BIOMATERIALS
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2023
·
IF 14
Ziwen Qiu,Zhenming Lu,Jiaqi Huang,Yingtao Zhong,Ni Yan,Renjiang Kong,Hong Cheng
Tumor cells overexpress programmed cell death ligand 1 (PD-L1) to impede immune responses and escape immune elimination. Development of effective combination regimens to sensitize immunotherapy is promising but always challenging. Herein, a self-reinforced photodynamic immunostimulator (designated as PCS) is constructed for metastatic breast cancer treatment through simultaneous downregulation and blockade of PD-L1. Specifically, PCS is prepared by encapsulating signal transducer and activator of transcription 3 (STAT3) inhibitor (Stattic) into photosensitizer (protoporphyrin IX) modified PD-L1 blockade peptide (CVRARTR) through drug self-assembly. PCS can facilitate the targeted drug accumulation in PD-L1 overexpressed breast cancer cells to block PD-L1 and inhibit the phosphorylation of STAT3 to downregulate PD-L1. Moreover, PCS increases intracellular oxidative stress to show a robust anti-proliferation effect through photodynamic therapy (PDT), which also triggers an immunogenic cell death (ICD) to expose the immunostimulatory signals. Consequently, the efficient PD-L1 inhibition and robust PDT of PCS synergistically suppress the malignant growth of breast cancer, and concurrently activate the systemic anti-tumor immunity for metastatic inhibition with no obvious side effects. Such a photodynamic immunostimulator may provide an effective combination regimen for therapies activated immunotherapy against metastatic breast cancer.
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PubMed
高影响因子
Journal of Cleaner Production
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2023
·
IF 11.1
Zhenxiong Ye,Huidi Zhang,Xujie Chen,Lifeng Chen,Kunyapat Thummavichai,Xinpeng Wang,Toyohisa Fujita,Yuezhou Wei
Palladium is versatile in many industrial applications due to its distinct physicochemical properties . Due to the scarcity of natural resources and the growing market demand, palladium recovery from wastes such as spent catalysts is receiving increasing attention. Here, a silica-supported thiourea resin (SiPS-TU) was prepared and applied to separate Pd(II) from spent catalysts. The SiPS-TU was fabricated through in situ polymerization and post modification method using amorphous macroporous silica as the matrix. Experimental results suggested that the optimal acidity for the adsorption process was 0.1 M under selected range, and the uptake of SiPS-TU was affected by H + and Cl − . The adsorbent showed rapid sorption kinetics with an equilibrium attained in 30 min, while more than 3 h was required for the commercial D840 resin. Column tests showed that SiPS-TU had excellent dynamic separation property for Pd(II) in continuous process. Around 215 bed volumes (430 mL) of Pd(II) solution could be effective treated by the SiPS-TU bed before breakthrough at 4 mL/min, while D840 resin bed was less effective under equivalent conditions (20 mL). In view of its satisfactory adsorption performances, palladium was successfully separated from the catalyst leaching solution by SiPS-TU. XPS spectra and DFT calculations indicated that the adsorption mechanism of SiPS-TU for Pd(II) mainly involved anion exchange and coordination. In conclusion, this study provides a feasible material for palladium recovery from practical leachate.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Cong Wu,Qinglong Liu,Yu Zhan,Wei Tan,Xiaoqian Wei,Qing Tong,Haiqin Wan,Lin Dong
Indoor volatile organic compounds (VOCs), represented by toluene, can pose a serious threat to human health. In this work, a series of Pd/TiO 2 catalysts with different surface structures ( i.e. , dispersion/valence of Pd species, surface Ti 3+ /oxygen defect concentration and Pd-TiO 2 interactions, etc. ) was constructed by various methods. It was found that the Pd/TiO 2 catalyst prepared by one-step reduction of NaBH 4 method (Pd/TiO 2 -N) with metallic Pd particles possessed more surface Ti 3+ /oxygen defects and stronger Pd-TiO 2 interaction than Pd/TiO 2 catalysts prepared by ethylene glycol reduction loading method (Pd/TiO 2 -E) and incipient wetness impregnation method (Pd/TiO 2 -I). Further photochemical characterizations and reaction mechanism study revealed that the relatively higher concentration of Pd 0 species on Pd particles, stronger Pd-TiO 2 interaction, and more surface Ti 3+ /oxygen defects on Pd/TiO 2 -N could facilitate the generation of more reactive oxygen species (ROS) under light irradiation. The partial oxidation of toluene to benzyl alcohol/benzaldehyde/benzoic acid and the subsequent ring-opening process were found to be highly determined by the valence states of Pd particles and the concentration of surface Ti 3+ /oxygen defects. This work provides instructive insights into the construction of highly efficient Pd/TiO 2 catalysts for the removal of indoor VOCs.
