Efficient selective adsorption of cytokine IL-6 and other middle-macromolecular toxins in the serum of uremia patients with specially designed porous hollow carbon spheres

• Porous hollow carbon spheres (HCSs) with adjustable size and pore width distribution were synthesized. • The clearance rate of HCSs to interleukin 6 (IL-6) in PBS buffer solution was up to 99.8%. • HCSs had a high adsorption rate and removal efficiency for PTH, β 2 -MG, IL-6 and TNF-α in the serum of uremic patients. • The selective adsorption of middle-macromolecular toxins or cytokines was achieved by regulating the pore structure of HCSs. Abnormally elevated middle-macromolecular toxins such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF- α) in human blood are fatal precipitating factors for patients suffered from immune-related diseases, especially for uremia and COVID-19 critical patients, while the effective clearance of them has always been problematic in clinic. In this work, porous hollow carbon spheres (HCSs) with different size and pore structure has been successfully prepared. The removal efficiency for IL-6 in PBS solution is about 99.8%, even in the serum of uremic patients, HCSs could remove 94.75% and 98.33% of parathyroid hormone (PTH) and β 2 -microglobulin (β 2 -MG) efficiently within 5-10 min, and particularly, the adsorption of IL-6 and TNF- α is 17.6 and 11.4 times higher over that of the existing commercial hemoperfusion adsorbents. The adsorption balance can be achieved in 60 min, which would greatly shorten the current clinical treatment duration. Moreover, HCSs with different pore structure exhibit distinct adsorption selectivity for IL-6 and TNF- α, which is of special significance for modifying the middle-macromolecular cytokine level in the complicated human blood environment.