Mammalian cells are soft, and correct functioning requires that cells undergo dynamic shape changes in vivo. Although a range of diseases are associated with stiffening of red blood cells (RBCs; e.g., sickle cell anemia or malaria), the mechanical properties and thus shape responses of cells to complex viscoelastic environments are poorly understood. We use vapor pressure measurements to identify aqueous liquid crystals (LCs) that are in osmotic equilibrium with RBCs and explore mechanical coupling between RBCs and LCs. When transferred from an isotropic aqueous phase into a LC, RBCs exhibit complex yet reversible shape transformations, from initially biconcave disks to elongated and folded geometries with noncircular cross-sections. Importantly, whereas the shapes of RBCs are similar in isotropic fluids, when strained by LC, a large variance in shape response is measured, thus unmasking cell-to-cell variation in mechanical properties. Numerical modeling of LC and cell mechanics reveals that RBC shape responses occur at constant cell membrane area but with membrane shear moduli that vary between cells from 2 to 16 × 10⁻⁶ N/m. Temperature-dependent LC elasticity permits continuous tuning of RBC strains, and chemical cross-linking of RBCs, a model for diseased cells, leads to striking changes in shape responses of the RBCs. Overall, these results provide insight into the coupling of strain between soft mammalian cells and synthetic LCs, and hint at new methods for rapidly characterizing mechanical properties of single mammalian cells in a population and thus cell-to-cell variance.

哺乳动物细胞是柔软的，正确的功能要求细胞在体内经历动态的形状变化。尽管一系列疾病与红细胞的硬化（RBC；例如，镰状细胞性贫血或疟疾）有关，但人们对机械特性以及因此对复杂粘弹性环境的形状响应的了解却很少。我们使用蒸气压测量来确定与RBC处于渗透平衡的水性液晶（LC），并探索RBC和LC之间的机械耦合。当从各向同性的水相转移到LC中时，RBC表现出复杂但可逆的形状转换，从最初的双凹面盘到具有非圆形横截面的细长和折叠几何形状。重要的是，尽管在各向同性流体中RBC的形状相似，但当受到LC过滤时，测量到形状响应的较大差异，从而揭示了机械性能在细胞之间的变化。LC和细胞力学的数值模型表明，RBC形状反应发生在恒定的细胞膜面积上，但细胞间的膜剪切模量在2到16×10之间变化^-6 N / m。温度相关的LC弹性允许连续调节RBC菌株，而RBC的化学交联（一种用于患病细胞的模型）会导致RBC形状响应的惊人变化。总体而言，这些结果提供了对哺乳动物软细胞和合成LC之间的应变耦合的见解，并暗示了快速表征种群中单个哺乳动物细胞的机械特性并由此表征细胞间差异的新方法。