Biomimetic gas channel constructed for efficient CO2 removal based on computational simulations

Membrane oxygenator performs lung function in the Extra-corporeal Membrane Oxygenation (ECMO) system. In the clinical use, to ensure the balance of gas exchange of patient's body, the gas-blood exchange membrane is required to possess CO₂/O₂ selectivity, which is suggested to be in the range of 10–12. In our work, the molecular dynamics simulation results displayed that the amino-functionalized Zr-MOFs provides fast transport channels for CO₂ molecules because of the enhancement of the adsorption and diffusion ability for CO₂. Therefore, we chose organic ligands with abundant CO₂-philic groups to synthesize target amino-functionalized Zr-MOFs, and then dispersed them into medical-grade PDMS solution to study the separation performance of CO₂/O₂. On the basis of constructing anti-leakage coating layer, biomimetic gas channels were designed to increase the clearance rate of CO₂. Experimental results exhibited that the CO₂/O₂ selectivity of (NH₂)₂-UiO-66/PDMS MMM was as high as 11.19, which was basically consistent with the simulation results. The obtained amino-functionalized Zr-MOF/PDMS coating layer displayed favorable biocompatibility and biosafety. Meanwhile, the construction of biomimetic channel solves the difficult problem of CO₂ removal in PMP membrane, which verifies the feasibility of applying porous materials to gas-blood exchange membranes in the ECMO system.