A Hollow-Structured CuS@Cu₂ S@Au Nanohybrid: Synergistically Enhanced Photothermal Efficiency and Photoswitchable...

It is of great importance in drug delivery to fabricate multifunctional nanocarriers with intelligent targeting properties, for cancer diagnosis and therapy. Herein, hollow-structured CuS@Cu₂ S@Au nanoshell/satellite nanoparticles are designed and synthesized for enhanced photothermal therapy and photoswitchable targeting theranostics. The remarkably improved photothermal conversion efficiency of CuS@Cu₂ S@Au under 808 nm near-infrared (NIR) laser irradiation can be explained by the reduced bandgap and more circuit paths for electron transitions for CuS and Cu₂ S modified with Au nanoparticles, as calculated by the Vienna ab initio simulation package, based on density functional theory. By modification of thermal-isomerization RGD targeting molecules and thermally sensitive copolymer on the surface of nanoparticles, the transition of the shielded/unshielded mode of RGD (Arg-Gly-Asp) targeting molecules and shrinking of the thermally sensitive polymer by NIR photoactivation can realize a photoswitchable targeting effect. After loading an anticancer drug doxorubicin in the cavity of CuS@Cu₂ S@Au, the antitumor therapy efficacy is greatly enhanced by combining chemo- and photothermal therapy. The reported nanohybrid can also act as a photoacoustic imaging agent and an NIR thermal imaging agent for real-time imaging, which provides a versatile platform for multifunctional theranostics and stimuli-responsive targeted cancer therapy.