WO2018227026A1

WO2018227026A1 - Dialysate regeneration or enhancement component and methods of use thereof

Info

Publication number: WO2018227026A1
Application number: PCT/US2018/036565
Authority: WO
Inventors: Charles C. KLASSEN
Original assignee: Iviva Medical, Inc.
Priority date: 2017-06-07
Filing date: 2018-06-07
Publication date: 2018-12-13

Abstract

Disclosed are compositions and methods of regenerating or enhancing dialysate. Specifically, provided is a dialysate regeneration or enhancement component having a membrane with luminal spaces on each side wherein dialysate is circulated on one side of the membrane and waste dialysate is circulated on the other side. Renal tubule epithelial cells embedded on the membrane transport water, glucose, electrolytes, amino acids and other beneficial compounds from the waste dialysate across a membrane into unused dialysate, thereby reducing the amount of dialysate needed for peritoneal dialysis or enhancing the dialysate.

Description

DIALYSATE REGENERATION OR ENHANCEMENT COMPONENT AND

METHODS OF USE THEREOF

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.

62/516,200, filed on June 7, 2017, the content of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] Peritoneal dialysis (PD) is a type of dialysis that uses the peritoneum in a patient's abdomen as the membrane through which fluid and dissolved substances are exchanged with the blood. PD is used to remove excess fluid, correct electrolyte problems, and remove toxins in those with kidney failure. Continuous Ambulatory Peritoneal Dialysis (CAPD) requires the patient to add and remove dialysate thorough a catheter in the abdomen multiple times per day. During periods when the dialysate is present in the peritoneal cavity, the patient may move about (i.e., ambulate). However, the longer the dialysate is present in the peritoneal cavity, the less effective the dialysate becomes at removing wastes as the dialysate nears equilibrium.

[0003] Automated Peritoneal Dialysis (APD) cycles dialysate in and out of a patient's peritoneal cavity during sleep during set intervals that are usually more frequent than the intervals in CAPD. The benefit of standard APD therapy is the cycling during sleep and subsequent improved clearance rates over 24 hrs when compared to CAPD; however it requires large dialysate reservoirs and a total dialysate volume of 6-12 liters per sleep period (1-2).

[0004] In continuous flow peritoneal dialysis (CFPD), the dialysate is continuously added and removed from the patient's peritoneal cavity, also usually during sleep. CFPD currently requires in excess of 200 liters of dialysate per day, but has proven to be the most effective PD modality (2-7). SUMMARY OF THE INVENTION

[0005] Work described herein demonstrates that by using a membrane having cells on the surface (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells), and separating waste dialysate from fresh dialysate such that a portion of the dialysate can be reused or have an extended period of effectiveness compared to current methods, the total volume of dialysate needed for peritoneal dialysis can be reduced, e.g., from 6-12 liters to 2-3 liters for APD. Work described herein incudes a device and method wherein the native transport function of renal tubule epithelial cells on a membrane is used to selectively transport water, glucose, electrolytes, amino acids and other beneficial compounds from the waste dialysate across a membrane into viable or unused dialysate, thereby vastly reducing the amount of dialysate needed for peritoneal dialysis (e.g., APD). The disclosures herein also enable practical implementation of CFPD by reducing the amount of dialysate to a manageable and economically feasible amount. The dialysate produced by the disclosed device (i.e., enhanced dialysate) comprises compounds not present in fresh dialysate, thereby enhancing the dialysate's utility.

[0006] Some aspects of the disclosure are related to a dialysate regeneration or enhancement component (i.e., dialysate regeneration component, dialysate regeneration or enhancement device, dialysate regeneration device, component, device) comprising a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, the first and second luminal spaces are in fluid communication with each other across the membrane, and the component is configured to fluidly connect the first luminal space to a dialysis supply reservoir and fluidly connect the second luminal space to a waste dialysate reservoir. In some embodiments, the first and second luminal spaces are embedded in a first and second scaffold, respectively. In some embodiments, the first and second scaffolds comprise a polymer or a hydrogel.

[0007] In some embodiments, the first luminal space comprises a first microchannel network in fluid communication with the first surface of the membrane. In some

embodiments, the second luminal space comprises a second microchannel network in fluid communication with the second surface of the membrane. In some embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by 5-100 μΜ. In some embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by 5-10 μΜ. [0008] In some embodiments, the component further comprises a housing configured to connect the component to a dialysate reservoir and a waste dialysate reservoir. In some embodiments, the housing is a sterile tight-fitting plastic housing with barbed connections for connecting to dialysate and waste dialysate channels. In some embodiments, the component further comprises one or more pumps for circulating the dialysate and waste dialysate through the component.

[0009] In some embodiments, the area of membrane across which the first and second luminal spaces are in fluid communication across the membrane is at least 30 cm , at least 60 cm², at least 90 cm², at least 100 cm², at least 150 cm², at least 200 cm², at least 250 cm², at least 300 cm², at least 450 cm², at least 600 cm², at least 800 cm², at least 1000 cm², or at least 1200 cm or more.

[0010] Prior to use, the component may be stored. In some embodiments, the membrane and/or scaffold is stored in dehydrated form. In some embodiments, the component is stored with the membrane and/or scaffold in hydrated form. For example, the component may be stored in a sterile fluid and/or at refrigeration temperatures.

[0011] In some embodiments, the component further comprises cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) on the first surface of the membrane, on the second surface of the membrane, or the first and second surfaces of the membrane. In some embodiments, the cells are at confluence on a membrane surface. In some embodiments, the component comprises at least 2xl0⁶ cells. In some embodiments, the component comprises at least lxlO⁷ cells. In some embodiments, the component comprises at least 2xl0⁷ cells. In some embodiments, the cells are on at least 30 cm², at least 60 cm², at

2 2 2 2 2 least 90 cm , at least 100 cm , at least 150 cm , at least 200 cm , at least 250 cm , at least 300

2 2 2 2 2

cm , at least 450 cm , at least 600 cm , at least 800 cm , at least 1000 cm , or at least 1200 cm² or more of membrane surface. For example, cells can be on 15 cm² of each side of the membrane (i.e., the first and second side of the membrane) for a total of 30 cm² of surface area of the membrane. In some embodiments, the cells are only on the first membrane surface (i.e., the side facing the dialysate). In some embodiments, the cells are only on the second membrane surface (i.e., the side facing the waste dialysate). In some embodiments, the cells are on both membrane surfaces. In some embodiments, the cells are renal tubule epithelial cells. In some embodiments the cells are renal tubule epithelial cells and endothelial cells. For example, the renal tubule epithelial cells can be on one membrane surface and the endothelial cells can be on anther surface. [0012] In some embodiments, the cells are allogenic to a patient using the component. In some embodiments, the cells are autologous to a patient using the component. In some embodiments, the cells are from a cell line. In some embodiments, the cells are autologous stem cell derived cells. In some embodiments, the autologous stem cells are derived from induced pluripotent stem cells.

[0013] Some embodiments comprise a peritoneal dialysis system comprising one or more dialysate regeneration or enhancement components as described herein. In some embodiments, the peritoneal dialysis system comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more dialysate regeneration or enhancement components as described herein. In some

embodiments having greater than one dialysate regeneration or enhancement component, the components are connected in serial or are connected to one or more manifolds that control flow (e.g., equalize flow) of dialysate and/or waste dialysate to the components. In some embodiments, the peritoneal dialysis system is an automated peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is a continuous flow peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is continuous ambulatory peritoneal dialysis system.

