A Microfluidic Device for Label-Free Sorting of Circulating Tumor Cells

This thesis presents a novel method to separate cancer cells from blood samples, demonstrating experimentally the base concept behind this technology. Cancer is one of the principal causes of death in the world. Humanity is making endless efforts to reduce cancer related mortality and over the last decades improvements has been made. However, metastatic cancer remains almost untreatable for most of patients. Metastatic cancer is an advanced stage of the disease that consists in the spreading of tumor cells all over the organism through blood vessels. Prevention and early treatment are fundamental to cure patients, since tackling the disease at his early stages it is the most secure way to avoid metastasis. New diagnosis techniques are arising every year not only to detect circulation tumor cells (CTCs) but to collect them too. These cells are further analyzed to provide more effective treatments for every specific patient. Microfluidics has a central role in the developing of these new techniques that are presented in the introduction of this thesis. The presented device combines two popular and valuable techniques, deterministic lateral displacement (DLD) to sort cells depending on their size and di-electrophoresis (DEP) to trap selectively white blood cells. In chapter 2 device theory and fabrication method are explained. In experimental section, four different DLD designs are tested with polystyrene microbeads and A549 cancer cells, varying buffers and applying electric fields with different intensity and frequency. Results and conclusions are presented at the end, proposing an outlook on future goals and challenges to face to reach the final aim of separating circulating tumor cells from blood samples drawn from patients.