Department of Mechanical and Biomedical Engineering, City University of Hong Kong , Hong Kong.
City University of Hong Kong, Shenzhen Research Institute , Shenzhen, China.
Langmuir. 2018 Jan 30;34(4):1750-1759. doi: 10.1021/acs.langmuir.7b02935. Epub 2018 Jan 18.
Microcontact printing (μCP) is widely used to create patterns of biomolecules essential for studies of cell mechanics, migration, and tissue engineering. However, different types of μCPs may create micropatterns with varied protein-substrate adhesion, which may change cell behaviors and pose uncertainty in result interpretation. Here, we characterize two μCP methods for coating extracellular matrix (ECM) proteins (stamp-off and covalent bond) and demonstrate for the first time the important role of protein-substrate adhesion in determining cell behavior. We found that, as compared to cells with weaker traction force (e.g., endothelial cells), cells with strong traction force (e.g., vascular smooth muscle cells) may delaminate the ECM patterns, which reduced cell viability as a result. Importantly, such ECM delamination was observed on patterns by stamp-off but not on the patterns by covalent bonds. Further comparisons of the displacement of the ECM patterns between the normal VSMCs and the force-reduced VSMCs suggested that the cell traction force plays an essential role in this ECM delamination. Together, our results indicated that μCPs with insufficient adhesion may lead to ECM delamination and cause cell death, providing new insight for micropatterning in cell-biomaterial interaction on biointerfaces.
微接触印刷（μCP）被广泛用于创建对细胞力学、迁移和组织工程研究至关重要的生物分子图案。然而，不同类型的μCP 可能会产生具有不同蛋白质-基底附着力的微图案，这可能会改变细胞行为并对结果解释造成不确定性。在这里，我们对两种用于涂覆细胞外基质（ECM）蛋白的 μCP 方法进行了表征（盖印和共价键），并首次证明了蛋白质-基底附着力在决定细胞行为方面的重要作用。我们发现，与牵引力较弱的细胞（例如内皮细胞）相比，牵引力较强的细胞（例如血管平滑肌细胞）可能会使 ECM 图案分层，从而导致细胞活力降低。重要的是，这种 ECM 分层仅在盖印图案上观察到，而在共价键图案上则没有观察到。进一步比较正常 VSMCs 和力降低的 VSMCs 之间 ECM 图案的位移表明，细胞牵引力在这种 ECM 分层中起着重要作用。总之，我们的结果表明，附着力不足的 μCP 可能导致 ECM 分层并导致细胞死亡，为生物界面上细胞-生物材料相互作用的微图案化提供了新的见解。
