Cell adhesion and migration on linear sti ness gradient hydrogels

LORENA SIGAUT; CATALINA VON BILDERLING; NICOLAS MUZZIO; LÍA I PIETRASANTA

San Luis

Congreso; XLVIII Reunión Anual Sociedad Argentina de Biofísica; 2019

Mechanical stimuli play a significant role in different physiological and pathological processes such as tissue and cancer development. Cells are constantly exposed to di erent external mechanical stimuli coming from the extracellular matrix and neighbor cells, which influence several cell functions like adhesion, proliferation, migration, and differentiation. These mechanical stimuli are not always homogeneous and may present spatiotemporal 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.1 to fabricate the gels on top of 25 mm diameter coverglasses. The topography and mechanical properties of the gels were assessed by an AFM- based technique: PeakForce Quantitative Nanomechanical Mapping (PFQNM2).During image acquisition, force curves were collected and analyzed along with the topography, providing the simultaneous maps of elastic modulus, deformation, and adhesion. A gradient of gel sti ness was observed with values depending on the acrylamide and bis-acrylamide solution concentrations. Cell adhesion on di erent regions of the gel was examined by Scanning Electron Microscopy and Confocal microscopy. Cell areas and morphologies were dependent on the local mechanical properties of the underlying hydrogel. Live cell imaging was performed to study cell migration patterns, which resulted to be strongly dependent on the slope of the stiffness change along the gel. These results will allow us to explore the stiffness-sensitive expression, localization and dynamics of the mechanosensitive proteins zyxin and vinculin.