Histidine-inspired polyacrylonitrile-based adsorbent with excellent hemocompatibility for the simultaneous removal of bacteria and endotoxin in septic blood

Endotoxins (LPS) are components of the cell wall of Gram-negative bacteria that are released when bacterial cell membrane is destroyed, the bacteria and the released LPS have led to serious diseases such as sepsis and septic shock. Histidine functionalized adsorbents have been used to remove LPS, however, the present hemoperfusion adsorbents have drawbacks such as inadequate LPS adsorption capability, high cost of raw material, and so on. Inspired by the structure of histidine and incorporated antibacterial molecules, we synthesize allylamine-modified polyacrylonitrile (PAD)/poly (imidazolium bromide) (PMIBr) composite (PAI) microspheres as hemoperfusion adsorbents. The PAI microspheres show excellent antibacterial ability with high killing efficiency of 98.8% against S. aureus and 95.4% against E. coli. In addition, the adsorption capacity of the microspheres for LPS in PBS is 433.5 EU/g within 3 h, and the LPS concentration could also be reduced from 7.34 EU/mL to below 0.5 EU/mL in the plasma environment. The PAI microspheres exhibit outstanding blood compatibility, antibacterial property and endotoxin removal capability, which have great potential in the treatment of sepsis patients.