High-performance porous liquid composite hollow fiber membranes for enhanced CO₂ removal in artificial lungs

The low CO₂ removal efficiency of gas-blood exchange membranes posed a significant challenge of CO₂ retention in extracorporeal membrane oxygenation (ECMO). To address this, a novel strategy was pioneered through the integration of a Type III MOF-based porous liquid (UiO-66-PLs) with the biopolymer chitosan (CS) to fabricate a hemocompatible composite membrane, effectively overcoming the common issue of nanofiller agglomeration in traditional mixed-matrix membranes. A PDMS/PLs-CS mixed matrix composite membrane (MMCM) was successfully fabricated based on a PMP hollow fiber substrate. Experimental results demonstrated that the optimized CO₂/O₂ selectivity of the composite membrane reached 5.16, 2.0 times of the pristine PMP gas-blood exchange membrane. Simultaneously, the composite membrane exhibited excellent anti-blood cell adhesion and anti-protein adsorption properties (from 54.6 μg/cm 2 to 29.6 μg/cm 2 ). The material demonstrated no adverse effects on blood or tissue cells and maintained stable hydrophobicity and antifouling performance over 14 days. Crucially, blood circulation and rabbit model experiments confirmed that the composite membrane provides comparable oxygenation while delivering significantly superior CO₂ removal efficiency. This study presents the first demonstration of integrating Type III MOF-based porous liquids with biopolymers such as chitosan for fabricating hemocompatible composite membranes, offering a promising solution to enhance CO₂ clearance in ECMO applications.