OVULATION MONITORING PLATFORM

Abstract

Provided herein are devices and methods for monitoring biofluids related to ovulation. Such devices include the use of electrochemical aptamer-based (EAB) sensors.

Claims

1. A device for measuring one or more analytes in a sample of interstitial fluid, blood or both, comprising; at least one electrochemical aptamer-based (EAB) sensor comprising one or more attached redox couples that measure at least one of said analytes, wherein the at least one EAB sensor is positioned ex-vivo; and a means to establish fluid communication between the at least one EAB sensor and the sample of interstitial fluid, blood or both; wherein the one or more analytes are selected from the group consisting of follicle stimulating hormone, thyroid stimulating hormone, luteinizing hormone (LH), anti-müllerian hormone, prolactin, estrogen, progesterone, and testosterone, or a metabolite thereof, or any combination of the foregoing.

2. The device of claim 1, wherein the means to establish fluid communication is at least one needle.

3. The device of claim 2, wherein the at least one needle is hollow and it establishes fluid communication of the sample of interstitial fluid or blood to the at least one sensor by diffusion.

4. The device of claim 2, wherein the at least one needle is hollow and it establishes fluid communication of the sample of interstitial fluid or blood to the at least one sensor by advection.

5. The device of claim 1, wherein the device is capable of continuous measurement of one or more analytes for at least 6 hours, or at least 24 hours.

6. The device of claim 1, wherein the device is capable of continuous measurement of one or more analytes for at least 1 week, or at least 2 weeks.

7. The device of claim 1, wherein the device is capable of taking a single measurement.

8. The device of claim 1, comprising a first EAB sensor and a second EAB sensor, wherein the first EAB sensor measures LH and the second EAB sensor measures progesterone or a metabolite thereof.

9. A method of predicting and/or confirming ovulation of a subject using a device of claim 1, the method comprising; measuring one or more analytes from interstitial fluid, blood or both of the subject; and measuring a concentration change of luteinizing hormone (LH), or progesterone or a metabolite thereof, or any combination thereof in the subject, wherein the one or more analytes are selected from the group consisting of progesterone, luteinizing hormone (LH), estrogen, follicle stimulating hormone (FSH), their metabolites, and any combinations thereof.

10. The method of claim 9, further comprising using at least two urine-based LH test strips to indicate a time for use of the device, and wherein said device continuously measures at least LH for at least 6 hours.

11. The method of claim 10, wherein said device continuously measures at least LH for at least 24 hours.

12. The method of claim 9, further comprising taking at least one measurement of progesterone by a device containing a sensor for progesterone.

13. The method of claim 9, wherein the device contains sensors for both LH and progesterone, and measures them both continuously for at least 6 hours.

14. The method of claim 9, wherein the device provides data selected from the group consisting of continuous concentration data of at least one of said analytes, a predicted time of ovulation, a predicted time of peak fertility, and a confirmation that ovulation has occurred, or any combination thereof.

15. A method for predicting ovulation in a subject using a device of claim 1, the method comprising: determining a baseline luteinizing hormone level in the subject prior to ovulation by continuous monitoring average luteinizing hormone levels over an initial time period of at least 10 minutes, wherein the initial time period is cycle start date until 18 days before the next expected cycle start date; and predicting ovulation when the luteinizing hormone levels: a) increase at least 2-fold over the baseline luteinizing hormone level; and/or b) reach an absolute luteinizing hormone level of greater than 20 mUl/ml.

16. The method of claim 15, wherein ovulation is predicted when the luteinizing hormone levels increase 2-fold or 3-fold over the baseline luteinizing hormone level.

17. A method of confirming ovulation in a subject using a device of claim 1, the method comprising: determining a baseline of progesterone level, or a level of metabolites thereof, in the subject prior to ovulation by continuous monitoring average progesterone levels, or average levels of metabolites thereof, over an initial time period of at least 10 minutes, wherein the initial time period is cycle start date until 18 days before the next expected cycle start date; and confirming ovulation when progesterone levels, or levels of metabolites thereof: a) increase at least 2-fold over the baseline of progesterone level, or a level of metabolites thereof, and/or b) reach an absolute progesterone level, or level of metabolites thereof, of greater than 5 ng/ml progesterone or a metabolite thereof.

