Abstract
Microfluidics is a promising technology for improving biology and medicine research. Artificial kidney is a microfluidic device that replaces kidney filtration function by minimizing the whole dialysis system, consist of a filtration membrane placed inside a device prepared from biocompatible materials. Bioartificial kidneys provide an extension to conventional artificial kidneys, by incorporating tissue engineering with living cellular and tissue, in an order to better mimic normal kidneys. Hydrogels are three-dimensional, hydrophilic, polymeric networks capable of absorbing large amounts of biological fluids. Due to their high water content, porosity and soft consistency, hydrogels closely simulate natural living tissue, and are widely used as an extracellular matrix. The use of porous hydrogels as ECM in microfluidic devices provides a soft and controllable mechanical properties of the matrix, improve the cell-cell and cell-ECM interaction and enables the embedding of cells, as oxygen and nutrients are able to diffuse through their structure and provide the proper environment for cell culture. The hydrolyzed polyacrylamide hydrogel was chosen for tissue engineering due to its mechanical properties, its easy shaping and its viscoelasticity. The thesis aim was to develop a Polyacrylamide hydrogel used as a filtration membrane is microfluidics forming a “filtration unit” in order to block the passage of molecule above a specific size due to their controllable mesh size. Macroporous Polyacrylamide hydrogel is prepared using emulsion technique, and used as extracellular matrix for podocytes spheroids formation. Controlling the hydrogel structural and mechanical properties leads to different responses of podocytes spheroids. Macroporous Polyacrylamide hydrogel holding podocytes spheroids will be used as filtration basement membrane encapsulated in a microfluidic device forming another “filtration unit”. The assembly of different filtration units encapsulating hydrogels seeded with podocytes cells or not, working in parallel forming the bioartificial kidney that replace the normal kidney function.