Oxygen-generating devices and methods

Abstract

Oxygen-generating devices that include a scaffold and a power transfer unit, or a scaffold and an onboard power source. The scaffold may include an electrode and a counter electrode formed of the one or more conductive materials. The electrode may be a non-planar counter electrode. The power transfer unit may receive power wirelessly from a power source, such as an external power source. The power provided by an onboard power source or received by a power transfer unit may produce an electric current with the electrode and the counter electrode, and the electric current may be effective to generate oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold. Methods of treatment and methods of culturing.

Description

MIT 24650 PCT Attorney Docket No. 17648-0331OXYGEN-GENERATING DEVICES AND METHODSCross-reference to Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 762,587, filed February 24, 2025, which is incorporated by reference herein.Field of the Disclosure

[0002] This disclosure relates to oxygen-generating devices, including regenerative medical devices for cell restoration or cell therapy, and methods of culturing and treatment.Background

[0003] Oxygen supply is important for islet cell therapeutics. Electrochemical oxygen generation can supply oxygen in physiological conditions, and can provide implantable and active control features (see, e.g., Paez-Mayorga, J. et al. Nat. Commun. 2022, 13, 7951; and PNAS 2023, 120, e2311707120). Cell scaffolds may be used in vivo for the restoration and reconstruction of complex organs and functional tissues (see, e.g., Wang. A. et al. Nat.Commun. 2021, 12 (1), 5846).

[0004] Typically, 3D cell cultures more closely resemble native organs regarding one or more parameters, such as gene and protein expression, metabolic function, and microscale tissue architecture (see, e.g., Ravi, M. et al. J. Cell. Physiol. 2015, 230 (1), 16-26). However, these systems can be vulnerable to undersupply of oxygen, especially in core areas of cells, typically due to a lack of blood vessels, which can lead to cell death, and can limit long-term cell growth (see, e.g., Lai, B. F. L. et al. Nat. Protoc. 2021, 16 (4), 2158-2189).

[0005] The relevant devices typically include electrodes, which provide electrochemical oxygen, but most, if not all. electrodes are 2D electrodes, which struggle to provide a sufficient oxygen supply, due, for instance, to limited oxygen diffusion, especially when a multi-layer seeding method is employed. And, if a monolayer seeding method is employed, then the size of the devices must increase, which can make implantation difficult or undesirable.

[0006] For example, many apparatuses include (i) a chamber configured to host a volume of cells, e g., islets, and (ii) a planar electrode, which, due to its shape, is usually adjacent only one layer of the cells, e.g., islets. This configuration can be disadvantageous because, for example, oxygen supply is crucial for the insulin secretion function of islets, and the oxygen diffusion barrier typically does not exceed a distance of 100 micrometers, which is often comparable to, or shorter than, the diameter of a single islet (see, e.g.. Place, T.L. etMIT 24650 PCT Attorney Docket No. 17648-0331al. Free Radic. Biol. Med. 2017, 113, 311). As a result, when islets are densely packed in a chamber with a planar electrode arranged at the bottom of the chamber, typically only the lowest layer of islets, which is directly adjacent the electrode, receives adequate oxygen. Adequate oxygen usually is not received by the upper layers of islets, which can lead to hypoxia and reduced functionality .

[0007] Several configurations have been developed with features that attempt to address these disadvantages, such as devices that include oxygen gas chambers and / or exogenous oxygen-supplying tubes (see, e.g., Desai, T. et al. Nat. Rev. Drug Discov. 2017, 16 (5), 338-350; Barkai, U. et al. Cell Transplant. 2013, 22 (8), 1463-1476; and Neufeld, T. et al. PLOS ONE 2013, 8 (8), e70150). To these devices, oxygen is supplied through tubes that extend from the device, which is located inside a patient’s body, to an area outside of the patient’s body. This configuration can be disadvantageous for one or more reasons, such as the fact that the device requires periodic administration of oxygen through the tube, and the exposed tube ty pically impacts the quality of life of patients. The exposed tube, for example, can cause inflammation.

[0008] Other examples of known devices include those disclosed in U.S. Patent No.10,561,763, U.S. Patent Application Publication No. 2021 / 0113736, WO 2022 / 125795A1, and U.S. Patent No. 11,318,106. These devices, however, generate oxygen by consuming materials, including onboard materials, which limits their long-term, chronic applications. Fully-implantable devices have been developed with oxy gen-generating materials, such as calcium dioxide (CaO2), but these approaches have not demonstrated long-term operability' (see, e.g., Pedraza, E. et al. Proc. Natl. Acad. Sci. 2012, 109 (11), 4245-4250). In fact, devices that use oxygen-generating materials, such as CaO2, often provide limited or no control over the rate of oxygen production.

[0009] There remains a need for devices and methods that address one or more of these disadvantages, including fully implantable devices that are configured to generate oxygen, such as devices that generate oxygen electrochemically, thereby providing a sustainable oxygenic environment for cell function and survival.Brief Summary

[0010] Provided herein are devices that may include one or more non-monolayer electrodes, and the devices may be configured to generate oxygen for extended periods, and possibly perpetually, from aqueous biofluids, thereby eliminating the need to supply oxygen to the devices directly via a tube, or produce oxygen by converting a depleting on-boardMIT 24650 PCT Attorney Docket No. 17648-0331oxygen source. Oxygen, for example, may be generated by the devices’ scaffolds via electrochemical processes, such as the electrolysis of aqueous biofluids. Therefore, the scaffolds of the devices, or portions thereof, may provide vasculature-mimicking structural support, thereby fulfilling a role of blood vessels.

