Nanocellulose/activated carbon composite aerogel beads with high adsorption capacity for toxins in blood

Activated carbon is extensively utilized in blood purification applications. However, its performance has been significantly limited by their poor blood compatibility. In this work, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCN) and activated carbon (AC) were used to form composite beads by the drop curing method to improve hemocompatibility. The TOCN/AC composite beads had porous surface and exhibited extraordinary adsorption properties. The beads had a high adsorption capacity for creatinine with the optimal adsorption capacity of 83.33 mg g^-1. And the equilibrium adsorption of bilirubin, uric acid and Cu²⁺ by TOCN/AC beads was as high as 159.80 mg g^-1, 114.61 mg g^-1 and 154.0 mg g^-1, respectively, with a mass ratio of TOCN to AC of 1:4. It is also observed that the adsorption behavior of TOCN/AC beads on creatinine was consistent with the second-order kinetics and Langmuir isothermal model. The hemolysis rate of TOCN/AC was 1.21 %, indicating that TOCN/AC beads had good blood compatibility. The clearance of creatinine toxin in blood by TOCN/AC beads was as high as 87 % within 90 min. Overall, our produced composite beads had great potential for application in the field of blood purification.