Publications by authors named "Antonio Topete"

15 Publications

  • Page 1 of 1

Microfluidics-assisted conjugation of chitosan-coated polymeric nanoparticles with antibodies: Significance in drug release, uptake, and cytotoxicity in breast cancer cells.

J Colloid Interface Sci 2021 Jun 13;591:440-450. Epub 2021 Feb 13.

Laboratorio de Inmunología, Departamento de Fisiología, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara 44340, Mexico. Electronic address:

Nanoparticle-based drug delivery systems, in combination with high-affinity disease-specific targeting ligands, provide a sophisticated landscape in cancer theranostics. Due to their high diversity and specificity to target cells, antibodies are extensively used to provide bioactivity to a plethora of nanoparticulate systems. However, controlled and reproducible assembly of nanoparticles (NPs) with these targeting ligands remains a challenge. In this context, determinants such as ligand density and orientation, play a significant role in antibody bioactivity; nevertheless, these factors are complicated to control in traditional bulk labeling methods. Here, we propose a microfluidic-assisted methodology using a polydimethylsiloxane (PDMS) Y-shaped microreactor for the covalent conjugation of Trastuzumab (TZB), a recombinant antibody targeting HER2 (human epidermal growth factor receptor 2), to doxorubicin-loaded PLGA/Chitosan NPs (PLGA/DOX/Ch NPs) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysulfosuccinimide (sNHS) mediated bioconjugation reactions. Our labeling approach led to smaller and less disperse nanoparticle-antibody conjugates providing differential performance when compared to bulk-labeled NPs in terms of drug release kinetics (fitted and analyzed with DDSolver), cell uptake/labeling, and cytotoxic activity on HER2 + breast cancer cells in vitro. By controlling NP-antibody interactions in a laminar regime, we managed to optimize NP labeling with antibodies resulting in ordered coronas with optimal orientation and density for bioactivity, providing a cheap and reproducible, one-step method for labeling NPs with globular targeting moieties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2021.02.031DOI Listing
June 2021

Biodegradable photoresponsive nanoparticles for chemo-, photothermal- and photodynamic therapy of ovarian cancer.

Mater Sci Eng C Mater Biol Appl 2020 Nov 17;116:111196. Epub 2020 Jun 17.

Laboratorio de Inmunología, Departamento de Fisiología, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara 44340, Mexico. Electronic address:

Ovarian cancer (OC) is the deadliest gynecological cancer. Standard treatment of OC is based on cytoreductive surgery followed by chemotherapy with platinum drugs and taxanes; however, innate and acquired drug-resistance is frequently observed followed by a relapse after treatment, thus, more efficient therapeutic approaches are required. Combination therapies involving phototherapies and chemotherapy (the so-called chemophototherapy) may have enhanced efficacy against cancer, by attacking cancer cells through different mechanisms, including DNA-damage and thermally driven cell membrane and cytoskeleton damage. We have designed and synthesized poly(lactic-co-glycolic) nanoparticles (PLGA NPs) containing the chemo-drug carboplatin (CP), and the near infrared (NIR) photosensitizer indocyanine green (ICG). We have evaluated the drug release profile, the photodynamic ROS generation and photothermal capacities of the NPs. Also, the antitumoral efficiency of the NPs was evaluated using the SKOV-3 cell line as an in vitro OC model, observing an enhanced cytotoxic effect when irradiating cells with an 800 nm laser. Evidence here shown supports the potential application of the biodegradable photoresponsive NPs in the clinical stage due to the biocompatibility of the materials used, the spatiotemporal control of the therapy and, also, the less likely development of resistance against the combinatorial therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.msec.2020.111196DOI Listing
November 2020

The -174G>C and -596G>A Polymorphisms Are Not Associated with Circulating IL-6 Levels in Breast Cancer Patients from Jalisco, México.

Genet Test Mol Biomarkers 2020 Apr 26;24(4):224-228. Epub 2020 Mar 26.

Laboratorio de Inmunología, Departamento de Fisiología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.

