Lee Seungjin, Ahn Jinseop, Kim Seok-Man, Kim Daehan, Yeom Jiun, Kim Jeongmok, Park Joong Yull, Ryu Buom-Yong
School of Mechanical Engineering, College of Engineering, Chung-Ang University, Seoul, 06974, Republic of Korea.
Present address: Columbia Center for Translational Immunology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA.
J Biol Eng. 2023 Aug 7;17(1):51. doi: 10.1186/s13036-023-00369-1.
Microfluidic devices have emerged as powerful tools for cell-based experiments, offering a controlled microenvironment that mimic the conditions within the body. Numerous cell experiment studies have successfully utilized microfluidic channels to achieve various new scientific discoveries. However, it has been often overlooked that undesired and unnoticed propagation of cellular molecules in such bio-microfluidic channel systems can have a negative impact on the experimental results. Thus, more careful designing is required to minimize such unwanted issues through deeper understanding and careful control of chemically and physically predominant factors at the microscopic scale. In this paper, we introduce a new approach to improve microfluidic channel design, specifically targeting the mitigation of the aforementioned challenges. To minimize the occurrence of undesired cell positioning upstream from the main test section where a concentration gradient field locates, an additional narrow port structure was devised between the microfluidic upstream channel and each inlet reservoir. This port also functioned as a passive lock that hold the flow at rest via fluid-air surface tension, which facilitated manual movement of the device even when cell attachment was not achieved completely. To demonstrate the practicability of the system, we conducted experiments and diffusion simulations on the effect of endocrine disruptors on germ cells. To this end, a bisphenol-A (BPA) concentration gradient was generated in the main channel of the system at BPA concentrations ranging from 120.8 μM to 79.3 μM, and the proliferation of GC-1 cells in the BPA gradient environment was quantitatively evaluated. The features and concepts of the introduced design is to minimize unexpected and ignored error sources, which will be one of the issues to be considered in the development of microfluidic systems to explore extremely delicate cellular phenomena.
微流控设备已成为基于细胞实验的强大工具，提供了一个模拟体内条件的可控微环境。众多细胞实验研究已成功利用微流控通道实现了各种新的科学发现。然而，人们常常忽略的是，在这种生物微流控通道系统中，细胞分子的意外且未被注意到的传播可能会对实验结果产生负面影响。因此，需要更仔细的设计，通过在微观尺度上更深入地理解和仔细控制化学和物理主导因素，将此类不必要的问题降至最低。在本文中，我们介绍一种改进微流控通道设计的新方法，特别针对减轻上述挑战。为了尽量减少在浓度梯度场所在的主测试段上游出现不需要的细胞定位情况，在微流控上游通道和每个入口储液器之间设计了一个额外的狭窄端口结构。这个端口还起到了被动锁的作用，通过流体 - 空气表面张力使流体保持静止，即使细胞未完全附着，这也便于手动移动设备。为了证明该系统的实用性，我们进行了关于内分泌干扰物对生殖细胞影响的实验和扩散模拟。为此，在系统的主通道中产生了双酚A（BPA）浓度梯度，其浓度范围为120.8 μM至79.3 μM，并对BPA梯度环境中GC - 1细胞的增殖进行了定量评估。所引入设计的特点和理念是尽量减少意外和被忽视的误差源，这将是在开发用于探索极其微妙的细胞现象的微流控系统时需要考虑的问题之一。
