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

Abstract

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.

Dialysate regeneration via urea photodecomposition with TiO2 nanowires at therapeutic rates

“…Sorbents have long been explored as an alternative route of urea removal 16–18 . To remove 15 g/day urea (250 mmol) with general activated carbon (AC) (0.2 mmol/g) 19 about 1.3 kg of AC is needed, while promising new polymers (0.6 mmol/g) 20 can reduce this adsorbent amount to 0.4 kg at physiological conditions. However, due to competition to binding sites from other species in the complex spent dialysate solutions, the effective binding capacity of most sorbents drops to <1 mg/g 21 .…”

Adsorption Dynamics of Uremic Toxins to Novel Modified Magnetic Nanoparticles

“…[ 5 ] For example, polymeric chemisorbents, with ninhydrin groups, have been studied for urea adsorption. [ 6 ] Magnetic nanoparticles (MNPs) have inherently advantageous properties that make them amenable for toxin adsorption. They are cost‐efficient, easy to regenerate, biodegradable, easy to spatially manipulate, afford facile surface modifications, have a high surface area (for capturing toxins), and exhibit excellent biocompatibility.…”