[0011] In one aspect, devices are provided. In some embodiments, the devices are biocompatible devices that include a scaffold and a power transfer unit. In some embodiments, the devices are biocompatible devices that include a scaffold and an onboard power source. The scaffold may have a structure formed at least in part of one or more conductive materials. The scaffold may include an electrode and a counter electrode formed of the one or more conductive materials. The electrode may include a non-planar electrode, the counter electrode may include a non-planar counter electrode, or the electrode and the counter electrode may include a non-planar electrode and a non-planar counter electrode, respectively. If the electrode includes a non-planar electrode, then the counter electrode may include a planar counter electrode. If the counter electrode includes a non-planar counter electrode, then the electrode may include a planar electrode. The power transfer unit may be configured to receive power wirelessly from a power source, such as an external power source, to produce an electric current with the electrode and the counter electrode. The onboard power source may provide power to produce an electric current with the electrode and the counter electrode. The electric current may be effective to generate oxygen by electrolysis of an aqueous fluid, such as an aqueous biofluid, in fluid communication with the scaffold.

[0012] In another aspect, methods of treatment are provided. In some embodiments, the methods include providing a biocompatible device, as described herein, wherein a plurality of cells is adsorbed to a scaffold of the device; disposing the oxygen-generating device in or on an organ or a tissue of a patient; and generating oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold. Any amount of oxygen may be generated, such as an amount of oxygen that is effective to prevent or reduce cell death, facilitate cell function, or facilitate cell growth of the plurality of cells.

[0013] In yet another aspect, methods of culturing are provided. In some embodiments, the methods of culturing include providing a device as described herein, particularly a device that includes a plurality of cells adsorbed to a scaffold, and generating oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold. Any amount of oxygen may be generated, such as an amount of oxygen that is effective to prevent or reduce cell death, facilitate cell function, or facilitate cell growth of the plurality of cells.MIT 24650 PCT Attorney Docket No. 17648-0331

[0014] Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described herein. The advantages described herein may be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.Brief Description of the Drawings

[0015] FIG. 1A depicts an embodiment of a non-planar electrode, which includes an embodiment of a spiral structure.

[0016] FIG. IB depicts an embodiment of anon-planar electrode, which includes an embodiment of a plurality of columnar structures extending from a substrate.

[0017] FIG. 1C depicts an embodiment of a non-planar electrode, which includes an embodiment of a branched structure.

[0018] FIG. 2 depicts an embodiment of a device described herein.

[0019] FIG. 3 depicts several components of the device of FIG. 2.

[0020] FIG. 4 depicts a comparative device that includes a planar electrode.

[0021] FIG. 5 depicts an embodiment of a non-planar electrode, which includes an embodiment of a plurality of columnar structures extending through a volume of islets.

[0022] FIG. 6A depicts the baseline insulin secretion of two tested embodiments of devices.

[0023] FIG. 6B depicts the glucose-stimulated insulin secretion of two tested embodiments of the devices.

[0024] FIG. 7A depicts a plot of pH v. voltage for an embodiment of a device.

[0025] FIG. 7B depicts a plot of chlorine concentration v. voltage for an embodiment of a device.

[0026] FIG. 8A depicts the electrochemical activities of an embodiment of oxygengenerating materials that included bare platinum.

[0027] FIG. 8B depicts the electrochemical activities of an embodiment of oxygengenerating materials that included iridium oxide.

[0028] FIG. 8C depicts the electrochemical activities of an embodiment of oxygengenerating materials that included an embodiment of nanostructured platinum.

[0029] FIG. 9 depicts an embodiment of an electrode.MIT 24650 PCT Attorney Docket No. 17648-0331

[0030] FIG. 10 depicts the binding energies for two embodiments of electrode materials.

[0031] FIG. 11 depicts the working cunent of a 2D device and an embodiment of a 3D device described herein.

[0032] FIG. 12A depicts the working currents collected 30 days apart for an embodiment of a 3D device described herein.

[0033] FIG. 12B depicts the oxygen generation rates of an embodiment of a 3D device described herein.

[0034] FIG. 13 depicts a plot of height versus oxygen concentration for a 2D device, and an embodiment of a 3D device.

[0035] FIG. 14 depicts the results of an in-vitro islet function test.

[0036] FIG. 15A depicts an embodiment of an implantable device.

[0037] FIG. 15B depicts an embodiment of an implantable device.Detailed Description

[0038] The devices provided herein may be biocompatible devices. As used herein, the term “biocompatible'’ refers to materials of construction and / or dimensions suitable for use in vivo. (e.g.. as an implantable medical device) and / or in organoid 3D cultures.Scaffold

[0039] The devices described herein may include a scaffold. The scaffold may be formed using any known technique or apparatus, such as 3D printing (e.g., direct writingbased 3D printing of conductive materials), casting (e.g., casting of conductive material(s) in a 3D mold), coating (e.g., electrochemical surface coating on a 3D structure of printed materials), deposition (e.g., vacuum deposition (such as thermal evaporation, e-beam evaporation, sputtering, etc.), electrochemical deposition (such as electroplating), or physical vapor deposition on a 3D structure of printed materials), or a combination thereof. The shape of a scaffold may be configured to provide a structural framework for cell growth; for example, a scaffold may mimic an extracellular matrix. A scaffold may include a substrate, as described herein. A scaffold may be flexible or rigid, or a combination thereof. When a scaffold is characterized herein as a “flexible scaffold”, then the scaffold is formed entirely or partially of a flexible material.

