ACS Applied Materials & Interfaces
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2023
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IF 9.5
Rui Du,Bin Zhao,Kun Luo,Man-Xi Wang,Quan Yuan,Lei-Xiao Yu,Ke-Ke Yang,Yu-Zhong Wang
Bone tissue engineering involving scaffolds is recognized as the ideal approach for bone defect repair. However, scaffold materials exhibit several limitations, such as low bioactivity, less osseointegration, and poor processability, for developing bone tissue engineering. Herein, a bioactive and shape memory bone scaffold was fabricated using the biodegradable polyester copolymer’s four-dimensional fused deposition modeling. The poly(ε-caprolactone) segment with a transition temperature near body temperature was selected as the molecular switch to realize the shape memory effect. Another copolymer segment, i.e., poly(propylene fumarate), was introduced for post-cross-linking and improving the regulation effect of the resulting bioadaptable scaffold on osteogenesis. To mimic the porous structures and mechanical properties of the native spongy bone, the pore size of the printed scaffold was set as ∼300 μm, and a comparable compression modulus was achieved after photo-cross-linking. Compared with the pristine poly(ε-caprolactone), the scaffold made from fumarate-functionalized copolymer considerably enhanced the adhesion and osteogenic differentiation of MC3T3-E1 cells in vitro. In vivo experiments indicated that the bioactive shape memory scaffold could quickly adapt to the defect geometry during implantation via shape change, and bone regeneration at the defect site was remarkably promoted, providing a promising strategy to treat bone defects in the clinic, substantial bone defects with irregular geometry.
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ACS Applied Polymer Materials
·
2023
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IF 5
Xiaobo Xu,Xiaozhen Ma,Xiaolin Wang,Jin Zhu,Jinggang Wang,Ning Yan,Jing Chen
Using sustainable biomass feedstock to prepare biobased chemical products is attracting increasing attention. Betulin is a natural cyclic aliphatic diol that can be extracted in large quantities from the bark of birch trees. In this study, a series of bio-based polyurethane (PU) elastomers with excellent mechanical properties, solvent resistance, and thermal stability were synthesized under catalyst-free conditions using betulin and castor oil (CO) as the bio-based polyols. The chemical structure and properties of the bio-based PU elastomers were systematically investigated according to the effect of the hydroxyl ratio between betulin and CO. Due to the presence of abundant hydrogen bonds and rigid ring planes in the PU structure, and a higher cross-link density, the obtained PU elastomers had excellent mechanical properties. They achieved a maximum tensile strength of 31.6 MPa with the tensile strain reaching more than 200% and were able to withstand 1 × 105 times their weight. The thermal decomposition temperature of the betulin-derived PUs was over 300 °C. This study showcased a strategy to synthesize sustainable high-performance PU materials with a high biomass content (>75%).
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EUROPEAN POLYMER JOURNAL
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2023
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IF 6
Gaojie Wu,Shengli Qi,Guofeng Tian,Dezhen Wu
In order to solve the challenge of balancing the thermoplastic processing properties and thermal dimensional stability of polyimide (PI) resin, in this research, 3,3′,4,4′-biphenyl tetracarboxylic diandhydride (BPDA) and 2,2′-bis(trifluoromethyl)benzidine (TFMB) were used as rigid components, 4,4′-oxydiphthalic anhydride (ODPA) and 4,4′-diaminodiphenyl sulfone (DDS) as flexible components. A series of random copolyimide resins was prepared by adjusting the molar ratio of rigid and flexible monomers. Determining the molar ratio which could balance the thermoplastic processing properties and thermal dimensional stability, block copolyimide resins with different rigid and flexible block lengths were then prepared in this ratio. The research showed that the molar ratio of monomers and the sequence structure of molecular chains had a strong influence on the performance of PI resins. When the content or block length of rigid component increased, the coefficient of thermal expansion (CTE) decreased but the glass transition temperatures ( T g ) and melt viscosity increased. The PI-B343 resin had a CTE value of 40.63 ppm/K and the lowest melt viscosity reached 675 Pa·s, achieved the simultaneous regulation of the thermoplastic processing properties and thermal dimensional stability for PI resin.
