ABSTRACT
Amid all the materials reported under the common umbrella of nanotechnology, carbon nanotubes (CNT) have attracted the attention of numerous scientists, due to the possibility of being applied in engineering, physics, chemistry, materials science and biology. The potential risk associated with CNTs includes the toxicity of eventual impurities in the samples, and the possibility, due to their small dimensions, that CNTs escape from the normal phagocytic defences and deposit into organ and tissues, with hazardous effects on the body. Accordingly, the tubular structure of CNTs provides a large and reactive surface area, which might render CNTs accountable for the observed cytotoxicity and thus unsuitable for biomedical applications. Functionalisation of CNTs, besides improving water dispersibility compared with their pristine counterparts, offers the advantage of incorporating biologically active moieties such as antibodies and drug molecules. Several methods adopted for the production of CNTs involve the use of metals as catalysts which, if present in high amount, enhance cytotoxicity.
