A Numerical Study on Highly Viscous Compound Cancer Cell Microfiltration

Cancer is a leading cause of death worldwide. There has been extensive research on cancer in recent decades, with many studies focusing on Circulating Tumor Cells (CTCs), i.e., cancer cells shed into the circulating bloodstream from a primary tumor site. CTCs are mainly responsible for initiating metastases, and can be used as an indicator for early cancer detection. Investigating CTCs and the related detection methods such as microfiltration is of great importance. CTCs as well as other cells are normally composed of highly viscous nucleus and cytoplasm which are encapsulated by the outermost layer of cortical membrane. In order to account for the effects of viscous nucleus and cytoplasm on the microfiltration process and study the dynamic characteristics comprehensively, a realistic model is preferred. In this research, we employ the compound droplet model consisting of three layers, the layer of cell membrane, cytoplasm and nucleus, to capture the full range of CTCs behavior during the microfiltration process. The compound cell deformation and pressure signature during microfiltration are studied numerically. Also discussed are the effects of nucleus-cytoplasm ratio (N/C ratio), their viscosity as well as surface tension on the cell behavior when it squeezing through the filter channel. Our results can gain insight into the physics behind the filtering process and provide some guidance to the design and optimization of such devices.