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Mechanobiology of Disease
Poster Abstracts
120
63-POS
Board 63
Atomic Force Microscopy as Tool to Selectively Investigate the Mehcanical Properties of
Different Components of Cytoskeleton in Muscle Fibres in Vitro
Roberto Raiteri
1
, Mariateresa Tedesco
1
, Ilaria Pulsoni
1
, Christopher Ward
2
.
1
University of Genova, Genova, Italy,
2
University of Maryland, School of Medicine, Baltimore,
MD, USA.
Atomic force microscopy (AFM) allows to measure the transversal stiffness of the sub-
sarcolemma region of cells with sub-micrometer lateral and vertical resolution. By AFM
nanoindentation measurements we investigated the changes in stiffness of isolated skeletal
muscle fibres induced by acute doses of different substances capable to selectively induce
changes in the organization of microtubules and intermediate filaments, namely colchicine, taxol,
parthenolide, and Withaferin A. Our results confirm that AFM nanoindentation performed at
different penetration depths allows to selectively and quantitatively probe the response of
different regions of the sarcolemma localized in the first few hundreds of nanometers below the
sarcolemma. Such capability represents a powerful tool, complementary to other in vitro and in
vivo techniques, to investigate the mechano-transduction at the basis of generation and
progression muscle pathologies such as dystrophies.
66-POS
Board 66
Nanoscale Optomechanical Actuators for Controlling Mechanotransduction in Living Cells
Khalid Salaita
1,2
, Zheng Liu
1
,
Victor Ma
1
.
1
Emory University, Atlanta, GA, USA,
2
Emory University and Georgia Institute of Technology,
Atlanta, GA, USA.
Optical approaches for the controlling biological systems are transforming the field of cell
biology, as exemplified by caged or photoswitchable molecules and by optogenetic constructs.
Similarly, methods to harness light for delivering precise physical inputs to biological systems
could potentially transform the study of mechanotransduction. Toward this goal, I will describe
our efforts aimed at developing optomechanical actuator nanoparticles to manipulate receptor
mechanics with high spatiotemporal resolution using near-infrared illumination (Nature Methods
2016). Nanoparticles are comprised of a gold nanorod coated with a thermoresponsive polymer
shell. Illumination leads to local heating, and particle collapse, thus delivering piconewton forces
to specific cell surface receptors with high spatial (~micron scale) and temporal resolution (msec
timescales). Optomechanical actuators were used to exert forces through the integrin receptors,
thus mechanically controlling focal adhesion formation, cell protrusion, and cell migration in
living cells. This new approach to controlling mechanotransduction circuits allows for optically
controlling cell migration without the use of genetic engineering.