ABSTRACT
In order to match the controllability of traditional pipetting with the advantages of microfluidics, we introduce the concept of polymer based chemical delivery to multichannel capillary patterned cells. Here we demonstrate that UV polymerized hydrogel can be used as a miniature pipet to deliver picolitre chemical quantities to multichannel capillary patterned cells.
Subject(s)
Cell Culture Techniques/instrumentation , Hydrogel, Polyethylene Glycol Dimethacrylate/chemistry , Microfluidic Analytical Techniques/instrumentation , Acyl-Butyrolactones/chemistry , Acyl-Butyrolactones/metabolism , Equipment Design , Escherichia coli/cytology , Fluorescein/chemistry , Tissue Array Analysis/instrumentationABSTRACT
In order to offer an easier way to study interactions between multiple cellular populations, we have developed a novel method to precisely place cells in a variety of nonoverlapping patterns using surface tension in laterally open microchannels. Our design is fundamentally different from previous strategies such as compartmentalization, stamping, stenciling, or mechanical approaches. It relies on capillary action or the propensity for liquid to move more readily through narrow spaces as a result of surface tension. Until now, capillary based patterning has been limited to coating chemically isolated areas. Here, we demonstrate, through use of surface tension and controlled flooding, that it is possible to pattern multiple cells and proteins using laterally open channels in a variety of designs. We demonstrate the relevance of the concept by coculturing different mammalian cell types and evaluating the behavior of engineered quorum sensing circuits in E. coli. In the future, we believe the laterally open channel designs shown here can be useful for rapidly creating and studying cellular ecologies using simple pipetting.
Subject(s)
Microfluidic Analytical Techniques/methods , Animals , Coculture Techniques , Dimethylpolysiloxanes/chemistry , Extracellular Matrix/chemistry , Fibronectins/chemistry , HeLa Cells , Humans , Mice , Microfluidic Analytical Techniques/instrumentation , NIH 3T3 Cells , Polylysine/chemistry , Surface TensionABSTRACT
An optofluidic maskless photopolymerization process was developed for in situ negatively charged nanoporous hydrogel [poly-AMPS (2-acrylamido-2-methyl-1-propanesulfonic acid)] fabrication. The optofluidic maskless lithography system, which combines a high power UV source and digital mirror device, enables fast polymerization of arbitrary shaped hydrogels in a microfluidic device. The poly-AMPS hydrogel structures were positioned near the intersections of two microchannels, and were used as a cation-selective filter for biological sample preconcentration. Preconcentration dynamics as well as the fabricated polymer shape were analyzed in three-dimensions using fluorescein sample and a confocal microscope. Finally, single-stranded DNA preconcentration was demonstrated for polymerase chain reaction-free signal enhancement.
