Futai Nobuyuki, Tamura Makoto, Ogawa Tomohisa, Tanaka Masato
Department of Mechanical Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan.
Department of Human Pathology, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan.
Micromachines (Basel). 2018 Dec 24;10(1):9. doi: 10.3390/mi10010009.
We have developed a cast microfluidic chip for concentration gradient generation that contains a thin (~5 µm² cross-sectional area) microchannel. The diffusion of diffused 185 nm ultraviolet (UV) light from an inexpensive low-pressure mercury lamp exposed a layer of the SU-8 photoresist from the backside and successfully patterned durable 2 µm-high microchannel mold features with smooth bell-shaped sidewalls. The thin channel had appropriate flow resistance and simultaneously satisfied both the rapid introduction of test substance and long-term maintenance of gradients. The average height and width at the half height of the channel, defined by a 2 µm-wide line mask pattern, were 2.00 ± 0.19 µm, and 2.14 ± 0.89 µm, respectively. We were able to maintain the concentration gradient of Alexa Fluor 488 fluorescent dye inside or at the exit of the thin microchannel in an H-shaped microfluidic configuration for at least 48 h. We also demonstrated the cultivation of chick embryo dorsal root ganglion neuronal cells for 96 h, and the directional elongation of axons under a nerve growth factor concentration gradient.
我们开发了一种用于产生浓度梯度的铸型微流控芯片，该芯片包含一个薄的（横截面积约为5 µm²）微通道。来自廉价低压汞灯的185 nm紫外光扩散后，从背面照射SU-8光刻胶层，并成功地制作出具有光滑钟形侧壁的耐用2 µm高的微通道模具特征。薄通道具有适当的流动阻力，同时满足了测试物质的快速引入和梯度的长期维持。由2 µm宽的线掩模图案定义的通道半高处的平均高度和宽度分别为2.00±0.19 µm和2.14±0.89 µm。我们能够在H形微流控结构的薄微通道内部或出口处维持Alexa Fluor 488荧光染料的浓度梯度至少48小时。我们还展示了鸡胚背根神经节神经元细胞96小时的培养，以及在神经生长因子浓度梯度下轴突的定向伸长。
