Enhanced hemocompatibility of flat and hollow fiber membranes via a heparin free surface crosslinking strategy

Insufficient hemocompatibility is challenging for current dialysis membranes. The current modification methods have some limitations in effectiveness, practicality and cost. Herein, we develop a heparin-free crosslinking approach to enhance the hemocompatibility of both the flat (polylactide) and hollow fiber (polysulfone) membranes with heparin-mimicking surface. Poly (triethoxyvinylsilane-N-vinyl-2-pyrrolidone) (P (VTES-VP)) is first introduced to the membrane surface to improve the hydrophilicity, which is facilitated to the adsorption and further crosslinking of poly (triethoxyvinylsilane-Acrylic acid-Sodium 4-vinylbenzenssulfonate) (P(VTES-AA-SSNa)). The mixture of N, N-dimethylacetamide (DMAc) and water was modulated for good solubility, swelling and adsorption of precopolymer. The chemical structure of the heparin-mimicking membrane was confirmed by attenuated total reflectance Fourier transform infrared spectra (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), weight measurement and scanning electron microscopy (SEM). The hydrophilicity was improved by the heparin-mimicking surface. Moreover, the heparin-mimicking membranes presents higher platelet resistance, prolonged coagulation time (APTT for ~ 180.1 s), decreased Plasma fibrinogen (FIB for ~ 122 mg/dL), and suppressed complement activation. More importantly, the heparin-free crosslinking approach can be utilized to significantly enhance the hemocompatibility of commercial PSF hollow fiber membranes, indicating its potential application in heparin free dialyzers.