Fibrogenic and immunotoxic responses to carbon nanotubes

Abstract

Carbon nanotubes (CNTs) are a major product of the emerging nanotechnology industry that have numerous applications. Human exposure to CNTs is inevitable as they will be manufactured and incorporated into consumer products. CNTs represent a widely varying class of nanomaterials that vary due to numbers of concentric walls (single versus multiple) and manufacturing process that result in variable rigidity and metal catalyst content. Moreover, post-synthesis functionalization to enhance the properties of CNTs will create a vast array of new nanomaterials that have unknown effects on biological systems. Toxicologists have been proactive in investigating the potential adverse effects of CNTs, and an overwhelming body of evidence shows that fibrosis is a common outcome of pulmonary exposure in rodents. CNTs also have adverse effects on the immune system, including impaired macrophage function and exacerbation of preexisting lung inflammatory diseases. In addition, CNTs may cause systemic immune suppression. A major issue is the potential carcinogenic effects of CNTs, particularly with regards to mesothelioma. The overall goal is to predict and prevent human disease that could occur from CNT exposure.