Interleukin-6 (IL-6) is a circulating proinflammatory cytokine that fulfills an important role in the survival and proliferation of cancer cells. Overexpression of IL-6, possibly due to the -174G>C and -596G>A polymorphisms in the gene, has been shown to be related to breast cancer (BC) and a more aggressive course of the disease. To determine the influence of the -174G>C and -596G>A polymorphisms of the gene on the circulating levels of IL-6 in BC patients from Jalisco, México. Genotyping of the two polymorphisms was carried out on 208 BC patients and 219 healthy controls through polymerase chain reaction-restriction fragment length polymorphism analyses. In addition, the plasma IL-6 concentration levels were measured in the BC patients. There was no significant association between BC and the alleles and genotypes (-174G>C,  = 0.276; -596G>A,  = 0.762) under study. Similarly, there were no significant differences in the mean plasma IL-6 concentrations associated with the polymorphisms that were analyzed (-174G>C,  = 0.839; -596G>A,  = 0.848). No evidence was found that the analyzed polymorphisms are associated with the IL-6 expression or concentration in patients suffering from BC from Jalisco, Mexico.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/gtmb.2019.0141DOI Listing
April 2020

Cisplatin-loaded PLGA nanoparticles for HER2 targeted ovarian cancer therapy.

Colloids Surf B Biointerfaces 2019 Jun 6;178:199-207. Epub 2019 Mar 6.

Laboratorio de Inmunología, Departamento de Fisiología, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, 44340, Mexico.

The conventional treatment (cytoreduction combined with cisplatin/carboplatin and taxane drugs) of ovarian cancer has a high rate of failure and recurrence despite a favorable initial response. This lack of success is usually attributed to the development of multidrug resistance mechanisms by cancer cells and avoidance of the anti-growth effects of monoclonal targeted therapeutic antibodies. The disease, like other cancers, is characterized by the overexpression of molecular markers, including HER2 receptors. Preclinical and clinical studies with trastuzumab, a HER2-targeted therapeutic antibody, reveal a low improvement of the outcomes of HER2 positive ovarian cancer patients. Therefore, here, we propose a cisplatin-loaded, HER2 targeted poly(lactic-co-glycolic) nanoplatform, a system capable to escape the drug-efflux effect and to take advantage of the overexpressed HER2 receptors, using them as docks for targeted chemotherapy. The NP/trastuzumab ratio was determined after fluorescein labeling of antibodies and quantification of fluorescence in NPs. The system was also characterized in terms of size, zeta potential, drug release kinetics, cytotoxicity and cellular internalization in the epithelial ovarian cancer cell line SKOV-3, and compared with the HER2 negative breast cancer cell line HCC70. Our results show an increased cytotoxicity of NPs as compared to free cisplatin, and moreover, an enhanced internalization and cytotoxicity due to the bionfunctionalization of NPs with the monoclonal antibody.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.colsurfb.2019.03.011DOI Listing
June 2019

Gold Nanorod-Based Nanohybrids for Combinatorial Therapeutics.

ACS Omega 2018 Oct 4;3(10):12633-12647. Epub 2018 Oct 4.

Grupo de Física de Coloides y Polímeros, Departamento de Física de Partículas, Facultad de Física e Instituto de Investigaciones Sanitarias (IDIS), Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.

In this work, multifunctional nanocarriers consisting of poly(sodium-4-styrenesulfonate) (PSS)/doxorubicin (DOXO)/poly-l-lysine hydrobromide (PLL)/hyaluronic acid (HA)-coated and (PSS/DOXO/PLL)/HA-coated gold nanorods were assembled by the layer-by-layer technique with the aims of coupling the plasmonic photothermal properties of the metal nanoparticles for plasmonic hyperthermia and the chemoaction of drug DOXO for potential intended combinatorial cancer therapeutics in the future as well as providing different strategies for the controlled and sustained release of the cargo drug molecules. To do that, DOXO could be successfully loaded onto the hybrid nanoconstructs through electrostatic interactions with high efficiencies of up to ca. 78.3 ± 6.9% for the first formed drug layer and 56 ± 13% for the second one, with a total efficiency for the whole system [(PSS/DOXO/PLL)/HA-coated NRs] of ca. 65.7 ± 1.4%. Nanohybrid internalization was observed to be enhanced by the outer HA layer, which is able to target the CD44 receptors widely overexpressed in some types of cancers as lung, breast, or ovarian ones. Hence, these nanohybrid systems might be versatile nanoplatforms to simultaneously deliver sufficient heat for therapeutic plasmonic hyperthermia and the anticancer drug. Two controlled mechanisms were proposed to modulate the release of the chemodrug, one by means of the enzymatic degradable character of the PLL layer and another by the modulation of the interactions between the polymeric layers through the exploitation of the optical properties of the hybrid particles under near infrared (NIR) laser irradiation. The combination of this bimodal therapeutic approach exerted a synergistic cytotoxic effect on both HeLa and MDA-MB-231 cancer cells in vitro. Cell death mechanisms were also analyzed, elucidating that plasmonic photothermal therapy induces cell necrosis, whereas DOXO activates the cell apoptotic pathway. Therefore, the present NIR laser-induced targeted cancer thermo/chemotherapy represents a novel targeted anticancer strategy with easy control on demand and suitable therapeutic efficacy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsomega.8b01591DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6217551PMC
October 2018

Rational Surface Engineering of Colloidal Drug Delivery Systems for Biological Applications.

