Redox responsive Pd(ii) templated rotaxane nanovalve capped mesoporous silica nanoparticles: a folic acid mediated biocompatible cancer-targeted drug delivery system

Abstract

In this study, we report a redox responsive drug delivering nanocarrier design based on mesoporous silica nanoparticles. Gatekeeping of the mesopore is achieved using Pd(II) templated, mechanically interlocked rotaxane nanovalves with a folic acid terminal group, anchored by a disulfide bridge as a snap-top on the surface. The active metal templated rotaxane approach helps in quick and irreversible gate formation for effective utilization of the drug. The folic acid head group bestows targeting capability, specifically to cancer cells. Once nanoparticles enter the cancer cell, controlled release of the cargo is triggered by cleavage of the disulfide bond using an endogenous glutathione stimulus. In addition to having efficient drug loading and controlled release mechanisms, this smart biocompatible carrier system showed obvious uptake and consequent release of the drug in HeLa cells, demonstrating its use as a potential theranostic material.