Enhancing stiffness-based cell sorting using power-law fluids in ridged microchannels

Sorting biological cells in heterogeneous cell populations is a critical task required in a variety of biomedical applications and therapeutics. Microfluidic methods are a promising pathway toward establishing label-free sorting based on cell intrinsic biophysical properties, such as cell size and compliance. Experiments and numerical studies show that microchannels decorated with diagonal ridges can be used to separate cell by stiffness in a Newtonian fluid. Here, we use computational modeling to probe stiffness-based cell sorting in ridged microchannels with a power-law shear thinning fluid. We consider compliant cells with a range of elasticities and examine the effects of ridge geometry on cell trajectories in microchannel with shear thinning fluid. The results reveal that shear thinning fluids can significantly enhance the resolution of stiffness-based cell sorting compared to Newtonian fluids. We explain the mechanism leading to the enhanced sorting in terms of hydrodynamic forces acting on cells during their interactions with the microchannel ridges.

Automated summary

Sorting biological cells in heterogeneous cell populations is essential for various biomedical applications and therapeutics. Microfluidic methods, specifically those utilizing ridged microchannels, are a promising approach for label-free cell sorting based on biophysical properties. In this study, we use computational modeling to investigate cell sorting based on cell stiffness in ridged microchannels with shear thinning fluid. Our results demonstrate that shear thinning fluids can significantly improve the resolution of stiffness-based cell sorting compared to Newtonian fluids, and this enhancement is explained by analyzing hydrodynamic forces acting on cells during interactions with the microchannel ridges.