[0014] Some aspects of the disclosure are related to a dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is embedded in a first scaffold comprising a polymer or hydrogel and the first luminal space comprises a first microchannel network in fluid communication with the first surface of the membrane, and the second luminal space is embedded in a second scaffold comprising a polymer or hydrogel and the second luminal space comprises a second microchannel network in fluid

communication with the second surface of the membrane, wherein the first and second luminal spaces are separated from each other on opposite sides of the membrane by a width of 5 to 10 μΜ, and wherein the component is configured to fluidly connect the first luminal space to a dialysis supply reservoir and fluidly connect the second luminal space to a waste dialysate reservoir.

[0015] In some embodiments, the component further comprises cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) on the first surface of the membrane, on the second surface of the membrane, or on both the first and second surface of the membrane. In some aspects, the component comprises a housing, an area of membrane across which the first and second luminal spaces are in fluid communication, an amount of cells, a surface area of one or both membrane surfaces covered by cells, and/or a type (e.g., allogenic) of cells as described herein.

[0016] Some embodiments are related to a peritoneal dialysis system comprising the dialysate regeneration or enhancement component described herein. In some embodiments, the peritoneal dialysis system is an automated peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is a continuous flow peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is continuous ambulatory peritoneal dialysis system.

[0017] Some aspects of the disclosure are related to a peritoneal dialysis system comprising a dialysate supply reservoir, a waste dialysate reservoir, and one or more dialysate regeneration or enhancement components, wherein the dialysate regeneration or enhancement component comprises a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, and the first and second luminal spaces are in fluid communication with each other across the membrane; the first luminal space is fluidly connected to the dialysate supply reservoir, thereby enabling circulation of dialysate between the dialysate supply reservoir and the first luminal space; the second luminal space is fluidly connected to the waste dialysate reservoir, thereby enabling circulation of dialysate between the waste dialysate reservoir and the second luminal space; and at least a portion of the first and/or second luminal space in fluid communication with the membrane comprises cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells). In some embodiments, the peritoneal dialysis system further comprises one or more pumps configured to circulate dialysate between the dialysate supply reservoir and the first luminal space and circulate dialysate between the waste dialysate reservoir and the second luminal space. In some embodiments, the peritoneal dialysis system is configured to deliver dialysate to the peritoneal cavity of a patient from the dialysate supply reservoir and configured to remove waste dialysate from the patient's peritoneal cavity.

[0018] In some embodiments, the peritoneal dialysis system comprises one or more pumps and one or more catheters configured to deliver and remove dialysate from a patient's peritoneal cavity. In some embodiments, the dialysate regeneration or enhancement component is a component as described herein. In some embodiments, the peritoneal dialysis system is an automated peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is a continuous flow peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is continuous ambulatory peritoneal dialysis system.

[0019] Some aspects of the disclosure are related to a method of producing cell- enhanced dialysate comprising: providing a source of dialysate, a source of waste dialysate, and a dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space and cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) on the first and/or second surface of the membrane, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, and the first and second luminal spaces are in fluid communication with each other across the membrane; and pumping waste dialysate from the source of waste dialysate through the second luminal space and pumping dialysate from the source of dialysate through the first luminal space, wherein the cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) selectively transport compounds from the waste dialysate across the membrane into the dialysate, thereby producing cell-enhanced dialysate. In some embodiments, the cells selectively transport one or more of water, glucose, electrolytes, amino acids or other beneficial compounds. In some embodiments, the cells selectively transport water, glucose, electrolytes, amino acids and other beneficial compounds.

[0020] In some aspects, the component comprises a housing, an area of membrane across which the first and second luminal spaces are in fluid communication, an amount of cells, a surface area of one or both membrane surfaces covered by cells, and/or a type (e.g., allogenic) of cells as described herein. In some embodiments, the dialysate regeneration or enhancement component is a component as described herein.

[0021] Some aspects of the disclosure are directed to a method of performing peritoneal dialysis comprising: pumping dialysate along a first flow path out of a dialysate supply reservoir into a peritoneal cavity of a subject; pumping waste dialysate along a second flow path out of the peritoneal cavity into a waste dialysate reservoir; pumping waste dialysate along a third flow path out of the waste dialysate reservoir, through a dialysate regeneration or enhancement component comprising a membrane, and back into the waste dialysate reservoir; and pumping dialysate along a fourth flow path out of the dialysate supply reservoir, through the dialysate regeneration component comprising a membrane, and back into the dialysate supply reservoir; wherein the fourth flow path comprises a first luminal space in fluid communication with a first side of the membrane, wherein the third flow path comprises a second luminal space comprising cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) that are in fluid communication with a second side of the membrane, and wherein the cells transport compounds from waste dialysate in the third flow path across the membrane into dialysate in the fourth flow path. In some embodiments, the cells selectively transport one or more of water, glucose, electrolytes, amino acids or other beneficial compounds. In some embodiments, the cells selectively transport water, glucose, electrolytes, amino acids and other beneficial compounds.

[0022] In some embodiments, the peritoneal dialysis system comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more dialysate regeneration or enhancement components as described herein. In some embodiments having greater than one dialysate regeneration or enhancement component, the components are connected in serial or are connected to one or more manifolds that control flow (e.g., equalize flow) of dialysate and/or waste dialysate to the components. In some aspects, the component comprises a housing, an area of membrane across which the first and second luminal spaces are in fluid communication, an amount of cells, a surface area of one or both membrane surfaces covered by cells, and/or a type (e.g., allogenic) of cells as described herein. In some embodiments, the dialysate regeneration or enhancement component is a dialysate regeneration or enhancement component described herein.

[0023] The above discussed, and many other features and attendant advantages of the present inventions will become better understood by reference to the following figures and detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

[0025] FIG. 1 shows an embodiment of the dialysate regeneration or enhancement component (e.g., dialysate regeneration or enhancement device) with a membrane, having on the surface thereof, cells (i.e., a living membrane). The component includes a lumen for waste dialysate (e.g., PD effluent dialysate) in yellow, a lumen for fresh dialysate in blue, membranes separating the waste and fresh dialysate comprising cells, a scaffold block or housing, as well as input and output ports for waste and fresh dialysate.

[0026] FIG. 2 shows an example of an Automated Peritoneal Dialysis (APD) method with cell-enhanced dialysate (CPD) (i.e., enhanced dialysate). The CPD device is a dialysate regeneration or enhancement component as described herein. Waste or effluent dialysate from the patient (yellow) is pumped through the component. Cells in the component transport various compounds from the waste dialysate to the fresh dialysate (blue), thereby creating cell-enhanced dialysate. A pump then circulates the enhanced dialysate back to the dialysate reservoir for administration to the patient.

[0027] FIG. 3 shows a membrane interposed between a lumen containing waste dialysate and fresh dialysate. Cells on the membrane (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) selectively transport water, glucose, electrolytes, amino acids, bicarbonate, sodium, vitamins, calcium, chloride, magnesium and other beneficial compounds from the waste dialysate to the fresh dialysate.

[0028] FIGS. 4A and 4B show standard continuous flow peritoneal dialysis (CFPD) (4A) and CFPD with a dialysate regeneration or enhancement component as described herein (4B) transporting beneficial compounds and water from the waste dialysate reservoir into the fresh dialysate reservoir, creating enhanced dialysate.

[0029] FIG. 5 shows a cross-sectional view of a dialysate regeneration or

enhancement component as described herein. Lumens having waste dialysate and lined with cells are shown in yellow. Lumens having fresh dialysate and lined with cells are shown in blue. The lumens are embedded in a scaffold with membranes indicated by lines separating the waste dialysate and fresh dialysate lumens.

DETAILED DESCRIPTION OF THE INVENTION

[0030] Some aspects of the disclosure are related to a dialysate regeneration or enhancement component (i.e., dialysate regeneration component, dialysate regeneration or enhancement device, dialysate regeneration device, component, device) comprising a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, the first and second luminal spaces are in fluid communication with each other across the membrane, and the component is configured to fluidly connect the first luminal space to a dialysis supply reservoir and fluidly connect the second luminal space to a waste dialysate reservoir.