Curr Top Med Chem 2018 ;18(14):1224-1241

Department of Physiology, Laboratory of Immunology, Health Sciences Centre (CUCS) University of Guadalajara, Guadalajara, 44340, Mexico.

The use of colloidal particles as drug delivery carriers holds a great promise in terms of improvement of traditional treatment and diagnosis of human diseases. Nano- and microsized particles of a different composition including organic and inorganic materials can be fabricated with a great control over size, shape and surface properties. Nevertheless, only some few formulations have surpassed the benchtop and reached the bedside. The principal obstacle of colloidal drug delivery systems is their poor accumulation in target tissues, organs and cells, mainly by efficient sequestration and elimination by the mononuclear phagocytic system. Recent evidence suggests that, besides size, the surface character of colloidal systems is the most determinant design parameter that may ultimately guarantee successful biological performance. To approach these issues, materials designers and engineers can make use of multiple strategies and tools to finely modulate the particles' surface towards highly efficient and biocompatible materials. In this article, we provide an overview of the most relevant colloidal drug delivery systems, a summary of the available literature regarding the effects of surface charge, hydrophobicity and softness on biological response, and finally, we review the key points of surface modification strategies with organic, inorganic and biological materials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2174/1568026618666180810145234DOI Listing
November 2018

Preparation of PLGA/Rose Bengal colloidal particles by double emulsion and layer-by-layer for breast cancer treatment.

J Colloid Interface Sci 2018 May 7;518:122-129. Epub 2018 Feb 7.

Laboratorio de Inmunología, Departamento de Fisiología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Sierra Mojada 950, Guadalajara, Jalisco 44340, Mexico. Electronic address:

The use of colloidal particles (CPs) in the transport of drugs is developing rapidly thanks to its effectiveness and biosafety, especially in the treatment of various types of cancer. In this study Rose Bengal/PLGA CPs synthesized by double emulsion (W/O/W) and by electrostatic adsorption (layer-by-layer), were characterized and evaluated as potential breast cancer treatment. CPs were evaluated in terms of size, zeta potential, drug release kinetics and cell viability inhibition efficacy with the triple negative breast cancer cell line HCC70. The results showed that both types of CPs can be an excellent alternative to conventional cancer treatment by taking advantage of the enhanced permeation and retention (EPR) effect, manifested by solid tumors; however, the double emulsion CPs showed more suitable delivery times of up to 60% within two days, while layer-by-layer showed fast release of 50% in 90 min. Both types of CPs were capable to decrease cell viability, which encourage us to further testing in in vivo models to prove their efficacy and feasible use in the treatment of triple negative breast cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2018.02.013DOI Listing
May 2018

Immobilization effects on the photocatalytic activity of CdS quantum Dots-Horseradish peroxidase hybrid nanomaterials.

J Colloid Interface Sci 2017 Nov 6;506:36-45. Epub 2017 Jul 6.

Departamento de Procesos y Tecnología, Unidad Cuajimalpa, Universidad Autónoma Metropolitana, Mexico City 05348, Mexico. Electronic address:

The potential use of hybrid nanomaterials based on inorganic optically active nanoparticles known as quantum dots (QDs) and horseradish peroxidase (HRP) has been proposed by several authors as light-controllable nanocatalyzers, moreover, the immobilization within or over silica based supports represents an advantage over bulk-dispersed systems. However, the implications of the immobilization of such hybrid photoactivatable catalyzing systems have not been clarified with detail. Here, we present a thorough study of the functional photoactive efficiency and recycling of immobilized CdS QDs and HRP systems with different configurations, immobilized over silanized silica quartz crystal microbalance (QCM) sensors, allowing an accurate measure of the immobilized mass of each component and its correlation with the initial reaction rate of conversion of Amplex Red (AR) to resorufin. As well, the conversion efficiency is compared between the different systems and also to non-immobilized QD-HRP complexed systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2017.07.015DOI Listing
November 2017

Intraarterial route increases the risk of cerebral lesions after mesenchymal cell administration in animal model of ischemia.

Sci Rep 2017 01 16;7:40758. Epub 2017 Jan 16.

Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.

