Controlled release device and method using electrothermal ablation

• US 7,455,667 B2
• Filed: 10/26/2005
• Issued: 11/25/2008
• Est. Priority Date: 08/16/2002
• Status: Expired due to Term

• Current Assignee: DARE MB Incorporated
• Original Assignee: MicroCHIPS Inc.
• Inventors: Sheppard, Norman F. Jr., Maloney, John M., Uhland, Scott A., Yomtov, Barry Y., Herman, Stephen J., Polito, Benjamin F.
• Primary Examiner(s): Lucchesi; Nicholas D
• Assistant Examiner(s): Stigell; Theodore J
• Application Number:
  US11/259,301
• Publication Number:
  US 20060100608A1
• Time in Patent Office: 1,126 Days
• Field of Search: 604/890.1, 604/500, 604/891.1, 604/892.1, 604/20, 604/21, 604 65- 67, 604/69, 604/93.01, 604/244, 604/246, 604/256, 604285-288, 60428801-28804, 604/502, 436174-175
• US Class Current: 604/890.1
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61M 2005/1726 the body parameters being measured at, or proximate to, the infusion site
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/123 with incorporated reservoirs
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 25/0069 Tip not integral with tube
• CPC Class Codes: A61M 25/0082 Catheter tip comprising a tool
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/32 alternating or intermittent currents applying electric fields by inductive or capacitive coupling A61N1/40; microwave apparatus A61N5/02
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

Devices and methods are provided for the controlled release or exposure of reservoir contents. The device includes a reservoir cap formed of an electrically conductive material, which prevents the reservoir contents from passing out from the device and prevents exposure of the reservoir contents to molecules outside of the device; an electrical input lead connected to said reservoir cap; and an electrical output lead connected to said reservoir cap, such that upon application of an electrical current through the reservoir cap, via the input lead and output lead, the reservoir cap ruptures to release or expose the reservoir contents. The reservoir contents can comprise a release system containing drug molecules for release or can comprise a secondary device, such as a sensor. In one embodiment, the controlled release system is incorporated into an implantable drug delivery device.

Claims

1. A method for the controlled delivery of molecules comprising:

positioning at a preselected location a device which includes a substrate having at least one discrete reservoir in which the molecules for delivery are stored, and a discrete reservoir cap in register with an opening in the reservoir and formed of an electrically conductive material which prevents said molecules for delivery from passing out from the device; and

applying an electrical current through said reservoir cap, via an electrical input lead and an electrical output lead which are electrically connected to and directly contact said reservoir cap, to rupture the reservoir cap and not the substrate to enable the molecules to pass outward from the device to the preselected location.

2. The method of claim 1, wherein the device is an implantable medical device.

3. The method of claim 2, wherein the molecules for delivery comprise drug molecules.

4. The method of claim 3, wherein the drug molecules comprise a human parathyroid hormone.

5. The method of claim 2, wherein the molecules for delivery comprise a therapeutic or prophylactic agent and the preselected location comprises an intrathecal, intracranial, abdominal/peritoneal, thoracic, intrapericardial, renal, or hepatic space.

6. The method of claim 5, wherein the drug molecules comprise human parathyroid hormone hPTH(1-34).

7. The method of claim 1, wherein the reservoir caps comprise at least one metal film.

8. The method of claim 7, wherein the reservoir caps comprise titanium, platinum, gold, or a combination thereof.

9. The method of claim 1, wherein the substrate comprises silicon.

10. The method of claim 1, wherein the application of electrical current through the reservoir cap causes the temperature of the reservoir cap to increase preferentially compared to the temperature of the leads.

11. The method of claim 1, wherein the reservoir cap is formed of a material having a melting point which differs from the melting point of the material forming the leads.

12. The method of claim 1, wherein the reservoir cap has a smaller cross-sectional area in the direction of electric current flow than that of the leads.

13. The method of claim 1, wherein the leads and the reservoir cap have substantially the same thickness, and the ratio of the width of the leads to the width of the reservoir cap is 2:

1 or more.

14. The method of claim 1, wherein the reservoir cap comprises multiple layers of metal or multiple layers of metal and semiconductor.

15. The method of claim 1, further comprising detecting an open electrical circuit between the leads of a reservoir cap that has been ruptured, to verify reservoir opening.

16. The method of claim 1, wherein the drug molecules comprise parathyroid hormone.

17. A method for the controlled delivery of molecules comprising:

positioning at a preselected location a device which comprises a substrate, a plurality of discrete reservoirs disposed in the substrate, reservoir contents which comprise the molecules for delivery located in said plurality of reservoirs, an electrically conductive, discrete reservoir cap covering an opening in each reservoir, a conducting input lead and a conducting output lead each of which are electrically connected to and directly contact each reservoir cap, and a source of electric power; and

then

applying an electrical current from the power source through said reservoir cap, via the conducting leads, to rupture the reservoir cap by electrothermal ablation and not rupture the substrate, thereby enabling the molecules to pass outward from the device to the preselected location.

