Measuring cell deformation by microfluidics

Abstract

Microfluidics is an increasingly popular method for studying cell deformation, with various applications in fields such as cell biology, biophysics, and medical research. Characterizing cell deformation offers insights into fundamental cell processes, such as migration, division, and signaling. This review summarizes recent advances in microfluidic techniques for measuring cellular deformation, including the different types of microfluidic devices and methods used to induce cell deformation. Recent applications of microfluidics-based approaches for studying cell deformation are highlighted. Compared to traditional methods, microfluidic chips can control the direction and velocity of cell flow by establishing microfluidic channels and microcolumn arrays, enabling the measurement of cell shape changes. Overall, microfluidics-based approaches provide a powerful platform for studying cell deformation. It is expected that future developments will lead to more intelligent and diverse microfluidic chips, further promoting the application of microfluidics-based methods in biomedical research, providing more effective tools for disease diagnosis, drug screening, and treatment.

Keywords: cell deformation; cell imaging; cell mechanical characterization; high-throughput analysis; microfluidics.

FIGURE 1

Schematic diagram of different micro-scale structures used for measuring cell deformation in cellular rheology methods. The direct contact between cells and microchannels under the influence of fluid shear stress leads to the deformation of individual suspended cells (A–D). The target cell is located in the converging streamline at the center of the flow, without direct contact with the microstructure, resulting in the deformation of individual suspended cells (E, F). (Created with BioRender.com).

FIGURE 2

Schematic diagram of the deformation induced in individual cells using the optical stretch deformation cytometer. The optical stretcher captures cells in suspension within an optical trap and stretches them in situ. Cells transition from a stretched state to a relaxed state within a rectangular region, changing their shape from elliptical to circular. The solid box represents the region where cell stretching and relaxation occur, and is used to calculate deformation parameters for red blood cells under flow. (Created with BioRender.com).

FIGURE 3

Schematic diagram of the Real-time deformability cytometry. The undeformed cells enter the narrow microfluidic channel in an elliptical shape and undergo deformation under the influence of pressure gradients and shear stress. The cells are captured by a high-speed camera at the end of the channel for real-time identification and analysis of the cells as well as contour measurement using data analysis software. (Created with BioRender.com).

FIGURE 4

Study of red blood cells flow and deformation in capillaries based on a single-channel microfluidic device. (A–D) show the deformation of red blood cells when they are in different areas of the capillaries. No morphological changes occurred when the cells approached and reached the capillary entrance. When entering the capillaries, the cells undergo a large morphological change. After passing through the capillaries, the cells return to their natural state. (Created with BioRender.com).

FIGURE 5

Flow of malaria-infected erythrocytes within capillaries of different sizes in a single-channel microfluidic device and blockage behavior. The widths of the capillaries from left to right are 8, 6, 4, and 2 μm. Arrows indicate the direction of cell flow. (A1–A4) indicates that the cyclosomal erythrocytes at the early stage of infection can pass through the capillaries smoothly; (B1–B2) represents that the erythrocytes at the end of infection can only pass through the 8 and 6 μm capillaries, and (B3–B4) represents that the erythrocytes at the end of infection cannot pass through the capillaries and cause blockage of the microchannels. (C1) Indicates that the erythrocytes at the Schizont stage can only pass through capillaries of 8 μm but not capillaries of 6 μm and below (C2–C4) (Created with BioRender.com).

FIGURE 6

Schematic diagram of the multi-channel microfluidic device. The microfluidic channel contains several side-by-side arrays of microtubules with a width of only 3 μm, which deform the red blood cells as they flow through the arrays (Created with BioRender.com).

FIGURE 7

Schematic of an open-channel microfluidic device for studying the cell deformation during migration in a confined environment. The dashed line indicates the area that is perforated to provide open access (Created with BioRender.com).