Heparin reduced dialysis through a facile anti-coagulant coating on flat and hollow fiber membranes

Heparin free prescription is highly desired for haemodialysis. Versatile strategies have been developed to address the anti-coagulation modification of dialysis membranes. We here develop a facile and effective method to construct an anticoagulant coating on polymeric membranes or a dialyzer through hydrophobic-hydrophobic interaction. An amphiphilic heparin-like copolymer was first synthesized via a free radical polymerization based on alkyl chain lauryl methacrylate (LMA), acrylic acid (AA), and sodium 4-vinylbenze-sulfonate (SSNa) segments. The specific structure of terpolymer was characterized via Fourier transform infrared spectra (FTIR), Proton nuclear magnetic resonance (H-1 NMR) spectra and size exclusion chromatography (SEC). The amphiphilic copolymer was anchored onto Polylactide (PLA) membrane surface from an aqueous-based solution via hydrophobic-hydrophobic interaction. An Attenuated total reflectance Fourier transform infrared spectra (ATR-FTIR), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) confirmed the successful immobilization of heparin-mimicking terpolymers. The modified membranes showed excellent antifouling property and hydrophilicity. Moreover, the membranes exhibited outstanding haemocompatibility with suppressed platelet adhesion, low complement activation (C3a and C5a), expanded coagulation time and limited haemolysis ratio. The prolonged activated partial thromboplastin time and thrombin time (APTT>600 s, TT > 140 s) certified the excellent self-anticoagulant performances. To further examine the applicability and effectiveness, a polysulfone dialyzer was modified by this strategy. The ultrafiltration coefficient and clearance performances were examined. Overall, the hydrophobic-hydrophobic interaction strategy simplified the modification procedure of dialysis membrane, implying its great potential in heparin free dialysis application.