METHOD AND APPARATUS FOR TREATING ISCHEMIC DISEASES

• US 20100168646A1
• Filed: 01/22/2008
• Published: 07/01/2010
• Est. Priority Date: 01/22/2007
• Status: Active Grant

• Current Assignee: University of Southern California, UT-Battelle LLC
• Original Assignee: University of Southern California
• Inventors: Greenbaum, Elias, Tai, Yu-Chong, Humayun, Mark S.
• Granted Patent: US 8,209,024 B2
• Time in Patent Office: Days
• US Class Current: 604/20
• CPC Class Codes: A61N 1/20 continuous direct currents
• CPC Class Codes: A61N 1/205 for promoting a biological process
• 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: A61N 1/326 for promoting growth of cells, e.g. bone cells
• CPC Class Codes: A61P 27/02 Ophthalmic agents
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: A61P 9/10 for treating ischaemic or atherosclerotic diseases, e.g. antianginal drugs, coronary vasodilators, drugs for myocardial infarction, retinopathy, cerebrovascula insufficiency, renal arteriosclerosis

Abstract

The present invention relates to the treatment of ischemic diseases, and more particularly, to treatment of diabetic retinopathy and ischemia of the retinal and choroidal tissues. The treatment, which will work in vitrectomized eyes as well as non-vitrectomized eyes, is based on selective and fractional electrolysis of the vitreous humor to produce oxygen and optionally active chlorine while simultaneously controlling pH. Oxygen or active chlorine can suppress or reverse the onset of diabetic retinopathy, other retinovascular diseases, and choroidal neovascularization.

Claims

1. A method of treating ischemic tissue in a mammal, the method comprising electrolysis of biological fluid proximal to and/or within ischemic tissue present in said mammal such that oxygen is supplied to the ischemic body tissue.

2. The method of claim 1, wherein formation of chlorinous substances in biological fluid undergoing electrolysis is controlled.

3. The method of claim 1, wherein pH of the biological fluid undergoing electrolysis is controlled.

4. The method of claim 1, wherein electrolysis is performed by implanting and electrically operating an anode and a first cathode in electrical contact with said anode in biological fluid proximal to or within ischemic body tissue.

5. The method of claim 4, wherein formation of chlorinous substances in biological fluid undergoing electrolysis is controlled.

6. The method of claim 5, wherein formation of chlorinous substances is controlled by a pulsed electrolytic technique capable of altering the location or concentration profile of chloride ions within an electrical double layer of the anode electrode so as to permit selective oxidation of water in body tissue to oxygen.

7. The method of claim 6, wherein the pulsed electrolytic technique uses a monophasic, biphasic, or multiphasic electrical pulse technique.

8. The method of claim 7, wherein the technique comprises a monophasic positive pulse having a duration shorter than the kinetic relaxation time constant for reestablishing the electrical double layer.

9. The method of claim 6, wherein a positive pulse having a duration shorter than the kinetic relaxation time constant for reestablishing the electrical double layer at the anode is preceded by a negative pulse to heighten chloride depletion from water at the electrode surface.

10. The method of claim 6, wherein the technique comprises a positive pulse for oxidation of water followed by a negative pulse of sufficient duration and voltage for reducing any remaining chlorinous substances to chloride ion salts.

11. The method of claim 4, wherein pH of the body fluid undergoing electrolysis is controlled.

12. The method of claim 11, wherein pH is controlled by electrolytic means.

13. The method of claim 12, wherein the electrolytic means further comprises a second cathode electrode located and electrically operated in tissue proximal to the anode and first cathode located and operated within tissue proximal to or within ischemic tissue, said second cathode electrode in electrical contact with the anode and first cathode, and a pH and/or oxygen sensor operated within tissue proximal to or within ischemic tissue and in electrical contact with the anode, first cathode, and second cathode in such a manner that feedback information from the pH and/or oxygen sensor will cause either the anode and first cathode, or the second cathode, or both, to operate at any given time.

14. The method of claim 1, wherein the ischemic tissue is located in an eye and the biological fluid is vitreous humor.

15. An apparatus for delivering oxygen to ischemic tissue of a mammal, the apparatus comprising a tissue-implantable electrochemical system comprising an anode electrode in electrical contact with a first cathode electrode, the electrochemical system capable of electrolytic production of oxygen from biological fluid proximal to or within ischemic tissue in the mammal when connected to a power supply source.

16. The apparatus of claim 15, wherein the apparatus further comprises means for controlling the formation of chlorinous substances in biological fluid undergoing electrolysis.

17. The apparatus of claim 16, wherein the means for controlling the formation of chlorinous substances is an electrode pulse generator in contact with the anode electrode.

18. The apparatus of claim 15, wherein the apparatus further comprises means for controlling pH of body fluid undergoing electrolysis.

19. The apparatus of claim 18, wherein the means for controlling pH of body fluid undergoing electrolysis is a second cathode electrode designed to be implanted and electrically operated in biological fluid of tissue proximal to the anode and first cathode located and operated within biological fluid of tissue proximal or within to ischemic tissue, said second cathode electrode being in electrical contact with the anode and first cathode during operation, and a pH and/or oxygen sensor capable of being operated within biological fluid in tissue proximal to or within ischemic tissue and in electrical contact with the anode, first cathode, and second cathode during operation in such a manner that feedback information from the pH and/or oxygen sensor will cause either the anode and first cathode, or the second cathode, or both, to operate at any given time.

20-22. -22. (canceled)