Photolabile plasmonic vesicles assembled from amphiphilic gold nanoparticles for remote-controlled traceable drug delivery.

We have developed a new type of photo-responsive plasmonic vesicles that allow for active delivery of anticancer payloads to specific cancer cells and personalized drug release regulated by external photo-irradiation. Our results show that amphiphilic gold nanoparticles carrying hydrophilic poly(ethylene glycol) (PEG) and photo-responsive hydrophobic poly(2-nitrobenzyl acrylate) (PNBA) can assemble into plasmonic vesicles with gold nanoparticles embedded in the hydrophobic shell of PNBA, which can be converted into hydrophilic poly(acrylic acid) upon photo exposure. Benefiting from the interparticle plasmonic coupling of gold nanoparticles in close proximity, the plasmonic vesicles assembled from amphiphilic gold nanoparticles exhibit distinctively different optical properties from single nanoparticle units, which offer the opportunity to track the photo-triggered disassembly of the vesicles and the associated cargo release by plasmonic imaging. We have shown the dense layer of PEG grafts on the vesicles not only endow plasmonic vesicles with excellent colloidal stability, but also serve as flexible spacers for bioconjugation of targeting ligands to facilitate the specific recognition of cancer cells. The targeted delivery of model anticancer drug doxorubicin, investigated by dual-modality plasmonic and fluorescence imaging and toxicity studies, clearly demonstrated the potential of photolabile plasmonic vesicles as multi-functional drug carriers.