Methods for reversible male birth control

Abstract

Disclosed herein are contraceptives and methods for reversible male birth control. A method (1100) includes providing (1102) a polymer (202) including a viscosity and reducing (1104) the viscosity of the polymer (202) to produce a polymer solution (200). The method (1100) further includes injecting (1106) the polymer solution (200) into the seminiferous duct (30) of a male subject while reducing the viscosity of the polymer (202). The polymer solution (200) forms a polymer barrier (10) in the seminiferous duct (30) to physically block the outflow of sperm in the seminiferous duct after injection.

Description

[0001] Citation of Related Applications

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 336,219, filed on April 28, 2022, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The presently disclosed subject matter relates to contraceptives and, more particularly, to methods for reversible male birth control. Background Art

[0004] Women typically bear most of the economic and health-related burdens of unwanted pregnancies and / or bear all of the economic and / or health-related burdens of contraceptives. Long-term reversible contraceptives (such as intrauterine devices (IUDs) and implantable sustained-release birth control drugs) have become popular birth control methods among women. Comparable male contraceptive methods do not exist, which affects pregnancy rates worldwide. Summary of the invention

[0005] The subject matter of the present disclosure provides examples of methods for male birth control. It is desirable to develop improved methods and / or methods for male birth control using polymers that can provide contraceptives for male subjects (e.g., male humans, non-fertile humans, male animals, non-fertile animals, etc.). It is also desirable to provide contraceptives and / or reversible male birth control methods for male subjects. Therefore, the subject matter of the present application is developed in response to the current state of the art, and in particular in response to the desire to provide contraceptives and / or methods for reversible male birth control for male subjects.

[0006] Disclosed herein is a method for male birth control. A method includes providing a polymer including a viscosity, reducing the viscosity of the polymer to produce a polymer solution, and injecting the polymer solution into a subject's vas deferens while reducing the viscosity of the polymer to form a polymer barrier against sperm in the vas deferens after injection. The foregoing subject matter of this paragraph characterizes Example 1 of the present disclosure.

[0007] Providing the polymer includes providing a biocompatible polymer.The foregoing subject matter of this paragraph characterizes Example 2 of the present disclosure, wherein Example 2 also includes subject matter according to Example 1 above.

[0008] Providing the biocompatible polymer includes providing a polysaccharide.The foregoing subject matter of this paragraph characterizes Example 3 of the present disclosure, wherein Example 3 also includes subject matter according to any one of Examples 1 or 2 above.

[0009] Providing the polysaccharide includes providing alginate.The foregoing subject matter of this paragraph characterizes Example 4 of the present disclosure, wherein Example 4 also includes subject matter according to any one of Examples 1, 2, or 3 above.

[0010] Providing the alginate comprises providing sodium alginate.The foregoing subject matter of this paragraph characterizes Example 5 of the present disclosure, wherein Example 5 further comprises subject matter according to any one of Examples 1, 2, 3 or 4 above.

[0011] Reducing the viscosity of the polymer includes reducing the viscosity of the polymer to allow the polymer solution to be dispensed via a small gauge hypodermic needle.The foregoing subject matter of this paragraph characterizes Example 6 of the present disclosure, wherein Example 6 also includes subject matter according to Example 1 above.

[0012] The small gauge hypodermic needle includes a hypodermic needle with a gauge less than or equal to 27 gauge. The foregoing subject matter of this paragraph characterizes Example 7 of the present disclosure, wherein Example 7 also includes subject matter according to any one of Examples 1 and 6 above.

[0013] Injecting the polymer solution includes injecting the polymer solution into the vas deferens of the subject using the small gauge hypodermic needle while reducing the viscosity of the polymer. The foregoing subject matter of this paragraph characterizes Example 8 of the present disclosure, wherein Example 8 also includes subject matter according to any one of Examples 1, 6, and 7 above.

[0014] Reducing the viscosity of the polymer includes temporarily reducing the viscosity of the polymer.The foregoing subject matter of this paragraph characterizes Example 9 of the present disclosure, wherein Example 9 also includes subject matter according to Example 1 above.

[0015] Temporarily reducing the viscosity of the polymer includes mixing the polymer with glucono-delta-lactone (GdL) to produce the polymer solution.The foregoing subject matter of this paragraph characterizes Example 10 of the present disclosure, wherein Example 10 also includes subject matter according to any of Examples 1 and 9 above.

[0016] The polymer solution forms the polymer barrier to sperm in response to being present in the vas deferens for a predetermined amount of time, and the predetermined amount of time is the amount of time for the subject to metabolize the GdL. The foregoing subject matter of this paragraph characterizes Example 11 of the present disclosure, wherein Example 11 also includes subject matter according to any of Examples 1, 9, and 10 above.

[0017] The polymer solution forms the polymer barrier to sperm for the amount of time the subject metabolizes the polymer.The foregoing subject matter of this paragraph characterizes Example 12 of the present disclosure, wherein Example 12 also includes subject matter according to Example 1 above.

[0018] The amount of time is at least one year. The foregoing subject matter of this paragraph characterizes Example 13 of the present disclosure, wherein Example 13 also includes subject matter according to Example 1 above.

[0019] The method further comprises injecting a calcium chelator into the vas deferens to degrade the polymer barrier.The foregoing subject matter of this paragraph characterizes Example 14 of the present disclosure, wherein Example 14 further comprises subject matter according to Example 1 above.

[0020] Injecting the calcium chelator into the vas deferens comprises injecting ethylenediaminetetraacetic acid (EDTA) into the vas deferens.The foregoing subject matter of this paragraph characterizes Example 15 of the present disclosure, wherein Example 14 also comprises subject matter according to any of Examples 1 and 14 above.

[0021] Injecting the EDTA into the vas deferens comprises injecting the EDTA into the vas deferens via a hypodermic needle comprising less than or equal to 27 gauge. The foregoing subject matter of this paragraph characterizes Example 16 of the present disclosure, wherein Example 16 also comprises subject matter according to any of Examples 1, 14, and 15 above.

[0022] Another method for male birth control is also disclosed herein. The method includes positioning a polymer barrier against sperm into the vas deferens of a subject, and injecting a calcium chelator into the vas deferens to degrade the polymer barrier. The foregoing subject matter of this paragraph characterizes Example 17 of the present disclosure.

[0023] The calcium chelator includes ethylenediaminetetraacetic acid (EDTA).The foregoing subject matter of this paragraph characterizes Example 18 of the present disclosure, wherein Example 18 also includes subject matter according to Example 17 above.

