Maite Insausti

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

In this work, we discuss the challenges associated with measuring and interpreting the vibrational properties of nanomaterials at mid- and far-infrared frequencies, where vibrational bands are often broad and overlapping. This issue is compounded by the complex interaction between infrared light and particulate samples, which depends on packing den...

Neurodegenerative diseases involve progressive neuronal death. Traditional treatments often struggle due to solubility, bioavailability, and crossing the Blood-Brain Barrier (BBB). Nanoparticles (NPs) in biomedical field are garnering growing attention as neurodegenerative disease drugs (NDDs) carrier to the central nervous system. Here, we introdu...

Neurodegenerative diseases involve progressive neuronal death. Traditional treatments often struggle due to solubility, bioavailability, and crossing the Blood-Brain Barrier (BBB). Nanoparticles (NPs) in biomedical field are garnering growing attention as neurodegenerative disease drugs (NDDs) carrier to the central nervous system. Here, a specific...

In the last few decades, the use of iron oxide nanoparticles (IONPs) with magnetic properties, especially in biomedicine, has gained a great attention due to the wide range of applications of those systems in various fields. In the present work, iron oxide nanoparticles (IONPs) using β-cyclodextrin (β-CD) as capping agent were synthesized by normal...

In recent years, much effort has been invested into developing multifunctional drug delivery systems to overcome the drawbacks of conventional carriers. Magnetic nanoparticles are not generally used as carriers but can be functionalised with several different biomolecules and their size can be tailored to present a hyperthermia response, allowing f...

The use of perchlorato ancillary ligands, with relatively low coordinating ability, nicely illustrates a rich structural diversity in thiosemicarbazonecopper(II), TSC-Cu(II), systems. Five compounds with formulae {[CuL(OH2)][CuL(OClO3)]}n·nClO4·2nH2O (1), [{CuL(OClO3)}2] (2), [Cu(HL)(OClO3)2(OH2)]...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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.

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...

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...

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...

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...

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...

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...

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...

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...

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,...

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...

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...

Purpose 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. Materials and methods WAG/RijCrl rats were inoculated in the left hepatic lobe with 25,000 syng...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

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...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

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...

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...

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...

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 L₃ -edge. The reversion of the x-ray magnetic circular dichroism signal with the change of sign of the external applied magneti...

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...

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...

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...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

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...

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...