Zhang Guocheng, Chang Yufang, Fan Na, Yan Bin, Li Xianmeng, Yang Zihan, Yu Zhenyang
Department of Mechanical Engineering, Anyang Institute of Technology, Yellow River Avenue West, Anyang 455000, China.
School of Accountancy, Anyang Institute of Technology, Yellow River Avenue West, Anyang 455000, China.
Micromachines (Basel). 2023 Feb 5;14(2):397. doi: 10.3390/mi14020397.
In recent years, atomic force microscopes have been used for cell transfection because of their high-precision micro-indentation mode; however, the insertion efficiency of the tip of AFM into cells is extremely low. In this study, NIH3T3 mouse fibroblast cells cultured on a flexible dish with micro-groove patterns were subjected to various substrate strains at 5%, 10%, 15%, and 20%. It was found that the cell stiffness depends on the prestress of the cell membrane, and that the insertion rate of AFM tips into the cell membrane is proportional to the stiffness through the AFM indentation experiment. The finite element analysis proves that prestress increases the bending stiffness of the cytoskeleton, allowing it to better support the cell membrane, which realizes the stress concentration in the contact area between the AFM tip and the cell membrane. The results indicate that the prestress contributes to the mechanical properties of the cell and suggest that the insertion efficiency could be greatly improved with an increase of the prestress of the cell membrane.
近年来，原子力显微镜因其高精度微压痕模式而被用于细胞转染；然而，原子力显微镜探针插入细胞的效率极低。在本研究中，将培养在具有微槽图案的柔性培养皿上的NIH3T3小鼠成纤维细胞置于5%、10%、15%和20%的各种底物应变下。通过原子力显微镜压痕实验发现，细胞硬度取决于细胞膜的预应力，且原子力显微镜探针插入细胞膜的速率与硬度成正比。有限元分析证明，预应力增加了细胞骨架的弯曲刚度，使其能够更好地支撑细胞膜，从而实现了原子力显微镜探针与细胞膜接触区域的应力集中。结果表明，预应力有助于细胞的力学性能，并表明随着细胞膜预应力的增加，插入效率可大大提高。
