Engineering Bismuth Oxychloride─A Black Phosphorus Heterojunction for Synergistic Radio/Radiodynamic/Photothermal Therapy

Developing a multifunctional nanoplatform with integration of three or more tumor therapeutic modalities has been proposed as a promising anticancer therapeutic strategy. In this work, a PAH-BiOCl@BP heterojunction as a multifunctional nanoplatform for radio/radiodynamic/photothermal synergistic cancer therapy is designed and conducted. The PAH-BiOCl@BP heterojunction with high Z element can absorb X-ray efficiently and deposit a significant dose of radiation into cells, potentially to be an excellent radiosensitizing material. Meanwhile, the successful construction of the type-I heterostructure effectively prevents electron and hole recombination, resulting in high reactive oxygen species production via the “photocatalyst process” under X-ray irradiation. More importantly, the unique sub-band structure and the strong exciton effect of BP further boost the efficiency of radiodynamic therapy (RDT). Furthermore, the PAH-BiOCl@BP heterojunction possesses the ability to ablate the cancer cells by heat due to the strong photothermal conversion capacity. Experiments both in vivo and in vitro confirm that greater therapeutic effect is achieved by synergistic radiotherapy, RDT, and photothermal therapy based on the as-prepared PAH-BiOCl@BP heterojunction. This work may offer an approach to exploring multifunctional nanoplatforms with integration of three or more tumor therapeutic modalities.