title: Micro-arrayed human embryonic stem cells-derived cardiomyocytes for in vitro functional assay.
abstract: BACKGROUND
  The heart is one of the least regenerative organs in the body and any major insult can result in a significant loss of heart cells. The development of an in vitro-based cardiac tissue could be of paramount importance for many aspects of the cardiology research. In this context, we developed an in vitro assay based on human cardiomyocytes (hCMs) and ad hoc micro-technologies, suitable for several applications: from pharmacological analysis to physio-phatological studies on transplantable hCMs. We focused on the development of an assay able to analyze not only hCMs viability, but also their functionality.
  
  
  METHODS
  hCMs were cultured onto a poly-acrylamide hydrogel with tunable tissue-like mechanical properties and organized through micropatterning in a 20×20 array. Arrayed hCMs were characterized by immunofluorescence, GAP-FRAP analyses and live and dead assay. Their functionality was evaluated monitoring the excitation-contraction coupling.
  
  
  RESULTS
  Micropatterned hCMs maintained the expression of the major cardiac markers (cTnT, cTnI, Cx43, Nkx2.5, α-actinin) and functional properties. The spontaneous contraction frequency was (0.83±0.2) Hz, while exogenous electrical stimulation lead to an increase up to 2 Hz. As proof of concept that our device can be used for screening the effects of pathological conditions, hCMs were exposed to increasing levels of H(2)O(2). Remarkably, hCMs viability was not compromised with exposure to 0.1 mM H(2)O(2), but hCMs contractility was dramatically suppressed. As proof of concept, we also developed a microfluidic platform to selectively treat areas of the cell array, in the perspective of performing multi-parametric assay.
  
  
  CONCLUSIONS
  Such system could be a useful tool for testing the effects of multiple conditions on an in vitro cell model representative of human heart physiology, thus potentially helping the processes of therapy and drug development.
authors.affiliation: Industrial Engineering Department, University of Padova, Padova, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Serena
authors.forename: Elisa
authors.initials: E
authors.lastname: Cimetta
authors.forename: Susi
authors.initials: S
authors.lastname: Zatti
authors.forename: Tania
authors.initials: T
authors.lastname: Zaglia
authors.forename: Monica
authors.initials: M
authors.lastname: Zagallo
authors.forename: Gordon
authors.initials: G
authors.lastname: Keller
authors.forename: Nicola
authors.initials: N
authors.lastname: Elvassore
mesh_terms: D018929:Cell Culture Techniques; D002454:Cell Differentiation; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000166:cytology*; D020869:Gene Expression Profiling; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress / Q000235:genetics
chemical_list: D006861:Hydrogen Peroxide