2014 concentration gradient 水凝胶.pdfVIP

Microfluid Nanofluid (2014) 16:645–654 DOI 10.1007/s10404-013-1265-y RESEARCH PAPER Rapid and accurate generation of various concentration gradients using polydimethylsiloxane-sealed hydrogel device Minseok Kim • Mingjie Jia • Youngmi Kim • Taesung Kim Received: 29 April 2013 / Accepted: 10 September 2013 / Published online: 20 September 2013 Springer-Verlag Berlin Heidelberg 2013 Abstract We report a microfluidic device that can rap- also the versatile concentration gradient generation device idly and accurately generate various concentration gradi- can be used for various studies on interaction between ents in a controllable manner for the chemotaxis study of chemicals and cells including bacterial chemotaxis assays. motile bacterial cells by integrating hydrogel into poly- dimethylsiloxane (PDMS) microchannels. We performed Keywords Microfluidics Hydrogel numerical simulations for both the PDMS-sealed hydrogel Polydimethylsiloxane Concentration gradient hybrid device and a representative conventional hydrogel- Chemotaxis based device to theoretically compare their characteristics. In addition, we experimentally demonstrated that the PDMS-sealed hydrogel device not only produces various 1 Introduction linear and nonlinear concentration gradients without flow- induced shear stresses on motile bacterial cells but also Bacterial chemotaxis is a model that clarifies how cells and exhibits remarkable advantages over conventional hydro- microorganisms sense and respond to concentration gra- gel-based devices. For example, the PDMS-sealed hydro- dients in chemical environments (Adler 1966; Ahmed et al. gel device can be used for fast and accurate generation of 2010b). Apart from the studies on the chemotaxis of sur- various concentr