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Mechanobiology of Disease
Poster Abstracts
119
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.