Publications by authors named "Aida Serrano"

7 Publications

  • Page 1 of 1

Massive Intracellular Remodeling of CuS Nanomaterials Produces Nontoxic Bioengineered Structures with Preserved Photothermal Potential.

ACS Nano 2021 06 25;15(6):9782-9795. Epub 2021 May 25.

Laboratoire Matière et Systèmes Complexes MSC, UMR 7057, CNRS and University of Paris, 75205, Paris Cedex 13, France.

Despite efforts in producing nanoparticles with tightly controlled designs and specific physicochemical properties, these can undergo massive nano-bio interactions and bioprocessing upon internalization into cells. These transformations can generate adverse biological outcomes and premature loss of functional efficacy. Hence, understanding the intracellular fate of nanoparticles is a necessary prerequisite for their introduction in medicine. Among nanomaterials devoted to theranostics is copper sulfide (CuS), which provides outstanding optical properties along with easy synthesis and low cost. Herein, we performed a long-term multiscale study on the bioprocessing of hollow CuS nanoparticles (CuS NPs) and rattle-like iron oxide [email protected] core-shell hybrids ([email protected] NPs) when inside stem cells and cancer cells, cultured as spheroids. In the spheroids, both CuS NPs and [email protected] NPs are rapidly dismantled into smaller units (day 0 to 3), and hair-like nanostructures are generated (day 9 to 21). This bioprocessing triggers an adaptation of the cellular metabolism to the internalized metals without impacting cell viability, differentiation, or oxidative stress response. Throughout the remodeling, a loss of IONF-derived magnetism is observed, but, surprisingly, the CuS photothermal potential is preserved, as demonstrated by a full characterization of the photothermal conversion across the bioprocessing process. The maintained photothermal efficiency correlated well with synchrotron X-ray absorption spectroscopy measurements, evidencing a similar chemical phase for Cu but not for Fe over time. These findings evidence that the intracellular bioprocessing of CuS nanoparticles can reshape them into bioengineered nanostructures without reducing the photothermal function and therapeutic potential.
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http://dx.doi.org/10.1021/acsnano.1c00567DOI Listing
June 2021

Control of the Length of FeSiNbCuB Microwires to Be Used for Magnetic and Microwave Absorbing Purposes.

ACS Appl Mater Interfaces 2020 Apr 19;12(13):15644-15656. Epub 2020 Mar 19.

Departamento de Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain.

A combination of high-energy ball milling, vacuum filtering, and sedimentation processes has been demonstrated to be a useful approach to reduce, in a controlled way, the length of as-cast FeSiNbCuB amorphous magnetic microwires (MWs) and annealed material at 550 °C in nitrogen conditions. Homogeneous compositional microstructures with fairly narrow size distributions between 1300 and 11.7 μm are achieved, exhibiting tunable response as a soft magnetic material and as a microwave absorber. From the magnetic perspective, the soft magnetic character is increased with smaller length of the MWs, whereas the remanence has the opposite behavior mainly due to the structural defects and the loss of the shape anisotropy. From the microwave absorption perspective, a novel potential applicability is tested in these refined microstructures. This innovation consists of coatings based on commercial paints with a filling percentage of 0.55% of MWs with different lengths deposited on metallic sheets. Large attenuation values around -40 dB are obtained in narrow spectral windows located in the GHz range, and their position can be varied by combining different optimized lengths of MW. As an example of this powerful mechanism for absorbing microwaves at specific frequencies, MW lengths of 2 mm and 50 μm are chosen, where precise tailoring of the minimum reflection loss () is obtained in a range between 8.85 and 13.25 GHz. To confirm these experimental results, an effective medium standard model proposed for electrical permittivity is used. Experimental and theoretical results are consistent and these novel composites are also proposed as a feasible candidate for designing frequency-selective microwave absorbers on demand, with low filling percentages and high absorption intensity values.
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http://dx.doi.org/10.1021/acsami.9b21865DOI Listing
April 2020

Transformation Cycle of Magnetosomes in Human Stem Cells: From Degradation to Biosynthesis of Magnetic Nanoparticles Anew.

ACS Nano 2020 02 16;14(2):1406-1417. Epub 2020 Jan 16.

