Heparin-mimicking semi-interpenetrating composite membrane with multiple excellent performances for promising hemodialysis

Abstract

Natural heparin macromolecule has been widely used to improve the hemocompatibility of biomaterials. However, heparin can cause spontaneous bleeding in some patients, which is troublesome for clinical applications. Fortunately, analogous heparin polymers have shown promise to replace heparin. Here a new class of composite polyethersulfone (PES) membranes were constructed, which offered tunable permeability together with excellent hemocompatibility via incorporating heparin-mimicking semi-interpenetrating polymer. The polyurethane macromer was synthesized as an effective cross-linker to incorporate functional polyacrylic acid and poly-2-acrylanmido-2-methylpropanesulfonic acid segments into PES solution through in-situ cross-linking polymerization. Then the heparin-mimicking semi-interpenetrating composite PES membranes were fabricated from the resulting casting solution via alkali-induced phase separation technique. The resulting composite membranes showed excellent inhibition of protein adsorption, suppression of platelet adhesion, reduction of hemolysis ratio and prolongation of clotting times, while displayed high hydrophilicity, permeability and clearance to urea, creatinine and lysozyme. Interestingly, the composite membranes also exhibited excellent mechanical properties due to the synergistic effect of polyurethane composition and in-situ cross-linking copolymerization. To further demonstrate the applicability and effectiveness of this method, a composite PES hollow fiber with excellent ultrafiltration and mechanical properties was also fabricated. This straightforward and facile method is constructed as an ideal candidate to suppress blood clotting for a range of blood purification membrane-related applications.