Dual Stimuli-Responsive Multifunctional Silicon Nanocarriers for Specifically Targeting Mitochondria in Human Cancer Cells

Specific targeting, selective stimuli-responsiveness, and controlled release of anticancer agents are requested for high therapeutic efficiency with a minimal adverse effect. Herein, we report the sophisticated synthesis and functionalization of fluorescent mesoporous silicon (FMPSi) nanoparticles decorated with graphene oxide (GO) nanosheets. GO-wrapped FMPSi (FMPSi@GO) was loaded with a cisplatin (Cis) anticancer agent, and Cis-loaded FMPSi@GO (FMPSi-Cis@GO) exhibited the dual stimuli (pH and NIR)-responsiveness of controlled drug release, i.e., the drug release rate was distinctly enhanced at acidic pH 5.5 than at neutral pH 7.0 and further enhanced under NIR irradiation at acidic pH condition. Notably, dequalinium-conjugated FMPSi-Cis@GO (FMPSi-Cis@GO@DQA) demonstrated an excellent specificity for mitochondrial targeting in cancer cells without noticeable toxicity to normal human cells. Our novel silicon nanocarriers demonstrated not only stimuli (pH and NIR)-responsive controlled drug release, but also selective accumulation in the mitochondria of cancer cells and destroying them.