(674e) Straining Red Blood Cells with Liquid Crystals

The response of biological cells to applied stress is central to the functioning of living systems, and dysfunction is often characterized by change in biomechanical response. Changes in the mechanical properties of red blood cells (RBCs), for example, are associated with Sickle cell disease and Malaria, but facile methods to characterize mechanical properties of cells do not exist. Liquid crystals (LCs), because of their long-range molecular ordering, can impart anisometric elastic stresses and alter the shapes of soft colloids, such as phospholipid vesicles, in turn influencing their physical properties. Here, we show that the elasticity of LCs can strain healthy RBCs and that the elastic strain shared between the LC and the RBC can be modulated as a function of temperature. Consistent with the temperature-dependent elastic properties of the LC phases, we observe the RBCs to transform from characteristic biconcave shapes to spindle shapes with asphericity ξ as high as ~ 3. Further, we use vapor pressure osmometry to show that it is possible to prepare lyotropic LCs that are in osmotic equilibrium with the interior of RBCs and that, under these conditions, the elasticity of the LCs generate mechanical stresses that are sufficiently large to drive reversible changes in cell shape. Additionally, we show that changes in mechanical properties of the RBCs, achieved here by cross-linking with glutaraldehyde, can be transduced by the shape-response of the RBC to LC elasticity. Overall, these results provide insight into the coupling of strain in biological soft materials with LCs and form the basis for simple diagnostic tools to rapidly identify the health of cells.