Fabrication and characterization of a microfluidic device for 3D cells analysis

The study of cells chemotaxis and angiogenesis phenomena plays a significant role in a better understanding of cancer evolution. As a matter of fact, cells are influenced by the physiological environment, which contains all the substances that could influence their regular life. The importance of the study of the impact nutrients or toxic elements may have is generally accepted. In fact, in the last decade a large number of studies were carried on simple 2D devices. However, this type of platform did not allow a well-simulated physiological behavior, and they were soon replaced with the study of 3D platforms. This thesis reports the fabrication, simulation and testing of a 3D microfluidic circuit to study cells chemotaxis in a platform where reagents concentration is controlled spatially and temporally. In the first part of the thesis all the technologies and processes used for the device manufacturing are listed and explained (Chapter 1). Then, an overview of the biological and physics phenomena that occur during the device usage is reported (Chapter 2). The main part of the work is focused on the experimental fabrication processes (Chapter 3) and simulations and tests for the correct device behavior (Chapter 4). In these sections, all the steps and alternatives in the fabrication process are explained, coming to the final correct device production with PDMS casting in situ process with a SU8 photoresist mold; afterward, all the simulations and tests are reported in order to analyze the device: the static and dynamic regimes are analyzed and tested, from the fluorescence method (in order to check if the gradient is correctly maintained) to some biological tests for the cells growth. Finally, conclusions and future perspectives are reported (Chapter 5).