Effect of temperature and copper doping on the heterogeneous Fenton-like activity of Cux_xFe3−x_{3-x}O4_4 nanoparticles

Ferrite nanoparticles serve as potent heterogeneous Fenton-like catalysts, producing reactive oxygen species (ROS) for decomposing organic pollutants. We investigated the impact of temperature and copper content on the catalytic activity of nanoparticles with different oxidation states of iron. Via solvothermal synthesis, we fabricated copper-doped magnetite (Cu$_x$Fe$_{3-x}$O$_4$) with a Fe$^{2+}$/Fe ratio ~0.33 for the undoped system. Using a microwave-assisted method, we produced copper-doped oxidized ferrites, yielding a Fe$^{2+}$/Fe ratio of ~0.11 for the undoped nanoparticles. The ROS generated by the catalyst were identified and quantified by electron paramagnetic resonance, while optical spectroscopy allowed us to evaluate its effectiveness for the degradation of a model organic dye. At room temperature, the magnetite nanoparticles exhibited the most $\cdot$OH radical production and achieved almost 90% dye discoloration in 2 hours. This efficiency decreased with increasing Cu concentration, concurrently with a decrease in $\cdot$OH generation. Conversely, above room temperature, Cu-doped nanoparticles significantly enhance the dye degradation, reaching 100% discoloration at 90$^\circ$C. This enhancement is accompanied by a systematic increase in the kinetic constants, obtained from reaction equations, with Cu doping. This study highlights the superior stability and high-temperature catalytic advantages of copper ferrite holding promise for enhancing the performance of nanocatalysts for decomposing organic contaminants.Comment: 40 pages, 11 figure

Superparamagnetic iron oxide nanoparticles decorated mesoporous silica nanosystem for combined antibiofilm therapy

A crucial challenge to face in the treatment of biofilm-associated infection is the ability of bacteria to develop resistance to traditional antimicrobial therapies based on the administration of antibiotics alone. This study aims to apply magnetic hyperthermia together with controlled antibiotic delivery from a unique magnetic-responsive nanocarrier for a combination therapy against biofilm. The design of the nanosystem is based on antibiotic-loaded mesoporous silica nanoparticles (MSNs) externally functionalized with a thermo-responsive polymer capping layer, and decorated in the outermost surface with superparamagnetic iron oxide nanoparticles (SPIONs). The SPIONs are able to generate heat upon application of an alternating magnetic field (AMF), reaching the temperature needed to induce a change in the polymer conformation from linear to globular, therefore triggering pore uncapping and the antibiotic cargo release. The microbiological assays indicated that exposure of E. coli biofilms to 200 µg/mL of the nanosystem and the application of an AMF (202 kHz, 30 mT) decreased the number of viable bacteria by 4 log10 units compared with the control. The results of the present study show that combined hyperthermia and antibiotic treatment is a promising approach for the effective management of biofilm-associated infections.Depto. de Química en Ciencias FarmacéuticasFac. de FarmaciaTRUEpu

Iron oxide and iron oxyhydroxide nanoparticles impair SARS-CoV-2 infection of cultured cells

