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Lattice oxygen in metal oxides plays an important role in the reaction of diesel oxidation catalysts, but the atomic-level understanding of structural evolution during the catalytic process remains elusive. Here, we develop a Mn2O3/SmMn2O5 catalyst using a non-stoichiometric exsolution method to explore the roles of lattice oxygen in NO oxidation. The enhanced covalency of Mn–O bond and increased electron density at Mn3+ sites, induced by the interface between exsolved Mn2O3 and mullite, lead to the formation of highly active lattice oxygen adjacent to Mn3+ sites. Near-ambient pressure X-ray photoelectron and absorption spectroscopies show that the activated lattice oxygen enables reversible changes in Mn valence states and Mn-O bond covalency during redox cycles, reducing energy barriers for NO oxidation and promoting NO2 desorption via the cooperative Mars-van Krevelen mechanism. Therefore, the Mn2O3/SmMn2O5 exhibits higher NO oxidation activity and better resistance to hydrothermal aging compared to a commercial Pt/Al2O3 catalyst. This work reports on an exsolved Mn2O3/SmMn2O5 diesel oxidation catalyst competitive with current commercial materials in reactivity and hydrothermal aging resistance and further clarifies the catalytic mechanism for lattice oxygen as the reactive center [ABSTRACT FROM AUTHOR]

This study aimed to obtain paeonol with high purity by using the combination of steam distillation and antisolvent recrystallization (ASR) and to reduce the energy consumption and CO2 emission in the preparation process. First, different experimental parameters were optimized by response surface methodology (RSM). Under the optimal conditions, the purity and yield of the as‐obtained paeonol were about 98% and 56.97%, respectively. The physicochemical properties of purified paeonol were tested, showing consistency with those of standard paeonol. The energy consumption and CO2 emission of the preparation process of ASR and single‐solvent recrystallization were also investigated. Results showed that the energy consumption and CO2 emission of ASR were about 4.41 J/mg and 0.006 kg/mg, respectively, which were 6.89 J/mg and 0.0095 kg/mg lower than those of ethanol recrystallization, respectively, and 50.22 J/mg and 0.0144 kg/mg lower than methanol those of recrystallization, respectively. The above results showed that ASR could obtain paeonol with high purity in a high‐efficiency, low‐energy, and environmentally protective manner. [ABSTRACT FROM AUTHOR]

Aim: To formulate and assess the anticancer effect of the poly(lactic-co-glycolic acid) (PLGA) copolymer with the thioether groups (diethyl sulfide [Des]) and disulfide bond (cystamine containing disulfide [Cys]), which encapsulated the anticancer drug paclitaxel (PTX) and triggered PTX release in cancer cell H2O2-rich or glutathione-rich surroundings. Methods: PLGA-b-P (Des@Cys) and PLGA-b-P nanoparticles loaded with PTX were prepared and characterized in vitro. The delivery ability of the PLGA-b-P nanoparticles and PLGA-b-P-PTX nanoparticles was assessed on a CT26 (mouse colon cancer cell line) and mouse lung cancer LLC model. Results: The nanoparticles were successfully prepared. Compared with free PTX, the formulated PLGA-b-P nanoparticles loaded with PTX exhibited greater accumulation at the tumor site in the mouse model. Conclusion: PLGA-b-P nanoparticles promote drug accumulation at tumor sites, providing an effective strategy for an intelligent, responsive drug-delivery system. Cancer is one of the diseases with the highest mortality rate in the world. Chemotherapy is the most frequently used method of cancer treatment. However, traditional chemotherapeutic drugs have the disadvantages of lack of specificity, high toxicity to the human body, lack of tumor targeting, inability to exist stably in the body, ease of clearance by the body and drug resistance to tumors, so clinical application is limited. Paclitaxel is widely used in the treatment of various cancers, and its use is limited due to the above disadvantages. The purpose of this study was to construct a nanodelivery system with dual responses to the tumor microenvironment, enabling the efficient accumulation of paclitaxel in solid tumors through the enhanced permeability and retention effect, enhancing the therapeutic effect of cancer. This study also investigated the intravenous safety of this dual-responsive nanodelivery system. It evaluated the toxic effects of drug-loaded nanoparticles on cancer cells and validated the controlled release of nanoparticles at tumor sites by in vivo imaging in mice. The authors concluded that tumor microenvironment dual-responsive nanoparticles are a novel and promising nanodelivery system as an intelligently responsive anticancer agent with great promise in future clinical trials. This study prepared polymer nanocarriers (PLGA-b-p-NPs) with double response to the tumor microenvironment and loaded with traditional antitumor drug paclitaxel, so that drugs can accurately reach tumor cells and be rapidly released in cells. [ABSTRACT FROM AUTHOR]