[0031] In some embodiments, the membrane is as described in PCT Application No. PCT/US2017/67141, filed December 18, 2017, incorporated herein by reference in its entirety. In some embodiments, the membrane may be constructed from any biologic, synthetic, or composite material suitable for thin film deposition and capable of maintaining mechanical viability and barrier integrity between compartments. This membrane may contain pores, slits, surface roughness, or other functional characteristics imparted during fabrication using techniques known to the art designed to improve function, biocompatibility, or other qualities of the membrane. The membrane may be manufactured from biologic, synthetic, or composite materials such as collagen, gelatin, other hydrogels, cellulose, or other materials that can be deposited in a thin film and subsequently crosslinked, dried, gelled, cured, or otherwise stabilized to form a cohesive and mechanically stable membrane. This membrane may undergo further treatment or manipulation to provide enhanced function or mechanics. This membrane may be of uniform or varying thicknesses in the range of 0.01 μπι to 100 μπι or greater.

[0032] In some embodiments, the first and second luminal spaces are embedded in a first and second scaffold, respectively. In some embodiments, the first and second scaffolds comprise a polymer or a hydrogel. In some embodiments, the scaffolds comprise hydrogels such as gelatin, PLA, chitosan, composites of hydrogels or other hydrogel materials and composites of various concentrations and compositions. In some embodiments, varying the hydrogel materials and composites of various concentrations and compositions enable tuning of mechanical and biological properties of the scaffold which can enhance and further specialize tissue constructs for desired biological applications. In some embodiments, the scaffold can comprise an addition of glycerin, sorbitol, propylene glycol, or other plasticizers into gelatin or gelatin composite hydrogels. The composition of the scaffold is not limited and may be any suitable scaffold material known in the art.

[0033] In some embodiments, the first luminal space comprises a first microchannel network in fluid communication with the first surface of the membrane. In some

embodiments, the second luminal space comprises a second microchannel network in fluid communication with the second surface of the membrane. In some embodiments, both the first and second luminal space comprise a microchannel network (e.g., a vascular network). In some embodiments, the microchannel network is manufactured by the methods disclosed in PCT Application No. PCT/US2017/67141, filed December 18, 2017, incorporated herein by reference in its entirety. Briefly, a sacrificial material is overlaid on the membrane, followed by scaffold material; then the sacrificial material is removed, leaving a luminal space (e.g., microchannel network, vascular channel network) bounded by the scaffold material and the membrane. In other embodiments, the luminal space is completely defined by membrane (e.g., the membrane surrounds the luminal space). [0034] In some embodiments, one or more luminal spaces comprise one or more channels (e.g., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,.12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, 100, 200, 500, 750, 1000, 2000, 10000 channels). In some embodiments, the at least one channel comprises a branching channel network having one or more branches with decreasing diameters (e.g., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,.12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, 100, 200, 500, 750, 1000, 2000, 10000 branches). Luminal spaces (e.g., microchannel diameters, vascular network channel diameters) can be any suitable diameter. In some embodiments, luminal space diameters can include, but not be limited to, about 10 cm, 5 cm, 2 cm, 1 cm, 500 mm, 250 mm, 100 mm, 50 mm, 10 mm, 5 mm, 1 mm, 500 μηι, 50 μηι, 10 μηι, 5 μηι, 3 μηι, 1 μηι, 0.5 μηι, 0.1 μηι, 0.05 μηι, 0.02 μηι, or 0.01 μιη.

[0035] In some embodiments, the component does not comprise a scaffold. Instead, structural supports hold the membrane in place between a luminal space in fluid

communication with a waste dialysate source and a luminal space in fluid communication with a dialysate (e.g., fresh dialysate, cell-enhanced dialysate) source. The structural support may be any suitable structural support material. In some embodiments, the structural support material is plastic.

[0036] In some embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by 5-100 μΜ or more. In some

embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by 5-10 μΜ. In some embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by about 0.1 μΜ to about 100 μΜ, of about 0.1 μΜ to about 100 μΜ, of about 0.5 μΜ to about 50 μΜ, of about 1.0 μΜ to about 40 μΜ, of about 5.0 μΜ to about 30 μΜ, or of about 10 μΜ to about 20 μΜ, or any range therebetween. In some embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by about 10 μΜ or less. In some embodiments, first and second luminal spaces are separated from each other on opposite surfaces of the membrane by about 8-4 μΜ. In some embodiments, the first and second luminal spaces are separated from each other on opposite surfaces of the membrane by about 5 μΜ or less.

[0037] In some embodiments, the membrane separating the luminal spaces has a thickness of about 0.1 μΜ to about 100 μΜ, of about 0.1 μΜ to about 100 μΜ, of about 0.5 μΜ to about 50 μΜ, of about 1.0 μΜ to about 40 μΜ, of about 5.0 μΜ to about 30 μΜ, or of about 10 μΜ to about 20 μΜ, or any range therebetween. In some embodiments, the membrane separating the luminal spaces has a thickness of about 10 μΜ or less. In some embodiments, the membrane separating the luminal spaces has a thickness of about 8-4 μΜ. In some embodiments, the membrane separating the luminal spaces has a thickness of about 5 μΜ or less.

[0038] In some embodiments, the component further comprises a housing configured to connect the component to a dialysate reservoir and a waste dialysate reservoir. In some embodiments, the housing is a sterile plastic housing with barbed connections for connecting to dialysate and waste dialysate channels. In some embodiments, the housing closely fits around the membrane and/or scaffold.

[0039] In some embodiments, the component further comprises one or more pumps for circulating the dialysate and waste dialysate through the component. Any pump suitable for sterile liquids may be used. In some embodiments, the pump is a peristaltic pump or a roller pump. In some embodiments, the component comprises a pump for circulating the dialysate and another pump for circulating the waste dialysate.

[0040] In some embodiments, the area of membrane across which the first and second luminal spaces are in fluid communication across the membrane is at least 30 cm , at least 60 cm², at least 90 cm², at least 100 cm², at least 150 cm², at least 200 cm², at least 250 cm², at least 300 cm², at least 450 cm², at least 600 cm², at least 800 cm², at least 1000 cm², or at least 1200 cm² or more. In some embodiments, at least 10%, 20%, 30%, 40%, 50%, 60%, 70%), 80%), 90%), 95%), 99%o, or more of the first and/or second luminal space is in fluid communication across the membrane with the other luminal space.

[0041] Prior to use, the component may be stored. In some embodiments, the membrane and/or scaffold is stored in dehydrated form. In some embodiments, the component is stored with the membrane and/or scaffold in hydrated form. For example, the component may be stored in a sterile fluid and/or at refrigeration temperatures.

[0042] In some embodiments, the component further comprises cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) on the first surface of the membrane, on the second surface of the membrane, or the first and second surfaces of the membrane. In some embodiments, the cells are at confluence on a membrane surface. In some embodiments, the component comprises at least 2xl0⁶ cells. In some embodiments, the component comprises at least lxlO⁷ cells. In some embodiments, the component comprises at

1 2 2 least 2x10 cells. In some embodiments, the cells are on at least 30 cm , at least 60 cm , at

2 2 2 2 2 least 90 cm , at least 100 cm , at least 150 cm , at least 200 cm , at least 250 cm , at least 300 cm², at least 450 cm², at least 600 cm², at least 800 cm², at least 1000 cm², or at least 1200 cm² or more of membrane surface. For example, cells can be on 15 cm² of each side of the membrane (i.e., the first and second side of the membrane) for a total of 30 cm² of surface area of the membrane. In some embodiments, the cells are only on the first membrane surface (i.e., the side facing the dialysate). In some embodiments, the cells are only on the second membrane surface (i.e., the side facing the waste dialysate). In some embodiments, the cells are on both membrane surfaces. In some embodiments, the cells are renal tubule epithelial cells. In some embodiments the cells are renal tubule epithelial cells and endothelial cells. For example, the renal tubule epithelial cells can be on one membrane surface and the endothelial cells can be on anther surface.

