Abstract: TH-PO0481
Comparative Analysis of Hydrated Copolymer Layers in Hemodialyzer Membranes via Atomic Force Microscopy
Session Information
- Hemodialysis: Novel Markers and Case Reports
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Crook, Nathan S, Fresenius Medical Care North America, Ogden, Utah, United States
- Boyington, Skyler, Fresenius Medical Care North America, Ogden, Utah, United States
- Van Devener, Brian, University of Utah, Nanofab EMSAL, Salt Lake City, Utah, United States
- Dummer, Charles Wade, Fresenius Medical Care North America, Ogden, Utah, United States
- Hendricks, Darrell L, Fresenius Medical Care North America, Ogden, Utah, United States
- Kennedy, James Paul, Fresenius Medical Care North America, Ogden, Utah, United States
- Zawada, Adam M., Fresenius Medical Care Deutschland GmbH, St. Wendel, Saarland, Germany
Background
A dialyzer membrane is the major point of interaction with patient’s blood. A key factor influencing this interaction is the presence of a hydrolayer - a layer of water bound by hydrophilic polymers on the membrane surface - which plays a critical role in reducing protein adsorption and enhancing hemocompatibility. The FX CorAL dialyzer features a novel membrane with increased content of the hydrophilic polyvinylpyrrolidone (PVP) copolymer on the blood side surface. The present study investigates the impact of the increased PVP content on membrane hydrophilicity using Atomic Force Microscopy (AFM).
Methods
AFM measurements on open and hydrated fibers were performed using a Bruker ICON in wet mode to measure the thickness of the hydrated copolymer layer of the FX CorAL membrane (Fresenius Medical Care) as compared to other commercial dialyzer membranes (Optiflux [Fresenius Medical Care], ELISIO [Nipro], Revaclear [Baxter]. Force-distance curves were analyzed and hydrolayer thickness was measured using a custom MatLab application.
Results
All dialyzer membranes showed a hydrolayer, with the FX CorAL demonstrating the highest mean thickness (11.6±3.9nm), as compared to Optiflux (5.2±2.2nm, p<0.001), ELISIO (6.3±2.1nm, p<0.001) and Revaclear (5.7±3.8nm, p<0.001). Additionally, representative surface scans of wet fibers showed that the FX CorAL had the smoothest surface (Ra FX CorAL: 5.3, Optiflux: 6.4, ELISIO: 7.2, Revaclear: 12.8).
Conclusion
All dialyzer membranes exhibited a measurable hydrated copolymer layer. The FX CorAL membrane demonstrated the thickest hydrolayer, suggesting superior hydrophilicity as compared to the other investigated dialyzers. These findings help to understand previous experimental and clinical studies showing improved hemocompatibility and performance stability of the FX CorAL dialyzer during hemodialysis.
Funding
- Commercial Support – Fresenius Medical Care