Facile hydrothermal synthesis of branched polyethylenimine grafted electrospun polyacrylonitrile fiber membrane as a highly efficient and reusable bilirubin adsorbent in hemoperfusion.

Bilirubin is a pathogenic toxin in the blood of patients with liver failure, and bilirubin adsorbents have been applied to remove the extra bilirubin in hemoperfusion. However, the developing of high-performance adsorbents with satisfying removal ability, physical/chemical stability, biocompatibility and hemocompatibility still needs to be explored. In this study, branched polyethylenimine (bPEI) grafted electrospun polyacrylonitrile (PAN) fiber membrane (bPEIPANFM) was fabricated via a green hydrothermal process. The hydrothermal temperature, hydrothermal time and the weight ratio of bPEI to PAN were investigated to seek the optimal bilirubin adsorption capacity. The results revealed that bPEIPANFM (hydrothermal temperature at 160 °C, hydrothermal time at 10 h and the weight ration of bPEI to PAN at 10:1) showed the best removal ability toward bilirubin. Batch adsorption experiments for both free bilirubin solution and bovine serum albumin (BSA)-bonded bilirubin solution were studied. The maximum adsorption capacity of bPEIPANFM toward BSA-bonded bilirubin was 112.87 mg/g, which is higher than those of many reported adsorbents. After ten regeneration cycles, the removal efficiency could still maintain 95%. Moreover, the bPEIPANFM also exhibited excellent biocompatibility and hemocompatibility. These obtained results demonstrate that this study may provide a new adsorbent for removing bilirubin in hemoperfusion applications.