title: Patterning alginate hydrogels using light-directed release of caged calcium in a microfluidic device.
abstract: This paper describes a simple reversible hydrogel patterning method for 3D cell culture. Alginate gel is formed in select regions of a microfluidic device through light-triggered release of caged calcium. In the pre-gelled alginate solution, calcium is chelated by DM-nitrophen (DM-n) to prevent cross-linking of alginate. After sufficient UV exposure the caged calcium is released from DM-n causing alginate to cross-link. The effect of using different concentrations of calcium and chelating agents as well as the duration of UV exposure is described. Since the cross-linking is based on calcium concentration, the cross-linked alginate can easily be dissolved by EDTA. We also demonstrate application of this capability to patterned microscale 3D co-culture using endothelial cells and osteoblastic cells in a microchannel.
authors.affiliation: Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Bor-han
authors.initials: BH
authors.lastname: Chueh
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.forename: Yu-suke
authors.initials: YS
authors.lastname: Torisawa
authors.forename: Amy Y
authors.initials: AY
authors.lastname: Hsiao
authors.forename: Chunxi
authors.initials: C
authors.lastname: Ge
authors.forename: Susan
authors.initials: S
authors.lastname: Hsiong
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Huebsch
authors.forename: Renny
authors.initials: R
authors.lastname: Franceschi
authors.forename: David J
authors.initials: DJ
authors.lastname: Mooney
authors.forename: Shuichi
authors.initials: S
authors.lastname: Takayama
mesh_terms: D000464:Alginates / Q000737:chemistry* / Q000528:radiation effects; D000818:Animals; D002118:Calcium / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000295:instrumentation* / Q000379:methods; D049109:Cell Proliferation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000502:physiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation*; D020723:Glucuronic Acid / Q000737:chemistry / Q000528:radiation effects; D006603:Hexuronic Acids / Q000737:chemistry / Q000528:radiation effects; D006801:Humans; D020100:Hydrogels / Q000737:chemistry / Q000528:radiation effects; D008027:Light; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020100:Hydrogels; D020723:Glucuronic Acid; D002118:Calcium