Blood contacting medical device and method

• US 5,865,814 A
• Filed: 08/06/1997
• Issued: 02/02/1999
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Tuch, Ronald J.
• Primary Examiner(s): DUDASH, DIANA L
• Application Number:
  US08/906,927
• Time in Patent Office: 545 Days
• Field of Search: 623/1, 623/900, 623/12, 604/266, 604/265, 604/890.1, 604/97, 604/891.1, 424/424, 424/426, 606/194
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 33/0011 Anticoagulant, e.g. heparin, platelet aggregation inhibitor, fibrinolytic agent, other than enzymes, attached to the substrate
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10S 623/90 Stent for heart valve

Abstract

A a blood-contacting medical device with improved biocompatibility. The device is coated with a layer of water-soluble heparin, overlaid by a porous polymeric coating through which the heparin can elute. The inclusion of a porous polymer in intimate contact with a heparin on the device controls the administration of heparin following implantation or other blood contact. The adhesion of the coating and the rate at which the heparin is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer.

Claims

1. A medical device for use in contact with circulating blood comprising:

(a) a medical device having a blood-contacting surface;

(b) a first coating layer on the blood-contacting surface consisting essentially of water soluble heparin; and

(c) a second coating layer comprising a porous polymer overlaying the first coating layer such that heparin is elutable from the medical device through the second coating layer.

2. A device according to claim 1 wherein the blood-contacting surface has a metal surface.

3. A device according to claim 1 wherein the blood-contacting surface has a polymeric surface.

4. A device according to claim 1 wherein the polymer is a bioabsorbable polymer.

5. A device according to claim 4 wherein the polymer is selected from the group consisting of poly(lactic acid), poly(lactide-co-glycolide) and poly(hydroxybutyrate-co-valerate).

6. A device according to claim 1 wherein the polymer is a biostable polymer.

7. A device according to claim 6 wherein the polymer is selected from the group consisting of silicones, polyurethanes, polyesters, vinyl homopolymers and copolymers, acrylate homopolymers and copolymers, polyethers and cellulosics.

8. A device according to claim 1 wherein the device is a radially expandable intravascular stent.

9. A device according to claim 1 in which the porous polymer has average pore diameter in the range of about 0.5-10 microns.

10. A medical device for use in contact with circulating blood comprising:

(a) medical device having a blood-contacting surface;

(b) a first coating layer on the blood-contacting surface comprising a hydrophilic polymer;

(c) a second coating layer comprising water soluble heparin overlaying the first coating layer; and

(d) a third coating layer comprising a porous polymer overlaying the second coating layer such that heparin is elutable from the medical device through the third coating layer.

11. A device according to claim 10 wherein the blood-contacting surface has a metal surface.

12. A device according to claim 10 wherein the blood-contacting surface has a polymeric surface.

13. A device according to claim 10 wherein the porous polymer is a bioabsorbable polymer.

14. A device according to claim 13 wherein the bioabsorbable polymer is selected from the group consisting of poly(lactic acid), poly(lactide-co-glycolide) and poly(hydroxybutyrate-co-valerate).

15. A device according to claim 10 wherein the porous polymer is a biostable polymer.

16. A device according to claim 15 wherein the biostable polymer is selected from the group consisting of silicones, polyurethanes, polyesters, vinyl homopolymers and copolymers, acrylate homopolymers and copolymers, polyethers and cellulosics.

17. A device according to claim 10 wherein the device is a radially expandable intravascular stent.

18. A medical device for use in contact with circulating blood comprising:

(a) medical device having a blood-contacting surface;

(b) a first coating layer on the blood-contacting surface comprising a hydrophobic polymer;

(c) a second coating layer comprising water soluble heparin overlaying the first coating layer; and

(d) a third coating layer comprising a porous polymer overlaying the second coating layer such that heparin is elutable from the medical device through the third coating layer.

19. A device according to claim 18 wherein the second coating layer comprises beads of heparin, and wherein the third coating layer encapsulates the beads of heparin.

20. A device according to claim 18 wherein the blood-contacting surface has a metal surface.

21. A device according to claim 18 wherein the blood-contacting surface has a polymeric surface.

22. A device according to claim 18 wherein the porous polymer is a bioabsorbable polymer.

23. A device according to claim 22 wherein the bioabsorbable polymer is selected from the group consisting of poly(lactic acid), poly(lactide-co-glycolide) and poly(hydroxybutyrate-co-valerate).

24. A device according to claim 18 wherein the porous polymer is a biostable polymer.

25. A device according to claim 24 wherein the biostable polymer is selected from the group consisting of silicones, polyurethanes, polyesters, vinyl homopolymers and copolymers, acrylate homopolymers and copolymers, polyethers and cellulosics.

26. A device according to claim 18 wherein the device is a radially expandable intravascular stent.