| Cell-substratum interactions are important in the study of certain disease states, such as cancer growth/metastasis and cardiovascular disease, and in the development of biosynthetic materials. The transduction of signals between an adherent cell and the extracellular matrix (ECM) results in changes to various cell parameters, including cell spreading and morphology. However, changes to the mechanical properties of the cell membrane due to adhesion to a substratum have not been studied.;In order to study the cellular mechanism of membrane sensitivity to fluid shear, a surface that induces 100% cell death was desired. A surface made from 0.2% lanolin (w/vol), a wool wax, was found to produce 100% NBT II cell death after fluid shear. Further investigation of this surface showed that cell interaction with specific fatty acids (FA) and FA esters of lanolin resulted in membrane rupture. Using a surface made from an ethanol extract of lanolin (0.2% LanEx), the role of the cytoskeleton on membrane stability was studied. For the first time, it was found that the organization of actin stress fibers in NBT II cells grown on a 0.2% LanEx surface is significantly different from a glass surface (- control), and contributes to the mechanical instability of cell membranes.;Polystyrene (PS), the most commonly used surface for tissue culture, shows heterogeneity in terms of cell-substratum interaction (Tchao, 1996). On certain areas of PS, NBT II cells adhere and grow; however, when a small fluid shear force is applied over the cell surface, the apical membrane ruptures resulting in cell death. These areas of PS showed birefringence and lipophilicity. Using PS discs made from pure, atactic polystyrene, NBT II cells responded differentially to the surface arrangement of polymer molecules. |
