Maite Insausti

Maite Insausti
Universidad del País Vasco / Euskal Herriko Unibertsitatea | UPV/EHU · Inorganic Chemistry

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130
Publications
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2,091
Citations
Citations since 2016
25 Research Items
789 Citations
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140
2016201720182019202020212022020406080100120140

Publications

Publications (130)
Article
Full-text available
Nanosystems that simultaneously contain fluorescent and magnetic modules can offer decisive advantages in the development of new biomedical approaches. A biomaterial that enables multimodal imaging and contains highly efficient nanoheaters together with an intrinsic temperature sensor would become an archetypical theranostic agent. In this work, we...
Article
We present results concerning the synthesis of FexCo1-x (0<x<1) alloy nanoparticles (NPs) with different compositions by the chemical reduction technique and subsequent structural (XRD patterns), morphological (TEM images) and magnetic (VSM magnetometry) characterization. We have got excellent quality NPs in the cubic bcc structure showing a room t...
Article
The achievement of a successful heating power response of Fe3O4 nanoparticles for being applied in magnetic hyperthermia entails an exhaustive control of their magnetic characteristics and therefore, of the synthesis method employed. Despite the fact that one of the best wet-chemical methods to finely adjust Fe3O4 nanoparticles (NPs) size over 15 n...
Article
The main objective of the preparation of the Fe3-xGaxO4 (0.14 ≤ x ≤ 1.35) system was to further the knowledge of the magnetic response of Ga3+-doped magnetite for application as MRI contrast agents. With this purpose, monodisperse nanoparticles between 7 and 10 nm with different amounts of gallium were prepared from an optimized protocol based on t...
Article
Full-text available
Among iron oxide phases, magnetite (Fe3O4) is often the preferred one for nanotechnological and biomedical applications because of its high saturation magnetization and low toxicity. Although there are several synthetic routes that attempt to reach magnetite nanoparticles (NPs), they are usually referred as “IONPs” (iron oxide NPs) due to the great...
Article
Full-text available
The currently existing magnetic hyperthermia treatments usually need to employ very large doses of magnetic nanoparticles (MNPs) and/or excessively high excitation conditions (H × f > 1010 A/m s) to reach the therapeutic temperature range that triggers cancer cell death. To make this anticancer therapy truly minimally invasive, it is crucial the de...
Article
Full-text available
Recently, our collaborative work in the fabrication of a magnetorheological fluid (MRF) containing high magnetization FeCo nanoparticles (NPs, fabricated in our laboratories using the chemical reduction technique; MS = 212 Am2/kg) as magnetic fillers have resulted in a new MRF with superior performance up to 616.7 kA/m. The MRF had a yield stress v...
Article
We present results concerning the fabrication of a new magnetorheological fluid with FeCo magnetic nanoparticles (NPs) as magnetic fillers. These NPs have been fabricated by using the chemical reduction technique and show a pure crystalline phase with size ranging among 30–50 nm and high magnetization, 212 ± 2 A m² kg⁻¹. They agglomerate due to the...
Article
Full-text available
Aim The Specific Absorption Rate (SAR) is the key parameter to optimize the effectiveness of magnetic nanoparticles in magnetic hyperthermia. AC magnetometry arises as a powerful technique to quantify the SAR by computing the hysteresis loops' area. However, currently available devices produce quite limited magnetic field intensities, below 45mT, w...
Article
Full-text available
Local heat generation from magnetic nanoparticles (MNPs) exposed to alternating magnetic fields can revolutionize cancer treatment. However, the application of MNPs as anticancer therapy is limited by serious drawbacks. Foremost among these are the fast uptake and biodegradation of NPs by cancer cells and the unpredictable magnetic behavior of NPs...
Article
The coordination of photosensitizing dyes to zinc oxide nanoparticles (ZnO NPs) has attracted extensive attention as promising candidates for applications in solar cells. Here, we report the synthesis of ZnO NPs functionalized with geometric isomers of ruthenium(II)-polypyridyl complexes and a preliminary study of their photophysical properties by...
Article
We present results of the synthesis and characterization of Fe—Co—V high magnetization ferromagnetic nanoparticles (NPs) fabricated by two physical routes: laser ablation in liquid flow and mechanical ball milling. As characterizing techniques, we used dynamic light scattering, X-ray diffraction, transmission and scanning electron microscopy, and m...
Article
Most studies of magnetic nanoparticle-based hyperthermia utilize iron oxide nanoparticles smaller than 20 nm, which are intended to have a superparamagnetic behavior (SP-MNPs). However, the heating power of larger magnetic nanoparticles with non-fluctuating or fixed magnetic dipoles (F-MNPs) can be significantly greater than the one of SP-MNPs if h...
