奈米表面影響NIH 3T3細胞之貼附並誘發細胞自然凋亡

Abstract

我們將老鼠胚胎纖維細胞 NIH 3T3 培養於奈米點陣列表面上，以研究其對奈米尺度的反應。奈米點陣列以陽極氧化鋁為模板，製造於鍍上 TaN 的矽晶圓上，其直徑分布介於10 到 200 nm 之間。在SEM 的觀察中，生長於平坦以及 10 nm 表面的細胞顯示出正常的形貌與良好的貼附。生長於超過 50 nm 奈米點陣列上的細胞卻表現出不正常的形貌，並有部份隆起未與底層粘著。螢光標定照片也顯示出這些細胞的微細絲發展較不健全，且具有較少量的附著點。我們懷疑這些細胞會因與大尺度的奈米表面貼附不良而產生自然凋亡。在自然凋亡的過程中扮演重要角色的 caspase-3，其活性在生長於超過 50 nm 奈米點陣列上的細胞之表現遠大於生長在小於 50 nm 表面上的細胞。若以細胞外基質的成分---collagen和fibronectin---修飾過的表面可幫助異常的細胞更平坦的貼附於底層上。這些細胞可藉由被幫助貼附而免於自然凋亡。奈米表面會干擾細胞骨架的發展並引起細胞不正常的形貌。

Mouse fibroblast NIH 3T3 cells were grown on nanodot arrays to investigate cellular response to nanolandscape. The nanodot arrays consisted of nanodots with diameters ranging from 10 to 200 nm which were fabricated by anodic aluminum oxide (AAO) processing on TaN-coated wafers. Cells seeded on flat wafer surface and on 10 nm nanodot arrays showed normal morphology and well attachment. Abnormal morphology and poor adhesion were observed on the cells cultured on arrays with dot size larger than 50 nm by SEM and immunofluorescent microscopy. The ratio of apoptotic cells were quantified by measuring their caspase-3 activity. Coating of fibronectin (FN) or type I collagen prevented the nanotopography-induced programmed cell death. The nanotopography-induced apoptosis can be overridden by forced cellular attachment. Nanotopography weakens cellular adhesion.