization contains poly-L-lactide of a mean molecular weight of more than 200 kDa.

Claims

1. A stent comprising:

an at least portion-wise polymeric coating, as measured in the implantable state after production and sterilization, of poly-L-lactide of a mean molecular weight of more than 200 kDa.

2. The stent of claim 1, wherein:

the mean molecular weight of the poly-L-lactide is more than 350 kDa.

3. The stent of claim 2, wherein:

a layer thickness of the polymeric coating is between 3 and 30 μ

m.

4. The stent of claim 3, wherein:

the layer thickness of the polymeric coating is between 8 and 15 μ

m.

5. The stent of claim 4, wherein:

the polymeric coating is on a base body of the stent that comprises at least one metal.

6. The stent of claim 4, wherein:

the polymeric coating is on a base body of the stent that comprises at least one metal alloy.

7. The stent of claim 6, wherein:

the metal alloy is at least partially biodegradable.

8. The stent of claim 7, wherein:

the biodegradable metal alloy is a magnesium alloy.

9. The stent of claim 5, wherein:

a passive coating containing amorphous silicon carbide is provided between the polymeric coating and the base body.

10. The stent of claim 9, wherein:

a spacer binds the polymeric coating to the passive coating.

11. The stent of claim 9, wherein:

a bonding layer binds the polymeric coating to the passive coating.

12. The stent of claim 11, wherein:

at least one pharmacologically active substance is contained in the polymeric coating.

13. The stent of claim 12, wherein:

the stent is adapted to maximize a contact surface with a vessel wall in which the stent would be placed.

14. The stent of claim 13, wherein:

the stent is adapted so that mechanical loading on the stent uniformly distributes the applied forces over all structural elements of the stent.

20. The stent of claim 1, wherein:

a layer thickness of the polymeric coating is between 3 and 30 μ

m.

21. The stent of claim 20, wherein:

the layer thickness of the polymeric coating is between 8 and 15 μ

m.

22. The stent of claim 1, wherein:

the polymeric coating is on a base body of the stent that comprises at least one metal.

23. The stent of claim 1, wherein:

the polymeric coating is on a base body of the stent that comprises at least one metal alloy.

24. The stent of claim 5, wherein:

the metal is at least partially biodegradable.

25. The stent of claim 5, wherein:

the metal alloy is at least partially biodegradable.

26. The stent of claim 5, wherein:

the metal is at least partially biodegradable.

27. The stent of claim 25, wherein:

the biodegradable metal alloy is a magnesium alloy.

28. The stent of claim 22, wherein:

a passive coating containing amorphous silicon carbide is provided between the polymeric coating and the base body.

29. The stent of claim 6, wherein:

a passive coating containing amorphous silicon carbide is provided between the polymeric coating and the base body.

30. The stent of claim 23, wherein:

a passive coating containing amorphous silicon carbide is provided between the polymeric coating and the base body.

31. The stent of claim 28, wherein:

a spacer binds the polymeric coating to the passive coating.

32. The stent of claim 29, wherein:

a spacer binds the polymeric coating to the passive coating.

33. The stent of claim 30, wherein:

a spacer binds the polymeric coating to the passive coating.

34. The stent of claim 28, wherein:

a bonding layer binds the polymeric coating to the passive coating.

35. The stent of claim 29, wherein:

a bonding layer binds the polymeric coating to the passive coating.

36. The stent of claim 30, wherein:

a bonding layer binds the polymeric coating to the passive coating.

37. The stent of claim 1, wherein:

at least one pharmacologically active substance is contained in the polymeric coating.

38. The stent of claim 1, wherein:

the stent is adapted to maximize a contact surface with a vessel wall in which the stent would be placed.

39. The stent of claim 1, wherein:

the stent is adapted so that a mechanical loading on the stent uniformly distributes the applied forces over all structural elements of the stent.

15. A process for producing an implantable stent with a polymeric coating of high-molecular poly-L-lactide, comprising the steps of:

(a) wetting the stent at least portion-wise with a fine mist of a solution of poly-L-lactide of a mean molecular weight of more than 650 kDa;

(b) drying the solution applied to the stent by blowing; and

(c) sterilizing the stent with electron beam sterilization.

16. The process of claim 15, wherein:

the process steps of wetting and drying are repeated until the polymeric coating is of a layer thickness of between 3 and 30 μ

m.

17. The process of claim 16, wherein:

the electron beam sterilization is implemented with a dosage in the range of between 15 and 35 kGy.

18. The process of claim 17, wherein:

the dosage is in the range of between 22 and 28 kGy.

19. The process of claim 16, wherein:

the electron beam sterilization is conducted with a predetermined electron kinetic energy in the range of between 4 and 5 MeV.

40. The process of claim 15, wherein:

the electron beam sterilization is implemented with a dosage in the range of between 15 and 35 kGy.

41. The process of claim 40, wherein:

the dosage is in the range of between 22 and 28 kGy.

42. The process of claim 15, wherein:

the electron beam sterilization is conducted with a predetermined electron kinetic energy in the range of between 4 and 5 MeV.