Reduced graphene oxide gated mesoporous silica nanoparticles as a versatile chemo-photothermal therapy system through pH controllable release.

Synergistic therapy has become a potential treatment in the battle against disease. In this work, we developed a novel versatile folate targeted system for cancer cells with the combination of chemotherapy and phototherapy by using mesoporous silica nanoparticles (MSNs) as a drug loading carrier, in which reduced graphene oxide (rGO) gated the MSNs by pH responsive detachment. That is, rGO herein acts not only for gating control of the drug release but also for near-infrared photothermal therapy. With this drug loading system, high photothermal conversion efficiency and excellent doxorubicin (DOX) loading capacity have been achieved, making the DOX loaded MSN@rGO-FA (DOX@MSN@rGO-FA) nanocomposites able to kill 68% of HEp-2 cells in synergistic therapy, as compared with 54% in photothermal therapy and 33% in chemotherapy, respectively, illustrating that a synergistic therapy strategy using this newly developed versatile drug loading system is much more efficient as evaluated in vitro.