Cite this: Lab Chip, 2013, 13, 2484 Recent developments in microfluidics-based chemotaxis studies Received 4th April 2013, Accepted 14th May 2013 DOI: 10.1039/c3lc50415h www.rsc.org/loc Jiandong Wu, ab Xun Wu ad and Francis Lin* abcd Microfluidic devices can better control cellular microenvironments compared to conventional cell migration assays. Over the past few years, microfluidics-based chemotaxis studies showed a rapid growth. New strategies were developed to explore cell migration in manipulated chemical gradients. In addition to expanding the use of microfluidic devices for a broader range of cell types, microfluidic devices were used to study cell migration and chemotaxis in complex environments. Furthermore, high-throughput microfluidic chemotaxis devices and integrated microfluidic chemotaxis systems were developed for medical and commercial applications. In this article, we review recent developments in microfluidics-based chemotaxis studies and discuss the new trends in this field observed over the past few years. Introduction Enabled by micrometer scale physics and chemistry, micro- fluidic devices can better control fluid behaviors such as chemical transport, reaction, and their mechanical and electrical properties. 1 Controlled fluidic environment is critical for studying the dynamic and complex behaviors of biological cells in response to environmental signals. 2 For example, chemical gradient directed cell migration (i.e. chemotaxis) critically participates in many physiological and pathological processes, 3–6 and chemotaxis research requires assays that can configure controlled chemical concentration gradients. Compared with conventional cell migration assays, 6–9 micro- fluidic devices provide a new experimental platform for quantitative cell migration and chemotaxis studies under better controlled gradient conditions. 10 Since the demonstration of highly controlled chemical gradient generation in microfluidic devices more than a decade ago, 11 various designs and strategies of microfluidic a Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. E-mail: flin@physics.umanitoba.ca; Fax: +1 204-474-7622; Tel: +1 204-474-9895 b Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada c Department of Biological Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada d Department of Immunology, University of Manitoba, Winnipeg, MB, R3E 0T5, Canada Jiandong Wu received his under- graduate degree in Electronic and Information Engineering from the University of Science and Technology of China in 2005. He did his Master’s research in the Laboratory of Fiber and Photoelectron Technology at the Anhui Institute of Optics & Fine Mechanics, Chinese Academy of Sciences, and was awarded the M.Sc. degree in 2009. Jiandong joined Francis Lin’s lab at the University of Manitoba in Canada in July 2011 and is currently a Ph.D. student. Jiandong’s current research focuses on developing compact and integrated multi- functional microfluidic systems for biological and biomedical applications. Xun Wu received her Bachelor’s degree in Medicine from Anhui Medical University in China in 2010. Xun joined Francis Lin’s lab at the University of Manitoba in Canada in September 2011 as a M.Sc. student. Xun’s current research focuses on studying the CCR7-mediated guiding mechan- isms for lymphocyte migration using microfluidic devices. Jiandong Wu Xun Wu Lab on a Chip CRITICAL REVIEW 2484 | Lab Chip, 2013, 13, 2484–2499 This journal is ß The Royal Society of Chemistry 2013 Published on 28 May 2013. Downloaded by Seoul National University on 22/01/2014 23:17:51. View Article Online View Journal | View Issue