A single near-infrared light-triggered nanoplatform based on upconversion nanoparticles for synergistic...

Gynecological tumors pose a serious risk to female health, and traditional therapies have many limitations. Here, we developed a near-infrared light-triggered nanoplatform (UCNPs@SiO₂-MB@PDA) for synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) of deep tumors. The nanoplatform takes the UCNPs as the core, wraps the silica shell loaded with the photosensitizer MB via the inverse microemulsion method, and finally modifies the surface of the PDA. Under 980 nm excitation, the red light emitted by the UCNPs can effectively activate MB to produce singlet oxygen through luminescence resonance energy transfer, achieving PDT. At the same time, the PDA shell can efficiently absorb the multiband emitted light of the UCNPs and convert it into thermal energy, achieving PTT with a photothermal conversion efficiency of 35.6%. In vitro cell experiments have shown that the material has good biocompatibility and can be effectively internalized by tumor cells. Under near-infrared light irradiation, its killing effect on HeLa cells was considerably better than that of monotherapy, and the cell survival rate decreased to 18.9% when the cells were exposed to a concentration of 200 μg/mL. The results of the live/dead cell staining further confirmed the excellent synergistic antitumor performance of these materials. This work offers a promising strategy for the precise and effective treatment of deep tumors.