Medical devices having nanoporous coatings for controlled therapeutic agent delivery

• US 8,574,615 B2
• Filed: 05/25/2010
• Issued: 11/05/2013
• Est. Priority Date: 03/24/2006
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Tenney, Barron, Xu, Yixin, Helmus, Michael N.
• Primary Examiner(s): AZPURU, CARLOS A
• Application Number:
  US12/787,209
• Publication Number:
  US 20100233238A1
• Time in Patent Office: 1,260 Days
• Field of Search: None
• US Class Current: 424/423
• CPC Class Codes: A61F 2/02 Prostheses implantable into the body closure means for urethra or rectum or for artificial body openings therefor A61F2/0004
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• 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 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/3068 the pharmaceutical product being in a reservoir
• CPC Class Codes: A61F 2002/3084 Nanostructures
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: A61L 2300/00 Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
• CPC Class Codes: A61L 2400/12 Nanosized materials, e.g. nanofibres, nanoparticles, nanowires, nanotubes; Nanostructured surfaces
• CPC Class Codes: A61L 29/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61P 41/00 Drugs used in surgical methods, e.g. surgery adjuvants for preventing adhesion or for vitreum substitution
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites

Abstract

According to an aspect of the present invention, implantable or insertable medical devices are provided which contain (a) one or more depressions that contain at least one therapeutic agent, and (b) a nanoporous coating, disposed over the therapeutic-agent-containing depressions, which regulate transport of species between the therapeutic-agent-containing depressions and the exterior of the device. The implantable or insertable devices are configured to preform a role beyond mere drug delivery, for example, providing mechanical and/or electrical functions within the body, among other functions. An advantage of the present invention is that medical devices may be provided, which release therapeutic agents in quantities far exceeding the void volume within the nanoporous coating, while at the same time providing functionality that extends beyond drug delivery. Such release may further approach or achieve a zero order kinetic drug release profile.

Claims

1. An implantable or insertable medical device comprising:

a body having a first surface and a second surface;

a depression extending through the body, the depression having a first end defined in the first surface and a second end defined in the second surface;

a therapeutic agent within the depression;

a nanoporous layer on the first surface covering the first end of the depression; and

a non-nanoporous layer on the second surface covering the second end of the depression.

2. The implantable or insertable medical device of claim 1, wherein the smallest lateral dimension of the depression is less than 1000 μ

m.

3. The implantable or insertable medical device of claim 1, wherein the smallest lateral dimension of said depression is less than 100 μ

m.

4. The implantable or insertable medical device of claim 1, wherein the depression has an aspect ratio of greater than or equal to 1.

5. The implantable or insertable medical device of claim 4, wherein the aspect ratio of the depression is greater than or equal to 5 to 25 or more.

6. The implantable or insertable medical device of claim 1, wherein the body comprises a metal, a polymer, or a ceramic.

7. The implantable or insertable medical device of claim 1, wherein said the body comprises a silicon.

8. The implantable or insertable medical device of claim 1, wherein the nanoporous layer comprises a polymer, a metal, or a ceramic.

9. The implantable or insertable medical device of claim 8, wherein the ceramic comprises alumina, titania, and silica.

10. The implantable or insertable medical device of claim 1, wherein said nanoporous layer comprises a parallel pore structure.

11. The implantable or insertable medical device of claim 1, wherein said nanoporous layer comprises an interconnected pore structure.

12. The implantable or insertable medical device of claim 1, wherein said medical device is a stent and wherein said region comprising said depression is a stent strut.

13. The implantable or insertable medical device of claim 1, wherein the therapeutic agent is released from the depression through the nanoporous coating.

14. A method comprising:

forming a depression extending through a body, the body having a first surface and a second surface, and the depression having a first end defined in the first surface and a second end defined in the second surface;

forming a nanoporous layer on the body to cover the first end of the depression;

loading a therapeutic agent into the depression covered by the nanoporous layer; and

forming a non-nanoporous layer on the body to cover the second end of the depression.

15. The method of claim 14, wherein the depression is formed by molding.

16. The method of claim 14, wherein the depression is formed by direct- writing.

17. The method of claim 14, wherein the depression is formed using a mask.

18. The method of claim 14, wherein the nanoporous layer is formed by physical vapor deposition, chemical vapor deposition, self-assembly, a sol-gel process, or an electrochemical process.