title: Cell micropatterning inside a microchannel and assays under a stable concentration gradient.
abstract: We describe the use of a microfluidic device to micropattern cells in a microchannel and investigated the behavior of these cells under a concentration gradient. The microfluidic device consisted of 3 parts: a branched channel for generating a stable concentration gradient, a main channel for culturing cells, and 2 side channels that flowed into the main channel. The main channel was coated with a cross-linked albumin that was initially cell-repellent but that could become cell-adherent by electrostatic adsorption of a polycation. A sheath flow stream, which was generated by introducing a polycation solution from the branched channel and a buffer solution from the 2 side channels, was used to change a specific region in the main channel from cell-repellent to cell-adhesive. In this way, cells attached to the central region along the main channel. The remaining surface was subsequently changed to cell-adhesive, thereby facilitating cell migration from a fixed location under a concentration gradient. We demonstrated that with this device, the gradient generator could be used to conduct simultaneous cytotoxic assays with anticancer agents; further, by combining this device with cell micropatterning, migration assays under a concentration gradient of biological factors could be conducted.
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Okuyama
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamazoe
authors.forename: Yuki
authors.initials: Y
authors.lastname: Seto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Junji
authors.initials: J
authors.lastname: Fukuda
mesh_terms: D001681:Biological Assay / Q000295:instrumentation*; D015374:Biosensing Techniques / Q000295:instrumentation*; D018929:Cell Culture Techniques / Q000295:instrumentation*; D016764:Cell Polarity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation*; D046228:Microarray Analysis / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008904:Miniaturization; D010477:Perfusion / Q000295:instrumentation*