[0024] Additionally, another method for male birth control is disclosed herein. The method includes reducing the viscosity of a polymer to produce a polymer solution, injecting the polymer solution into the vas deferens of a subject while reducing the viscosity of the polymer to produce a polymer barrier for sperm in the vas deferens after the viscosity of the polymer increases while present in the vas deferens, positioning the polymer barrier in the vas deferens, and injecting a calcium chelator into the vas deferens to degrade the polymer barrier. The foregoing subject matter of this paragraph characterizes Example 19 of the present disclosure.

[0025] The polymer includes sodium alginate, and the calcium chelator includes ethylenediaminetetraacetic acid (EDTA).The foregoing subject matter of this paragraph characterizes Example 20 of the present disclosure, wherein Example 20 also includes subject matter according to Example 19 above. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] A more particular description of the embodiments briefly described above will be presented with reference to specific embodiments illustrated in the accompanying drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0027] FIG. 1 is a schematic diagram of a polymer barrier against sperm in the vas deferens of a male subject in the prior art;

[0028] Figure 2 is a schematic diagram of one embodiment of a polymer solution that may be inserted into the vas deferens of a male subject via a small gauge needle to form the polymer barrier shown in FIG. 1 ;

[0029] Figure 3 is a schematic diagram of one embodiment of a calcium chelator that can degrade the polymer barrier shown in FIG. 1 ;

[0030] Figure 4 is a schematic diagram of one embodiment of a polymer barrier against sperm comprising a spermicide;

[0031] Figure 5 is a schematic diagram of one embodiment of a polymer solution comprising a polymer and a spermicide that can be inserted into the vas deferens of a male subject to form Figure 4 polymer barrier;

[0032] Figure 6 It shows that the Figure 4 A schematic diagram of one embodiment of particles containing a spermicide in a polymer barrier;

[0033] Figure 7 It shows Figure 6 A schematic diagram of one embodiment of a particle showing a plurality of holes for encapsulating a spermicide;

[0034] Figure 8 is a schematic diagram of another embodiment of a polymer solution containing a spermicide that can be inserted into the vas deferens of a male subject to form Figure 4 a polymer barrier containing a spermicide;

[0035] Fig. 9 Yes, it can Figure 4 A schematic diagram of an embodiment of a polymer barrier degrading calcium chelator;

[0036] Fig. 10A and 10B It shows Figure 4 A graph of the concentration of an embodiment of a spermicide contained in a polymer barrier over about one year; and

[0037] Figures 11 to 20 is a schematic flow chart of various methods of reversible male birth control. DETAILED DESCRIPTION

[0038] Various embodiments disclosed herein provide reversible methods of reversible birth control for male subjects (eg, male humans, non-reproductive humans, male animals, etc.). Also disclosed herein are reversible contraceptives for male subjects.

[0039] Various embodiments disclosed herein provide, among other things, barriers (or implants) that provide a less invasive, long-term male contraceptive. The barrier is injected or otherwise placed into the vas deferens of a male subject (e.g., a male human, a non-fertile human, a male animal, a non-fertile animal, etc.) to block the outflow of sperm. Other embodiments provide barriers comprising spermicides that can provide two barrier defenses - physical blockage and chemical defense.

[0040] The barrier may include a polymer or polymer matrix that blocks the vas deferens and, in some embodiments, may further support a sperm inhibitor as a secondary defense. The polymer may be a biocompatible polymer, such as a polysaccharide (e.g., an alginate (e.g., sodium alginate)). The barrier blocks or at least partially blocks the vas deferens and, in some embodiments, may provide a sperm inhibitor nearly halfway to incapacitate (e.g., kill sperm) sperm that pass through the barrier. In certain embodiments, the sperm inhibitor includes a calcium blocker sperm inhibitor encapsulated in microparticles that are suspended in a semi-porous hydrogel polymer.

[0041] Objectives of various embodiments may include, but are not limited to, providing reversible male contraception, providing a male contraceptive that does not completely occlude the vas deferens, providing a male contraceptive that partially occludes the vas deferens with a spermicide, providing a microparticle polymer plug for male contraception, providing male contraception via a minimally invasive outpatient procedure, providing cost-effective reversible male contraception, providing a male contraceptive with improved reversal rates, providing a male contraceptive that does not contain hormones, a male contraceptive that has an effective life span of at least one year, providing a male contraceptive that employs partial occlusion that avoids granulomas of the vas deferens, providing a male contraceptive with multiple lines of action (e.g., a semi-permeable barrier and a spermicide), providing a spermicide that is soluble in an organic solvent or diluent, providing a spermicide implant that degrades predictably in the body over time, providing a barrier that acts as both a physical occlusion and a chemical / drug delivery device, providing a polymer that can be injected into the vas deferens with a 27 gauge needle or smaller, providing a barrier that does not harm the vas deferens, and providing a spermicide-containing barrier that does not harm the vas deferens. The above and other objects can be achieved using a barrier that at least partially blocks / occludes the vas deferens, and can further include a sperm inhibitor for incapacitating sperm not occluded / blocked by the barrier. The barrier can include a scaffold to secure the position of the barrier in the vas deferens.

[0042] 1 is a schematic diagram of a prior art polymeric barrier 10 for occluding and / or blocking the outflow of sperm 20 in a male subject's vas deferens 30. The polymeric barrier 10 is typically injected into the vas deferens 30 using a hypodermic needle.

[0043] Modern polymers that form polymer barrier 10 typically include a relatively high viscosity. Typically, a 25 gauge or larger hypodermic needle is required to inject modern polymers into vas deferens 30 to form polymer barrier 10.

[0044] Large hypodermic needles (e.g., 25 gauge and larger) typically require a relatively large incision to be made in the scrotum of a male subject to access the vas deferens 30. In addition, 25 gauge and larger hypodermic needles are typically used to inject vas into the scrotum of a male subject. Specification And larger gauge hypodermic needles may leave a relatively large puncture hole in the vas deferens 30, which may make the subject more susceptible to infection, make the subject more susceptible to damage from granulomas caused by sperm 20 leaking from the vas deferens 30, require sutures to close and / or take longer to heal than smaller gauge hypodermic needles.

[0045] Figure 2 is a schematic diagram of one embodiment of a polymer solution 200 that can form a polymer barrier 10 (see FIG. 1 ) to block sperm 20 in a male subject's vas deferens 30. In various embodiments, a first portion of the polymer solution 200 includes a polymer 202 (e.g., a liquid and / or liquefiable polymer), and a second portion of the polymer solution 200 includes a diluent 204.

