Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
ChemistrySelect ; 6(31): 7931-7935, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34541297

RESUMEN

Iron oxide magnetic nanoparticles have been employed as potential vehicles for a large number of biomedical applications, such as drug delivery. This article describes the synthesis, characterization and in vitro cytotoxic in COVID-19 cells evaluation of DMSA superparamagnetic iron oxide magnetic nanoparticles. Magnetite (Fe3O4) nanoparticles were synthesized by co-precipitation of iron salts and coated with meso-2,3-dimercaptosuccinic acid (DMSA) molecule. Structural and morphological characterizations were performed by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR), magnetic measurements (SQUID), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Our results demonstrate that the nanoparticles have a mean diameter of 12 nm in the solid-state and are superparamagnetic at room temperature. There is no toxicity of SPIONS-DMSA under the cells of patients with COVID-19. Taken together the results show that DMSA- Fe3O4 are good candidates as nanocarriers in the alternative treatment of studied cells.

2.
Mater Sci Eng C Mater Biol Appl ; 99: 171-179, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30889689

RESUMEN

This article describes the synthesis, characterization and in vivo cytotoxic evaluation of thiol-functionalized superparamagnetic iron oxide magnetic nanoparticles (SPIONs). They have been employed as potential vehicles for a large number of biomedical applications, such as drug delivery. Fe3O4 nanoparticles were synthesized by coprecipitation of iron salts and coated with L-cysteine. The physicochemical, morphological, and magnetic properties of Cys-Fe3O4 nanoparticles were characterized by different experimental techniques. To evaluate their applicability in nanomedicine we evaluated their cytotoxicity using Balb/C mice. The results show that Cys-SPIONs are good candidates as nanocarriers in biomedical applications.


Asunto(s)
Nanopartículas de Magnetita/química , Compuestos de Sulfhidrilo/química , Animales , Cistina/química , Hidrodinámica , Hierro/sangre , Nanopartículas de Magnetita/ultraestructura , Masculino , Ratones Endogámicos BALB C , Tamaño de la Partícula , Espectroscopía Infrarroja por Transformada de Fourier , Bazo/metabolismo , Electricidad Estática , Difracción de Rayos X
3.
J Environ Manage ; 230: 405-412, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30296678

RESUMEN

Oil spill is a serious environmental concern, and alternatives to remove oils from water involving biosorbents associated to nanoparticles is an emerging subject. Magnetite nanoparticles (MNP) and yeast magnetic bionanocomposite (YB-MNP) composed by yeast biomass from the ethanol industry were produced, characterized, and tested to remove new motor oil (NMO), mixed used motor oil (MUMO) and Petroleum 28 °API (P28API) from water following the ASTM F726-12 method, which was adapted by insertion of a lyophilization step to ensure the accuracy of the gravimetric approach. Temperature, contact time, the type and the amount of the magnetic material were the parameters evaluated employing a fractional factorial design. It was observed the removal of 89.0 ±â€¯2.6% or 3522 ±â€¯118 g/kg (NMO) employing MNP; 69.1 ±â€¯6.2% or 2841 ±â€¯280 g/kg (MUMO) with YB-MNP; and 55.3 ±â€¯8.2% or 2157 ±â€¯281 g/kg (P28API) using MNP. The temperature was the most significant parameter in accordance with the Pareto's graphics (95% confidence) for all oil samples considered in this study as well as the two magnetic materials. Contact time and the interaction between the materials and temperature were also relevant. The D-Optimals designs showed that the NMO and P28API responded in a similar way for all evaluated parameters, while the uptake of MUMO was favored at higher temperatures. These behaviors demonstrate the influence of oil characteristics and the intermolecular forces between the oil molecules on the mechanism dragging process performed by the attraction between magnetite nanoparticles and a 0.7 T magnet. It was clear that this kind of experiment is predominantly a physic phenomenon which cannot be described as adsorption process.


