Heparin/polyethyleneimine dual-sided functional polyvinylidene fluoride plasma separation membrane for bilirubin removal

Herein, a novel heparin/polyethyleneimine (PEI) dual-sided functional polyvinylidene fluoride (PVDF) plasma separation membrane structure is proposed. Bilirubin is removed using this membrane via one-step "anticoagulation-adsorption". When blood flows in the membrane, the inner side of the membrane can prolong clotting time. Meanwhile, bilirubin contained in plasma is filtrated through the membrane. Bilirubin is adsorbed on the outer side of the membrane to be removed. Herein, branched PEI was grafted on the outer side of the PVDF plasma separation membrane to construct the bilirubin adsorption functional layer. Then, heparin was grafted on the inner side to construct a self-anticoagulant functional layer. The dual-sided functional PVDF plasma separation membrane was prepared. The results showed that PEI and heparin could be grafted on the outer side and the inner side of the PVDF plasma separation membrane, separately. Bilirubin's competitive adsorption property of the outer side of the membrane was enhanced. Hemocompatibility of the inner side of the membrane was strengthened. The plasma permeability of the novel membrane gradually decreased to 250 L·m−2·h−1bar−1. The total plasma protein sieving coefficient of the novel membrane was larger than 80 %. Total bilirubin and direct bilirubin adsorption capacity reached 22.5 mg/g and 20.5 mg/g via one-step "anticoagulation-adsorption". The novel membrane prepared in this work can effectively simplify traditional hemoperfusion therapy, implying its great potential application.