title: High-throughput generation of hydrogel microbeads with varying elasticity for cell encapsulation.
abstract: Elasticity of cellular microenvironments strongly influences cell motility, phagocytosis, growth and differentiation. Currently, the relationship between the cell behaviour and matrix stiffness is being studied for cells seeded on planar substrates, however in three-dimensional (3D) microenvironments cells may experience mechanical signalling that is distinct from that on a two-dimensional matrix. We report a microfluidic approach for high-throughput generation of 3D microenvironments with different elasticity for studies of cell fate. The generation of agarose microgels with different elastic moduli was achieved by (i) introducing into a microfluidic droplet generator two streams of agarose solutions, one with a high concentration of agarose and the other one with a low concentration of agarose, at varying relative volumetric flow rate ratios of the two streams, and (ii) on-chip gelation of the precursor droplets. At 37 degreesC, the method enabled a approximately 35-fold variation of the shear elastic modulus of the agarose gels. The application of the method was demonstrated by encapsulating two mouse embryonic stem cell lines within the agarose microgels. This work establishes a foundation for the high-throughput generation of combinatorial microenvironments with different mechanical properties for cell studies.
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kumachev
authors.forename: Jesse
authors.initials: J
authors.lastname: Greener
authors.forename: Ethan
authors.initials: E
authors.lastname: Tumarkin
authors.forename: Erika
authors.initials: E
authors.lastname: Eiser
authors.forename: Peter W
authors.initials: PW
authors.lastname: Zandstra
authors.forename: Eugenia
authors.initials: E
authors.lastname: Kumacheva
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D053595:Embryonic Stem Cells / Q000166:cytology*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D051379:Mice; D044085:Microfluidics / Q000379:methods*; D008863:Microspheres; D012685:Sepharose / Q000737:chemistry
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012685:Sepharose