Preparation and characterization of ultra-stable biocompatible magnetic fluids using citrate-coated cobalt ferrite nanoparticles

Morais, P.C.; Santos, Roberto de Souza; Pimenta, A.C.M.; Azevedo, Ricardo Bentes; Lima, E.C.D.

doi:10.1016/j.tsf.2005.12.079

Cited by 92 publications

(56 citation statements)

References 19 publications

(14 reference statements)

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“…CA can prevent the aggregation of magnetic particles effectively owning to the steric and electrostatic repulsive barrier of the ionized layer of citrate coating on magnetite or maghemite [19][20][21][22][23][24]. In general, empirical doses, sometimes huge amounts [19,20,24] are simply added to magnetite just after precipitating nanoparticles.…”

Section: Humate and Citrate Adsorption On Magnetite Nanoparticlesmentioning

confidence: 99%

Surface charging, polyanionic coating and colloid stability of magnetite nanoparticles

Hajdú

Illés

Tombácz

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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a b s t r a c tThe formation of small and large molecular polyanionic coating on the surface of magnetite (Fe 3 O 4 ) nanoparticles and their role in the stability enhancement of aqueous magnetic fluids are compared. Magnetite was synthesized and stabilized with citric (CA) and humic (HA) acids. The macromolecular HA, a notable fraction of the natural organic matter (NOM), contains mainly carboxylic groups similarly to the CA, and both acids are able to form surface complexes on the ≡Fe-OH sites of iron oxides. The pHdependent charge state of particles and their aggregation were quantified, and the enhanced salt tolerance of stabilized systems was studied. The dynamic light scattering (DLS) method was used to characterize colloidal stability under different conditions. The average particle size and electrophoretic mobility were measured, and the electrolyte tolerance was tested in coagulation kinetic measurements. The colloidal stability of magnetite dispersions depends sensitively on the pH and the concentration of organic acids present. The trace amount of HA neutralizes the positive charges on magnetite surface under acidic condition only in part, and so it promotes the aggregation between the particles having both positive sites and negative humate patches on the surface. Above the adsorption saturation, the surface becomes completely covered causing the reversal of charge sign and overcharging of nanoparticles. The magnetite nanoparticles become stabilized in a way of combined steric and electrostatic effects. The thicker layer of macromolecular HA provides better electrosteric stability than that of CA coating. However, in the presence of either CA or HA, the dissolution of magnetite is enhanced due to the complexation of iron ions in the aqueous medium.

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Section: Humate and Citrate Adsorption On Magnetite Nanoparticlesmentioning

confidence: 99%

Surface charging, polyanionic coating and colloid stability of magnetite nanoparticles

Hajdú

Illés

Tombácz

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…Modulation of the citrate surface-grafting onto cobalt ferrite nanoparticles was successfully achieved by varying the pH of the solution the bare particles were treated with [77]. Meso-2,3-dimercaptosuccinic acid (DMSA) has been used for surface-functionalization of bare maghemite nanoparticles at increasing surface-grafting values, revealing a rich scenario of interparticle and intra-particle linking via disulfide bridges resulting from the oxidation of neighboring thiol groups [78].…”

Section: Nanoparticle-based Hyperthermiamentioning

confidence: 99%

Remote Hyperthermia, Drug Delivery and Thermometry: The Multifunctional Platform Provided by Nanoparticles

