US-12616785-B2 - Sorbent regeneration cartridge for dialysis

Abstract

Sorbent regeneration systems for use in dialysis machines are described. Sorbent regeneration cartridges may include a layer of urease, a layer of acid zirconium phosphate, and a layer of sodium zirconium phosphate. An apparatus for conducting dialysis may include a sorbent cartridge, and a dialyzer in fluid communication with the sorbent cartridge, wherein spent dialysate passes from the dialyzer to and through the sorbent cartridge, and wherein the sorbent cartridge comprises a layer of urease, a layer of acid zirconium phosphate, and a layer of sodium zirconium phosphate. The urease may be immobilized to or associated with a carrier.

Inventors

• Brandon Borillo
• Tzu Tung Chen

Assignees

• DIALITY INC.

Dates

Publication Date

20260505

Application Date

20220526

Claims (14)

1. 1 . A sorbent cartridge comprising a layer of urease and iron hydroxide, a layer of acid zirconium phosphate, and a layer of zirconium phosphate, wherein the layer of acid zirconium phosphate is between the layer of urease and iron hydroxide and the layer of zirconium phosphate.
2. 2 . The cartridge of claim 1 , wherein the cartridge is configured such that spent dialysate contacts the layer of urease and iron hydroxide before the spent dialysate contacts either the layer of acid zirconium phosphate or the layer of zirconium phosphate.
3. 3 . The cartridge of claim 1 , wherein the cartridge is configured such that spent dialysate contacts the layer of acid zirconium phosphate before the layer of zirconium phosphate.
4. 4 . The cartridge of claim 1 , further comprising a layer of activated carbon.
5. 5 . The cartridge of claim 4 , wherein the cartridge is configured with a layer of activated carbon as the final layer.
6. 6 . The cartridge of claim 4 , wherein the cartridge is configured such that spent dialysate contacts the layer of activated carbon after the spent dialysate contacts the layer of urease and iron hydroxide.
7. 7 . The cartridge of claim 1 , further comprising a layer of zirconium oxide.
8. 8 . The cartridge of claim 7 , wherein zirconium oxide in the layer of zirconium oxide comprises zirconium oxide, zirconium hydroxide, zirconium oxide hydroxide, zirconium hydrous oxide, hydrous zirconium oxide, zirconium oxide with hydration, zirconium oxide without hydration, or combinations thereof.
9. 9 . The cartridge of claim 7 , wherein the cartridge is configured such that spent dialysate contacts the layer of zirconium oxide after the spent dialysate contacts the layer of acid zirconium phosphate.
10. 10 . The cartridge of claim 7 , wherein the cartridge is configured such that spent dialysate contacts the layer of zirconium oxide after the spent dialysate contacts the layer of zirconium phosphate.
11. 11 . The cartridge of claim 1 , wherein the layer of zirconium phosphate comprises sodium zirconium phosphate.
12. 12 . The cartridge of claim 1 , wherein urease in the layer of urease and iron hydroxide is immobilized.
13. 13 . The cartridge of claim 12 , wherein in the layer of urease and iron hydroxide, the immobilized urease is covalently bound to silica.
14. 14 . The cartridge of claim 1 , further comprising an additional layer of zirconium phosphate.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to, and the benefit of, U.S. Provisional Application No. 63/194,843, filed May 28, 2021, which is hereby expressly incorporated by reference in its entirety for all purposes. BACKGROUND OF THE INVENTION The present invention relates to cartridges that are useful in dialysis. In particular, the present invention relates in general to the regeneration or purification of used dialysate fluids. The present invention further relates to methods of conducting dialysis using certain cartridges and also relates to methods of making the cartridges. More than 1 in 7 adults in the U.S. (approximately 15 of U.S. adults) are estimated to have chronic kidney (or renal) disease. In people who suffer from chronic kidney disease, their kidneys no longer clean their blood as well as healthy kidneys. Thus, toxic waste and extra fluid accumulates in the body. Dialysis is a treatment that removes the waste products and excess fluid that accumulate in the blood as a result of kidney failure. Chronic renal failure is when the renal function has deteriorated to about 25% of normal. This amount of deterioration causes significant changes in the blood chemistry and is about the time that people feel poorly enough that they seek medical care. If medical treatment is sought at that time, progression can be slowed. Late-stage chronic renal failure is when kidney function has decreased to 15%. End stage renal failure is when kidney function is at 5% of normal. Death will most likely result without treatment at this point. Although there is no current cure for renal disease, there are several forms of treatment. One treatment is transplantation, which is where a human kidney is surgically placed in the body and connected to the bladder. After transplantation, daily medication is needed to keep the body from rejecting the transplanted kidney. Another treatment is peritoneal dialysis (PD). With this treatment, a mild saltwater solution containing dextrose and electrolytes called dialysate is put into the peritoneal cavity. Because there is a rich blood supply to this abdominal cavity, urea and other toxins from the blood and fluid are moved into the dialysate, thereby cleaning the blood. The dialysate is then drained from the peritoneum. Later “fresh” dialysate is again put into the peritoneum. Another form of treatment is hemodialysis. This is a method of blood purification in which blood is continually removed from the body and passed through a dialyzer (artificial kidney) where metabolic waste and excess water are removed and pH and acid/base balance are normalized. The blood is simultaneously returned to the body. The dialyzer is a small disposable device consisting of a semi-permeable membrane. The membrane allows the wastes, electrolytes, and water to cross but restricts the passage of large molecular weight proteins and blood cells. Blood is pumped across one side of the membrane as dialysate is pumped in the opposite direction across the other side of the membrane. The dialysate is highly purified water with salts and electrolytes added. The machine is a control unit that acts to pump and control pressures, temperatures, and electrolyte concentrations of the blood and the dialysate. The average length of one hemodialysis treatment is about 3.5 hours. There are several types of hemodialysis—including single pass systems and sorbent systems. Single pass hemodialysis is the most common treatment for renal disease. These instruments are called single pass because the dialysate (cleaning solution) passes by the blood in the dialyzer one time and then is disposed. Single pass dialysis machines generally require: (1) a water source capable of delivering at least 1000-1500 ml/min (assuming a 50% rejection rate by the reverse osmosis(R.O.) system); (2) a water purification system sufficient of providing a continuous flow of 500-800 ml/min of purified water, (3) an electrical circuit of at least 15 amps in order to pump and heal 500-800 ml of water/min, and (4) a floor drain or any other receptacle capable of accommodating at least 500 ml of used dialysate/minute as well as the rejected water from the R.O. system. Sorbent dialysis systems do not require a continuous water source, a separate water purification machine, or a floor drain because the system continuously regenerates a small volume of dialysate and incorporates a water treatment system within the machine. Therefore, sorbent systems are portable. The sorbent system can use 5-7 liters of sterile water, normal saline, half-normal saline, or dialysate from which dialysate is made or regenerated for an entire treatment. The sorbent system uses a sorbent cartridge, which removes uremic toxins without removing a majority of the salt allowing an efficient regeneration of used dialysate into fresh dialysate. The infusate system acts with the sorbent system to properly balance the electrolyte composition of the regenerat