Graduate School of Science and Technology, Hirosaki University, Aomori, 0368561, Japan.
Lab Chip. 2016 Jul 7;16(13):2481-6. doi: 10.1039/c6lc00481d. Epub 2016 Jun 6.
Microfluidic frameworks known as micro-total-analysis-systems or lab-on-a-chip have become versatile tools in cell biology research, since functional biochips are able to streamline dynamic observations of various cells. Glass or polymers are generally used as the substrate due to their high transparency, chemical stability and cost-effectiveness. However, these materials are not well suited for the microscopic observation of cell migration at the fluid boundary due to the refractive index mismatch between the medium and the biochip material. For this reason, we have developed a new method of fabricating three-dimensional (3D) microfluidic chips made of the low refractive index fluoric polymer CYTOP. This novel fabrication procedure involves the use of a femtosecond laser for direct writing, followed by wet etching with a dilute fluorinated solvent and annealing, to create high-quality 3D microfluidic chips inside a polymer substrate. A microfluidic chip made in this manner enabled us to more clearly observe the flagellum motion of a Dinoflagellate moving in circles near the fluid surface compared to the observations possible using conventional microfluidic chips. We believe that CYTOP microfluidic chips made using this new method may allow more detailed analysis of various cell migrations near solid boundaries.
微流控框架，又称微全分析系统或芯片实验室，已成为细胞生物学研究中的多功能工具，因为功能生物芯片能够简化对各种细胞的动态观察。由于其高透明度、化学稳定性和成本效益，玻璃或聚合物通常被用作基底材料。然而，由于介质和生物芯片材料之间的折射率不匹配，这些材料并不适合在流体边界处进行细胞迁移的微观观察。出于这个原因，我们开发了一种制造由低折射率氟聚合物 CYTOP 制成的三维（3D）微流控芯片的新方法。这种新颖的制造工艺涉及使用飞秒激光进行直接写入，然后使用稀释的氟化溶剂进行湿法刻蚀和退火，以在聚合物基底内创建高质量的 3D 微流控芯片。与使用传统微流控芯片进行的观察相比，用这种方式制造的微流控芯片使我们能够更清楚地观察到在靠近流体表面的圆形运动的鞭毛虫的鞭毛运动。我们相信，使用这种新方法制造的 CYTOP 微流控芯片可能允许更详细地分析各种靠近固体边界的细胞迁移。
