中文摘要：

基于硅蚀刻及软光刻复制模塑技术,制备了4种聚二甲基硅氧烷（PDMS）微柱阵列型拓扑结构基底,其微柱名义直径为4μm或10μm,名义间距为4μm或7μm,名义高度为4μm。考察了人肝癌细胞株HepG2在拓扑结构基底与PDMS平面基底上的形态、生物合成和解毒相关分子标志物的分泌/表达。采用扫描电镜和相差显微图像分析发现,HepG2细胞接种于拓扑结构基底较之于平面基底上出现明显的形态铺展和极化程度变化。以ELISA检测显示,HepG2细胞在拓扑结构基底上的白蛋白分泌水平高于平面基底上的相应分泌量。用实时荧光定量PCR评价相关基因表达,发现HepG2细胞于拓扑结构基底上培养1-3天后,白蛋白、细胞色素P450第一家族A亚族蛋白多肽1和2（CYP1A1和CYP1A2）的mRNA表达量,高于平面基底上的相应表达值。在所研究结构尺寸范围的拓扑结构基底上,HepG2细胞较大的铺展面积和细胞圆度值以及较小的细胞长/短径比值伴随着较高的白蛋白分泌/表达量;较小的铺展面积和细胞圆度值以及较大的细胞长/短径比值却伴随着较高的CYP1A1和CYP1A2表达量。这些结果表明,基底拓扑结构是影响HepG2细胞形态及功能的重要微环境因素,并可成为基于肝细胞的反应器与微系统培养环境设计和细胞功能表型优化的有效工程化手段。

英文摘要：

The polydimethylsiloxane micropillar arrayed topographic substrates were fabricated here using silicon etching and soft lithography-based replica molding, in which the micropillar had a nominal pillar diameter of 4 or 10 μm, a nominal pillar spacing of 4 or 7 μm, and a nominal pillar height of 4 μm. Thereafter, the substrates were subjected to surface activation for the HepG2 hepatoma cells to be grown on, and its impact on the cellular morphology and the secretion/expression of biomarkers relevant to liver biosynthesis and detoxification was investigated. Imaging of scanning electron and phase contrast microscopies showed significant changes in both the morphological spreading and the polarization degree for cells that had been grown on the topographic substrates, when compared with those for cells that had been grown on the flat PDMS substrates. The enzyme linked immunosorbent assays revealed that abundance of the albumin secreted from cells grown on the topographic substrates was more than that from cells cultured on the flat substrates. Further examination by real-time PCR demonstrated dramatical increases in the expression of albumin, along with the CYP1A1 and CYP1A2 members of cytochrome P450 family, in cells grown for 24~72 h on the topographic substrates, as compared to those in cells on the flat substrates. It was found within the structural dimensions of the topographic substrates that the larger areas of spreading, the higher values of roundness, and the lower long/short shaft ratios were accompanied by increased secretion and expression of albumin, and conversely the lower spreading areas and roundness values, along with the higher long/short shaft ratios, had concomitance with the up-regulated expression of CYP1A1 and CYP1A2. These results suggest that substrate topography is an important microenvironmental factor for regulating the cellular morphology and functionality, and is thus assumed to serve as an effective engineering approach to tailor cell culture environments and optimize cellular func