Design of a Micro-Separator for Circulating Tumor Cells (CTCs) from Blood Flow Using Hybrid Pinched Flow Fractionation (PFF) and Dielectrophoresis Methods

Separation of blood cells has a widespread application in medical sciences. Separation of these cells helps identifying their properties. Knowing the properties of circulating tumor cell’s (CTC) and the effect of different drugs on them can significantly help to develop and improve patient’s treatment methods. During recent years, microfluidic devices for separation and sorting of these cells have been significantly developed. There are different methods for cell sorting. In this research, the size and the electrical properties of cells have been considered as the main criteria for cell separation and by combining pinched flow fractionation (PFF) as a passive method with dielectrophoresis as an active method, the separation of MDA-435 mammalian circulating tumor cell from white and red blood cells is investigated. These cells have small size differences where in pinched flow fractionation, incapability to separate particles of similar sizes is a major challenge. In this research, dielectrophoresis force creates a gap between circulating tumor cells and white blood cells in the pinched segment and after hydrodynamic expansion in the broadened segment, circulating tumor cells, white blood cells, and red blood cells will be collected in their specific outlet branches. Results show that this hybrid method can separate tumor cells effectively.