Mesenchymal stem cells (MSCs) are a promising clinical therapy for ischemic stroke. However, critical parameters, such as the most effective administration route, remain unclear. Intravenous (i.v.) and intraarterial (i.a.) delivery routes have yielded varied outcomes across studies, potentially due to the unknown MSCs distribution. We investigated whether MSCs reached the brain following i.a. or i.v. administration after transient cerebral ischemia in rats, and evaluated the therapeutic effects of both routes. MSCs were labeled with dextran-coated superparamagnetic nanoparticles for magnetic resonance imaging (MRI) cell tracking, transmission electron microscopy and immunohistological analysis. MSCs were found in the brain following i.a. but not i.v. administration. However, the i.a. route increased the risk of cerebral lesions and did not improve functional recovery. The i.v. delivery is safe but MCS do not reach the brain tissue, implying that treatment benefits observed for this route are not attributable to brain MCS engrafting after stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep40758DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5238501PMC
January 2017

Easy and Efficient Cell Tagging with Block Copolymer-Based Contrast Agents for Sensitive MRI Detection in Vivo.

Cell Transplant 2016 10;25(10):1787-1800

Clinical Neurosciences Research Laboratory, Clinical University Hospital, Health Research Institute of Santiago de Compostela (IDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.

Superparamagnetic iron oxide nanoparticles (MNPs) together with magnetic resonance imaging (MRI) are the preferred tools for monitoring the fate and biodistribution of administered cells in stem cell therapy studies. Commercial MNPs need transfection agents and long incubation times for sufficient cell labeling and further in vivo cell detection. In this work, we have synthesized MNPs coated with pluronic F127 and tetronic 908, and validated their applicability as contrast agents for MRI cell detection on two different cell types: rat mesenchymal stem cells (MSCs) and multipotent neural progenitor cell line from mice (C17.2). No transfection agent was needed for a complete MNP internalization, and the uptake was only dependent on MNP concentration in medium and limited on the incubation time. By combining in vivo MRI and ex vivo histology microscopy, we have demonstrated the MRI signal detected corresponded exclusively to labeled cells and not to free particles. Pluronic F127- and tetronic 908-coated MNPs represent promising contrast agents for stem cell tracking due to their ease of use in preparation, their efficiency for cell labeling, and their high sensitivity for in vivo cell detection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3727/096368916X691303DOI Listing
October 2016

Simple control of surface topography of gold nanoshells by a surfactant-less seeded-growth method.

ACS Appl Mater Interfaces 2014 Jul 8;6(14):11142-57. Epub 2014 Jul 8.

Grupo de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela , Santiago de Compostela 15782, Spain.

We report the synthesis of branched gold nanoshells (BGNS) through a seeded-growth surfactant-less method. This was achieved by decorating chitosan-Pluronic F127 stabilized poly(lactic-co-gycolic) acid nanoparticles (NPs) with Au seeds (NP-seed), using chitosan as an electrostatic self-assembling agent. Branched shells with different degrees of anisotropy and optical response were obtained by modulating the ratios of HAuCl4/K2CO3 growth solution, ascorbic acid (AA) and NP-seed precursor. Chitosan and AA were crucial in determining the BGNS size and structure, acting both as coreductants and structure directing growth agents. Preliminary cytotoxicity experiments point to the biocompatibility of the obtained BGNS, allowing their potential use in biomedical applications. In particular, these nanostructures with "hybrid" compositions, which combine the features of gold nanoshells and nanostars showed a better performance as surface enhanced Raman spectroscopy probes in detecting intracellular cell components than classical smoother nanoshells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/am500989eDOI Listing
July 2014

Polymeric-gold nanohybrids for combined imaging and cancer therapy.

Adv Healthc Mater 2014 Aug 25;3(8):1309-25. Epub 2014 Apr 25.

Grupo de Física de Coloides y Polímeros, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain.

Here, the use of folic acid (FA)-functionalized, doxorubicin (DOXO)/superparamagnetic iron oxide nanoparticles (SPION)-loaded poly(lactic-co-glycolic acid) (PLGA)-Au porous shell nanoparticles (NPs) as potential nanoplatforms is reported for targeted multimodal chemo- and photothermal therapy combined with optical and magnetic resonance imaging in cancer. These polymeric-gold nanohybrids (PGNH) are produced by a seeded-growth method using chitosan as an electrostatic "glue" to attach Au seeds to DOXO/SPION-PLGA NPs. In order to determine their potential as theranostic nanoplatforms, their physicochemical properties, cellular uptake, and photothermal and chemotherapeutic efficiencies are tested in vitro using a human cervical cancer (HeLa) cell line. The present NPs show a near-infrared (NIR)-light-triggered release of cargo molecules under illumination and a great capacity to induce localized cell death in a well-focused region. The functionalization of the PGNH NPs with the targeting ligand FA improves their internalization efficiency and specificity. Furthermore, the possibility to guide the PGNH NPs to cancer cells by an external magnetic field is also proven in vitro, which additionally increases the cellular uptake and therapeutic efficiency.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/adhm.201400023DOI Listing
August 2014

Fluorescent drug-loaded, polymeric-based, branched gold nanoshells for localized multimodal therapy and imaging of tumoral cells.

