Coronary stent with a radioactive, radiopaque coating

• US 5,919,126 A
• Filed: 08/18/1997
• Issued: 07/06/1999
• Est. Priority Date: 07/07/1997
• Status: Expired due to Fees

• Current Assignee: Implant Sciences Corporation
• Original Assignee: Implant Sciences Corporation
• Inventors: Armini, Anthony J.
• Primary Examiner(s): Lacyk, John P.
• Application Number:
  US08/912,762
• Time in Patent Office: 687 Days
• Field of Search: 600/1, 600/3, 606/108, 606/139, 606/191, 606/198, 606/194, 623/1, 623/12
• US Class Current: 600/3
• 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 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2210/0095 radioactive
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61K 51/1282 Devices used in vivo and carrying the radioactive therapeutic or diagnostic agent, therapeutic or in vivo diagnostic kits, stents
• CPC Class Codes: A61L 31/08 Materials for coatings
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: A61N 5/1002 Intraluminal radiation therapy
• CPC Class Codes: C23C 14/165 by cathodic sputtering
• CPC Class Codes: C23C 14/48 Ion implantation
• CPC Class Codes: H01J 2237/31701 Ion implantation

Abstract

A stent according to the systems and methods described herein may include a body formed from a non-radioactive structural material, a radiopaque material coating the body, and a beta-emitting radioisotope ion implanted into the radiopaque material. Optionally, an adhesion layer, such as titanium, vanadium, chromium, iron, cobalt, nickel, or some combination or alloy thereof, may be applied to the body to facilitate adhesion of the radiopaque material. The radiopaque material may include platinum, iridium, rhenium, gold, tantalum, or some combination or alloy thereof. The beta-emitting radioisotope may include sulfur-35 or phosphorous-32 and may be ion implanted into the radiopaque material.

Claims

1. A stent comprising:

a body comprising a non-radioactive structural material;

a radiopaque material disposed on said body;

an adhesion layer coupled to said body and said radiopaque material; and

a beta-emitting radioisotope ion implanted into said radiopaque material.

2. The stent according to claim 1, wherein said adhesion layer comprises at least one material selected from the group consisting of titanium, vanadium, chromium, iron, cobalt and nickel.

3. The stent according to claim 1, wherein said body comprises a longitudinal portion and a circumferential portion, and wherein said radiopaque material coats both of said portions with substantially even thickness.

4. The stent according to claim 1, wherein said beta-emitting radioisotope emits substantially no alpha or gamma radiation.

5. The stent according to claim 1, wherein said radiopaque material comprises at least one material selected from the group consisting of platinum, iridium, and rhenium.

6. The stent according to claim 1, wherein said radiopaque material comprises at least one material selected from the group consisting of gold and tantalum.

7. The stent according to claim 1, wherein said beta-emitting radioisotope comprises sulfur-35.

8. The stent according to claim 1, wherein said beta-emitting radioisotope comprises phosphorous-32.

9. The stent according to claim 1, wherein said radiopaque material is between approximately 1 micron and approximately 5 microns thick.

10. The stent according to claim 1, wherein said radiopaque material is between approximately 1 micron and approximately 15 microns thick.

11. The stent according to claim 1, wherein said beta-emitting radioisotope is ion implanted to a depth of less than approximately 3000 angstroms into said radiopaque material.

12. The stent according to claim 1, wherein said beta-emitting radioisotope is ion implanted with a source strength of between approximately 0.1 microcuries and 10 microcuries.

13. The stent according to claim 1, wherein said beta-emitting radioisotope has a half life of less than approximately 100 days.

14. The stent according to claim 1, wherein said body has a tubular mesh shape.

15. The stent according to claim 1, wherein said body comprises a helical coil.

16. The stent according to claim 1, wherein said adhesion layer comprises a transition metal.

17. The stent according to claim 1, wherein said adhesion layer is between approximately 100 angstroms and approximately 3000 angstroms thick.