Analysis of IL-6 and IL-1β Gene coding and study on specific clearance using histidine-grafted PVDF membranes

Severely infected patients produce large amounts of inflammatory cytokines, such as interleukin-6 (IL-6) and interleukin-1β (IL-1β), leading to a "cytokine storm", which is a clinically refractory condition. Because IL-6 and IL-1β differ significantly in gene family, chromosomal location, protein structure, and signaling pathways, existing techniques are ineffective at simultaneously removing cytokines. This work developed a novel blood purification material by chemically grafting histidine onto a polyvinylidene fluoride (PVDF) membrane. ATR-FTIR and XPS analyses confirmed the successful grafting of histidine onto the PVDF membrane. Following histidine grafting, the membrane's adsorption capacity for IL-6 in aqueous solution increased with histidine concentration. The optimized histidine-grafted PVDF membrane achieved adsorption rates of (36 ± 4)% for IL-6 and (63 ± 5) % for IL-1β in plasma. Additionally, the histidine-grafted PVDF membrane demonstrated enhanced biocompatibility, exhibiting a low hemolysis rate, minimal adsorption of red blood cells and platelets, and anticoagulant properties without activating the coagulation cascade. This histidine-grafted PVDF membrane offers a promising new therapeutic strategy for treating severe infections and holds significant potential for clinical application.