Disclosed herein include embodiments related to compositions, devices, computer systems, computer-implemented methods, and computer program products associated with an ingestible salt grabber.

SUMMARY

The present disclosure relates to compositions comprising, for example, a housing including at least one ingestible resin and one or more controllable ports. The present disclosure relates to compositions, among other things, including at least one ingestible resin and one or more cell surface molecules. The present disclosure relates to articles of manufacture including, among other things, an article including a composition having a housing with one or more controllable ports, and at least one ingestible resin. Also included herein are foodstuffs including an ion exchange resin and an ingestible food product. Also disclosed herein are articles of manufacture including an article including a composition having an ingestible resin and one or more cell surface molecules. In an embodiment, a method of modulating at least one ion in a biological tissue includes providing a composition to a biological tissue, the composition including a housing and at least one ingestible resin, and one or more controllable ports.

DETAILED DESCRIPTION

Living subjects require ions for survival. However, in certain instances a subject may consume or otherwise ingest too much of one or more ions, which can cause detrimental biological consequences. For example, too much sodium has been linked to high blood pressure, obesity, heart attack, stroke, and other health problems in humans. See, for example, Strauss, Nat. Med. Vol. 16, no. 8, pp. 841-843 (2010), which is incorporated herein by reference. In an embodiment disclosed herein, compositions and methods relate to capturing one or more types of ions ingested by a subject. In an embodiment, the compositions and methods relate to retaining the ions for excretion, rather than absorption, by the subject.

In an embodiment, the composition includes a housing including at least one ingestible resin and one or more controllable ports. In an embodiment, the housing includes at least one of a coating, or other enclosure (e.g., capsule, frame, container, device, microchip, silicon wafer, etc.). In an embodiment, the composition includes at least two resins. In an embodiment, the composition includes at least two different resins. In an embodiment, the housing is heterogeneous (e.g., coating on a portion of the composition, and device on a portion of the composition, etc.) In an embodiment, the composition further includes one or more resins located externally to the housing. In an embodiment, the one or more resins located externally to the housing provide an additional binding capacity for the same target ion or a different target ion, of the resin located internal to the housing.

In an embodiment, the composition includes an ion exchange resin including one or more controllable ports. In an embodiment, the resin includes at least one polymer. In an embodiment, the at least one polymer includes at least one of polyester, polylactic acid, polylactic-co-glycolic acid, cellulose, nitrocellulose, urea, urethane, phosphatidylcholine, cholesterol, phosphatidylethanolamine, phospholipid, ganglioside, dioleoylphosphatidylethanolamine, surfactant, polyacid, phthalate, chitin, chitosan, collagen, polyethylene oxide, poly ((β-benzyl-L-aspartate), poly (ε-caprolactone), poly(DL-lactide-co-glycolide), polybutylcyanoacrylate, alginate, poly(adipic anhydride), gelatin, 1,5-dioxepan-2-one, D,L-dilactide, or other polymer. In an embodiment, the at least one polymer includes at least one of polyvinyl acetate phthalate, hydroxypropyl methyl cellulose phthalate, methacrylic acid-methacrylic acid ester copolymers, cellulose acetate trimellitate, carboxymethyl ethylcellulose, hydroxypropyl methylcellulose acetate succinate, cellulose acetate phthalate, poly(methacrylic acid), or other polymer. In an embodiment, the polymer includes polyfluoroacrylic acid (polyFAA). In an embodiment, the polymer includes a crosslinked cation exchange polymer salt and an effective amount of a linear polyol sufficient to stabilize the polymer salt. See, for example U.S. Patent App. Pub. No. 2010/0111891, which is incorporated herein by reference. In an embodiment, the composition further comprises water, for example, in an amount sufficient to reduce or assist in the release of the ion from an ion-loaded exchange resin during storage.

In an embodiment, a linear polyol is added to the composition as a stabilizer for the polymer salt. For example, in an embodiment the linear polyol includes at least one of a linear sugar (i.e., a linear sugar alcohol). In an embodiment, the linear sugar alcohol includes at least one of D-(+) arabitol, erythritol, glycerol, maltitol, D-mannitol, ribitol, D-sorbitol, xylitol, threitol, galactitol, isomalt, iditol, lactitol, and the like, or any combinations thereof. In an embodiment, the linear polyol is present from at least about 1 wt. %, at least about 2 wt. %, at least about 3 wt. %, at least about 4 wt. %, at least about 5 wt. %, at least about 6 wt. %, at least about 7 wt. %, at least about 8 wt. %, at least about 9 wt. %, at least about 10 wt %, at least about 15 wt. %, at least about 20 wt. %, at least about 25 wt. %, at least about 30 wt. %, at least about 35 wt. %, at least about 40 wt. %, at least about 45 wt. %, at least about 50 wt. %, at least about 55 wt. %, at least about 60 wt. %, or any amount therebetween or greater.

