Method of forming hollow tubular drug eluting medical devices

• US 8,916,226 B2
• Filed: 09/26/2013
• Issued: 12/23/2014
• Est. Priority Date: 09/20/2009
• Status: Expired due to Fees

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Mauch, Kevin, Ward, Sean, Jamous, Aram
• Primary Examiner(s): SELLMAN, CACHET I
• Application Number:
  US14/038,300
• Publication Number:
  US 20140091057A1
• Time in Patent Office: 453 Days
• Field of Search: 295/57, 623/1.15
• US Class Current: 427/2.1
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2220/0041 using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

A method of a forming a hollow, drug-eluting medical device includes utilizing a hollow wire having an outer member and a lumen of the outer member, and filling the lumen with a fluid to form a supported hollow wire. The supported hollow wire is shaped into a stent pattern. Openings are formed through the outer member. The supported hollow wire is processed to remove the fluid from the lumen of the outer member without adversely affecting the outer member, leaving the hollow wire shaped into a stent pattern. The lumen is filled with a biologically or pharmacologically active substance.

Claims

1. A method of forming a stent with hollow struts comprising the steps of:

stacking a first sheet of a first material, a second sheet of a second material, and a third sheet of third material disposed between the first sheet and the second sheet to form a stacked laminate of materials;

stamping a flat stent pattern from the stacked laminate of materials, wherein the stamping step removes the first, second, and third materials from portions of the stacked laminate of materials, thereby leaving the flat stent pattern with a cross-section having the first material, the second material, and the third material, wherein the stamping step pushes the third sheet inward and edges of the first sheet and the second sheet together to surround the third sheet such that a cross-section through struts of the flat stent pattern includes the first material and the second material completely surrounding the third material;

after the stamping step, processing the stent pattern to remove the third material from within the first material and the second material such that a cross-section of the struts includes the first material and the second material surrounding a lumen;

rolling the flat stent pattern such that longitudinal edges of the flat stent pattern abut against each other to form a tube, and bonding the longitudinal edges to each other; and

filling the lumen with a biologically or pharmacologically active substance.

2. The method of claim 1, further comprising the step of forming openings through the first material or the second material from an outer surface of the first material or the second material through an inner surface of the first material or the second material.

3. The method of claim 2, wherein the step of forming openings is performed prior to removing the third material from within the first material and the second material.

4. The method of claim 2, wherein the step of forming openings is performed after removing the third material from within the first material and the second material.

5. The method of claim 1, wherein the step of rolling the flat stent pattern is performed after the step of processing the stent pattern to remove the third material.

6. The method of claim 1, wherein the step of rolling the flat stent pattern is performed before the step of processing the stent pattern to remove the third material.

7. The method of claim 1, wherein the first material and the second material are the same material.

8. The method of claim 7, wherein the first material and the second material are MP35N.

9. The method of claim 1, wherein the step of removing the third material comprises exposing the stent pattern to an etchant that removes the third material and does not adversely affect the first material and the second material.

10. The method of claim 9, wherein the etchant is xenon difluoride gas.

11. The method of claim 9, wherein the first material and the second material are both MP35N, the third material is tantalum, and the etchant is xenon difluoride gas.

12. The method of claim 1, wherein the step of processing the stent pattern to remove the third material is selected from the group consisting of chemical etching, wet chemical dissolution, solubilization, sublimation, and melting.

13. The method of claim 1, wherein the biologically or pharmacologically active substance is selected from the group consisting of glucocorticoids, antithrombotic agents, growth factors, antisense agents, anti-cancer agents, anti-proliferative agents, oligonucleotides, antibiotics, antiplatelet agents, anti-coagulant agents, antimitotic agents, antioxidants, antimetabolite agents, and anti-inflammatory agents.