Photocatalytic and photothermal bismuthene nanosheets as drug carrier capable of generating CO to improve drug sensitivity and reduce inflammation for enhanced cancer therapy

Bismuthene nanosheet is a nontoxic and low-cost two-dimensional material, and has been reported with very limited biomedical applications. In this report, for the first time, we reported the utilization of bismuthene nanosheet for combined photothermal, photocatalytic and chemotherapy for cancer treatment. Partially oxidized bismuthene nanosheet was modified with polyethylene glycol (POBNS-PEG) and used as a drug delivery vehicle for the first time (antitumor drug doxorubicin (DOX) was used as a model drug, POBNS-PEG/DOX). POBNS-PEG itself shows a photothermal treatment ability under the near infrared light and this treatment can additionally promote better cellular uptake of POBNS-PEG and DOX. More importantly, POBNS-PEG was found to be able to reduce CO2 in cancer cells to CO through photocatalytic pathways under red light irradiation for the first time. The generated CO could obviously reduce the inflammation caused by photothermal treatment and drug resistance of tumor cells caused by chemotherapy. These three combined functions bring the three-in-one multifunctional bismuthene nanosheets not only have a significant antitumor effect but also reduce the side effects, making it with high clinical potentials.