RESUMEN
We present the new promising nanostructure- sandwich-like mesoporous silica nanoflakes synthesized on graphene oxide sheets core. In the first step biocompatibility of the nanoflakes with PEG and without functionalization in human fibroblast, melanoma and breast cancer cells was assessed. In order to define the cellular uptake in vitro and biodistribution in vivo the nanostructures were labelled with fluorescent dye. In the next step, the silica nanostructures were filled by the anticancer drug- methotrexate (MTX) and cytotoxicity of the complex in reference to MTX was evaluated. The WST-1 assay shows mild, but concentration dependent, cytotoxicity of the nanoflakes, most significant for the non-functionalized structures. PEG-modified silica nanoflakes didn't produce a disruption of cell membranes and lactate dehydrogenase (LDH) release. Cell imaging revealed efficient internalization of the silica nanoflakes in cells. Ex vivo organ imaging showed high accumulation of the nanostructures in lungs, bladder and gall bladder, whereas confocal imaging revealed wide nanoflake distribution in all tested tissues, especially at 1h and 4h post intravenous injection. Cytotoxicity of the nanoflake-MTX complex in reference to MTX showed similar cytotoxic potential against cancer cells. These findings may provide useful information for designing drug delivery systems, which may improve anticancer efficacy and decrease side effects.
Asunto(s)
Antimetabolitos Antineoplásicos/administración & dosificación , Sistemas de Liberación de Medicamentos , Metotrexato/administración & dosificación , Nanoestructuras , Animales , Antimetabolitos Antineoplásicos/farmacocinética , Antimetabolitos Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Química Farmacéutica/métodos , Femenino , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Inyecciones Intravenosas , Masculino , Melanoma/tratamiento farmacológico , Metotrexato/farmacocinética , Metotrexato/farmacología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Polietilenglicoles/química , Porosidad , Dióxido de Silicio/química , Distribución TisularRESUMEN
The properties of mesoporous silica nanoparticles including large surface area, large pore volume, easy surface functionalization and control of structure and pore size has made them promising drug carriers. In this study, the effect of different diameters (50 nm, 70 nm, 90 nm, 110 nm and 140 nm) of silica nanospheres with a solid core and mesoporous shell (mSiO2/SiO2) on cellular internalization in mouse fibroblast cells (L929) was evaluated. The physical properties of the nanostructures were characterized with various methods, such as transmission electron microscopy with x-ray dispersion spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy and zeta potential. In order to define the cellular uptake, the nanostructures were labelled with fluorescent dye Alexa647, and imaging and quantitative methods were applied: laser scanning confocal microscopy, flow cytometry and thermogravimetry. Our results indicate that cellular uptake of the studied nanospheres is size-dependent, and nanospheres of 90 nm in diameter showed the most efficient cell internalization. Thus, particle size is an important parameter that determines cellular uptake of nanoparticles and should be considered in designing drug delivery carriers.
Asunto(s)
Materiales Biocompatibles/síntesis química , Fibroblastos/química , Nanoporos/ultraestructura , Nanosferas/química , Nanosferas/ultraestructura , Dióxido de Silicio/química , Animales , Línea Celular , Difusión , Ensayo de Materiales , Ratones , Tamaño de la Partícula , Porosidad , Propiedades de SuperficieRESUMEN
In this paper, we present the technology of synthesis, characterization and release kinetics of anticancer drug molecules from sandwich-like mesoporous silica nanoflakes. Mesoporous silica nanoflakes are a very attractive material due to their versatility, low cytotoxicity, large surface area, high pore volume and unique feature of containing parallel pores openon both sides. Nanosilica flakes were prepared through the formation of a mesoporous silica layer on a graphene oxide surface. After graphene oxide removal, the silica nanostructures were filled by an anticancer drug-methotrexate. Release kinetics studies were performed in different temperatures, imitating the conditions in living organisms. Release data was analyzed using the zero-order model, first-order model, Higuchi model and Korsmeyer-Peppas model. The optical properties of samples, and the kinetics of drug release from the nanostructure, were examined by UV-vis spectrophotometer. Data obtained from long term studies showed that the system can serve as an anticancer drug carrier system, since a significant amount of methotrexate was loaded to the material and released. The mechanism of MTX release from mesoporous silica nanoflakes appeared to be a parallel processes of diffusion through water-filled mesopores and degradation of the mSiO2 matrix. Physical and chemical characterization was undertaken by transmission electron microscopy (TEM) and X-ray dispersion spectroscopy (EDX). The specific surface area of the samples was measured through the adsorption of N2 isotherm, interpreted with the Brunauer-Emmett-Teller model (BET). TGA and UV-vis analyses were conducted in order to estimate the amount of the released drug.