Stable, concentrated, biocompatible, and defect-free graphene dispersions with positive charge - Shin, Yuyoung (University of Manchester. Department of Chemistry) ; Vranic, Sandra (University of Manchester. Nanomedicine Lab) ; Just-Baringo, Xavier (University of Manchester. Department of Chemistry) ; Gali, Sai Manoj (Institut Català de Nanociència i Nanotecnologia) ; Kisby, Thomas (University of Manchester. National Graphene Institute) ; Chen, Yingxian (University of Manchester. Nanomedicine Lab) ; Gkoutzidou, Alexandra (University of Manchester. Department of Materials) ; Prestat, Eric (SciTech Daresbury Campus. SuperSTEM Laboratory) ; Beljonne, David (Institut Català de Nanociència i Nanotecnologia) ; Larrosa, Igor (University of Manchester. Department of Chemistry) ; Kostarelos, Kostas (Institut Català de Nanociència i Nanotecnologia) ; Casiraghi, Cinzia (University of Manchester. Department of Chemistry)