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Abstract: SA-PO554

Hydrophilic Membrane Modification Improves Filtration Characteristics of Dialyzer Membranes

Session Information

Category: Dialysis

  • 801 Dialysis: Hemodialysis and Frequent Dialysis


  • Kennedy, James Paul, Fresenius Medical Care North America, Ogden, Utah, United States
  • Förster, Eva, Fresenius Medical Care Deutschland GmbH, Sankt Wendel, Germany
  • Saremi, Saeedeh, Fresenius Medical Care Deutschland GmbH, Sankt Wendel, Germany
  • Theis, Lukas, Fresenius Medical Care Deutschland GmbH, Sankt Wendel, Germany
  • Küng, Florian, Fresenius Medical Care Deutschland GmbH, Sankt Wendel, Germany
  • Delinski, Dirk, Fresenius Medical Care Deutschland GmbH, Sankt Wendel, Germany
  • Xie, Wenhao, Fresenius Medical Care R&D (Shanghai) Co., Ltd., Shanghai, China
  • Faust, Matthias, Saarland University of Applied Sciences, Saarbrücken, Germany
  • Zawada, Adam M., Fresenius Medical Care Deutschland GmbH, Sankt Wendel, Germany

While efficient removal of uremic solutes and accumulated water is pivotal for the well-being of patients requiring kidney replacement therapy, the removal capacity of a dialyzer decreases during dialysis treatment due to adsorption of plasma proteins to the membrane. Hydrophilic membrane modification with polyvinylpyrrolidone (PVP) has been shown to reduce protein adsorption and to stabilize permeability of the membrane during treatment. The present study compares water permeability changes of polysulfone membranes, including the PVP enriched and stabilized membrane of the novel FX CorAL dialyzer.


This in vitro study included the polysulfone-based FX CorAL 600, FX CorDiax 600 (both Fresenius Medical Care) and xevonta Hi15 (B. Braun) dialyzers. Protein fouling to the membrane was simulated during a recirculation experiment with bovine milk for 4h. The decrease in filtration flow (QF) at constant inlet flow (QIN, 400ml/min) and transmembrane pressure (TMP, 75mmHg) (setup 1) as well as the increase in TMP at constant QF (100ml/min) and QIN (400ml/min) (setup 2) were continuously determined during recirculation.


Across all dialyzers, QF at constant QIN and TMP decreased strongly in the first 20min and then slowly for the remaining time (20min: -50.8±15.9ml/min; 4h: -66.9±29.2ml/min). Likewise, the TMP at constant QF and QIN increased first strongly and then slowly (20min: +21.9±3.9mmHg; 4h: +39.0±5.9mmHg). The FX CorAL showed the lowest reduction in QF (20min: -30.6±8.2ml/min; 4h: -32.6±13.4ml/min) as compared to FX CorDiax (20min: -61.0±3.7ml/min, p=0.001; 4h: -78.2±21.4ml/min, p=0.017) and xevonta (20min: -60.8±3.4ml/min, p=0.001; 4h: -90.0±5.5ml/min, p=0.006). In line, the FX CorAL showed lowest increase in TMP (20min: +18.3±1.5mmHg; 4h: +32.7±2.1mmHg), as compared to the FX CorDiax (20min: +21.7±3.8mmHg, p=0.214; 4h: +39.9±4.8mmHg, p=0.078) and xevonta (20min: +25.8±0.8mmHg, p=0.015; 4h: +44.4±3.0mmHg, p=0.011).


Protein adsorption to the membrane is the major factor for the initial decrease of dialyzer membrane permeability during hemodialysis. Hydrophilic membrane modification with PVP reduces protein fouling and stabilizes the removal capacity of solutes and water during dialysis treatment.