A Ninhydrin-Type Urea Sorbent for the Development of a Wearable Artificial Kidney

Macromol Biosci. 2020 Mar;20(3):e1900396. doi: 10.1002/mabi.201900396. Epub 2020 Feb 17.


The aim of this study is to develop polymeric chemisorbents with a high density of ninhydrin groups, able to covalently bind urea under physiological conditions and thus potentially suitable for use in a wearable artificial kidney. Macroporous beads are prepared by suspension polymerization of 5-vinyl-1-indanone (vinylindanone) using a 90:10 (v/v) mixture of toluene and nitrobenzene as a porogen. The indanone groups are subsequently oxidized in a one-step procedure into ninhydrin groups. Their urea absorption kinetics are evaluated under both static and dynamic conditions at 37 °C in simulated dialysate (urea in phosphate buffered saline). Under static conditions and at a 1:1 molar ratio of ninhydrin: urea the sorbent beads remove ≈0.6-0.7 mmol g-1 and under dynamic conditions and at a 2:1 molar excess of ninhydrin ≈0.6 mmol urea g-1 sorbent in 8 h at 37 °C, which is a step toward a wearable artificial kidney.

Keywords: chemisorption; dialysis; ninhydrin; sorbent; urea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Humans
  • Kidneys, Artificial*
  • Ninhydrin / chemistry*
  • Urea / chemistry*
  • Wearable Electronic Devices*


  • Urea
  • Ninhydrin