Novel functional mesoporous silica nanoparticles loaded with Vitamin E acetate as smart platforms for pH responsive delivery with high bioactivity.

Vitamin E (VE) exerts promising antioxidant activities against free radicals. However, its therapeutic efficacy and practical application are greatly restricted as a result of poor solubility, instability and low bioavailability. In this work, novel amino functionalized mesoporous silica nanoparticles (MSNs) were employed as the smart carriers to encapsulate Vitamin E acetate by the combination of soft-template method and recrystallization approach. Typically, two different surfactants were used as organic templates to fabricate different MSNs with various pore size distributions (∼4nm and ∼25nm). According to the characterization results such as Brunauer-Emmet-Teller (BET), fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), thermal gravity analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD), dynamic light scattering (DLS) and UV-vis diffuse reflectance spectroscopy, the drug delivery systems were successfully fabricated and the loading capacity (LC%) and entrapment efficiency (EE%) were also assessed. In addition, the results revealed that the VE loaded nanoparticles dispersed very well in PBS (pH = 7.4) and released VE in a pH-responsive manner. Importantly, the antioxidant effects of the VE loaded nanoparticles were also investigated by DPPH assays after exposure to air for 48h, showing that VE molecules encapsulated inside the mesoporous channels suffered from less degradation, compared to the pure VE. In vitro cell tests and hemolytic experiments revealed the outstanding biocompatibility and low cytotoxicity. In conclusion, the functionalized mesoporous silica combined with VE might act as potential antioxidant drug formations in clinical application.