[0040] The scaffold may have a structure formed at least in part of one or more conductive materials. The one or more conductive materials may include flexible materials, rigid materials, or a combination thereof. For example, a scaffold can be formed at least inMIT 24650 PCT Attorney Docket No. 17648-0331part of a metal, which may be present as a coating. A conductive material, such as a metal, may have a surface that is at least partially structured. For example, a conductive material may have a surface, and at least a portion of the surface is modified to have a desired structure. For example, a surface may be nanostructured. A nanostructured surface may be obtained using any known technique, such as electrochemical deposition (e.g., electroplating).

[0041] A conductive material may include one or more layers of different materials, such as different metals, different mixtures of metals, etc. Therefore, components described herein that are formed of one or more conductive materials may include, for example, an inner (e.g., basal) layer of a first conductive material, e.g., a first metal, such as Ga, and a surface or outer layer of a second conductive material, e.g., a second metal, such as Pt. as shown, for example, at FIG.9.

[0042] The one or more conductive materials may include a metal, a non-metal, or a combination thereof. The metal may consist of a single element (e.g., a native metal, a zero valent metal, etc.), or two or more elements. Therefore, the term “metal”, as used herein, reads on and includes alloys and metal-containing compounds, such as metal oxides. Nonlimiting examples of metals include gallium, indium, tin, silver, copper, gold, aluminum, zinc, nickel, iron, platinum, palladium, rhodium, ruthenium, iridium, any oxide thereof, or any combination thereof. Non-limiting examples of non-metal materials include carbon. The one or more conductive materials may be in any physical form, such as a solid, a hydrogel, etc.

[0043] The scaffold may include an electrode and a counter electrode formed of the one or more conductive materials. In some embodiments, the electrode includes a non-planar electrode, (ii) the counter electrode includes anon-planar counter electrode, or (iii) a combination thereof. Therefore, the electrode and the counter electrode may include a non-planar electrode and a non-planar counter electrode, respectively. In some embodiments, the electrode includes a non-planar electrode, and the counter electrode includes a planar counter electrode. In some embodiments, the electrode includes a planar electrode, and the counter electrode includes a non-planar counter electrode. In some embodiments, the electrode includes a planar electrode and the counter electrode includes a planar counter electrode.

[0044] When the term “non-planar” is used herein to characterize an electrode or a counter electrode, the term indicates that (i) the electrode or the counter electrode does not consist of a planar 2D electrode or a planar 2D counter electrode, respectively, such as the planar 2D electrode of FIG.4, which contacts only the first layer 410 of islets 400, asMIT 24650 PCT Attorney Docket No. 17648-0331explained herein, and / or (ii) the electrode or the counter electrode includes at least one elongated structure (e.g.. the electrode of FIG. 3, or the columnar (e.g.. FIG. IB or FIG. 5), spiral (e.g., FIG. 1A), or branched (e.g., FIG. 1C) electrode structures described herein, which may extend from a substrate), at least a portion of which is configured to extend into or through a space featuring a plurality of cells, e.g., islets, arranged at both internal and peripheral regions of the space, thereby permitting the electrode or the counter electrode to contact cells, e.g., islets, positioned at both the internal and the peripheral regions of the space. The elongated structure, in some embodiments, extends from a substrate. The elongated structure, in some embodiments, does not extend from a substrate. When one or more elongated structures extend from a substrate, a longitudinal axis of the one or more elongated structures, independently, may be positioned at any angle relative to a surface of the substrate from which the one or more elongated structures extend, e.g., an angle of about 5 ° to about 90 °, about 15 ° to about 90 °, about 30 ° to about 90 °, about 45 ° to about 90 °, about 60 ° to about 90 °, about 75 ° to about 90 °, or about 85 ° to about 90 °. As used herein, the term "‘spiral’' describes non-linear structures that include a regular or irregular coil and / or regular or irregular curves.

[0045] The elongated structure(s) of a non-planar electrode and / or non-planar counter electrode, independently, may have any dimensions, e.g., length, width, diameter, etc. In some embodiments, the elongated structure(s), independently, have (i) a length and width, independently, of about 0.01 cm toa bout 20 cm, about 0.05 cm to about 20 cm, about 0.05 cm to about 15 cm, about 0.05 cm to about 10 cm, about 0.05 cm to about 5 cm, about 0.05 cm to about 3 cm, about 0.05 cm to about 1 cm, about 0.1 cm to about 20 cm, about 0.1 cm to about 15 cm, about 0.1 cm to about 10 cm, about 0.1 cm to about 5 cm, about 0.1 cm to about 3 cm. about 0.1 cm to about 1 cm, about 0.5 cm to about 20 cm, about 1 cm to about 20 cm, about 1 cm to about 15 cm, about 5 cm to about 15 cm, or about 10 cm to about 15 cm, and (ii) a largest cross-sectional dimension (e.g., diameter) of about 0.1 mm to about 1 mm, about 0.5 mm to about 8 mm, about 0.5 mm to about 7 mm, about 0.5 mm to about 5 mm, or about 3 mm to about 5 mm. When an elongated structure is cylindrical, its width is equal to its largest cross-section dimension. When an elongated structure, for example, has a uniform coiled structure, the ‘‘length” is the distance from one end of the coil to the other end (in its natural state), the “width” is the outer diameter of the coil, and the cross-sectional dimension is the difference between the outer diameter and inner diameter of the coil.

[0046] In some embodiments, a non-planar electrode includes one or more elongated electrode structures extending from a substrate. The substrate may be a planar or non-planarMIT 24650 PCT Attorney Docket No. 17648-0331substrate. The substrate may be formed at least in part of a conductive material, a non-conductive material, or a combination thereof. The one or more elongated electrode structures extending from the substrate generally may have any shape, but, in some embodiments, the one or more elongated electrode structures have at least partially columnar structures, at least partially spiral structures, at least partially branched structures, or a combination thereof. A substrate may have a first surface and an opposing second surface, and the one or more elongated electrode structures may extend from the first surface, the second surface, or the first surface and the second surface. When more than one of the elongated electrode structures extend from a substrate, the elongated electrode structures may be present in a uniform or non-uniform array. An example of an array is depicted at FIG. IB. An array may include any number of elongated electrode structures, such as at least 5, at least 10, at least 20, at least 50, at least 100, or more elongated electrode structures.