18. The method of claim 17, wherein ovulation is predicted when the progesterone levels, or levels of metabolites thereof, increase 2-fold or 3-fold over the baseline progesterone level, or level of metabolites thereof.

19. The method of claim 17, wherein the metabolite of progesterone is pregnanediol.

20. The method of claim 15, wherein the initial time period is at least 2 hours, or about 2 hours.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The objects and advantages of the disclosed invention will be further appreciated in light of the following detailed descriptions and drawings in which:

[0014] FIG. 1A is a representation of an aptamer sensing element.

[0015] FIG. 1B is a representation of an aptamer sensing element.

[0016] FIG. 2A is a cross-sectional view of a device according to an embodiment of the disclosed invention.

[0017] FIG. 2B is a cross-sectional view of a device according to another embodiment of the disclosed invention.

[0018] FIG. 3 is a graph showing an example plot of hormone levels during a subject's ovulation cycle.

DEFINITIONS

[0019] While the following terms are believed to be well understood by one of ordinary skill in the art, definitions are set forth to facilitate explanation of the disclosed subject matter. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed subject matter belongs.

[0020] As used herein, the term “about,” when referring to a value or to an amount of mass, weight, time, volume, pH, size, concentration or percentage is meant to encompass variations of in some embodiments ±20%, in some embodiments ±10%, in some embodiments ±5%, in some embodiments ±1%, in some embodiments ±0.5%, and in some embodiments ±0.1% from the specified amount, as such variations are appropriate to perform the disclosed method.

[0021] As used herein, the term “analyte” means an oligonucleotide or polynucleotide having a sequence to which a particular electrode-bound oligonucleoride is designed to hybridize. It can also refer to a small molecule of the like to which a particular aptamer is designed to hybridize.

[0022] As used herein, the term “aptamer” means any polynucleotide molecule (for example, DNA or RNA molecule containing natural or synthetic nucleotides) that has the ability to bind other molecules. For example, aptamers have been selected which bind nucleic acids, proteins, small organic components and even entire organisms. Examples of aptamers include SEQ ID NOs: 1-8.

[0023] The particular use of terms “oligonucleotide” and “polynucleotide” should in no way be considered limiting. “Oligonucleotide” is used when the relevant nucleic acid molecules typically comprise less than about 100 bases. “Polynucleotide” is used when the relevant nucleic acid molecules typically comprise more than about 100 bases. Both terms are used to denote DNA, RNA, modified or synthetic DNA or RNA (including but not limited to nucleic acids comprising synthetic and naturally-occurring base analogs, dideoxy or other sugars, and thiols), and PNA or other nucleobase containing polymers. However, probes and/or targets may comprise fewer than or more than 100 bases (inclusive). Accordingly, the terms “oligonucleotide” and “polynucleotide” are used to describe particular embodiments of the invention. The terms in no way define or limit the length of the nucleic acids that may be used to practice the invention.

[0024] As used herein, “biofluid” may mean any human biofluid, including, without limitation, sweat, interstitial fluid, blood, plasma, serum, tears, and saliva.

[0025] As used herein, “continuous sensing” with a “continuous sensor” means a sensor that reversibly changes in response to concentration of an analyte, where the only requirement to increase or decrease the signal of the sensor is to change the concentration of the analyte in the biofluid. Such a sensor, therefore, does not require regeneration of the sensor by locally changing pH, for example. Similarly, as used herein, “continuous monitoring or measurement or sensing” means the capability of a device to provide multiple measurements of an analyte over time.

[0026] “EAB sensor” means an electrochemical aptamer-based biosensor that is configured with multiple aptamer sensing elements that, in the presence of a target analyte in a fluid sample, produce a signal indicating analyte capture, and which signal can be added to the signals of other such sensing elements, so that a signal threshold may be reached that indicates the presence or concentration of the target analyte. As non-limiting examples, such sensors can be in the forms disclosed in U.S. Pat. Nos. 7,803,542 and 8,003,374.

[0027] As used herein, “fluid communication” means that fluid can flow from one component to another; such flow may be by way of one or more intermediate (and not specifically mentioned) other components; and such may or may not be selectively interrupted (e.g., with a valve).

[0028] As used herein, the expression “interstitial fluid” means the substantially clear, substantially colorless fluid found in the human body, which occupies the space between the cells of the human body.

