# Scalable ion concentration polarization dialyzer for peritoneal dialysate regeneration

## TL;DR

A scalable dialyzer using ion concentration polarization was developed to purify dialysate for wearable artificial kidneys, showing promising toxin removal in animal models.

## Contribution

A 3-D scalable ICP dialyzer was developed with a 10,000-fold throughput increase and demonstrated in vivo toxin removal in a rat model.

## Key findings

- The ICP dialyzer achieved ~99% urea clearance and ~30% creatinine clearance in vitro.
- The 3-D dialyzer reached ~30% toxin clearance at 1 mL/min throughput.
- In vivo testing showed ~30% toxin removal per dialysis cycle in a rat model.

## Abstract

A wearable artificial kidney (WAK) stands poised to offer dialysis treatment with maximal temporal and spatial flexibility for end-stage renal disease (ESRD) patients, while portability has not yet been achieved due to difficulties in portable purification. The ion concentration polarization (ICP), one of the nanoelectrokinetic phenomenon, has garnered substantial attention in the realm of portable purification applications, owing to its remarkable capacity for charge separation. In this work, scalable ICP dialyzer with 10,000-fold increase in throughput, was applied for peritoneal dialysate regeneration. First, the mechanism underpinning dialysate purification was corroborated based on micro-nanofluidics. Simultaneously, the electrochemical reactions utilized the complete decomposition of uncharged toxin (urea), achieving approximately 99% clearance, while the ICP phenomenon promoted the removal of positively charged toxin (creatinine), achieving approximately 30% clearance. Second, 3-D scalable ICP dialyzer was developed with a creation of micro-nanofluidic environment inside. Throughput scalability was demonstrated up to 1 mL/min with average approximately 30% toxins clearance. Ultimately, the 3-D ICP dialyzer was applied to assist peritoneal dialysis (PD) using a bilateral nephrectomy rat model. We demonstrated that regenerated dialysate successfully reduced in vivo toxicity, with average toxins removal ratio of approximately 30% per cycle. We believe that the integration of this scalable ICP dialyzer into the WAK holds tremendous potential for substantially enhancing the quality of life for individuals with ESRD.

The online version contains supplementary material available at 10.1186/s12951-025-03294-1.