Dialysis devices using nanoelectrokinetic technology can be used as portable artificial kidneys

The research team has developed a compact peritoneal dialysis device that can be used as a portable artificial kidney. The study was published in the Journal Journal of Nanobiotechnology on March 29th.

The number of dialysis patients due to renal failure continues to increase due to industrial development and changes in dietary habits. Hemodialysis methods commonly used to replace renal function currently have limitations that significantly limit the daily life of patients.

Not only is the device big, but patients need to spend 4-6 hours a day in the hospital, 2-3 times a week. Since the early 2000s, researchers from the US, European and Japanese have led the development of practical devices that individuals can carry and dialyze, but the lack of technology for creating miniaturized dialysis devices has made commercialization elusive.

Peritoneal dialysis provides an alternative to hemodialysis. In this method, dialysate is introduced into the peritoneal cavity where waste is removed through molecular exchange. This method allows patients to perform dialysis at home or elsewhere, thereby maintaining a more normal lifestyle.

The collaborative research team has demonstrated that a wearable peritoneal dialysis device can be realized by continuously purifying spent dialysate from the outside and reperfusion into the peritoneal cavity. The team proposed a novel purification mechanism using ion concentration polarization (ICP). This utilizes Coulomb forces to quickly separate ions and particles, effectively removing waste from the body.

ICP is a nanoelectrodynamic phenomenon in which a steep concentration gradient occurs near nanoporous membranes due to selective ion permeability. In this case, purified solutions collected from low concentration regions near the nanoporous membrane can be used for dialysis.

When an electric field is applied to the nanoporous membrane, the Coulomb force accelerates the ion separation and expands the purification zone. However, traditional electrodialysis methods have limited the complete purification of dialysate, as one of the main wastes in the body is urea neutral and not affected by Coulomb force.

To overcome this, the researchers further activated the selective ion permeability of nanoporous membranes, allowing for the electrochemical decomposition and removal of not only charged waste such as creatinine, but also neutral molecules such as urea. This principle was tested experimentally using microfluidic devices that control fluid flow through microchannels to induce chemical reactions.

The researchers’ final challenge was to increase the flow rate of dialysis fluid. To be viable as a wearable dialysis device, the device was required to achieve fluid handling capacity of ml per minute. However, traditional microfluidic devices have two-dimensional structures that limit the capacity of microliters per minute, making it difficult to expand sufficient flow.

To address this, the team designed micromesh structures that only form a nanoscale electrohydraulic environment near the nanoporous membrane, significantly increasing fluid throughput. As a result, they have successfully developed a 3D dialysis machine. The device achieved fluid processing speeds of up to 1 ml per minute. When applied to a rat model of renal failure, the device showed an average waste removal rate of approximately 30% per dialysis cycle.

If this peritoneal dialysis device is commercialized as a portable system, it is expected to significantly improve the quality of life of patients with renal failure. Additionally, it can reduce healthcare costs, reduce medical waste, increase accessibility of healthcare, and benefit patients in particular in low-income and developing countries.

The team was led by Professor Song Jae Kim of the Faculty of Electrical and Computer Engineering in collaboration with Seoul National University Hospital, Seoul National University School of Medicine, and Halim University.

Professor John Chang Lee of Seoul National University School of Medicine said, “For this peritoneal dialysis device to be applied to humans, it must be commercialized, safety assessment, clinical trials and regulatory approval of medical devices.

Professor Sung Song of Hallym University said, “This achievement marks the first successful application of nanotechnology in artificial organs. It is rewarding to know that this study can provide a better quality of life for patients with end-stage renal disease who suffer from low satisfaction with dialysis.”

Professor Yong Yong Yong Soo Kroa of Seoul National University Hospital said, “While there are various treatments for chronic kidney disease, patients struggle to maintain normal daily life. If the research results are commercialized, patients with chronic kidney disease can not only be more stable and more stable, but also plan a more active lifestyle.”

Professor Song Jae Kim of the Faculty of Electrical and Computer Engineering at Seoul National University said, “This research only goes beyond the development of advanced compact dialysis devices. It holds broad social implications, including improving patient quality of life, increasing medical costs, reducing medical costs, and advances in the medical device industry.

“While there were clear limitations to rat model testing, integrating ion-concentration-based waste removal and liquid expansion technology into artificial kidneys can help patients with end-stage renal disease gain mobility and significantly improve their standard of living.”