Preparation and size-modulation of silica-coated maghemite nanoparticles

Almeida, M.P.S. de; Caiado, Kely Lopes; Sartoratto, P.P.C.; Silva, D.O. Cintra e; Pereira, A.R.; Morais, P.C.

doi:10.1016/j.jallcom.2009.10.245

Cited by 24 publications

(16 citation statements)

References 21 publications

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“…Another factor might be the comparably smaller silane amount, which is not enough to efficiently form and stabilize single core shell nanoparticles. As described by Almeida et al [26], the hydrolyzed and partially condensed silane molecules deposit on the individual or aggregated SPIONs. These small hybrid particles aggregate randomly at low TEOS concentration and so, a uniform growth of silica cannot occur.…”

Section: Influence Of the Silica/spions Ratios On Morphologymentioning

confidence: 86%

“…Silica coating is usually achieved by two synthetic routes: the Stöber [23] process or the microemulsion process [24]. In general, single core-shell particles are obtained by the latter, whereas the Stöber process results in multicore/shell particles [25][26][27], which are particularly interesting for magnetic separation technologies [28]. Organosilanes are abundantly used for their simplicity of grafting onto SPIONs [3] and, depending on the chemical nature of the functional group, their ability to introduce new ligands and therefore properties to the SPIONs [29,30].…”

mentioning

confidence: 99%

“…Since condensation of APTES on SPIONs was reported to result in agglomeration of the particles into small clusters [31], many studies [32] have focused on a two-step approach, where SPIONs are first coated with silica using tetraethyl orthosilicate (TEOS), followed by a second hydrolysis/condensation step using APTES [26,33]. However, up to now, no detailed study about the controlled synthesis of silica hybrid magnetic nanoparticles via co-condensation of APTES and TEOS on SPIONs has been proposed.…”

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confidence: 99%

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Preparation and characterization of functional silica hybrid magnetic nanoparticles

Digigow

Dechézelles

Dietsch

et al. 2014

Journal of Magnetism and Magnetic Materials

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We report on the synthesis and characterization of functional silica hybrid magnetic nanoparticles (SHMNPs). The co-condensation of 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate (TEOS) in presence of superparamagnetic iron oxide nanoparticles (SPIONs) leads to hybrid magnetic silica particles that are surface-functionalized with primary amino groups. In this work, a comprehensive synthetic study is carried out and completed by a detailed characterization of hybrid particles' size and morphology, surface properties, and magnetic responses using different techniques. Depending on the mass ratio of SPIONs and the two silanes (TEOS and APTES), we were able to adjust the number of surface amino groups and tune the magnetic properties of the superparamagnetic hybrid particles.

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Section: Influence Of the Silica/spions Ratios On Morphologymentioning

confidence: 86%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Preparation and characterization of functional silica hybrid magnetic nanoparticles

Digigow

Dechézelles

Dietsch

et al. 2014

Journal of Magnetism and Magnetic Materials

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“…• Cover of magnetic nanoparticles with organic compounds, including surfactants [84][85][86][87] and polymers [88][89][90][91]; • Coating of magnetic nanoparticles with inorganic compounds, including silica gel [92][93][94], carbon [95,96], and precious metals (Au [97,98], Ag [99]). …”

Section: Stabilization/functioning Of Magnetic Nanoparticlesmentioning

confidence: 99%

“…Many studies described the role of functional groups, which control reactivity and colloidal properties of magnetic suspension, as well as the influence of alkaline reagents, concentration of coated nanoparticles, water/alcohol ratio, or concentration of TEOS on final morphological aspect of these nanostructures [92,93,112,113].…”

Section: Stabilization/functioning Of Magnetic Nanoparticlesmentioning

confidence: 99%

Pros and Cons on Magnetic Nanoparticles Use in Biomedicine and Biotechnologies Applications

Bojin

Păunescu

2014

Nanoparticles' Promises and Risks

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In recent years, the design and synthesis of colloidal magnetic suspensions have attracted an increased interest especially in the fields of biotechnology and biomedicine because they have many applications including targeted drug delivery, cell labeling and magnetic cell separation, hyperthermia, tissue repairing, magnetic resonance imaging (MRI) contrast enhancement, enzyme immobilization, immunoassays, protein purification, etc. IntroductionMagnetic nanoparticles (MNPs) used in biomedicine must meet several requirements. They have to be non-toxic, chemically stabile, uniform in size, well stabilized under physiological conditions, biocompatible and to present high magnetization. Magnetite (Fe 3 O 4 ) and maghemite (γ-Fe 2 O 3 ) are the most suitable iron oxide nanoparticles employed for biomedical applications because they are biocompatible, have low toxicity in the human body and show a superparamagnetic behavior.Therefore, synthesis of magnetic iron oxide nanoparticles with tailored properties has attracted considerable scientific and technological interest. Various synthesis routes were developed for producing magnetic particles, such as co-precipitation, microemulsion method, thermal decomposition of different organic precursors, spray pyrolysis, and sol-gel method.For biomedical applications, magnetic iron oxide nanoparticles must be dispersed in biocompatible media in order to obtain stable colloidal suspensions. In order to prevent the particle aggregation and to improve the biocompatibility and stability, nanoparticles are coated with various surfactants: poly(ethylene glycol),

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The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

2015

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In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating of PEG reduced the wrapping of the protein corona around the nanoparticles. This phenomenon caused increase in Dox release.

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Preparation and size-modulation of silica-coated maghemite nanoparticles

Cited by 24 publications

References 21 publications

Preparation and characterization of functional silica hybrid magnetic nanoparticles

Preparation and characterization of functional silica hybrid magnetic nanoparticles

Pros and Cons on Magnetic Nanoparticles Use in Biomedicine and Biotechnologies Applications

The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

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