Cell Viscoelasticity Measurements by Flow Cytometry in Microfluidic Channels

Structural and mechanical alterations in cells are related to their state, functions, and certain diseases, including cancer. Techniques such as atomic force microscopy, magnetic twisting, micropipette aspiration, among others, allow the study of cell rheology at the cost of technically demanding and time-consuming procedures. Approaches using microfluidics significantly expand the possibilities for measurements due to their adaptability in design and ability to obtain individual cellular characteristics, with greater speed and volume of data acquisition when compared to other techniques.

In this work, our goal is to study the rheology of cells and their response to drug treatments. Using 3D printing and PDMS (Polydimethylsiloxane), we created microfluidic devices that will be employed to study viscoelastic parameters. The device consists of a rectangular channel measuring 200×200 µm and 45 mm in length, through which cells are deformed by a constant flow. With the aid of a microscope, images obtained by a high-frame-rate camera, image processing techniques, and deep learning, we are able to extract morphological features and correlate them with viscoelastic parameters such as loss modulus, storage modulus, stiffness, and fluidity.