[0029] “Measured” can imply an exact or precise quantitative measurement and can include broader meanings such as, for example, measuring a relative amount of change of something. Measured can also imply a binary or qualitative measurement, such as ‘yes’ or ‘no’ type measurements.

[0030] The “subject” herein is, in some embodiments, a human and female. In some variations, the subject is an adult.

[0031] It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

DETAILED DESCRIPTION

[0032] The details of one or more embodiments of the disclosed subject matter are set forth in this document. Modifications to embodiments described in this document, and other embodiments, will be evident to those of ordinary skill in the art after a study of the information provided herein.

[0033] The present disclosure may be understood more readily by reference to the following detailed description of the embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this application is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting. Also, in some embodiments, as used in the specification and including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.

[0034] The present invention involves novel devices and methods for monitoring biofluids related to ovulation. In one embodiment, the device of the present invention uses a needle or microneedles connected to one or more EAB sensors to monitor biofluid analytes related to ovulation. The one or more EAB sensors are connected in a way such that when the needle or microneedles are intradermally inserted into the subject, the EAB sensors are positioned outside of the body and on a separate structure distal to the needle or microneedles inserted into the dermis. For example, with reference to FIGS. 2A and 2B, elements 210, 220 and 250 shows the sensor is completely outside of the body, there is a gap 230 and microneedles 212 and 232 that penetrate the dermal layer (12). As such, the one or more EAB sensors are configured to monitor biofluid analytes ex-vivo.

[0035] Such analytes may include follicle stimulating hormone, thyroid stimulating hormone, luteinizing hormone (LH), human chorionic gonadotropin, anti-müllerian hormone, prolactin, estrogen, progesterone, and testosterone, or any metabolites thereof, or any combinations of the foregoing. In some variations, the analytes include progesterone, luteinizing hormone (LH), estrogen, and follicle stimulating hormone (FSH), or any metabolites thereof, or any combinations of the foregoing. In one embodiment, the device of the present invention is capable of continuous sensing of these analytes over a certain period of time. Some embodiments of the disclosed invention are directed to continuous aptamer-based sensors for LH or progesterone in interstitial fluid or other biofluids.

[0036] In some embodiments of the device of the present invention, electrochemical aptamer-based (EAB) sensors are used. With reference to FIG. 1A, an aptamer sensing element is depicted. While the figure depicts, and the discussion focuses on, a single aptamer sensing element, EAB sensors described herein will include a large number (thousands, millions, or billions of individual sensing elements, having an upper limit of 1014/cm.sup.2) attached to the electrode. The aptamer sensing element 110 includes an analyte capture complex 112, which in turn is comprised of a randomized aptamer sequence 140 that is selected to interact with a target analyte molecule 160, and one or more linker nucleotide sections 142 (one is depicted). The analyte capture complex 112 has a first end covalently bonded to a sulfur molecule, e.g., a thiol 120, which is in turn covalently bonded to an electrode base 130. The electrode 130 may be comprised of gold or another suitable conductive material. The sensing element further includes a redox moiety 150 that may be covalently bonded to a second end of the analyte capture complex 112 or bound to it by a linking section. In the absence of the target analyte, the aptamer 140 is in a first configuration, and the redox moiety 150 is in a first position relative to the electrode 130. When the device interrogates the sensing element using, e.g., square wave voltammetry (SWV), the sensing element produces a first electrical signal, eTA.

[0037] With reference to FIG. 1B, the aptamer 140 is selected to specifically interact with a target analyte 160, so that when the aptamer interacts with a target analyte molecule, the aptamer undergoes a conformation change that partially disrupts the first configuration and forms a second configuration. The capture of the target analyte 160 accordingly moves the redox moiety 150 into a second position relative to the electrode 130. Now when the biofluid sensing device interrogates the sensing element, the sensing element produces a second electrical signal, eTB that is distinguishable from the first electrical signal. After a recovery interval, the aptamer releases the target analyte, and the aptamer will return to the first configuration, which will produce the corresponding first electrical signal when the sensing element is interrogated.