Laboratoire Matière et Systèmes, Complexes MSC, UMR 7057, CNRS and University of Paris , 75205 , Paris Cedex 13 , France.

The nanoparticles produced by magnetotactic bacteria, called magnetosomes, are made of a magnetite core with high levels of crystallinity surrounded by a lipid bilayer. This organized structure has been developed during the course of evolution of these organisms to adapt to their specific habitat and is assumed to resist degradation and to be able to withstand the demanding biological environment. Herein, we investigated magnetosomes' structural fate upon internalization in human stem cells using magnetic and photothermal measurements, electron microscopy, and X-ray absorption spectroscopy. All measurements first converge to the demonstration that intracellular magnetosomes can experience an important biodegradation, with up to 70% of their initial content degraded, which is associated with the progressive storage of the released iron in the ferritin protein. It correlates with an extensive magnetite to ferrihydrite phase transition. The ionic species delivered by this degradation could then be used by the cells to biosynthesize magnetic nanoparticles anew. In this case, cell magnetism first decreased with magnetosomes being dissolved, but then cells remagnetized entirely, evidencing the neo-synthesis of biogenic magnetic nanoparticles. Bacteria-made biogenic magnetosomes can thus be totally remodeled by human stem cells, into human cells-made magnetic nanoparticles.
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http://dx.doi.org/10.1021/acsnano.9b08061DOI Listing
February 2020

Towards Blue Long-Lasting Luminescence of Eu/Nd-Doped Calcium-Aluminate Nanostructured Platelets via the Molten Salt Route.

Nanomaterials (Basel) 2019 Oct 16;9(10). Epub 2019 Oct 16.

Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC, Kelsen 5, 28049 Madrid, Spain.

Calcia-alumina binary compounds doped with rare earths and some transition metals cations show persistent luminescence from the visible to the infrared range. Specifically, the blue light can be obtained through the Eu activator center in a potential host, such as dodecacalcium hepta-aluminate (CaAlO) and monocalcium aluminate (CaAlO). By doping with Nd, the persistent luminescence can be substantially prolonged; for this reason, the Eu/Nd pair is a potential choice for developing long-lasting blue luminescence. Herein, the phase evolution of the calcia-alumina system via molten salt synthesis is reported as a function of the synthesis temperature and the atmospheric environment. The fraction of CaAlO phase increases when the temperature is higher. Synthesized microparticles of platelet-type morphology represent isolated nanostructured ceramic pieces. Under visible light, the particles are white. This indicates that the followed process solves the dark-gray coloring of phosphor when is synthesized in a reduced atmosphere at high temperature. As regards the synthesis mechanism, which is assisted by the molten flux, the dissolution-diffusion transport process is promoted at the surface of the alumina microparticles. In fact, the emission intensity can be modulated through the phase of the Eu-doped calcium-aluminate discrete platelets synthesized. Consequently, the photoluminescence intensity depends also on the oxidation state of the Eu ion. X-ray absorption near-edge structure and photoluminescence measurements corroborate the Eu reduction and the grain coarsening with the enhancement of the blue emission. The doped phosphors with Eu/Nd show a broad and strong absorption in the region of 320-400 nm and a broad emission band at around 440 nm when they are excited in this absorption range. From a broader perspective, our findings prove that the CaAlO and CaAlO phases open new opportunities for research into the design of blue long-lasting emitters for a wide range of fields from ceramic to optoelectronic materials.
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http://dx.doi.org/10.3390/nano9101473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836158PMC
October 2019

Mn-Doping level dependence on the magnetic response of MnFeO ferrite nanoparticles.

Dalton Trans 2019 Aug 10;48(30):11480-11491. Epub 2019 Jul 10.

Dpto. de Química Inorgánica, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain.

