Supermacroporous cryogel membranes via polyethyleneimine-assisted decoration for efficient removal of bacterial endotoxin

The endotoxin, which is a highly pathogenic toxin released from the cell wall of gram-negative bacteria after death, can lead to critical diseases such as sepsis and intestinal inflammation. Poly 2-hydroxyethyl methacrylate (HEMA)-glycidyl methacrylate (GMA)/polyethyleneimine (PEI) cryogel membranes employed for endotoxin removal were synthesized via the immobilization of PEI solution with poly(HEMA-GMA) membranes. The concentration of the treated PEI% solution, the concentration of the endotoxin solution, and the ambient temperature influenced the endotoxin binding percentage of poly(HEMA-GMA) cryogel membranes. Maximum endotoxin removal was observed with poly(HEMA-GMA) cryogel membranes treated with a 25 % PEI solution at 25 °C. Additionally, it was noted that poly(HEMA-GMA)/PEI cryogel membranes exhibited increased endotoxin binding with rising endotoxin concentrations. The percentage of endotoxin bound by cryogel membranes in both aqueous solutions and artificial plasma media increases with the endotoxin concentration in the solutions. The Limulus Amebocyte Lysate (LAL) assay results show that the percentages of bound endotoxin in artificial plasma and aqueous solutions are approximately equivalent. The prepared poly(HEMA-GMA)/PEI adsorbent exhibited good reusability and offered high removal ability for endotoxin. The adsorption process can be accurately described by Langmuir adsorption isotherm model.