Methylene blue-loaded gold nanobipyramids @SiO2 enhanced singlet oxygen generation for phototherapy of cancer cells

Plasmonic nanoparticles hold great potential in photodynamic therapy (PDT). Herein, a nanoplatform of methylene blue (MB) loaded gold nanobipyramids@SiO2 (GBPs@SiO2-MB) was designed to optimize the generation rate of singlet oxygen (O-1(2)), which was based on the plasmonic effect. The surface plasmon resonance (SPR) of GBPs was finely overlapped with the excitation absorption of MB, a wildly applied organic PDT drug prone to enzymatic degradation. This mesoporous silica coating nanoplatform protects MB molecules against degradation, and this overlap greatly enhances the O-1(2) yield of MB by the SPR electron from the GBPs. The GBPs@SiO2-MB nanoparticles exhibit a synergistic effect of PDT and photothermal therapies (PTT) of cancer cells under laser irradiation. This study provides a alternative strategy to improve the classic MB treatment for phototherapy application. (C) 2017 Optical Society of America