Studies of the Surface of Capillaries of Dialyzers with Atomic Force Microscopy

Abstract

Microstructural properties of polymeric materials applied as membranes seem to be a potential factor influencing the biocompatibility of capillary dialyzers. The aim of our preliminary studies was the microscopic evaluation of the inner surface of cuprophane (CU) and polysulfone (PSU) membranes. Gambro GFE09 (CU) and Fresenius F4 (PSU) dialyzers were investigated using AFM ( Fig.1 and Fig.2 respectively ) and the optical measurement system (OMV) . The analysis of AFM images allowed to determine the average diameter of channels on the surface of the inner part of the dialyzer capillary (D) and the roughness (RMS) of the inner surface, which were as follows (in nm): Table 1. Table 1: D RMS Gambro GFE09 180 40 - 65 Fresenius F4 390 39 - 48 It can be concluded that the higher roughness and smaller, diameters of the channels in cuprophane may be the reason of the decreased biocompatibility of this membrane as compared to polysulfone.