Magnetostaltic pumping in an ex vivo extracorporeal membrane oxygenation model

Extracorporeal membrane oxygenation (ECMO) is a critical rescue therapy for severe respiratory or cardiac failure. However, current blood pumps generate high shear stresses that can damage blood components, leading to hemolysis, loss of von Willebrand factor multimers, and increased risks of bleeding, thrombosis, and organ injury. We developed novel magnetostaltic pumps that use magnetic liquid interfaces instead of solid walls to transport blood, aiming to reduce mechanical stress on blood cells. Four magnetostaltic pump designs were tested in ex vivo ECMO circuits using human donor blood at clinically relevant flow rates and compared with standard centrifugal and peristaltic pumps. Across all flow rates, magnetostaltic pumps produced less hemolysis than conventional pumps. Under pediatric flow conditions (1 L/min for 48 h), the large-scale magnetostaltic pump (QR3) reduced hemolysis by approximately one-third compared with commercial centrifugal pumps and preserved high-molecular-weight von Willebrand factor multimers. Platelet function was unaffected. Small amounts of nanoparticle leakage from the magnetic fluid were detected but remained well below toxic thresholds. Magnetostaltic pumping offers a promising alternative to current ECMO pumps by reducing blood damage. These results support further testing in animal models to evaluate the potential for clinical translation.