Quercetin Loaded Silica and Gold - Coated Silica Nanoparticles: Characterization, Evaluation and Comparison of Their in vitro Characteristics

Herein, silica nanoparticles (NPs) and gold-silica NPs were loaded with the anti-cancer agent quercetin (QC) to produce silica NPs-QC and gold coated silica NPs-QC, respectively. The nanosystems were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared (FTIR). Drug encapsulation efficiency (EE), loading capacity (LC) and release rate were measured using UV spectrophotometer. The drug was encapsulated in silica NPs in a high percentage (71%) and reduced by about 16% after gold coating. The mean particle size increased after coating and QC loading with a polydispersity index (PDI) between (∼ 0.2 - 0.6) and negative zeta potential (-13 to - 15 mV). The intensity of FTIR peaks of silica NPs has been significantly decreased upon gold coating indicating a successful attachment of the gold thin layer. The drug release was slightly faster from coated compared to uncoated NPs but both slower than free QC. The percentages of their cell toxicity were almost the same but lower than free QC and generally were higher against HeLa cells compared to fibroblast cells. Both nanosystems could be considered as promising nanocarriers with reasonable EE, slower release rate and lower toxicity compared to the free drug.