Perspectives on carbon nanotube-mediated adverse immune effects

Carbon nanotubes are entities of different morphology and aspect ratios with anisotropic character. Due to their unique electronic, photonic, mechanical and chemical properties, carbon nanotubes are receiving increasing attention in nanomedicine research where examples include site-specific drug and nucleic acid delivery, photodynamic therapy and photoacoustic molecular imaging. The interaction of carbon nanotubes with the immune system, which plays a key role in the recognition and elimination of foreign materials, and consequential responses, is of central importance for the proposed successful biomedical applications of nanotubes. Research in this avenue, however, is scant and the limited available data are rather contradictory. In this progress article we have collected some of the most important experimental results obtained thus far on carbon nanotube-mediated immune toxicity with an emphasis on cardiovascular exposure, including activation of the complement system, macrophage recognition and clearance, and overall effects on the functionality of different immune cells. Mapping these immune-related risks as well as understanding their molecular mechanisms is a crucial step in the development of any carbon nanotube-containing nanopharmaceuticals.