Article
Manganese/iron ferrite nanoparticles with different Mn2+/3+ doping grades have been prepared by a thermal decomposition optimized approach so as to ascertain the doping effect in magnetic properties and, specially, in the magnetic hyperthermia response. The oxidation state and interstitial position of Mn in the spinel structure has shown to be crit...
Article
Two major limitations for nanoparticle based magnetic hyperthermia in theranostics are the delivery of a sufficient number of magnetic nanoparticles (MNPs) with high heating power to specific target cells and...
Article
To improve the selectivity of magnetic nanoparticles for tumor treatment by hyperthermia, Fe3O4 nanoparticles have been functionalized with a peptide of the type arginine-glycine-aspartate (RGD) following a “click” chemistry approach. The RGD peptide was linked onto the previously coated nanoparticles in order to target αvβ3 integrin receptors over...
Article
Full-text available
With the aim of studying the influence of synthesis parameters in structural and magnetic properties of cobalt-doped magnetite nanoparticles, Fe3-xCo x O₄ (0 <x< 0.15) samples were synthetized by thermal decomposition method at different reaction times (30-120 min). The Co ferrite nanoparticles are monodisperse with diameters between 6 and 11 nm an...
Article
The interplay between chemical inhomogeneities and magnetic properties in iron alloys is a subtle question that affects several nanoalloys with potential technological and biomedical applications. Herein below, we focus on the FCC palladium rich–iron nanoparticle system, specifically in three samples that reflect the key influence of synthesis cond...
Article
Full-text available
Thiosemicarbazones and their metal derivatives have long been screened as antitumor agents, and their interactions with DNA have been analysed. Herein, we describe the synthesis and characterization of compounds containing [CuL](+) entities (HL = pyridine-2-carbaldehyde thiosemicarbazone) and adenine, cytosine or 9-methylguanine, and some of their...
Article
Full-text available
This work reports important advances in the study of magnetic nanoparticles (MNPs) related to their application in different research fields such as magnetic hyperthermia. Nanotherapy based on targeted nanoparticles could become an attractive alternative to conventional oncologic treatments as it allows a local heating in tumoral surroundings witho...
Data
Additional experimental information. The Supporting Information includes a representative scheme of the functionalization method of Fe3O4 NPs, a description of the preparation of RGD peptide, the heat induction procedure and additional figures of the XRD, TGA and FTIR characterization.
Article
Highly monodispersed palladium nanoparticles have been synthesized by a two-phase reduction method using two different capping agents, alkylamines and alkanethiols. The influence of ligand type in the properties of palladium nanoparticles have been analyzed in detail by means of several techniques as Infrared and Ultraviolet-Visible Spectroscopy, X...
Article
ABSTRACT With the aim of improving the response in magnetic hyperthermia treatments and other biomedical applications, a nanoparticle system based on nickel ferrites has been investigated. Monodisperse ferrite nanoparticles with different proportions of Ni2+ ions and sizes have been produced by an optimized synthesis based on the thermal decomposit...
Conference Paper
TiO2 nanotubes have been synthesized using a 2-step strategy that involves the hydrothermal preparation of intermediate titanates followed by a subsequent thermal/hydrothermal treatment of these species to produce the desired oxide. In the first step the influence of parameters such as temperature, pH or reaction time on the composition, structure...
Conference Paper
Full-text available
Background: RGD are thought to selectively adhere to integrins from cancer cells and endothelial cells from tumor vessels. Hyperthermia induced with RGD-Magnetic-Nanoparticles (MNp) might induce necrosis of liver tumors. Methods: CC-531 colorectal cancer cells were inoculated into the liver of WAG syngeneic rats. One month later, MNp were inoculate...
Article
Palladium-rich Iron nanoparticles in the 4-8 nm range have been produced by a combination of two methods: the thermal decomposition of organometallic precursors and the reduction of metallic salts by a polyol. Herein, it is shown how the details of the synthesis have a striking impact on the magnetic and morphological properties of the final produc...
Article
Full-text available
Highly monodispersed palladium nanoparticles have been synthesized by a two-phase reduction method using two different capping agents, alkylamines and alkanethiols. The influence of ligand type in the properties of palladium nanoparticles have been analyzed in detail by means of several techniques as Infrared and Ultraviolet-Visible Spectroscopy, X...