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APL Materials
·
2023
·Vol. 11
·期 10
·
IF 6.1
Li Xia,Deng Min,Cao Tingting,Ma Jun,Geng Shuo,Ren Yuan,Yao Mengqin,Liu Fei,Dong Yonggang
Formic acid (FA, HCOOH), as a liquid chemical hydrogen storage carrier with low cost, high hydrogen content, and convenient storage and transportation, has attracted extensive attention. Pd-based catalysts for hydrogen production from FA are easy to aggregate and deactivate in the reaction process, which hinders the further development of FA as a hydrogen storage carrier. Therefore, the exploitation of carriers with simple preparation methods and excellent performance can effectively improve the catalytic activity of Pd-based catalysts. Porous carbon and SiO 2 have been widely used for their unique structural properties, and the preparation of composite carriers by combining the advantages of both is a current research hotspot. Herein, this work synthesized C–SiO 2 for the deposition of Pd nanoparticles by a one-step method, and the obtained Pd/C–SiO 2 exhibits a superior FA dehydrogenation activity with a turnover frequency value of 1278 h −1 and a favorable stability with only a slight decrease in activity after five cycles.
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JOURNAL OF NUTRITIONAL BIOCHEMISTRY
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2022
·
IF 6.117
Qi Zhang,Wanshuang Cao,Chenying Yang,Lixia Hong,Shanshan Geng,Hongyu Han,Caiyun Zhong
The PD-1/PD-L1 immune checkpoint blockade therapy has shown revolutionary efficacy in the treatment of multiple cancers including gastric cancer. Isothiocyanates play important roles in cancer cell suppression and immunomodulation . However, the effects of isothiocyanates on immune checkpoint inhibitors are poorly understood in gastric cancer. The influence of three major isothiocyanates (sulforaphane, phenylethyl isothiocyanate, and benzhydryl isothiocyanate) on gastric cancer cell growth and PD-L1 expression was investigated. Syngeneic mouse models were administered by isothiocyanates and anti-PD-L1 monoclonal antibody , and the anti-tumor effects were assessed. The expression of PD-L1, proportion of lymphocytes and serum cytokine levels were detected to explore the underlying mechanisms. We found that PD-L1 expression was significantly induced by isothiocyanates which was associated with TAp63α up-regulation. We further revealed that TAp63α promoted PD-L1 through transcriptional activation . Combination treatment of isothiocyanates and anti-PD-L1 therapy weakened the sensitivity of gastric cancer cells to anti-PD-L1 drug. Moreover, in vivo studies illustrated that the interference effects of isothiocyanates on anti-PD-L1 antibody were related to PD-L1 expression and decreased infiltrating T lymphocytes in tumor bearing mouse hosts. Our findings provide novel insights as isothiocyanates could interfere with the successful application of immunotherapy in gastric cancer.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Nan Lu,Bin Liu,Zhengxin Peng,Jing Sui,Xiaofan Zhang,Yuting Ma,Renhong Li,Xiaoqing Yan
Rational design and fabrication of catalysts with excellent efficiency, high selectivity and outstanding stability is of great significance for the practical application of formic acid dehydrogenation into hydrogen gas. Herein, Pd catalysts with a narrow size distribution around 2.2 nm are deposited on the porous chitosan microspheres, which are produced by the polycondensation with Schiff base linkage. The Pd–N bond configuration is formed upon the abundant amino-group on the chitosan backbone with the surface anchoring Pd nanocluster. The surface charge is redistributed to generate high-valence Pd δ+ species due to the ligand-to-metal charge transfer between Pd and N, thus greatly improving the catalytic performance of formic acid dehydrogenation at room temperature and maintaining outstanding stability during 15 consecutive reaction cycles. The present work paves the way to the rational synthesis of Pd-based catalysts with tunable electronic states for practical purposes.