Asunto(s)
Nanopartículas de Magnetita , Contaminación por Petróleo/análisis , Petróleo , Adsorción , Biomasa , Temperatura
4.
J Nanosci Nanotechnol ; 17(1): 133-42, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29617094

RESUMEN

Superparamagnetic iron oxide nanoparticles (SPIONs), with appropriate surface coating, are commonly used for biomedical applications such as photodynamic therapy (PDT). This work describes the preparation and characterization of methylene blue (MB)-containing silica-coated SPIONs. Upon exposure to light, MB reacts with molecular oxygen and generates singlet oxygen (1O2) which is cytotoxic and causes irreversible damage to tumor tissues. In this work, SPIONs were synthesized by co-precipitation and coated with a single/double silica layer. The photoactive molecule MB was entrapped in the silica layer deposited on the surface of SPIONs, leading to the formation of hybrid nanomaterials composed of a magnetic core and silica layer. The nanocomposite exhibited magnetic behavior at room temperature due to the presence of its Fe3O4 core. Structural and morphological characterizations were performed by X-ray diffraction (XRD), Fourier transformed infrared (FTIR), SQUID magnetic measurements, ultraviolet-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and dynamic light scattering. The results showed the presence of a crystalline Fe3O4 magnetic core and amorphous silica phases. Kinetic measurements revealed 1O2 generation by the nanoparticles upon irradiation with visible light (λ = 532 nm or λ = 633 nm). The results highlight the potential uses of SPIONs coated with MB-entrapped silica for PDT, whereby a sustained and localized generation of 1O2 was successfully achieved.

5.
Biotechnol Adv ; 33(6 Pt 3): 1370-9, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25636971

RESUMEN

Recently, an increasing number of publications have demonstrated the importance of the small molecule nitric oxide (NO) in several physiological and pathophysiological processes. NO acts as a key modulator in cardiovascular, immunological, neurological, and respiratory systems, and deficiencies in the production of NO or its inactivation has been associated with several pathologic conditions, ranging from hypertension to sexual dysfunction. Although the clinical administration of NO is still a challenge owing to its transient chemical nature, the combination of NO and nanocarriers based on biocompatible polymeric scaffolds has emerged as an efficient approach to overcome the difficulties associated with the biomedical administration of NO. Indeed, significant progress has been achieved by designing NO-releasing polymeric nanomaterials able to promote the spatiotemporal generation of physiologically relevant amounts of NO in diverse pharmacological applications. In this review, we summarize the recent advances in the preparation of versatile NO-releasing nanocarriers based on polymeric nanoparticles, dendrimers and micelles. Despite the significant innovative progress achieved using nanomaterials to tailor NO release, certain drawbacks still need to be overcome to successfully translate these research innovations into clinical applications. In this regard, this review discusses the state of the art regarding the preparation of innovative NO-releasing polymeric nanomaterials, their impact in the biological field and the challenges that need to be overcome. We hope to inspire new research in this exciting area based on NO and nanotechnology.


Asunto(s)
Nanoestructuras/química , Óxido Nítrico/administración & dosificación , Óxido Nítrico/metabolismo , Polímeros/química , Animales , Dendrímeros/química , Dendrímeros/farmacología , Diseño de Fármacos , Humanos , Micelas , Nanopartículas/administración & dosificación , Nanopartículas/química , Nanoestructuras/administración & dosificación , Nanotecnología , Donantes de Óxido Nítrico/química , Donantes de Óxido Nítrico/farmacología , Polímeros/farmacología
6.
Chem Res Toxicol ; 27(7): 1207-18, 2014 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-24949992

