doi:10.1039/c7nr06020cengMarín-Barba, M.Gavilán, H.Gutiérrez, L.Lozano-Velasco, E.Rodríguez-Ramiro, I.Wheeler, G.N.Morris, C.J.Morales, M.P.Ruiz, A.Unravelling the mechanisms that determine the uptake and metabolism of magnetic single and multicore nanoparticles in a: Xenopus laevis modelART-2018-104184Multicore superparamagnetic nanoparticles have been proposed as ideal tools for some biomedical applications because of their high magnetic moment per particle, high specific surface area and long term colloidal stability. Through controlled aggregation and packing of magnetic cores it is possible to obtain not only single-core but also multicore and hollow spheres with internal voids. In this work, we compare toxicological properties of single and multicore nanoparticles. Both types of particles showed moderate in vitro toxicity (MTT assay) tested in Hep G2 (human hepatocellular carcinoma) and Caco-2 (human colorectal adenocarcinoma) cells. The influence of surface chemistry in their biological behavior was also studied after functionalization with O, O'-bis(2-aminoethyl) PEG (2000 Da). For the first time, these nanoparticles were evaluated in a Xenopus laevis model studying their whole organism toxicity and their impact upon iron metabolism. The degree of activation of the metabolic pathway depends on the size and surface charge of the nanoparticles which determine their uptake. The results also highlight the potential of Xenopus laevis model bridging the gap between in vitro cell-based assays and rodent models for toxicity assessment to develop effective nanoparticles for biomedical applications.2018http://zaguan.unizar.es/record/7876710.1039/c7nr06020chttp://zaguan.unizar.es/record/78767oai:zaguan.unizar.es:78767info:eu-repo/grantAgreement/ES/MINECO/MAT2014-52069-RThis project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 705089-MIR-CHROM-Cinfo:eu-repo/grantAgreement/EC/H2020/705089/EU/Investigating the microRNA-chromatin remodelling circuitry in cardiac development/MIR-CHROM-Cinfo:eu-repo/grantAgreement/EC/FP7/612338/EU/DNA-TRAP Delivery of Nucleic Acid-Based Therapeutics for the TReatment of Antibiotic-Resistant Pathogens/DNA-TRAPinfo:eu-repo/grantAgreement/EC/FP7/607142/EU/European Initial Training Network on Developmental and Computational Biology/DEVCOMinfo:eu-repo/grantAgreement/EC/FP7/604448/EU/Nanometrology Standardization Methods for Magnetic Nanoparticles/NANOMAGinfo:eu-repo/grantAgreement/ES/MINECO/RYC-2014-15512Nanoscale 10, 2 (2018), 690-704All rights reservedhttp://www.europeana.eu/rights/rr-f/info:eu-repo/semantics/openAccess