Hui Jianan, Pang Stella W
Department of Electronic Engineering, City University of Hong Kong Hong Kong China
Center for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong Hong Kong China.
RSC Adv. 2019 Mar 14;9(15):8575-8584. doi: 10.1039/c8ra10170a. eCollection 2019 Mar 12.
Three-dimensional (3D) cell migrations are regulated by force interactions between cells and a 3D extracellular matrix (ECM). Mapping the 3D traction force generated by cells on the surrounding ECM with controlled confinement and contact area will be useful in understanding cell migration. In this study, double-sided micropost arrays were fabricated. The cell traction force was mapped by microposts on the top and bottom of opposing surfaces with a controlled separating distance to create different confinements. The density of micropost arrays was modified to investigate the effect of cell contact area on 3D traction force development. Using MC3T3-E1 osteoblastic cells, the leading traction force was found to increase with additional contact surface on the top. Summing force vectors on both surfaces, a large force imbalance was found from the leading to trailing regions for fast migrating cells. With 10 μm separation and densely arranged microposts, the traction force on the top surface was the largest at 28.6 ± 2.5 nN with the highest migration speed of 0.61 ± 0.07 μm min. Decreasing the density of the top micropost arrays resulted in a reduced traction force on the top and lower migration speed. With 15 μm separation, the cell traction force on the top and migration speed further decreased simultaneously. These results revealed traction force development on 3D ECM with varied degrees of confinement and contact area, which is important in regulating 3D cell migration.
三维（3D）细胞迁移受细胞与三维细胞外基质（ECM）之间的力相互作用调节。绘制细胞在具有可控限制和接触面积的周围ECM上产生的三维牵引力，将有助于理解细胞迁移。在本研究中，制作了双面微柱阵列。通过在相对表面的顶部和底部设置微柱来绘制细胞牵引力，微柱之间具有可控的分离距离以创建不同的限制条件。改变微柱阵列的密度，以研究细胞接触面积对三维牵引力发展的影响。使用MC3T3-E1成骨细胞，发现随着顶部额外接触面积的增加，主要牵引力会增大。对两个表面的力矢量求和，发现快速迁移细胞从前导区域到尾随区域存在较大的力不平衡。当分离距离为10μm且微柱密集排列时，顶表面的牵引力最大，为28.6±2.5 nN，最高迁移速度为0.61±0.07μm/min。降低顶部微柱阵列的密度会导致顶表面的牵引力降低以及迁移速度下降。当分离距离为15μm时，细胞在顶表面的牵引力和迁移速度同时进一步降低。这些结果揭示了在具有不同程度限制和接触面积的三维ECM上牵引力的发展情况，这对调节三维细胞迁移很重要。
