Research on dialyzers with improved biocompatibility.

Until now cellulosic membranes, especially Cuprophan, are still widely applied in the treatment of uremic patients. The success of this type of membrane for routine hemodialysis is related to a number of very useful properties with respect to performance, handling and biocompatibility. However, during dialysis Cuprophan membranes induce transient leucopenia which is closely connected with incidentally occurring pulmonary disfunction. These phenomena are thought to be complement mediated and Cuprophan has been recognized as an activator of complement. Synthetic membranes, such as PAN and PMMA show less complement activation than their cellulosic counterparts. Nevertheless these synthetic membranes cannot meet the performance quality of Cuprophan for routine dialysis and therefore dialyzers with synthetic membranes need special precaution to prevent excessive ultrafiltration. Consequently, research has been focussed on the development of a new cellulose-based dialyzer in which excellent performance suitable for routine dialysis is combined with improved biocompatibility. Two different approaches have been followed for the realization of this objective: The application of thinner membranes and The application of modified cellulose.