Biological Applications of Carbon Nanotubes

Adoptive T cell transfer, involving the ex vivo expansion of T lymphocytes, is a viable therapeutic approach for both infectious diseases and cancer, with demonstrated efficacy in treating melanoma, Epstein-Barr virus, and HIV-related infections. However, T cell transfer by clonal expansion is not clinically feasible as it does not consistently generate therapeutic quantities of T cells. Efforts to develop a reproducible “off-the-shelf” means of stimulating and expanding T cells in vitro have focused on beadbased systems. This novel approach involves single walled carbon nanotubes (SWNT) coupled to antiCD3 antibodies, a known stimulant for T-cell proliferation. SWNTs have a much higher surface area to volume ratio than previous artificial antigen-presenting cells (aAPCs), which facilitates the high density clusters of T cell antigen receptors that are critical for T-cell activation. Anti-CD3 antibodies adsorbed onto SWNT bundles activate T-cells at antibody concentrations at least an order of magnitude less than antibody alone. Furthermore, similar activation is not achieved with other high surface area materials such as activated carbon, polystyrene nanoparticles, and buckyballs. This novel method thus utilizes the unique properties of SWNTs for enhanced stimuli presentation.