[0046] The polymer 202 may include any one or more suitable polymers known or developed in the future that can be inserted into the vas deferens 30 of a male subject and form a polymer barrier 10 to block the outflow of sperm 20. The polymer 202 may include liquid and / or solid chemical states. In various embodiments, the polymer 202 includes, among other possible suitable polymers and / or substances, hydrogels, starches, algae (e.g., brown algae), collagen, gelatin, fibrin, etc., each of which is contemplated herein. In certain embodiments, the polymer 202 includes natural polymer materials and / or substances.

[0047] In various embodiments, the polymer 202 is biocompatible. In some embodiments, the biocompatible polymer 202 includes a polysaccharide, which may include any suitable polysaccharide. The polysaccharide may include a carbohydrate formed from a plurality of sugar units (e.g., ten or more monosaccharides), wherein the carbohydrate includes carbon (C), hydrogen (H), and oxygen (O) in a 1:2:1 ratio.

[0048] In certain embodiments, the polysaccharide comprises alginate, which may comprise any suitable alginate. Alginate comprises β-d-mannuronic acid and α-L-guluronic acid arranged in homogeneous (e.g., MM or GG) and heterogeneous (e.g., MG or GM) blocks, in a pyranose conformation (1,4) connection. In one embodiment, alginate particularly comprises sodium alginate (NaC6H7O6) in addition to possible and suitable alginate contemplated herein.

[0049] In various embodiments, polymer 202 includes any one or more polymer substances and / or polymer types that include a viscosity that is capable of temporarily decreasing. In additional or alternative embodiments, polymer 202 includes any one or more polymer substances and / or polymer types that include a viscosity that is capable of temporarily decreasing and then increasing. Thus, each of these polymers 202 can be considered a gelling polymer 202.

[0050] The diluent 204 may include any one or more suitable substances capable of temporarily reducing the viscosity of the polymer 202 contained in the polymer solution 200. In various embodiments, the diluent 204 may temporarily reduce the viscosity of the polymer 202 so that the polymer solution 200 may be injected into the vas deferens 30 using a 27 gauge or smaller hypodermic needle. In addition, the diluent 204 may include any one or more suitable substances capable of being metabolized by the male subject such that the viscosity of the polymer 202 increases to form the polymer barrier 10 in the vas deferens. In certain embodiments, the diluent 204 may include, in addition to possible diluents, glucono-delta-lactone (GdL), also known as gluconolactone (C6H 10 06), each of which is contemplated herein. In additional or alternative embodiments, the diluent 204 includes calcium chloride, phosphates, lactates, acetates, aluminum, calcium compounds, barium compounds, and / or the like.

[0051] The diluent 204 used to produce the polymer solution 200 can depend on the polymer 202 used to form the polymer barrier 10. Similarly, the type of diluent 204 used in the polymer solution 200 can depend on the type of polymer 202 used to form the polymer barrier 10. Furthermore, the diluent 204 and / or the type of diluent 204 used in the polymer solution 200 can depend on the polymer 202 and / or the type of polymer 202 used to form the polymer barrier 10.

[0052] The ratio of polymer 202 to diluent 204 in polymer solution 200 may include any suitable ratio that allows diluent 204 to temporarily reduce the viscosity of polymer 202 so that polymer solution 200 can be injected into vas deferens 30 using a 27 gauge or smaller needle. Additionally or alternatively, the ratio of polymer 202 to diluent 204 in polymer solution 200 may include any suitable ratio that allows diluent 204 to be metabolized in vas deferens 30 so that the temporarily reduced viscosity of polymer 202 can be increased in vas deferens 30 in response to the male subject metabolizing diluent 204 to form polymer barrier 10 in vas deferens 30.

[0053] The ratio of polymer 202 to diluent 204 used in polymer solution 200 can depend on the polymer 202 used to form polymer barrier 10. Similarly, the ratio of polymer 202 to diluent 204 used in polymer solution 200 can depend on the type of polymer 202 used to form polymer barrier 10. Furthermore, the ratio of polymer 202 to diluent 204 used in polymer solution 200 can depend on the polymer 202 used to form polymer barrier 10 and / or the type of polymer 202.

[0054] Exemplary ratios of polymer 202 to diluent 204 in polymer solution 200 may include, but are not limited to, 10:1, 7:1, 5:1, 4:1, 3:1, 2:1, and 1:1, among other possible ratios, each of which is contemplated herein. In a non-limiting example of a polymer solution 200 comprising sodium alginate and GdL, the ratio of sodium alginate to GdL is 1:1 or equal parts of sodium alginate and GdL.

[0055] The amount of polymer solution 200 injected into the vas deferens 30 can be any suitable amount of polymer solution 200 capable of forming a polymer barrier 10 in the vas deferens 30 sufficient to block the outflow of sperm 20. In various embodiments, the amount of polymer solution 200 injected into the vas deferens 30 is particularly in the following ranges, in addition to other possible ranges and / or amounts of polymer solution 200: about one gram (1 g) to about three grams (3 g) by weight and / or about one milliliter (1 mL) or one cubic centimeter (1 cc) to about three milliliters (3 mL) or three cubic centimeters (3 cc) by volume, each of which is contemplated herein. In certain embodiments, the amount of polymer solution 200 injected into the vas deferens 30 is particularly in the following ranges, in addition to other possible ranges and / or amounts of polymer solution 200: about two grams (2 g) by weight and / or about two milliliters (2 mL) or two cubic centimeters (2 cc) by volume, each of which is contemplated herein.

[0056] In practice, a polymer solution 200 comprising a polymer 202 and a diluent 204 is provided to a small gauge needle (eg, a 27 gauge needle or smaller). The diluent 204 acts on the polymer 202 to reduce the viscosity of the polymer 202 and / or the polymer solution 200.

[0057] To insert the polymer solution 200, the male subject is prepared by administering a local anesthetic. A small incision is made in the male subject's scrotum, and the male subject's vas deferens 30 is identified and isolated. A needle is attached to the angiocatheter and inserted at an angle (e.g., an upward angle), wherein a saline flush method may be used to confirm that the needle is inserted at the correct depth in the vas deferens 30. The needle is left in place, the saline syringe is removed and replaced with a contraceptive syringe containing a pre-filled amount of the polymer solution 200, and the polymer solution 200 is dispensed into the vas deferens 30.

[0058] The needle is removed (e.g., pulled out) and the vas deferens 30 is allowed to retreat into the scrotum. The procedure is repeated on the second vas deferens 30 of the male subject. Because the puncture hole is small, no sutures are required and the small incision can heal on its own. Once in the vas deferens 30, the diluent 204 (e.g., GdL, etc.) is metabolized by the male subject, which increases the viscosity of the polymer 202 and / or returns the polymer 202 to its original and / or natural viscosity to form a polymer barrier 10 in the vas deferens 30.

