Letter pubs.acs.org/NanoLett
Carbon Nanotubes Promote Growth and Spontaneous Electrical Activity in Cultured Cardiac Myocytes Valentina Martinelli,†,▽ Giada Cellot,‡,∥,▽ Francesca Maria Toma,§ Carlin S. Long,⊥ John H. Caldwell,# Lorena Zentilin,† Mauro Giacca,† Antonio Turco,§ Maurizio Prato,*,§ Laura Ballerini,‡ and Luisa Mestroni*,⊥ †
International Centre for Genetic Engineering and Biotechnology, Trieste, Italy Life Science Department, B.R.A.I.N. and §Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste, Italy ∥ Department of Neurobiology, International School for Advanced Studies (SISSA), Trieste, Italy ⊥ University of Colorado Cardiovascular Institute and #Department of Cell and Developmental Biology, University of Colorado Denver, Aurora, Colorado 80045, United States ‡
S Supporting Information *
ABSTRACT: Nanoscale manipulations of the extracellular microenvironment are increasingly attracting attention in tissue engineering. Here, combining microscopy, biological, and single-cell electrophysiological methodologies, we demonstrate that neonatal rat ventricular myocytes cultured on substrates of multiwall carbon nanotubes interact with carbon nanotubes by forming tight contacts and show increased viability and proliferation. Furthermore, we observed changes in the electrophysiological properties of cardiomyocytes, suggesting that carbon nanotubes are able to promote cardiomyocyte maturation.
KEYWORDS: Carbon nanotubes, cardiac myocytes, tissue engineering, cardiomyocyte electrophysiology
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systems able to govern cell-specific behaviors in cultured neuronal networks.12−17 The potential impact of interfacing carbon nanotubes with excitable cells prompted us to investigate their ability to interface with cardiac myocytes, highly specialized, terminally differentiated cells with unique biophysical, electro-mechanical and ion channel properties. We hypothesized that cardiac myocytes interacting with carbon nanotubes may enhance their function and electrical properties. In this work, we report for the first time the impact of carbon nanotube platforms on cellular viability, proliferative capacity, maturation, and electrophysiological properties of cultured neonatal cardiac myocytes. Our results hold tremendous potential for a variety of novel therapeutic applications in human heart diseases. To develop carbon nanotube scaffolds, a solution of functionalized multiwall carbon nanotubes (MWCNTs) was deposited onto glass coverslips and subsequently dried. Prior to cell seeding, carbon nanotube-coated glass coverslips were annealed producing pristine (defunctionalized) MWCNTs (Supplemental Figure 1). Thermogravimetric analysis (TGA)
ngoing efforts in regenerative medicine require the development of synthetic extracellular scaffolds able to provide unique microenvironments to tissue-specific cell types.1−3 Micro- and nanoscale techniques employed to recreate interactions between cells and tissue-engineering scaffolds offer great promise in the fabrication of biological tissue constructs. These interactions are widely accepted as being essential to promote tissue development, to maintain tissue function, and to generate tissue repairing processes.4 Thus, exploiting physical and chemical features at the nanoscale may improve next generation of transplantable cell-enriched devices for tissue implants. Carbon nanotubes have been at the forefront of nanotechnology due to their unique electrical, mechanical, and thermal features, which allow the development of a variety of miniaturized devices with remarkable properties.3,5−7 They are cylindrically shaped nanostructures of carbon with a diameter ranging from 1 to 100 nm with high electrical conductivity.8,9 They can be functionalized by attaching chemical compounds and used as vectors for drug delivery10 or, once assembled into scaffolds of small fibers, used as structural supports for tissue engineering.11 More recently, carbon nanotubes have attracted tremendous attention for the development of nano−bio hybrid © 2012 American Chemical Society
Received: November 17, 2011 Revised: February 27, 2012 Published: March 20, 2012 1831
dx.doi.org/10.1021/nl204064s | Nano Lett. 2012, 12, 1831−1838
Nano Letters
Letter
Figure 1. Characterization of MWCNT substrates and ultrastructural interaction between MWCNTs and cultured cardiac myocytes. TGA under nitrogen of functionalized MWCNTs (dash line), their relative defunctionalization after annealing at 350 °C in inert atmosphere (solid line), and metal content (