[0038] Certain embodiments of the disclosed invention show sensors as simple individual elements. It is understood that many sensors require two or more electrodes, reference electrodes, or additional supporting technology or features which are not captured in the description herein. Sensors measure a characteristic of an analyte. Sensors are preferably electrical in nature, but may also include optical, chemical, mechanical, or other known biosensing mechanisms. Sensors can be in duplicate, triplicate, or more, to provide improved data and readings. Sensors may provide continuous or discrete data and/or readings. Certain embodiments of the disclosed invention show sub-components of what would be sensing devices with more sub-components needed for use of the device in various applications, which are known (e.g., a battery, antenna, adhesive), and for purposes of brevity and focus on inventive aspects, such components may not be explicitly shown in the diagrams or described in the embodiments of the disclosed invention.

[0039] The present invention includes a means to establish fluid communication between the sensor(s) and the sample of interstitial fluid, blood or both. In many embodiments, the means will involve penetrating the dermis to access biofluids such as interstitial fluid and blood. In one embodiment, the means of establishing fluid communication uses a single needle. In another embodiment, the means of establishing fluid communication uses a multitude of microneedles.

[0040] With reference to FIG. 2A, in an embodiment of the disclosed invention, a device 200 is placed partially in-vivo into the skin 12 comprised of the epidermis 12a, dermis 12b, and the subcutaneous or hypodermis 12c. A portion of the device 200 accesses fluids such as interstitial fluid from the dermis 12b and/or blood from a capillary 12d. Access is provided, for example, by microneedles 212 formed of metal, polymer, semiconductor, glass or other suitable material, and may include a hollow lumen 232 that contributes to a sample volume. Sample volume is also contributed to by volume 230 above material from which the microneedles 212 project yet below sensor probes 220 on electrode 250 on a polymer substrate 210. Together, probes 220 and electrode 250 form a sensor 220, 250. Together the volume of volume 230 and lumen 232 form a sample volume and can be a microfluidic component such as channels, a hydrogel, or other suitable material. A diffusion and/or advective flow pathway exists from the invasive biofluid such as interstitial fluid or blood to the sensor probes 220, the pathway beginning at location 290 at the inlet to the microneedle 212, first reaching the sensor probes 220. Alternative arrangements and materials are possible, such as using a single needle, hydrogel polymer microneedles, or other suitable means to couple an invasive fluid to one or more sensors, although these alternative arrangements and materials are not explicitly shown in the figures. In addition, one or more of the features of device 200 or the entire device 200 may be implanted into the body and perform similarly as described herein.

[0041] With further reference to FIG. 2A, sensor probes 220 are affinity-based and, in one embodiment, comprise aptamer sequences (such as any one or more of SEQ ID NOs 1-8) that are selective in reversible binding to an analyte and permanently thiol bonded to the electrode 250 and used to sense an analyte such as glucose or other analyte by means of electrochemical detection. In some embodiments, the electrode 250 includes gold. In some embodiments, probes are electrical in nature and utilize an attached redox couple to transduce the electrochemical signal or instead measure change in impedance between the electrode and solution. In other embodiments, probes are optical in nature, such as fluorescently labeled aptamers that are labeled with a quencher (i.e. molecular beacon) that may not require electrode 250 but may use optical sensors and light sources to detect analyte aptamer interactions. Such alternative arrangements are not explicitly shown in the figures.

[0042] With reference to FIG. 2B, where like numerals refer to like features, a plurality of sensors for a plurality of analytes are provided. In one embodiment, sensor 250a and sensor 220a detect LH, while sensor 250b and sensor 220b detect progesterone. This figure shows that a device may have one or more sensors for one or more analytes.

[0043] With reference to FIG. 3, an example plot 300 of hormone levels during a woman's ovulation cycle is shown with plot line 380 indicating levels of follicle stimulating hormone (FSH), plot line 382 indicating levels of estrogen, plot line 384 indicating levels of LH, and plot line 386 indicating levels of progesterone. Section 390 indicates baseline levels of hormones at the start of the cycle. Measuring one or more of these hormones in the first 4 days of the menstrual cycle can determine baseline levels, ovarian reserve, and hormone imbalance that could lead to subfertility (e.g., decreased fertility potential). Section 392 indicates the fertile window. Measuring estrogen or its metabolites, LH, and/or progesterone (or its metabolites) can determine the fertile days of the cycle. An increase in estrogen singles the start of fertile window, surge in LH indicates 2-3 most fertile days of the cycle and increase in progesterone confirms ovulation has occurred and section 394 indicates the luteal phase of the cycle. This is the last days of the cycle (typically 10-14 days) which progesterone is produced at high levels to confirm ovulation has occurred. The devices of the present invention may be continuous or for measuring a single concentration of the analyte or analytes. In one embodiment, the devices of the present invention comprise at least one aptamer sensor and at least one needle which couples the aptamer sensor to a biofluid such as interstitial fluid. The present invention may be used to measure any of these analytes and/or their metabolites as well. Several methods of testing are now described, which are superior to current once-a-day urine testing methods.

