Cellular uptake enhancement of polyamidoamine dendrimer modified single walled carbon nanotubes

Carbon nanotubes represent a new class of gene transporters potentially useful for future in vitro and in vivo gene delivery applications. The aim of this study was to modify the surfaces of carbon nanotubes (CNTs) with polyamidoamine dendrimer (PAMAM) in order to reduce the cytotoxicity and enhance the cellular uptake of the nanoparticles. In this study, we have prepared and characterized the PAMAM dendrimer coated CNTs. We have investigated the effect of cellular uptake of uncoated and dendrimer coated CNT on cell adhesion/viability, cytotoxicity, and morphology of human breast cancer MCF-7 cells. Cell cytotoxicity/adhesion studies of CNTs on MCF-7 cells showed that the CNTs are a little toxic. On the other hand, dendrimer coated CNTs were found to be non-toxic. Transmission electron microscopy results indicated that the dendrimer coated CNTs were internalized into cells via different mechanisms, thereby suggesting that the particle endocytosis behaviour is dependent on the surface characteristics of the CNTs. This phenomena has potential application in further research to better design transfection reagents that will increase the efficiency of cancer therapy.