Efficient dielectrophoretic patterning of embryonic stem cells in energy landscapes defined by hydrogel geometries.

Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 90095, USA.
Annals of Biomedical Engineering (Impact Factor: 3.23). 12/2010; 38(12):3777-88. DOI: 10.1007/s10439-010-0108-1
Source: PubMed

ABSTRACT 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.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this manuscript we demonstrate the rapid formation of three-dimensional (3D) embryonic stem cell (ESC) aggregates with controllable sizes and shapes in hydrogels using dielectrophoresis (DEP). The ESCs encapsulated within a methacrylated gelatin (GelMA) prepolymer were introduced into the DEP device and, upon applying an electric field and crosslinking the GelMA hydrogel, formed 3D ESC aggregates. Embryonic bodies (EBs) fabricated using this method showed high cellular viability and pluripotency. The proposed technique enables production of EBs on a large-scale and in a high-throughput manner for potential cell therapy and tissue regeneration applications.
    Lab on a Chip 07/2014; 14(19). DOI:10.1039/C4LC00479E · 5.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microrobots are promising tools for the treatment of biological cells because of their lack of skill dependence, high throughput, and high repeatability. Integration of a microfluidic chip and robotics based on microelectromechanical systems technology is a key challenge for biomedical innovations. In addition to the advantage of environmental control by a microfluidic chip, robots enable physical operations on the cell with high throughput. This paper presents high-speed microrobotic actuation driven by permanent magnets in a microfluidic chip. The developed microrobot has a milli-Newton-level output force from a permanent magnet, micrometer-level positioning accuracy, and drive speed of over 280 mm/s. The riblet surface, which is a regularly arrayed V-groove, reduces fluid friction and enables high-speed actuation. Ni and Si composite fabrication was employed to form the optimum riblet shape on the microrobot's surface by wet and dry etching. The evaluation experiments show that the microrobot can be actuated at a rate of up to 90 Hz, which is more than ten times higher than that of the microrobot without a riblet. Two distinguish applications of the developed microrobots were demonstrated in a microfluidic chip.
    IEEE Transactions on Robotics 04/2013; 29(2):363-372. DOI:10.1109/TRO.2012.2228310 · 2.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A microfabricated device comprised of a microelectrode array (MEA) and a microfluidic channel is presented here for the purpose of trapping cells using positive dielectrophoresis (DEP). Transparent indium tin oxide (ITO) electrodes are patterned in an array of electrode pairs. A microfluidic channel made up of polydimethylsiloxane (PDMS) is then attached on top of the electrode array. DEP is used to trap P19 cells at specific positions on the ITO electrode array within the PDMS channel. Our method provides exact positioning of cells and better cell access. We show here the design and results on cell trapping with this novel microelectrode array.
    Neural Engineering (NER), 2013 6th International IEEE/EMBS Conference on; 01/2013

Full-text (2 Sources)

Available from
May 20, 2014