{"id":53,"date":"2008-10-29T09:53:27","date_gmt":"2008-10-29T17:53:27","guid":{"rendered":"http:\/\/blogs.edf.org\/nanotechnology\/2008\/10\/29\/a-length-b-metals-c-oxygen-d-surface-e-all-of-the-above\/"},"modified":"2024-02-12T11:00:22","modified_gmt":"2024-02-12T16:00:22","slug":"a-length-b-metals-c-oxygen-d-surface-e-all-of-the-above","status":"publish","type":"post","link":"https:\/\/blogs.edf.org\/health\/2008\/10\/29\/a-length-b-metals-c-oxygen-d-surface-e-all-of-the-above\/","title":{"rendered":"A. Length, B. Metals, C. Oxygen, D. Surface, or E. All of the Above?"},"content":{"rendered":"

<\/em>Cal Baier-Anderson, Ph.D.<\/em>, is a Health Scientist.<\/em><\/p>\n

The manufacture of carbon nanotubes (CNTs) is a very complicated business.\u00a0 Different production processes leave behind different kinds of metal catalysts, which yield differences in physical and chemical – as well as toxicological – properties of the CNTs.\u00a0 <\/p>\n

Removal of metals can alter the surface and other properties. \u00a0These properties affect both the performance and the potential toxicity or other biological activity of the CNTs.<\/p>\n

While a given material’s intended use often dictates the means of manufacturing and subsequent processing, the challenge is to integrate safety considerations up front rather than as an afterthought to be considered only at the end of the design process.\u00a0 But to do so, we need to develop a much better understanding of how properties and structural features correlate with safety risks.<\/p>\n

A pair of interesting papers just published in the journal Chemical Research in Toxicology<\/a> examines the relationship between these physicochemical properties and potential hazard.<\/p>\n

In these papers, a group of European researchers created and characterized five kinds of CNTs, and then explored the question of what features are the most important in determining hazard: \u00a0residual metals, the presence of oxygenated functional groups, or surface defects.\u00a0 As measures of hazard, the authors examined the ability of each CNT to scavenge free radicals (a protective function since free radicals can damage cell membranes), cause lung inflammation in rats, and damage DNA.\u00a0 The results are intriguing:<\/p>\n