[0059] Over time, the male subject metabolizes the polymer barrier 10, which can enable and / or allow sperm 20 to flow through and / or out of the previously blocked / occluded vas deferens 30. The amount of time to metabolize the polymer barrier 10 can vary depending on the individual. In various embodiments, the polymer barrier 10 can remain effective in blocking sperm 20 for at least one year and up to about two years.

[0060] Figure 3 is a schematic diagram of one embodiment of a calcium chelator 300 (or chelating agent) for degrading the polymer 202 and / or the polymer barrier 10. The calcium chelator 300 may include any one or more suitable solutions and / or substances capable of degrading, dissolving, and / or decomposing the polymer 202 and / or the polymer barrier 10.

[0061] Some non-limiting examples of calcium chelators include, but are not limited to, saline solutions (e.g., phosphate buffered saline (PBS)) and / or water (H2O), among others, in addition to possible chelators and / or substances, each of which is contemplated herein. In some embodiments, the calcium chelator comprises a solution having a pH in the range of about 5 pH to about 10 pH, in addition to possible acidity (pH) levels, in particular, in addition to possible one or more solutions and / or substances, each of which is contemplated herein. In certain embodiments, the calcium chelator 300 comprises, in addition to possible one or more solutions and / or substances, ethylenediaminetetraacetic acid (EDTA), in particular, in addition to possible one or more solutions and / or substances, each of which is contemplated herein.

[0062] At a desired time, calcium chelator 300 may be injected / added to the site of polymer barrier 10 to degrade polymer 202 and / or polymer barrier 10. Calcium chelator 300 acts on polymer 202 and / or polymer barrier 10 to degrade / break down the polymer barrier into particles 302 of polymer 202, which may allow particles 302 to be flushed away from vas deferens 30.

[0063] Any size needle may be used to inject the calcium chelator 300 into the vas deferens 30 and / or polymer barrier 10. In various embodiments, the calcium chelator 300 may be injected using a 27 gauge or smaller needle.

[0064] The amount of calcium chelator 300 injected into the vas deferens 30 and / or polymer barrier 10 can be any suitable amount capable of degrading the polymer 202 and / or polymer barrier 10 in the vas deferens 30 sufficiently to facilitate the outflow of sperm 20. In various embodiments, the amount of calcium chelator 300 injected into the vas deferens 30 and / or polymer barrier 10 is particularly in the following ranges, in addition to possible ranges and / or amounts of calcium chelator 300: about two grams (2g) to about five grams (5g) by weight and / or about 2mL or 2cc to about five milliliters (5mL) or five cubic centimeters (5cc) by volume, each of which is contemplated herein. In certain embodiments, the amount of calcium chelator 300 injected into the vas deferens 30 and / or polymer barrier 10 is particularly in the following ranges, in addition to possible ranges and / or amounts of calcium chelator 300: about 2g by weight and / or 2mL / 2cc by volume, each of which is contemplated herein.

[0065] To insert the calcium chelator 300, the male subject is prepared by administering a local anesthetic. A small incision is made in the male subject's scrotum, and the male subject's vas deferens 30 is identified and isolated. The location and / or site of the polymer barrier 10 is identified and isolated.

[0066] The needle is attached to the angiocatheter and inserted at an angle (e.g., an upward angle), wherein a saline flush method may be used to confirm that the needle is inserted at the correct depth into the vas deferens 30. The needle is left in place, the saline syringe is removed and replaced with a syringe containing a pre-filled amount of the calcium chelator 300, and the calcium chelator 300 is dispensed into the vas deferens 30 and / or polymer barrier 10, and the vas deferens 30 is flushed with saline solution (e.g., 2 mL / cc of saline solution).

[0067] The needle is removed (e.g., pulled out) and the vas deferens 30 is allowed to retreat into the scrotum. The process is repeated on another polymer barrier 10 in the male subject's second vas deferens 30. Because the puncture hole is small, no sutures are required and the small incision can heal on its own.

[0068] After the polymer 202 and / or polymer barrier 10 is sufficiently degraded and / or caused to degrade, the sperm 20 is no longer blocked and is able to flow through the vas deferens 30. Here, because the polymer barrier 10 is freely degradable, this form of male birth control is considered temporary and / or reversible.

[0069] Figure 4 Contains spermicide (see Figure 5 Schematic diagram of one embodiment of a polymer barrier 400 having a spermicide 504 in a vas deferens 30 that can be injected or otherwise placed in the vas deferens 30 of a male subject. The polymer barrier 400 can physically block or at least partially block the outflow of sperm 20 in the vas deferens 30, and the spermicide can chemically incapacitate the sperm 20. In this way, the polymer barrier 400 can create a double barrier defense against sperm 20 in the vas deferens 30.

[0070] Figure 5 is a polymer barrier 400 (see Figure 4 ) that includes a spermicide to physically block or at least partially block and / or incapacitate sperm 20 in the vas deferens 30 of a male subject. In various embodiments, a first portion of the polymer solution 500 includes a polymer 502, and a second portion of the polymer solution 500 includes a spermicide 504.

[0071] The polymer 502 may include any one or more suitable polymers known or developed in the future that can be inserted into the vas deferens 30 of a male subject and form a polymer barrier 400 to physically block the outflow of sperm 20. The polymer 502 may include liquid and / or solid chemical states; in some embodiments, the polymer 502 includes, among other possible suitable polymers and / or substances, a hydrogel, each of which is contemplated herein.

[0072] In various embodiments, the polymer 502 is biocompatible. In some embodiments, the biocompatible polymer 502 comprises a polysaccharide, which may comprise any suitable polysaccharide.

[0073] In certain embodiments, the polysaccharide comprises alginate, which may comprise any suitable alginate. In one embodiment, the alginate comprises, among other possible and contemplated suitable alginates, sodium alginate.

[0074] The polymer solution 500 can include any suitable amount of polymer 502 that can form a polymer barrier 400 in the vas deferens 30 sufficient to physically block or at least partially block the outflow of sperm 20. In various embodiments, the amount of polymer 502 in the polymer solution 500 is particularly in the following ranges, in addition to possible ranges and / or amounts of polymer 502: about 1 g to about 3 g by weight and / or about 1 mL / cc to about 3 mL / cc by volume, each of which is contemplated herein. In certain embodiments, the amount of polymer 502 in the polymer solution 500 is particularly in the following ranges, in addition to possible ranges and / or amounts of polymer 502: about 2 g by weight and / or about 2 mL / cc by volume, each of which is contemplated herein.

