Biodegradable drug delivery material for stent

• US 8,109,994 B2
• Filed: 01/02/2008
• Issued: 02/07/2012
• Est. Priority Date: 01/10/2003
• Status: Expired due to Fees

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories), Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Dutta, Debashis
• Primary Examiner(s): Nguyen, Victor
• Application Number:
  US11/968,543
• Publication Number:
  US 20080103583A1
• Time in Patent Office: 1,497 Days
• Field of Search: 424/426, 424/484, 623/1.13, 623/1.15, 623/1.11, 623/1.38, 623/1.43, 623/1.46
• US Class Current: 623/1.46
• 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 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 2300/00 Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
• CPC Class Codes: A61L 31/10 Macromolecular materials
• 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

Abstract

A stent is fabricated utilizing a polymer that is selected for its tendency to degrade from the surface inwardly rather than undergo bulk erosion so as to substantially reduce the risk of large particles becoming detached and being swept downstream. Such polymer is hydrophobic yet has water-labile linkages interconnecting the monomers. Ester or imide bonds are incorporated in the polymer to render the surface degrading materials suitable for use in stent applications. The stent may be coated with such polymer or may be wholly formed therefrom.

Claims

1. A stent constructed of a biodegradable polymer, the polymer comprising polyanhydride or polyorthoester or incorporating imide bonds, wherein the stent degrades from its surface inwardly when subjected to blood flow, such that bulk erosion is effectively precluded, wherein the polymer is loaded with a pharmacological agent;

wherein the polyorthoester polymer includes Poly(4-Hy-droxy-L-Proline ester).

2. The stent of claim 1, wherein the pharmacological agent comprises heparin.

3. A stent constructed of a biodegradable polymer, the polymer comprising polyanhydride or polyorthoester or incorporating imide bonds, wherein the stent degrades from its surface inwardly when subjected to blood flow, such that bulk erosion is effectively precluded, wherein the polymer comprises a polyanhydride, wherein the polymer has an imide content of 20% to 40% of the polymer.

4. A stent constructed of a biodegradable polymer, the polymer comprising polyanhydride or polyorthoester or incorporating imide bonds, wherein the stent degrades from its surface inwardly when subjected to blood flow, such that bulk erosion is effectively precluded, wherein the polymer comprises a polyanhydride, wherein the polyanhydride is formed by polycondensation reactions of at least one of the following monomers sebacic acid, di-ortho-carboxyphenoxy sebacate anhydride, salicylic acid, maleic acid, maleic acid anhydride, L-lactic acid, D,L-lactic acid, L-aspartic acid, 1,3-bis-para-carboxyphenoxy propane, 1,6-bis-para-carbosyphenoxy hexane, or any combination of these.

5. A stent constructed of a biodegradable polymer, the polymer comprising polyanhydride or polyorthoester or incorporating imide bonds, wherein the stent degrades from its surface inwardly when subjected to blood flow, such that bulk erosion is effectively precluded, wherein the polymer comprises a polyanhydride, wherein the polyanhydride polymer is an anhydride-co-imide terpolymer;

wherein the anhydride-co-imide terpolymer comprises;

units derived from trimellitylimido-L-tyrosine;

units derived from sebacic acid; and

units derived from 1,3-bis(para-carboxyphenoxy)propane.