[0047] In some embodiments, a non-planar counter electrode includes one or more elongated counter electrode structures extending from a substrate. The substrate may be a planar or non-planar substrate. The substrate may be formed at least in part of a conductive material, a non-conductive material, or a combination thereof. The one or more elongated counter electrode structures extending from the substrate generally may have any shape, but, in some embodiments, the one or more elongated counter electrode structures have at least partially columnar structures, at least partially spiral structures, at least partially branched structures, or a combination thereof. A substrate may have a first surface and an opposing second surface, and the one or more elongated counter electrode structures may extend from the first surface, the second surface, or the first surface and the second surface. When more than one of the elongated counter electrode structures extend from a substrate, the elongated counter electrode structures may be present in a uniform or non-uniform array. An example of an array is depicted at FIG. IB. An array may include any number of elongated counter electrode structures, such as at least 5, at least 10, at least 20, at least 50, at least 100, or more elongated counter electrode structures.

[0048] The columnar structures may be tapered or non-tapered. The columnar structures may have any cross-sectional shape, such as a non-polygonal or polygonal cross-sectional shape. When the cross-sectional shape is circular, the columnar structures may be cylindrical structures, which may be non-tapered or tapered.

[0049] Embodiments of non-planar electrodes are depicted at FIG. 1A, FIG. IB. and FIG. 1C. FIG. 1A depicts an embodiment of a non-planar electrode 10 that includes a spiral structure, which extends through a volume of islets 20. FIG. IB depicts an embodiment of aMIT 24650 PCT Attorney Docket No. 17648-0331non-planar electrode that includes a plurality' of columnar structures 30 extending from a substrate 31, wherein the columnar structures 30 extend through a volume of islets 40. FIG.1C depicts an embodiment of a non-planar electrode that includes an at least partially branched structure 50, which extends through a volume of islets 60.Onboard Power Source

[0050] The devices described herein may include an onboard power source. The onboard power source may include any of those known in the art, such as a battery. The onboard power source may be at least partially encapsulated, as described herein. The onboard power source may be arranged at least partially in a housing, as described herein. Power Transfer Unit

[0051] The devices described herein may include a power transfer unit. The pow er transfer unit may be a commercially available power transfer unit, or the powder transfer unit may be fabricated for use in the devices described herein.

[0052] The power transfer unit may be configured to receive power from a pow er source, such as an external power source, to produce an electric current with the electrode and the counter electrode. The power transfer unit may receive power wirelessly from the power source. As used herein, the phrase '‘external power source” refers to a power source that is not onboard a device, is not physically connected to a power transfer unit by wiring or otherwise, is not implanted in a patient, or a combination thereof.

[0053] The power transfer unit may include a controller, an antenna, a diode, a capacitor, or a combination thereof. These components may be configured to be compatible with the intended use of the device; for example, an antenna may be of a size that does not undesirably impact the ability to dispose the device at a particular location within a patient’s body. The controller, for example, may include a microcontroller unit. The power transfer unit may receive power wirelessly via the antenna by any known mechanism, such as near-field communication (NFC), inducting or resonance coupling of an antenna on board a device and an external antenna, BLUETOOTH® wireless technology', ZIGBEE® wireless protocol, or WI-FI® wireless networking technology, etc.

[0054] An electric current of the devices described herein may be of any magnitude, and may be produced continuously, intermittently, or a combination thereof. In some embodiments, the electric current is effective to generate oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold. The magnitude (amperes) of the electric current may be set or adjusted to modify’ or control a rate of oxygen generation.MIT 24650 PCT Attorney Docket No. 17648-0331

[0055] As used herein, a scaffold and an aqueous fluid are in “fluid communication’' with each other when the scaffold and the aqueous fluid directly contact each other, and / or when an aqueous fluid is at a location that permits electrolysis of the water of the aqueous fluid via the devices described herein.

[0056] The aqueous fluid may include any biofluid. The biofluid may include any one or more biofluids that are continuously provided and / or produced by a patient's body (e.g., plasma, interstitial fluid, etc.), thereby making it possible, at least in some embodiments, to sustain long-term, oxygen-supplied 3D cell cultures.Encapsulation

[0057] The devices described herein also may include an encapsulation material. The devices or any one or more components of the devices (e.g., onboard power source, power transfer unit, scaffold, antenna, etc.) may be partially or fully encapsulated with an encapsulation material. The encapsulation material may serve one or more purposes, including, but not limited to, providing a barrier betw een components of the devices described herein, retaining or controlling the position and / or movement of cells or other molecules within a device, controlling the passage of molecules into and out of a device, imparting a device with an overall shape or physical feature (such as flexibility, permeability, etc.), etc. For example, an encapsulation material may define a chamber or reservoir in which cells are disposed, and at least a portion of an electrode or counter electrode may be arranged in the chamber or reservoir.

[0058] An encapsulation material may have a monolithic structure. For example, an encapsulation material may have a monolithic structure that at least partially encapsulates an electrode (e.g., an oxygen-generating electrode), thereby providing a barrier between the electrode and a counter electrode (e.g., a hydrogen-generating counter electrode). As a further example, an encapsulation material may have a monolithic structure that defines two or more areas, such as a first area in which an electrode (e.g., an oxygen-generating electrode) is disposed, and a second area in which another component of a device is disposed, such as a counter electrode (e.g.. a hydrogen-generating electrode), thereby providing a barrier between the electrode and the counter electrode.

