The interaction between cells and carbon nanotubes (CNT) is a critical issue that will determine any future biological application of such structures. In this communication we will show that various types of functionalized-carbon nanotubes (f-CNT) exhibit a capacity to be uptaken by a wide range of cells (prokaryotic and eukaryotic) and can intracellularly traffick through different cellular barriers([1, 2]). The mechanism by which f-CNT are able to cross cell membranes and deliver their cargo will also be discussed. Energy-independent mechanisms are explained based on the cylindrical shape and high aspect ratio of f-CNT that can allow their penetration through the plasma membrane, similar to a 'nanosyringe'([3]).
