title: DNA-templated assembly of droplet-derived PEG microtissues.
abstract: Patterning multiple cell types is a critical step for engineering functional tissues, but few methods provide three-dimensional positioning at the cellular length scale. Here, we present a "bottom-up" approach for fabricating multicellular tissue constructs that utilizes DNA-templated assembly of 3D cell-laden hydrogel microtissues. A flow focusing-generated emulsion of photopolymerizable prepolymer is used to produce 100 μm monodisperse microtissues at a rate of 100 Hz (10(5) h(-1)). Multiple cell types, including suspension and adherently cultured cells, can be encapsulated into the microtissues with high viability (~97%). We then use a DNA coding scheme to self-assemble microtissues "bottom-up" from a template that is defined using "top-down" techniques. The microtissues are derivatized with single-stranded DNA using a biotin-streptavidin linkage to the polymer network, and are assembled by sequence-specific hybridization onto spotted DNA microarrays. Using orthogonal DNA codes, we achieve multiplexed patterning of multiple microtissue types with high binding efficiency and >90% patterning specificity. Finally, we demonstrate the ability to organize multicomponent constructs composed of epithelial and mesenchymal microtissues while preserving each cell type in a 3D microenvironment. The combination of high throughput microtissue generation with scalable surface-templated assembly offers the potential to dissect mechanisms of cell-cell interaction in three dimensions in healthy and diseased states, as well as provides a framework for templated assembly of larger structures for implantation.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA.
authors.forename: Cheri Y
authors.initials: CY
authors.lastname: Li
authors.forename: David K
authors.initials: DK
authors.lastname: Wood
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Hsu
authors.forename: Sangeeta N
authors.initials: SN
authors.lastname: Bhatia
mesh_terms: D000818:Animals; D001710:Biotin / Q000737:chemistry / Q000378:metabolism; D002450:Cell Communication; D002460:Cell Line; D004277:DNA, Single-Stranded / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D011092:Polyethylene Glycols / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry / Q000378:metabolism
chemical_list: D004277:DNA, Single-Stranded; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D001710:Biotin; D019809:Streptavidin