Three-dimensional membranes for artificial lungs: Comparison of flow-induced hemolysis

Background Membranes based on triply periodic minimal surfaces (TPMS) have proven a superior gas transfer compared to the contemporary hollow fiber membrane (HFM) design in artificial lungs. The improved oxygen transfer is attributed to disrupting the laminar boundary layer adjacent to the membrane surface known as main limiting factor to mass transport. However, it requires experimental proof that this improvement is not at the expense of greater damage to the blood. Hence, the aim of this work is a valid statement regarding the structure-dependent hemolytic behavior of TPMS structures compared to the current HFM design. Methods Hemolysis tests were performed on structure samples of three different kind of TPMS-based designs (Schwarz-P, Schwarz-D and Schoen's Gyroid) in direct comparison to a hollow fiber structure as reference. Results The results of this study suggest that the difference in hemolysis between TPMS membranes compared to HFMs is small although slightly increased for the TPMS membranes. There is no significant difference between the TPMS structures and the hollow fiber design. Nevertheless, the ratio between the achieved additional oxygen transfer and the additional hemolysis favors the TPMS-based membrane shapes. Conclusion TPMS-shaped membranes offer a safe way to improve gas transfer in artificial lungs.

Automated summary

Membranes based on TPMS structures have shown superior gas transfer compared to contemporary HFM designs in artificial lungs, attributed to disrupting the laminar boundary layer near the membrane surface. Hemolysis test results indicate that although there is a slight increase in hemolysis for TPMS membranes, the difference compared to HFMs is small. The ratio between additional oxygen transfer and additional hemolysis favors the TPMS-based membrane shapes, suggesting a safe way to improve gas transfer in artificial lungs.