title: ECM-incorporated hydrogels cross-linked via native chemical ligation to engineer stem cell microenvironments.
abstract: Limiting the precise study of the biochemical impact of whole molecule extracellular matrix (ECM) proteins on stem cell differentiation is the lack of 3D in vitro models that can accommodate many different types of ECM. Here we sought to generate such a system while maintaining consistent mechanical properties and supporting stem cell survival. To this end, we used native chemical ligation to cross-link poly(ethylene glycol) macromonomers under mild conditions while entrapping ECM proteins (termed ECM composites) and stem cells. Sufficiently low concentrations of ECM were used to maintain constant storage moduli and pore size. Viability of stem cells in composites was maintained over multiple weeks. ECM of composites encompassed stem cells and directed the formation of distinct structures dependent on ECM type. Thus, we introduce a powerful approach to study the biochemical impact of multiple ECM proteins (either alone or in combination) on stem cell behavior.
authors.affiliation: Department of Biomedical Engineering, Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors.forename: Jangwook P
authors.initials: JP
authors.lastname: Jung
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Sprangers
authors.forename: John R
authors.initials: JR
authors.lastname: Byce
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.forename: Jayne M
authors.initials: JM
authors.lastname: Squirrell
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Messersmith
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Eliceiri
authors.forename: Brenda M
authors.initials: BM
authors.lastname: Ogle
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002470:Cell Survival; D002478:Cells, Cultured; D003432:Cross-Linking Reagents / Q000737:chemistry; D003470:Culture Media; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D057026:Induced Pluripotent Stem Cells / Q000502:physiology*; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D051379:Mice; D008856:Microscopy, Fluorescence; D011092:Polyethylene Glycols / Q000737:chemistry; D016062:Porosity; D013818:Thermogravimetry; D055682:Viscoelastic Substances / Q000737:chemistry; D014783:Viscosity
chemical_list: D003432:Cross-Linking Reagents; D003470:Culture Media; D016326:Extracellular Matrix Proteins; D020100:Hydrogels; D055682:Viscoelastic Substances; D011092:Polyethylene Glycols