Synthesis and characterization of mesoporous silica-g-poly(hydroxyethylmethacrylate) nanohybrid particles as a drug delivery system

Abstract

Hybrid nanoparticles (MSiO2/TMSPMA-g-PHEMA) based on poly(hydroxyethylmethacrylate) (PHEMA) grafted onto mesoporous silica particles (MSiO2) were prepared using “grafting from” approach by free radical polymerization. According to thermogravimetric analysis (TGA), the amount of grafted PHEMA increased as a function of the quantity of monomer feed. The hybrid nanoparticles were uniformly shaped as ellipsoids with a mean size diameter of 74 nm. Textural characterization and transmission electron microscopy (TEM) demonstrated that the morphology and structural framework of the materials were maintained. The grafted PHEMA favored that MSiO2/TMSPMA-g-PHEMA system could be well dispersed in an aqueous solution, showing pH dependence. The hybrid nanoparticles were capable to load 5FU with a maximum efficiency of 36.6% ± 5.4%. The drug release rate of (MSiO2/TMSPMA-g-PHEMA)/5FU was pH dependent and reached up to 86 ± 2.58% after 4 h at pH 7.4, much higher than at pH 2, which was only 46 ± 3.20% in 3.5 h. In vitro cytotoxicity test showed that hybrid MSiO2 were cytotoxic against U87 glioblastoma cells, indicating that the dosage-dependent effect of the hybrid delivery system was more effective than free 5FU. These results suggested that the MSiO2/TMSPMA-g-PHEMA is a potential system to be used as drug carrier for cancer therapy.