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NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 36
·17072-17079
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IF 3.3
Hongmei Xie,Guozhi Zhu,Dawei Ye,Weiquan Cai,Junjie Zhang,Kangping Huang,Yuliang Mai,Bing Liao,Jiazhi Chen
Catechyl lignin (C-lignin) is a unique and attractive natural biopolymer used as raw material for the production of chemicals and materials due to its homogeneous linear aromatic structure. Tung nutshells, an important component of industrial solid waste, are rich in C/G-type Lignin. Herein, for the first time, we report that the catalytic oxidation strategy is effective for the conversion of Tung nutshell lignin to value-added C/G-type aromatic monomers using the commercially available CuCl2 catalyst. The reaction conditions, including solvent, temperature, and catalyst dosage, were comprehensively investigated. The optimal yield of 60.8 mg g−1 (or 12.9 wt% Klason lignin) C/G-type aromatic aldehydes and acids was obtained using the CuCl2 catalyst in the CH3CN/H2O (8/2, v/v) solvent mixture at 190 °C for 4 h. The C-type aromatic monomers were formed with an yield of 7.7 mg g−1 (or 1.6 wt%) in the initial 0.2 h and gradually decreased as the reaction progressed. The less amount of C-type lignin-derived aromatic monomers can be attributed to their lower thermal stability under oxidative conditions. The structural evolution study of lignin by GPC and HSQC NMR reveals that the C/G units are effectively depolymerized and transformed into aromatic aldehydes and acids by the CuCl2/CH3CN/H2O catalytic oxidative system.
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ACS Catalysis
·
2023
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IF 12.9
Xugang Yang,Zaihao Yuan,Minghao Zhou,Feng Chen,Bo-Qing Xu,Hui Shi
Lewis acidic heterogeneous catalysts are known to be active for transfer hydrogenation of carbonyl compounds, which occur naturally or can be derived from renewable feedstocks. While previous studies have explored a myriad of Zr-based catalytic systems toward the Meerwein–Pondorf–Verley (MPV) reductions, few have determined intrinsic, site-specific rates under strict kinetic control across a sufficiently wide range of process conditions, causing misconceptions about the true potentials of these catalysts for the targeted transformations. Here, we present a quantitative assessment on the intrinsic activities of four types of Zr catalysts that are purportedly promising candidates for the MPV reductions; the selected catalysts contain active Zr sites within diversified local coordination and secondary solvating environments. A comprehensive kinetic study of ethyl levulinate (EL) MPV reduction in 2-butanol, combined with in situ quantitative titration of the active sites by selective poisoning with alkylphosphonic acid titrants of Lewis acid sites during the reaction, reveals dramatic differences in the relative fraction of active sites (13–78% of total Zr) and turnover rates (>300-fold) among the studied catalysts. Mechanistically, the hydride shift invariably remains as the sole rate-limiting step, regardless of the catalyst; the free energy barriers in both first-order and zero-order kinetic regimes and kinetic isotope effects, however, differ significantly among the catalysts. Through mechanism-based rate equations and transition-state-theory treatments, we further delineate that the wide variations in enthalpic and entropic components not only suggest disparate transition state structures and energetics but also reflect varying adsorption thermodynamics that are influenced by both reactant coordination at and solvent restructuring near the active sites.
