Bottom-up Development of Urea Sorbents for Dialysate Regeneration

Urea removal from dialysate is crucial in the development of a miniature dialysis device. Materials that can bind urea via the formation of covalently bonds are promising for this application, however these materials lack fast urea removal kinetics. The aim of the project was to develop urea sorbents with fast urea removal kinetics and thus are able to remove the daily urea production of end-stage kidney disease patients (~400 mmol) with a few hundred grams of material. Three highly reactive molecules towards urea were indentified: triformylmethane, ninhydrin and phenylglyoxaldehyde. Subsequently, new materials with molecular structures such as ninhydrin and phenylglyoxaldehyde were synthesized and the urea removal kinetics were studied under static and dynamic conditions. It was found that approximately 600-700 grams of these materials are able to remove the daily urea production of ~400 mmol from dialysate, which is a step towards the realization of a miniature dialysis device.