Department of Bioengineering, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, 113-8656, Japan.
Center for Disease Biology and Integrative Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Biomicrofluidics. 2013 Sep 23;7(5):54109. doi: 10.1063/1.4822033. eCollection 2013.
Hydrogels have several excellent characteristics suitable for biomedical use such as softness, biological inertness and solute permeability. Hence, integrating hydrogels into microfluidic devices is a promising approach for providing additional functions such as biocompatibility and porosity, to microfluidic devices. However, the poor mechanical strength of hydrogels has severely limited device design and fabrication. A tetra-poly(ethylene glycol) (tetra-PEG) hydrogel synthesized recently has high mechanical strength and is expected to overcome such a limitation. In this research, we have comprehensively studied the implementation of tetra-PEG gel into microfluidic device technology. First, the fabrication of tetra-PEG gel/PDMS hybrid microchannels was established by developing a simple and robust bonding technique. Second, some fundamental features of tetra-PEG gel/PDMS hybrid microchannels, particularly fluid flow and mass transfer, were studied. Finally, to demonstrate the unique application of tetra-PEG-gel-integrated microfluidic devices, the generation of patterned chemical modulation with the maximum concentration gradient: 10% per 20 μm in a hydrogel was performed. The techniques developed in this study are expected to provide fundamental and beneficial methods of developing various microfluidic devices for life science and biomedical applications.
水凝胶具有许多优异的特性，适合生物医学用途，如柔软性、生物惰性和溶质渗透性。因此，将水凝胶集成到微流控设备中是一种很有前途的方法，可以为微流控设备提供额外的功能，如生物相容性和多孔性。然而，水凝胶的机械强度差严重限制了器件的设计和制造。最近合成的四聚乙二醇（tetra-PEG）水凝胶具有较高的机械强度，有望克服这一限制。在这项研究中，我们全面研究了将四聚乙二醇水凝胶引入微流控器件技术。首先，通过开发一种简单而强大的键合技术，建立了四聚乙二醇水凝胶/PDMS 混合微通道的制造方法。其次，研究了四聚乙二醇水凝胶/PDMS 混合微通道的一些基本特性，特别是流体流动和质量传递。最后，为了展示集成四聚乙二醇水凝胶的微流控器件的独特应用，在水凝胶中产生了具有最大浓度梯度的图案化化学调制：每 20 μm 增加 10%。本研究中开发的技术有望为生命科学和生物医学应用的各种微流控器件的开发提供基础和有益的方法。
