Bismuth and ICG loaded mesoporous bioactive glass for cancer synergistic therapy of photothermal and photodynamic therapy in vitro

The research trend of cancer treatment has shifted from monotherapy to combination therapy. In this study, mesoporous bioactive glass (MBG) was used as a drug carrier, that combined photothermal therapy (PTT) and photodynamic therapy (PDT). The condition for photothermal therapy to achieve effective treatment is local hyperthermia in a short time, to achieve that, this study chose bismuth nanoparticle, an element that has good biocompatibility and high photothermal conversion efficiency (PCE = ∼ 40%) under the irradiation of near-infrared (NIR) laser, as photothermal agent. A photosensitizer-indocyanine green, ICG, which has good biocompatibility and can be triggered with NIR to generate reactive oxygen species (ROS), was also loaded in MBG. The MBG loaded with a photothermal agent and photosensitizer was named MBG@Bi-ICG. MBG@Bi has an excellent PCE = 47.67%, which helps to reach enough temperature for therapeutic effect. In combination with ICG, MBG@Bi-ICG achieves great cytotoxicity against A549 cancer cells after the irradiation of 808 nm laser source (IC50 = 96.5 μg/mL), due to the synergistic effect of local hyperthermia generated by the photothermal agent-bismuth nanoparticle, and ROS generated by photosensitizer-ICG.