[0043] In some embodiments, the cells are allogenic to a patient using the component. In some embodiments, the cells are autologous to a patient using the component. In some embodiments, the cells are from a cell line. In some embodiments, the cells are autologous stem cell derived cells. In some embodiments, the autologous stem cells are derived from induced pluripotent stem cells.

[0044] Some embodiments comprise a peritoneal dialysis system comprising one or more dialysate regeneration or enhancement components as described herein. In some embodiments, the peritoneal dialysis system comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more dialysate regeneration or enhancement components as described herein. In some

embodiments having greater than one dialysate regeneration or enhancement component, the dialysate regeneration or enhancement components are connected in serial or are connected to one or more manifolds that control flow (e.g., equalize flow) of dialysate and/or waste dialysate to the components. In some embodiments, the peritoneal dialysis system is an automated peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is a continuous flow peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is continuous ambulatory peritoneal dialysis system.

[0045] Some aspects of the disclosure are related to a dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is embedded in a first scaffold comprising a polymer or hydrogel and the first luminal space comprises a first microchannel network in fluid communication with the first surface of the membrane, and the second luminal space is embedded in a second scaffold comprising a polymer or hydrogel and the second luminal space comprises a second microchannel network in fluid

communication with the second surface of the membrane, wherein the first and second luminal spaces are separated from each other on opposite sides of the membrane by a width of 5 to 10 μΜ, and wherein the component is configured to fluidly connect the first luminal space to a dialysis supply reservoir and fluidly connect the second luminal space to a waste dialysate reservoir. In some embodiments, the component further comprises cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) on the first surface and/or second surface of the membrane.

[0046] In some aspects, the component comprises a housing, an area of membrane across which the first and second luminal spaces are in fluid communication, an amount of cells, a surface area of one or both membrane surfaces covered by cells, and/or a type (e.g., allogenic) of cells as described herein. Some embodiments are related to a peritoneal dialysis system comprising the dialysate regeneration or enhancement component described herein. In some embodiments, the peritoneal dialysis system is an automated peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is a continuous flow peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is continuous ambulatory peritoneal dialysis system.

[0047] Some aspects of the disclosure are related to a peritoneal dialysis system comprising a dialysate supply reservoir, a waste dialysate reservoir, and one or more dialysate regeneration or enhancement components, wherein the dialysate regeneration or enhancement component comprises a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, and the first and second luminal spaces are in fluid communication with each other across the membrane; the first luminal space is fluidly connected to the dialysate supply reservoir, thereby enabling circulation of dialysate between the dialysate supply reservoir and the first luminal space; the second luminal space is fluidly connected to the waste dialysate reservoir, thereby enabling circulation of dialysate between the waste dialysate reservoir and the second luminal space; and at least a portion of the first and/or second luminal space in fluid communication with the membrane comprises cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells).

[0048] In some embodiments, the peritoneal dialysis system further comprises one or more pumps configured to circulate dialysate between the dialysate supply reservoir and the first luminal space and circulate dialysate between the waste dialysate reservoir and the second luminal space. Any pump suitable for sterile liquids may be used. In some embodiments, the pump is a peristaltic pump or a roller pump.

[0049] In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate of less than about 2000 ml/min, 1500 ml/min, 1400 ml/min, 1300 ml/min, 1200 ml/min, 1100 ml/min, 1000 ml/min, 900 ml/min, 800 ml/min, 700 ml/min, 600 ml/min, 500 ml/min, 400 ml/min, 300 ml/min, or 200 ml/min. In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate of about 1000-500 ml/min or 600-900 ml/min. In some embodiments, the dialysate and/or waste dialysate are pumped at a flow rate of 1.0-1.5 ml/min per 1 cm² surface area of the membrane. In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate resulting in a pressure of less than or equal to about 150 cmffiO, 140 cmffiO, 130 cmffiO, 120 cmffiO, 100 cmffiO, 90 cmffiO, 80 cmH20, 70 cmH20, or 60 cmH20, or any range therebetween. In some embodiments, the dialysate and waste dialysate are pumped in opposite directions across the membrane (i.e., countercurrent).

[0050] In some embodiments, the peritoneal dialysis system is configured to deliver dialysate to the peritoneal cavity of a patient from the dialysate supply reservoir and configured to remove waste dialysate from the patient's peritoneal cavity to a waste dialysate reservor. In some embodiments, the peritoneal dialysis system comprises one or more pumps and one or more catheters configured to deliver and remove dialysate from a patient's peritoneal cavity. In some embodiments, the dialysate regeneration or enhancement component is a component as described herein. In some embodiments, the peritoneal dialysis system is configured to enable removal or replacement of a dialysate regeneration or enhancement component during use (i.e., hot swappable). In embodiments of the peritoneal dialysis system having more than one dialysate regeneration or enhancement components is configured to enable removal or replacement of one or more dialysate regeneration or enhancement component during use.

[0051] In some embodiments, the peritoneal dialysis system is an automated peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is a continuous flow peritoneal dialysis system. In some embodiments, the peritoneal dialysis system is continuous ambulatory peritoneal dialysis system.

[0052] Some aspects of the disclosure are related to a method of producing cell- enhanced dialysate comprising: providing a source of dialysate, a source of waste dialysate, and a dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space and cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) on at least one surface of the membrane, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, and the first and second luminal spaces are in fluid communication with each other across the membrane; and pumping waste dialysate from the source of waste dialysate through the second luminal space and pumping dialysate from the source of dialysate through the first luminal space, wherein the cells transport compounds from the waste dialysate across the membrane into the dialysate, thereby producing cell- enhanced dialysate.

[0053] In some embodiments, the cells selectively transport one or more of water, glucose, electrolytes, amino acids, bicarbonate, sodium, vitamins, calcium, chloride, magnesium and other beneficial compounds. In some embodiments, the selectively transport water, glucose, electrolytes, amino acids, bicarbonate, sodium, vitamins, calcium, chloride, magnesium and other beneficial compounds.

[0054] In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate of less than about 2000 ml/min, 1500 ml/min, 1400 ml/min, 1300 ml/min, 1200 ml/min, 1100 ml/min, 1000 ml/min, 900 ml/min, 800 ml/min, 700 ml/min, 600 ml/min, 500 ml/min, 400 ml/min, 300 ml/min, or 200 ml/min. In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate of about 1000-500 ml/min or 600-900 ml/min. In some embodiments, the dialysate and/or waste dialysate are pumped at a flow rate of 1.0-1.5 ml/min per 1 cm² surface area of the membrane. In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate resulting in a pressure of less than or equal to about 150 cmffiO, 140 cmffiO, 130 cmffiO, 120 cmffiO, 100 cmffiO, 90 cmffiO, 80 cmH20, 70 cmH20, or 60 cmH20, or any range therebetween. In some embodiments, the dialysate and waste dialysate are pumped in opposite directions across the membrane (i.e., countercurrent).

[0055] In some aspects, the component comprises a housing, an area of membrane across which the first and second luminal spaces are in fluid communication, an amount of cells, a surface area of one or both membrane surfaces covered by cells, and/or a type (e.g., allogenic) of cells as described herein. In some embodiments, the dialysate regeneration or enhancement component is a dialysate regeneration or enhancement component as described herein.

