Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Opt Express ; 29(11): 16153-16163, 2021 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-34154183

RESUMEN

We experimentally demonstrate how to accurately retrieve the refractive index profile of photonic structures by standard diffraction experiments and use of the rigorous coupled-wave analysis in the multi-wave coupling regime, without the need for taking any auxiliary data. In particular, we show how the phases of the Fourier components of a periodic structure can be fully recovered by deliberately choosing a probe wavelength of the diffracting radiation much smaller than the lattice constant of the structure. In the course of our demonstration, we accurately determine the slight asymmetry of the structure of nanocomposite phase gratings by light and neutron diffraction measurements.

2.
Dalton Trans ; 41(31): 9286-96, 2012 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-22555652

RESUMEN

Combined chemo and photothermal therapy in in vitro testing has been achieved by means of multifunctional nanoparticles formed by plasmonic gold nanoclusters with a protecting shell of porous silica that contains an antitumor drug. We propose a therapeutic nanoplatform that associates the optical activity of small gold nanoparticles aggregates with the cytotoxic activity of 20(S)-camptothecin simultaneously released for the efficient destruction of cancer cells. For this purpose, a method was used for the controlled assembly of gold nanoparticles into stable clusters with a tailored absorption cross-section in the vis/NIR spectrum, which involves aggregation in alkaline medium of 15 nm diameter gold colloids protected with a thin silica layer. Clusters were further encapsulated in an ordered homogeneous mesoporous silica coating that provides biocompatibility and stability in physiological fluids. After internalization in 42-MG-BA human glioma cells, these protected gold nanoclusters were able to produce effective photothermolysis under femtosecond pulse laser irradiation of 790 nm. Cell death occurred by combination of a thermal mechanism and mechanical disruption of the membrane cell due to induced generation of micrometer-scale bubbles by vaporizing the water inside the channels of the mesoporous silica coating. Moreover, the incorporation of 20(S)-camptothecin within the pores of the external shell, which was released during the process, provoked significant cell death increase. This therapeutic model could be of interest for application in the treatment and suppression of non-solid tumors.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Camptotecina/administración & dosificación , Oro/administración & dosificación , Nanopartículas del Metal/administración & dosificación , Dióxido de Silicio/administración & dosificación , Antineoplásicos Fitogénicos/química , Camptotecina/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Terapia Combinada , Oro/química , Calor , Humanos , Terapia por Láser , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Microscopía Electrónica de Transmisión , Neoplasias/terapia , Dióxido de Silicio/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...