Seong Hyejeong, Higgins Stuart G, Penders Jelle, Armstrong James P K, Crowder Spencer W, Moore Axel C, Sero Julia E, Becce Michele, Stevens Molly M
ACS Nano. 2020 May 26;14(5):5371-5381. doi: 10.1021/acsnano.9b08689. Epub 2020 Apr 29.
High-aspect-ratio nanostructures have emerged as versatile platforms for intracellular sensing and biomolecule delivery. Here, we present a microfabrication approach in which a combination of reactive ion etching protocols were used to produce high-aspect-ratio, nondegradable silicon nanoneedle arrays with tip diameters that could be finely tuned between 20 and 700 nm. We used these arrays to guide the long-term culture of human mesenchymal stem cells (hMSCs). Notably, we used changes in the nanoneedle tip diameter to control the morphology, nuclear size, and F-actin alignment of interfaced hMSCs and to regulate the expression of nuclear lamina genes, Yes-associated protein (YAP) target genes, and focal adhesion genes. These topography-driven changes were attributed to signaling by Rho-family GTPase pathways, differences in the effective stiffness of the nanoneedle arrays, and the degree of nuclear membrane impingement, with the latter clearly visualized using focused ion beam scanning electron microscopy (FIB-SEM). Our approach to design high-aspect-ratio nanostructures will be broadly applicable to design biomaterials and biomedical devices used for long-term cell stimulation and monitoring.
高纵横比纳米结构已成为用于细胞内传感和生物分子递送的多功能平台。在此，我们展示了一种微加工方法，其中使用反应离子蚀刻协议的组合来生产高纵横比、不可降解的硅纳米针阵列，其尖端直径可在20至700纳米之间进行精细调节。我们使用这些阵列来指导人间充质干细胞（hMSCs）的长期培养。值得注意的是，我们利用纳米针尖端直径的变化来控制界面hMSCs的形态、核大小和F-肌动蛋白排列，并调节核纤层基因、Yes相关蛋白（YAP）靶基因和粘着斑基因的表达。这些由形貌驱动的变化归因于Rho家族GTPase途径的信号传导、纳米针阵列有效刚度的差异以及核膜撞击程度，后者使用聚焦离子束扫描电子显微镜（FIB-SEM）清晰可见。我们设计高纵横比纳米结构的方法将广泛适用于设计用于长期细胞刺激和监测的生物材料和生物医学装置。