Qi¹,

Morais

2014

J Nanomed Nanotechno

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The huge demand for biocompatible, robust, accurate and noninvasive technology to assess the temperature of a biological targeted site for monitoring the hyperthermia effect brings the topic of remote thermometry to a very high level of interest. There are already promising research directions to fulfil such demand in the short term and a review of the achievements in this issue is certainly worth. This report offers an overview of the research regarding the most promising nanothermometers nowadays, with emphasis on those addressed to remote operation while using optical or magnetic responses of nanosized materials as the thermometric property. More specifically the optical emission intensity, optical emission peak shift and optical emission lifetime will be covered as far as the optical-based nanothermometers are concerned. Additionally, for the magnetic-based nanothermometers the magnetization or the magnetic susceptibility are the thermometric properties covered in this review. Furthermore, the review includes the hyperthermia effect based on nanosized metallic or magnetic particles plus a couple of thermally-responsive polymeric drug delivery systems, aiming to provide an integrated view of the multipurpose platform offered by actuating-sensing nanoparticles. As far as the regulatory system is concerned the availability of noninvasive thermometry incorporating biocompatibility, robustness and accuracy will establish the grounds needed for the approval of the hyperthermia technology for therapeutic purposes, thus allowing the market of this technological option on a global scale.hyperthermia and thermoresponsive drug delivery systems for clinical use.Although nanothermometry is at its infancy considerable progress has been made recently in regard to its use for remote assessing the temperature at the site the nanomaterials are incorporated to. Nanoprobes allowing remote temperature-sensing using optical or magnetic properties are among the most promising directions nowadays. Most of the optical-based nanothermometers use the light-emitting intensity [15][16][17][18][19][20][21][22][23], light-emitting peak shift [24][25][26], or lifetime decay of a suitable optical band as the thermometric property [27][28][29][30]. As far as the clinical use is concerned the drawbacks of the actual optical-based nanothermometers rely on biocompatibility (usual semiconductor-based core nanoprobes or dye-based shell moieties are toxic), robustness (typical bleaching of organic-based shell moieties) or temperature accuracy (no better than 0.3°C nowadays), or even combination of these factors. Moreover, due to limitations imposed by living tissues on the optical penetration of light (optical therapeutic window in the 700-1100 nm wavelength range), noninvasive clinical use of optical excitation and signal pickup is a huge challenge, not yet solved, except for very special therapeutic applications, as for instance the photodynamic therapy for treatment (heating monitoring) of skin cancer and follow up [31]. Alternatively, ...

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“…Magnetic fluids incorporating biocompatible characteristics can be used as contrast agents for magnetic resonance imaging, drug carrier and delivery, local hyperthermia effect, etc. Typical biocompatible magnetic fluids consist of iron-containing magnetic nanoparticles [1][2][3], thus allowing Mössbauer spectroscopy to be used as an important investigation tool which has been very useful in various biomedical research [4][5][6]. There are various applications of Mössbauer spectroscopy including the study of magnetic nanoparticles for magnetic fluid development (see, for instance [7]).…”

Section: Introductionmentioning

confidence: 99%

Comparative study of iron oxide nanoparticles as-prepared and dispersed in Copaiba oil using Mössbauer spectroscopy with low and high velocity resolution

Оштрах

Šepelák

Rodriguez

et al. 2013

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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a b s t r a c tIron oxide nanoparticles, probably magnetite, as-prepared and dispersed in Copaiba oil were studied by Mössbauer spectroscopy using two different spectrometers: with a low velocity resolution (512 channels) for measurements at 295 and 21 K and with a high velocity resolution (4096 channels) for measurements at 295 and 90 K. The fitting of all measured spectra demonstrated that usual models applied to fit Möss-bauer spectra of magnetite and maghemite particles were not suitable. Therefore, the recorded spectra were fitted using a large number of spectral components on the basis of better quality of the fit and linearity of differential spectra. The number of components obtained for the better fit appeared to be different for spectra measured with a low and a high velocity resolution. However, these results demonstrated differences of Mössbauer parameters for iron oxide nanoparticles as-prepared and dispersed in Copaiba oil at applied temperatures. The effect of Copaiba oil molecules on Mössbauer parameters may be a result of the interactions of polar molecules such as kaurinic acid with nanoparticles' surface.

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Preparation and characterization of ultra-stable biocompatible magnetic fluids using citrate-coated cobalt ferrite nanoparticles

Cited by 92 publications

References 19 publications

Surface charging, polyanionic coating and colloid stability of magnetite nanoparticles

Surface charging, polyanionic coating and colloid stability of magnetite nanoparticles

Remote Hyperthermia, Drug Delivery and Thermometry: The Multifunctional Platform Provided by Nanoparticles

Comparative study of iron oxide nanoparticles as-prepared and dispersed in Copaiba oil using Mössbauer spectroscopy with low and high velocity resolution

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