Hatsuzawa Takeshi, Kurosaka Mikiya
Laboratory for Future Interdisciplinary Research of Science and Technology(FIRST), Tokyo Institute of Technology, 4259-R2-6, Nagatsuta-cho, midori-ku, Yokohama, 226-8503, Japan.
School of Engineering, Department of Mechanical Engineering, Tokyo Institute of Technology, 4259-R2-6, Nagatsuta-cho, midori-ku, Yokohama, 226-8503, Japan.
Biomed Microdevices. 2018 Jul 12;20(3):58. doi: 10.1007/s10544-018-0303-7.
A cell culture device equipped with a micro-needle electrode array was fabricated for the signal analysis of cell spheroids, cell masses, and cell sheets. For the analysis, sharp needle electrodes with a high aspect ratio for facilitating easy penetration into the cell mass and a small pitch for fine spatial resolution were required. Microelectromechanical systems (MEMS) technology is one of the common solutions for the fabrication of devices. However, an additional process, such as anisotropic etching or electro-polishing, is required for fabricating sharp needles. Tapered needles were fabricated using backside exposure for coating a layer of thick resist film on a glass substrate. The incident beam from mask apertures were diffracted and attenuated in the medium, resulting in tapered intensity distribution. A needle-like shape was obtained after performing resist development without using additional MEMS process. In this study, the theoretical analysis of optical intensity distribution and design and fabrication process of the device were described. Finally, the effectiveness of the device was evaluated by adding cultured cell mass on the needle array. Signals with spikes and fluctuations were observed in the electrode covered with cell mass, whereas only noise was observed on the non-covered electrode, demonstrating the signal pick-up ability of the device during cell culture.
制造了一种配备微针电极阵列的细胞培养装置，用于分析细胞球体、细胞团和细胞片的信号。为了进行分析，需要具有高纵横比以便于轻松穿透细胞团且间距小以实现精细空间分辨率的尖锐针状电极。微机电系统（MEMS）技术是制造此类装置的常见解决方案之一。然而，制造尖锐针需要额外的工艺，如各向异性蚀刻或电抛光。使用背面曝光在玻璃基板上涂覆一层厚抗蚀剂膜来制造锥形针。来自掩膜孔的入射光束在介质中发生衍射和衰减，从而产生锥形强度分布。在不使用额外MEMS工艺的情况下进行抗蚀剂显影后获得了针状形状。在本研究中，描述了光强分布的理论分析以及该装置的设计和制造过程。最后，通过在针阵列上添加培养的细胞团来评估该装置的有效性。在覆盖有细胞团的电极上观察到带有尖峰和波动的信号，而在未覆盖的电极上仅观察到噪声，这证明了该装置在细胞培养过程中的信号采集能力。