[0075] Spermicide 504 may include any one or more suitable substances capable of incapacitating (eg, killing) sperm 20. In some embodiments, spermicide 504 may include sperm inhibitors or other mechanisms capable of incapacitating sperm 20.

[0076] In various embodiments, spermicide 504 can include any suitable chemical, drug, hormone, element and / or other composition capable of incapacitating sperm 30. In various embodiments, spermicide 504 includes, in addition to possible one or more substances, calcium channel blockers, essential oils (e.g., neem oil, etc.), and / or citric acid, each of which is contemplated herein. In one embodiment, calcium channel blockers include, in addition to possible channel blockers, nifedipine, each of which is contemplated herein. In additional or alternative embodiments, spermicide 504 includes an acid (e.g., pH less than 7 pH).

[0077] In various embodiments, the concentration of spermicide 504 can be maintained within polymer barrier 400 for about one year (see Fig. 10A and 10B ). That is, Fig. 10A and 10B The concentration of one embodiment of spermicide 504 in polymer barrier 400 is shown over a period of about one year.

[0078] The polymer solution 500 may include any suitable amount of spermicide 504 that can incapacitate sperm 20. In certain embodiments, the amount of spermicide 504 in the polymer solution 500 may include about 4.676 le, in addition to possible greater or lesser concentrations of spermicide 504. -7 mol / m 3 concentrations, each of which is contemplated herein (see Fig. 10A and 10B ).

[0079] In some embodiments, the spermicide 504 is contained and / or stored in a plurality of particles 600, which may be contained / dispersed in a polymer solution 500, such as Figure 6 The particles 600 are configured to encapsulate the spermicide 504 so that the spermicide can interact with any sperm 20 that comes into contact with the polymer barrier 400 to render the sperm 20 incapacitated.

[0080] Figure 6 One embodiment of a particle 600 comprising a spermicide 504 is shown. The particle 600 can be made of any suitable material capable of accommodating the spermicide 504. In various embodiments, the particle 600 includes a polymer and / or a biocompatible polymer. In certain embodiments, the particle 600 includes, among other possible polymers, poly-L-lactic acid (PLLA) and / or poly (lactic-co-glycolic acid) (PLGA), each of which is contemplated herein.

[0081] Particles 600 may include any suitable size and / or shape capable of containing spermicide 504. In some embodiments, particles 600 may include microns (10 -6 meters) and / or nanometers (10 -9 ) scale, each of which is contemplated herein.

[0082] like Figure 7 As shown, microparticles 600 include a plurality of pores 702 configured to encapsulate spermicide 504. Pores 702 may include any suitable size and / or shape that enables / permits spermicide to reside therein.

[0083] In some embodiments, the pores 702 include dimensions and / or gaps of approximately five nanometers (5 nm). The pores 702 may be filled with spermicide 504 by physical bonding and / or chemical bonding to encapsulate the spermicide 504 for up to one year (see Fig. 10A and 10B ).

[0084] Reference again Figure 5, a polymer solution 500 comprising a polymer 502 and a spermicide 504 is provided to a hypodermic needle for injection into the vas deferens 30 of a male subject. The needle may comprise any size needle capable of delivering the polymer solution 500 to the vas deferens 30.

[0085] To create the polymer barrier 400 in the vas deferens 30 using the polymer solution 500, the male subject is prepared by administering a local anesthetic. An incision is made in the male subject's scrotum, and the male subject's vas deferens 30 is identified and isolated. A needle is attached to an angiocatheter and inserted at an angle (e.g., an upward angle), wherein a saline flush method may be used to confirm that the needle is inserted at the correct depth in the vas deferens 30. The needle is left in place, the saline syringe is removed and replaced with a contraceptive syringe containing a pre-filled amount of the polymer solution 500, and the polymer solution 500 is dispensed into the vas deferens 30.

[0086] The needle is removed (e.g., pulled out) and the vas deferens 30 is allowed to retreat into the scrotum. The procedure is repeated on the male subject's second vas deferens 30. In this manner, a polymer barrier 400 containing spermicide 504 is created in each vas deferens 30 of the male subject.

[0087] Over time, the male subject metabolizes the polymer barrier 400, polymer 502, and / or spermicide 504, which can enable and / or allow sperm 20 to flow through and / or out of the vas deferens 30. The amount of time to metabolize the polymer barrier 400, polymer 502, and / or spermicide 504 can vary from individual to individual. In various embodiments, the polymer barrier 400, polymer 502, and / or spermicide 504 can remain effective in blocking and / or incapacitating sperm 20 for at least one year and up to about two years.

[0088] Figure 8 is a polymer barrier 400 (see Figure 4 ) that includes a spermicide to physically block or at least partially block and / or incapacitate sperm 20 in the vas deferens 30 of a male subject. In various embodiments, a first portion of polymer solution 800 includes polymer 202, a second portion of polymer solution 800 includes diluent 204, and a third portion of polymer solution 800 includes spermicide 504.

[0089] Polymer 202 may include reference Figure 2 Any embodiment of the polymer 202 included in the polymer solution 200 discussed above. The diluent 204 may include reference Figure 2Any embodiment of the diluent 204 included in the polymer solution 200 discussed above. The spermicide 504 may include reference Figure 5 Any embodiment of the spermicide 504 included in the polymer solution 500 discussed.

[0090] To create polymer barrier 400 in vas deferens 30 using polymer solution 800, polymer solution 800 is provided to a small gauge needle (eg, 27 gauge needle or smaller). Diluent 204 acts on polymer 202 containing spermicide 504 to reduce the viscosity of polymer 202 and / or polymer solution 800.

[0091] To insert the polymer solution 800, the male subject is prepared by administering a local anesthetic. A small incision is made in the male subject's scrotum, and the male subject's vas deferens 30 is identified and isolated. A needle is attached to the angiocatheter and inserted at an angle (e.g., an upward angle), wherein a saline flush method may be used to confirm that the needle is inserted at the correct depth in the vas deferens 30. The needle is left in place, the saline syringe is removed and replaced with a contraceptive syringe containing a pre-filled amount of polymer solution 800, and the polymer solution 800 is dispensed into the vas deferens 30.