[0059] An encapsulation material may include two or more discrete portions. For example, an encapsulation material may include a first encapsulation material, which at least partially encapsulates one or more components of a device, and a second encapsulation material, which at least partially encapsulates one or more other components of a device. A device, for example, may include an electrode that is at least partially encapsulated with aMIT 24650 PCT Attorney Docket No. 17648-0331first encapsulation material, a counter electrode that is at least partially encapsulated with a second encapsulation material, and a third encapsulation material that at least partially encapsulates all of the components of the device, including the first and second encapsulation materials and the components at least partially encapsulated by the first and second encapsulation materials.

[0060] The encapsulation material may include any known material or combination of materials, and the encapsulation material may be rigid, flexible, or a combination thereof. The encapsulation material may include a permeable material. The permeable material may be a porous material, such as a microporous material, a nanoporous material, etc. For example, an encapsulation material may define pores configured to (i) prevent the passage of relatively larger molecules, such as immunocytes. through the encapsulation material, and (ii) permit the passage of relatively smaller molecules, such as hormones, growth factors, etc. An encapsulation material, or a portion thereof, may include a nanoporous chamber in which an electrode, such as an oxygen-generating electrode, is arranged. In some embodiments, the encapsulation material includes an insulin-permeable nanoporous membrane. In some embodiments, an encapsulation material (i) encapsulates all of the components of a device, (ii) is semi-permeable, (iii) has an average pore size that is less than 3 micrometers, or (iv) a combination thereof.

[0061] An encapsulation material may include a first portion that is permeable and a second portion that is impermeable. The second portion that is impermeable may form a housing having a “window” formed by the first portion that is permeable. An example of such an embodiment is depicted at FIG. 15. As shown at FIG. 15, the components of the device are disposed entirely within the encapsulation device, and the permeable window (which, in the embodiments depicted at FIG. 15, is formed of a cellulose membrane) permits one or more materials, such as an aqueous fluid, to enter and / or exit the encapsulation material.

[0062] The encapsulation material may at least partially define one or more chambers or reservoirs, such as those described herein.Reservoirs

[0063] The devices also may include a reservoir, particularly a reservoir in which byproducts of a chemical reaction are stored, permanently or temporarily. For example, the electrolysis of water produces two products: (i) oxygen gas. which may prevent or reduce cell death, facilitate cell function, or facilitate cell growth of the plurality of cells, and (ii) hydrogen gas, which may be stored in a reservoir of the device, permanently or temporarily.MIT 24650 PCT Attorney Docket No. 17648-0331The reservoirs generally may be of any size or shape, which may be limited only by the overall size of the device.Shape and Dimensions

[0064] A device generally may have any shape and dimensions. The shape and dimensions may be selected in view of a desired site of deployment, an apparatus used to deploy the device, etc. The shape and dimensions of a device may be determined by any one or more components thereof, such as an encapsulation material (see, e.g., FIG. 2), housing (see, e.g., FIG. 15), etc.

[0065] A device, for example, may have an elongated shape, a cube shape, a cuboid shape, etc. The shape may be imparted by an encapsulation material, which, for example, may define a tube-like structure (of any cross-sectional shape), a cube-like structure, a cuboid-like structure, etc. in which the other components of the device are arranged. In some embodiments, the device has (i) an elongated shape, (ii) a length of about 1 cm to about 20 cm, about 1 cm to about 15 cm, about 5 cm to about 15 cm, or about 10 cm to about 15 cm, and (iii) a diameter (cross-section) of about 0.5 mm to about 8 mm. about 0.5 mm to about 7 mm, about 0.5 mm to about 5 mm, or about 3 mm to about 5 mm. In some embodiments, the device has (i) a cube shape, a cuboid shape, etc., (ii) a length, a width, and a height selected, independently, from about 1 cm to about 20 cm, about 1 cm to about 15 cm, about 5 cm to about 15 cm, or about 10 cm to about 15 cm.

[0066] An embodiment of an elongated device is depicted at FIG. 2. The device 100 of FIG. 2 has an elongated shape that is imparted by an encapsulation material 110, which includes an insulin-permeable nanoporous membrane. The device 100 of FIG. 2 also includes a power transfer unit 120, a hydrogen gas reservoir 130, a flexible scaffold 140 that features non-planar electrodes (see FIG. 3) to which islets 150 are adsorbed. The device 100 of FIG. 2 is flexible, as shown in the inset, and has a length 170 of about 10 cm, and a cross-sectional diameter 160 of about 8 mm. The device 100 depicted at FIG. 2 has a circular cross-sectional shape, but other configurations are envisioned.

[0067] FIG. 3 depicts the power transfer unit 120 and the scaffold 140 of the device of FIG. 2. The scaffold 140 includes non-planar electrodes 141, and a non-planar counter electrode 142. The sites of oxygen gas and hydrogen gas generation also are shown. The scaffold of the device of FIG. 2, as shown at FIG. 3, includes elongated 3D electrode structures, which can increase cell function and viability' without a hypoxic environment. Embodiments of the devices described herein, such as the devices depicted at FIG. 2 and FIG. 3, can be loaded into a needle, such as a 6-gauge needle, and injected into the humanMIT 24650 PCT Attorney Docket No. 17648-0331body without surgery. The entire device structure may be formed of an elastomer and semi-permeable membrane, which is capable of its elastic deformation (see inset of FIG. 2).Cells

[0068] The devices described herein also may include a plurality of cells. The plurality7of cells generally may be arranged at any location within the devices. A plurality of cells may be adsorbed to the scaffold.

