Efficient Dielectrophoretic Patterning of Embryonic Stem Cells in Energy Landscapes Defined by Hydrogel Geometries

• Published in: Annals of biomedical engineering 2010-12, Vol.38 (12), p.3777-3788
• Main Authors: Tsutsui, Hideaki, Yu, Edmond, Marquina, Sabrina, Valamehr, Bahram, Wong, Ieong, Wu, Hong, Ho, Chih-Ming
• Format: Article
• Language: English
• Subjects: Animals; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Biosensors; Cell microarray; Cell Movement; Cell Separation - instrumentation; Cell Separation - methods; Cell Survival; Classical Mechanics; Dielectrophoresis; Electrical properties; Electrophoresis; Embryonic Stem Cells - cytology; Embryonic Stem Cells - physiology; Finite Element Analysis; Flow rates; Hydrogels; Mice; Microfluidic Analytical Techniques; Microfluidics; Poly(ethylene glycol); Polyethylene Glycols; Static Electricity; Stem cells; Surface engineering
• ISSN: 0090-6964; 1573-9686
• DOI: 10.1007/s10439-010-0108-1

In this study, we have developed an integrated microfluidic platform for actively patterning mammalian cells, where poly(ethylene glycol) (PEG) hydrogels play two important roles as a non-fouling layer and a dielectric structure. The developed system has an embedded array of PEG microwells fabricated on a planar indium tin oxide (ITO) electrode. Due to its dielectric properties, the PEG microwells define electrical energy landscapes, effectively forming positive dielectrophoresis (DEP) traps in a low-conductivity environment. Distribution of DEP forces on a model cell was first estimated by computationally solving quasi-electrostatic Maxwell's equations, followed by an experimental demonstration of cell and particle patterning without an external flow. Furthermore, efficient patterning of mouse embryonic stem (mES) cells was successfully achieved in combination with an external flow. With a seeding density of 10⁷ cells/mL and a flow rate of 3 μL/min, trapping of cells in the microwells was completed in tens of seconds after initiation of the DEP operation. Captured cells subsequently formed viable and homogeneous monolayer patterns. This simple approach could provide an efficient strategy for fabricating various cell microarrays for applications such as cell-based biosensors, drug discovery, and cell microenvironment studies.