[0044] With reference to embodiments of the present invention, in a first method testing scenario, a urine based LH strip is used at least twice prior to the expected LH peak. When the LH test strips indicate an increase in LH (surge), which requires at least two such tests, at least one device of the present invention is applied to the skin to measure LH continuously for at least one of 6 hours, 12 hours, 24 hours, 2 days, 3 days, or 6 days.

[0045] With reference to embodiments of the present invention, a second method testing scenario further includes using the device of the present invention to measure progesterone. This measure would be for at least one of 6 hours, 12 hours, 24 hours, 2 days, 3 days, or 6 days. The second method may be performed after the first method with a distinct device and sensor, or it may be performed with the same device used in the first method by the device containing sensors for both LH and progesterone.

[0046] With reference to embodiments of the present invention, in a third method, one or more devices measure one or more analytes of FSH, LH, progesterone, or estrogen, or their metabolites, for at least one of 6 hours, 12 hours, 24 hours, 2 days, 3 days, 6 days, 2 weeks, or 4 weeks.

[0047] In yet other embodiments, provided is a method for predicting ovulation in a subject using any of the devices described herein that incorporate EAB sensor(s) positioned ex-vivo. In some variations, the method comprises: determining a baseline luteinizing hormone level in the subject prior to ovulation by monitoring average luteinizing hormone levels over an initial time period of at least 10 minutes, wherein the initial time period is cycle start date until 18 days before the next expected cycle start date; and predicting ovulation when the luteinizing hormone levels: a) increase at least 2-fold over the baseline luteinizing hormone level; and/or b) reach an absolute luteinizing hormone level of greater than 20 mUI/ml.

[0048] In other variations, the method comprises: determining a baseline of progesterone level, or a level of metabolites thereof, in the subject prior to ovulation by monitoring average progesterone levels, or average levels of metabolites thereof, over an initial time period of at least 10 minutes, wherein the initial time period is cycle start date until 18 days before the next expected cycle start date; and confirming ovulation when progesterone levels, or levels of metabolites thereof: a) increase at least 2-fold over the baseline of progesterone level, or a level of metabolites thereof, and/or b) reach an absolute progesterone level, or level of metabolites thereof, of greater than 5 ng/ml progesterone or a metabolite thereof. In one variation, the metabolite of progesterone is pregnanediol.

[0049] In one embodiment, the device of the present invention is single use. In another embodiment, the device is pre-wetted with fluid (such as buffer fluid) in spaces 230, 232. The analytes are coupled to the sensors by diffusion. In an alternative embodiment, the device is dry and fluid flows into spaces 230, 232 by positive pressure of interstitial fluid as the device is pressed against skin or by capillary action that pulls interstitial fluid and/or blood into the device spaces 230, 232.

[0050] In one embodiment, the device the present invention reports continuous concentration data for one or more analytes to the user. For example, information may be reported through a wirelessly connected smart phone that displays one or more plots of analyte concentration like that shown in FIG. 3. In another embodiment, the present invention reports to the user simple single data point data such as predicted time of ovulation, predicted time of peak fertility both based on LH, and/or a simple yes/no answer of did the user ovulate based on progesterone measurements.

[0051] Although not described in detail herein, other steps which are readily interpreted from or incorporated along with the disclosed embodiments shall be included as part of the invention. The embodiments that have been described herein provide specific examples to portray inventive elements, but will not necessarily cover all possible embodiments commonly known to those skilled in the art.

[0052] All documents cited are incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.

[0053] It is to be further understood that where descriptions of various embodiments use the term “comprising,” and/or “including” those skilled in the art would understand that in some specific instances, an embodiment can be alternatively described using language “consisting essentially of” or “consisting of.”

[0054] While particular embodiments of the present invention have been illustrated and described, it would be obvious to one skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.