A redox and pH dual-triggered drug delivery platform based on chitosan grafted tubular mesoporous silica

Tubular mesoporous silica (T-mSiO(2)) was facilely synthesized through a co-template method by using cetyltrimethylammonium bromide and alpha-Fe2O3 as the dual templates, and then disulfide (-SS-) bonds and carboxyl groups (-COOH) were introduced to the resultant T-mSiO(2) via the reaction with 2-carboxyethyl 2-pyridyl disulphide. The obtained -SS- grafted T-mSiO(2) (SS-T-mSiO(2)) was then grafted with chitosan (CS) via the amidation reaction between the -COOH groups on SS-T-mSiO(2) and the -NH2 groups on CS. The CS grafted SS-T-mSiO(2) (CSSS-T-mSiO(2)) was fully characterized by various technologies such as transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Finally, the as-synthesized CS-SS-T-mSiO(2) was used as the carrier for redox and pH dual-triggered delivery of 5-fluorouracil (5-FU), an anti-cancer drug, and the results indicate that the developed CS-SS-T-mSiO(2) might be a potential responsive carrier for redox and pH dual-triggered drug delivery.