title: Construction of multi-layered cardiomyocyte sheets using magnetite nanoparticles and magnetic force.
abstract: Heart tissue engineering requires construction of three-dimensional (3-D) tissues composed of cardiomyocytes (CMs) that are tightly connected to each other. The aim of this study was to construct "scaffold-less" multi-layered 3-D CM sheets using magnetic force-based tissue engineering (Mag-TE) and to evaluate the cell-to-cell functional connections within the CM sheets. Original magnetite cationic liposomes (MCLs) with a positive surface charge (which facilitate adsorption to the target cell surface) were taken up by CMs that were isolated from 2-day-old Wistar rats. When MCLs were added to the medium of CMs at magnetite concentrations of 25, 50, and 100 pg per cell, subsequent measurements showed that 7.2, 13.2, and 27.3 pg of magnetite were taken up per cell, respectively, after 4 h incubation at 37 degrees C. Further, no toxicity was observed after a 24 h incubation period. Using magnetically labeled CMs (magnetite concentration, 100 pg/cell), multi-layered CM sheets were constructed. Immunofluorescent staining of connexin43 demonstrated the presence of gap junctions within the CM sheets that were constructed by Mag-TE. Moreover, electrical connections within the CM sheets constructed by Mag-TE were confirmed using extracellular potential mapping. These results indicate that Mag-TE is a viable methodology for heart tissue engineering.
authors.affiliation: Department of Biotechnology, School of Engineering, Nagoya University, Nagoya, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Shimizu
authors.forename: Akira
authors.initials: A
authors.lastname: Ito
authors.forename: Jong-Kook
authors.initials: JK
authors.lastname: Lee
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Yoshida
authors.forename: Keiko
authors.initials: K
authors.lastname: Miwa
authors.forename: Hisaaki
authors.initials: H
authors.lastname: Ishiguro
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Numaguchi
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Murohara
authors.forename: Itsuo
authors.initials: I
authors.lastname: Kodama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Honda
mesh_terms: D000818:Animals; D052203:Ferrosoferric Oxide; D008280:Magnetics; D053768:Metal Nanoparticles; D032383:Myocytes, Cardiac / Q000166:cytology*; D009924:Organ Culture Techniques / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D052203:Ferrosoferric Oxide