Manganese/iron ferrite nanoparticles with different Mn doping grades have been prepared by a thermal decomposition optimized approach so as to ascertain the doping effect on magnetic properties and, especially, on the magnetic hyperthermia response. The oxidation state and interstitial position of Mn in the spinel structure is found to be critical. The particle size effect has also been studied by growing one of the prepared samples (from 10 to 15 nm in diameter) by a seed mediated growth mechanism. After analyzing the main structural and chemical parameters such as the Mn/Fe rate, crystalline structure, particle diameter, shape and organic coating, some Mn doping induced changes have been observed, such as the insertion of Mn cations yielded more anisotropic shapes. Magnetic characterization, carried out by DC magnetometry (M(H), M(T)) and electron magnetic resonance (EMR) techniques, has shown interesting differences between samples with varying compositions. Lower Mn doping levels lead to larger saturation magnetization values, while an increase of the Mn content causes the decrease of the effective magnetic anisotropy constant at low T. The homogeneous magnetic response under applied magnetic fields, together with the great effect of nanoparticle size and shape in such a response, has been confirmed by the EMR analysis. Finally, a detailed magnetic hyperthermia analysis has demonstrated the large influence of NP size and shape on the magnetic hyperthermia response. The optimized MnFeO_G sample with a diameter of 15 nm and slightly truncated octahedral shape is presented as an interesting candidate for future magnetic hyperthermia mediated biomedical treatments.
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http://dx.doi.org/10.1039/c9dt01620aDOI Listing
August 2019

Transparent Sol-Gel Oxyfluoride Glass-Ceramics with High Crystalline Fraction and Study of RE Incorporation.

Nanomaterials (Basel) 2019 Apr 3;9(4). Epub 2019 Apr 3.

Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, Spain.

Transparent oxyfluoride glass-ceramic films and self-supported layers with composition 80SiO₂-20LaF₃ doped with Er have been successfully synthesized by sol-gel process for the first time. Crack-free films and self-supported layer with a maximum thickness up to 1.4 µm were obtained after heat treatment at the low temperature of 550 °C for 1 min, resulting in a LaF₃ crystal fraction of 18 wt%, as confirmed by quantitative Rietveld refinement. This is the highest value reported up to now for transparent oxyfluoride glass-ceramics prepared by sol-gel. This work provides a new synthesis strategy and opens the way to a wide range of potential applications of oxyfluoride glass-ceramics. The characterization by a wide range of techniques revealed the homogeneous precipitation of LaF₃ nanocrystals into the glass matrix. X-ray absorption spectroscopy and electron paramagnetic resonance confirmed that the Er ions are preferentially embedded in the low phonon-energy LaF₃ nanocrystals. Moreover, photoluminescence (PL) measurements confirmed the incorporation of dopants in the LaF₃ nanocrystals. The effective concentration of rare-earth ions in the LaF₃ nanocrystals is also estimated by X-ray absorption spectroscopy.
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http://dx.doi.org/10.3390/nano9040530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6523291PMC
April 2019

Precise Tuning of the Nanostructured Surface leading to the Luminescence Enhancement in SrAlO Based Core/Shell Structure.

Sci Rep 2017 03 28;7(1):462. Epub 2017 Mar 28.

Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC, Kelsen 5, 28049, Madrid, Spain.

Intensive research has been focused on the synthesis of long-lasting SrAlO:EuDy in luminescent materials field. Traditionally, SrAlO:EuDy is synthesized in bulk form by solid state. However, their development remains restrained due to this technique is not compatible with large-scale production, sustainability and nanometer-scale requirements. Despite nano-range particles have been obtained by chemical routes, photoluminescence response decreases and application became unpractical. It remains a challenge to synthesize nonrare-earth (RE) phosphors with high photoluminescence. One major challenge for the luminescent materials community is to devise methods to deliver innovative, sustainable and cost effective solutions for the reduction of RE because of the lack of RE availability. Here, we suggest a solution based on molten salts, obtaining nanosheets or micro/nanostructured SrAlO:Eu, Dy particles with core-shell structure, employing only 50% of standard amounts of RE. Core-size and shell thickness and crystallinity can be tuned by post-thermal treatment, through which can be modulated the Eu fraction. We find that our methodology leads the functional features of the analogous micron counterpart. These results can be considered a great achievement to scale-up the process. Besides, the harmful collateral effect of nanotechnology must be addressed by using new safe by design core-shell nanostructures.
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http://dx.doi.org/10.1038/s41598-017-00541-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5428670PMC
March 2017
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