title: Biocompatibility of fluids for multiphase drops-in-drops microfluidics.
abstract: This paper addresses the biocompatibility of fluids and surfactants in the context of microfluidics and more specifically in a drops-in-drops system for mammalian cell based drug screening. In the drops-in-drops approach, three immiscible fluids are used to manipulate the flow of aqueous microliter-sized drops; it enables merging of drops containing cells with drops containing drugs within a Teflon tube. Preliminary tests showed that a commonly-used fluid and surfactant combination resulted in significant variability in gene expression levels in Jurkat cells after exposure to a drug for four hours. This result led to further investigations of potential fluid and surfactant combinations that can be used in microfluidic systems for medium to long-term drug screening. Results herein identify a fluid combination, HFE-7500 and 5-cSt silicone oil + 0.25% Abil EM180, which enabled the drops-in-drops approach; this combination also allowed gene expression at normal levels comparable with the conventional drug screening in both magnitude and variability.
authors.affiliation: Osney Thermo-Fluids Laboratory, Department of Engineering Science, University of Oxford, Osney Mead, Oxford, OX2 0ES, UK.
authors.forename: Aishah
authors.initials: A
authors.lastname: Prastowo
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
authors.forename: Alexander
authors.initials: A
authors.lastname: Feuerborn
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Cook
authors.affiliation: Osney Thermo-Fluids Laboratory, Department of Engineering Science, University of Oxford, Osney Mead, Oxford, OX2 0ES, UK. edmond.walsh@eng.ox.ac.uk.
authors.forename: Edmond J
authors.initials: EJ
authors.lastname: Walsh
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D006801:Humans; D019169:Jurkat Cells; D056656:Lab-On-A-Chip Devices; D008422:Materials Testing / Q000295:instrumentation*; D051379:Mice; D013501:Surface-Active Agents / Q000494:pharmacology
chemical_list: D013501:Surface-Active Agents
keywords: Biocompatibility; Drops-in-drops; Drug screening; Mammalian cell; Surfactant; Toxicity