BUSCADOR RECOLECTA

Digital.CSIC. Repositorio Institucional del CSIC

oai:digital.csic.es:10261/305773

Stimuli-responsive nanomaterials are very attractive for biomedical applications. They can be activated through external stimuli or by the physico-chemical conditions present in cells or tissues. Here, we describe the preparation of hybrid iron oxide-manganese oxide core-satellite shell nanostructures that change their contrast mode in magnetic resonance imaging (MRI) from T2 to T1, after being internalized by cells. This occurs by the dissolution of the MnO2 of the shell, preserving intact the iron oxide at the core. First, we study the seeded-growth synthesis of iron oxide-manganese oxide nanoparticles studying the effect of varying the core size of the magnetic seeds and the concentration of the surfactant. This allows tuning the size and shape of the final hybrid nanostructure. Then, we show that the shell can be removed by a redox reaction with glutathione, which is naturally present inside the cells at much higher concentrations than outside the cells. Finally, the dissolution of the MnO2 shell and the change in the contrast mode is confirmed in cell cultures. After this process, the iron oxide nanoparticles at the core remain intact and are still active as heating mediators when an alternating magnetic field is applied., This work was supported by the Ministerio de Ciencia e Innovación (PID2019-106301RB-I00 to GS and PGC2018-096016-B-I00 to L.G.), Instituto de Salud Carlos III (PT20/00044; co‐funded by European Union, European Regional Development Fund, ERDF, “A way of making Europe”), Ministerio de Economía y Competitividad (SAF2017-87305-R), Comunidad de Madrid (fellowships PEJD-2016/IND-2293 and IND2017/IND-7809; projects B2017/BMD-3867; P2018/NMT-4321), European Commission H2020 programme (project NOCANTHER, grant agreement no. 685795), and Asociación Española Contra el Cáncer. IMDEA Nanociencia acknowledges support from the 'Severo Ochoa' Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN) and the Pro CNIC Foundation. L.G. acknowledges financial support from the Ramón y Cajal program (RYC-2014-15512). N. L-G also thanks the Spanish Education Ministry for the funding (FPU18/02323). P. M-R- acknowledges the support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686)., Peer reviewed