Dynamic Substrate Based on Photocleavable Poly(ethylene glycol): Zeta Potential Determines Capability of Geometrical Cell Confinement
Dynamic Substrate Based on Photocleavable Poly(ethylene glycol): Zeta Potential Determines Capability of Geometrical Cell Confinement
复制标题
基于光可裂解聚乙二醇的动态基质：Zeta 电位决定几何细胞限制的能力
DOI：
10.1021/la304569e
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发表时间：
2013
期刊：
影响因子：
3.9
通讯作者：
and J. Nakanishi
中科院分区：
文献类型：
--
作者：
S. Kaneko;K. Yamaguchi;and J. Nakanishi
动态基板，其细胞周期响应于外部刺激而改变，不仅可用于以各种几何形状图案化细胞，而且可用于诱导细胞迁移或排列异型细胞。这种应用的要求是高切换效率的小区切换和长期持久的创建蜂窝模式。在本研究中，我们制备了含有光可裂解聚乙二醇（PEG）的动态基底，并考察了表面PEG密度和阳离子基底材料的电荷对上述关键要求的影响。将具有一定氨基密度和电荷的氨基封端的底物用可光裂解的PEG 5 K官能化，随后进行和不进行可光裂解的PEG 2K的交联。PEG链使表面不具有细胞粘附性，但随后对基底进行近紫外照射诱导PEG的光裂解，最终使表面具有细胞粘附性。通过原子力显微镜、接触角测量、椭圆偏振法和zeta电位测量，并辅以蛋白质吸附观察来分析基板。虽然氨基的密度在基础材料中的影响的接枝效率的PEG和电动势主要在积极的范围内，后者主要决定了蛋白质和细胞的排斥能力的基板。此外，不同的表面组合物几乎没有影响的转换效率在培养的早期阶段，但它变得更加显着培养细胞后较长的时间;细胞污染的非辐照聚乙二醇化的区域较早的表面上具有较高的正zeta电位。这些结果表明，zeta电位是光活化底物上细胞图案长期持久性的重要因素。这项研究不仅提供了一个配方的动态基板的发展有足够的时间框架，但也澄清了界面纳米结构，组成的纳米级PEG刷和带电的基础材料，影响生物相容性。
Dynamic substrates whose cell adhesiveness changes in response to an external stimulus are useful not only for patterning cells in various geometries but also for inducing cell migration or arraying heterotypic cells. The requirements for such applications are high switching efficiency in cell adhesiveness and long-term persistence of the created cellular patterns. In this study, we prepared a dynamic substrate bearing photocleavable poly(ethylene glycol) (PEG) and examined the effect of the surface PEG density and the charge of cationic base materials on the above-mentioned key requirements. An amino-terminated substrate with a certain amino group density and charge was functionalized with photocleavable PEG5K, with and without subsequent backfilling of photocleavable PEG2K. The PEG chains made the surface non-cell-adhesive, but subsequent near-UV irradiation of the substrate induced photocleavage of the PEG, eventually making the surface cell-adhesive. The substrates were analyzed by atomic force microscopy, contact angle measurements, ellipsometry, and zeta potential measurements, complemented with protein adsorption observations. Although the density of amino group in the base material affected both the grafting efficiency of the backfilling PEG and the electrokinetic potential mainly in the positive range, the latter mainly determined the protein- and cell-repelling abilities of the substrates. Furthermore, varying the surface compositions had almost no effect on the switching efficiency in the early stage of the culture, but it became more significant after culturing cells for a longer time; the cells fouled the nonirradiated PEGylated regions earlier on the surfaces with higher positive zeta potentials. These results indicate that the zeta potential is an essential factor in the long-term persistence of cellular patterns on photoactivatable substrates. This study not only provides a recipe for the development of a dynamic substrate with an adequate time frame but also clarifies how the interfacial nanoarchitectures, composed of the nanometer-scale PEG brushes and charged base materials, affect the biocompatibility.