Crippa, Federica Rodriguez-Lorenzo, Laura Hua, Xiao Goris, Bart Bals, Sara Garitaonandia, José S. Balog, Sandor Burnand, David Hirt, Ann M. Haeni, Laetitia Lattuada, Marco Rothen-Rutishauser, Barbara Petri-Fink, Alke 2019-07-26 Magnetic hyperthermia has the potential to play an important role in cancer therapy and its efficacy relies on the nanomaterials selected. Superparamagnetic iron oxide nanoparticles (SPIONs) are excellent candidates due to the ability of producing enough heat to kill tumor cells by thermal ablation. However, their heating properties depend strongly on crystalline structure and size, which may not be controlled and tuned during the synthetic process; therefore, a postprocessing is needed. We show how thermal annealing can be simultaneously coupled with ligand exchange to stabilize the SPIONs in polar solvents and to modify their crystal structure, which improves hyperthermia behavior. Using high-resolution transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, vibrating sample magnetometry, and lock-in thermography, we systematically investigate the impact of size and ligand exchange procedure on crystallinity, their magnetism, and heating ability. We describe a valid and simple approach to optimize SPIONs for hyperthermia by carefully controlling the size, colloidal stability, and crystallinity. application/pdf https://folia.unifr.ch/global/documents/308110 https://folia.unifr.ch/documents/308110/files/pet_pts.pdf https://folia.unifr.ch/documents/308110/files/pet_pts_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/acsanm.9b00823 info:eu-repo/semantics/openAccess License undefined ACS Applied Nano Materials. - 2019, vol. 2, no. 7, p. 4462–4470 info:eu-repo/classification/udc/54 Phase transformation of superparamagnetic iron oxide nanoparticles via thermal annealing: implications for hyperthermia applications http://purl.org/coar/resource_type/c_6501