Development of microfluidic platforms for therapeutic purposes

Abstract

This thesis describes the present state of the development and applications of microfluidic systems used in cell biology and analyses of experiments conducted with in house fabricated thermoplastic based microfluidic devices. COP based microbioreactors are produced by hot embossing and thermocompression bonding methods. Yeast and mammalian (THP-1) cells are employed in microfluidic experiments where RFP:Nop56 protein is used to track changes in cell cycle as well as protein synthesis within the yeast cells and GFP:ASC gene with a role in apoptosis is used to track the drug effects on THP-1 cells. HU, metformin, temsirolimus and HMF are administered to yeast cells and their response to these drugs are investigated. By computational systems biology approach, a genome-scale metabolic model specific to the yeast is reconstructed, and the inhibitory effect of HMF on growth and ethanol production is elaborated by estimating the internal flux distribution within the yeast metabolic network. To develop putative treatment strategies towards cancer, the COP based microbioreactor is integrated with Cr/Au interdigitated electrodes to test TTFields. In the high electrical field experiment, the yeast cells go through electroporation and in the low electrical field experiment, the cells have prolonged mitosis. Furthermore, human monocytic leukemia cell line THP-1 cells are tested in two-phase microfluidic devices, where cells are confined to droplets with several inhibitors/drugs. An increase in the fluorescence intensity of the ASC gene responsible for apoptosis is observed in cells under the influence of drugs. An important conclusion of this thesis is that these microfluidic platforms can be successfully used for studying the drug effects on tumors, observe cell to cell heterogeneity and may shed light on the putative treatment strategies towards cancer. These microbioreactors are still open for research and development, and solutions need to be found for each case separately.