Multifunctional CuS nanocrystals for inhibiting both osteosarcoma proliferation and bacterial infection by photothermal therapy

Photothermal therapy (PTT) has attracted great attention in cancer therapy because of high efficiency and low side effect. The semiconductors have been proved to be ideal photothermal agents in the past years. Herein, we synthesized a novel hexahedron structure of polyvinyl pyrrolidone (PVP) coating CuS nanocrystals (NCs) by a facile hydrothermal method. The synthesized CuS NCs (150 nm for average length of edge and 125 nm for length of width) have good biocompatibility due to their PVP coating and strong absorption in the near infrared region. Moreover, the CuS NCs exhibit high photothermal conversion efficiency as well as good antibacterial effect. Notably, the proliferation of osteosarcoma cancer cells can be efficiently inhibited both in vitro and in vivo by the fatal heat with very low concentration of CuS NCs under the near infrared ray at a power density of 0.5 W/cm². Therefore, the CuS-PVP NCs have great potential to work as an ideal photothermal and antibacterial agent in clinical applications.