Article
Full-text available
New thiosemicarbazonecopper(II) compounds with formulae [{Cu(L')Cl}(2)] 1, [{Cu(L')l}(2)] 2, [{CuL(H2O)}(2)](SiF6)center dot 4H(2)O 3, [{Cu(L')(H2O)}(2)][Cu(L')(H2O)(2)](2)-(SiF6)(2)center dot 8H(2)O 4, Cu(HL)(SiF6)center dot 4H(2)O 5, {Cu(HL)(H2O)(SiF6)}(n)center dot nH(2)O 6 and Cu(HL')(SiF6)center dot 3H(2)O 7 have been synthesized and character...
Article
Full-text available
Monodispersed Fe3O4 nanoparticles have been synthesized by a thermal decomposition method based on the seeded-growth technique, achieving size tunable nanoparticles with high crystallinity and high saturation magnetization. EMR spectroscopy becomes a very efficient complementary tool to determine the fine details of size distributions of MNPs and e...
Article
New thiosemicarbazonecopper(II) compounds with formulae [{CuL(H2O)}{CuL(SO4)}]·H2O 1, [{CuL(H2O)}{CuL(SO4)}]n·nH2O 2 and [Cu(HL′)(SO4)(H2O)]·0.75H2O 3, (HL = pyridine-2-carbaldehyde thiosemicarbazone, and HL′ = pyridine-2-carbaldehyde 4N-methylthiosemicarbazone) have been synthesized and characterized by elemental analysis, FAB+ mass spectrometry,...
Article
Full-text available
Magnetite nanoparticles have been synthesized at different temperatures in order to get nanoparticles of different average sizes. Powders of the synthesized nanoparticles were introduced in a radio frequency electromagnetic apparatus built to perform hyperthermia measurements in laboratory animals. The nanoparticles synthesized at 80 degrees C, the...
Article
The interaction of nanoparticles with cells has been a focus of interest during the past decade. We report the fabrication and characterization of hydrosoluble Fe₃O₄@Au nanoparticles functionalized with biocompatible and fluorescent molecules and their interaction with cell cultures by visualizing them with confocal microscopy. Gold covered iron ox...
Article
Full-text available
To evaluate, in an experimental model, the reliability of MRI for determining whether a higher iron concentration was obtained in tumor tissue than in normal liver parenchyma after intra-arterial administration of Fe₃O₄ lipophilic nanoparticles. WAG/RijCrl rats were inoculated in the left hepatic lobe with 25,000 syngeneic CC-531 colon adenocarcino...
Chapter
Full-text available
Oleic acid/oleylamine capped Fe1-xPdx (x=0.16, 0.20, 0.25) nanoparticles have been synthesized using a diol as reducing agent in order to get nanoparticles of different average sizes and coatings. Composition and morphology were analyzed by infrared spectroscopy (IR), X-Ray Diffraction (RXD), thermogravimetry (TG) and Transmission Electron Microsco...
Chapter
Magnetite based nanoparticles functionalized with different ligands have been obtained by optimization of two synthetic methods. Gold surrounded Fe3O4 nanoparticles capped with oleic acid and oleylamine were achieved by thermal decomposition of metallo-organic precursors. By this way nanoparticles with perfectly defined size within 3.5 nm to 7 nm i...
Article
This paper describes a method for effective separation of the pure binder fraction of lime mortars for reliable radiocarbon dating. The methodology allows removal of the detrital carbonate fraction and the unburnt limestone particles, obtaining particles of under 1 μm. The extracted fraction ensured that all carbonate has been generated by slaked l...
Article
This paper describes a method for effective separation of the pure binder fraction of lime mortars for reliable radiocarbon dating. The methodology allows removal of the detrital carbonate fraction and the unburnt limestone particles, obtaining particles of under 1 μm. The extracted fraction ensured that all carbonate has been generated by slaked l...
Conference Paper
PURPOSE To evaluate the MRI as a tool for assessing the vascular distribution of Fe3O4 thermotherapeutic magnetic nanoparticles (Fe-np), into tumor and healthy liver tissue in a rat model. METHOD AND MATERIALS 80 WAG/Rij rats were used in 8 consecutive series. On day 0, rats were inoculated into liver with colocarcinoma cells and randomized as con...
Article
The creation of porous materials with three-dimensional periodicity has been identified as being of potential interest for increasing the overall performance of solid oxide fuel cells (SOFC). In this work, we have investigated the formation of pore systems in the nanometer scale by replicating colloidal templates. Templating methods have been used...
Article
To use imaging and laboratory techniques to evaluate the vascular distribution of magnetofluid in a rat model of liver metastases. The livers of 33 WAG/Rij Crl rats were seeded with CC-531 colorectal cancer cells. After we checked tumor development, 10 rats received hepatic intra-arterial infusions of Lipiodol(®) with nanoparticles of Fe(3)O(4) in...
