title: Stable engineered vascular networks from human induced pluripotent stem cell-derived endothelial cells cultured in synthetic hydrogels.
abstract: Here, we describe an in vitro strategy to model vascular morphogenesis where human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) are encapsulated in peptide-functionalized poly(ethylene glycol) (PEG) hydrogels, either on standard well plates or within a passive pumping polydimethylsiloxane (PDMS) tri-channel microfluidic device. PEG hydrogels permissive towards cellular remodeling were fabricated using thiol-ene photopolymerization to incorporate matrix metalloproteinase (MMP)-degradable crosslinks and CRGDS cell adhesion peptide. Time lapse microscopy, immunofluorescence imaging, and RNA sequencing (RNA-Seq) demonstrated that iPSC-ECs formed vascular networks through mechanisms that were consistent with in vivo vasculogenesis and angiogenesis when cultured in PEG hydrogels. Migrating iPSC-ECs condensed into clusters, elongated into tubules, and formed polygonal networks through sprouting. Genes upregulated for iPSC-ECs cultured in PEG hydrogels relative to control cells on tissue culture polystyrene (TCP) surfaces included adhesion, matrix remodeling, and Notch signaling pathway genes relevant to in vivo vascular development. Vascular networks with lumens were stable for at least 14days when iPSC-ECs were encapsulated in PEG hydrogels that were polymerized within the central channel of the microfluidic device. Therefore, iPSC-ECs cultured in peptide-functionalized PEG hydrogels offer a defined platform for investigating vascular morphogenesis in vitro using both standard and microfluidic formats.
  
  
  CONCLUSIONS
  Human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) cultured in synthetic hydrogels self-assemble into capillary networks through mechanisms consistent with in vivo vascular morphogenesis.
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Zanotelli
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA.
authors.forename: Hamisha
authors.initials: H
authors.lastname: Ardalani
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Jue
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Zhonggang
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Nguyen
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Swanson
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Bao Kim
authors.initials: BK
authors.lastname: Nguyen
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bolin
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Angela
authors.initials: A
authors.lastname: Elwell
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA.
authors.forename: Lauren L
authors.initials: LL
authors.lastname: Bischel
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA.
authors.forename: Angela W
authors.initials: AW
authors.lastname: Xie
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA.
authors.forename: Ron
authors.initials: R
authors.lastname: Stewart
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Beebe
authors.affiliation: Morgridge Institute for Research, Madison, WI, USA; Department of Cell and Regenerative Biology, University of Wisconsin-Madison, WI, USA; Department of Molecular, Cellular, and Developmental Biology, University of California-Santa Barbara, CA, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Thomson
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA. Electronic address: mpschwartz@wisc.edu.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schwartz
authors.affiliation: Department of Biomedical Engineering, University of Wisconsin-Madison, WI, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, WI, USA. Electronic address: wlmurphy@wisc.edu.
authors.forename: William L
authors.initials: WL
authors.lastname: Murphy
mesh_terms: D001808:Blood Vessels / Q000187:drug effects / Q000502:physiology*; D002196:Capillaries / Q000187:drug effects / Q000502:physiology; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020100:Hydrogels / Q000494:pharmacology*; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D020100:Hydrogels
keywords: 3D culture; Biomaterials; Blood Vessel; Microfluidic; Thiolene; Tissue Engineering