Method for glucose monitoring using fluorescence quenching

• US 8,088,595 B2
• Filed: 03/05/2010
• Issued: 01/03/2012
• Est. Priority Date: 09/28/2005
• Status: Active Grant

• Current Assignee: Penn State Research Foundation
• Original Assignee: Texas A&M University System
• Inventors: Ibey, Bennett L., Yadavalli, Vamsi K., Rounds, Rebecca M., Beier, Hope T., Cote, Gerard L., Pishko, Michael V.
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US12/660,884
• Publication Number:
  US 20100222657A1
• Time in Patent Office: 669 Days
• Field of Search: 435/14
• US Class Current: 435/14
• CPC Class Codes: A61P 3/10 for hyperglycaemia, e.g. antidiabetics
• CPC Class Codes: C12Q 1/54 involving glucose or galactose
• CPC Class Codes: G01N 33/53 Immunoassay; Biospecific binding assay; Materials therefor
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing

Abstract

This disclosure relates to a method of measuring a glucose concentration metric or a glucose metric in a patient by contacting an implantable glucose-sensing device with a test sample, which may be in the patient, under conditions that permit a sugar-binding molecule and a functionalized polymer or nano-particle ligand present throughout the matrix of a hydrogel to interact in a glucose-dependent manner to produce an optical signal resulting from quenching of a first fluorophore linked to the ligand or sugar-binding molecule and having a fluorescent emission spectrum quenched upon binding or release of glucose. Next the first fluorophore may be excited with light of a certain wavelength. Then at least one wavelength of light in the glucose-dependent optical signal from the fluorophore may be detected with a detector to produce a detected light signal, which may be processed to produce a glucose metric, such as a glucose concentration metric.

Claims

1. A method of measuring a glucose concentration metric, said method comprising:

contacting an implantable glucose-sensing device with a test sample under conditions that permit a sugar-binding molecule comprising Concanavalin A, other sugar-binding lectins, glucose binding protein, glucose oxidase, or glucose apo-oxidase, the sugar binding molecule present throughout a matrix of a hydrogel in the glucose-sensing device and a functionalized polymer or functionalized nano-particle ligand present throughout the matrix of the hydrogel in the glucose-sensing device to interact in a glucose-concentration dependent manner to produce a glucose-concentration-dependent optical signal resulting from quenching of a first fluorophore comprising a fluorescein, a rhodamine, a cyanine, or fluorescent dye, the first fluorophore linked to the ligand or sugar-binding molecule and having a fluorescent emission spectrum quenchable upon binding or release of glucose by the sugar-binding molecule;

exciting the first fluorophore with light of a wavelength sufficient to excite the fluorophore;

detecting at least one wavelength of light in the glucose-concentration-dependent optical signal from the fluorophore with a detector to produce a detected light signal; and

processing the detected light signal to produce a glucose concentration metric.

2. The method according to claim 1, further comprising displaying the glucose concentration metric on a display.

3. The method according to claim 1, wherein the glucose concentration metric is selected from the group consisting of a glucose concentration, a change in glucose concentration, a rate of change of glucose concentration, an amount of glucose, and combinations thereof.

4. The method according to claim 1, further comprising triggering an alarm when the glucose concentration metric is below a preset threshold.

5. The method according to claim 1, further comprising triggering an alarm when the glucose concentration metric is above a preset threshold.

6. The method according to claim 1, further comprising triggering an alarm when the glucose concentration metric is within a preset range.

7. The method according to claim 1, further comprising detecting at least one wavelength of light in an optical signal a second fluorophore in the glucose-sensing device, the second fluorophore comprising a fluorescein, a rhodamine, a cyanine, or fluorescent dye linked to the sugar-binding molecule or ligand to which the first fluorophore is not linked.

8. The method according to claim 7, further comprising:

processing the detected light signal from the second fluorophore; and

altering the glucose concentration metric based on the detected light signal from the second fluorophore.