Background Coronaviruses usually cause mild respiratory disease in humans but as seen recently, some human coronaviruses can cause more severe diseases, such as the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the global spread of which has resulted in the ongoing coronavirus pandemic. Results In this study we analyzed the potential of using iron oxide nanoparticles (IONPs) coated with biocompatible molecules like dimercaptosuccinic acid (DMSA), 3-aminopropyl triethoxysilane (APS) or carboxydextran (FeraSpin™ R), as well as iron oxyhydroxide nanoparticles (IOHNPs) coated with sucrose (Venofer®), or iron salts (ferric ammonium citrate -FAC), to treat and/or prevent SARS-CoV-2 infection. At non-cytotoxic doses, IONPs and IOHNPs impaired virus replication and transcription, and the production of infectious viruses in vitro, either when the cells were treated prior to or after infection, although with different efficiencies. Moreover, our data suggest that SARS-CoV-2 infection affects the expression of genes involved in cellular iron metabolism. Furthermore, the treatment of cells with IONPs and IOHNPs affects oxidative stress and iron metabolism to different extents, likely influencing virus replication and production. Interestingly, some of the nanoparticles used in this work have already been approved for their use in humans as anti-anemic treatments, such as the IOHNP Venofer®, and as contrast agents for magnetic resonance imaging in small animals like mice, such as the FeraSpin™ R IONP. Conclusions Therefore, our results suggest that IONPs and IOHNPs may be repurposed to be used as prophylactic or therapeutic treatments in order to combat SARS-CoV-2 infection.This work was supported by the following Grants: CSIC-COV19-012/012202020E154 funded by the Spanish National Research Council Interdisciplinary Thematic Platform (PTI) Global Health (PTI Salud Global), SGL2103021 funded by the European Commission-NextGenerationEU (Regulation EU2020/2094) through CSIC’s Global Health Platform (PTI Salud Global); PDC2021-120759-100 funded by MCIN/AEI/10. 13039/50110 00110 33 and by the “European Union NextGenerationEU/PRTR”, PID2020-112685RB-100 funded by MCIN/AEI/10. 13039/50110 00110 33, and the “Atracción de Talento Investigador” programme (2017-T1/BMD-5155) funded by the “Comunidad de Madrid”. Y. Portilla was first a predoctoral FPU scholar (FPU15/06170) funded by MCIN/AEI/10. 13039/50110 00110 33 and by “ESF Investing in your future”, then a predoctoral scholar funded by CSIC-COV19-012/012202020E154 and is now a postdoctoral scholar funded by the European Commission-NextGenerationEU (Regulation EU2020/2094) through the CSIC’s Global Health Platform (PTI Salud Global, SGL2103021). D. López-García received a JAE-INTRO 2020 Fellowship from the Spanish National Research Council (CSIC, JAEINT-20-01805). V. Mulens-Arias was a postdoctoral scholar working under a Juan de La Cierva-Incorporación Contract (IJCI-2017-31447) funded by MCIN/AEI/10. 13039/50110 00110 33. N. Daviu is a predoctoral scholar (FPU18/04828) funded by MCIN/AEI/10. 13039/50110 00110 33 and by “ESF Investing in your future”. This research work was performed in the framework of the Nanomedicine CSIC HUB (ref. 202180E048).Peer reviewe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Superparamagnetic nanoreactors as highly efficient adsorbent for water purification en 10th International Conference on Fine Particle Magnetism (27-30 Mayo 2019)

[EN] The present study describes the surface modification of iron oxide magnetic nanoparticles with a double-shell coating of silica to obtain mesoporous superparamagnetic nanocomposites with high surface area, identified as nanoreactors (NRs), capable of providing a confined space for organic and inorganic pollutants removal. Adsorption tests were carried out for Lead (Pb2+) and methyl orange (MO) and the effects of different parameters such as pH, pollutant initial concentration, and contact time were analysed. The pseudo second-order model best described the adsorption kinetics for all NRs in the adsorption process of both, organic and inorganic pollutants. Intraparticle diffusion was also found to be involved in the MO adsorption, but is not the limiting stage. The adsorption isotherms were best described by the Langmuir model, suggesting that the adsorption takes place in monolayer. The maximum adsorption capacity value increases from 35 up to 50 mg/gNR with the increasing surface area for Pb2+ removal, while for MO it goes up to 240 mg/gNR. The NRs have excellent cyclability for MO sorption/desorption by simple acid treatment, recovering 100%during the first 4 cycles.Peer reviewe

New insights into the structural analysis of maghemite and (MFe2O4, M = Co, Zn) ferrite nanoparticles synthesized by a microwave-assisted polyol process

