title: Fabrication of 3D Controlled in vitro Microenvironments.
abstract: Microfluidics-based lab-on-a-chips have many advantages, one of which is to provide physiologically relevant settings for cell biology experiments. Thus there is an ever increasing interest in their fabrication. Our goal is to construct three dimensional (3D) Controlled in vitro Microenvironments (CivMs) that mimic the in vivo microenvironments. Here, we present our optimized fabrication method that works for various lab-on-a-chip designs with a wide range of dimensions. The most crucial points are:•While using one type of SU-8 photoresist (SU-2075), fine tuning of ramp, dwell time, spin speed, durations of soft bake, UV exposure and development allows fabrication of SU-8 masters with various heights from 40 to 600 μm.•Molding PDMS (polydimethylsiloxane) at room temperature for at least two days instead of baking at higher temperatures prevents not only tears and bubbles in PDMS stamps but also cracks in the SU-8 master.•3D nature of the CivMs is ensured by keeping the devices inverted during gel polymerization.
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology and Genetics, 35430 Izmir, Turkey.
authors.forename: Berrin
authors.initials: B
authors.lastname: Ozdil
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology and Genetics, 35430 Izmir, Turkey.
authors.forename: Sevgi
authors.initials: S
authors.lastname: Onal
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology and Genetics, 35430 Izmir, Turkey.
authors.forename: Tugce
authors.initials: T
authors.lastname: Oruc
authors.affiliation: Izmir Institute of Technology, Department of Molecular Biology and Genetics, 35430 Izmir, Turkey.
authors.forename: Devrim
authors.initials: D
authors.lastname: Pesen Okvur
keywords: Hydrogel; Lab-on-a-chip; Matrigel; Microenvironment; Microfluidic device; Polydimethylsiloxane; UV lithography