In an embodiment, the ion exchange resin is loaded with an ion (e.g., hydrogen, ammonium, lithium, etc.) that is displaced (often referred to as “exchanged”) upon binding of another ion (e.g., the target ion) from the biological tissue. See, e.g., Friedman, “Problems of Cation-Exchange-Resin Therapy,” available online. See for example, the worldwide web at archinternmed.com, last visited on Apr. 13, 2010, the contents of which are incorporated herein by reference.

For example, certain polymers include particular desirable characteristics for use with the resin or housing, including: poly(urethanes) for elasticity; poly(siloxanes) or silicones for insulating ability; poly(methyl methacrylate) for physical strength and transparency; poly(vinyl alcohol) for hydrophilicity and strength; poly(ethylene) for toughness and lack of swelling; poly(vinyl pyrrolidone) for suspension capabilities, etc. Several polymers (such as poly(2-hydroxyethylmethacrylate); poly(N-vinyl pyrrolidone); poly(vinyl alcohol); poly(acrylic acid); polyacrylamide; poly(ethylene-co-vinyl acetate); poly(ethylene glycol); poly(methacrylic acid), etc.) are utilized for controlled drug delivery. Certain polymers (such as polylactides, polyglycolides, poly(lactide-co-glycolides), polyanhydrides, and polyorthoesters) degrade within a biological tissue, or in a biological subject's body. For example, in an embodiment, one or more polymers are inter-mixed with the resin, or is included as a part or all of the housing for the resin.

In an embodiment, the biological subject includes at least one vertebrate or invertebrate animal. In an embodiment, the biological subject includes a plant (e.g., the ingestible salt grabber is ingested by the plant via uptake from the roots, or transfer to xylum or phloem). For example, in soil that contains a particular high level of an ion (e.g., contaminated soil) such compositions assist in removing toxicity from soil and speed clean up of the site.

In an embodiment, acidic or basic hydrogels respond to particular changes in pH (for example, by swelling). In an embodiment, ionic hydrogels respond to a change in ionic strength (for example by swelling).

In at least one embodiment, the at least one biological tissue is at least partially located in a biological subject. In an embodiment, as discussed herein, a biological subject includes, but is not limited to, a vertebrate or invertebrate, including a fish, reptile, mammal, amphibian, or bird. In at least one embodiment, the biological subject includes at least one human. In an embodiment, the at least one biological subject includes at least one of livestock, pet, zoo animal, undomesticated herd animal, wild animal, aquatic plant or animal, or product animal.

In an embodiment, the at least one biological subject includes at least one of a sheep, goat, frog, dog, cat, rat, mouse, vermin, monkey, horse, cow, pig, chicken, shellfish, fish, turkey, llama, alpaca, bison, buffalo, ape, primate, ferret, wolf, fox, coyote, deer, rabbit, guinea pig, yak, chinchilla, mink, reindeer, elk, camel, fox, elk, deer, raccoon, donkey, or mule. In an embodiment, the at least one biological subject includes at least one anthozoan species. In an embodiment, the at least one biological subject includes at least one of a sea anemone, coral, mollusk, fish, whale, dolphin, porpoise, seal, otter, beaver, seabird, gull, pelican, albatross, duck, swan; or goose. In an embodiment, the at least one subject includes at least one insect (e.g., fly, mosquito, beetle, moth, butterfly, etc.). In an embodiment, the at least one biological subject includes at least one arachnid. In an embodiment, the at least one biological subject includes at least one crustacean.

In an embodiment, the biological subject includes a plant. In an embodiment, the at least one biological tissue includes one or more of a stalk, stem, leaf, root, plant, or tendril. In an embodiment, the at least one biological tissue includes at least one food product. In an embodiment, the at least one food product includes one or more animal, plant, fungal or other biological food product. In an embodiment, the food product includes meat. In an embodiment, the at least one biological tissue includes at least one cell mass or wound.

In an embodiment, the at least one composition is self-administered by the at least one subject. In an embodiment, the at least one composition is ingested by the at least one subject. In an embodiment, the at least one biological tissue includes at least one implantable or transplantable biological tissue. In an embodiment, the at least one biological tissue is transplanted or implanted into at least one subject. In an embodiment, the at least one biological tissue is from at least one donor or recipient. In an embodiment, the at least one biological tissue includes at least one bodily orifice of a subject.

