Tuesday, February 10, 2015 - 2:00pm
Fung Auditorium, Powell-Focht Bioengineering Hall
Professor, Department of Mechanical Engineering/I-Bio
Pohang University of Science and Technology (POSTECH), South Korea
High-Throughput Imaging of Cellular Dynamics Using Microfabricated Platforms Based on a Cell-Friendly Photoresist
Many biological processes in multi-cellular organisms are regulated by various dynamic cellular processes. However, classical tissue culture system can only provide static environments where many dynamic events occur randomly, thus mechanistic study of dynamics of cellular dynamics has been limited. To overcome this limitation, we developed new experimental platforms where we can precisely position different types of cells and control their movement by illuminating light to predefined areas. A thin film of a cell-friendly photoresist PDMP (poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r-poly(ethylene glycol) methacrylate) was used. Upon UV exposure, PDMP thin films become soluble in near-neutral aqueous buffers such as PBS and tissue culture media with minimal cytotoxicity. To create micro-patterns on PDMP thin film, microscope projection photolithography (MPP) technique was used. By performing series of MPP on PDMP thin films and sequentially depositing cells on UV-irradiated regions, we could successfully create single cell arrays of adhering cells. Then, various dynamic cellular processes such as cell spreading, adherens junction formation, and collective cell migration were triggered by removing PDMP thin films surrounding cells in single cell arrays by UV illumination. Using this new dynamic cell-patterning technique in conjunction with an automated microscope equipped with a motorized stage, dynamics of each cellular process was imaged in high-throughput manners to collect large amounts of data in a single experiment. This method can be useful for screening drugs targeting dynamic processes of cells.
Prof. Doh received his bachelor’s degree in Chemical Engineering from Seoul National University in 1999. He then moved to MIT for his graduate work with Prof. Darrell J. Irvine in the development of multi-component protein micropatterned surfaces for the study of the immunological synapses formed in T cells during activation. He received his PhD in 2006 in Chemical Engineering/Program in Polymer Science and Technology. As a postdoctoral researcher, Dr. Doh studied homotypic interactions among activating T cells in the laboratory of Max Krummel at UC San Francisco from 2006-2008. In 2008, he joined POSTECH with a joint appointment in Interdisciplinary Bioscience and Bioengineering (I-Bio) and Mechanical Engineering. Currently, Prof. Doh’s group develops engineering tools such as microfabrication/imaging/mechanics to study fundamental aspects of immune cell behaviors and cell motility.