Studying Intercellular Signaling Underlying Human Diseases Using Open Microfluidic Coculture

Abstract

This dissertation focuses on the development of innovative open microfluidic cell culture platforms and their application in studying intercellular signaling underlying human diseases in controlled ex vivo microenvironments. Chapter 1 introduces the background of open microfluidic capillary systems, including the design considerations and current fabrication techniques, and addresses the advantages of using open microfluidic cell culture systems to study intercellular signaling. Chapter 2 presents a new open microfluidic capillary platform, which patterns biocompatible hydrogel walls along a rail insert set inside established cultureware. The permeable hydrogel walls provide segregation for the cells and support diffusion of soluble factors. Chapter 3 discusses a microscale collagen gel contraction assay with an engineered well plate insert that uses surface tension forces to load and manipulate small volumes of cell-laden collagen. The system is easily operated with two pipetting steps and the microscale device moves dynamically as a result of cellular forces. Chapter 4 presents an open microfluidic coculture platform consisting of two independent cell culture regions separated by a half wall. The cell types are selectively seeded into the regions and connected with cell culture media. Using the device, we show that human kidney tubular epithelial cells can tune organ-specificity in other endothelial cell types. Chapter 5 shows a preliminary asthma disease coculture model of human lung fibroblasts and primary alveolar macrophages using a similar open microfluidic coculture device to that described in Chapter 4. The preliminary cell culture result indicates that lung fibroblasts exhibit elevated cell contractility when cultured separately with alveolar macrophages in shared cell culture media. Chapter 6 concludes the thesis and proposes some future research directions and interesting metabolomic studies using existing or alternative open microfluidic systems.