In an embodiment, at least one component of the composition is biodegradable. In an embodiment, hydrogels containing electron-accepting groups respond to electron-donating compounds by forming charge/transfer complexes (for example, by swelling). In an embodiment, hydrogels containing immobilized enzymes respond to particular substrates, such as enzyme conversion (for example, by swelling). In an embodiment, ferrogels respond to magnetic fields by swelling (as a result of changes in pore size of the gel). In an embodiment, thermoresponsive hydrogels (e.g., poly (N-isopropylacrylamide) respond to changes in temperature by changes in polymer-polymer and water-polymer interactions (for example, by swelling). In an embodiment, a polyelectrolyte hydrogel responds to an applied electric field, such as with membrane charging or electrophoresis of charged therapeutics contained therein, by releasing the therapeutic. In an embodiment, ethylene-vinyl alcohol hydrogels respond to ultrasound irradiation and temperature increase by release of the therapeutic agent contained therein.

For many polymers, the response to stimuli (for example, swelling) are reversible and repeatable upon additional changes in the external environment. Certain biodegradable polymers are designed to degrade as a result of hydrolysis of the polymer chains into biologically acceptable, and progressively smaller, compounds. For example, with polylactides, polyglycolides, and their copolymers, the polymers will eventually break down to lactic acid and glycolic acid, which then enter the Kreb's cycle (in vertebrates), and are further broken down into carbon dioxide and water. Degradation can occur through bulk hydrolysis, in which the polymer degrades in a fairly uniform manner throughout the matrix, or (for example, with polyanhydrides and polyorthoesters) the degradation occurs only at the surface of the polymer, resulting in a release rate that is proportional to the surface area of the polymer exposed.

In the case of ferrogels, typically micron sized magnetic particles of Fe3O4are dispersed in a polyvinyl alcohol (PVA) hydrogel. The multiferroic ferrogel combines the elastic properties of PVA gel and the magnetic properties of iron. The ferrogel contorts based on application of magnetic field, and can be controlled by the Fe3O4concentration and magnetic field strength. Thus, such ferrogel systems are useful for “on-off” type transducers (for example, for the one or more controllable ports). See, for example, Ramanujan and Lao, Smart Mat. Struct.; Vol. 15, pp. 952-956 (2006), which is incorporated herein by reference.

In an embodiment, the composition is coated, for example, with at least one of dextran sulfate, casein, whey protein, or saccharide.

In an embodiment, the resin is in the form of at leak one of beads, powder, or fiber. In an embodiment, the resin is in the form of particles having a diameter of at least about 1 nm, at least about 5 nm, at least about 10 nm, at least about 20 nm, at least about 30 nm, at least about 40 nm, at least about 50 nm, at least about 60 nm, at least about 70 nm, at least about 80 nm, at least about 90 nm, at least about 100 nm, at least about 150 nm, at least about 200 nm, at least about 300 nm, at least about 400 nm, at least about 500 nm, at least about 600 nm, at least about 700 nm, at least about 800 nm, at least about 900 nm, at least about 1 μm, at least about 10 μm, at least about 20 μm, at least about 30 μm, at least about 40 μm, at least about 50 μm, at least about 60 μm, at least about 70 μm, at least about 80 μm, at least about 90 μm, at least about 1 mm, at least about 5 mm, at least about 10 mm, at least about 20 mm, at least about 30 mm, at least about 40 mm, at least about 50 mm, at least about 100 mm, or any value therebetween or greater.