[0069] The plurality of cells may include any type of cells, such as stem cells, and the cells may be a component of cell clusters (e g., islets), organoids, etc.Methods

[0070] Also provided herein are methods, including methods of treating a patient, and methods of culturing. In some embodiments, the methods include providing a device as described herein, particularly a device that includes a plurality of cells adsorbed to a scaffold.

[0071] As used herein, the term “treatment” refers to alleviating or eliminating a disease or disorder, or reducing or eliminating one or more symptoms of complications of the disease or disorder. The disease or disorder may include a metabolic disease, such as diabetes (Type 1 and Type 2).

[0072] The methods also may include disposing a device in or on a patient. A device is considered to be “in” a patient when the device is embedded at least partially in the patient's skin or arranged at a location beneath the patient’s skin. Non-limiting examples of deployment sites include a subcutaneous region, the omentum, and a region between the skin and pectoralis major. Other sites are envisioned, however, such as other organs or tissues of the patient.

[0073] The disposing of a device in and / or on a patient may include injecting or implanting a device at a location in and / or on a patient, such as an organ and / or a tissue of the patient. A device may be injected using any equipment or apparatus. A device, for example, may be injected using a syringe needle. The ability to inject a device may avoid the need for surgery to deploy the device.

[0074] The methods also may include generating oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold. In some embodiments, the generating of oxygen occurs at a first rate and a second rate, wherein the second rate is measured 30 days, 60 days, 90 days, or 180 days after the first rate, and the second rate has a value equal to at least 90 %, at least 95 %, or at least 99 % of the first rate.

[0075] Any amount of oxygen may be generated by embodiments of the devices described herein. In some embodiments, an amount of oxygen generated is effective toMIT 24650 PCT Attorney Docket No. 17648-0331prevent or reduce cell death, facilitate cell function, or facilitate cell grow th of the plurality of cells.

[0076] All referenced publications are incorporated herein by reference in their entirety . Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[0077] While certain aspects of conventional technologies have been discussed to facilitate disclosure of various embodiments, applicants in no way disclaim these technical aspects, and it is contemplated that the present disclosure may encompass one or more of the conventional technical aspects discussed herein.

[0078] The present disclosure may address one or more of the problems and deficiencies of know n methods and processes. However, it is contemplated that various embodiments may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the present disclosure should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.

[0079] In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.

[0080] In the descriptions provided herein, the terms "‘includes,” “is,” “containing,” “having,” and “comprises” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to.” When devices or methods are claimed or described in terms of “comprising” various steps or components, the devices or methods can also “consist essentially of’ or “consist of' the various steps or components, unless stated otherwise.

[0081] The terms “a,” “an,” and “the” are intended to include plural alternatives, e.g., at least one. For instance, the disclosure of “a scaffold”, “an electrode”, “a biofluid”, and the like, is meant to encompass one, or mixtures or combinations of more than one scaffold, electrode, biofluid, and the like, unless otherwise specified.MIT 24650 PCT Attorney Docket No. 17648-0331

[0082] Various numerical ranges may be disclosed herein. When Applicant discloses or claims a range of any type, Applicant's intent is to disclose or claim individually each possible number that such a range could reasonably encompass, including end points of the range as well as any sub-ranges and combinations of sub-ranges encompassed therein, unless otherwise specified. Moreover, all numerical end points of ranges disclosed herein are approximate. As a representative example, Applicant discloses, in some embodiments, that a device has a length of about 5 cm to about 15 cm. This range should be interpreted as encompassing about 5 cm and about 15 cm, and further encompasses “about” each of 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 11 cm, 12 cm, 13 cm, and 14 cm, including any ranges and subranges between any of these values.

[0083] As used herein, the term “about” means plus or minus 10 % of the numerical value of the number with which it is being used.EXAMPLES

[0084] The present invention is further illustrated by the following examples, which are not to be construed in any way as imposing limitations upon the scope thereof. On the contrary, it is to be clearly understood that resort may be had to various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims. Thus, other aspects of this invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.Example 1 - Comparison of Electrode Structures

[0085] In this example, tests were conducted to compare the functionality’ of seeded islets when different oxygen-generating electrode structures were used.

[0086] The two embodiments of electrode structures tested in this example are depicted at FIG.4 and FIG. 5.

[0087] As shown at FIG. 4, the comparative electrode had a planar structure, which featured a substrate 420 in which contacts 430 were arranged. The contacts 430 had a width of about 80 micrometers, and were separated by’ a distance of 300 micrometers. Due to the planar structure of the comparative electrode of FIG. 4, only the first layer 410 of islets 400 was in close proximity to the contacts 430.

[0088] As shown at FIG. 5, this example tested an embodiment of a device that included a non-planar electrode, as described herein. The non-planar electrode of FIG. 5MIT 24650 PCT Attorney Docket No. 17648-0331included an electrode featuring a plurality of columnar structures 510 that extended from a substrate 520. The columnar structures 510 had a length of about 1 mm (measured from the surface of the substrate 520 to the end of each columnar structure), and extended through the volume of islets 510, unlike the contacts 430 of FIG. 4.

[0089] For comparison purposes, the geometrical density7of islets was consistent between the two electrode structures tested in this example. To evaluate islet functionality, baseline insulin secretion and glucose-stimulated insulin secretion (GSIS) tests were conducted. The results of these tests are depicted at FIG.6A. Since viable and functional islets secrete insulin at baseline levels, the baseline insulin secretion with a controlled number of islets served as an indicator of their functionality and viability.

