Medicated porous metal prosthesis

• US 8,007,529 B2
• Filed: 08/01/2008
• Issued: 08/30/2011
• Est. Priority Date: 04/15/1997
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Yan, John Y.
• Primary Examiner(s): Isabella; David
• Assistant Examiner(s): Swaminathan; Seema
• Application Number:
  US12/184,347
• Publication Number:
  US 20080288058A1
• Time in Patent Office: 1,124 Days
• Field of Search: 623/1.15, 623/1.4, 623/1.42, 623/1.44, 623/1.5, 623/1.51, 623/1.53, 623/1.39
• US Class Current: 623/1.39
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• 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 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 2300/416 Anti-neoplastic or anti-proliferative or anti-restenosis or anti-angiogenic agents, e.g. paclitaxel, sirolimus
• CPC Class Codes: A61L 2300/45 Mixtures of two or more drugs, e.g. synergistic mixtures
• CPC Class Codes: A61L 2300/602 Type of release, e.g. controlled, sustained, slow
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: Y10T 29/49982 Coating
• CPC Class Codes: Y10T 428/12153 Interconnected void structure [e.g., permeable, etc.]
• CPC Class Codes: Y10T 428/12479 Porous [e.g., foamed, spongy, cracked, etc.]

Abstract

A porous prosthesis for delivering a medication to the site of implantation. The prosthesis, such as a stent, includes a first porous region and a second porous region and is at least partially formed from a molybdenum-rhenium alloy. The porous regions can have different porosity. A stent includes first, second and third porous region, the first porous region being between the second and third porous regions, and a therapeutic agent is disposed in the first porous region. A stent can also include a solid core and inner and outer porous layers surrounding the core.

Claims

1. A stent comprising:

a body substantially formed of a molybdenum-rhenium alloy including an interconnected network of struts,

wherein the struts include a metallic core formed by large diameter particles defining a first porous region, and a second porous region and a third porous region formed by smaller diameter particles, such that the first porous region is disposed between the second porous region and third porous region and the average pore size of the first porous region is greater than the average pore size of the second porous region and the average pore size of the third porous region.

2. The stent of claim 1, wherein the struts are self-expandable or balloon expandable.

3. A stent comprising a strut element, the strut element being at least partially formed of a molybdenum-rhenium alloy,

wherein the strut element includes a solid metallic inner core having an inner side and an opposed, outer side,

an outer layer disposed on the outer side, the outer layer being a first porous layer of metallic material formed by particles, filaments or fibers sintered to the inner core, and

an inner layer disposed on the inner side, the inner layer being a second porous layer of metallic material formed by particles, filaments or fibers sintered to the inner core,

wherein the strut is formed from a metallic sheet such that the solid core causes a therapeutic agent loaded into the second porous layer to flow only in a radially inward direction after the stent has been implanted in a vessel, and

wherein the stent is configured for being radially expanded by a balloon and for providing support to a body vessel after the stent has been radially expanded by the balloon.

4. The stent of claim 3, wherein the outer layer is capable of contacting the inner wall of the vessel when the stent has been implanted in the vessel.

5. The stent of claim 3, wherein the outer layer is formed by sintering metallic particles.

6. The stent of claim 3, wherein the outer layer has a porosity greater than 0.30.

7. The stent of claim 3, wherein the outer layer is formed by sintering a matrix of overlapping metallic filaments.

8. A stent comprising:

a body at least partially formed of a molybdenum-rhenium alloy including an interconnected network of struts,

wherein the struts include a first porous metallic layer, a second porous metallic layer, and a metallic core, and

the first and second layers are located on opposite sides of the metallic core,

the first porous layer is formed from particles having a first diameter, thereby forming a first average pore size,

the second porous layer is formed from particles having a second diameter, thereby forming a second average pore size, and

the first average pore size is greater than the second average pore size.

9. The stent of claim 8, wherein a therapeutic agent is disposed within the first or second porous outer layer.

10. The stent of claim 8, wherein the stent is self-expandable or balloon expandable.

11. A stent comprising:

a body substantially formed of a molybdenum-rhenium alloy including an interconnected network of struts,

wherein the struts include a second porous region, a third porous region, and a first porous region disposed between the second porous region and third porous region,

wherein the average pore size of the first porous region is greater than the average pore size of the second porous region and the average pore size of the third porous region, and

wherein the stent has a therapeutic agent loaded into the first porous region, and

wherein the first porous region is devoid of a polymer layer for purposes of delivering therapeutic agents.