[EN] The search for more efficient, scalable, reproducible and standardized synthesis methods able to control particle size and crystallinity is still a challenge in nanotechnology. The one-pot microwave-assisted polyol process has been optimized for the synthesis of well-defined ferrite nanoparticles. Highly uniform and crystalline γ-Fe2O3, CoFe2O4 and ZnFe2O4 nanoparticles, with diameters below 14 nm have been prepared by an easy and reproducible one-pot microwave-assisted heating procedure in a polyol medium. A pure single phase and cubic spinel structure were confirmed by powder X-ray diffraction and Raman spectroscopy. Depending on the metal precursors, nanoparticles display magnetic features from superparamagnetic behaviour (Fe- A nd Zn-ferrites) to ferrimagnetism (Co ferrite) at room temperature. The iron oxidation state of 3+ and its short-range order coordination were studied by XAS (X-ray absorption spectroscopy). External field Mössbauer spectra, recorded at low temperature, confirmed the ferrimagnetic order with a Fe3+ and M2+ partial cationic distribution within both the A and B sites in zinc and cobalt ferrite, respectively. According to these results, the ferrite stoichiometry was (Zn0.70Fe0.30)[Zn0.30Fe1.70]O4 and (Co0.28Fe0.72)[Co0.72Fe1.28]O4. This journal isThis research was funded by the Spanish Ministry of Economy and Competitiveness under grants MAT2017-88148-R, MAT2017-86540-C4-1-R, RTI2018-095303-A-C52, and PGC2018-095642-B-I00. E. M. acknowledges financial support from the Juan de la Cierva Formación (FJCI-2015-23702) and to Comunidad de Madrid – Jóvenes Doctores project (SI1-PJI-2019-00366). L. G. acknowledges financial support from the Ramón y Cajal program (RYC-2014-15512). The authors would like to acknowledge the use of the Advanced Microscopy Laboratory (INA-Universidad de Zaragoza). A. S. and A. E. acknowledge financial support from the Comunidad de Madrid for the ‘‘Atracción de Talento Investigador’’ contracts (No. 2017-T2/IND5395 and 2018-T1/IND10058). A. E. is also grateful to the 2018/NMT-4321 and SEV-2016-0686 projects. The European Synchrotron (ESRF),Ministerio Español de Ciencia, Innovación y Universidades (MCIU) and Consejo Superior de Investigaciones Cientificas (CSIC) are acknowledged for the provision of synchrotron radiation facilities. We also thank the BM25- SpLine staff for the technical support beyond their duties

Tailoring the magnetic and structural properties of manganese/zinc doped iron oxide nanoparticles through microwaves-assisted polyol synthesis

Tuning the fundamental properties of iron oxide magnetic nanoparticles (MNPs) according to the required biomedical application is an unsolved challenge, as the MNPs’ properties are affected by their composition, their size, the synthesis process, and so on. In this work, we studied the effect of zinc and manganese doping on the magnetic and structural properties of MNPs synthesized by the microwave-assisted polyol process, using diethylene glycol (DEG) and tetraethylene glycol (TEG) as polyols. The detailed morpho-structural and magnetic characterization showed a correspondence between the higher amounts of Mn and smaller crystal sizes of the MNPs. Such size reduction was compensated by an increase in the global magnetic moment so that it resulted in an increase of the saturation magnetization. Saturation magnetization MS values up to 91.5 emu/g and NMR transverse relaxivities r2 of 294 s−1mM−1 were obtained for Zn and Mn- doped ferrites having diameters around 10 nm, whereas Zn ferrites with diameters around 15 nm reached values of MS∼ 97.2 emu/g and of r2∼ 467 s−1mM−1, respectively. Both kinds of nanoparticles were synthesized by a simple, reproducible, and more sustainable method that makes them very interesting for diagnostic applications as MRI contrast agents.This work was funded by the European Commission through the HOTZYMES Project (H2020-FETOPEN-RIA 829162) and European Research Council (ERC) through the European Union’s Horizon 2020 research and innovation programme (Grant agreement No. 853468). It was also funded by by the Spanish Ministry of Science and Innovation (AEI/FEDER, UE) through PID2020-113480RB-I00 project, and by the Comunidad de Madrid I+D+i grant program Atracción de Talento project 2018-T1/IND-1005, AECC Ideas Semilla 2019 and SEV-2016-0686 projects. It was also funded by the EU project NESTOR (101007629).Peer reviewe

Improving degradation of real wastewaters with self-heating magnetic nanocatalysts

