title: Cardiac muscle tissue engineering: toward an in vitro model for electrophysiological studies.
abstract: The objective of this study was to establish a three-dimensional (3-D) in vitro model system of cardiac muscle for electrophysiological studies. Primary neonatal rat ventricular cells containing lower or higher fractions of cardiac myocytes were cultured on polymeric scaffolds in bioreactors to form regular or enriched cardiac muscle constructs, respectively. After 1 wk, all constructs contained a peripheral tissue-like region (50-70 micrometer thick) in which differentiated cardiac myocytes were organized in multiple layers in a 3-D configuration. Indexes of cell size (protein/DNA) and metabolic activity (tetrazolium conversion/DNA) were similar for constructs and neonatal rat ventricles. Electrophysiological studies conducted using a linear array of extracellular electrodes showed that the peripheral region of constructs exhibited relatively homogeneous electrical properties and sustained macroscopically continuous impulse propagation on a centimeter-size scale. Electrophysiological properties of enriched constructs were superior to those of regular constructs but inferior to those of native ventricles. These results demonstrate that 3-D cardiac muscle constructs can be engineered with cardiac-specific structural and electrophysiological properties and used for in vitro impulse propagation studies.
authors.affiliation: Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139, Massachusetts, USA.
authors.forename: N
authors.initials: N
authors.lastname: Bursac
authors.forename: M
authors.initials: M
authors.lastname: Papadaki
authors.forename: R J
authors.initials: RJ
authors.lastname: Cohen
authors.forename: F J
authors.initials: FJ
authors.lastname: Schoen
authors.forename: S R
authors.initials: SR
authors.lastname: Eisenberg
authors.forename: R
authors.initials: R
authors.lastname: Carrier
authors.forename: G
authors.initials: G
authors.lastname: Vunjak-Novakovic
authors.forename: L E
authors.initials: LE
authors.lastname: Freed
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001673:Biodegradation, Environmental; D001698:Biomedical Engineering / Q000295:instrumentation / Q000379:methods; D046508:Culture Techniques; D004594:Electrophysiology; D006352:Heart Ventricles; D006652:Histological Techniques / Q000295:instrumentation; D010210:Papillary Muscles / Q000166:cytology / Q000502:physiology*; D011108:Polymers; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D011108:Polymers