Surface Dual-Functionalized Design of Polyester Fiber Membrane for the Clearance of Bilirubin in Blood

Bilirubin, a potent endogenous toxin, can cause irreversible damage to the brain and nervous system. To address this, we developed a novel polydopamine/polyethylenimine (PDA/PEI)-functionalized polyester fiber (PDA/PEI–PF) membrane capable of plasma separation and bilirubin adsorption properties. The surface macropores of the PDA/PEI–PF membrane were filled with PDA particles, followed by PEI grafting to generate a positive charge. The optimized PDA/PEI–PF membrane exhibited acceptable plasma permeance of ∼2.5 L m–2 h–1 for diluted blood, along with a high cell retention rate (∼90%), a low hemolysis rate (∼2.7%), and excellent blood compatibility (hemolysis rate, ∼0.3%). Additionally, the bilirubin retention capacity of the PDA/PEI–PF membrane can reach 68.56 μg cm–2 and 270.33 μg cm–2 for static and dynamic adsorption processes, respectively. The novel “screening–adsorption” membrane prepared in this study may streamline traditional blood perfusion therapy, demonstrating significant potential for clinical applications.