In an embodiment, the resin suitable for removing at least one ion (e.g., sodium, potassium, calcium, etc.) are present in aqueous solution at a concentration of at least about 10 ppm, at least about 20 ppm, at least about 30 ppm, at least about 40 ppm, at least about 50 ppm, at least about 60 ppm, at least about 70 ppm, at least about 80 ppm, at least about 90 ppm, at least about 100 ppm, at least about 150 ppm, at least about 200 ppm, at least about 250 ppm, at least about 300 ppm, at least about 350 ppm, at least about 400 ppm, at least about 450 ppm, at least about 500 ppm, at least about 550 ppm, at least about 600 ppm, at least about 650 ppm, at least about 700 ppm, at least about 750 ppm, at least about 8000 ppm, at least about 850 ppm, at least about 900 ppm, at least about 950 ppm, at least about 1000 ppm, at least about 1100 ppm, at least about 1200 ppm, at least about 1300 ppm, at least about 1400 ppm, at least about 1500 ppm, at least about 1600 ppm, at least about 1700 ppm, at least about 1800 ppm, at least about 1900 ppm, at least about 2000 ppm, at least about 2100 ppm, at least about 2200 ppm, at least about 2300 ppm, at least about 2400 ppm, at least about 2500 ppm, at least about 2600 ppm, at least about 2700 ppm, at least about 2800 ppm, at least about 2900 ppm, at least about 3000 ppm, at least about 3100 pm, at least about 3200 ppm, at least about 3300 ppm, at least about 3400 ppm, at least about 3500 ppm, at least about 3600 ppm, at least about 3700 ppm, at least about 3800 ppm, at least about 3900 ppm, at least about 4000 ppm, or any value therebetween or greater.

In an embodiment, the resin is suitable for use with an aqueous solution having a pH at about 1, at about 2, at about 3, at about 4, at about 5, at about 6, at about 7, at about 8, at about 9, at about 10, or any value therebetween.

In an embodiment, the porosity of the resin includes pores of about 0 to about 500 Å in diameter; or about 0 to about 500 m2/g.

In an embodiment, for example, a resin (R) has a greater affinity for ion B than for ion A. If the resin contains ion A and ion B is dissolved in the water or other aqueous fluid passing through it, then the ion exchange reaction occurs (proceeding to the right):
AR+Bn+/−BR+An+/−

In an embodiment, a resin in an environment with pH values above at least 3.5, allows divalent ions (e.g., calcium) to enter the resin in amounts greater than those characteristic of monovalent ions. In an embodiment, among monovalent ions, however, there may be variable affinity of the resin for the various positively charged ions (e.g., dependent on the atomic weight, valence, size of the ion, etc.) and can be modified by the degree of resin swelling, nature of the housing, nature of the solvent, pH of the suspension, and the concentrations of the various ions competing for a position on the resin. See, for example, Friedman et al.; Arch. Intern Med.; Vol. 89 (1), pp. 99-106 (1952), which is incorporated herein by reference.

Methods of making the disclosed resin compositions may be conducted in a particular sequence, depending on the components of the composition, or the desired qualities of the composition. For example, in an embodiment a coating includes a crosslinked polymer. In certain instances, the polymer is crosslinked during the polymerization reaction, and in other instances the monomer(s) are polymerized and then the resulting polymer is subsequently treated with a crosslinking agent to form the crosslinked polymer. Likewise, in an embodiment, the polymer coating is prepared prior to combining with the internal resin. In an embodiment, the uncrosslinked polymer is coated on the resin prior to the coating being treated with the crosslinking agent to form the crosslinked polymer.

As described herein, in an embodiment the housing includes at least one polymeric coating. In an embodiment, the compositions disclosed herein further include at least one enteric coating or binding materials to reduce reactivity with the resin at the low pH of the stomach, and instead allow for highest reactivity to occur in the intestinal tract.

As described herein, in an embodiment the housing is configured to regulate access of ion solutes to the internal resin. For example, in an embodiment, the permeability of the housing to divalent cations decreases by reducing the porosity of the housing. In an embodiment, incorporating positive charges into the housing that create electrostatic repulsion with the multivalent cations also reduces access to the resin. In an embodiment, a target ion is desired to be bound to the composition, and a competing ion is an ion that competes with the target ion for the binding capacity of the resin. In an embodiment, the resin includes binding characteristics or permeability characteristics that favor the target ion(s). In an embodiment, a competing ion is prevented from contacting or binding the resin due to at least one of preferential binding characteristics of the resin, decreased permeability of the housing for the competing ion, or other factors. In an embodiment, the housing is permeable to both monovalen and divalent cations. In an embodiment, the housing is permeable to only one of monovalent or divalent cations, but not both. In an embodiment, the housing has a reduced permeability to higher valency cations (e.g., by changing the porosity, average pore size, charge density, or hydrophobicity of the housing, etc.). For example, magnesium and calcium hydrated ions are larger in size compared with monovalent cations such as potassium and sodium. See U.S. Pat. No. 7,556,799, which is incorporated herein by reference.

