Using a novel, adipose-liver, two-organ, human-on-a-chip system, the metabolic disease non-alcoholic fatty liver disease was modeled. This model was then used to test the effects of the gut microbiome on NAFLD progression. Two products of the gut microbiome, Trimethylamine-n-oxide and butyrate, were selected as representatives of potentially harmful and potentially beneficial compounds. A dose response, adipocyte and hepatocyte monocultures controls, and HoaC systems were run for 14 days. Through this experimentation, it was found that a dysbiosis of the gut microbiome could be influencing NAFLD progression. Additionally, further development and discovery regarding adipose-liver systems was added to the ongoing conversation of HoaC systems and their usages.

The drug development process is lengthy and expensive, with a 90% failure rate among drugs entering clinical trials due to the inadequacy of predictive models in the initial phases of drug development. To overcome these limitations, there is a paradigm shift towards developing micro physiological systems often referred as Organ-on-a-Chip that have be shown to recapitulate organ level functions in vitro. However, despite their promise, these systems often have limited throughput, restricting their widespread use in the drug development process. The work outlined in this thesis aims to bridge this gap by integrating the physiological relevance offered by micro physiological systems with the high throughput capabilities of traditional 2D multi-well plate cultures. The thesis outlines the development of two novel micro physiological systems, engineered in a high throughput multi-well format called the IFlowPlate and AngioPlate. Both the platforms have an open-top design and unlike tradition microphysiological platforms does not need complex pump systems and have built-in connections to achieve perfusion making it more scalable and user-friendly. The IFlowPlate leverages the self-assembly capability of endothelial cells to create a perfusable vascular network. This platform technology was utilized in this work to achieve intravascular perfusion of colon organoids for the first time and demonstrated immune cell circulation and recruitment in response to injury. AngioPlate, the other platform that was developed as a part of this work, utilizes a pre-patterned scaffold completely embedded in native hydrogel matrix to guide cells in forming organ-specific geometries and tubular structures using a novel subtractive manufacturing technique. This platform allowed for fabricating complex and intricate networks to model vascularized terminal lung alveoli and renal proximal tubules. This work demonstrated for the first time that highly complex perfusable tissues embedded in hydrogel can be integrated with multi-well plates to mimic tissue specific structures and interfaces without the use of synthetic membranes or plastic channels. The built-in perfusion channel and the flexible hydrogel matrix allowed for the terminal lung alveoli model to be mechanically actuated to mimic breathing motions. The renal proximal tubule model was used to mimic glucose reabsorption in kidney and model renal inflammation. The latter part of this work focusses on further improving this platform to increase platform robustness and to allow for incorporating supporting cells such as fibroblasts into the hydrogel matrix. This allowed us to model tubular injuries in kidney such as cisplatin induced -nephrotoxicity and TGF- β1 induced- tubulointerstitial fibrosis. Furthermore this work also describes the development of a high-throughput TEER meter that can be integrated with the AngioPlate platform allowing for rapid, non-invasive measurement of renal epithelial barrier integrity. Given that both platforms are designed in a 384-well plate format, they are high throughput and compatible with existing technologies like high-content imaging systems, robotic liquid handling systems, and microplate readers allowing for widespread adoption across diverse research settings. It is anticipated that the contributions described in this work will significantly advance our understanding of disease propagation and accelerate drug development process. / Thesis / Candidate in Philosophy / Drug development is a complex and expensive process, often hindered by a high failure rate in clinical trials. This failure is partly due to the inadequacy of current predictive models in the early stages of development. To address this, researchers are turning to innovative microphysiological systems known as Organ-on-a-Chip, which mimic organ structure and functions in the lab. However, these systems have been limited in their use due to low throughput. To overcome this limitation, microphysiological systems in multi-well formats called the IFlowPlate and AngioPlate were developed through the works outlined in this thesis. These platforms are designed to be high-throughput, scalable, user-friendly, and are compatible with existing technologies, such as microplate readers, high-content imaging systems and robotic liquid handlers, making them accessible to a wide range of researchers. By combining the physiological relevance of microphysiological systems with the high-throughput capabilities, these platforms aim to transform the way we study diseases and test drugs.