[0056] Some aspects of the disclosure are directed to a method of performing peritoneal dialysis comprising: pumping dialysate along a first flow path out of a dialysate supply reservoir into a peritoneal cavity of a subject; pumping waste dialysate along a second flow path out of the peritoneal cavity into a waste dialysate reservoir; pumping waste dialysate along a third flow path out of the waste dialysate reservoir, through a dialysate regeneration or enhancement component comprising a membrane, and back into the waste dialysate reservoir; and pumping dialysate along a fourth flow path out of the dialysate supply reservoir, through the dialysate regeneration component comprising a membrane, and back into the dialysate supply reservoir; wherein the fourth flow path comprises a first luminal space in fluid communication with a first side of the membrane, wherein the third flow path comprises a second luminal space comprising cells (e.g., renal tubule epithelial cells or renal tubule epithelial cells and endothelial cells) that are in fluid communication with a second side of the membrane, and wherein the cells transport compounds from waste dialysate in the third flow path across the membrane into dialysate in the fourth flow path. In some embodiments, the cells selectively transport one or more of water, glucose, electrolytes, amino acids, bicarbonate, sodium, vitamins, calcium, chloride, magnesium and other beneficial compounds. In some embodiments, the cells selectively transport water, glucose, electrolytes, amino acids, bicarbonate, sodium, vitamins, calcium, chloride, magnesium and other beneficial compounds.

[0057] In some embodiments, the method of performing peritoneal dialysis further comprises adding, reducing or eliminating bioactive compounds in the waste dialysate. In some embodiments, the bioactive compounds modulate one or more functions (e.g., transport functions) of the cells. In some embodiments, the bioactive compounds are endocrine hormones. In some embodiments, the bioactive compounds modulate absorption of specific solutes (e.g., sodium, phosphate, water) or water. In some embodiments, the bioactive compounds are selected from antidiuretic hormone, vasopressin, angiotensin II and parathyroid hormone.

[0058] In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate of less than about 2000 ml/min, 1500 ml/min, 1400 ml/min, 1300 ml/min, 1200 ml/min, 1100 ml/min, 1000 ml/min, 900 ml/min, 800 ml/min, 700 ml/min, 600 ml/min, 500 ml/min, 400 ml/min, 300 ml/min, or 200 ml/min. In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate of about 1000-500 ml/min or 600-900 ml/min. In some embodiments, the dialysate and/or waste dialysate are pumped at a flow rate of 1.0-1.5 ml/min per 1 cm surface area of the membrane. In some embodiments, the dialysate and/or waste dialysate are pumped through the component at a flow rate resulting in a pressure of less than or equal to about 150 cmffiO, 140 cmffiO, 130 cmffiO, 120 cmffiO, 100 cmffiO, 90 cmffiO, 80 cmH20, 70 cmH20, or 60 cmH20, or any range therebetween. In some embodiments, the dialysate and waste dialysate are pumped in opposite directions across the membrane (i.e., countercurrent). [0059] In some embodiments, the peritoneal dialysis system comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more dialysate regeneration or enhancement components as described herein. In some embodiments having greater than one dialysate regeneration or enhancement component, the dialysate regeneration or enhancement components are connected in serial or are connected to one or more manifolds that control flow (e.g., equalize flow) of dialysate and/or waste dialysate to the components. In some aspects, the component comprises a housing, an area of membrane across which the first and second luminal spaces are in fluid communication, an amount of cells, a surface area of one or both membrane surfaces covered by cells, and/or a type (e.g., allogenic) of cells as described herein. In some embodiments, the dialysate regeneration or enhancement component is a component described herein.

***

[0060] One skilled in the art readily appreciates that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The details of the description and the examples herein are

representative of certain embodiments, are exemplary, and are not intended as limitations on the scope of the invention. Modifications therein and other uses will occur to those skilled in the art. These modifications are encompassed within the spirit of the invention. It will be readily apparent to a person skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention.

[0061] The articles "a" and "an" as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to include the plural referents. Claims or descriptions that include "or" between one or more members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The invention includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The invention also includes embodiments in which more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process. Furthermore, it is to be understood that the invention provides all variations, combinations, and permutations in which one or more limitations, elements, clauses, descriptive terms, etc., from one or more of the listed claims is introduced into another claim dependent on the same base claim (or, as relevant, any other claim) unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise. It is contemplated that all embodiments described herein are applicable to all different aspects of the invention where appropriate. It is also contemplated that any of the embodiments or aspects can be freely combined with one or more other such embodiments or aspects whenever appropriate. Where elements are presented as lists, e.g., in Markush group or similar format, it is to be understood that each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should be understood that, in general, where the invention, or aspects of the invention, is/are referred to as comprising particular elements, features, etc., certain embodiments of the invention or aspects of the invention consist, or consist essentially of, such elements, features, etc. For purposes of simplicity those embodiments have not in every case been specifically set forth in so many words herein. It should also be understood that any embodiment or aspect of the invention can be explicitly excluded from the claims, regardless of whether the specific exclusion is recited in the specification. For example, any one or more active agents, additives, ingredients, optional agents, types of organism, disorders, subjects, or combinations thereof, can be excluded.

[0062] Where the claims or description relate to a composition of matter, it is to be understood that methods of making or using the composition of matter according to any of the methods disclosed herein, and methods of using the composition of matter for any of the purposes disclosed herein are aspects of the invention, unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise. Where the claims or description relate to a method, e.g., it is to be understood that methods of making compositions useful for performing the method, and products produced according to the method, are aspects of the invention, unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise.

[0063] Where ranges are given herein, the invention includes embodiments in which the endpoints are included, embodiments in which both endpoints are excluded, and embodiments in which one endpoint is included and the other is excluded. It should be assumed that both endpoints are included unless indicated otherwise. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or subrange within the stated ranges in different embodiments of the invention, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. It is also understood that where a series of numerical values is stated herein, the invention includes embodiments that relate analogously to any intervening value or range defined by any two values in the series, and that the lowest value may be taken as a minimum and the greatest value may be taken as a maximum. Numerical values, as used herein, include values expressed as percentages. For any embodiment of the invention in which a numerical value is prefaced by "about" or "approximately", the invention includes an embodiment in which the exact value is recited. For any embodiment of the invention in which a numerical value is not prefaced by "about" or "approximately", the invention includes an embodiment in which the value is prefaced by "about" or "approximately".

[0064] As used herein "A and/or B", where A and B are different claim terms, generally means at least one of A, B, or both A and B. For example, one sequence which is complementary to and/or hybridizes to another sequence includes (i) one sequence which is complementary to the other sequence even though the one sequence may not necessarily hybridize to the other sequence under all conditions, (ii) one sequence which hybridizes to the other sequence even if the one sequence is not perfectly complementary to the other sequence, and (iii) sequences which are both complementary to and hybridize to the other sequence.

[0065] "Approximately" or "about" generally includes numbers that fall within a range of 1% or in some embodiments within a range of 5% of a number or in some embodiments within a range of 10% of a number in either direction (greater than or less than the number) unless otherwise stated or otherwise evident from the context (except where such number would impermissibly exceed 100% of a possible value). It should be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one act, the order of the acts of the method is not necessarily limited to the order in which the acts of the method are recited, but the invention includes embodiments in which the order is so limited. It should also be understood that unless otherwise indicated or evident from the context, any product or composition described herein may be considered "isolated".

[0066] As used herein the term "comprising" or "comprises" is used in reference to compositions, methods, and respective component(s) thereof, that are essential to the invention, yet open to the inclusion of unspecified elements, whether essential or not.

[0067] As used herein the term "consisting essentially of refers to those elements required for a given embodiment. The term permits the presence of additional elements that do not materially affect the basic and novel or functional characteristic(s) of that embodiment of the invention. [0068] The term "consisting of refers to compositions, methods, and respective components thereof as described herein, which are exclusive of any element not recited in that description of the embodiment.

EXAMPLES

[0069] Membrane Manufacture

[0070] In step 1, a biocompatible membrane material or a combination of such membrane materials is deposited on a substrate using techniques known to the art such as thin film deposition using physical or chemical methods. This membrane is then cured, dried, partially or fully crosslinked, or otherwise solidified and removed from the substrate to form a uniform membrane.