In an embodiment, the hydrophobicity of the resin causes a reduced interaction with particular cations, and can be altered depending on the target ion(s) and competing ion(s). In an embodiment, the resin has polymers embedded within it that can swell and decrease access to the resin itself (thereby limiting access for binding), which can be regulated by pH, hydrophobicity, crosslinking density, charge density, or solvent ionic strength. In an embodiment, the pH regulates the access or binding of ions to the resin. For example, the binding capacity of the resin can be adjusted such that it has a low binding capacity at gastric pH (e.g., about 3.5, or lower), and a higher binding capacity at the pH of the intestinal tract (e.g., about 5 or higher).

In an embodiment, the access or binding capacity of the resin or coating is further regulated by residence time in the gastro-intestinal tract. For example, in an embodiment, the composition(s) disclosed herein include one or more cell surface molecules (e.g., adhesion molecules) that are formulated to bind to one or more cells in the gastro-intestinal tract during transit through the gut, and extend the residence time (thus, allowing for temporal regulation of uptake of the target ion(s) or allowing for additional uptake of ion(s)).

In an embodiment, at least one of the housing or the resin is permeable or has another selectivity mode through passive absorption while passing through at least part of the gastro-intestinal tract. For example, many soluble materials are charged and are hydrophobic (e.g., due to fatty acid composition, amino acid composition, or other components). In an embodiment, the selectivity of at least one of the housing or the resin is modulated by at least one enzyme of the gastro-intestinal tract. For example, enzymes such as collagenase, neuraminidase, deoxyribonuclease, heparinase, proteinase, lipase, and other enzymes are found in various locations along the gastro-intestinal tract. In an embodiment, at least one enzyme modulates the selectivity of the housing or resin by, for example, cleaving hydrophilic moieties from the hydrophobic backbone of at least one component of the composition.

In an embodiment, the housing is joined to the resin (e.g., physically, chemically, magnetically, electrically, etc.).

In an embodiment, a method of modulating at least one ion in a biological tissue, comprises providing a composition to a biological tissue, the composition including a housing including at least one ingestible resin and one or more controllable ports. In an embodiment, the at least one ingestible resin includes at least one of an anion exchange resin or cation exchange resin. In an embodiment, the biological tissue is located in a biological subject. In an embodiment, the biological subject is a vertebrate or invertebrate. In an embodiment, the biological subject is a plant. In an embodiment, the method further comprises monitoring at least one ion in a biological sample prior to, during, or subsequent to providing the composition including at least in ingestible resin and one or more controllable ports to the biological tissue. In an embodiment, the biological sample includes at least one biological tissue or biological fluid. In an embodiment, the at least one ion includes at least one of wherein the one or more ions include at least one of sodium, potassium, ammonium, magnesium, iron, lithium, or calcium.

In an embodiment, a method of modulating at least one ion in a biological tissue, comprises providing a composition to a biological tissue, the composition including at least one ingestible resin and one or more cell surface molecules. In an embodiment, the biological tissue is located in a biological subject.

In an embodiment, a foodstuff, comprises an ingestible food product including at least one ion exchange resin. For example, in an embodiment, the ingestible food product includes at least one of plant or animal matter. In an embodiment, the ingestible food product includes at least one processed food product. In an embodiment, the ingestible food product includes at least one of milk, soup, dairy products, grain products, fruit products, or vegetable products. In an embodiment, the ingestible food product includes a beverage (e.g., water, milk, soft drinks, juice, etc.). In an embodiment, the ingestible food product includes animal feed (e.g., grain, etc.).

In an embodiment, an article of manufacture comprises an article including a composition having an ingestible resin and one or more cell surface molecules. In an embodiment, an article of manufacture comprises an article including a composition having a housing with one or more controllable ports, and at least one ingestible resin. In an embodiment, the article includes at least one of gum, pacifier; food dish or food dish cover; condiment container, utensil or utensil cover, dental implant; dental accessory; or paper product. In an embodiment, the paper product includes at least one paper packet. In an embodiment, the condiment container is in the form of a condiment packet. In an embodiment, the condiment container is in the form of a condiment bottle. In an embodiment, the condiment container includes at least one of a salt or pepper container. In an embodiment, the article is at least one of reusable or disposable. In an embodiment, the article is configured to maintain the composition in an anhydrous form. In an embodiment, the article includes multiple different ingestible resins.

