Nanotoxicity assessment toward the applications of carbon nanotubes as a small biomolecule carrier in drug delivery systems

Carbon Nanotube (CNT) materials has superior properties in electric current carrying capacity, thermal conductivity, and thermal stability. Due to their structure with high aspect ratio, they have structural unusual toxicity and complicate safety issue in a target tissue. In optimized quantities with limited functionality, special type of CNT assembly such as "buckyball" can be used as a potential drug carrier of bioactive molecules and display with increased circulating time and acceptable functionality. We analyzed cytoxicity and inflammatory response following exposure of CNTs. Slow damaging effects of CNT to epidermis and dermis of rat skin was shown using micro-imaging. Physiological perturbation of lung barrier function was observed by measuring transepithelial electrical resistance (TER) during the exposure of different concentrations of CNTs to human lung epithelial cell monolayers in the presence of fibroblast-embedded collagen. The mechanisms of CNTs' toxicity may be closely related to their structure, functional group, and surface charge on the molecule. Further studies are required to probe the mechanisms of cytotoxic and inflammatory responses. We also established the nanoscale toxicity of fullerenes of CNTs.