Le cancer du sein est l'une des principales causes de décès chez les femmes dans le monde. Le traitement de référence actuel est l'excision chirurgicale de la tumeur. Malgré l'intervention chirurgicale, le risque de résurgence est élevé. Pour le prévenir, l'excision chirurgicale est suivie d'un traitement chimiothérapeutique pendant plusieurs mois. La chimiothérapie est un traitement systémique qui a de nombreux effets indésirables en raison de sa non-spécificité. Ces dernières années, de nombreux traitements expérimentaux ciblés ont été proposés comme alternative. L'un d'entre eux est la thérapie photothermique utilisant des nanoparticules plasmoniques (NPs). Malheureusement, les chercheurs ne disposent pas d'une plateforme efficace pour tester les traitements expérimentaux visant à réduire le risque de résurgence. Pour résoudre ce problème, nous développons un organe sur puce (OSP) du micro-environnement tumoral après l'excision chirurgicale. L'OSP est une combinaison de microfluidique et d'ingénierie tissulaire qui peut simuler plusieurs organes. Cette technologie permet un débit élevé, une meilleure contrôlabilité et est moins coûteuse que les modèles habituels comme les animaux. Pour mener à bien ce projet, la méthodologie à suivre est divisée en quatre étapes. Premièrement, nous fabriquons une puce microfluidique pour produire des microtumeurs vascularisées. Deuxièmement, la chirurgie sera simulée en effectuant une ablation thermique sur le sphéroïde tumoral à l'intérieur de la puce. Troisièmement, la microscopie dynamique différentielle sera utilisée pour cartographier la concentration et la diffusion des NP dans les différents compartiments de la puce. Le développement ultérieur de cette nouveauté offrira la possibilité de développer des tests personnalisés et sera également adapté à d'autres types de cancer tels que le cancer du cerveau ou du foie. / Breast cancer is one of the most leading causes of death among women worldwide. The current gold standard treatment is a surgical excision of the tumour. Despite the surgery, the risk of a resurgence is high. To prevent this, surgical excision is followed by chemotherapeutic treatment for several months. Chemotherapy is a systemic treatment that has multiple adverse effects due to its non-specificity. In recent years, many targeted experimental treatments have been put forth as an alternative. One of them is photothermic therapy using plasmonic nanoparticles (NPs). Unfortunately, researchers don’t have an efficient platform to test experimental treatment aimed at mitigating the risk of a resurgence. To address this problem, we are developing an organ-on-achip (OOC) of the tumour microenvironment post-surgical excision. OOC is a combination of microfluidic and tissue engineering that can simulate several organs. This technology allows a high throughput, better controllability and is less expensive than usual models like animals. To carry out this project, the methodology to be followed is divided into four stages. First, we are fabricating a microfluidic chip to produce vascularized microtumors. Second, the surgery will be simulated by performing a thermal ablation on the tumour spheroid inside the chip. Third, the differential dynamic microscopy will be used to map the concentration and diffusion of the NPs in the different compartments of the chip. Later development of this novelty will offer the possibility of developing a personalized test and be suitable for other types of cancer such as brain or liver cancer.

<p>  </p> <p>Diabetes, a chronic condition characterized by elevated blood glucose levels, arises when pancreatic β-cells lose capacity to produce a robust, dynamic glucose-stimulated insulin secretion (GSIS) response. Accurate measurement of β-cell health and function <em>ex vivo</em> is thus fundamental to diabetes research, including studies evaluating disease mechanisms, novel drug candidates, and replacement β-cell populations. However, present-day dynamic GSIS assays typically represent end-point measurements, involve expensive commercial perifusion machines, and require time-consuming enzyme-linked immunosorbent assays (ELISA) for insulin detection. Microfluidic devices developed as accessible, low-cost alternatives still rely on secondary ELISAs and suspend islets in liquid medium, limiting their survival <em>in vitro</em>. Here, we present a novel, 3D-printed microphysiological system (MPS) designed to recreate components of <em>in-vivo</em> microenvironments through encapsulation in fibrillar type I collagen and restoration of favorable molecular transport conditions. Following computational-informed design and rapid prototyping, the MPS platform sustained collagen-encapsulated mouse islet viability and cytoarchitecture for 5 days and supported <em>in-situ</em> measurements of dynamic β-cell function. To rapidly detect insulin secretion from β-cells in the MPS, we then developed a highly sensitive electrochemical sensor for zinc (Zn2+), co-released with insulin, based on glassy carbon electrodes modified with bismuth and indium and coated with Nafion. Finally, we validated sensor detection of Zn2+ released from glucose-stimulated INS-1 β-cells and primary mouse islets, finding high correlation with insulin as measured by standard ELISA. Together, the 3D MPS and Zn2+ sensor developed in this dissertation represent novel platforms for evaluating β-cell health and function in a low-cost, user-friendly, and physiologically-relevant manner. </p>