As indicated in theFIG. 1, in an embodiment, a composition200includes a housing100, including at least one ingestible resin120, and one or more controllable ports130. In an embodiment, the housing100is in the form of a container110(e.g., condiment container that also contains one or more ions140, which in certain instances, include one or more target ions). As illustrated inFIG. 1, in an embodiment, a container110includes one or more controllable ports by which the resin is able to be accessed (e.g., by shaking onto a foodstuff and then ingested by a biological subject). In an embodiment, the composition200includes one or more resins125external to the housing100. In an embodiment, the composition200includes one or more cell surface molecules160(e.g., an adhesion molecule or antibody or portion thereof). In an embodiment, the one or more cell surface molecules160are located external to the housing100. In an embodiment, the one or more cell surface molecules160are located internal to the housing100. In an embodiment, the composition includes at least one sensor150.

As indicated inFIG. 2, in an embodiment, a composition200, includes a housing202including at least one resin205. In an embodiment, the composition includes one or more controllable ports225. In an embodiment, at least one controllable output mechanism235is operably linked to the one or more controllable ports225to control dispensing of at least a portion of the at least one composition200.

In an embodiment, the composition further comprises at least one control circuitry240configured to generate and transmit an electromagnetic control signal configured to control the at least one controllable output mechanism235. In an embodiment, the composition further comprises a transducer270. In an embodiment, the composition further comprises a transmitter260. In an embodiment, the composition200further comprises a receiver280. In an embodiment, the composition200further comprises a power source210.

In an embodiment, the composition200further comprises at least one detection material290. In an embodiment, the detection material290includes at least one of a taggant, contrast agent, sensor270, or electronic identification device. In an embodiment, the delivery device further comprises a controller285configured to respond to the at least one sensor270. In an embodiment, the composition200further comprises a memory mechanism245for storing instructions for generating and transmitting an electromagnetic control signal. In an embodiment, the composition200further comprises at least one memory location255for recording information. In an embodiment, the composition further comprises an information transmission mechanism278configured to transmit information recorded by the at least one electronic memory location.

The following Examples are intended to be illustrative of various embodiments, and are non-limiting in any way.

PROPHETIC EXAMPLES

Enclosed Compositions Including Controlled Ports Containing an Ion Exchange Resin to Sequester Sodium Ions Until They are Eliminated by Excretion

A subject with vascular hypertension is advised to reduce his uptake of sodium ions. The subject adds enclosed compositions containing a cation exchange resin to his food prior to eating. After ingestion the enclosed compositions traverse the gastrointestinal tract until they bind to mucosal receptors in the small intestine where controlled ports selectively allow sodium ions, present in the intestinal fluid, to reach and bind the cation exchange resin inside the enclosed compositions. The enclosed compositions with bound sodium ions are retained in the small intestine until their ion exchange resin is saturated with sodium ions and they are released and excreted.

Enclosed compositions are constructed with reservoirs, ion exchange resins, ion selective membranes and surface molecules that adhere to the mucosa of the small intestine. They are fabricated from silicon dioxide wafers (p-type) using photolithography, etching, and deposition to contain reservoirs that are capped with a sodium ion selective membrane. Enclosed compositions with a thickness of approximately 0.2-0.5 mm and lengths and widths of approximately 1.0-3.0 mm are fabricated with reservoirs that hold approximately 0.50 μl of liquid.

Particular aspects of specific methods to fabricate controlled release compositions with reservoirs are described. See e.g., Ahmed et al.,Journal of Controlled Release81: 291-306, 2002, which is incorporated herein by reference. Similarly, sequential steps of low pressure chemical vapor deposition may be used to layer poly-silicon and low temperature oxide on a silicon wafer for the enclosed compositions of the present disclosure. Next, reservoirs are created by positive photolithography and reactive ion etching. The reservoirs are then filled with a sodium polystyrene sulfonate strong acid cation exchange resin (See e.g., Product Data Sheet for Purolite C100NaMR available from The Purolite Company, Bala Cynwyd, Pa.; which is included herein by reference). The cation exchange resin is then treated with 4 N HCl to obtain the H+form of the resin and then a microinjection apparatus is used to fill the reservoirs with approximately 0.5 mg of resin particles (See e.g., Ahmed et al.,Ibid. for microinjection methods).

