A Hollow‐Structured CuS@Cu2S@Au Nanohybrid: Synergistically Enhanced Photothermal Efficiency and Photoswitchable Targeting Effect for Cancer Theranostics

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@Cu₂S@Au nanoshell/satellite nanoparticles are designed and synthesized for enhanced photothermal therapy and photoswitchable targeting theranostics. The remarkably improved photothermal conversion efficiency of CuS@Cu₂S@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 Cu₂S 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@Cu₂S@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.     

Glutathione Depletion in a Benign Manner by MoS2‐Based Nanoflowers for Enhanced Hypoxia‐Irrelevant Free‐Radical‐Based Cancer Therapy

Tumor hypoxia significantly diminishes the efficacy of reactive oxygen species (ROS)‐based therapy, mainly because the generation of ROS is highly oxygen dependent. Recently reported hypoxia‐irrelevant radical initiators (AIBIs) exhibit promising potential for cancer therapy under different oxygen tensions. However, overexpressed glutathione (GSH) in cancer cells would potently scavenge the free radicals produced from AIBI before their arrival to the specific site and dramatically limit the therapeutic efficacy. A synergistic antitumor platform (MoS₂@AIBI‐PCM nanoflowers) is constructed by incorporating polyethylene‐glycol‐functionalized molybdenum disulfide (PEG‐MoS₂) nanoflowers with azo initiator and phase‐change material (PCM). Under near‐infrared laser (NIR) irradiation, the photothermal feature of PEG‐MoS₂ induces the decomposition of AIBI to produce free radicals. Furthermore, PEG‐MoS₂ can facilitate GSH oxidation without releasing toxic metal ions, greatly promoting tumor apoptosis and avoiding the introduction of toxic metal ions. This is the first example of the use of intelligent MoS₂‐based nanoflowers as a benign GSH scavenger for enhanced cancer treatment.