A research team has developed a compact peritoneal dialysis device that can be utilized as a portable artificial kidney. This research was published on March 29 in the journal Journal of Nanobiotechnology.

Introduction

The number of patients on dialysis due to kidney failure continues to increase due to industrial development and changing dietary habits. Currently, the commonly used hemodialysis method to replace kidney function has limitations that significantly restrict patients' daily lives. Not only are the devices large, but they also require patients to spend four to six hours a day, two to three times a week in a hospital setting. Since the early 2000s, researchers in the U.S., Europe, and Japan have been leading the development of practical devices that individuals can carry around and dialyze with. However, the lack of technology to make miniaturized dialyzers has made commercialization elusive.

Peritoneal Dialysis as an Alternative

Peritoneal dialysis offers an alternative to hemodialysis. In this method, dialysis fluid is introduced into the peritoneal cavity, allowing for the removal of waste products through molecular exchange. This method offers patients the flexibility to perform dialysis at home or in other locations, thus enabling a more normal lifestyle.

Mechanism of the New Device

The joint research team successfully demonstrated that a wearable peritoneal dialysis device could function by continuously purifying used dialysis fluid externally and reinfusing it into the peritoneal cavity. The researchers proposed a novel purification mechanism using ion concentration polarization (ICP), which utilizes Coulomb force to rapidly separate ions and particles, efficiently removing waste products from the body.

How Ion Concentration Polarization Works

ICP is a nanoelectrokinetic phenomenon where a steep concentration gradient occurs near a nanoporous membrane due to its selective ion permeability. In this scenario, the purified solution collected from the low-concentration region near a nanoporous membrane is utilized for dialysis.

Conventional Method Proposed ICP Method
Relies on external hemodialysis at hospitals Portable, wearable device for dialysis
Cannot effectively remove neutral waste products like urea Enhanced mechanism for decomposing and removing neutral molecules

Challenges Overcome by the Research Team

The final challenge for the research team was increasing the dialysis fluid flow rate. To be viable as a wearable dialysis device, the device needed to achieve a fluid processing capacity of milliliters per minute. However, conventional microfluidic devices have a two-dimensional structure, limiting their capacity to microliters per minute.

To tackle this issue, the team designed a micro-mesh structure that creates a nanoscale electrohydrodynamic environment near the nanoporous membrane, significantly increasing fluid throughput. As a result, they successfully developed a three-dimensional dialysis device, achieving a fluid processing rate of up to one milliliter per minute. When tested on a rat model of kidney failure, the device showed an average waste removal rate of approximately 30% per dialysis cycle.

Potential Benefits and Future Directions

If this peritoneal dialysis device is commercialized as a portable system, it is expected to significantly improve the quality of life for patients with chronic kidney disease. Additional anticipated benefits include:

  • Reducing medical waste
  • Enhancing healthcare accessibility, particularly for low-income and developing country patients

Professor Sung Jae Kim of the Department of Electrical and Computer Engineering stated, "This research goes beyond merely developing an advanced compact dialysis device. It holds broad societal implications, including improving patients' quality of life and expanding healthcare accessibility."

Conclusion

This research marks a significant step forward in the use of nanoelectrokinetic technology for artificial organ development. It presents a promising avenue for improved dialysis methods that could transform treatment for patients with end-stage renal disease.

References

More information: Wonseok Kim et al, Scalable ion concentration polarization dialyzer for peritoneal dialysate regeneration, Journal of Nanobiotechnology (2025).

Source: Phys.org