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Molecular Catalysis
·
2023
·
IF 4.6
Wei Tian,Yonggang Dong,Hong Qin,Ziming Luo,Qian Lin,Zheng Chen,Hongyan Pan,Yongyong Shi,Keliang Wang
The direct synthesis of hydrogen peroxide (DSHP) from hydrogen and oxygen is a green synthesis method with a high atomic economy. However, H 2 O 2 selectivity and productivity remain a key challenge, the O O bonds are easily broken with supported Pd catalysts to produce water. Herein, we report the synthesis of bimetallic catalyst PdSn@Pd@HCS by adapting reversed-phase micellar and galvanic replacement reaction. The novel bimetallic yolk-shell structure catalysts exhibit excellent catalytic performance, the selectivity and productivity of H 2 O 2 reaching 98% and 4899 mmol/g Pd· h − 1 , respectively. Theoretical calculations reveal that the presence of Sn inside the bimetallic alloy can enhance the ligand effect and optimize the electronic structure of the surface Pd atoms, weakening the adsorption ability of O 2 molecules and inhibiting the dissociation of O O bonded species, resulting in the enhancement of H 2 O 2 selectivity and productivity. This work provides the groundwork for bimetallic yolk-shell structure catalysts to achieve the efficient synthesis of H 2 O 2 .
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GREEN CHEMISTRY
·
2023
·Vol. 25
·期 15
·5999-6008
·
IF 9.8
Yuanyuan Zhang,Wanxiang Zhang,Yan Wang,Shuhang Ren,Yucui Hou,Weize Wu
To reduce the emission of NO from fossil fuel combustion and the energy consumption associated with NH3 production, the development of simple and efficient methods to transform NO into high-value-added NH3 is essential. Here, we report the efficient catalytic hydrogenation of NO to NH3 under mild reaction conditions by the synergistic catalysis of functionalized ionic liquids (FILs) and Pd catalysts. In this system, an FIL [TEPA][Im] acted as both an absorbent and a catalyst. The presence of [TEPA][Im] enhanced the catalytic performance by changing the coordination and electronic environment of Pd on the Pd/C catalyst. First, NO was absorbed by [TEPA][Im]; then, the hydrogenation of absorbed NO to NH3 was performed at a low temperature via the synergistic catalyzation of [TEPA][Im] and Pd/C. The effects of various factors on NO hydrogenation to NH3 were also investigated. Remarkably, Pd/C exhibited outstanding properties in the formation of NH3 with a high yield of 67% in the FIL [TEPA][Im] under the conditions of 100 °C and an H2 pressure of 0.5 MPa. [TEPA][Im] could be reused multiple times and the product NH3 could be recovered by flashing.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Shijie Wang,Shenghan Zhang,Zhenye Zhang,Yu Tan,Kexin Liang,Xinliang Guo,Xuhui Kong
Nitrogen heterocyclic organics are promising hydrogen storage carriers with the advantage of being capable of large-scale transportation over long distances using existing oil and gas facilities. However, traditional methods for the hydrogenation and dehydrogenation of organic hydrogen carriers usually require high temperature and pressure conditions and external hydrogen supplies, which hinder their large-scale applications, as well as having certain safety risks. In this paper, a reversible electrochemical hydrogen storage system using quinoxaline as a hydrogen carrier was developed with potential for use at room temperature and atmospheric pressure. Experiments revealed that the hydrogenation conversion of quinoxaline reached 95% within 120 min at −0.20 V vs. RHE, and the dehydrogenation conversion of 1,2,3,4-tetrahydroquinoxaline reached 100% within 30 min at 1.30 V vs. RHE. This means that the system achieved quick and efficient reversible hydrogen storage. The Pd/NF dual-function electrode prepared by spontaneous redox reaction still showed high catalytic activity after 8 cycles, indicating its good long-term stability. The proton donor in the electrochemical hydrogenation process of quinoxaline was water, which completely eliminates the safety risk from the use of external hydrogen. This work provides a simple and reliable strategy for efficient hydrogen storage using nitrogen heterocyclic organics.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Gaojie Li,Kai Du,Xinxin Wang,Xiaochen Wang,Boao Chen,Chuangwen Qiu,Jiaqiang Xu
