Investigation of cell adhesion, contraction and physical restructuring on shear sensitive liquid crystals

In this study, the nature of cell attachment and contraction on the surface of a shear sensitive cholesteryl ester liquid crystal (LC) was examined. This interaction has the potential to be utilized as a novel cell force transducing assay. Preliminary studies indicated that cells cultured on the LC induce deformations in the underlying LC layer. This study aimed at determining if those deformations resulted from the weight of the cell or from forces generated within the cell being transmitted to the LC surface by focal adhesions (FA). In order to study this cell-surface relationship, the forces generated within the cell by the actin cytoskeleton were inhibited by treatment with 30 μM cytochalasin-B and cell surface attachment via integrins was broken by treatment of cells with, 0.25 Trypsin-EDTA. In the study of the morphology changes of cells and their interfacial interactions within the LC were investigated using fluorescence staining of the actin cytoskeleton and Widefield Surface Plasmon Resonance (WSPR) microscopy. Both cytochalasin-B and trypsin treatments caused deformations in the shear sensitive LC surface to decrease and disappear. This indicates that the deformations in the LC were induced by forces generated in the actin cytoskeleton being transmitted to the LC surface via FA. Fluorescent staining of the actin cytoskeleton and immunofluorescent vinculin staining indicated that cells cultured on the soft LC substrate developed a diffuse actin cytoskeleton and vinculin staining revealed FA around the periphery of the cells. These finding were confirmed by WSPR microscopy which indicated that cell surface attachments formed around the periphery of cells grown on the liquid crystals. © 2011 Springer Science+Business Media B.V.