[0071] In step 2, a blueprint of one or more channel networks constructed of sacrificial materials is deposited onto the surfaces of the membrane, forming channel network(s) configured in a flow path for dialysate and waste dialysate. This can be accomplished using techniques know in the art including but not limited to extrusion, molding, milling, or additive printing. If necessary, a mechanical support material can be used, which may or may not also be a sacrificial material.

[0072] In step 3, scaffold material is deposited on the membrane over the sacrificial material.

[0073] In step 4, the sacrificial channel materials are removed, leaving multiple luminal spaces lined by a thin film membrane.

[0074] In step 5, the membrane and scaffold is encased in a plastic housing having ports for connection to a dialysate source and waste dialysate source.

[0075] Cell Enhanced Peritoneal Dialysis

[0076] The purpose of the disclosed device is to significantly reduce the total volume of dialysate necessary to no more than 2-3 liters, without compromising the high rate of cycling. This allows for a more practical treatment involving significantly less dialysate, making it less cumbersome, more cost effective, and thus suitable for wider use. By recycling dialysate the device drastically changes the cost effectiveness per liter. The result is that the number of exchanges performed no longer drives the total dialysate volume used during treatment. By effectively unlinking the total volume and total number of exchanges, the disclosed device can allow shorter dwell times, and potentially the practical implementation of continuous flow peritoneal dialysis (CFPD) which currently requires in excess of 200 liters of dialysate per day but is proven to be the most effective PD modality (2-7).

[0077] The CPD device takes the form of a firm hydrogel scaffold containing micro- channel networks separated into two distinct compartments by a membrane coated in allogenic renal tubule epithelial cells. These counter-current channels are fed by pumps and drained passively. By perfusing one side with waste dialysate and the other with fresh dialysate from the conventional APD reservoirs, the native transport function of the membrane cells is used to selectively reclaim water, glucose, electrolytes, amino acids, and other valuable molecules and fluid from waste dialysate. This allows for the recycling of saturated waste dialysate into regenerated dialysate that is supplied to the APD device, subsequently allowing for a drastic reduction in overall dialysate volume required for effective APD treatment and cycling. The renal tubule cells on the membrane can effectively be kept alive by the circulating waste dialysate, and have the potential to provide

immunological and endocrinological support as demonstrated by trials using bioartificial kidneys (BAKs)(12, 13) and bioartificial renal epithelial cell systems (BRECS)(11) in acute and chronic examples of renal failure. The device will provide an adjunct therapy to APD, and will allow increased cycling of dialysate which will improve patient outcomes and overall mortality compared to other PD methods (4-7). In addition this device is an enabling technology that will provide a platform for developing more compact and portable PD devices and eventually CFPD devices. The membrane technology has potential applications in other dialysis modalities as well.

[0078] Design Criteria:

[0079] CPD device design is centered around the "living" hydrogel membrane technology developed by IVIVA Medical. The 5μπι hydrogel membrane is embedded in a stiff hydrogel scaffold of identical composition containing countercurrent micro-channels for fresh dialysate and waste dialysate perfusion. These channels are both acellular (fresh dialysate side) and populated with renal proximal cells (waste dialysate side) to create a living membrane and channel network that mimics native proximal tubule function, allowing for recycling of waste dialysate into reusable dialysate. This scaffold is housed in a sterile plastic casing with ports allowing for streamlined integration with standard dialysis tubing and pumping equipment.

[0080] Membrane Size:

[0081] The amount of transport, metabolic, and endocrinologic function achieved is directly proportional to the surface area of membrane within the device. In order to achieve a clinically relevant level of function we estimate a tubule cell content of no less than 2x10 total cells will be necessary (11). Confluent cells occupy membrane surface area at a density of approximately 35,000 per cm , which necessitates a total device membrane surface area of roughly 600 cm with cells confluent on both sides. This is the total surface area necessary for clinical application, which can be achieved by combining multiple individual scaffold devices of lesser surface areas using a manifold to distribute flow evenly. This potential modularity allows for scaling of regeneration to meet variable demand and for "hot swapping" of scaffolds in the event of damage or loss of function.

[0082] Form Factor:

[0083] The scaffold containing the membrane and channels is square in shape, with entry and exit points for dialysate and waste channels at each of the corners. This hydrogel block is contained within a sterile, tight fitting plastic housing that has barbed ports facing inward for secure connection to fresh and waste dialysate channels. The outside portion of the device contains ports which interface with manifolds to allow for parallel integration of multiple devices. These manifolds subsequently interface with flow from the dialysis circuit and allow drainage back to the reservoirs.

[0084] Operating Parameters:

[0085] The individual dialysate regeneration device operates at a low flow rate per cm , with specific flow rates dependent on the membrane surface area, channel volume, and resistance. The critical physical constraint on device function is overall pressure which is a function of flow and resistance. In order to prevent membrane breakage pressures below 100 cmH20 should be maintained. Initial device testing suggests low pressure flow rates of 1.0- 1.5 ml/min per 1 cm are possible with counter- current channel architecture. This would allow for a maximum dialysate flow of 600-900 ml/min given the target of 600 cm total membrane area, providing significant additional capacity and buffer against excessive pressure. Not only does this capacity provide a substantial margin of safety for membrane rupture, it also allows for flexibility in scaling the cell content for a given dialysis session, and opens the possibility of applications in other types of high flow hemodialysis systems.

[0086] Device Safety:

[0087] Device safety is primarily contingent upon a lack of an adverse immunological response in the patient. Similar bioartificial devices with allogeneic cells have been used in series with standard hemodialysis in phase I and phase II clinical trials (BRECS, BAK)(11 - 13) for which the primary focus was evaluating safety. Outcomes showed no adverse allogeneic or allergic reactions. During animal and clinical trials safety of the IVIVA device will be monitored qualitatively by observation of symptoms such as bronchospasm.

Quantitative assessment of safety will be accomplished using white blood cell counts and testing for lactate dehydrogenase, free hemoglobin, and liver function which are all indicators of adverse interactions with the device. Because the device is extracorporeal and does not see blood flow it is possible to isolate the cell content within the device providing a high degree of safety (11, 13).

[0088] Device Lifespan and Storage:

[0089] There are multiple stages throughout the manufacturing process where storage can occur. Acellular membrane and scaffold components can be stored in a sterile dehydrated state for extended periods of time, and rehydrated as needed. Once rehydrated the membrane and scaffold components can be stored in sterile containers or packaging in a refrigerated environment for a month or more. Once incorporated into the device housing the cellular component is added and the complete device is maintained under sterile culture conditions for up to one month. During application, the device is maintained in a "living" state by circulation of waste dialysate which can be maintained during down time between APD treatments.

[0090] Cell Content and Membrane Function:

[0091] The cell content of the device will consist of allogeneic renal cells seeded onto the gelatin membrane and scaffold prior to clinical application. Cell populations will be grown to confluency on the membrane and maintained in that state prior to use, during which they will actively remodel the membrane to further resemble native renal tubule morphology including tight junctions and brush borders. The shelf life of this tubule cell population on our device has yet to be determined, however given sterile culture conditions, cell population viability and device patency could reasonably be expected to last in the range of weeks to months (11-15). The use of primary allogeneic cells in the device would require a consistent source of cells (i.e. discard kidneys unsuitable for transplant)(14) however given the extracorporeal nature of the device and the isolation of the cell content, the use of commercial banked lines of non-primary cells is possible. This will drastically reduce the cost of the cellular component as well as streamline device construction and supply chain management. The membrane function, including filtration, diffusion, and reabsorption of water and molecules will depend on several conditions which can be manipulated to alter function as desired. To actively control the overall rate of dialysate recycling the flow rate to the device can be modulated. More specific control is also possible. The cells lining the membrane exhibit tight control of the transport into and out of the waste dialysate as they do during normal renal function. By controlling levels of circulating endocrine hormones in the waste dialysate we can in theory alter the absorption of specific solutes to control the composition of the recycled dialysate as well as the rate at which dialysate is recycled. Antidiuretic hormone or vasopressin regulates aquaporins and water reclamation, angiotensin II upregulates sodium absorption, and active transport of phosphate is suppressed by parathyroid hormone which also can increase calcium absorption. Our device uses cells to provide function, which allows for modification of that function through the same mechanisms used to modify native renal function. One could also speculate that in future devices a cell population with genetically modified transport function could provide further means of control and modulation of transport.

