Multi-functional FITC-silica@gold nanoparticles conjugated with guar gum succinate, folic acid and doxorubicin for CT/fluorescence dual imaging and combined chemo/PTT of cancer

Abstract

A novel type of multi-functional fluorescein isothiocyanate (FITC)-silica (SiO₂)@gold (Au) core-shell nanoparticles covered with folic acid (FA)-conjugated guar gum succinate (GGS) and doxorubicin (DOX) (FITC-SiO₂@Au-DOX-GGS-FA NPs) was prepared for imaging and therapy of cancer. The physicochemical properties of these NPs were analyzed with ¹H NMR, TEM and DLS. The FITC-SiO₂@Au-DOX-GGS-FA NPs exhibited the fluorescence and X-ray attenuation properties due to the presence of FITC-SiO₂@Au hybrid nanostructure. Due to acid-cleavable hydrazone bond between the DOX and NPs, the quantity of DOX delivered from the FITC-SiO₂@Au-DOX-GGS-FA NPs was increased at pH 5.6 than that at pH 7.4. Besides, the multi-functional NPs presented the improved cellular uptake by HeLa cells via FA-receptor-mediated endocytosis due to the existence of FA. The developed NPs also presented the improved cytotoxicity towards the HeLa cells due to its tumor-targetability and DOX/photothermal effect. These results suggested that the FITC-SiO₂@Au-DOX-GGS-FA NPs could be ideal for computed tomography (CT)/fluorescence dual imaging and combined chemo/photothermal therapy (PTT) of cancer.

Keywords: Cancer therapy; Combined therapy; Drug delivery; Dual imaging; Nanoparticles.