RESUMEN

Iron oxide magnetic nanoparticles have been proposed for an increasing number of biomedical applications, such as drug delivery. To this end, toxicological studies of their potent effects in biological media must be better evaluated. The aim of this study was to synthesize, characterize, and examine the potential in vitro cytotoxicity and genotoxicity of thiolated (SH) and S-nitrosated (S-NO) iron oxide superparamagnetic nanoparticles toward healthy and cancer cell lines. Fe3O4 nanoparticles were synthesized by coprecipitation techniques and coated with small thiol-containing molecules, such as mercaptosuccinic acid (MSA) or meso-2,3-dimercaptosuccinic acid (DMSA). The physical-chemical, morphological, and magnetic properties of thiol-coating Fe3O4 nanoparticles were characterized by different techniques. The thiol groups on the surface of the nanoparticles were nitrosated, leading to the formation of S-nitroso-MSA- or S-nitroso-DMSA-Fe3O4 nanoparticles. The cytotoxicity and genotoxicity of thiolated and S-nitrosated nanoparticles were more deeply evaluated in healthy (3T3, human lymphocytes cells, and chinese hamster ovary cells) and cancer cell lines (MCF-7). The results demonstrated that thiol-coating iron oxide magnetic nanoparticles have few toxic effects in cells, whereas S-nitrosated-coated particles did cause toxic effects. Moreover, due to the superaramagnetic behavior of S-nitroso-Fe3O4 nanoparticles, those particles can be guided to the target site upon the application of an external magnetic field, leading to local toxic effects in the tumor cells. Taken together, the results suggest the promise of S-nitroso-magnetic nanoparticles in cancer treatment.


Asunto(s)
Antineoplásicos/toxicidad , Nanopartículas de Magnetita/toxicidad , Células 3T3 , Animales , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Células CHO , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ensayo Cometa , Cricetinae , Cricetulus , Humanos , Linfocitos/efectos de los fármacos , Células MCF-7 , Fenómenos Magnéticos , Nanopartículas de Magnetita/química , Ratones , Neoplasias/tratamiento farmacológico , Nitrosación , Nitrito de Sodio/química , Succímero/química , Tiomalatos/química
7.
Mater Sci Eng C Mater Biol Appl ; 33(2): 746-51, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25427482

RESUMEN

This work reports a new strategy for delivering nitric oxide (NO), based on magnetic nanoparticles (MNPs), with great potential for biomedical applications. Water-soluble magnetic nanoparticles were prepared through a co-precipitation method by using ferrous and ferric chlorides in acidic solution, followed by a mercaptosuccinic acid (MSA) coating. The thiolated nanoparticles (SH-NPs) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results showed that the SH-NPs have a mean diameter of 10nm and display superparamagnetic behavior at room temperature. Free thiol groups on the magnetite surface were nitrosated through the addition of an acidified nitrite solution, yielding nitrosated magnetic nanoparticles (SNO-NPs). The amount of NO covalently bound to the nanoparticles surface was evaluated by chemiluminescense. The SNO-NPs spontaneously released NO in aqueous solution at levels required for biomedical applications. This new magnetic NO-delivery vehicle has a great potential to generate desired amounts of NO directed to the target location.


Asunto(s)
Compuestos Férricos/química , Nanopartículas de Magnetita/química , Donantes de Óxido Nítrico/química , Adsorción , Cinética , Microscopía Electrónica de Transmisión , Nitritos/química , Nitritos/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Tiomalatos/química , Difracción de Rayos X
8.
J Colloid Interface Sci ; 339(2): 344-50, 2009 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-19712937

RESUMEN

The relationship between crystallization and growth of colloidal iron oxide nanoparticles during isothermal annealing was addressed in this work. The structural, morphological and chemical modifications of the nanoparticles during thermal treatments were followed by combination of electron microscopy, X-ray diffraction and spectroscopic methods. The initially monodisperse spherical nanoparticles with amorphous and partially oxidized structure evolved during the treatments, depending on the temperature and treatment time. Core-void-shell nanoparticles or single crystal nanoparticles and hollow polycrystalline nanoparticles, both with well defined Fe(3)O(4) oxide phase, are formed depending on the conditions. This evolution was interpreted as a result of the Kirkendall effect associated to mass redistribution and fragmentation of the nanoparticles, bringing new information about the effect of post-synthesis treatments on the crystallinity and morphology of colloidal nanoparticles.

9.
Langmuir ; 23(3): 1307-14, 2007 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-17241051

RESUMEN

We study the photodecomposition of phospholipid bilayers in aqueous solutions of methylene blue. Observation of giant unilamellar vesicles under an optical microscope reveals a consistent pattern of membrane disruption as a function of methylene blue concentration and photon density for different substrates supporting the vesicles.


Asunto(s)
Membrana Dobles de Lípidos/efectos de la radiación , Liposomas/efectos de la radiación , Fotoquímica , Azul de Metileno , Fosfolípidos , Soluciones
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...