Mechanical characterization of living and dead undifferentiated human adipose-derived stem cells by using atomic force microscopy.

In this article, to map the mechanical properties of undifferentiated human adipose-derived stem cells, local mechanical characterization is carried out on the adipose-derived stem cells. In addition, to distinguish the living and dead human adipose-derived stem cells, mechanical characterization is also implemented on both living and dead adipose-derived stem cells. In this study, Young's modulus of the cell membrane is used for representing the mechanical properties of cells. To obtain Young's modulus of cell membrane, the force-spectroscopy mode of atomic force microscopy is employed to measure the atomic force microscopy tip indentation depth and force on the cells. Then, Young's modulus is obtained through fitting these experimental data to the Hertzian contact mechanics model. The global Young's moduli of living and dead undifferentiated adipose-derived stem cells are about 1.27 and 18.61 kPa, respectively. This displays obvious gap of Young's modulus between the living and dead undifferentiated adipose-derived stem cells. Finally, comparison of the local Young's modulus shows deviation of the local Young's modulus for either living or dead undifferentiated adipose-derived stem cells, and the root-mean-square errors of the global Young's modulus of living and dead undifferentiated adipose-derived stem cells are about 0.48 and 5.05 kPa, respectively.