doi:10.3390/nano11113017engD’amora M.Camisasca A.Arenal R.Giordani S.In vitro and in vivo biocompatibility of boron/nitrogen co-doped carbon nano-onionsART-2021-126825Boron/nitrogen, co-doped, carbon nano-onions (BN-CNOs) have recently shown great promise as catalysts for the oxygen reduction reaction, due to the improved electronic properties imparted by the dopant atoms; however, the interactions of BN-CNOs with biological systems have not yet been explored. In this study, we examined the toxicological profiles of BN-CNOs and oxidized BN-CNOs (oxi-BN-CNOs) in vitro in both healthy and cancer cell lines, as well as on the embryonic stages of zebrafish (Danio rerio) in vivo. The cell viabilities of both cell lines cells were not affected after treatment with different concentrations of both doped CNO derivatives. On the other hand, the analysis of BN-CNOs and oxidized BN-CNO interactions with zebrafish embryos did not report any kind of perturbations, in agreement with the in vitro results. Our results show that both doped CNO derivatives possess a high biocompatibility and biosafety in cells and more complex systems. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.2021http://zaguan.unizar.es/record/11959210.3390/nano11113017http://zaguan.unizar.es/record/119592oai:zaguan.unizar.es:119592info:eu-repo/grantAgreement/EC/H2020/823717/EU/Enabling Science and Technology through European Electron Microscopy/ESTEEM3This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 823717-ESTEEM3Nanomaterials 11, 11 (2021), 3017 [13 pp]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess