title: Murine and human pluripotent stem cell-derived cardiac bodies form contractile myocardial tissue in vitro.
abstract: OBJECTIVE
  We explored the use of highly purified murine and human pluripotent stem cell (PSC)-derived cardiomyocytes (CMs) to generate functional bioartificial cardiac tissue (BCT) and investigated the role of fibroblasts, ascorbic acid (AA), and mechanical stimuli on tissue formation, maturation, and functionality.
  
  
  RESULTS
  Murine and human embryonic/induced PSC-derived CMs were genetically enriched to generate three-dimensional CM aggregates, termed cardiac bodies (CBs). Addressing the critical limitation of major CM loss after single-cell dissociation, non-dissociated CBs were used for BCT generation, which resulted in a structurally and functionally homogenous syncytium. Continuous in situ characterization of BCTs, for 21 days, revealed that three critical factors cooperatively improve BCT formation and function: both (i) addition of fibroblasts and (ii) ascorbic acid supplementation support extracellular matrix remodelling and CB fusion, and (iii) increasing static stretch supports sarcomere alignment and CM coupling. All factors together considerably enhanced the contractility of murine and human BCTs, leading to a so far unparalleled active tension of 4.4 mN/mm(2) in human BCTs using optimized conditions. Finally, advanced protocols were implemented for the generation of human PSC-derived cardiac tissue using a defined animal-free matrix composition.
  
  
  CONCLUSIONS
  BCT with contractile forces comparable with native myocardium can be generated from enriched, PSC-derived CMs, based on a novel concept of tissue formation from non-dissociated cardiac cell aggregates. In combination with the successful generation of tissue using a defined animal-free matrix, this represents a major step towards clinical applicability of stem cell-based heart tissue for myocardial repair.
authors.affiliation: Leibniz Research Laboratories for Biotechnology and Artificial Organs, Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Cluster of Excellence REBIRTH, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: George
authors.initials: G
authors.lastname: Kensah
authors.forename: Angelica
authors.initials: A
authors.lastname: Roa Lara
authors.forename: Julia
authors.initials: J
authors.lastname: Dahlmann
authors.forename: Robert
authors.initials: R
authors.lastname: Zweigerdt
authors.forename: Kristin
authors.initials: K
authors.lastname: Schwanke
authors.forename: Jan
authors.initials: J
authors.lastname: Hegermann
authors.forename: David
authors.initials: D
authors.lastname: Skvorc
authors.forename: Anke
authors.initials: A
authors.lastname: Gawol
authors.forename: Azadeh
authors.initials: A
authors.lastname: Azizian
authors.forename: Stefan
authors.initials: S
authors.lastname: Wagner
authors.forename: Lars S
authors.initials: LS
authors.lastname: Maier
authors.forename: Andreas
authors.initials: A
authors.lastname: Krause
authors.forename: Gerald
authors.initials: G
authors.lastname: Dräger
authors.forename: Matthias
authors.initials: M
authors.lastname: Ochs
authors.forename: Axel
authors.initials: A
authors.lastname: Haverich
authors.forename: Ina
authors.initials: I
authors.lastname: Gruh
authors.forename: Ulrich
authors.initials: U
authors.lastname: Martin
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001705:Bioprosthesis; D018929:Cell Culture Techniques / Q000379:methods; D049108:Cell Enlargement; D002460:Cell Line; D015870:Gene Expression; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000502:physiology; D051379:Mice; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000166:cytology*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000502:physiology; D012518:Sarcomeres / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods*; D014815:Vitamins / Q000494:pharmacology
chemical_list: D014815:Vitamins; D001205:Ascorbic Acid