Vitamin E–coated Super High-Flux Membranes: Towards Enhanced Middle Molecule Removal and Improved Biocompatibility.

Hemodialysis (HD) patients are exposed to the accumulation of uremic toxins, chronic inflammation, and oxidative stress, which contribute to increased morbidity and mortality. Advances in the identification of a broad spectrum of middle molecules with a molecular mass >15 kDa have highlighted their substantial deleterious role. Consequently, enhanced removal of these larger middle molecules has become a key therapeutic objective. To improve middle molecules clearance, medium cut-off (MCO) membranes and type V super high-flux (SHF) membranes were developed. These membranes combine increased pore size cut-off and internal filtration and are now categorized as Expanded Hemodialysis (HDx). Beyond uremic toxin accumulation, the interaction between blood and the dialysis membrane itself remains a key driver of inflammation and oxidative stress. Repeated exposure to artificial materials during HD may result in sustained immune activation, contributing to various complications and increased mortality. Accordingly, strategies aimed at improving membrane biocompatibility have been developed. Vitamin E, a lipophilic antioxidant that scavenges reactive oxygen species and prevents lipid peroxidation, has been applied as a blood-membrane surface modification strategy. Vitamin E–coated membranes have been specially designed to improve membrane biocompatibility. Recently, a novel vitamin E–coated SHF membrane has been launched to combine enhanced middle molecules removal with improved biocompatibility.