18. The method of claim 17, wherein the device is an implantable medical device.

19. The method of claim 18, wherein the molecules for delivery comprise drug molecules.

20. The method of claim 19, wherein the drug molecules comprise a human parathyroid hormone.

21. The method of claim 18, wherein the molecules for delivery comprise a therapeutic or prophylactic agent, and the preselected location comprises an intrathecal, intracranial, abdominal/peritoneal, thoracic, intrapericardial, renal, or hepatic space.

22. The method of claim 21, wherein the drug molecules comprise human parathyroid hormone hPTH(1-34).

23. The method of claim 17, wherein the reservoir caps comprise at least one metal film.

24. The method of claim 23, wherein the reservoir caps comprise titanium, platinum, gold, or a combination thereof.

25. The method of claim 23, wherein the substrate comprises silicon.

26. The method of claim 17, wherein the reservoirs are microreservoirs.

27. The method of claim 17, wherein the drug molecules comprise parathyroid hormone.

28. A method for the controlled exposure of reservoir contents comprising:

positioning at a preselected location a device which includes a substrate having at least one discrete reservoir in which the reservoir contents for exposure are disposed, and a discrete reservoir cap in register with the at least one reservoir and formed of an electrically conductive material which prevents exposure of said reservoir contents to molecules outside of the device; and

applying an electrical current through said reservoir cap, via an electrical input lead and an electrical output lead which are electrically connected to and directly contact said reservoir cap, to rupture the reservoir cap and not the substrate to expose the reservoir contents to said molecules at the preselected location.

29. The method of claim 28, wherein the device is an implantable medical device.

30. The method of claim 29, wherein the reservoir contents comprises a sensor or sensor component.

31. The method of claim 30, wherein the sensor or sensor component can detect in a patient in vivo glucose, urea, calcium, or a hormone.

32. The method of claim 29, wherein the preselected location comprises an intrathecal, intracranial, abdominal/peritoneal, thoracic, intrapericardial, renal, or hepatic space.

33. The method of claim 28, wherein the reservoir cap comprises at least one metal film.

34. The method of claim 33, wherein the reservoir cap comprises titanium, platinum, gold, or a combination thereof.

35. The method of claim 28, wherein the substrate comprises silicon.

36. The method of claim 28, wherein the application of electrical current through the reservoir cap causes the temperature of the reservoir cap to increase preferentially compared to the temperature of the leads.

37. The method of claim 28, wherein the reservoir cap is formed of a material having a melting point which differs from the melting point of the material forming the leads.

38. The method of claim 28, wherein the reservoir cap has a smaller cross-sectional area in the direction of electric current flow than that of the leads.

39. The method of claim 28, wherein the leads and the reservoir cap have substantially the same thickness, and the ratio of the width of the leads to the width of the reservoir cap is 2:

1 or more.

40. The method of claim 28, wherein the reservoir cap comprises multiple layers of metal or multiple layers of metal and semiconductor.

41. The method of claim 28, further comprising detecting an open electrical circuit between the leads of a reservoir cap that has been ruptured, to verify reservoir opening.

42. A method for the controlled exposure of reservoir contents comprising:

positioning at a preselected location a device which comprises a substrate, a plurality of reservoirs disposed in the substrate, reservoir contents which comprise a secondary device located in said plurality of reservoirs, an electrically conductive, discrete reservoir cap covering an opening in each reservoir, a conducting input lead and a conducting output lead each of which are electrically connected to and directly contact each reservoir cap, and a source of electric power; and

then

applying an electrical current from the power source through said reservoir cap, via the electrical input lead and the electrical output leads, to rupture the reservoir cap by electrothermal ablation and not rupture the substrate, thereby exposing the secondary device to molecules at the preselected location.

43. The method of claim 42, wherein the device is an implantable medical device.

44. The method of claim 43, wherein the secondary device comprises a sensor or sensor component.

45. The method of claim 44, wherein the sensor or sensor component can detect in a patient in vivo glucose, urea, calcium, or a hormone.

46. The method of claim 43, wherein the preselected location comprises an intrathecal, intracranial, abdominal/peritoneal, thoracic, intrapericardial, renal, or hepatic space.

47. The method of claim 42, wherein the reservoirs are microreservoirs.

48. A method for the controlled exposure of a sensor comprising:

providing a device which includes at least one reservoir provided in a substrate, at least one sensor located in the at least one reservoir, at least one reservoir cap, which comprises a metal, closing off at least one opening in each reservoir to seal the at least one sensor within the reservoir, an electrical input lead and an electrical output lead which are electrically connected to and directly contact the reservoir cap, and a source of electric power; and

applying an electrical current from the power source through the at least one reservoir cap, via said pair of conductive leads, in an amount effective to rupture the reservoir cap by electrothermal ablation and not rupture the substrate, thereby exposing the at least one sensor.

49. The method of claim 48, wherein the device is implanted into a patient and the sensor detect a physiological condition in the patient.

50. The method of claim 48, wherein the sensor is a biosensor which detects an analyte in the patient.

51. The method of claim 50, wherein the analyte comprises glucose, urea, calcium, or a hormone.