title: A New In Vitro Co-Culture Model Using Magnetic Force-Based Nanotechnology.
abstract: Skeletal myoblast (SkMB) transplantation has been conducted as a therapeutic strategy for severe heart failure. However, arrhythmogenicity following transplantation remains unsolved. We developed an in vitro model of myoblast transplantation with "patterned" or "randomly-mixed" co-culture of SkMBs and cardiomyocytes enabling subsequent electrophysiological, and arrhythmogenic evaluation. SkMBs were magnetically labeled with magnetite nanoparticles and co-cultured with neonatal rat ventricular myocytes (NRVMs) on multi-electrode arrays. SkMBs were patterned by a magnet beneath the arrays. Excitation synchronicity was evaluated by Ca(2+) imaging using a gene-encoded Ca(2+) indicator, G-CaMP2. In the monoculture of NRVMs (control), conduction was well-organized. In the randomly-mixed co-culture of NRVMs and SkMBs (random group), there was inhomogeneous conduction from multiple origins. In the "patterned" co-culture where an en bloc SKMB-layer was inserted into the NRVM-layer, excitation homogenously propagated although conduction was distorted by the SkMB-area. The 4-mm distance conduction time (CT) in the random group was significantly longer (197 ± 126 ms) than in control (17 ± 3 ms). In the patterned group, CT through NRVM-area did not change (25 ± 3 ms), although CT through the SkMB-area was significantly longer (132 ± 77 ms). The intervals between spontaneous excitation varied beat-to-beat in the random group, while regular beating was recorded in the control and patterned groups. Synchronized Ca(2+) transients of NRVMs were observed in the patterned group, whereas those in the random group were asynchronous. Patterned alignment of SkMBs is feasible with magnetic nanoparticles. Using the novel in vitro model mimicking cell transplantation, it may become possible to predict arrhythmogenicity due to heterogenous cell transplantation. J. Cell. Physiol. 231: 2249-2256, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathophysiology, Oita University School of Medicine, Oita, Japan.|Department of Cardiovascular Research, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.|Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takanari
authors.affiliation: Department of Cardiovascular Research, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.|Department of Cardiovascular Regenerative Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Miwa
authors.affiliation: Department of Cardiovascular Research, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.|Department of Cardiothoracic Surgery, Graduate School of Medicine, Nagoya University, Nagoya, Japan.|Department of Cardiovascular Surgery, Central South University The Second Xiangya Hospital, Changsha, China.
authors.forename: XianMing
authors.initials: X
authors.lastname: Fu
authors.affiliation: Saitama University Brain Science Institute, Saitama, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Nakai
authors.affiliation: Department of Chemical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ito
authors.affiliation: Department of Biotechnology, School of Engineering, Nagoya University, Nagoya, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Ino
authors.affiliation: Department of Biotechnology, School of Engineering, Nagoya University, Nagoya, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Honda
authors.affiliation: Department of Mechanical Engineering, Ritsumeikan University, Kusatsu, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Tonomura
authors.affiliation: Department of Mechanical Engineering, Ritsumeikan University, Kusatsu, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Konishi
authors.affiliation: Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.|Experimental Cardiology Group, Center for Heart Failure Research, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Tobias
authors.initials: T
authors.lastname: Opthof
authors.affiliation: Division of Heart and Lungs, Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Marcel Ag
authors.initials: MA
authors.lastname: van der Heyden
authors.affiliation: Nagoya University, Nagoya, Japan.
authors.forename: Itsuo
authors.initials: I
authors.lastname: Kodama
authors.affiliation: Department of Cardiovascular Regenerative Medicine, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Jong-Kook
authors.initials: JK
authors.lastname: Lee
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D002478:Cells, Cultured; D018920:Coculture Techniques; D006352:Heart Ventricles / Q000166:cytology*; D058185:Magnetite Nanoparticles / Q000008:administration & dosage*; D032448:Myoblasts, Skeletal / Q000166:cytology*; D009203:Myocardial Infarction / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000166:cytology*; D036103:Nanotechnology / Q000379:methods; D017208:Rats, Wistar
chemical_list: D058185:Magnetite Nanoparticles