title: High Throughput, Polymeric Aqueous Two-Phase Printing of Tumor Spheroids.
abstract: This paper presents a new 3D culture microtechnology for high throughput production of tumor spheroids and validates its utility for screening anti-cancer drugs. We use two immiscible polymeric aqueous solutions and microprint a submicroliter drop of the "patterning" phase containing cells into a bath of the "immersion" phase. Selecting proper formulations of biphasic systems using a panel of biocompatible polymers results in the formation of a round drop that confines cells to facilitate spontaneous formation of a spheroid without any external stimuli. Adapting this approach to robotic tools enables straightforward generation and maintenance of spheroids of well-defined size in standard microwell plates and biochemical analysis of spheroidsin situ, which is not possible with existing techniques for spheroid culture. To enable high throughput screening, we establish a phase diagram to identify minimum cell densities within specific volumes of the patterning drop to result in a single spheroid. Spheroids show normal growth over long-term incubation and dose-dependent decrease in cellular viability when treated with drug compounds, but present significant resistance compared to monolayer cultures. The unprecedented ease of implementing this microtechnology and its robust performance will benefit high throughput studies of drug screening against cancer cells with physiologically-relevant 3D tumor models.
authors.affiliation: Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Atefi
authors.affiliation: Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lemmo
authors.affiliation: Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA.
authors.forename: Darcy
authors.initials: D
authors.lastname: Fyffe
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, MI 48105 USA ; Microbiology and Immunology, University of Michigan, Ann Arbor, MI 48105 USA ; Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105 USA.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Luker
authors.affiliation: Department of Biomedical Engineering, The University of Akron, Akron, OH 44325 USA.
authors.forename: Hossein
authors.initials: H
authors.lastname: Tavana
keywords: 3D culture; Aqueous two-phase system; Drug screening; High throughput; Tumor Spheroid