Gold modified polydopamine coated mesoporous silica nano-structures for synergetic chemo-photothermal effect

Near infrared (NIR) responsive agents have attracted a great attention in nanomedicine due to their efficient photothermal effect (PTE) and eco-friendly nature. In our study, a novel kind of nanostructure were developed based on mesoporous silica nanoparticles (MSN) loaded doxorubicin(DOX) core and polydopamine-gold nanoparticles shell (PDA-AuNPs), the system was designed for combined chemo and photothermal therapy into one system. The designed nanostructure were thoroughly characterized to confirm their structure and to ensure their efficiency as cargo delivery system (DDS). The pH controlled release behavior of DOX from the designed nanostructures was investigated, approximately 60% of DOX was released over 48 h. Under NIR irradiation, the nanoparticles exhibited good photothermal stability and a high photothermal conversion efficiency of approximately 49%. Importantly, the MSN@DOX-PDA-AuNPs nanostructures showed a synergetic photo and chemotherapeutic effect, with the enhanced DOX release by 19% over 15 h and 15.42% over 250 min with 4 cycles of NIR laser irradiation. The combined chemo-photothermal in an acidic environment and under NIR irradiation was successfully proved.