title: A microfluidic pipette for single-cell pharmacology.
abstract: We report on a free-standing microfluidic pipette made in poly(dimethylsiloxane) having a circulating liquid tip that generates a self-confining volume in front of the outlet channels. The method is flexible and scalable as the geometry and the size of the recirculation zone is defined by pressure, channel number, and geometry. The pipette is capable of carrying out a variety of complex fluid processing operations, such as mixing, multiplexing, or gradient generation at selected cells in cell and tissue cultures. Using an uptake assay, we show that it is possible to generate dose-response curves in situ from adherent Chinese hamster ovary cells expressing proton-activated human transient receptor potential vanilloid (hTRPV1) receptors. Using confined superfusion and cell stimulation, we could activate hTRPV1 receptors in single cells, measure the response by a patch-clamp pipette, and induce membrane bleb formation by exposing selected groups of cells to formaldehyde/dithiothreitol-containing solutions, respectively. In short, the microfluidic pipette allows for complex, contamination-free multiple-compound delivery for pharmacological screening of intact adherent cells.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivagen 10, SE-412 96 Goteborg, Sweden.
authors.forename: Alar
authors.initials: A
authors.lastname: Ainla
authors.forename: Erik T
authors.initials: ET
authors.lastname: Jansson
authors.forename: Natalia
authors.initials: N
authors.lastname: Stepanyants
authors.forename: Owe
authors.initials: O
authors.lastname: Orwar
authors.forename: Aldo
authors.initials: A
authors.lastname: Jesorka
mesh_terms: D000818:Animals; D001692:Biological Transport; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D055724:Electrophysiological Phenomena; D006801:Humans; D046210:Microfluidic Analytical Techniques; D010600:Pharmacology / Q000295:instrumentation*; D050916:TRPV Cation Channels / Q000378:metabolism
chemical_list: D004129:Dimethylpolysiloxanes; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; C013830:baysilon