Contact-mediated cell migration strongly determines the invasiveness of the corresponding cells, collective migration, and morphogenesis. The quantitative study of cellular response upon contact relies on cell-to-cell collision, which rarely occurs in conventional cell culture. Herein, we developed a strategy to activate a robust cell-to-cell collision within smooth muscle cell pairs. Nanomechanical traction force mapping reveals that the collision process is promoted by the oscillatory modulations between contraction and relaxation and orientated by the filopodial bridge composed of nanosized contractile machinery. This strategy can enhance the occurrence of cell-to-cell collision, which renders it advantageous over traditional methods that utilize micropatterned coating to confine cell pairs. Furthermore, modulation of the balance between cell tugging force and traction force can determine the repolarization of cells and thus the direction of cell migration. Overall, our approach could help to reveal the mechanistic contribution in cell motility and provide insights in tissue engineering.

中文翻译：

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收缩和松弛之间振荡的受限细胞间碰撞的纳米机械力映射。

接触介导的细胞迁移强烈决定了相应细胞的侵袭性，集体迁移和形态发生。接触后细胞反应的定量研究依赖于细胞间的碰撞，这在常规细胞培养中很少发生。在本文中，我们开发了一种策略来激活平滑肌细胞对内的牢固的细胞间碰撞。纳米机械牵引力映射显示，碰撞过程是由收缩和松弛之间的振荡调制促进的，并且由由纳米级收缩机械组成的丝状桥定向的。这种策略可以增强细胞间碰撞的发生，从而使其优于使用微图案涂层限制细胞对的传统方法。此外，细胞拉力和牵引力之间平衡的调节可以决定细胞的复极化，从而决定细胞迁移的方向。总体而言，我们的方法可以帮助揭示机械运动对细胞运动的贡献，并提供有关组织工程学的见解。