Facile Fabrication of Nanocellulose Beads with Tunable Carboxyl Content for Blood Purification

Most adsorbent materials typically face difficulties such as poor blood compatibility, weak mechanical strength, and high cost. In this study, oxidized 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was used to obtain cellulose nanofiber (TOCN), and cellulose beads were prepared using a drop curing method. The structure, adsorption properties, and blood compatibility of the prepared beads were thoroughly investigated. The TOCN beads exhibit a uniform, nanometer-scale, three-dimensional porous structure. With increasing carboxyl content, after adsorption of TOCN beads, the bilirubin concentration in rabbit plasma decreased from 0.03 to 0.0089 mg mL^-1 within 90 min, which is significantly lower than the average bilirubin concentration in humans (about 0.01 mg mL^-1), and the bilirubin concentration decreased by about 70%. The results illustrated the excellent blood compatibility, self-anticoagulant ability, and superior toxin removal capabilities of the TOCN beads, highlighting their potential as an ideal blood purification adsorbent.