[0092] Interaction with Current PD Therapies:

[0093] Implementation of the dialysate regeneration device requires minimal modification of conventional APD circuits, which use dialysate and drainage reservoirs as the circuit end points and do not reuse dialysate. To implement the dialysate regeneration device, we will connect the waste dialysate reservoir and the fresh dialysate reservoir to the device pumps which will continually perfuse the regeneration device throughout APD treatment. Drainage lines will connect back to the reservoirs. The single CPD "module" will contain the pumps and support apparatus for the membrane device(s), including any heating or oxygenation segments to condition dialysate prior to contacting the cells. Adding the regeneration device to APD will not require any modification of existing APD devices, simply the addition of extra access ports to the reservoirs moving forward. The living membrane will actively reclaim water, salts, glucose, amino acids, electrolytes and other desirable molecules from the circulating waste dialysate. These components will constitute the recycled dialysate which will be deposited into the fresh dialysate reservoir that feeds the conventional APD device. This recycling of waste dialysate will significantly decrease total reservoir volumes, the need to empty waste reservoirs or add fresh dialysate, and the overall dialysate volume required for each APD session. Recycled dialysate can be considered "enhanced" via the addition of bioactive molecules from the renal cells which have been shown to provide immunological and endocrinological support in similar applications (11- 13). It is important to note that in addition to reclamation functions, proximal cells excrete drugs into the waste or urine stream. This function will serve to prevent recycling of drugs from drained dialysate into fresh dialysate, maintaining controlled dosing of medications. Since dialysate is often a route for administration of medication, using the regeneration device in conjunction with medication applied through PD will require directly administering drugs in the APD input flow as opposed to the dialysate reservoir to prevent excretion before the drugs can reach the patient.

[0094] Expected Benefits:

[0095] The CPD system will provide significant improvements over traditional APD and other peritoneal dialysis modalities. The most important benefit of the device is that it allows for regeneration of saturated dialysate into reusable dialysate via the active transport mechanisms of the renal cells on the device membrane. The proximal tubule function reclaims all the components of dialysate in roughly equal portions. This transport has the potential to be modified through the addition of hormones into the waste dialysate to directly control the action of the cells in the regeneration device like the endocrine control of the kidney. The amount of clearance achieved using peritoneal dialysis is proportional to the average concentration gradient established and the duration of the treatment. CFPD produces a large concentration gradient and maintains it for the duration of treatment which is why it is the most effective modality (2-7), however maintaining that gradient requires impractical volumes of dialysate. APD reduces the volume of dialysate necessary by dwelling, which makes the treatment practical however this weakens the average concentration gradient and reduces overall clearance and thus treatment efficacy. By using continuous recycling of dialysate this CPD device will bridge the gap between APD and CFPD, enabling a reduced total volume of dialysate and simultaneously an increased average concentration gradient through the possibility of higher cycling rates. This will allow for a CPD device in such a compact form as to be considered wearable or suitable for mobile treatment. This technology has significant potential applications in other hemodialysis and peritoneal dialysis treatment modalities as well.

[0096] Table 1: Benefits of IVIVA's "Cell Enhanced" peritoneal dialysis compared to current automated peritoneal dialysis, continuous flow peritoneal dialysis.

Full reclamation of all Single-use Single-use

dialysate components: dialysate fluid dialysate fluid

H₂0, Glucose,

electrolytes

Control of transport, Static dialysate Static dialysate

dialysate composition composition composition

during treatment

Enhanced dialysate, via

cellular endocrinological No No

and immunological enhancement enhancement

action

[0097] References:

[0098] 1. Khanna R, Krediet RT, eds. Nolph and Gokal's Textbook of Peritoneal Dialysis. 3rd ed. New York: Springer Science+Business Media; 2009

[0099] 2. Diaz-Buxo JA. Clinical Use of Peritoneal Dialysis. In: Nissenson AR, Fine RN, eds. Clinical Dialysis. 4th ed. New York: McGraw-Hill Medical Publication; 2005 :421- 490

[0100] 3. Nourse, P., et al. (2016). "Continuous flow peritoneal dialys is (CFPD) improves ultrafiltration in children with acute kidney injury on conventional PD using a 4.25 % dextrose solution." Pediatr Nephrol 31(7): 1137 - 1143.

[0101] 4. Raj DS, Self M, Work J. Hybrid dialysis: Recirculation peritoneal dialysis revisited. Am J Kidne y Dis 2000; 36: 58-67

[0102] 5. Mineshima M, Suzuki S, Sato Y, Ishimori I, Ishida K, Kaneko I, Agishi T. Solute removal characteristics of continuous recirculating peritoneal dialysis in experimental and clinical studies. ASAIO J 2000; 46: 95 -98

[0103] 6. Diaz-Buxo JA, Cruz C, Gotch FA. Continuous-flow peritoneal dialysis. Preliminary results. Blood Purif 2000; 18: 361-365

[0104] 7. Jutta Passlick-Deetjen, Eduard Quellhorst; Continuous flow peritoneal dialysis (CFPD): a glimpse into the future. Nephrol Dial Transplant 2001; 16 (12): 2296-2299

[0105] 8. Fissell, W. H, et al. (2013). "Achieving more frequent and longer dialysis for the majority: wearable dialysis and implantable artificial kidney devices." Kidney Int 84(2): 256-264.

[0106] 9. Burkart, J. (2009). "The future of peritoneal dialysis in the Unit ed States: optimizing its use." Clin J Am Soc Nephrol 4 Suppl 1 : S125-131. [0107] 10. U.S. Renal Data System, USRDS 2013 Annual Data Report: Atlas of End- Stage Renal Disease in the United States, National Institutes of Health, National Institute of Diabetes and Diges tive and Kidney Diseases, Bethesda, MD, 2014.

[0108] 11. Westover, A. J., et al. (2017). "A bio-artificial renal epithelial cell system conveys survival advantage in a porcine model of septic shock." J Tissue Eng Regen Med 11(3): 649-657.

[0109] 12. Humes, H. D., et al. (2004). "Initial clinical results of the bioartificial kidney containing human cells in ICU patients with acute renal failure." Kidney Int 66(4): 1578-1588.

[0110] 13. Johnston, K. A., et al. (2016). "Development of a wearable bioartificial kidney using the Bioartificial Re nal

[0111] 14. Epithelial Cell System (BRECS)." J Tissue Eng Regen Med.

[0112] 15. Westover, A. J., et al. (2012). "Enhanced propagation of adult human renal epithelial progenitor cells to improve cell sourcing for tissue-engineered therapeutic devices for renal diseases." J Tissue Eng Regen Med 6(8): 589-597.

[0113] 16. Mollet, B. B., et al. (2015). "A bioartificial environment for kidney epithelial cells based on a supramolecular polymer basement membrane mimic and an organotypical culture system. " J Tissue Eng Regen Med.

Claims

CLAIMS What is claimed is:

1. A dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, the first and second luminal spaces are in fluid communication with each other across the membrane, and the component is configured to fluidly connect the first luminal space to a dialysate supply reservoir and fluidly connect the second luminal space to a waste dialysate reservoir.

