Drug molecules bridge with small gatekeeper to co-block mesoporous silica nanoparticles for drug delivery

In this study, a filter-like blocking system based on MSN with small gatekeeper 5- mercapto-2 nitrobenzoic acid (MNBA) has developed. The MNBA grafted nanoparticle MSN-SS-MNBA shows excellent blocking performance with negligible leakage when loaded with doxorubicin (DOX), and the release profiles illustrate stimuli-responsive property when triggered by GSH. Viability experiments indicate that MSN-SS-MNBA has obvious inhibition for both Hela cells and HCT116 cells, while showing good biocompatibility for L929 cells, which suggests that the modified MNBA has a synergistic effect on cancer cells-killing. Since the small grafted molecule MNBA cannot block the channels of MSN via self-assembly, a filter-like blocking model that the loaded drug bridged with modified MNBA to fulfill the blocking process is proposed. The novel blocking strategy provides a new possible way for pore blocking, and the small nanovalve can be used as synergistic molecule for cancer therapy.