A Vascularized Liver Microphysiological System Captures Key Features of Hepatic Insulin Resistance and Monocyte Infiltration
Three-dimensional in vitro liver models are a promising means to recapitulate key aspects of human liver disease pathologies, thereby aiding therapeutic development. Spheroidal aggregates of hepatocytes, sometimes including non-parenchymal cells, are an established approach for modeling facets of metabolism and drug responses, yet these models often lack dynamic interactions with vascular and immune cells that also contribute to disease development and progression. To address this, we developed a microphysiological system (MPS) that integrates multicellular human hepatic spheroids with self-organized microvascular networks. We show extensive interaction between primary human spheroids and functional vasculature while maintaining key hepatic functions. We demonstrate the utility of this MPS by modeling an insulin resistance state through chronic exposure to disease-mimetic media conditions. This disease model displays altered hepatocyte metabolism, dysregulated vascular features, and increased inflammation state. Enabled by the functional vasculature, we further extend this disease model to capture changes in immune cell recruitment. When culturing CD14+ monocytes in our liver MPS, a subset of monocytes extravasate, localize to hepatic spheroids, and begin differentiating into CD163+ macrophages. These cells infiltrate with greater frequency in insulin resistant samples, consistent with known clinical findings. All together, this vascularized MPS model captures disease-relevant liver biology including inflammatory features.