[0092] The needle is removed (e.g., pulled out) and the vas deferens 30 is allowed to retreat into the scrotum. The procedure is repeated on the second vas deferens 30 of the male subject. Because the puncture hole is small, no sutures are required and the small incision can heal on its own. Once in the vas deferens 30, the diluent 204 (e.g., GdL, etc.) is metabolized by the male subject, which increases the viscosity of the polymer 202 and / or returns the polymer 202 to its original and / or natural viscosity to form a polymer barrier 400 in the vas deferens 30.

[0093] Over time, the male subject metabolizes the polymer barrier 400, polymer 202, and / or spermicide 504, which can enable and / or allow sperm 20 to flow through and / or out of the previously blocked / occluded vas deferens 30. The amount of time to metabolize the polymer barrier 400, polymer 202, and / or spermicide 504 can vary depending on the individual. In various embodiments, the polymer barrier 400 and / or spermicide 504 can remain effective for at least one year and up to two years.

[0094] Fig. 9is a schematic diagram of one embodiment of a calcium chelator 900 for degrading polymer barrier 400 and / or spermicide 504. Calcium chelator 900 may include any one or more suitable solutions and / or substances capable of degrading, dissolving, and / or decomposing polymer barrier 400 and / or spermicide 504. In certain embodiments, calcium chelator 900 includes ethylenediaminetetraacetic acid (EDTA), among other possible one or more solutions and / or substances, each of which is contemplated herein.

[0095] At a desired time, a calcium chelator 900 may be injected / added to the site of the polymer barrier 400 to degrade the polymer 202 and / or spermicide 504. The calcium chelator 900 acts on the polymer 202 and / or spermicide 504 to degrade / break down the polymer barrier 400 into particles 902 of the polymer 202 and / or spermicide 504, which may allow the particles 902 to be flushed away from the vas deferens 30.

[0096] Any size needle may be used to inject the calcium chelator 900 into the vas deferens 30 and / or polymer barrier 400. In various embodiments, the calcium chelator 900 may be injected using a 27 gauge or smaller needle.

[0097] The amount of calcium chelator 900 injected into the vas deferens 30 and / or polymer barrier 400 can be any suitable amount capable of degrading the polymer 202 and / or spermicide 504 in the vas deferens 30 sufficiently to facilitate the outflow of sperm 20. In various embodiments, the amount of calcium chelator 900 injected into the vas deferens 30 and / or polymer barrier 900 is particularly in the following ranges, in addition to possible ranges and / or amounts of calcium chelator 300: about 2 g to about 5 g by weight and / or 2 ml / cc to about 5 mL / cc by volume, each of which is contemplated herein. In certain embodiments, the amount of calcium chelator 900 injected into the vas deferens 30 and / or polymer barrier 400 is particularly in the following ranges, in addition to possible ranges and / or amounts of calcium chelator 300: about 2 g by weight and / or 2 mL / cc by volume, each of which is contemplated herein.

[0098] To insert the calcium chelator 900, the male subject is prepared by administering a local anesthetic. A small incision is made in the male subject's scrotum, and the male subject's vas deferens 30 is identified and isolated. The location and / or position of the polymer barrier 400 is identified and isolated.

[0099] The needle is attached to the angiocatheter and inserted at an angle (e.g., an upward angle), wherein a saline flush method may be used to confirm that the needle is inserted at the correct depth into the vas deferens 30. The needle is left in place, the saline syringe is removed and replaced with a syringe containing a pre-filled amount of calcium chelator 900, and the calcium chelator 900 is dispensed into the vas deferens 30 and / or polymer barrier 400, and then flushed with saline solution, similar to other embodiments discussed elsewhere herein.

[0100] The needle is removed (e.g., pulled out) and the vas deferens 30 is allowed to retreat into the scrotum. The process is repeated on another polymer barrier 400 in the second vas deferens 30 of the male subject. Because the puncture hole is small, no sutures are required and the small incision can heal on its own.

[0101] After the polymer barrier 400 and / or spermicide 504 are sufficiently degraded, the sperm 20 is no longer blocked and is able to flow through the vas deferens 30. Here, because the polymer barrier 400 and spermicide 504 are freely degradable, this form of male birth control is considered temporary and / or reversible.

[0102] Fig.11 is a block diagram of one embodiment of a method 1100 for male birth control. At least in the illustrated embodiment, the method 1100 may begin by providing a polymer 202 including a viscosity (block 1102); in various embodiments, providing the polymer 202 includes providing a biocompatible polymer, providing a polysaccharide, providing an alginate, and / or providing sodium alginate.

[0103] Method 1100 further includes reducing the viscosity of polymer 202 to produce polymer solution 200 (block 1104); in various embodiments, reducing the viscosity of polymer 202 and / or producing polymer solution 200 is accomplished by mixing diluent 204 (eg, GdL) with polymer 202 and / or adding the diluent to the polymer.

[0104] While reducing the viscosity of the polymer 202, the polymer solution 200 is injected into the vas deferens 30 of the male subject (block 1106). In various embodiments, the polymer barrier 10 to sperm is formed after the polymer solution 200 is injected into the vas deferens 30. The method 1100 can provide temporary and / or reversible male birth control.

[0105] Fig.12 1 is a block diagram of another embodiment of a method 1200 for male birth control, at least in the illustrated embodiment, the method 1200 can begin by providing a polymer 202 including a viscosity (block 1202). In various embodiments, providing the polymer 202 includes providing a biocompatible polymer, providing a polysaccharide, providing an alginate, and / or providing sodium alginate.

[0106] Method 1200 further includes reducing the viscosity of polymer 202 to produce polymer solution 200 (block 1204). In various embodiments, reducing the viscosity of polymer 202 and / or producing polymer solution 200 is accomplished by mixing diluent 204 (eg, GdL) with polymer 202 and / or adding the diluent to the polymer.

[0107] While reducing the viscosity of the polymer 202, the polymer solution 200, 800 is injected into the vas deferens 30 of the male subject (block 1206). In various embodiments, the polymer barrier 10 to sperm is formed after the polymer solution 200 is injected into the vas deferens 30.

[0108] A calcium chelator 300 (e.g., EDTA) is injected into the vas deferens 30 to degrade the polymer barrier 10 (block 1208). Any size needle may be used and in some embodiments, a 27 gauge or smaller needle is used to inject the calcium chelator 300. In various embodiments, the method 1200 may provide temporary and / or reversible male birth control.

[0109] Fig.13 is a block diagram of another embodiment of a method 1300 for male birth control. In at least the illustrated embodiment, the method 1300 may begin by providing a polymer 502 and a spermicide 504 to form a polymer solution 500 (block 1302).

