Vitamin E-Coated Super High-Flux Membranes: Toward Enhanced Middle Molecule Removal and Improved Biocompatibility

End-stage renal disease is characterized by the accumulation of uremic toxins, chronic inflammation, and heightened oxidative stress, all of which contribute to high morbidity and mortality among hemodialysis (HD) patients. Although conventional HD effectively removes small solutes, inadequate clearance of large middle molecules remains a major therapeutic limitation. The development of medium cut-off and super high-flux (SHF) membranes has enabled enhanced removal of large middle molecules within the framework of Expanded Hemodialysis (HDx). In parallel, strategies aimed at improving membrane biocompatibility, particularly vitamin E-coated membranes, have been developed to mitigate inflammation and oxidative stress production triggered by the interaction between blood and dialysis membranes. This review summarizes the effects of HDx on the removal of middle molecules, and outlines emerging evidence supporting vitamin E-coated SHF membranes as an approach to combine improved middle molecules clearance with enhanced biocompatibility.