Efficacy of a novel endotoxin adsorber polyvinylidene fluoride fiber immobilized with L-serine ligand on septic pigs

A novel adsorber, polyvinylidene fluoride matrix immobilized with L-serine ligand (PVDF-Ser), was developed in the present study to evaluate its safety and therapeutic efficacy in septic pigs by extracorporeal hemoperfusion. Endotoxin adsorption efficiency (EAE) of the adsorber was firstly measured in vitro. The biocompatibility and hemodynamic changes during extracorporeal circulation were then evaluated. One half of 16 pigs receiving lipopolysaccharide (Escherichia coli O111:B4, 5 mu g/kg) intravenously in 1 h were consecutively treated by hemoperfusion with the new adsorber for 2 h. The changes of circulating endotoxin and certain cytokines and respiratory function were analyzed. The 72 h-survival rate was assessed eventually. EAE reached 46.3% (100 EU/ml in 80 ml calf serum) after 2 h- circulation. No deleterious effect was observed within the process. The plasma endotoxin, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) levels were decreased during the hemoperfusion. Arterial oxygenation was also improved during and after the process. Furthermore, the survival time was significantly extended (> 72 h vs. 47.5 h for median survival time). The novel product PVDF-Ser could adsorb endotoxin with high safety and efficacy. Early use of extracorporeal hemoperfusion with the new adsorber could reduce the levels of circulating endotoxin, IL-6, and TNF-alpha, besides improve respiratory function and consequent 72 h-survival rate of the septic pigs. Endotoxin removal strategy with blood purification using the new adsorber renders a potential promising future in sepsis therapy.