Researchers create functioning biological kidney tubule

Researchers at Utrecht University, Radboudumc and the University of Twente succeeded in creating a functioning biological ‘kidney tubule’. The tubule was made from living kidney tissue grafted to a dialysis membrane. This allows to excrete waste products from the blood that normal dialysis cannot remove. “We hope that this combination will eventually be able to replace the current dialysis technique”, according to Utrecht University Prof. Roos Masereew. The results of their research have recently been published in Scientific Reports on 16 November.

Current dialysis techniques can only remove small amounts of waste products from the blood, and cannot handle the waste products bound to proteins present in blood. The accumulation of wastes results in disease progression and an intoxication of the patients. “If we can develop our system into a clinical application, then hopefully the patient won’t have to go through the dialysis treatment as often, and there might also be a reduced risk of mortality”, explains Roos Masereeuw, Professor of Experimental Pharmacology at Utrecht University. The research project is a collaborative effort by Prof. Masereeuw, who came to Utrecht University this summer from Radboudumc, and Prof. Dimitrios Stamatialis from the University of Twente and Professors Joost Hoenderop and Bert van den Heuvel from Radboudumc.

6,500 DIALYSIS PATIENTS

Around 6,500 kidney patients in the Netherlands must undergo dialysis treatment for three or four times per week. The current dialysis techniques take over only a small part of the normal kidney function. Therefore, the health and quality of life is significantly compromised in patients suffering from kidney failure. Kidney transplants are often the best solution, but patients have to wait up to five years for a donor kidney. Each year, around 200 patients die because they did not receive a kidney transplant in time, so scientists around the world are studying alternative ways to improve the current dialysis techniques.

KIDNEY CELLS

The researchers from Utrecht, Nijmegen and Twente use human kidney cells, which are specialised in removing waste products from the blood. Unfortunately, growing kidney tissue on a dialysis membrane is an extremely complex process. Two years ago, the researchers succeeded in growing a single layer of kidney cells on a dialysis membrane. But it took two more years to make the step towards a functioning, three-dimensional kidney tubule consisting of a hollow fiber coated with a single layer of cells.

THE FUTURE

In order to actually apply the technique to treat kidney patients, the researchers must accurately identify the requirements that a biological kidney tubule must meet, so the study will focus on better understanding how the kidney cells excrete the waste products. “We are still a long way from a clinical application, but our results take us one step closer”, according to Prof. Masereeuw.

This study was funded in part by the Nierstichting, the Netherlands Institute for Regenerative Medicine (NIRM) and the European Marie Curie ITN project ‘Bioart‘.