Composite stent

• US 9,101,505 B2
• Filed: 10/31/2007
• Issued: 08/11/2015
• Est. Priority Date: 04/27/2006
• Status: Active Grant

• Current Assignee: Brs Holdings, LLC
• Original Assignee: Brs Holdings, LLC
• Inventors: Johnson, James R., Tavakley, Anita
• Primary Examiner(s): PELLEGRINO, BRIAN E
• Application Number:
  US11/932,531
• Publication Number:
  US 20080077222A1
• Time in Patent Office: 2,841 Days
• Field of Search: 623/1.13, 623/1.39, 623/1.41, 623/1.44, 623/1.46, 623/1.49, 623/23.56, 623/23.7, 606/77, 606/154, 606/908
• US Class Current: 1/1
• 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 2/92 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 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2230/0091 helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61L 31/005 Ingredients of undetermined constitution or reaction products thereof
• CPC Class Codes: A61L 31/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/127 containing fillers of phosphorus-containing inorganic materials
• CPC Class Codes: A61L 31/128 containing other specific inorganic fillers not covered by A61L31/126 or A61L31/127
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29K 2067/043 PGA, i.e. polyglycolic acid or polyglycolide
• CPC Class Codes: B29K 2067/046 PLA, i.e. polylactic acid or polylactide
• CPC Class Codes: B29K 2505/08 Transition metals
• CPC Class Codes: B29K 2509/00 Use of inorganic materials not provided for in groups B29K2503/00 - B29K2507/00, as filler
• CPC Class Codes: B29L 2031/7546 Surgical equipment
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2264/104 : Oxysalt, e.g. carbonate, sulfate, phosphate or nitrate particles
• CPC Class Codes: B32B 2367/00 : Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2535/00 : Medical equipment, e.g. bandage, prostheses, catheter medical patches B32B2556/00
• CPC Class Codes: B32B 27/18 : characterised by the use of special additives
• CPC Class Codes: B32B 27/36 : comprising polyesters
• CPC Class Codes: B32B 37/06 : characterised by the heating method
• CPC Class Codes: C08L 67/04 : Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence

Abstract

A bioremovable composite stent includes bioremovable polymer and bioremovable ceramic flakes generally coupled with adjacent layers of bioremovable polymer so as to make a resilient composite stent configured to move between a contracted configuration to an expanded configuration. In one embodiment, the composite stent may have a helical shape.

Claims

1. A composite stent comprising:

a plurality of layers that include bioremovable polymer; and

a plurality of flakes of bioremovable ceramic material, the flakes having a length and a thickness defining an aspect ratio;

wherein the plurality of layers alternate between having a high concentration of the plurality of flakes and having a low concentration of the plurality of flakes; and

wherein the composite stent is expandable.

2. The composite stent of claim 1 wherein the bioremovable ceramic material includes tricalcium phosphate.

3. The composite stent of claim 1 wherein the bioremovable polymer includes polylactide, polyglycolide, polycaprolactone, and/or copolymers thereof.

4. The composite stent of claim 1 wherein each of the plurality of flakes is porous.

5. The composite stent of claim 4 comprising a bioactive agent positioned in the pores of the plurality of flakes.

6. The composite stent of claim 1 wherein the aspect ratio of the plurality of flakes is 5 to 300.

7. The composite stent of claim 1 wherein the plurality of flakes provide strength, stiffness, or a combination thereof to the composite stent in the direction of both the width and length of the layers possessing flakes.

8. A composite stent comprising:

bioremovable polymer; and

a plurality of flakes of bioremovable ceramic material included in the bioremovable polymer, the flakes having a length and a thickness defining an aspect ratio;

wherein the composite stent has a helical shape; and

wherein the composite stent is resilient and resilient properties of the stent cause it to move from a contracted configuration to an expanded configuration.

9. The composite stent of claim 8 wherein the composite stent is wound and in a state of tension in the contracted configuration and the composite stent is at least substantially unwound and not in a state of tension in the expanded configuration.

10. The composite stent of claim 8 wherein the composite stent has a plurality of openings in it.

11. The composite stent of claim 8 comprising a first layer that includes the plurality of flakes of bioremovable ceramic material embedded in the bioremovable polymer and a second layer of bioremovable polymer coupled to the first layer, the second layer having a plurality of flakes of bioremovable ceramic material embedded in the bioremovable polymer, the second layer having a concentration of flakes of bioremovable ceramic powder different than the first.

12. The composite stent of claim 8 wherein the aspect ratio of the plurality of flakes is 5 to 300.

13. A composite stent comprising a plurality of flakes of bioremovable ceramic material embedded in bioremovable polymer, the flakes having a length and a thickness defining an aspect ratio and wherein the bioremovable polymer forms a bioremovable stent.

14. The composite stent of claim 13 wherein the bioremovable ceramic material includes tricalcium phosphate.

15. The composite stent of claim 13 wherein the composite stent is coated with stem cells.

16. The composite stent of claim 13 wherein the aspect ratio of the plurality of flakes is 5 to 300.

17. The composite stent of claim 13 wherein the aspect ratio of the plurality of flakes is 10 to 20.

18. The composite stent of claim 13 comprising a first layer that includes the plurality of flakes and a second layer of bioremovable polymer coupled to the first layer, the second layer being substantially free or completely free of any bioremovable ceramic material.

19. The composite stent of claim 13 wherein each of the plurality of flakes is porous.

20. The composite stent of claim 19 comprising a bioactive agent positioned in the pores of the plurality of flakes.

21. The composite stent of claim 20 wherein the bioactive agent includes heparin, prostacyclin, angiopeptin, and/or methotrexate.

22. The composite stent of claim 13 wherein the flakes of bioremovable ceramic material are oriented in parallel.

23. A method of using a composite stent comprising:

positioning the composite stent in a bodily lumen, the composite stent including bioremovable polymer and a plurality of flakes of bioremovable ceramic material, the flakes having a length and a thickness defining an aspect ratio, the composite stent being in a contracted configuration where the composite stent is coiled in a state of tension; and

releasing the composite stent so that the resilient properties of the composite stent cause the composite stent to expand in the bodily lumen.