Posted: Oct 18, 2018
(Nanowerk News) Graphene has been hailed as the material of the future. As yet, however, little is known about whether and how graphene affects our health if it gets into the body. A team of researchers from Empa and the Adolphe Merkle Institute (AMI) in Fribourg have now conducted the first studies on a three-dimensional lung model to examine the behavior of graphene and graphene-like materials once they have been inhaled.
Tensile, tear-proof, highly elastic and electrically conductive: Graphene has a startling array of extraordinary properties, which enable revolutionary applications in a vast range of fields. It is not by chance that the EU launched the Graphene Flagship project, which enjoys one billion Euros in funding and is the largest European research initiative. As part of this enormous project, Empa also brings its expertise to the table, since potential health aspects and the impact on the human organism also play a key role within the scope of this pan-European graphene research.
These activities have now spawned an additional project funded by the Swiss National Science Foundation (SNSF), which was recently launched at Empa and AMI. It involves using a cellular 3D lung model, with the aid of which the researchers hope to find out what impact graphene and graphene-like materials might have on the human lung under conditions that are as realistic as possible.
No mean feat: After all, not all graphene is the same. Depending on the production method and processing, a vast range of forms and quality spectra of the material emerges, which in turn can trigger different responses in the lung.
The lung model at Adolphe Merkle Institute (AMI) in Fribourg (Image: AMI)
Conventional in vitro tests work with cell cultures from just one cell type – the newly established lung model, on the other hand, bears three different cell types, which simulate the conditions inside the lung, namely alveolar epithelial cells and two kinds of immune cells – macrophages and dendritic cells.
Another factor that has virtually been ignored in in vitro tests thus far is the contact with airborne graphene particles. Usually, cells are cultivated in a nutrient solution in a petri dish and exposed to materials, such as graphene, in this form.
In reality, however, i.e. at the lung barrier, it is an entirely different story. “The human organism typically comes into contact with graphene particles via respiration,” explains Tina Bürki from Empa’s Particles-Biology Interactions lab.
In other words, the particles are inhaled and touch the lung tissue directly. The new lung model is designed in such a way that the cells sit on a porous filter membrane at the air-liquid interface and the researchers spray graphene particles on the lung cells with the aid of a nebulizer in order to simulate the process in the body as closely as possible. The three-dimensional cell culture thus effectively “breathes in” graphene dust.
Three-dimensional cell cultures “inhale” particles
The research team headed by Peter Wick, Tina Bürki and Jing Wang from Empa and Barbara Rothen-Rutishauser and Barbara Drasler from AMI recently published their first results in the journal Carbon. Thanks to the 3D lung model, the researchers have succeeded in simulating the actual conditions at the blood-air barrier and the impact of graphene on the lung tissue as realistically as possible – without any tests on animals or humans. It is a cell model representing the lung alveoli.![lung model for graphene testing](https://www.nanowerk.com/nanotechnology-news2/id51291_1.jpg)