title: A microfluidic dual gradient generator for conducting cell-based drug combination assays.
abstract: We present a microfluidic chip that generates linear concentration gradients of multiple solutes that are orthogonally-aligned to each other. The kinetics of gradient formation was characterized using a fluorescent tracer matching the molecular weight of small inhibitory drugs. Live-cell signalling and motility experiments were conducted to demonstrate the potential uses and advantages of the device. A431 epidermoid carcinoma cells, where EGF induces apoptosis in a concentration-dependent manner, were simultaneously exposed to gradients of MEK inhibitor and EGF receptor (EGFR) inhibitor. By monitoring live caspase activation in the entire chip, we were able to quickly assess the combinatorial interaction between MEK and EGFR pathways, which otherwise would require costly and time consuming titration experiments. We also characterized the motility and morphology of MDA-MB-231 breast cancer cells exposed to orthogonal gradients of EGF and EGFR inhibitor. The microfluidic chip not only permitted the quantitative analysis of a population of cells exposed to drug combinations, but also enabled the morphological characterization of individual cells. In summary, our microfluidic device, capable of establishing concentration gradients of multiple compounds over a group of cells, facilitates and accelerates in vitro cell biology experiments, such as those required for cell-based drug combination assays.
authors.affiliation: School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland. gil.lee@ucd.ie.
authors.forename: Devrim
authors.initials: D
authors.lastname: Kilinc
authors.forename: Jefrem
authors.initials: J
authors.lastname: Schwab
authors.forename: Stefano
authors.initials: S
authors.lastname: Rampini
authors.forename: Oshoke W
authors.initials: OW
authors.lastname: Ikpekha
authors.forename: Ashwin
authors.initials: A
authors.lastname: Thampi
authors.forename: Agata
authors.initials: A
authors.lastname: Blasiak
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Robert
authors.initials: R
authors.lastname: Schwamborn
authors.forename: Walter
authors.initials: W
authors.lastname: Kolch
authors.forename: David
authors.initials: D
authors.lastname: Matallanas
authors.forename: Gil U
authors.initials: GU
authors.lastname: Lee
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D001681:Biological Assay / Q000295:instrumentation*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D004338:Drug Combinations; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation*; D006801:Humans; D056656:Lab-On-A-Chip Devices; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations