Functionalized Mesoporous Silica Nanoparticles as a Novel Antioxidant Delivery System

Antioxidants have an important role in control and prevention of dangerous diseases like cancers, but instability and high solubility of the antioxidants are major challenges of pharmaceutical researchers. Thus, using a suitable carrier for an antioxidant can enhance the antioxidant stability and protect it from reacting with the other existing molecules in the blood circulation. Mesoporous silica nanoparticles (MSNs) have been widely used as a carrier for therapeutic applications because of their suitable biological properties. This study attempts to improve the surface properties and increase antioxidant loading by functionaliztion of MSNs with 3-aminopropyltriethoxysilane (AP-MSNs) via post- synthesis grafting method. Synthesized nanoparticles were characterized by Scanning electron microscopy (SEM), Zetasizer and Fourier transform infrared spectroscopy (FTIR). Gallic acid (GA) was loaded into AP-MSNs. To optimize GA loading capacity, two effective parameters: GA concentration and embedding time were investigated. So different concentrations of GA in EtOH (1-50 mg/mL) were prepared and sampling was done in 24 and 48 h. Results showed that the best GA loading capacity was obtained at a concentration of 40 mg/mL in 48 h. The maximum GA loading capacity and entrapment efficiency were obtained 46 and 20%, respectively, determined by spectrophotometry and high-performance liquid chromatography (HPLC) analysis.