Hemodialysis membrane surface chemistry as a barrier to lipopolysaccharide transfer

During hemodialysis bacterial lipopolysaccharide (LPS) in contaminated dialysate solution may translocate across the hollow fiber membrane (HFM) to a patient's blood, resulting in fever and possible systemic shock. This study investigates LPS transfer across, and adsorption within, native and modified Fresenius Optiflux® F200NRe polysulfone (PS)/polyvinyl pyrrolidone (PVP) HFMs. Modifications include varied PVP content, addition of a PS-poly(ethylene glycol) copolymer (PS-PEG), and bleach sterilization. Under clinically relevant flow conditions LPS from >400 EU mL−1 spiked dialysate is not detected (<0.1 EU mL−1) in the lumens of native fibers, but is detected to varying degrees (0.2–15 EU mL−1) in the lumens of the modified fibers. Fluorescently labeled LPS predominantly adsorbs near the lumen of all membranes except the PS-PEG containing membrane, where LPS localizes on the outer wall. Thus, addition of PS-PEG may entrap LPS in the HFM spongy matrix, away from the blood-contacting fiber lumen. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41550.