The impacts of shape in lateral migration of cancer cells in a microchannel.

This work presents the development of a novel approach to model the dynamics of cancer cells in microcirculation. We investigate the role the membrane elasticity, and cancer cell shape on deformation dynamics under the shear and pressure forces in a micro-channel. The proposed numerical model is based on a hybrid continuum-particle approach. The cancer cell model includes the cell membrane, nucleus, cytoplasm and the cytoskeleton. The Dissipative Particle Dynamics method was employed to simulate the mechanical components. The blood plasma is modeled as a Newtonian incompressible fluid. A Fluid-Structure Interaction coupling, leveraging the Immersed Boundary Method is developed to simulate the cell's response to flow dynamics. We quantify how subtle variations in these biophysical properties alter deformation indices such as sphericity and aspect ratio, and stress distributions on the membrane of the cancer cell. Our findings align well with existing computational and experimental studies. Results reveal that increased membrane stiffness reduces overall deformation as well as the total distance traveled. Similarly, cell geometry strongly influences flow-structure interactions: near-spherical morphologies exhibit stable deformation with minimal sensitivity to shear variations, whereas elongated geometries show pronounced orientation and stretching effects. Collectively, these findings highlight the critical importance of cell-specific heterogeneity in governing cell dynamics in microvascular flows. Furthermore, the intracellular and extracellular dynamics response of the cancer cell are intrinsically linked to their shape, in which certain morphologies displayed strong resistance to the fluid-induced forces and the ability to migrate in various directions. The insights obtained provide a mechanistic framework for understanding circulating tumor cell transport in shear-dominated environments during metastasis. Our work may inform the design of biomimetic microfluidic systems and therapeutic strategies targeting cancer cell detection and cancer prognosis.