An Efficient Photothermal Therapy Agent By Using Ag Nanoparticles For Murine Melanoma Of The Skin And Iris Therapy

OBJECTIVES:Photothermal therapy (PTT) have been used in cancer therapy in recent years, however it is a virgin area in the field of ophthalmology. We created a new PTT agent --Silver-TiO2 core-shell nanoparticles (Ag@ TiO2 NPs) that possess stronger near-infrared (NIR) absorption and higher phototherma conversion efficiency. The purpose of this study was to demonstrate Ag@ TiO2 nanoparticles can be used as an effective PTT agent in vivo and vitro for melanoma Therapy.METHODS:Ag NPs were synthesized using a seed-mediated procedure. Ag@ TiO2 NPs were prepared via a simple sol-gel route. The thickness of the oxides shell can be precisely tuned from 1 to 15 nm through changing the reaction time and amount of oxides sol-gel precursor. For measuring the photothermal conversion performance of the Ag@ TiO2 core-shell NPs, 1mL aqueous dispersion of Ag@ TiO2 NPs with different concentrations were introduced in a quartz cuvette and irradiated with an 808 nm NIR laser at a power density of 2 W·cm-2.Cytotoxicity and therapeutic efficiency of Ag NP were tested in B16F10 cells and OCM-1 cells using MTT assay. Mice were for melanoma tumor model. The tumor body were injected Ag@ TiO2 NPs then exposed to an 808 nm laser at 2 W·cm-2, immediately. The photothermal effectiveness of Ag NP was evaluated by measuring the size of the tumor.RESULTS:We developed a facile method to synthesize Ag@ TiO2 core-shell NPs with a tunable shell thickness through the simple sol-gel route. Ag@ TiO2 exhibits a good biocompatiblity and stability for in vivo and vitro due to the existence of oxide shell layer. The localized surface plasmon resonance (LSPR) absorption band of Ag@ TiO2 When the light at 808 nm illuminated the Ag@ TiO2 NPs, the temperature of media surrounding Ag@ TiO2 NPs rapidly rose up, resulting in significant B16F10 cells (p<0.01) and OCM-1 cells (p<0.01) death in Ag NPs-treated (100μg·mL-1) in vitro. The tumor of mice disappeared after 16 days after treatment with both the NPs and laser irradiation in subcutaneous tumor model; The tumor size of Ag NPs+laser group were significantly less than other groups in three days after treatment in melanoma of iris model. In cytotoxicity of Ag@TiO2 NPs experiment demonstrated that the cells showed well tolerated to Ag@ TiO2 NPs, and cells have the viability in Ag NPs-treated (200 μg·mL-1); and the mice remained healthy over one-month period.CONCLUSION:Ag@ TiO2 NPs were demonstrated to be an efficient photothermal therapy agent for solid cancers by local delivery.