Stent and method for drug delivery from stents

• US 20020128704A1
• Filed: 02/19/2002
• Published: 09/12/2002
• Est. Priority Date: 03/07/2001
• Status: Abandoned Application

• Current Assignee: Monica L.B. Anderson, Rudy A. Mazzocchi, Wolfgang Daum
• Original Assignee: Monica L.B. Anderson, Rudy A. Mazzocchi, Wolfgang Daum
• Inventors: Daum, Wolfgang, Mazzocchi, Rudy A., Anderson, Monica L.B.
• Application Number:
  US10/078,622
• Publication Number:
  US 20020128704A1
• Time in Patent Office: Days
• US Class Current: 623/1.15
• 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 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 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: A61M 2025/0057 Catheters delivering medicament other than through a conventional lumen, e.g. porous walls or hydrogel coatings
• CPC Class Codes: A61M 2205/36 related to heating or cooling

Abstract

A method for controlling the activity of drugs on or in drug-coated or drug-loaded implantable devices, such as stents or other metallic devices, uses non-invasive, inductive heating of such device. The heating of a device, such as stent, can be used to release drugs applied to the stent in release layers, to activate drugs on the stent that have little or no activity at body temperature and to enhance for defined periods the reaction environment at the stent for drug-adjacent tissue interactions. Reverse effects of deactivation of drugs upon heating are also possible.

Claims

1. An implant for delivery of a drug, comprising:

an implant body capable of heating by exposure to an electromagnetic field; and

a drug material applied to the implant body, said drug material being substantially effective only when the implant has been heated by exposure to the electromagnetic field and heat energy from the implant has heated the drug material.

2. The implant of claim 1, wherein the drug material is a drug ingredient combined with a heat sensitive release material, and the drug material becomes effective after the release material releases a portion of the drug ingredient.

3. The implant of claim 1, wherein the drug material is a drug ingredient adhered to the implant that is substantially inactive at normal body temperature and that becomes active after the implant has heated the drug ingredient to a temperature where is substantially active.

4. The implant of claim 1, wherein the drug material is a drug ingredient that is to be delivered to tissue adjacent the implant and drug-tissue interaction is enhanced when heat from the implant causes tissue adjacent the implant to rise above normal body temperature when the drug ingredient is present.

5. The implant of claim 1, wherein the implant is a stent and the drug material comprises an active ingredient that inhibits restenosis in the stent.

6. A method of using a drug-coated or drug-loaded implant by heating the implant above a certain temperature at which drug activity in the tissue adjacent the implant starts and maintaining that temperature for a specified period of time.

7. The method of claim 6, wherein the implant is heated by radio frequency (RF) energy.

8. The method as recited in claim 6, wherein the RF energy is generated by a sending antenna outside the patient'"'"'s body transferring energy to the implant.

9. A method as cited in claim 6, wherein a sending antenna is placed inside the implant by an endovascular catheter inserted through vessels.

10. A method as recited in claim 6, wherein the drug activity is inhibiting proliferation of cells that cause restenosis.

11. An implant for delivery of a drug, comprising:

an implant body capable of heating by exposure to an electromagnetic field; and

a supply of drug material applied to the implant body, said drug material being substantially ineffective after the implant has been heated by exposure to the electromagnetic field and heat energy from the implant has heated the drug material.

12. The implant of claim 11, wherein the drug material is a drug ingredient combined with a heat sensitive release material and the drug material becomes ineffective after the release material is heated.

16. The apparatus of claim 15, wherein heating of the implantable member is invasive and is accomplished by applying a magnetic field over the body.

17. The apparatus of claim 16, wherein the elution of the drug from the implantable member is to treat prostate disease.

18. The apparatus of claim 16, wherein the elution of the drug from the implantable member is to treat diabetic disease.

19. The apparatus of claim 16, wherein the elution of the drug from the implantable member is to treat ophthalmic disease.

13. A metallic implant for delivery of a drug, comprising:

a body capable of being heated; and

a layer of drug material applied to the body, said drug material being effective while being heated.

14. A method of using a drug-coated or drug-loaded implant by heating the implant above a certain temperature at which drug activity in the tissue adjacent the implant is substantially enhanced and maintaining that temperature for a specified period of time.

15. An apparatus for delivery of a drug in a body comprising an implantable member with the drug, the member being implanted in the body and controllably heated to elute the drug off of the member to treat the body, wherein the drug is operative when the member is heated.

20. A method of delivering a drug in a body by controllably heating an implantable member with the drug to elute the drug from the member to treat the body, wherein the drug is operative when the member is heated.

21. An implantable device having at least one coated drug material capable of being heated inductively and delivering the drug material to a body when heated.

22. The device of claim 21, wherein frequency of inductive heat is below 1 MHz.

23. The device of claim 21, wherein the implantable device is a prosthetic device.