[0110] In various embodiments, providing polymer 502 includes providing a biocompatible polymer, providing a polysaccharide, providing an alginate, and / or providing sodium alginate. Additionally, spermicide 504 may include a calcium channel blocker and / or nifedipine, as discussed elsewhere herein.

[0111] A polymer solution 500 comprising a polymer 502 and a spermicide 504 is injected into the vas deferens 30 of a male subject (block 1304). In various embodiments, the polymer barrier 400 may be formed after the polymer solution 500 is injected into the vas deferens 30. The method 1300 may provide temporary and / or reversible male birth control.

[0112] Fig.14 is a block diagram of another embodiment of a method 1400 for male birth control. In at least the illustrated embodiment, the method 1400 may begin by providing a polymer 502 and a spermicide 504 to form a polymer solution 500 (block 1402).

[0113] In various embodiments, providing polymer 502 includes providing a biocompatible polymer, providing a polysaccharide, providing an alginate, and / or providing sodium alginate. Additionally, spermicide 504 may include a calcium channel blocker and / or nifedipine, as discussed elsewhere herein.

[0114] A polymer solution 500 comprising a polymer 502 and a spermicide 504 is injected into the vas deferens 30 of a male subject (block 1404 ). In various embodiments, the polymer barrier 400 may be formed after the polymer solution 500 is injected into the vas deferens 30 .

[0115] A calcium chelator 900 (eg, EDTA) may be injected into the vas deferens 30 to degrade the polymer 502 and / or spermicide 504 (block 1406). The method 1400 may provide temporary and / or reversible male birth control.

[0116] Fig.15 is a block diagram of another embodiment of a method 1500 for male birth control. In at least the illustrated embodiment, the method 1500 may begin by providing a polymer 202 and a spermicide 504 (block 1502).

[0117] In various embodiments, providing the polymer 202 includes providing a biocompatible polymer, providing a polysaccharide, providing an alginate, and / or providing sodium alginate. Additionally, the spermicide 504 may include a calcium channel blocker and / or nifedipine, as discussed elsewhere herein.

[0118] Method 1500 further includes reducing the viscosity of polymer 202 to produce polymer solution 800 (block 1504). In various embodiments, reducing the viscosity of polymer 202 and / or producing polymer solution 800 is accomplished by mixing diluent 204 (eg, GdL) with polymer 202 and / or adding the diluent to the polymer.

[0119] While reducing the viscosity of the polymer 202, the polymer solution 800 is injected into the vas deferens 30 of the male subject (block 1506). In various embodiments, the polymer barrier 400 to sperm is formed after the polymer solution 800 is injected into the vas deferens 30. The method 1500 can provide temporary and / or reversible male birth control.

[0120] Fig.16 is a block diagram of another embodiment of a method 1600 for male birth control. In at least the illustrated embodiment, the method 1600 may begin by providing a polymer 202 and a spermicide 504 (block 1602).

[0121] In various embodiments, providing the polymer 202 includes providing a biocompatible polymer, providing a polysaccharide, providing an alginate, and / or providing sodium alginate. Additionally, the spermicide 504 may include a calcium channel blocker and / or nifedipine, as discussed elsewhere herein.

[0122] Method 1600 further includes reducing the viscosity of polymer 202 to produce polymer solution 800 (block 1604). In various embodiments, reducing the viscosity of polymer 202 and / or producing polymer solution 800 is accomplished by mixing diluent 204 (eg, GdL) with polymer 202 and / or adding the diluent to the polymer.

[0123] While reducing the viscosity of the polymer 202, the polymer solution 800 is injected into the vas deferens 30 of the male subject (block 1606). In various embodiments, the polymer barrier 400 against sperm is formed after the polymer solution 800 is injected into the vas deferens 30.

[0124] A calcium chelator 900 (eg, EDTA) may be injected into the vas deferens 30 to degrade the polymer 502 and / or spermicide 504 (block 1606). The method 1600 may provide temporary and / or reversible male birth control.

[0125] Fig.17 is a block diagram of another embodiment of a method 1700 for male birth control. In at least the illustrated embodiment, the method 1700 may begin by positioning the polymeric barrier 10 into the vas deferens 30 of a male subject (block 1702).

[0126] The polymer barrier 400 may be located using any suitable method and / or technique known or developed in the future that is capable of locating a substance in the vas deferens 30. In some embodiments, the polymer barrier 400 includes a dye (e.g., a fluorescent dye (e.g., indocyanine green (ICG), etc.), etc.), and visual imaging may be used to locate the polymer barrier 400 via the dye in the polymer barrier 400. In additional or alternative embodiments, ultrasound is used to locate the polymer barrier 400.

[0127] The calcium chelator 300 may be injected into the vas deferens 30 to degrade the polymer barrier 10 (block 1704). In various embodiments, the calcium chelator 300 may include EDTA, among other possible calcium chelators, each of which is contemplated herein.

[0128] Fig.18 is a block diagram of yet another embodiment of a method 1800 for male birth control. In at least the illustrated embodiment, the method 1800 may begin by positioning a polymeric barrier 400 into the vas deferens 30 of a male subject (block 1802).

[0129] The polymer barrier 400 may be located using any suitable method and / or technique known or developed in the future that is capable of locating a substance in the vas deferens 30. In some embodiments, the polymer barrier 400 includes a dye (e.g., a fluorescent dye (e.g., indocyanine green (ICG), etc.), etc.), and visual imaging may be used to locate the polymer barrier 400 via the dye in the polymer barrier 400. In additional or alternative embodiments, ultrasound is used to locate the polymer barrier 400.

[0130] Calcium chelator 900 may be injected into vas deferens 30 to degrade polymer barrier 400 and / or spermicide 504 (block 1804). In various embodiments, calcium chelator 900 may include EDTA, among other possible calcium chelators, each of which is contemplated herein.

[0131] Fig.19 is a block diagram of another embodiment of a method 1900 for male birth control. In at least the illustrated embodiment, the method 1900 may begin by reducing the viscosity of a polymer 202 to produce a polymer solution 200 (block 1902).

[0132] The polymer 202 may include a biocompatible polymer, a polysaccharide, an alginate, and / or sodium alginate, as discussed elsewhere herein. In various embodiments, the viscosity of the polymer 202 is reduced and / or the polymer solution 200 is produced by mixing a diluent 204 (e.g., GdL) with the polymer 202 and / or adding a diluent to the polymer.

[0133] While reducing the viscosity of the polymer 202, the polymer solution 200 is injected into the vas deferens 30 of the male subject (block 1904). In various embodiments, the polymer barrier 10 against sperm is formed after the polymer solution 200 is injected into the vas deferens 30.

