Heparinized thin-film composite membranes with sub-micron ridge structure for efficient hemodialysis

Hemodialysis membranes are critical components for hemodialysis process. Herein, we demonstrate a new kind of hemodialysis membrane based on polyacrylonitrile (PAN) electrospun scaffold and heparin-poly(vinyl alcohol) (heparin-PVA) hydrogel coating. Manipulation of coating solution rheology by control of heparin content enabled the creation of membranes with sub-micron ridged surface topography. The results of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra confirmed that heparin was covalently incorporated in the hydrogel layer; meanwhile, the scanning electron microscopy (SEM) and atomic force microscopy (AFM) images gave clear evidence that the fabricated membranes had typical sub-micron ridge structure. The results revealed that the sub-micron ridged surface topography and heparin chemical modification synergistically endowed the membranes with excellent permeability, protein antifouling properties, anticoagulant activity, cytocompatibility, and dialysis performances. Especially, when the heparin/PVA weight ratio was 20%, the water flux of the membrane was 371.8 L/m²h. Its urea clearance was 86 mL/min, lysozyme clearance was 60 mL/min, and bovine serum albumin clearance was as less as 5.5 mL/min.