Drug elution for in vivo protection of bio-sensing analytes

Abstract

A sensor (e.g., an optical sensor) that may be implanted within a living animal (e.g., a human) and may be used to measure an analyte (e.g., glucose or oxygen) in a medium (e.g., interstitial fluid, blood, or intraperitoneal fluid) within the animal. The sensor may include a sensor housing, an analyte indicator covering at least a portion of the sensor housing, and one or more therapeutic agents. The one or more therapeutic agents may reduce deterioration of the analyte indicator. The one or more therapeutic agents may be incorporated within the analyte indicator, a membrane covering at least a portion of the analyte indicator, and/or one or more drug eluting polymer matrices, which may be external to or within the sensor housing.

What is claimed is: 
     
         1 . A sensor for measurement of an analyte in a medium within a living animal, the sensor comprising:
 a sensor housing;   a light source within the sensor housing configured to emit excitation light;   an analyte indicator covering at least a portion of the sensor housing, wherein the analyte indicator comprises one or more indicator molecules that reversibly bind the analyte, are positioned to be irradiated by the excitation light, and are configured to emit light indicative of the amount of the analyte in the medium within the living animal;   a photodetector within the sensor housing, wherein the photodetector is sensitive to light emitted by the one or more indicator molecules and configured to generate a signal indicative of the amount of the analyte in the medium within the living animal;   at least one drug eluting polymer matrix that is within the sensor housing; and   one or more therapeutic agents that reduce deterioration of the analyte indicator, are dispersed within the drug eluting polymer matrix, and include an anti-inflammatory drug.   
     
     
         2 . The sensor of  claim 1 , wherein the sensor housing is perforated to allow elution of the one or more therapeutic agents. 
     
     
         3 . The sensor of  claim 1 , wherein the drug eluting polymer matrix is within a hole, opening, groove or channel in the sensor housing and wherein the sensor housing has an exposed face to allow the elution of the one or more therapeutic agents. 
     
     
         4 . The sensor of  claim 1 , wherein the drug eluting polymer matrix is in the form of a solid. 
     
     
         5 . The sensor of  claim 1 , wherein the drug eluting polymer matrix has a cylindrical shape. 
     
     
         6 . The sensor of  claim 1 , wherein one or more of the therapeutic agents are incorporated within the drug eluting polymer matrix via one or more covalent bonds that break in the presence of aqueous media and release the one or more therapeutic agents. 
     
     
         7 . The sensor of  claim 1 , wherein one or more of the therapeutic agents are incorporated within the drug eluting polymer matrix via one or more covalent bonds that break through exposure to light and release the one or more therapeutic agents. 
     
     
         8 . The sensor of  claim 7 , wherein the covalent bonds break through exposure to light emitted by the light source. 
     
     
         9 . The sensor of  claim 1 , wherein the analyte indicator is located in a polymer matrix. 
     
     
         10 . The sensor of  claim 9 , wherein one or more therapeutic agents are incorporated in the analyte indicator polymer matrix. 
     
     
         11 . The sensor of  claim 1 , wherein the anti-inflammatory drug is a non-steroidal anti-inflammatory drug. 
     
     
         12 . The sensor of  claim 1 , wherein the one or more therapeutic agents reduce oxidation of the analyte indicator. 
     
     
         13 . The sensor of  claim 1 , further comprising a layer of a catalyst on at least a portion of the analyte indicator, wherein the catalyst is capable of converting hydrogen peroxide into water and oxygen. 
     
     
         14 . The sensor of  claim 1 , wherein the drug eluting polymer matrix is a first drug eluting polymer matrix, the sensor further comprises a second drug eluting polymer matrix, and one or more therapeutic agents are dispersed within the second drug eluting polymer matrix. 
     
     
         15 . The sensor of  claim 14 , wherein the first drug eluting polymer matrix releases the one or more therapeutic agents dispersed within the first drug eluting polymer matrix at a first rate, and the second drug eluting polymer matrix releases the one or more therapeutic agents dispersed within the second drug eluting polymer matrix at a second rate that is different from the first rate. 
     
     
         16 . A sensor for measurement of an analyte in a medium within a living animal, the sensor comprising:
 a sensor housing;   an analyte indicator covering at least a portion of the sensor housing;   a layer of a catalyst on at least a portion of the analyte indicator, wherein the layer of catalyst facilitates the conversion of hydrogen peroxide into water and oxygen;   at least one drug eluting polymer matrix that is within the sensor housing; and   one or more therapeutic agents dispersed within the at least one drug eluting polymer matrix, wherein the one or more therapeutic agents reduce deterioration of the analyte indicator and include an anti-inflammatory drug.   
     
     
         17 . The sensor of  claim 16 , wherein the sensor housing is perforated to allow elution of the one or more therapeutic agents. 
     
     
         18 . The sensor of  claim 16 , wherein the drug eluting polymer matrix is within a hole, opening, groove or channel in the sensor housing, and the sensor housing has an exposed face to allow the elution of the one or more therapeutic agents. 
     
     
         19 . The sensor of  claim 16 , wherein the drug eluting polymer matrix has a cylindrical shape. 
     
     
         20 . A sensor for measurement of an analyte in a medium within a living animal, the sensor comprising:
 a sensor housing;   a light source within the sensor housing configured to emit excitation light;   an analyte indicator covering at least a portion of the sensor housing, wherein the analyte indicator comprises one or more indicator molecules that reversibly bind the analyte, are positioned to be irradiated by the excitation light, and are configured to emit light indicative of the amount of the analyte in the medium within the living animal;   a photodetector within the sensor housing, wherein the photodetector is sensitive to light emitted by the one or more indicator molecules and configured to generate a signal indicative of the amount of the analyte in the medium within the living animal; and   one or more therapeutic agents that reduce deterioration of the analyte indicator and are incorporated within the analyte indicator, and include an anti-inflammatory drug.