Behaviors of NIH-3T3 fibroblasts on graphene/carbon nanotubes: proliferation, focal adhesion, and gene transfection studies.

Carbon-based materials, including graphene and carbon nanotubes, have been considered attractive candidates for biomedical applications such as scaffolds in tissue engineering, substrates for stem cell differentiation, and components of implant devices. Despite the potential biomedical applications of these materials, only limited information is available regarding the cellular events, including cell viability, adhesion, and spreading, that occur when mammalian cells interface with carbon-based nanomaterials. Here, we report behaviors of mammalian cells, specifically NIH-3T3 fibroblast cells, grown on supported thin films of graphene and carbon nanotubes to investigate biocompatibility of the artificial surface. Proliferation assay, cell shape analysis, focal adhesion study, and quantitative measurements of cell adhesion-related gene expression levels by RT-PCR reveal that the fibroblast cells grow well, with different numbers and sizes of focal adhesions, on graphene- and carbon nanotube-coated substrates. Interestingly, the gene transfection efficiency of cells grown on the substrates was improved up to 250% that of cells grown on a cover glass. The present study suggests that these nanomaterials hold high potential for bioapplications showing high biocompatibility, especially as surface coating materials for implants, without inducing notable deleterious effects while enhancing some cellular functions (i.e., gene transfection and expression).