9. The method according to claim 1, wherein the functionalized polymer or functionalized nano-particle ligand comprises a glycosylated dendrimer and contacting the implantable glucose-sensing device with a test sample under conditions that permit the sugar-binding molecule and the functionalized polymer or functionalized nano-particle ligand to interact in a glucose-concentration-dependent manner to produce a glucose-concentration-dependent optical signal comprises contacting under conditions that permit the sugar-binding molecule and the glycosylated dendrimer to interact.

10. The method according to claim 1, wherein the sugar binding molecule present and the functionalized polymer or functionalized nano-particle ligand are present throughout in pores of the hydrogel and contacting comprises contacting under conditions that permit the sugar-binding molecule and the functionalized polymer or functionalized nano-particle ligand to interact in the pores.

11. A method of measuring glucose concentration in a patient, said method comprising:

implanting an implantable glucose-concentration-sensing device in a patient;

contacting an implantable glucose-concentration-sensing device with a test sample under conditions that permit a sugar-binding molecule comprising Concanavalin A, other sugar-binding lectins, glucose binding protein, glucose oxidase, or glucose apo-oxidase, the sugar binding molecule present throughout a matrix of a hydrogel in the glucose-concentration-sensing device and a functionalized polymer or functionalized nano-particle ligand present throughout the matrix of the hydrogel in the glucose-sensing device to interact in a glucose-concentration-dependent manner to produce a glucose-concentration-dependent optical signal resulting from quenching of a first fluorophore comprising a fluorescein, a rhodamine, a cyanine, or fluorescent dye, the first fluorophore linked to the ligand or sugar-binding molecule and having a fluorescent emission spectrum quenchable upon binding or release of glucose by the sugar-binding molecule;

exciting the first fluorophore with light of a wavelength sufficient to excite the fluorophore;

detecting at least one wavelength of light in the glucose-dependent optical signal from the fluorophore with a detector to produce a detected light signal; and

processing the detected light signal to produce a glucose concentration metric reflective of the glucose concentration in the patient.

12. The method according to claim 11, further comprising displaying the glucose concentration metric on a display.

13. The method according to claim 11, wherein the glucose concentration metric is selected from the group consisting of a glucose concentration, a change in glucose concentration, a rate of change of glucose concentration, and combinations thereof.

14. The method according to claim 11, further comprising triggering an alarm when the glucose concentration metric is below a preset threshold.

15. The method according to claim 11, further comprising triggering an alarm when the glucose concentration metric is above a preset threshold.

16. The method according to claim 11, further comprising triggering an alarm when the glucose concentration metric is within a preset range.

17. The method according to claim 11, further comprising detecting at least one wavelength of light in an optical signal a second fluorophore in the glucose-sensing device, the second fluorophore comprising a fluorescein, a rhodamine, a cyanine, or fluorescent dye linked to the sugar-binding molecule or ligand to which the first fluorophore is not linked.

18. The method according to claim 17, further comprising:

processing the detected light signal from the second fluorophore; and

altering the glucose concentration metric based on the detected light signal from the second fluorophore.

19. The method according to claim 11, further comprising placing a housing containing at least the glucose-concentration-sensing device on the patient.

20. The method according to claim 19, wherein placing the housing on the patient comprises placing the housing on skin of the patient.

21. The method according to claim 11, wherein implanting comprises implanting the glucose-concentration-sensing device under the dermis of the patient.

22. The method according to claim 11, wherein implanting comprises needle injection, air jet injection, or a surgical procedure.

23. The method according to claim 11, wherein the functionalized polymer or functionalized nano-particle ligand comprises a glycosylated dendrimer and contacting the implantable glucose-concentration-sensing device with a test sample under conditions that permit the sugar-binding molecule and the functionalized polymer or functionalized nano-particle ligand to interact in a glucose-concentration-dependent manner to produce a glucose-concentration-dependent optical signal comprises contacting under conditions that permit the sugar-binding molecule and the glycosylated dendrimer to interact.

24. The method according to claim 11, wherein the sugar binding molecule present and the functionalized polymer or functionalized nano-particle ligand are present throughout in pores of the hydrogel and contacting comprises contacting under conditions that permit the sugar-binding molecule and the functionalized polymer or functionalized nano-particle ligand to interact in the pores.