The enclosed composition reservoirs are capped with a membrane containing a sodium ion ionophore to enclose the ion exchange resin and to provide controlled ports that selectively allow sodium ions access to the reservoir. For example a sodium selective membrane is made with sodium ionophore, X (tert-butylcalix[4]arene tetraethyl ester)(10 mmol/kg), polyvinyl chloride (33 wt %), bis(2-ethylhexyl) sebacate (DOS) (66 wt %), and sodium tetrakis [3.5bis(trifluoromethyl)phenyl] borate (NaTFPB)(0.3 mmol/kg) dissolved in cyclohexanone and dichloromethane. All chemicals are available from Fluka, Milwaukee, Wis. The ionophore/polymer solution may be spin coated onto the enclosed compositions and the solvent is evaporated at room temperature. Methods to make ion selective membranes are described. See e.g., U.S. Pat. No. 7,651,858, which is incorporated herein by reference. The enclosed compositions are targeted to the small intestine by conjugating a protein, tomato lectin (Lycopersicon esculentum), which binds carbohydrate moieties present in the mucosa lining the small intestine. The enclosed compositions are treated with HCl and H2O2to make them hydrophilic, and then silanized prior to conjugating tomato plant lectin to the surfaces of the enclosed compositions. Methods to conjugate tomato plant lectin (available from Sigma-Aldrich, St. Louis, Mo.) to the silicon surface have been published. See e.g., Ahmed et al.,Ibid.

In order to reduce salt uptake, the subject ingests enclosed compositions containing ion exchange resins behind a sodium selective membrane. Ordinary diets provide an average daily intake of approximately 100 to 300 meq of sodium, and to reduce sodium uptake the subject may require approximately 5 gm to 50 gm of a cation ion exchange resin (see e.g., Greenman et al.,J. Clin. Invest.30: 1027-1031, 1951, and Spencer et al.,Brit. Med.11: 603-606, 1954, each of which are incorporated herein by reference). Each enclosed composition contains approximately 0.5 mg of ion exchange resin, and thus approximately 104to 105enclosed compositions are required. The enclosed compositions containing ion exchange resin may be taken daily for intervals of approximately 3 to 12 days (see e.g., Danowski et al.,Ann. Internal Med.35: 529-541, 1951, which is incorporated herein by reference). The ingested enclosed compositions pass through the stomach and adhere to the mucosa of the small intestine by binding N-acetylglucosamine moieties through tomato lectin which is immobilized on the surface of the enclosed compositions. The enclosed compositions remain in the small intestine and sequester sodium ions that pass from the intestinal fluids through the sodium ion selective membrane and bind the ion exchange resin. The enclosed compositions are left in the small intestine for approximately 3-12 days or until the ion exchange resin has bound the maximum amount of sodium ion (see e.g., Spencer et al.,Ibid.). The enclosed compositions may be released from the small intestine by ingestion of N-acetylglucosamine which competes with intestinal mucosa for binding to tomato lectin immobilized on the enclosed compositions. N-acetylglucosamine is available as a Chitin Hydrolysate from Vector Labs, Inc., Burlingame, Calif. (See e.g., Vector Labs Product Data Sheet: Chitin Hydrolysate which is incorporated herein by reference). The subject is monitored with respect to his blood pressure, plasma sodium ion concentration and stool sodium ion concentration. Assays for these parameters are described, for example, in Spencer et al.,Ibid.

An Ingestible Enclosed Composition with Controllable Ports Containing an Ion Exchange Resin

A subject with congestive heart failure is advised to control his intake of sodium ions. The subject controls salt consumption by limiting salt in his diet and by adding enclosed compositions containing ion exchange resin to his food. The enclosed compositions have ports controlled remotely by an alternating magnetic field (AMF) and they are closed once sodium ions have been sequestered by the ion exchange resin within the enclosed compositions. The sequestered sodium ions are retained in the enclosed composition and excreted via the bowels. Once the enclosed compositions are ingested, the controllable ports can be opened by externally applying an AMF to the small intestine or other sites in the gastrointestinal tract.

Enclosed compositions containing ion exchange resins are constructed to selectively sequester sodium ions and eliminate them when the enclosed compositions are excreted. Enclosed compositions are constructed with reservoirs, ion exchange resins, and controllable ports. The enclosed compositions are fabricated from silicon dioxide wafers (p-type) using photolithography, etching, and deposition to contain reservoirs that are capped with a membrane containing controllable pores. Enclosed compositions with a thickness of approximately 0.2-0.5 mm, and lengths and widths of approximately 1.0-3.0 mm, are fabricated with reservoirs that hold approximately 0.50 μl of liquid. Particular aspects of a specific method to fabricate controlled release compositions with reservoirs are described. See e.g., Ahmed et al.,Journal of Controlled Release81: 291-306, 2002 and U.S. Pat. No. 6,123,861, each of which is incorporated herein by reference.

