The inherent radioresistance and inaccuracy of localization of tumors weaken the clinical implementation effectiveness of radiotherapy. To overcome these limitations, hyaluronic acid-functionalized bismuth oxide nanoparticles (HA-Bi 2 O 3 NPs) were synthesized by one-pot hydrothermal method for target-specific computed tomography (CT) imaging and radiosensitization of tumor. After functionalization with hyaluronic acid, the Bi 2 O 3 NPs possessed favorable solubility in water and excellent biocompatibility and were uptaken specifically by cancer cells overexpressing CD44 receptors. The as-prepared HA-Bi 2 O 3 NPs exhibited high X-ray attenuation efficiency and ideal radiosensitivity via synergizing X-rays to induce cell apoptosis and arrest the cell cycle in a dose-dependent manner in vitro. Remarkably, these properties offered excellent performance in active-targeting CT imaging and enhancement of radiosensitivity for inhibition of tumor growth. These findings demonstrated that HA-Bi 2 O 3 NPs as theranostic agents exhibit great promise for CT imaging-guided radiotherapy in diagnosis and treatment of tumors.

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IntroductionAlthough oral administration of Bifidobacterium is a promising approach for diseases, lack of resistance to harsh conditions and real-time tracking in gastrointestinal system in vivo are still major challenges in basic research and clinical applications.Materials and methodsIn this study, we fabricated a chitosan-coated alginate microcapsule loaded with in situ synthesized barium sulfate (CA/BaSO4 microcapsule) for oral Bifidobacterium delivery and real-time X-ray computed tomography (CT) imaging. CA/BaSO4 microcapsules containing the Bifidobacterium were prepared in situ by one-step electrostatic spraying method, and then coated with chitosan.ResultsThe results indicated that CA/BaSO4 microcapsules with an average diameter of approximately 200 μm possessed favorable mechanical stability and X-ray attenuation capacity. Encapsulation of Bifidobacteria in the CA/BaSO4 microcapsules exhibited superior resistance to cryopreservation and gastric acid environment in vitro. After oral administration in mice, these CA/BaSO4 microcapsules could be real-time visualized by CT imaging and readily reached the intestine to release Bifidobacteria.ConclusionThe radiopaque CA/BaSO4 microcapsules provide a novel platform for efficient protection, non-invasive real-time monitoring and intestinal-targeted Bifidobacterium delivery.

This paper reports a novel and facile activation process for electroless copper plating on Acrylonitrile Butadiene Styrene (ABS) plastic substrate using gold nanoparticles as catalyst. Gold nanoparticles were prepared by chemical reduction method and characterized by UVvisible adsorption spectrum and transmission electron microscope (TEM). The gold nanoparticles were sphere-like with a size of less than 50 nm. Gold nanoparticles were adsorbed on ABS surface and acted as nucleation centers in activating process of the electroless copper plating. The uniform and dense film was obtained at the optimal technological parameters which were achieved by the orthogonal experiment. The scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) were used to detect the morphology, structure and elemental composition of the coating, respectively. The results indicated that copper coating contained only Cu (0) without any other elements.