Abstract
The surface roughness due to the pore size distribution of dialysis membranes, surface texture, relative stiffness or rigidity are some of important parameters of the membrane surface that directly or indirectly affects the quality and reliability of the dialysis devices or hemodialyzers. Hemocompatibility due to its interaction with blood cells, proteins, and platelets of blood being filtered find weighted relevance when it comes to quality and reliability of dialysis membranes. We obtained hollow fiber dialysis membrane from four selected hemodialyzers of different makes presently being used at dialysis centers across the kingdom of Saudi Arabia. The membrane fiber samples were prepared for nano-characterization on its outer and inner surfaces using atomic force microscope (AFM). The nano-images of the membrane surfaces were recorded using peak force quantitative nanomechanical (PF-QNM) mode. Using the offline software for AFM image analysis, we analyzed the membranes under study for the surface roughness and relative stiffness that are supposedly important parameters affecting overall hemocompatibility and particularly hemolysis. A comparative analysis of the surface nano-features in terms of root-mean-square value (Rq) of surface roughness and relative stiffness or Young's modulus (DMT modulus) obtained for different makes of the membrane fibers are presented in this part of the work. Our preliminary results using one hemodialyzer brand with luminal roughness (Rq=8.9 +/- 1.5 nm) suggest that the patients' hematocrit values go down at the end of dialysis session which is indicative of hemolysis. The second part of this work (not included) with additional relevant hematological data (analysis in progress) may further demonstrate compatibility issues affected by nanomechanical properties of the membranes.