Graphene nanoribbons are internalized by human primary immune cell subpopulations maintaining a safety profile: A high-dimensional pilot study by single-cell mass cytometry

•Graphene nanoribbons of different sizes have been functionalized with mass cytometry trackable 115Indium through a straightforward method.•Graphene nanoribbons showed high biocompatibility on peripheral blood mononuclear cells.•Mass cytometry analysis revealed the capability of graphene nanoribbons to simulate myeloid dendritic cells and classical monocytes.