Cell adhesion and migration on linear stiffness gradient hydrogels

MUZZIO, NICOLÁS E.; VON BILDERLING, CATALINA; SIGAUT, LORENA; PIETRASANTA, LÍA I.

San Luis

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Biofísica; 2019

SAB

Mechanical stimuli play a significant role in different physiological and pathologicalprocesses such as tissue and cancer development. Cells are constantly exposed todifferent external mechanical stimuli coming from the extracellular matrix and neighborcells, which influence several cell functions like adhesion, proliferation, migration, anddifferentiation. These mechanical stimuli are not always homogeneous and may presentspatiotemporal heterogeneities.In the present study, we examine the results of cell adhesion and migration onpolyacrylamide hydrogels with linear stiffness gradients. We adapted the methoddeveloped by Hadden et al.1to fabricate the gels on top of 25 mm diameter coverglasses. The topography and mechanical properties of the gels were assessed by anAFM- based technique: PeakForce Quantitative Nanomechanical Mapping (PFQNM2).During image acquisition, force curves were collected and analyzed along with thetopography, providing the simultaneous maps of elastic modulus, deformation, andadhesion. A gradient of gel stiffness was observed with values depending on theacrylamide and bis-acrylamide solution concentrations. Cell adhesion on differentregions of the gel was examined by Scanning Electron Microscopy and Confocalmicroscopy. Cell areas and morphologies were dependent on the local mechanicalproperties of the underlying hydrogel. Live cell imaging was performed to study cellmigration patterns, which resulted to be strongly dependent on the slope of the stiffnesschange along the gel. These results will allow us to explore the stiffness-sensitiveexpression, localization and dynamics of the mechanosensitive proteins zyxin andvinculin.