Due to their unique size, engineered nanomaterials (ENMs), or nanomaterials designed and produced by humans, offer a range of advantages. For example, in healthcare, they have the potential to help deliver medication to otherwise inaccessible areas of the body. In agriculture, they can help improve the efficient use of agrochemicals, while industry uses them as additives to enhance the strength and life of chemicals. “Because ENMs are difficult to detect in complex biological tissues and environments, we have little understanding about the safety risks they could pose,” says Eugenia Valsami-Jones, coordinator of the EU-funded NanoLabels project which was supported the Marie Skłodowska-Curie Actions programme. “Until we build enough confidence about where these materials go and what they do, especially after their intended use, the use of ENMs will remain limited.” One way researchers make ENMs more detectable is by adding a tracer, or label. Unfortunately, doing so can modify or change the ENMs and thus alter their environmental and biological behaviour. For this reason, tracers have been of limited use in terms of understanding nanosafety. To improve their usefulness, the NanoLabels project has developed innovative labelling techniques that could allow ENMs to be traced in their natural environment.
Creating a labelling strategy
Researchers at the University of Birmingham have spent the last decade working on using stable isotopes to label ENMs – an approach that has proved to be both efficient and highly sensitive at detecting ENMs in environmental-relevant concentrations. “The NanoLabels project builds on this work, creating a labelling strategy that can be adopted by industry to facilitate, for example, nanosafety assessments before ENMs enter the market,” explains Valsami-Jones, a professor of environmental nanoscience at the University of Birmingham. By exposing rice plants to different labelled nanoparticles, researchers were able to track the movement of nanoparticles within the plant and discover where they go and what they do. “For the first time, we used stable isotope labelling to track the translocation of a nanomaterial within plants,” notes Valsami-Jones. According to Valsami-Jones, the project demonstrated that physicochemical properties, such as size and morphology of the nanoparticles, are no different from the nanoparticles without isotope labelling. “This suggests that the labelling was a success and could be used with confidence in other tracing studies,” she adds.
A successful methodology
The NanoLabels methodology succeeded at detecting the uptake of ENMs in the environment, even at a very low concentration. “The labelling methodology we developed in this project, which has been subsequently published in ‘Nature Protocols’, has put our ‘stamp’ on this developing field of research,” says Valsami-Jones. “It will also play a big part in educating the next generation of nanoscientists in using isotope labelling techniques.” Another important outcome of the project is scalability. “We expect that the scaling-up of the synthesis of stable isotope labelled ENMs could be tested, modified and standardised. It has the potential to be used in such industrial applications as the authentication of materials,” Valsami-Jones explains. Project researchers are currently developing labelling for carbon-based nanomaterials, such as carbon nanotube, graphene and microplastics. “With carbon being the most common element in the environment, the tracing of carbon-based nanomaterials is extremely difficult – so watch this space,” concludes Valsami-Jones.
NanoLabels, engineered nanomaterials, nanomaterials, nanoscience, nanosafety, stable isotopes, nanoparticles