A Macrophage Membrane-Coated Cu–WO_3–<i>x</i>-Hydro820 Nanoreactor for Treatment and Photoacoustic/Fluorescence Dual-Mode Imaging of Inflamed Liver Tissue

A disease-targeting nanoplatform that integrates imaging with therapeutic activity would facilitate early diagnosis, treatment, and therapeutic monitoring. To this end, a macrophage membrane-coated Cu–WO3–x-Hydro820 (CWHM) nanoreactor was prepared. This reactor was shown to target inflammatory tissues. The reactive oxygen species (ROS) such as H2O2 and ·OH in inflammatory tissues can react with Hydro820 in the reactor to form the NIR fluorophore IR820. This process allowed photoacoustic/fluorescence dual-mode imaging of H2O2 and ·OH, and it is expected to permit visual diagnosis of inflammatory diseases. The Cu–WO3–x nanoparticles within the nanoreactor shown catalase and superoxide enzyme mimetic activity, allowing the nanoreactor to catalyze the decomposition of H2O2 and ·O2– in inflammatory cells of hepatic tissues in a mouse model of liver injury, thus alleviating the oxidative stress of damaged liver tissue. This nanoreactor illustrates a new strategy for the diagnosis and treatment of hepatitis and inflammatory liver injury

Ceria-Induced Strategy To Tailor Pt Atomic Clusters on Cobalt–Nickel Oxide and the Synergetic Effect for Superior Hydrogen Generation

A new and reusable hybrid catalyst of Pt/CeO₂–Co₇Ni₂O_<i>x</i> is fabricated readily, in which a high dispersion of Pt atomic cluster is successfully achieved by the introduction of CeO₂. The oxidation states of each elemental metal in varied compositions are studied systematically to design the catalyst. The optimal Pt/CeO₂–Co₇Ni₂O_<i>x</i> catalyst exhibits an extremely high specific H₂ evolution rate of 7834.8 mL_H2 min^–1 g_cat^–1 and turnover frequency of 679.0 mol_H2 min^–1 mol_Pt^–1 for the hydrolysis of alkalized NaBH₄ solution. It is one of the most efficient catalysts so far, and the reason is ascribed to the lower activation energy (47.4 kJ mol^–1) as we confirmed. The lower energy barrier and high performances mainly results from the ultrasmall Pt atomic clusters, which have more active sites to adsorb and break the B–H bonds in BH₄^– ions for the generation of negative charged H^– via electron transfer, and then the H^– can immediately combine with the positive charged H⁺ (originated from the weakened H–O–H bond on the Ce–Co–Ni oxide) to produce H₂ fast