Investigating the cellular response to nanofibrous materials by use of a multi-walled carbon nanotube model

One motivation for synthesizing nanofibrous materials is the desire to mimic interactions between cells and the natural extracellular matrix. The cellular response to nanofibre assemblies of differing length-scales and densities of nanofibres is of direct interest; in this study, we investigate the response of human lung epithelial cells (A549), osteoblast-like cells (MG63), and primary osteoblast cells to a model nanofibre system over a seven-day period. A low-density array of multi-walled carbon nanotubes (MWCNTs) (dia. 35 nm) provides a non-degradable, stiff, nanofibrous surface for cell culture investigation. We find that cells attach and survive on MWCNTs, although proliferation is not as rapid as on flat control substrates. Immunofluorescent vinculin staining revealed that small point-contacts are produced by cells attached to MWCNTs. Larger focal adhesions, as typically found in two-dimensional surface culture, were not seen for cells attached to the nanotube substrates. The MWCNT arrays provide a simple, yet effective, model system with which to develop a better understanding of cell responses to nanofibrous constructs which are relevant to tissue engineering and regenerative medicine. © 2006, Taylor & Francis Group, LLC.