Biodegradable drug delivery vascular stent

• US 20020099434A1
• Filed: 03/28/2002
• Published: 07/25/2002
• Est. Priority Date: 10/04/1991
• Status: Active Grant

• Current Assignee: Scimed Life Systems Incorporated Boston Scientific Corporation
• Original Assignee: Scimed Life Systems Incorporated Boston Scientific Corporation
• Inventors: Wang, Lixiao, Buscemi, Paul J., Stejskal, Elizabeth A., Palme, Donald F. II
• Granted Patent: US 6,869,443 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• 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 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0023 operated at different temperatures whilst inside or touching the human body, heated or cooled by external energy source or cold supply
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: A61L 2300/42 Anti-thrombotic agents, anticoagulants, anti-platelet agents
• CPC Class Codes: A61L 2300/604 Biodegradation
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 2300/622 Microcapsules
• CPC Class Codes: A61L 31/041 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 31/044 Collagen
• CPC Class Codes: A61L 31/047 Other specific proteins or polypeptides not covered by A61L31/044 - A61L31/046
• 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: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device

Abstract

A stent includes a main body of a generally tubular shape for insertion into a lumen of a vessel of a living being. The tubular main body includes a substantially biodegradable matrix having collagen IV and laminin that enclose voids within the matrix. The tubular main body also includes a biodegradable strengthening material in contact with the matrix to strengthen the matrix. The tubular main body is essentially saturated with drugs.

Claims

1. A stent having a generally tubular main body for insertion into a lumen of a vessel of a living being wherein the tubular main body comprises a substantially biodegradable matrix that includes collagen IV and laminin that enclose voids within the matrix, and a biodegradable strengthening material in contact with the matrix to strengthen the matrix, the tubular main body being essentially saturated with drugs.

2. The stent of claim 1 wherein the biodegradable strengthening material includes polylactic acid.

3. The stent of claim 1 wherein the strengthening material includes particles dispersed within the biodegradable matrix.

4. The stent of claim 1 wherein the strengthening material includes a layer attached to the matrix.

5. The stent of claim 1 wherein the drugs are included in the biodegradable matrix.

6. The stent of claim 1 wherein the drugs are included in the voids within the biodegradable matrix.

7. The stent of claim 1 wherein the drugs are included within the biodegradable strengthening material.

8. The stent of claim 1 wherein the drugs include microencapsulated drugs.

9. The stent of claim 1 wherein the biodegradable matrix further includes a glycosaminoglucuronan.

10. The stent of claim 9 wherein the glycosaminoglucuronan includes heparin.

11. The stent of claim 1 and further having an exterior surface for contacting the vessel when the main body is placed in a living being, a cambered interior surface contacting a fluid passing through the lumen of the vessel, a leading end facing a direction of flow and a trailing end wherein the main body has substantially the same thickness at the leading end as at the trailing end.

12. The stent of claim 11 and further including a water soluble coating that overlays the interior surface.

13. The stent of claim 1 wherein the tubular main body is a coiled strip.

14. The coiled strip of claim 13 and further including a meltable film coating that melts upon application of the energy and that overlays the interior surface.

15. The stent of claim 1 wherein the biodegradable strengthening material is treated by an application of energy of a magnitude ineffective to cause bonding with living tissue of the lumen while the stent is in the lumen.

16. The stent of claim 15 wherein the energy causes an increase in temperature of the biodegradable strengthening material above a glass transition temperature of the biodegradable strengthening material.

17. The stent of claim 15 wherein the biodegradable strengthening material is treated by application of mechanical energy of a magnitude less than an elastic limit of the biodegradable strengthening material.

18. The stent of claim 15 and further including a plurality of microcapsules within the biodegradable strengthening material, the microcapsules containing a material inducing crosslinking of the biodegradable strengthening material wherein the application of energy causes a rupture of the microcapsules and a releasing of the material inducing crosslinking of the biodegradable strengthening material.

19. A method for positioning a stent having a tubular main body made of a substantially biodegradable matrix that includes collagen IV and laminin that enclose voids within the matrix, and a biodegradable strengthening material in contact with the matrix to strengthen the matrix, the method comprising:

positioning the tubular main body having a first diameter around and about a balloon of a catheter;

moving the balloon to a site within a lumen of a vessel of a living being;

expanding the tubular main body by an expansion of the balloon to increase the first diameter of the tubular main body to a second diameter;

applying energy to the tubular main body to harden the biodegradable strengthening material;

cooling the tubular main body; and

releasing the stent from the balloon.

20. A method for making a biodegradable stent for insertion into a lumen of a vessel of a living being, comprising:

casting a film that includes a matrix of collagen IV and laminin;

drying the film;

casting a film that includes polylactic acid onto the dried film that includes the matrix of collagen IV and laminin to form a stent material;

drying the stent material; and

forming the stent material into the biodegradable stent.

21. The method of claim 20 and further including plasma treating the film including the matrix of collagen IV and laminin after drying the film and before casting the film that includes polylactic acid onto the dried film.