Zhang, Xinyu

Student Projects

- Investigating cell mechanics with FluidFM force spectroscopy

The mechanical properties and behavior of living cells are intimately related to the cell function. Cell stiffness and cell adhesion are the two most crucial parameters reflecting the state of cells. To quantify them, numerous methods have emerged. Traditional AFM-based single-cell force spectroscopy (SCFS) is based on attaching a living cell to the AFM cantilever via complex chemical functionalization. With the use of FluidFM, single living cells can be physically immobilized at the cantilever aperture in a straightforward way by applying an adequate negative pressure in the fluidic channel of the FluidFM probe, allowing the SCFS measurements in native conditions (without chemical treatment on cells). Besides, standard functionalized AFM cantilevers can be used only once, whilst in case of FluidFM cells can be immediately detached with a pulse of positive pressure and reused increasing the throughput and efficiency of SCFS assays.

Upon having optimized the protocol with mammalian cells, we are now collaborating with a few groups addressing biological questions as well as coupling the FluidFM with optical tools.

- 4D force map of Cardiomyocytes contractility

Cardiomyocytes (CMs) contraction is a fascinating biochemical reaction of the cells transforming the flux of ions into the mechanical contraction. This process represents the physiological state of cells and highly relates to the fundamental of cardiac diseases. Therefore, quantifying the contractile forces becomes critical in pursuance of understanding and characterizing the cardiomyocytes contraction. In this project, we aim to investigate the mechano-electrical coupling of hPSC-CMs (human pluripotent stem cell-derived cardiomyocytes) and isolated mice cardiomyocytes. Combining FluidFM and TFM (Traction Force Microscopy) we can realize a time resolved force map of the cardiomyocytes contraction with nano Newton sensitivity in both basal and vertical direction. In the meantime, FluidFM could mechanically or electrically apply stimulations. After having realized the simultaneous recording of xyz contraction forces, we are entering the stage of focusing on answering meaning biological quesiton. In this project, the student will learn about various techniques, FluidFM, Cardiomyocyte, and Electric Field Stimulation. Also the student will be exposed to biological side of the project, such as Primary Cardiomyocyte and hPSC-CMs culture. And finally the student will be able to analyze statistical data to draw meaningful conclusions.