[0090] GSIS is a physiological process in which islets secrete increased levels of insulin in response to elevated glucose concentrations. High insulin responsiveness to glucose stimulation indicates enhanced islet functionality. When the islets of this example were seeded using the electrode structure of FIG. 5 at a density of 66 IEQS (Isletequivalents ) / mm2, both baseline insulin secretion (FIG. 6A) and GSIS performance (FIG. 6B) were significantly superior compared to the electrode structure of FIG. 4 with the same seeding density7.

[0091] The results of this example demonstrated that the device can provide sufficient oxy gen to support islets at a high functional density of 66 IEQ / mm2or higher.Example 2 - Byproduct Safety on Electrolysis

[0092] Since electrolysis of biofluids at elevated potentials can result in the formation of peroxide ions or chlorine gases, several tests were conducted to assess the safety7of the devices described herein.

[0093] Within the working potential range of the embodiment of the device of Example 1 (FIG. 5), no significant changes in pH or chlorine concentration were observed, as depicted at FIG. 7A and FIG. 7B, respectively.

[0094] Not wishing to be bound by any particular theory7, it was believed that the geometric separation of the hydrogen-generating electrode from the oxygen-generating electrodes and the islet-seeding chamber enhanced the safety of the tested device by mitigating pH fluctuations, preventing the formation of hydrogen bubbles that could mechanically damage the islets, or a combination thereof.

[0095] Additionally, the device operated at a consistent oxygen-generation potential (~1.7 V). which remained below the chlorine-formation threshold (-1.9 V), thereby avoiding chlorine generation.MIT 24650 PCT Attorney Docket No. 17648-0331Example 3 - Material Selection for Oxygen Generation

[0096] The material properties, including electrocatalytic activity, stability, conductivity, and surface characteristics, can facilitate or contribute to effective oxygen generation through electrolysis. To achieve efficient oxygen generation at low potentials, electrocatalytic materials were deposited onto non-planar electrode structures, such as those depicted at FIG. 1A. FIG. IB, and FIG.l C, and their electrochemical performance was evaluated.

[0097] Platinum (Pt) and iridium oxide (IrOx) were selected for testing in this example due to their well-documented high electrocatalytic activities. Platinum was deposited both with and without surface nanostructures, while iridium oxide was deposited exclusively with surface nanostructures.

[0098] Planar materials were deposited by vacuum deposition (e.g. thermal evaporation, e-beam evaporation, or sputtering), and nanostructured materials can be deposited by electrochemical deposition (e.g. electroplating).

[0099] Among the three groups tested in this example, nanostructured platinum exhibited the largest electrochemical surface area and significant surface roughness. This resulted in the highest current density, directly correlating to an increased rate of oxygengeneration reactions. Furthermore, nanostructured platinum demonstrated superior catalytic behavior, as evidenced by the lowest onset potential for starting oxygen generation (1.163 V vs. Ag / AgCl). The results of these tests are depicted at FIG. 8A (bare Pt), FIG. 8B (InOx), and FIG.8C (nanostructure Pt).Example 4 - Property’ of Oxygen Electrodes

[0100] In this example, properties of an embodiment of an oxygen electrode were determined by performing an X-ray photoelectron spectroscopy (XPS) analysis of the electrode depicted at FIG. 9. FIG. 9 depicts an embodiment of an electrode 900 that includes Pt and Ga, and the first and second insets of FIG. 9 depict the structure of the electrode, and the charge density difference of the components.

[0101] FIG. 10 depicts the results of the XPS analysis. The results indicated a synergistic effect of Pt and basal Ga. Not wishing to be bound by any particular theory, it was believed that electron donation from the “bottom” Ga increased charge density' in the thin surface platinum. The increased charged density' may have promoted electron donation to water molecules, thereby resulting in or improving oxygen generation.Example 5 - Further Comparison of 2D and 3D StructuresMIT 24650 PCT Attorney Docket No. 17648-0331

[0102] In this example, oxygen generation rates were calculated for a 2D device and an embodiment of the 3D devices described herein.

[0103] According to the relevant literature, the oxygen consumption rate of an islet is 2.1 pmol / min per single islet equivalent (IEQ) (see, e.g., BioRxiv doi.org / 10.1101 / 2025.04.21.649806). The oxygen generation rates of this example were calculated by the following equation:2>2 7385,940 .wherein I is current (ampere), t is time (seconds), and 1 mol O2 = 22.4 L.

[0104] The results of this example are provided at FIG. 11, which demonstrates that the embodiment of the 3D device of this example generated O2 (mol) at a rate of 6.82 nmol / min (i.e., 6,820 pmol / min), which is sufficient to supply oxygen for 3,247 lEQs.

[0105] This result demonstrates that sufficient oxygen is generated for 3,000 lEQs in the embodiment of the 3D device of this example, which had dimensions of 3 mm * 3 mm * 2 mm.

[0106] Also, in this example, duty cycle tuning resulted in what was believed to be a maximum O2 (mol) generation rate of 9,090 pmol / min, which is sufficient to supply oxygen for 4,328 lEQs in the same device or a device having the same dimensions.Example 6 Test of Long-term Stability (30 days)

[0107] In this example, the long-term stability (30 days) of the 3D device of Example 5 was tested. The oxygen generation rates were calculated from the current values that were collected 30 days apart. The results are depicted at FIG. 12A and FIG. 12B.

[0108] The results indicated that the tested device provided long-term, stable, sufficient oxygen production. Specifically, the current decreased about 3.3 % over a 30 day period, which may be a negligible decrease for most, if not all, applications. After 30 days, the tested device still supplied about 7,000 pmol of oxygen per minute.Example 7 - Oxygen Profiling

[0109] In this example, height-dependent oxygen concentration profiles were collected for the devices of Example 5, which includes a 2D device and an embodiment of a 3D device described herein. An oxygen probe was attached to a precision stage to measure oxygen generation and oxygen saturation (~ 30 minutes) at increasing heights (N = 4).

