Biodegradable drug delivery material for stent

• US 7,470,283 B2
• Filed: 01/10/2003
• Issued: 12/30/2008
• Est. Priority Date: 04/13/2000
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Dutta, Debashis
• Primary Examiner(s): Woo; Julian W
• Assistant Examiner(s): Nguyen; Victor X
• Application Number:
  US10/340,157
• Publication Number:
  US 20030097173A1
• Time in Patent Office: 2,181 Days
• Field of Search: 623/1.13, 623/1.42, 623/1.43, 623/1.46, 623/1.18, 623/1.19, 623/1.38, 623/1.44, 623/1.12, 427/2.25, 424/426
• US Class Current: 623/1.46
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body

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 coated stent comprising:

a stent body in a size suitable for implantation in a blood vessel; and

a coating covering at least a portion of the stent body, the coating including a biodegradable terpolymer having three different types of units from three different monomers and comprising anhydride-derived and imide-derived units,

wherein the terpolymer is bulk-erosion resistant when implanted into a lumen of a patient and subjected to blood flow.

2. The coated stent of claim 1 wherein the terpolymer comprises a polyanhydride or a polyorthoester.

3. The coated stent of claim 1 wherein the terpolymer is loaded with a pharmacological agent.

4. The coated stent of claim 3 wherein the pharmacological agent comprises heparin.

5. A coated stent comprising:

a stent body in a size suitable for use in a blood vessel; and

a coating covering at least a portion of the stent body, the coating including a biodegradable terpolymer having three different types of units from three different monomers and comprising anhydride-derived and imide-derived units in the amount of 20% to 40% of the polymer,

wherein the terpolymer is bulk-erosion resistant when implanted into a lumen of a patient and subjected to blood flow.

6. The coated stent of claim 5 wherein the polymer is hydrophobic.

7. The coated stent of claim 5 wherein the coating additionally includes a pharmacological agent.

8. The coated stent of claim 7 wherein the pharmacological agent comprises heparin.

9. The coated stent of claim 7 wherein after the stent is implanted into a lumen of a patient and the coating is subjected to blood flow, the pharmacological agent is gradually released from the coating.

10. The coated stent of claim 5 wherein the stent body comprises a metallic material.

11. A coated stent comprising:

a stent body; and

a coating covering at least a portion of the stent body, the coating including a biodegradable terpolymer having three different types of units from three different monomers and comprising anhydride-derived and imide-derived units in the amount of 20% to 40% of the polymer,

wherein the terpolymer is bulk-erosion resistant when implanted into a lumen of a patient and subjected to blood flow, and

wherein the terpolymer has a degradation rate that is faster than the rate of water penetration into the interior of the polymer after the stent is implanted into the lumen of the patient.

12. A coated stent comprising:

a stent body; and

a coating covering at least a portion of the stent body, the coating including a biodegradable terpolymer having three different types of units from three different monomers and comprising anhydride-derived and imide-derived units in the amount of 20% to 40% of the polymer,

wherein the terpolymer is bulk-erosion resistant when implanted into a lumen of a patient and subjected to blood flow, and

wherein the terpolymer further comprises a biodegradable polymer comprising fragments having water-labile ester or imide bonds.