Implantable device with reservoirs for increased drug loading

• US 7,575,593 B2
• Filed: 01/30/2007
• Issued: 08/18/2009
• Est. Priority Date: 01/30/2007
• Status: Expired due to Fees

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Allen, Jeff, Rea, Susan
• Primary Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US11/668,907
• Publication Number:
  US 20080183281A1
• Time in Patent Office: 931 Days
• Field of Search: 623 111- 148, 623/901
• US Class Current: 623/1.42
• 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 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: A61L 2300/61 containing two or more active agents in different layers
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• 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: A61P 7/02 Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: A61P 9/10 for treating ischaemic or atherosclerotic diseases, e.g. antianginal drugs, coronary vasodilators, drugs for myocardial infarction, retinopathy, cerebrovascula insufficiency, renal arteriosclerosis
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device

Abstract

A method of manufacturing a drug loaded stent includes applying a photo resistant coating to at least a portion of a stent framework and removing at least a portion of the photo resistant coating from the stent framework. The method further includes applying an etchant to at least a portion of the stent framework and forming a plurality undercut drug reservoirs in the stent framework based on applying the etchant. A stent for treating a vascular condition includes a stent framework, a plurality of undercut reservoirs formed within the stent framework and a therapeutic agent disposed within at least a portion of the plurality of undercut reservoirs.

Claims

1. A method of manufacturing a drug loaded stent, the method comprising:

applying a photo resistant coating to at least a portion of a stent framework;

removing at least a portion of the photo resistant coating from the stent framework,

applying an etchant to at least a portion of the stent framework; and

forming a plurality undercut drug reservoirs in the stent framework based on the etchant application,

wherein a first portion of the stent framework includes at least one drug reservoir comprising a pore and a second portion of the stent framework includes at least one drug reservoir comprising an elongated channel, the elongated channel spaced apart from the at least one pore.

2. The method of claim 1 wherein the drug reservoir includes a first width at a surface of the stent framework and a second width recessed from the surface of the stent framework, the first width being narrower than the second width.

3. The method of claim 1 further comprising:

loading at least one of the undercut drug reservoirs with a first therapeutic agent.

4. The method of claim 3 wherein the first therapeutic agent is the same as the second therapeutic agent.

5. The method of claim 3 wherein the first therapeutic agent comprises a drug selected from the group consisting of antiangiogenesis agents, antiendothelin agents, antimitogenic factors, antioxidants, antiplatelet agents, antiproliferative agents, antisense oligonucleotides, antithrombogenic agents, calcium channel blockers, clot dissolving enzymes, growth factors, growth factor inhibitors, nitrates, nitric oxide releasing agents, vasodilators, virus-mediated gene transfer agents.

6. The method of claim 3 further comprising:

coating at least a portion of the stent framework with a second therapeutic agent.

7. The method of claim 3 wherein the first therapeutic agent is different than the second therapeutic agent.

8. The method of claim 6 wherein the second therapeutic agent comprises a drug selected from the group consisting of antiangiogenesis agents, antiendothelin agents, antimitogenic factors, antioxidants, antiplatelet agents, antiproliferative agents, antisense oligonucleotides, antithrombogenic agents, calcium channel blockers, clot dissolving enzymes, growth factors, growth factor inhibitors, nitrates, nitric oxide releasing agents, vasodilators, virus-mediated gene transfer agents.

9. A system for treating a vascular condition, comprising:

a catheter;

a stent disposed on the catheter, the stent including a stent framework including a plurality of undercut reservoirs formed therein, wherein a first portion of the stent framework includes at least one drug reservoir comprising a pore and a second portion of the stent framework includes at least one drug reservoir comprising an elongated channel, the elongated channel spaced apart from the at least one pore; and

at least one therapeutic agent loaded within the reservoirs.

10. The system of claim 9 wherein the undercut reservoirs include an undercut portion of the stent framework surface, the undercut portion defined by a perimeter of the reservoir opening and an outer wall of the chamber.

11. The system of claim 10 wherein the reservoir opening has a first width and the chamber has a second width, the first width less than the second width.

12. The system of claim 11 wherein the second width is at least twice the first width.

13. The system of claim 9 wherein the therapeutic agent loaded within the undercut drug reservoirs comprises a drug selected from the group consisting of antiangiogenesis agents, antiendothelin agents, antimitogenic factors, antioxidants, antiplatelet agents, antiproliferative agents, antisense oligonucleotides, antithrombogenic agents, calcium channel blockers, clot dissolving enzymes, growth factors, growth factor inhibitors, nitrates, nitric oxide releasing agents, vasodilators, virus-mediated gene transfer agents.

14. A stent for treating a vascular condition, the stent comprising

a stent framework;

a plurality of undercut reservoirs formed within the stent framework, wherein a first portion of the stent framework includes at least one drug reservoir comprising a pore and a second portion of the stent framework includes at least one drug reservoir comprising an elongated channel, the elongated channel spaced apart from the at least one pore; and

a therapeutic agent disposed within at least a portion of the plurality of undercut reservoirs.

15. The stent of claim 14 further comprising:

a therapeutic coating disposed on at least a portion of the stent framework.

16. The stent of claim 15 wherein the reservoir opening has a first width and the reservoir chamber has a second width, and wherein the first width is less than the second width.

17. The stent of claim 14 wherein the undercut reservoirs include an undercut portion of the stent framework surface, the undercut portion defined by a perimeter of the reservoir opening and an outer wall of a reservoir chamber.