2. The component of claim 1, wherein the first and second luminal spaces are embedded in a first and second scaffold, respectively.

3. The component of claim 2, wherein the first and second scaffolds comprise a polymer or a hydrogel.

4. The component of claims 1-3, wherein the first luminal space comprises a first

microchannel network in fluid communication with the first surface of the membrane.

5. The component of claims 1-4, wherein the second luminal space comprises a second microchannel network in fluid communication with the second surface of the membrane.

6. The component of claims 1-5, wherein the first and second luminal spaces are

separated from each other on opposite surfaces of the membrane by 5-100 μΜ.

7. The component of claims 1-5, wherein the first and second luminal spaces are

separated from each other on opposite surfaces of the membrane by 5-10 μΜ.

8. The component of claims 1-7, further comprising a housing.

9. The component of claims 1-8, wherein the area of membrane across which the first and second luminal spaces are in fluid communication is at least 60 cm².

10. The component of claims 1-8, wherein the area of membrane across which the first and second luminal spaces are in fluid communication is at least 100 cm².

11. The component of claims 1-8, wherein the area of membrane across which the first and second luminal spaces are in fluid communication is at least 200 cm².

12. The component of claims 1-8, wherein the area of membrane across which the first and second luminal spaces are in fluid communication is at least 600 cm².

13. The component of claims 1-8, wherein the area of membrane across which the first and second luminal spaces are in fluid communication is at least 1200 cm .

14. The component of claims 1-13, further comprising renal tubule epithelial cells on the second surface of the membrane.

15. The component of claims 1-14, further comprising renal tubule epithelial cells on the first surface of the membrane.

16. The component of claims 14-15, wherein the renal tubule epithelial cells are at

confluence on the membrane.

17. The component of claims 14-16, wherein the component comprises at least 2xl0⁶ renal tubule epithelial cells.

18. The component of claims 14-16, wherein the component comprises at least lxlO⁷ renal tubule epithelial cells.

19. The component of claims 14-16, wherein the component comprises at least 2x10 renal tubule epithelial cells.

20. The component of claims 14-19, wherein the renal tubule epithelial cells are on at least 60 cm² of the membrane surface.

21. The component of claims 14-19, wherein the renal tubule epithelial cells are on at least 100 cm of the membrane surface.

22. The component of claims 14-19, wherein the renal tubule epithelial cells are on at least 200 cm² of the membrane surface.

23. The component of claims 14-19, wherein the renal tubule epithelial cells are on at least 600 cm of the membrane surface.

24. The component of claims 14-19, wherein the renal tubule epithelial cells are on at least 1200 cm² of the membrane surface.

25. The component of claims 14-24, wherein the renal tubule epithelial cells are allogenic to a patient using the component.

26. The component of claims 14-24, wherein the renal tubule epithelial cells are

autologous to a patient using the component.

27. The component of claims 14-24, wherein the renal tubule epithelial cells are from a renal tubule epithelial cell line.

28. The component of claims 1-27, wherein the component further comprises endothelial cells on the first and/or second surface of the membrane.

29. A peritoneal dialysis system comprising one or more components of claims 1-28.

30. A dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space, wherein

a. the first luminal space is embedded in a first scaffold comprising a polymer or hydrogel and the first luminal space comprises a first microchannel network in fluid communication with the first surface of the membrane, and

b. the second luminal space is embedded in a second scaffold comprising a

polymer or hydrogel and the second luminal space comprises a second microchannel network in fluid communication with the second surface of the membrane,

wherein the first and second luminal spaces are separated from each other on opposite sides of the membrane by a width of 5 to 10 μΜ, and wherein the component is configured to fluidly connect the first luminal space to a dialysate supply reservoir and fluidly connect the second luminal space to a waste dialysate reservoir.

31. The component of claim 30, further comprising renal tubule epithelial cells on the first and/or second surface of the membrane.

32. The component of claims 30-31, further comprising endothelial cells on the first and/or second surface of the membrane.

33. A peritoneal dialysis system comprising one or more components of claims 1-28.

34. A peritoneal dialysis system comprising a dialysate supply reservoir, a waste dialysate reservoir, and one or more dialysate regeneration or enhancement components, wherein:

a. the dialysate regeneration or enhancement component comprises a membrane having a first and second surface separating a first and second luminal space, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, and the first and second luminal spaces are in fluid communication with each other across the membrane;

b. the first luminal space is fluidly connected to the dialysate supply reservoir, thereby enabling circulation of dialysate between the dialysate supply reservoir and the first luminal space;

c. the second luminal space is fluidly connected to the waste dialysate reservoir, thereby enabling circulation of dialysate between the waste dialysate reservoir and the second luminal space; and d. at least a portion of the first and/or second luminal space in fluid

communication with the membrane comprises renal tubule epithelial cells.

35. The peritoneal dialysis system of claim 34, further comprising one or more pumps configured to circulate dialysate between the dialysate supply reservoir and the first luminal space and circulate dialysate between the waste dialysate reservoir and the second luminal space.

36. The peritoneal dialysis system of claims 34-35, configured to deliver dialysate to the peritoneal cavity of a patient from the dialysate supply reservoir and configured to remove waste dialysate from the patient's peritoneal cavity.

37. The peritoneal dialysis system of claims 34-36, further comprising endothelial cells on the first and/or second surface of the membrane.

38. The peritoneal dialysis system of claims 34-37, wherein the dialysate regeneration or enhancement component is the dialysate regeneration or enhancement component of claims 1-28.

39. A method of producing cell-enhanced dialysate comprising:

a. providing a source of dialysate, a source of waste dialysate, and a dialysate regeneration or enhancement component comprising a membrane having a first and second surface separating a first and second luminal space and renal tubule epithelial cells on at least the first and/or second surface of the membrane, wherein the first luminal space is in fluid communication with the first surface of the membrane, the second luminal space is in fluid communication with the second surface of the membrane, and the first and second luminal spaces are in fluid communication with each other across the membrane; and

b. pumping waste dialysate from the source of waste dialysate through the

second luminal space and pumping dialysate from the source of dialysate through the first luminal space,

wherein the renal tubule epithelial cells on a membrane surface transport compounds from the waste dialysate across the membrane into the dialysate, thereby producing cell-enhanced dialysate.

40. The method of claim 39, further comprising endothelial cells on the first and/or second surface of the membrane.

41. The method of claims 39-40, wherein the dialysate regeneration or enhancement component is the dialysate regeneration or enhancement component of claims 1-28.

42. A method of performing peritoneal dialysis comprising:

a. pumping dialysate along a first flow path out of a dialysate supply reservoir into a peritoneal cavity of a subject;

b. pumping waste dialysate along a second flow path out of the peritoneal cavity into a waste dialysate reservoir;

c. pumping waste dialysate along a third flow path out of the waste dialysate reservoir, through a dialysate regeneration or enhancement component comprising a membrane, and back into the waste dialysate reservoir; and d. pumping dialysate along a fourth flow path out of the dialysate supply

reservoir, through the dialysate regeneration component comprising a membrane, and back into the dialysate supply reservoir;

wherein the fourth flow path comprises a first luminal space in fluid communication with a first side of the membrane, wherein the third flow path comprises a second luminal space comprising renal tubule epithelial cells that are in fluid communication with a second side of the membrane and/or wherein the fourth flow path comprises a first luminal space comprising renal tubule epithelial cells that are in fluid

communication with a first side of the membrane, and wherein the renal tubule epithelial cells transport compounds from waste dialysate in the third flow path across the membrane into dialysate in the fourth flow path.

43. The method of claim 42, wherein the third and/or fourth flow path further comprises endothelial cells.

44. The method of claims 42-43, wherein the dialysate regeneration or enhancement component is the dialysate regeneration or enhancement component of claims 1-28.