Chen Weili, Long Kenneth D, Kurniawan Jonas, Hung Margaret, Yu Hojeong, Harley Brendan A, Cunningham Brian T
Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Adv Opt Mater. 2015 Nov;3(11):1623-1632. doi: 10.1002/adom.201500260. Epub 2015 Aug 22.
In this study, a planar-surface photonic crystal (PC) biosensor for quantitative, kinetic, label-free imaging of cell-surface interactions is demonstrated. The planar biosensor surface eliminates external stimuli to the cells caused by substrate topography to more accurately reflect smooth surface environment encountered by many cell types in vitro. Here, a fabrication approach that combines nanoreplica molding and a horizontal dipping process is used to planarize the surface of the PC biosensor. The planar PC biosensor maintains a high detection sensitivity that enables the monitoring of live cell-substrate interactions with spatial resolution sufficient for observing intracellular attachment strength gradients and the extensions of filopodia from the cell body. The evolution of cell morphology during the attachment and spreading process of 3T3 fibroblast cells is compared between planar and grating-structured PC biosensors. The planar surface effectively eliminates the directionally biased cellular attachment behaviors that are observed on the grating-structured surface. This work represents an important step forward in the development of label-free techniques for observing cellular processes without unintended external environmental modulation.
在本研究中，展示了一种用于细胞表面相互作用的定量、动力学、无标记成像的平面表面光子晶体（PC）生物传感器。平面生物传感器表面消除了由基底形貌对细胞造成的外部刺激，从而更准确地反映许多细胞类型在体外遇到的光滑表面环境。在此，采用一种结合纳米复制成型和水平浸渍工艺的制造方法来使PC生物传感器表面平整。平面PC生物传感器保持高检测灵敏度，能够以足以观察细胞内附着强度梯度和丝状伪足从细胞体伸出的空间分辨率监测活细胞与基底的相互作用。比较了3T3成纤维细胞在平面和光栅结构的PC生物传感器上附着和铺展过程中细胞形态的演变。平面表面有效地消除了在光栅结构表面观察到的定向偏向的细胞附着行为。这项工作代表了在开发用于观察细胞过程而无意外外部环境调制的无标记技术方面向前迈出的重要一步。
