Biophysical Society Thematic Meeting | Singapore

Mechanobiology of Disease

Poster Abstracts

60-POS Board 60 Nanoscale Studies of Cell Mechanics with Atomic Force Microscopy

Wanxin Sun 1 , Bede Pittenger 1 , Andrea Slade 1 , Manfred Radmacher 2 , Peter Dewolf 1 . 1 Bruker Nano Surfaces, Santa Barbara, CA, USA, 2 Universität Bremen, Breman, Germany. Cell biology has seen a surge in mechanobiology-related research directed towards understanding how cells exert and respond to forces. Examining the effects of these forces has a wide-range of applications from understanding disease pathology to tissue engineering. Atomic force microscopy (AFM) not only allows direct examination of the nanoscale structure of cell membrane surfaces, it also provides unique opportunities to measure the nanomechanical properties of cells. In this study we used a combination of AFM force spectroscopy-based modes to investigate both the elastic and viscoelastic behavior of living cells. Using PeakForce QNM mode, we were able to map the modulus across individual mammalian cells. These 2D spatial maps provide both high-resolution and quantitative measurements of cell elasticity. In other PeakForce QNM studies, we successfully detected modulus variations that occur during division of E. coli cells. By integrating PeakForce QNM with fluorescence microscopy we were also able to demonstrate a correlation between changes in elasticity and bacteria viability. However, to fully understand cell mechanics, one must also consider cell response over a wide range of timescales. We used advanced AFM force spectroscopy to examine the creep response of living cells. Through integration with fluorescence microscopy, we also attempted to correlate variations in these properties to subcellular structures with nanoscale resolution. With regards to studying dynamic processes involved with cell mechanics, traditional AFM has been restricted due to the relatively longer image acquisition times. With recent advances in high-speed AFM, we have begun to apply a unique combination of high-resolution and high-speed AFM imaging to investigate the mechanics of cell migration. We were able to directly observe the formation and advancement of individual lamellipodia and fillipodia on living stem cells, as well as reorganization events within the actin cytoskeleton during migration.

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