Department of Mechanical Engineering, McMaster University, Hamilton, ON, Canada.
Lab Chip. 2010 Feb 7;10(3):341-8. doi: 10.1039/b918291h. Epub 2009 Nov 27.
Cell based screening assays are increasingly used in drug discovery due to the physiological significance of the results and high content information obtained from them. Miniaturization of this format, currently carried out in microwell plates, is at its limit due to increased unnatural interaction of cells with walls inside micro-wells. In order to overcome this limitation, we present a new format for dynamically controlled, precise, spatial and temporal dosing of a continuous cell culture layer, using microfluidics. The device consists of a micropatterned nanoporous membrane layer that allows specific spatial locations in the continuous gel layer above, to be chemically addressed by external electric field through a microfluidic network below it. We demonstrate that the control of electric field across the nanoporous membrane leads to extremely precise dosing (approximately 50 microg accuracy). Spot sizes of 200 microm to 6 mm in diameter and inter-spot distances of 0.4-10 mm have been obtained. Microarray spot densities of 156 spots/cm(2) were obtained, which is five times higher than the densities used in current cell based assays. The capability of this method in handling small molecules, proteins and drugs is also demonstrated. This format of spatial dosing of continuous cell culture will enable further miniaturization of cell based assays and aid in high-throughput high-content screening.
基于细胞的筛选测定法由于其结果的生理相关性以及可以从其中获取的丰富信息，在药物发现中得到了越来越多的应用。这种方法已经被微缩到微孔板的形式，但由于细胞与微井内的壁之间的非自然相互作用增加，其进一步的微缩化已经达到了极限。为了克服这一限制，我们使用微流控技术提出了一种新的格式，用于对连续细胞培养层进行动态控制、精确、时空给药。该设备由一个微图案化的纳米多孔膜层组成，允许在其上方的连续凝胶层中的特定空间位置通过其下方的微流控网络被外部电场进行化学寻址。我们证明，控制穿过纳米多孔膜的电场会导致极其精确的给药（约 50 微克的精度）。已经获得了 200 微米至 6 毫米直径的斑点大小和 0.4-10 毫米的斑点间距离。获得了 156 个斑点/平方厘米的微阵列斑点密度，是当前基于细胞的测定中使用的密度的五倍。该方法处理小分子、蛋白质和药物的能力也得到了证明。这种连续细胞培养的空间给药格式将能够进一步实现基于细胞的测定的微型化，并有助于高通量高内涵筛选。
