title: Micropatterning of 3D Microenvironments for Living Biosensor Applications.
abstract: Micro-scale printing and patterning of living cells has multiple applications including tissue engineering, cell signaling assays, and the fabrication of cell-based biosensors. In this work, a molecular printing instrument, the Bioforce Nano eNabler, was modified to enable micron-scale -quill-pen based printing of mammalian cells in a 3D hyaluronan/gelatin based hydrogel. Specifically, photo-initiated -thiol-ene click chemistry was used to couple the thiol groups of thiolated hyaluronan/thiolated gelatin to the alkene groups of 4-arm polyethylene glycol (PEG)-norbornene molecules. Rapid photopolymerization enabled direct printing and controlled curing of living cells within the hydrogel matrix. The resulting hydrogels were biocompatible with human adipose-derived stem cells, NIH-3T3 cells, and mouse embryonic stem cells. The utility of this printing approach was also explored for cell-based biosensors. Micro-printed cells expressing a redox sensitive variant of the green fluorescent protein (roGFP-R12) showed a measurable fluorescent response to addition of oxidizing and then reducing agents. This work represents a novel approach to micron-scale cell patterning, and its potential for living, cell-based biosensors.
authors.affiliation: State University of New York (SUNY) College of Nanoscale Science & Engineering, 237 Fuller Road, Albany, NY 12203, USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Hynes
authors.affiliation: BioTime, Inc., 1301 Harbor Bay Parkway, Alameda, CA 94502, USA.
authors.forename: Nate J
authors.initials: NJ
authors.lastname: Doty
authors.affiliation: BioTime, Inc., 1301 Harbor Bay Parkway, Alameda, CA 94502, USA.
authors.forename: Thomas I
authors.initials: TI
authors.lastname: Zarembinski
authors.affiliation: Wisconsin Institutes of Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schwartz
authors.affiliation: Wisconsin Institutes of Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Toepke
authors.affiliation: Wisconsin Institutes of Medical Research, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA.
authors.forename: William L
authors.initials: WL
authors.lastname: Murphy
authors.affiliation: BioTime, Inc., 1301 Harbor Bay Parkway, Alameda, CA 94502, USA.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Atzet
authors.affiliation: State University of New York (SUNY) College of Nanoscale Science & Engineering, 237 Fuller Road, Albany, NY 12203, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Clark
authors.affiliation: State University of New York (SUNY) College of Nanoscale Science & Engineering, 237 Fuller Road, Albany, NY 12203, USA.
authors.forename: J Andres
authors.initials: JA
authors.lastname: Melendez
authors.affiliation: State University of New York (SUNY) College of Nanoscale Science & Engineering, 237 Fuller Road, Albany, NY 12203, USA.
authors.forename: Nathaniel C
authors.initials: NC
authors.lastname: Cady
keywords: Irgacure; PEG norbornene; ROS; biosensor; gelatin; hyaluronan; hyaluronic acid; hydrogel; microprinting; reactive oxygen species; roGFP-R12