This study is attempted to improve the hydrogen sensing performance of SnO 2 based sensors by simultaneously employing two strategies of morphology control and noble metal loading. Therefore, SnO 2 ultrathin nanosheets with thickness not exceeding 3.5 nm were successfully synthesized by a hydrothermal method and then different content of Pd nanoparticles were uniformly loaded onto SnO 2 surface by in situ reduction with ascorbic acid . The gas sensing properties demonstrated that the introduction of Pd not only altered the selectivity of the SnO 2 sensor from ethanol to hydrogen, but also significantly improved the gas sensitivity and reduced the working temperature. And the optimal 1.0%Pd/SnO 2 sensor owned the highest sensitivity (75), fastest response-recovery property (21 s/13 s) to 20 ppm of hydrogen at 220 °C, and the actual detection limit is as low as 0.1 ppm. Furthermore, 1.0%Pd/SnO 2 sensor exhibited excellent repeatability, reproducibility and acceptable anti-interference of humidity. The DFT studies suggest that the physisorption of the hydrogen molecules on the surface of SnO 2 , but chemisorption on the surface of Pd/SnO 2 . The improved H 2 sensing performance of Pd/SnO 2 sensor attributes its ultrathin thickness of SnO 2 and catalytic dissociation of Pd to O 2 and H 2 .
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MOLECULES
·
2023
·Vol. 28
·期 12
·4731
·
IF 4.6
Ailing Li,Fuping Dong,Yuzhu Xiong
Nitrogen-rich porous organic polymers were fabricated through a nonreversible ring-opening reaction from polyamines and polyepoxides (PAEs). The epoxide groups reacted with both primary and secondary amines provided by the polyamines at different epoxide/amine ratios with polyethylene glycol as the solvent to form the porous materials. Fourier-transform infrared spectroscopy confirmed the occurrence of ring opening between the polyamines and polyepoxides. The porous structure of the materials was confirmed through N2adsorption–desorption data and scanning electron microscopy images. The polymers were found to possess both crystalline and noncrystalline structures, as evidenced by X-ray diffraction and high-resolution transmission electron microscopy (HR-TEM) results. The HR-TEM images revealed a thin, sheet-like layered structure with ordered orientations, and the lattice fringe spacing measured from these images was consistent with the interlayer of the PAEs. Additionally, the selected area electron diffraction pattern indicated that the PAEs contained a hexagonal crystal structure. The Pd catalyst was fabricated in situ onto the PAEs support by the NaBH₄ reduction of the Au precursor, and the size of the nano-Pd was about 6.9 nm. The high nitrogen content of the polymer backbone combined with Pd noble nanometals resulted in excellent catalytic performance in the reduction of 4-nitrophenol to 4-aminophenol.Keywords:porous organic polymer;amine–epoxy;ring opening;catalyst carrier
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Molecular Catalysis
·
2023
·
IF 4.6
Tianyun Cui,Yu Ling,Jipeng Meng,Ke Li,Changhai Liang,Chuang Li
Nowadays, the rational design of high-performance catalysts with desirable resistance to metal leaching has become the principal challenge in the hydrogenation of nitrile butadiene rubber. In the present work, the Pd-Pt bimetallic alloy nanocatalyst exhibits an outstanding hydrogenation degree of 99.0%, obviously higher than that of the conventional monometallic Pd/SiO 2 catalyst with the same Pd content (92.9%), accompanied by approximately 100% selectivity to C=C bonds. The results reveal that electron transfer from Pt to Pd confirms that the Pd species are in a rich-electron state, which boosts hydrogen activation and improves catalytic activity. Additionally, the incorporation of inactive Pt species promotes the formation of uniformly dispersed Pd-Pt alloy nanoparticles. The incorporation of inactive Pt species can enhance the metal-support interaction, reducing the residual metal content in hydrogenated nitrile butadiene rubber. The current research demonstrates a simple procedure for designing efficient bimetallic catalysts for the hydrogenation of unsaturated elastomer.
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