DNA aptamers are very specific towards biological targets and are useful in many biosensor applications. However, there had been little reports that systematically examined the potential of DNA aptamers as surface thin film for promoting cell-surface adhesion. In this work, three aptamers (IDA, NC3S and SYL3C) were grafted on silicon surface and were only selective towards epithelial cell type. To better demonstrate this selectivity, click chemistry on underlying PEG layer was performed to attach these DNA aptamers on the surfaces so as to discourage non-specific cell attachment. The physicochemical properties of the surfaces were examined via XPS, AFM, FTIR and contact angle goniometry. A range of different cell types (MDA-MB 231, A549, MES-SA, N2A and HaCaT) were incubated to these surfaces and their viability, morphology and focal adhesion protein expression levels were quantified after a period of 24 h. From our observations, we had shown that NC3S and SYL3C can actively promote cell adhesion while integrin targeting IDA did not help to improve the outcomes of cell-surface interaction. Moreover, aptamer functionalized surfaces were observed to be only favorably towards epithelial cell types and our current findings here had help shed light on DNA aptamer as potential bioactive thin films that are cell type selective.

中文翻译：

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硅表面 DNA 适体单层促进细胞表面相互作用的评估

DNA 适体对生物靶标具有很强的特异性，可用于许多生物传感器应用。然而，系统研究DNA适体作为表面薄膜促进细胞表面粘附的潜力的报道却很少。在这项工作中，三种适体（IDA、NC3S 和 SYL3C）被移植到硅表面，并且仅对上皮细胞类型具有选择性。为了更好地证明这种选择性，在底层 PEG 层上进行点击化学，将这些 DNA 适体附着在表面上，从而阻止非特异性细胞附着。通过 XPS、AFM、FTIR 和接触角测角法检查表面的物理化学性质。将一系列不同的细胞类型（MDA-MB 231、A549、MES-SA、N2A 和 HaCaT）在这些表面上孵育，24 小时后对它们的活力、形态和粘附斑蛋白表达水平进行定量。根据我们的观察，我们发现 NC3S 和 SYL3C 可以积极促进细胞粘附，而靶向 IDA 的整合素无助于改善细胞表面相互作用的结果。此外，据观察，适体功能化表面仅对上皮细胞类型有利，我们目前的发现有助于阐明 DNA 适体作为细胞类型选择性的潜在生物活性薄膜。