Chemical-NIR dual-powered CuS/Pt nanomotors for tumor hypoxia modulation,deep tumor penetration and augmented synergistic phototherapy

The complex tumor microenvironment(TME)with the characteristics of severe hypoxia,enriched hydro-gen peroxide(H_(2)O_(2))and dense nature significantly restricted the therapeutic efficacy of nanomedicine in cancer treatment.Synthetic micro/nanomotors have shown multiple versatility in modulating the abnor-mal TME and overcoming the limited penetration in solid tumor.Herein,we constructed a chemical-NIR dual-propelled nanomotor based on CuS/Pt Janus nanoparticles with IR820 encapsulation for hypoxia alle-viation,deep tumor penetration and augmented synergistic photodynamic(PDT)and photothermal ther-apy(PTT).The deposited Pt effectively catalyzed tumor endogenous H_(2)O_(2) into oxygen,which extremely relieved the tumor hypoxia state and allowed the chemical propulsion of nanomotors.Under NIR irra-diation,the Janus nanomotors exhibited more obvious movement via efficient photothermal conversion.Such autonomous motion significantly improved the tumoral accumulation of nanomotors and facilitated much deeper penetration inside tumor in vivo.In addition,enriched oxygen also promoted the genera-tion of reactive oxygen species(ROS)for augment of PDT,which achieved satisfied antitumor effect in combination with the PTT treatment.Therefore,this strategy based on CuS/Pt Janus nanomotors would provide an innovative dimension for considerable applications in effective cancer management.

High photocatalytic activity of Cu2O/TiO2/Pt composite films prepared by magnetron sputtering

Cu2O/TiOa/Pt three-layer films were deposited on glass substrates using magnetron sputtering method. The surface morphology and the optical properties of the composite film were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, ultraviolet- visible spectroscopy （UV-Vis） and photoluminescence spectroscopy （PL）. The photocatalytic activity of the samples was evaluated by the photocatalytic degradation of methyl orange （MO） aqueous solution under visible light irradiation. The results indicate that the Cu2O/TiO2/Pt composite films are made up of three layers which are Pt layer, anatase-TiO2 layer and Cu2O layer from bottom to top. The surface of the films is even and composed of regular-shaped spherical particles. The photocatalytic activity of the Cu2O/TiO2/Pt three-layer film is much higher than that of the Cu2O/TiO2 double-layer film. Such enhancement is ascribed to the presence of Pt layer, which further inhibits the photogenerated electron-hole recombination, prolongs the lifetime of the photogenerated carriers, increases the quantum efficiency and hence improves the photocatalytic activity of the film effectively.