For example, the enclosed compositions of the instant disclosure are made by sequential steps of low pressure chemical vapor deposition used to layer poly-silicon and low temperature oxide on a silicon wafer. Next, reservoirs are created by positive photolithography and reactive ion etching. Next, the reservoirs are filled with a sodium polystyrene sulfonate strong acid cation exchange resin. (See e.g., Product Data Sheet: “Purolite C100NaMR” available from The Purolite Company, Bala Cynwyd, Pa.; which is included herein by reference). The cation exchange resin is treated with 4 N HCl to obtain the H+form of the resin, and then a microinjection apparatus is used to fill the reservoirs with approximately 0.5 mg of resin particles (See e.g., Ahmed et al.,Ibid. for microinjection methods).

The enclosed composition reservoirs are capped with a thermoswitchable polymer membrane that responds to temperature changes by closing the ports present in the polymer membrane. Thermoswitchable polymer membranes that respond to temperature have been published (see e.g., International Publication No. WO2008/012725, which is incorporated herein by reference). Thermoswitchable polymers exhibit a critical solution temperature. The critical solution temperature is the temperature at which the polymer displays a phase transition from an extended and soluble conformation to a globular collapsed and insoluble conformation. In the extended conformation, the polymer chains are fully solvated, leaving an open and permeable structure, whereas in the collapsed state the polymer structure becomes relatively impermeable. Thermoswitchable polymers include poly-N-isopropylamide (poly-PNIPAAm) and copolymers thereof, polyoxyethylene trimethylol-propane distearate and poly-E-caprolactone. The critical solution temperature may be determined by measuring the polymer volume as a function of temperature. Polymers that display a phase transition upon a decrease of the temperature exhibit an upper critical solution temperature (UCST).

For example, a copolymer of N-isopropylamide and acrylamide exhibits a phase transition from an extended conformation to a collapsed insoluble conformation when the temperature falls below the upper critical solution temperature (UCST). The polymer mesh size and phase transition temperature response can be tailored by adjusting the composition of the monomer, comonomer, and crosslinkers. For example incorporating a hydrophilic comonomer like acrylamide can alter the critical solution temperature. A polymer membrane with an ucst equal to approximately 42° C. is used to cap the enclosed composition reservoirs and to provide controllable ports that restrict solvent access to the ion exchange resin contained in the reservoirs. The controlled ports in the polymer membrane will be closed at normal body temperature, approximately 37° C. and opened when the polymer membrane is heated to 42° C.

To allow remote control of the temperature of the thermoswitchable polymer membranes, they are constructed with superparamagnetic Fe3O4nanoparticles that generate heat when a high frequency alternating magnetic field (AMF) is applied. Methods and materials to construct thermoswitchable polymers containing Fe3O4nanoparticles are described. See e.g., Satarkar and Hilt,J. Control. Rel.130: 246-251, 2008, which is incorporated herein by reference. For example, polymers may be synthesized with NIPPAAm as monomer and Tetra (ethyleneglycol) dimethacrylate (TEGDMA) as crosslinker by redox polymerization (chemicals available at Polysciences, Inc., Warrington, Pa.). Fe3O4nanoparticles, approximately 5% (wt/wt) (available from Nanostructured and Amorphous Materials Inc., Houston, Tex.) are added to the NIPPAAm and TEGDMA polymer components and dispersed by sonication. Thermoswitchable polymer membranes containing 5% Fe3O4are heated by application of an AMF of 5.3 kA/m (strength) and 297 kHz (frequency) to their critical solution temperature and a phase transition. Increasing the percentage of Fe3O4nanoparticles in the membranes increases the amount of heat produced following application of an AMF.

The subject ingests enclosed compositions containing ion exchange resin with his food, prior to meal time, or subsequent to meal time. Approximately 5,000 enclosed compositions are ingested to provide approximately 5 grams of ion exchange resin. The enclosed compositions have reservoirs capped with a thermoswitchable polymer membrane containing Fe3O4that allows heating of the caps by applying high frequency AMF. The polymer membrane caps have an upper critical solution temperature of 42° C. When the caps are at less than 42° C. the polymer is collapsed and impermeable with ports closed. This corresponds to normal body temperature, 37° C.

Approximately 2-3 hours after ingestion of the enclosed compositions the patient's abdominal region is exposed to an AMF that heats the Fe3O4 nanoparticles to approximately 42° C. and results in opening of the ports on the caps to allow intestinal fluid, including sodium ions, access to the reservoirs and the ion exchange resin. The AMF is applied for approximately 30 minutes to allow sodium ions to enter the reservoir and bind the ion exchange resin. Next, the AMF field is removed, and the ports close leaving reservoirs filled with sodium ions that are excreted along with the enclosed compositions.