Article
One of the major challenges prior to a proper application of magnetic iron oxide nanocrystals is not only to understand the influence of the synthetic parameters on the final characteristics of the nanoparticles but also to optimize characterization methods in order to understand the magnetic behavior. First, a systematic study of the different par...
Article
The magnetic and electrical transport properties of regioregular poly(3-hexylthiophene)-capped Au nanoparticles (NPs) doped with iodine have been investigated to clarify the effectiveness of conductive polymer capping on the induction of ferromagnetism in Au. The room-temperature magnetization curve of the undoped polythiophene-capped Au NPs exhibi...
Article
Copper is known as a pearlite promoter in cast iron and has been used as such for a long time, most often together with low amounts of manganese. Literature data, however, has shown that these two elements act differently on the ferritic and pearlitic transformations. In order to provide more insight in the role of this element on the solid-state t...
Article
Full-text available
New polyoxometallate–thiosemicarbazone hybrid compounds derived from pyridine-2-carbaldehyde thiosemicarbazone (HL), pyridine-2-carbaldehyde N4-methylthiosemicarbazone (HL′) and their copper(II) complexes have been synthesized. Their formulae are (H2L)4(Mo8O26)(H2O)4 (1), [{(HL)2H}2(Mo6O19)]·C3H6O·0.24H2O (2), [(H2L′)4(HL′)2(Mo8O26)(H2O)2] (3), [{C...
Article
Full-text available
Dodecanethiol capped Ag nanoparticles (NPs) have been independently synthesized by the well-known Brust method under the same physical-chemical conditions. The obtained NP present similar sizes (∼2 nm ) but different magnetic behaviors. The extended x-ray absorption fine structure analyses at the K -edge of Ag did not reveal any noticeable structur...
Article
The magnetic and optical properties of regioregular poly(3-hexylthiophene)-capped Au nanoparticles (NPs) have been investigated in order to clarify the effectiveness of polythiophene capping on the induction of ferromagnetism in Au. The room-temperature magnetization curve of the polythiophene-capped Au NPs exhibits a clear hysteresis behavior with...
Article
The Nd0.7A0.3Mn1-xBxO3 (A = Pb, Cd; B = Fe, Co, Ni; x = 0, 0.1) compounds have been synthesized using the sol-gel method and characterized by redox titration and X-ray diffraction. The replacement of manganese ions by Fe, Co or Ni implies a decrease in the ferromagnetic (or metal-insulator) transition temperature. The ZFC magnetization drops to zer...
Article
Full-text available
The crystal structures of [(ppy)Pd(mu-pz)](2) (ppy = 2-(2-pyridyl)phenyl, pz = pyrazol-1-yl) (1) and two different solvatomorphs of it, [(ppy)Pd(mu-pz)](2) x 1/2 CH(2)Cl(2) (2) and [(ppy)Pd(mu-pz)](2) x 1/2 CHCl(3) (3) have been elucidated by powder (1 and 2) and single crystal (3) X-ray diffraction. In all of them two molecules fit together follow...
Article
Different dodecanethiol capped Au nanoparticles (NP) with similar sizes (∼2 nm ) but different ferromagnetic signals at room temperature have been investigated by means of x-ray absorption spectroscopy at the Au L<sub>3</sub> -edge. The reversion of the x-ray magnetic circular dichroism signal with the change of sign of the external applied magneti...
Article
In the present paper we report the magnetic characterization of silver-iron oxide nanocomposite obtained by the chemical microemulsion method. TEM images and X-ray diffractograms show that the nanocomposite consists of Ag nanoparticles of ∼ 7 nm surrounded by a quasiamorphous matrix. The ZFC–FC curves and Mössbauer spectra obtained at different tem...
Article
Monodisperse magnetite nanoparticles coated with organic ligands have been chemically synthesised by using the poliol method. Modifying the synthetic conditions, particle diameter can be tuned from 3.5 to 7.1nm. In order to investigate the critical size effects on the magnetic behavior of the samples, Fe3O4 nanoparticles have been fully characteriz...
Article
Ever since the first studies of magnetic Au nanoparticles (NPs) were published, few have been the element specific techniques or microscopic probes used to unequivocally determine the origin of their novel magnetic behavior. Here, we report muon spin relaxation (μSR) results of dodecanethiol capped Au NPs, showing the inherent signature of an order...
Article
The two double perovskite oxides Sr2AlSbO6 and Sr2CoSbO6 were prepared and their structures studied with the X-ray powder diffraction method. At room temperature the crystal structure of Sr2AlSbO6 is cubic (Fm3¯m), with a=5.6058(1)A˚. It was found that depending on the preparation conditions, the Al3+ and Sb5+ cations can be either entirely or part...
