Density control of poly(ethylene glycol) layer to regulate cellular attachment
Density control of poly(ethylene glycol) layer to regulate cellular attachment
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DOI：
10.1021/la0624384
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发表时间：
2007-06-05
期刊：
影响因子：
3.9
通讯作者：
Kataoka, Kazunori
中科院分区：
文献类型：
--
作者：
Satomi, Tomomi;Nagasaki, Yukio;Kataoka, Kazunori
各种各样的细胞通常整合并响应于微尺度环境，如可溶性蛋白因子、细胞外基质蛋白以及与邻近细胞的接触。为了深入了解细胞微环境的设计，我们研究了二维微阵列形成的内皮细胞上的微图案的聚（乙二醇）（PEG）刷表面，PEG链密度和细胞附着之间的关系。图案化的基底由两个区域组成：PEG表面作为抗细胞层，暴露的基底表面促进蛋白质或细胞吸附。使用在链末端具有巯基的PEG在金基底上构建PEG刷涂层。PEG刷层的密度随着PEG在金基底上的重复吸附/冲洗循环而显著增加，从而显著减少非特异性蛋白质吸附。这些重复的吸附/冲洗循环通过使用更长（5 kDa）和更短（2kDa）的PEG来构建具有不同链密度的PEG层来进一步调节，并且随后的微图案化通过等离子体蚀刻通过微图案化的金属掩模来实现。PEG链密度对细胞附着图案形成的影响在内皮细胞的微图案上确定。结果表明，细胞图案的形成强烈依赖于PEG链密度和蛋白质吸附的程度。值得注意的是，PEG链密度高到足以抑制内皮细胞从细胞粘附区域在水平方向上的生长，可以仅通过在预构建的较长PEG刷层中形成短的PEG填料层来获得，这几乎完全阻止了非特异性蛋白质吸附。以这种方式，获得了具有长期存活力的完全微图案化的内皮细胞阵列。这清楚地表明了短的底刷PEG层在最大限度地减少非特异性蛋白质吸附以长期维持活性细胞模式方面的重要性。本文提出的细胞图案化策略可用于组织工程中研究细胞-细胞和细胞-表面相互作用。它也适用于高通量筛选和临床诊断，以及生物医学微系统的细胞和微加工组件的接口。
A wide variety of cells usually integrate and respond to the microscale environment, such as soluble protein factors, extracellular matrix proteins, and contacts with neighboring cells. To gain insight into cellular microenvironment design, we investigated two-dimensional microarray formation of endothelial cells on a micropatterned poly(ethylene glycol) (PEG)-brushed surface, based on the relationship between PEG chain density and cellular attachment. The patterned substrates consisted of two regions: the PEG surface that acts as a cell-resistant layer and the exposed substrate surface that promotes protein or cell adsorption. A PEG-brushed layer was constructed on a gold substrate using PEG with a mercapto group at the end of the chain. The density of the PEG-brushed layer increased substantially with repetitive adsorption/rinse cycles of PEG on the gold substrate, allowing marked reduction of nonspecific protein adsorption. These repeated adsorption/rinse cycles were further regulated by using longer (5 kDa) and shorter (2 kDa) PEG to construct PEG layers with different chain density, and subsequent micropatterning was achieved by plasma etching through a micropatterned metal mask. The effects of PEG chain density on pattern formation of cell attachment were determined on micropatterning of endothelial cells. The results indicated that cell pattern formation was strongly dependent on the PEG chain density and on the extent of protein adsorption. Notably, a PEG chain density high enough to inhibit outgrowth of endothelial cells from the cell-adhering region in the horizontal direction could be obtained only by employing formation of a short filler layer of PEG in the preconstructed longer PEG-brushed layer, which prevented nonspecific protein adsorption almost completely. In this way, a completely micropatterned array of endothelial cells with long-term viability was obtained. This clearly indicated the importance of a short underbrushed PEG layer in minimizing nonspecific protein adsorption for long-term maintenance of the active cell pattern. The strategy for cell patterning presented here can be employed in tissue engineering to study cell-cell and cell-surface interactions. It is also applicable for high-throughput screening and clinical diagnostics, as well as interfacing cellular and microfabricated components of biomedical microsystems.