Towards a Biohybrid Lung? Impacted Endothelial Layer Integrity in Inflammatory Conditions

Limited hemocompatibility, inflammation, and sepsis are frequent complications during extracorporeal membrane oxygenation (ECMO). Endothelialisation of gas exchange membranes has been proposed to overcome these limitations and general feasibility has been demonstrated. However, these investigations used biohybrid devices under standard in vitro culture conditions neglecting patients’ inflammatory status in clinics. In this study, we investigate human umbilical vein endothelial cell (HUVEC) behaviour on gas exchange membranes under inflammatory conditions in a microfluidic model system using immunocytochemistry, scanning electron microscopy, flow cytometry, and qPCR. While co-culture with healthy control peripheral blood mononuclear cells (PBMCs) does not change endothelial layer integrity, confluence of the endothelial layer is substantially reduced upon inflammation via lipopolysaccharide (LPS) activated PBMCs. Cell adhesion molecules are increasingly expressed under inflammatory conditions, consistent with an increased leukocyte adhesion. An upregulation of several genes linked to inflammation is observed: ICAM-1, VCAM-1, E-Selectin, IL6, IL8, IL10, and MCP-1. Our findings suggest that endothelial cells struggle to maintain their layer integrity within a biohybrid device when exposed to inflammatory conditions. This raises the question of whether endothelialisation is an effective advancement of current technologies considering the frequent inflammatory status in ECMO patients. Yet the presented setup qualifies as sepsis in vitro model replicating the physiological vascular leak phenomenon to aid future investigations in biohybrid lung research. ### Competing Interest Statement The authors have declared no competing interest.