[EN] Industrial effluents contain a wide range of organic pollutants that present harmful effects on the environment and deprived communities with no access to clean water. As this organic matter is resistant to conventional treatments, Advanced Oxidation Processes (AOPs) have emerged as a suitable option to counteract these envi-ronmental challenges. Engineered iron oxide nanoparticles have been widely tested in AOPs catalysis, but their full potential as magnetic induction self-heating catalysts has not been studied yet on real and highly contam-inated industrial wastewaters. In this study we have designed a self-heating catalyst with a finely tuned structure of small cores (10 nm) aggregates to develop multicore particles (40 nm) with high magnetic moment and high colloidal stability. This nanocatalyst, that can be separated by magnetic harvesting, is able to increase reaction temperatures (up to 90 ◦C at 1 mg/mL suspension in 5 min) under the action of alternating magnetic fields. This efficient heating was tested in the degradation of a model compound (methyl orange) and real wastewaters, such as leachate from a solid landfill (LIX) and colored wastewater from a textile industry (TIW). It was possible to increase reaction rates leading to a reduction of the chemical oxygen demand of 50 and 90%, for TIW and LIX. These high removal and degradation ability of the magnetic nanocatalyst was sustained with the formation of strong reactive oxygen species by a Fenton-like mechanism as proved by electron paramagnetic resonance. These findings represent an important advance for the industrial implementation of a scalable, non-toxic, self-heating catalysts that can certainly enhance AOP for wastewater treatment in a more sustainable and efficient way.This research was funded by the Spanish Ministry of Economy and Competitiveness under grant MAT2017-88148-R (AEI/FEDER, UE) and Consejo Superior de Invetigaciones Científícas PIE- 201960E062. This study was also supported by the USFQ Collaboration Grant 2018 Nº 11197 and the USFQ PoliGrants 2018–2019 Nº 12501. E.W., E.L.Jr and R.D.Z. acknowledge Argentine governmental agency ANPCyT (Project No. PICT-2016-0288 and PICT-2018-02565) and UNCuyo (Project No.06/ C527 and 06/C528) for the financial support.Peer reviewe

Superparamagnetic Iron Oxide Nanoparticles Decorated Mesoporous Silica Nanosystem for Combined Antibiofilm Therapy

A crucial challenge to face in the treatment of biofilm-associated infection is the ability of bacteria to develop resistance to traditional antimicrobial therapies based on the administration of antibiotics alone. This study aims to apply magnetic hyperthermia together with controlled antibiotic delivery from a unique magnetic-responsive nanocarrier for a combination therapy against biofilm. The design of the nanosystem is based on antibiotic-loaded mesoporous silica nanoparticles (MSNs) externally functionalized with a thermo-responsive polymer capping layer, and decorated in the outermost surface with superparamagnetic iron oxide nanoparticles (SPIONs). The SPIONs are able to generate heat upon application of an alternating magnetic field (AMF), reaching the temperature needed to induce a change in the polymer conformation from linear to globular, therefore triggering pore uncapping and the antibiotic cargo release. The microbiological assays indicated that exposure of E. coli biofilms to 200 µg/mL of the nanosystem and the application of an AMF (202 kHz, 30 mT) decreased the number of viable bacteria by 4 log10 units compared with the control. The results of the present study show that combined hyperthermia and antibiotic treatment is a promising approach for the effective management of biofilm-associated infections

Nanoparticules d'oxyde de fer avec activité antivirale contre le coronavirus sars et mers

Coronaviridae viruses usually cause mild respiratory disease in humans, nevertheless a new infectious disease caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally since December 2019, resulting in the ongoing 2019-2021 coronavirus pandemic. The present invention discloses the use of coated iron oxide nanoparticles (IONPs) for use in the treatment and/or prevention of viral infections caused by Coronaviridae, especially those caused by respiratory syndrome-related coronaviruses such as SARS-CoV, SARS-CoV-2 and MERS-CoV. The iron oxide nanoparticles are coated with biocompatible molecules and polymers which bind to the nanoparticle core via oxygen, nitrogen and sulfur donor atoms (e.g. dextran, (3-aminopropyl)triethoxysilane or dimercaptosuccinic acid, respectively). The IONPs were found stable, non-cytotoxic in vitro and can efficiently impair virus replication, transcription and production of infectious virus. Furthermore, the IONPs are suitable for oral, intranasal or parenteral administration in combination with a pharmaceutical carrier.Peer reviewedConsejo Superior de Investigaciones CientíficasA1 Solicitud de patente con informe sobre el estado de la técnic