WAT-liver chip with integrated sensors to study human white adipose and hepatic tissue crosstalk

Abstract

Organ-on-chip (OoC) technology has made rapid progress over the last decade with advances in microfabrication techniques, cell culture, biomarker analysis techniques and more importantly, considerations about the predictability, scalability, and standardization of the models. Given the complex and chronic nature of metabolic diseases involving the interactions of multiple organs, MOCs represent a new class of preclinical models aimed at fulfilling the 3Rs (reduction, replacement, refinement) of animal testing for mechanistic toxicity or disease modelling. The goal of this thesis was the development of novel MOC platform technology to connect two organ-chips with integrated sensors and ancillary features to introduce biological complexity in the model. A modular, flexible MOC connection platform with 3D printed modular inserts and chips was developed and characterized. Sensors were integrated into the platform, which also supported a recirculation perfusion regime. The WAT- and liver-chips were designed and standardized to fit into the cassette, where tissue channels were scaled relative to each other, and tissue structure enabled vascular connection in the cassette. Both chips were fabricated from rigid plastics and TPE considering minimal small molecule absorption. The system could measure glucose and oxygen consumption in the cassette during perfusion relative to blank chips without hepatocytes. When the liver-chip were connected to the WAT-chips, lipid droplets accumulated to a higher extent in the hepatocytes of the connected setup compared to those in unconnected liver-chips. A liver-sinusoid-on-chip model was developed to add a gradient of dissolved species (glucose, insulin, glucagon and oxygen) into media perfused across hepatocytes. To support long-term circulation of immune cells across the MOC platform, a prototype of an immune cell reservoir was designed and fabricated to allow for simple integration with the platform. Finally, considerations were made about requirements for the preparation of documentation according to regulatory guidelines keeping the goal of the 3Rs in view. The topics of this thesis collectively address the long-term culture and interaction of tissues (in this case white adipose tissue and hepatic tissue), with ancillary features, facilitating real-time monitoring of the onset and development of chronic metabolic diseases, and investigations of potential therapies for them.

Die Dissertation ist gesperrt bis zum 31. Dezember 2925 !