Preparation and Characterization of SiO<SUB>2</SUB>–Au Nanoshells: <I>In</I> <I>Vivo</I> Study of Its Photo-Heat Conversion

In the event of cancer treatment, photothermal therapy has met successful cancerous cells damage with highly reduced toxicity to normal cells. The prepared GNSs samples have been characterized using transmission electron microscope (TEM), dynamic light scattering, zeta potential and UV-VIS absorption spectroscopy. In-vivo photo-heat conversion of GNSs accumulated in Ehrlich tumor cells inoculated in female balb mice was monitored by measuring tumor tissue temperature as a function of NIR laser exposure time. Resultant heating and therapeutic efficacy were assessed by monitoring tumor growth/regression and tumor cells necrotic percentage. Histopathological examinations for treated and control tumors using light microscope and transmission electron microscopes (TEM) were performed to evaluate the treatment effects. Passively targeted pegylated gold nanoshells were found to have localized photo-heat conversion sufficient to selectively destruct tumor cells. This has been emphasized by the significant decrease in Ehrlich tumor volume for treated groups that administrated either intratumorly (IT) or intravenously (IV) with GNSs. Light microscope examinations revealed high necrotic percentages for both administration routes. TEM images showed degenerated cell membrane and nuclear envelop as well as the appearance of nucleus debris and other cell organelles. This non-invasive protocol showed great promise as a technique for selective cancer photo-thermal therapy.