In vitro evaluation of folic acid-conjugated redox-responsive mesoporous silica nanoparticles for the delivery of cisplatin.

The use of cisplatin(IV) prodrugs for the delivery of cisplatin have gained significant attention, because of their low toxicity and reactivity. Recent studies have shown that targeted cisplatin(IV)-prodrug nanoparticle-based delivery systems can improve the internalization of the cisplatin(IV) prodrug. We hypothesized that folic acid-conjugated mesoporous silica nanoparticles (MSNs) containing cisplatin(IV) prodrug could target cancer cells that overexpress the folate receptor and deliver the active cisplatin drug upon intracellular reduction. To prove this hypothesis, internalization and localization studies in HeLa cancer cells were performed using flow cytometry and confocal microscopy. The ability of MSNs to escape from the endolysosomal compartments, the formation of DNA adducts, and the cytotoxic effects of the MSNs were also evaluated. Our results confirmed that this MSN-based delivery platform was capable of delivering cisplatin into the cytosol of HeLa cells, inducing DNA adducts and subsequent cell death.