ACS Nano 2014 Mar 3;8(3):2725-38. Epub 2014 Mar 3.

Grupo de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela , Santiago de Compostela 15782, Spain.

Here we report the synthesis of PLGA/DOXO-core Au-branched shell nanostructures (BGNSHs) functionalized with a human serum albumin/indocyanine green/folic acid complex (HSA-ICG-FA) to configure a multifunctional nanotheranostic platform. First, branched gold nanoshells (BGNSHs) were obtained through a seeded-growth surfactant-less method. These BGNSHs were loaded during the synthetic process with the chemotherapeutic drug doxorubicin, a DNA intercalating agent and topoisomerase II inhibitior. In parallel, the fluorescent near-infrared (NIR) dye indocyanine green (ICG) was conjugated to the protein human serum albumin (HSA) by electrostatic and hydrophobic interactions. Subsequently, folic acid was covalently attached to the HSA-ICG complex. In this way, we created a protein complex with targeting specificity and fluorescent imaging capability. The resulting HSA-ICG-FA complex was adsorbed to the gold nanostructures surface (BGNSH-HSA-ICG-FA) in a straightforward incubation process thanks to the high affinity of HSA to gold surface. In this manner, BGNSH-HSA-ICG-FA platforms were featured with multifunctional abilities: the possibility of fluorescence imaging for diagnosis and therapy monitoring by exploiting the inherent fluorescence of the dye, and a multimodal therapy approach consisting of the simultaneous combination of chemotherapy, provided by the loaded drug, and the potential cytotoxic effect of photodynamic and photothermal therapies provided by the dye and the gold nanolayer of the hybrid structure, respectively, upon NIR light irradiation of suitable wavelength. The combination of this trimodal approach was observed to exert a synergistic effect on the cytotoxicity of tumoral cells in vitro. Furthermore, FA was proved to enhance the internalization of nanoplatform. The ability of the nanoplatforms as fluorescence imaging contrast agents was tested by preliminary analyzing their biodistribution in vivo in a tumor-bearing mice model.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/nn406425hDOI Listing
March 2014

Micellisation of triblock copolymers of ethylene oxide and 1,2-butylene oxide: effect of B-block length.

J Colloid Interface Sci 2011 Sep 24;361(1):154-8. Epub 2011 May 24.

Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, Spain.

We have used pyrene fluorescence spectroscopy and isothermal titration calorimetry (ITC) to investigate the effect of hydrophobic-block length on values of the critical micelle concentration (cmc) for aqueous solutions of triblock poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) block copolymers (B(n)E(m)B(n), where m and n denote the respective block lengths) with hydrophobic block lengths in the range n=12-21. Combined with results from previous work on B(n)E(m)B(n) copolymers with shorter B blocks, plots of log(10)(cmc) (cmc in molar units and reduced to a common E-block length) against total number of B units (n(t)=n for diblock or n(t)=2n for triblock copolymers) display transitions in the slopes of the two plots, which indicate changes in the micellisation equilibrium. These occur at values of n(t)which can be assigned to the onset and completion of collapse of the hydrophobic B blocks, an effect not previously observed for reverse triblock copolymers. The results are compared with related data for diblock E(m)B(n) copolymers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcis.2011.05.059DOI Listing
September 2011

One-dimensional magnetic nanowires obtained by protein fibril biotemplating.

Chemistry 2011 Jun 6;17(26):7366-73. Epub 2011 May 6.

Grupo de Física de Coloides y Polímeros, Departamento de Física de la Materia Condensada, Facultad de Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.

Magnetic nanowires were obtained through the in situ synthesis of magnetic material by Fe-controlled nanoprecipitation in the presence of two different protein (human serum albumin (HSA) and lysozyme (Lys)) fibrils as biotemplating agents. The structural characteristics of the biotemplates were transferred to the hybrid magnetic wires. They exhibited excellent magnetic properties as a consequence of the 1D assembly and fusion of magnetite nanoparticles as ascertained by SQUID magnetometry. Prompted by these findings, we also checked their potential applicability as MRI contrast agents. The magnetic wires exhibited large r(2)* relaxivities and sufficient contrast resolution even in the presence of an extremely small amount of Fe in the magnetic hybrids, which would potentially enable their use as T(2) contrast imaging agents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.201003679DOI Listing
June 2011