[0110] The results are depicted at FIG. 13, which demonstrates that the tested 3D electrode provided oxygen, in a substantially uniform manner, throughout the measured 2MIT 24650 PCT Attorney Docket No. 17648-0331mm height, but the oxygen profile in the 2D device decreased as the measurement height increased.Example 8 - Device Functionality - High-throughput Testing[OHl] In this example, all fabrication processes and device performances were confirmed and optimized, and the devices’ oxygen supplies were tested by the functionality of the islets. To facilitate reliable high-throughput testing, systems that connected 12 devices were fabricated, thereby permitting the selective placement or fabrication of 2D or 3D scaffolds in or on the system.Example 9 - In-Vitro Islet Function Test

[0112] In this example, the effect of oxygen generation and electrode structures on islet functionality were tested. The positive control included islets in a normoxic condition, with no gel encapsulation. To observe the effect of electrochemical oxygen generation, the negative control included islets in a non-working device.

[0113] The glucose-stimulated insulin secretion (GSIS) results showed that the 3D device induced an increased GSIS of islets, compared to the 2D device. Also, the tested 3D devices’ oxygen generation performance made its oxygen environment comparative to the normoxic condition. The results are depicted at FIG. 14.Example 10 - Implantable Device

[0114] In this example, an embodiment of an implantable device was constructed for in-vivo applications. The embodiment of the device of this example included an embodiment of a 3D oxygen scaffold, cell chamber, battery, and a power circuit. These components were arranged in a housing having a size comparable to the size 000 capsule. The embodiment of the device of this example, has a cell reservoir area (3 mm * 3 mm) to accommodate 3,000 IEQ seeding for rat in-vivo testing.

[0115] A schematic of the embodiment of the device of this example is depicted at FIG. 15A and FIG. 15B. The device 1500 includes a housing 1510, which is in a closed configuration in FIG. 15A and an open configuration in FIG. 15B to show the internal components. Within the housing 1510 is are a battery and circuit 1520. The device 1500 also includes a cellulose membrane 1530 and an islet reservoir 1540 that includes a 3D electrode, which may have any configuration described herein, such as the configuration depicted at FIG. 1A, FIG. IB, or FIG. 1C

Claims

MIT 24650 PCT Attorney Docket No. 17648-0331We claim -1. A biocompatible oxygen-generating device comprising:a scaffold having a structure formed at least in part of one or more conductive materials, wherein the scaffold comprises an electrode and a counter electrode formed of the one or more conductive materials, and wherein (i) the electrode comprises a non-planar electrode, (ii) the counter electrode comprises a non-planar counter electrode, or (iii) the electrode comprises a non-planar electrode and the counter electrode comprises a non-planar electrode; andan onboard power source configured to provide power, or a power transfer unit configured to receive power wirelessly from a power source, wherein the power provided or received by the onboard power source or the power transfer unit, respectively, produces an electric current with the electrode and the counter electrode;wherein the electric current is effective to generate oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold.

2. The device of claim 1, wherein the non-planar electrode comprises one or more elongated electrode structures extending from a substrate.

3. The device of claim 2, wherein the one or more elongated electrode structures are at least partially columnar structures, at least partially spiral structures, at least partially branched structures, or a combination thereof.

4. The device of claim 1, wherein the non-planar electrode comprises one or more elongated structures,wherein the one or more elongated structures, independently, are at least partially columnar structures, at least partially spiral structures, at least partially branched structures, or a combination thereof, andwherein the one or more elongated structures, independently, have a length of about 0.01 cm to about 20 cm.

5. The device of claim 1, wherein the non-planar counter electrode comprises one or more elongated counter electrode structures extending from a substrate.MIT 24650 PCT Attorney Docket No. 17648-03316. The device of claim 5, wherein the one or more elongated counter electrode structures are at least partially columnar structures, at least partially spiral structures, at least partially branched structures, or a combination thereof.

7. The device of claim 1, wherein the non-planar counter electrode comprises one or more elongated structures,wherein the one or more elongated structures, independently, are at least partially columnar structures, at least partially spiral structures, at least partially branched structures, or a combination thereof, andwherein the one or more elongated structures, independently, have a length of about 0.05 cm to about 20 cm.

8. The device of claim 1, wherein the one or more conductive materials comprises a metal.

9. The device of claim 1, further comprising an encapsulation material.

10. The device of claim 10, wherein the encapsulation material at least partially encapsulates the scaffold to provide a barrier between the electrode and the counter electrode.

11. The device of claim 10, wherein the encapsulation material comprises a nanoporous membrane.

12. The device of claim 1, wherein at least a portion of the scaffold is flexible.

13. The device of claim 1, further comprising a plurality of cells, wherein the plurality of cells is (i) adsorbed to the scaffold, (ii) disposed in a chamber defined by an encapsulation material, or (iii) a combination thereof.

14. A method of treatment, the method comprising:providing the device of any one of claims 1 to 13;disposing the device in or on an organ or a tissue of a patient; andMIT 24650 PCT Attorney Docket No. 17648-0331generating oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold, wherein an amount of oxygen generated is effective to prevent or reduce cell death, facilitate cell function, or facilitate cell growth of the plurality of cells.

15. A method of culturing, the method comprising:providing the device of any one of claims 1 to 13; andgenerating oxygen by electrolysis of an aqueous fluid in fluid communication with the scaffold, wherein an amount of oxygen generated is effective to prevent or reduce cell death, facilitate cell function, or facilitate cell growth of the plurality of cells.

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