Additive-free preparation of hemodialysis membranes from block copolymers of polysulfone and polyethylene glycol

Hemodialysis membranes have been widely used for the treatment of chronic kidney disease. However, as common hemodialysis membranes, polysulfone based membranes are suffering from complicated modification to improve hemocompatibility and safety issues of additive leaching-out. Facing these challenges, here hemodialysis membranes with excellent hemocompatibility and biocompatibility were fabricated by nonsolvent induced phase separation (NIPS) of a block copolymer, polysulfone-block-poly(ethylene glycol) (PSF-b-PEG), without using any additives. During NIPS, mesopores were formed throughout the membrane and the PEG chains were preferentially enriched on surfaces, thus improving the hydrophilicity. In-vitro compatibility and performance of the PSF-b-PEG membranes as well as protein adsorption, hemolysis, platelet adhesion, ultrafiltration coefficient, solute rejection and toxin clearance were studied. Due to the intrinsic existence of hydrophilic and biocompatible PEG on surface, the PSF-b-PEG membranes exhibited superior hemodialysis performances than traditional membranes, demonstrating their promise for hemodialysis.