Newswise — In a correspondence published recently in the journal Nature Nanotechnology, scientists from Penn State and 31 other universities and medical centers take issue with an article published in the same journal calling for the banning or restriction of carbon nanotubes in Europe.

In their rebuttal, the nanotube researchers say that restriction of the entire class of nanomaterial on the basis of safety is casting much too wide a net, that safety concerns of early biomedical experiments have been overcome recently – with better methods of functionalization of nanotube derived materials, and restrictions would limit scientific and medical progress unnecessarily.

According to Slava V. Rotkin, one of the Penn State cosigners along with Mauricio Terrones, “These materials have been used for intracell imaging, for example. Nanotubes are bright but very small. What people were doing in earlier studies was pushing a bunch of nanotubes into a cell in order to see them well. But that was too many – they clumped together and quickly killed the cell.”

Around fifteen years ago, Ming Zheng (NIST) and Anand Jagota (Lehigh University) found a way to wrap the nanotubes in artificial DNA. Artificial DNA allows researchers the ability to process nanotubes without clumping and separate them by electronic properties. These functionalized nanotubes were biocompatible and useful for biomedical applications. These could be applied, for instance, to treat kidney disease and investigate Parkinson’s disease. Rotkin and his co-workers Sabrina Jedlicka (Lehigh University) and Tetyana Ignatova (UNCG) applied individual DNA-wrapped tubes for mechanical stimulation of neural stem cells. In these papers (DOI: 10.1039/C7TB00766C and 10.1002/adbi.201800321), cells that uptake nanotubes were tracked for more than 3 weeks and survived well the experiment (see Fig.)

Carbon nanotubes could also be used to track viral outbreaks, improve the strength of building materials, for gene delivery, image-guided surgery and non-invasive disease monitoring.

“The opinion we are arguing with is from a group of risk and toxicology specialists, not necessarily reflecting all existing expertise of materials science, physics, chemistry and biology of nanotubes,” Rotkin says. “People, having a full grasp of the complexity of the topic, expressed their strong disagreement with conclusion that all nanotubes are bad, carcinogenic, deadly. What we emphasize is you have to know how to functionalize it for biomedical applications and how to use it in appropriate quantity. What we are trying to say is people should not put a ban on the propagation of knowledge without performing deep scientific analysis and providing very good reasons.”

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Nature Nanotechnology Mar-2020