[0134] The polymer barrier 10 is positioned into the vas deferens 30 (block 1906), and a calcium chelator 300 (eg, EDTA) may be injected into the vas deferens 30 to degrade the polymer barrier 10 (block 1908). The method 1900 may provide temporary and / or reversible male birth control.

[0135] Fig. 20 is a block diagram of an embodiment of a method 2000 for male birth control. In at least the illustrated embodiment, the method 2000 may begin by reducing the viscosity of a polymer 202 containing a spermicide 504 to produce a polymer solution 800 (block 2002).

[0136] The polymer 202 may include a biocompatible polymer, a polysaccharide, an alginate, and / or sodium alginate, as discussed elsewhere herein. In addition, the spermicide 504 may include a calcium channel blocker and / or nifedipine, as discussed elsewhere herein. In various embodiments, the viscosity of the polymer 202 is reduced and / or a polymer solution 800 is produced by mixing a diluent 204 (e.g., GdL) with the polymer 202 and / or adding a diluent to the polymer.

[0137] While reducing the viscosity of the polymer 202, the polymer solution 800 is injected into the vas deferens 30 of the male subject (block 1904). In various embodiments, the polymer barrier 400 against sperm is formed after the polymer solution 800 is injected into the vas deferens 30.

[0138] The polymer barrier 400 is positioned into the vas deferens 30 (block 2006), and a calcium chelator 900 (eg, EDTA) may be injected into the vas deferens 30 to degrade the polymer barrier 400 and / or spermicide 504 (block 2008). The method 2000 may provide temporary and / or reversible male birth control.

[0139] References to an embodiment, an embodiment, or similar language throughout the specification are intended to refer to specific features, structures, or characteristics described in conjunction with the embodiment, which are included in at least one embodiment. Therefore, unless otherwise expressly specified, throughout the specification, phrases in one embodiment, in an embodiment, and the appearance of similar language may but not necessarily all refer to the same embodiment, but to one or more but not all embodiments; unless otherwise expressly specified, the terms include / contain, have, and their variants are intended to include but are not limited to. Unless otherwise expressly specified, the enumerated list of items does not mean that any or all items are mutually exclusive. Unless otherwise expressly specified, the terms "one / a kind (a)", "one / a kind (an)" and "the / said (the)" also refer to one or more / one or more.

[0140] In addition, the features, structures, or characteristics of the described embodiments may be combined in any suitable manner. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific details or with other methods, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments.

[0141] Various aspects of the embodiments are described above with reference to schematic flow charts and / or schematic block diagrams of particles (e.g., silver particles 100) and methods according to various embodiments. It should also be noted that in some alternative implementations, the functions marked in the boxes may not occur in the order marked in the figure. For example, two boxes shown in succession may actually be executed substantially simultaneously, or the boxes may sometimes be executed in the opposite order, depending on the functions involved. Other steps and methods that are equivalent in function, logic, or effect to one or more boxes or portions thereof of the illustrated figures can be envisioned.

[0142] Although various arrow types and line types may be employed in the flowcharts and / or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiments. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiments.

[0143] The description of elements in each figure may refer to elements of the previous figure. Like numbers refer to like elements in all figures (including alternative embodiments of like elements).

[0144] The various disclosed embodiments may be practiced in other specific forms. The described embodiments should be considered in all respects to be illustrative only and not restrictive. Therefore, the scope of the present invention is indicated by the appended claims rather than the foregoing description. All changes within the meaning and scope of the equivalents of the claims should be included within their scope.

Claims

1. A method comprising: providing a polymer including a viscosity; reducing the viscosity of the polymer to produce a polymer solution; as well as injecting the polymer solution into the vas deferens of a subject while reducing the viscosity of the polymer, The polymer solution forms a polymer barrier against sperm after injection. 2 . The method of claim 1 , wherein providing the polymer comprises providing a biocompatible polymer.

3. The method of claim 2, wherein providing the biocompatible polymer comprises providing a polysaccharide. The method of claim 3 , wherein providing the polysaccharide comprises providing alginate.

5. The method of claim 4, wherein providing the alginate comprises providing sodium alginate.

6. The method of claim 1, wherein reducing the viscosity of the polymer comprises reducing the viscosity of the polymer to allow dispensing of the polymer solution via a small gauge hypodermic needle.

7. The method of claim 6, wherein the small gauge hypodermic needle comprises a hypodermic needle comprising a gauge less than or equal to 27 gauge.

8. The method of claim 7, wherein injecting the polymer solution comprises injecting the polymer solution into the vas deferens of the subject using the small gauge hypodermic needle while reducing the viscosity of the polymer.

9. The method of claim 1, wherein reducing the viscosity of the polymer comprises temporarily reducing the viscosity of the polymer.

10. The method of claim 9, wherein temporarily reducing the viscosity of the polymer comprises mixing the polymer with glucono-delta-lactone (GdL) to produce the polymer solution.

11. The method according to claim 10, wherein: The polymer solution forms the polymer barrier to sperm in response to being present in the vas deferens for a predetermined amount of time; and The predetermined amount of time is the amount of time for the subject to metabolize the GdL.

12. The method of claim 1, wherein the polymer solution forms the polymer barrier to sperm for an amount of time that the subject metabolizes the polymer.

13. The method of claim 12, wherein the amount of time is at least one year.

14. The method of claim 1, further comprising injecting a calcium chelator into the vas deferens to degrade the polymer barrier.

15. The method of claim 14, wherein injecting the calcium chelator into the vas deferens comprises injecting ethylenediaminetetraacetic acid (EDTA) into the vas deferens.

16. The method of claim 15, wherein injecting the EDTA into the vas deferens comprises injecting the EDTA into the vas deferens via a hypodermic needle comprising a gauge less than or equal to 27 gauge.

17. A method comprising: positioning a polymer barrier against sperm into the vas deferens of a subject; and A calcium chelator is injected into the vas deferens to degrade the polymer barrier.

18. The method of claim 17, wherein the calcium chelator comprises ethylenediaminetetraacetic acid (EDTA).

19. A method comprising: reducing the viscosity of the polymer to produce a polymer solution; injecting the polymer solution into the vas deferens of a subject while reducing the viscosity of the polymer to create a polymer barrier to sperm in the vas deferens after the viscosity of the polymer increases while present in the vas deferens; positioning the polymer barrier into the vas deferens; as well as A calcium chelator is injected into the vas deferens to degrade the polymer barrier.

20. The method of claim 19, wherein: The polymer comprises sodium alginate; and The calcium chelating agent includes ethylenediaminetetraacetic acid (EDTA).

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