In situ fabrication of mesoporous silica-coated silver-gold hollow nanoshell for remotely controllable chemo-photothermal therapy via phase-change molecule as gatekeepers

This study reports a new strategy for in situ fabrication of plasmonic hollow silver-gold nanoshell (with resonance tuned to NIR region) encased in the hollow mesoporous silica as an efficient platform to efficiently and precisely regulate the release of 5-fluorouracil (anticancer drug) for prostate cancer therapy and photothermal therapy. The mesopores were capped with thermosensitive phase-change material lauric acid, which allowed for remote, precise, and spatiotemporal control of drug release via external heating or photothermal heating of plasmonic silver-gold nanoshell via NIR laser irradiation. The system was nanometric, monodispersed, and showed negative surface charge. The nanocarrier showed better pH stability and thermodynamic stability compared to dense silica-coated gold nanoshells. The drug release could be triggered remotely by applying low powered continuous wave NIR laser (λ = 808 nm). The nanocarrier showed improved internalization by cancer cells, which was further enhanced by laser irradiation. High powered laser directly killed the cancer cells via photothermal effect in the region irradiated. Thus, this system fabricated by novel synthetic strategy provided efficient chemo- and phototherapy.