title: Stromal Cells in Dense Collagen Promote Cardiomyocyte and Microvascular Patterning in Engineered Human Heart Tissue.
abstract: Cardiac tissue engineering is a strategy to replace damaged contractile tissue and model cardiac diseases to discover therapies. Current cardiac and vascular engineering approaches independently create aligned contractile tissue or perfusable vasculature, but a combined vascularized cardiac tissue remains to be achieved. Here, we sought to incorporate a patterned microvasculature into engineered heart tissue, which balances the competing demands from cardiomyocytes to contract the matrix versus the vascular lumens that need structural support. Low-density collagen hydrogels (1.25 mg/mL) permit human embryonic stem cell-derived cardiomyocytes (hESC-CMs) to form a dense contractile tissue but cannot support a patterned microvasculature. Conversely, high collagen concentrations (density ≥6 mg/mL) support a patterned microvasculature, but the hESC-CMs lack cell-cell contact, limiting their electrical communication, structural maturation, and tissue-level contractile function. When cocultured with matrix remodeling stromal cells, however, hESC-CMs structurally mature and form anisotropic constructs in high-density collagen. Remodeling requires the stromal cells to be in proximity with hESC-CMs. In addition, cocultured cardiac constructs in dense collagen generate measurable active contractions (on the order of 0.1 mN/mm(2)) and can be paced up to 2 Hz. Patterned microvascular networks in these high-density cocultured cardiac constructs remain patent through 2 weeks of culture, and hESC-CMs show electrical synchronization. The ability to maintain microstructural control within engineered heart tissue enables generation of more complex features, such as cellular alignment and a vasculature. Successful incorporation of these features paves the way for the use of large scale engineered tissues for myocardial regeneration and cardiac disease modeling.
authors.affiliation: 1 Department of Bioengineering, University of Washington , Seattle, Washington.|2 Center for Cardiovascular Biology, University of Washington , Seattle, Washington.|3 Institute for Stem Cell and Regenerative Medicine, University of Washington , Seattle, Washington.
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Roberts
authors.affiliation: 1 Department of Bioengineering, University of Washington , Seattle, Washington.
authors.forename: Dominic
authors.initials: D
authors.lastname: Tran
authors.affiliation: 2 Center for Cardiovascular Biology, University of Washington , Seattle, Washington.|3 Institute for Stem Cell and Regenerative Medicine, University of Washington , Seattle, Washington.|4 Department of Pathology, University of Washington , Seattle, Washington.
authors.forename: Kareen L K
authors.initials: KL
authors.lastname: Coulombe
authors.affiliation: 1 Department of Bioengineering, University of Washington , Seattle, Washington.|2 Center for Cardiovascular Biology, University of Washington , Seattle, Washington.|3 Institute for Stem Cell and Regenerative Medicine, University of Washington , Seattle, Washington.
authors.forename: Maria
authors.initials: M
authors.lastname: Razumova
authors.affiliation: 1 Department of Bioengineering, University of Washington , Seattle, Washington.|2 Center for Cardiovascular Biology, University of Washington , Seattle, Washington.|3 Institute for Stem Cell and Regenerative Medicine, University of Washington , Seattle, Washington.
authors.forename: Michael
authors.initials: M
authors.lastname: Regnier
authors.affiliation: 1 Department of Bioengineering, University of Washington , Seattle, Washington.|2 Center for Cardiovascular Biology, University of Washington , Seattle, Washington.|3 Institute for Stem Cell and Regenerative Medicine, University of Washington , Seattle, Washington.|4 Department of Pathology, University of Washington , Seattle, Washington.|5 Department of Medicine/Cardiology, University of Washington , Seattle, Washington.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Murry
authors.affiliation: 1 Department of Bioengineering, University of Washington , Seattle, Washington.|2 Center for Cardiovascular Biology, University of Washington , Seattle, Washington.|3 Institute for Stem Cell and Regenerative Medicine, University of Washington , Seattle, Washington.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D018920:Coculture Techniques; D003094:Collagen / Q000494:pharmacology*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D000066449:Human Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D055806:Microvessels / Q000187:drug effects / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D003094:Collagen