The many applications of graphene nanomaterials also include those in the field of medicine, from cancer therapies to tissue engineering and gene transfer. The main barrier that tools manufactured with these materials will have to overcome is the reaction of the immune system. Now European researchers have analyzed how our defences act in the presence of graphene oxide, the oxidised form of graphene.
Researchers have analysed how graphene oxide affects various cell types of our immune system. / Credit: G-IMMUNOMICS
Graphene oxide is a carbon material with unique properties that could be used in medicine as a novel diagnostic and therapeutic tool. But before taking this step, an essential requirement for scientists is to properly understand how it interacts with the immune cells that protect our organism from intruders.
Researchers from the University of Sassari (Italy), the CNRS in Strasbourg, the University of Rome Tor Vergata and other European centres have developed experimental setting to characterize the complex interactions between graphene oxide and fifteen cell types of our immune system, including T lymphocytes, leukocytes, monocytes, NK cells and dendritic cells.
Graphene oxide could be used in medicine as a novel diagnostic and therapeutic tool, but the scientists have to understand first how it interacts with the immune cells
The data of this study, published in the Nature Communications, emphasise the importance of 'functionalising' graphene-based nanomaterials, adding functional groups, such as the amino group, to their surface in order to make them more compatible with human immune cells.
"In particular, we have used single cell mass cytometry to analyze how graphene oxide affects these cells and if changes occur when it is 'functionalised', that is, when it conjugated to other molecules," explains Lucia Gemma Delogu, one of the authors.
Single cell mass cytometry allows to detect several immune cell subpopulations andspecific proteins of the cells, both on its surface and in its interior, with great precision. With this method, researchers have been able to measure more than thirty cell markers.
"Thus we have found that graphene functionalised with amino groups increases its biocompatibility as compared to 'normal' graphene oxide," Delogu points out. "Moreover, we were able to identify specific stimuli of functionalised graphene in two cell types: monocytes and dendritic cells."
A deep transcriptome analysis has also been used to see how the expression of the genes of immune cells is modified. The results confirm that amino groups reduce the disturbances caused by graphene oxide in the cellular metabolism, increasing the biocompatibility of this material.
Biomedical platforms based on graphene
"In addition, a positive specific impact of graphene oxide on certain immune cells can serve as a starting point for developing biomedical platforms based on this nanometer-scale material, such as new immunotherapies, vaccine carriers and nano-adjuvants," says Delogu, who recalls that graphene nanomaterials have a 'facility' for being conjugated with drugs and other molecules on their surface, "improving the function of the drug and the specificity on the target of interest."
Graphene functionalised with amino groups increases its biocompatibility
The researcher insists that discovering the most suitable 'functionalisations' of graphene will be essential for advancing in these and other applications in medicine: cancer therapies, disease diagnosis tools, tissue engineering, transfer of genetic material, as well as in the combined area of biomedical images and neuroscience.
This study is part of the G-IMMUNOMICS project within the major European Graphene Flagship initiative. Using immunogenomic and protein data, it has the objective of enabling one to safely use graphene in medicine and in any other field, minimising its effects on health and the environment. Currently, its impact is analysed not only in human cells, but also in those of pigs, mice and the C.elegans worm.
Marco Orecchioni, Davide Bedognetti, Leon Newman, Claudia Fuoco, Filomena Spada, Wouter Hendrickx, Francesco M. Marincola, Francesco Sgarrella, Artur Filipe Rodrigues, Cécilia Ménard-Moyon, Gianni Cesareni, Kostas Kostarelos, Alberto Bianco & Lucia G Delogu. “Single-cell mass cytometry and transcriptome profiling reveal the impact of graphene on human immune cells”. Nature Communications 8: 1109, 2017. Doi:10.1038/s41467-017-01015-3.
SINC produces scientific news for the European project SCOPE, coordinated by FECYT and funded by the European Union through Horizon 2020, its funding program. The SCOPE mission is to communicate visionary research results of partnering projects in the framework of the Graphene Flagship and the Human Brain Project, as well as to enhance the FET Flagships partnering environment in the European Union.