Article
Chemical and mineralogical analyses were carried out on historical lime mortars from the parish church of Santa María La Real (Guipúzcoa). The study included various periods ranging from Roman to modern times and allowed the identification of various types of raw materials. In order to obtain pure binder, free of carbonate aggregates and charcoal p...
Article
Water in oil microemulsion technique has been used to obtain silver nanoparticles with a mean size of 7 nm surrounded by a matrix of 2 nm γ-Fe2O3 nanoparticles. Magnetic measurements of the sample exhibit a cusp in the ZFC curve at 50 K, which corresponds to the blocking temperature. A detailed study of the thermal evolution of EPR spectra has been...
Article
The effect of Fe doping on the ferromagnetic Nd0.7Pb0.3Mn1-xFexO3 (x=0, 0.025, 0.05, 0.075, 0.1) phases has been studied in order to analyze the double-exchange interaction. The structural and magnetic study has been carried out by neutron powder diffraction and susceptibility measurements between 1.7 and 300 K. The substitution of Fe at the Mn sit...
Article
The crystallization of the Fe75Zr25 as-milled amorphous alloy has been studied by Mössbauer spectroscopy. The process begins at around 880 K with the complete and fast crystallization of the amorphous phase into the crystalline α-Fe and Fe2Zr ones but, from around 915 K, there is a sudden phase transformation into the Fe23Zr6 phase, which remains s...
Article
The sarkinite, Mn-2(OH)ASO(4), mineral has been synthesized in laboratory as pure phase under mild hydrothermal conditions. The decomposition process of the hydroxiarsenate compound is strongly dependent on the atmospheric conditions. The results of the thermal treatment in air or argon are quite different. In this way, a new black phase appears in...
Article
The BaFeO2.95 oxide has been obtained from thermal decomposition of the [BaFe(C3H2O4)2(H2O)4] metallo-organic precursor at 800°C under atmospheric oxygen pressure as small and homogeneous particles. From electronic paramagnetic resonance data, a metallic behavior in the 230–130K temperature range has been observed. Magnetic measurements confirm the...
Article
The CaMnO3−x (x=0 and 0.02) mixed oxide was synthesized from both thermal treatment of the [CaMn(C3H2O4)2(H2O)4] metallo-organic precursor and ceramic method. In the case of the latter method, temperatures of 1350°C and 50h were necessary; however, lower temperatures, 800°C, and shorter reaction times, 15h, were utilized in the attainment of the mi...
Article
The double perovskites, Sr2FeReO6 and Sr2FeRe0.9M0.1O6 (M=Nb, Ta) have been obtained by soft synthesis methods which yield homogeneous particles of micrometric grain size. The materials have been studied by X-ray and neutron powder diffraction, scanning electron microscopy and magnetic measurements. Rietveld refinements show that the compounds adop...
Article
The crystal structure of the ordered double perovskite Sr2MnTeO6 has been refined at ambient temperature from high resolution neutron and x-ray powder diffraction data in the monoclinic space group P 121/n 1 with a = 5.7009(1) Å, b = 5.6770(1) Å, c = 8.0334(1) Å and β = 90.085(1)°. This represents a combination of in-phase (+) and out-of-phase (−)...
Article
Metallo-organic complexes with the formula [BaMn1−xMx(C3H2O4)2(H2O)4], where M =Fe, Co or Cu (0⩽x⩽1), were synthesised and characterised. All of them are isostructural and crystallise in the space group Pccn. The crystal structure has been described as a two-dimensional (2D) arrangement of M–malonate layers extended along the (010) crystallographic...
Article
Full-text available
Structural, electrical and magnetic properties of Cd-doped La0.7(Ca0.3−xCdx)MnO3 (0⩽x⩽0.3) manganites are presented. All compositions were indexed in the orthorhombic (Pnma) space group, except the Cd0.3 sample, indexed as a combination of trigonal (R3̄c) and orthorhombic (Pnma) space groups. Substitution of Ca by Cd has a strong influence on the m...
Article
Complexes with formula [BaM(C3H2O4)2(H2O)4], where M = Fe or Co, were synthesised and characterised. These two types of complexes are isostructural and crystallise in the Pccn space group. Their structure consists of two-dimensional networks of octahedral MO6 polyhedra in which the transition metal ions are coordinated by bridging malonate ligands,...
Article
Electrodeposition in the potentiostatic mode has been used to produce Cu–Co metastable alloys. The influence of different plating parameters, such as bath composition, working electrode voltage (vs. reference) and intensity of agitation, on the composition and properties of the deposit has been investigated. A broad range of compositions (2–26 at.%...