Abstract 378: Lymphangion-chip: It Recreates Intercellular Signaling Between Lymphatic Vascular Endothelial And Mural Cells In Health And Disease

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The pathophysiology of several lymphatic diseases, such as lymphedema, depends on the function of lymphangions. Even though the signaling between two main cellular components of a lymphangion, Lymphatic Endothelial Cells (LECs) and Lymphatic Muscle Cells (LMCs), is responsible for crucial functions, there are no in vitro models that have included both cell types in a physiologically relevant environment. Here, a fabrication technique is developed to create a Lymphangion-Chip. This organ-on-chip consists of co-culture of a monolayer of endothelial lumen surrounded by multiple and uniformly thick layers of muscle cells. The platform allows construction of a wide range of luminal diameters and muscular layer thicknesses, thus providing a toolbox to create variable anatomy. In this device, the muscle cells align circumferentially while endothelial cells aligned axially under flow, as only observed in vivo in the past. This model further demonstrated a robust sensitivity of this relative alignment of the two cells as well as dynamics of cell size, density, growth, and intercellular gap with respect to the presence or absence of co-culture and mechanical forces (shear). The time-dependent decrease in the subendothelial gap strongly suggests proactive LEC-LMC signaling as LECs and LMCs grow and proliferate within the device. Further exposure to pro-inflammatory cytokines reveals that the device could produce the regulation of endothelial barrier function through the muscle cells. Finally, measurement of intracellular calcium of LECs and LMCs while exposed to step and oscillatory flow profiles with various shear amplitudes revealed the bidirectional mechanism of calcium signaling within the platform. Therefore, this technology allows researchers to include essential lymphatic vascular components in a tunable 3D microphysiological system that is suitable for use in preclinical research of lymphatic mechanobiology, inflammation, and translational outcomes.