Doxorubicin-loaded CuS/Tween-20 nanocomposites for light-triggered tumor photothermal therapy and chemotherapy.

In clinical tumor therapy, traditional treatments such as surgery, radiotherapy and chemotherapy all have their own limitations. With the development of nanotechnology, new therapeutic methods based on nanomaterials such as photothermal therapy (PTT) have also emerged. PTT takes advantage of the poor thermal tolerance of tumor cells and uses the heat generated by photothermal reagents to kill tumor cells. A transition metal sulfide represented as CuS is an ideal photothermal reagent because of its easy preparation, high extinction coefficient and photothermal conversion efficiency. Surface modification of nanoparticles (NPs) is also necessary, which not only can reduce toxicity and improve colloidal stability, but also can provide the possibility of further chemotherapeutic drug loading. In this work, we report the fabrication of Tween-20 (Tw20)-modified and doxorubicin (Dox)-loaded CuS NPs (CuS/Dox@Tw20 NPs), which significantly improves the performance in tumor therapy. Apart from the enhancement of colloidal stability and biocompatibility, the drug loading rate of Dox in Tw20 reaches 11.3%. Because of the loading of Dox, CuS/Dox@Tw20 NPs exhibit chemotherapeutic behaviors and the tumor inhibition rate is 76.2%. Further combined with a near-infrared laser, the high temperature directly leads to the apoptosis of a large number of tumor cells, while the release of chemotherapeutic drugs under heat can not only continue to kill residual tumor cells, but also inhibit tumor recurrence. Therefore, with the combination of PTT and chemotherapy, the tumor was completely eliminated. Both hematological analysis and histopathological analysis proved that our experiments are safe.