Stepwise photothermal therapy and chemotherapy by composite scaffolds of gold nanoparticles, BP nanosheets and gelatin immobilized with doxorubicin-loaded thermosensitive liposomes

In recent years, the synergistic effect of photothermal therapy (PTT) and chemotherapy has been recognized as an effective strategy for cancer treatment. Controlling the PTT temperature and drug release profile is desirable for minimizing the unexpected damage to normal cells. In this study, a smart platform of stepwise PTT and chemotherapy has been developed by using composite porous scaffolds of biodegradable black phosphorus (BP) nanosheets, gold nanorods(AuNRs), doxorubicin (Dox)-encapsulated thermosensitive liposomes and biodegradable polymers. Under near-infrared (NIR) laser irradiation, the composite scaffolds could attain high and low local temperatures before and after BP degradation, respectively. Dox release from the composite scaffolds could be controlled by the temperature change. In vitro cell culture and in vivo animal experiments indicated that a strong synergistic effect of PTT and chemotherapy could be achieved at an early stage of treatment before BP degradation, and a mild hyperthermia effect was shown for chemotherapy in the late stage after BP degradation. Moreover, the composite scaffolds after the complete release of Dox could support the proliferation of mesenchymal stem cells. The composite scaffolds showed a synergistic effect of stepwise PTT and chemotherapy for breast cancer elimination and promoted stem cell activities after killing cancer cells.

Automated summary

This study developed a smart platform for stepwise photothermal therapy (PTT) and chemotherapy, which effectively achieved synergistic effects of PTT and chemotherapy while minimizing damage to normal cells. The temperature and drug release from the composite scaffolds could be controlled, allowing for high local temperatures during PTT and controlled drug release during chemotherapy. In vitro and in vivo experiments demonstrated the strong synergistic effect of the combined therapy, with a mild hyperthermia effect after degradation of black phosphorus (BP). Additionally, the composite scaffolds supported the proliferation of mesenchymal stem cells after complete drug release.