1 research outputs found
Morphology and Adhesion Strength of Myoblast Cells on Photocurable Gelatin under Native and Non-native Micromechanical Environments
We have quantitatively determined
how the morphology and adhesion
strength of myoblast cells can be regulated by photocurable gelatin
gels, whose mechanical properties can be fine-tuned by a factor of
10<sup>3</sup> (0.1 kPa ≤ <i>E</i> ≤ 140 kPa).
The use of such gels allows for the investigation of mechanosensing
of cells not only near the natural mechanical microenvironments (<i>E</i> ∼ 10 kPa) but also far below and beyond of the
natural condition. Optical microscopy and statistical image analysis
revealed that myoblast cells sensitively adopt their morphology in
response to the substrate elasticity at <i>E</i> ∼
1–20 kPa, which can be characterized by the significant changes
in the contact area and order parameters of actin cytoskeletons. In
contrast, the cells in contact with the gels with lower elastic moduli
remained almost round, and the increase in the elasticity beyond <i>E</i> ∼ 20 kPa caused no distinct change in morphology.
In addition to the morphological analysis, the adhesion strength was
quantitatively evaluated by measuring the critical detachment pressure
with an aid of intensive pressure waves induced by picosecond laser
pulses. This noninvasive technique utilizing extremely short pressure
waves (pulse time width ∼100 ns) enables one to determine the
critical pressure for cell detachment with reliable statistics while
minimizing the artifacts arising from the inelastic deformation of
cells. The adhesion strength also exhibited a transition from weak
adhesion to strong adhesion within the same elasticity range (<i>E</i> ∼ 1–20 kPa). A clear correlation between
the cell morphology and adhesion strength suggests the coupling of
the strain of the substrate and the mechanosensors near focal adhesion
sites