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International Journal of Electrochemical Science
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2023
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IF 1.5
Yinze Zuo,Liang Chen,Yu Wang,Yunxia Guo,Xingling Shi,Yanmin Gao
Pre-processing of a metal surface before coating is a key factor that affects the coating performance. This phenomenon has been puzzling people for a long time. In this paper, a new type of preprocessing using heterocyclic compounds, pyridine and furan, were applied to address this problem. The tests show that the rust layers of mild steel treated by pyridine and furan are more compact than the untreated layers. The corrosion rate of the mild steel with a rust layer treated by pyridine is lower than that of the samples with furan treatment and without treatment, while the impedance is also the largest. The adhesion of an epoxy-polyvinylbutyral (EP-PVB) coating, which is painted on rust layers with pyridine and furan pretreatment, is much stronger. Moreover, the corrosion resistance of EP-PVB coatings that are painted onto the rust layers with pretreatment is much better than that of the coatings that are directly painted onto the rust layer without pretreatment. The impedance of EP-PVB coatings that are painted onto the rust layers with pretreatment is much higher than that of the EP-PVB coating that is directly painted onto the rust layer without pretreatment.
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International Journal of Electrochemical Science
·
2023
·
IF 1.5
Hu Wang,Jun Tang,Juan Xie
Corrosion inhibition effects of asymmetric gemini corrosion inhibitor on N80 steel in a CO 2 -saturated brine solution had been investigated by weight loss and electrochemical measurements. The synergistic effects of gemini with thiourea (TU), thiazole (TZ) and pyridine (PD) were also studied with weight loss and electrochemical measurements. The results revealed that asymmetric gemini corrosion inhibitor displayed excellent corrosion inhibition performance at 70°C in CO 2 -saturated brine solution. The inhibitor was anodic type in nature. There existed apparent synergistic effect between asymmetric gemini inhibitor and other ingredients. The mixture inhibitors can provide excellent protection to N80 steel at test condition. The best formula of mixture inhibitors was then presented. The synergistic mechanism of gemini with other ingredients were also discussed.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Weilong Hou,Kehang Lin,Xiangyu Zhang,Bowen Xu,Yuexia Wang,Xinqing Lu,Yijing Gao,Rui Ma,Yanghe Fu,Weidong Zhu
Nonoxidative propane dehydrogenation (PDH) has been regarded as an economic and efficient route to meet constantly increasing global demands for propylene. However, over industrially applied catalysts, thermally induced deactivation including coke formation and sintering of the active species occurs and simultaneously hydrocarbon cracking significantly reduces the selectivity for propylene. In the present work, titanosilicate-1 (TS-1) zeolite supported catalysts (Pt/TS-1) were developed for PDH. The results on the extensive characterizations of the prepared materials, in combination with density functional theory (DFT) calculations, verify that the framework Ti species in Pt/TS-1 can increase the dispersion and electron density of Pt, which significantly enhances the catalyst stability and selectivity for propylene. Utmost importantly, no sintering of the Pt active species in Pt/TS-1 occurs at the high temperatures required for the reaction and catalyst regeneration processes. Therefore, the current investigation provides a strategy for developing efficient PDH catalysts for practical applications.
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ACS Applied Nano Materials
·
2023
·
IF 5.9
Sizhao Zhang,Jing Wang,Zhao Wang,Guangyu Xu,Yonggang Jiang,Yunyun Xiao,Feng Ding
Reusable nanoporous polyimide (PI) aerogels are rather promising for highly efficient thermal insulation of future thermal protection systems demanded in aerospace and domestic applications. However, the development of high-performance PI aerogels is limited by their unsatisfactory high-temperature resistance and poor reusability. Herein, an Al2O3-hybridization strategy toward PI aerogels is demonstrated, and the formed aerogels exhibit a nanoporous structure, unusual reusability, and exceptional high-temperature resistance. Furthermore, the aerogels retain their high-level properties such as the very small changing rates of mass (≤0.3%), shrinkage (≤2.53%), thermal conductivity (≤3%), and bulk density (near-zero difference) even after five cycles of high-temperature assessment (250 °C for 2400 s). The conventional huge heat-induced shrinkage of PI aerogels could be substantially restrained even bearing a high-temperature environment, realizing near-zero thermally insulating degradation, which has an outstanding practical application value. The high-temperature resistance of the aerogel is greatly improved by the Al–O network constructed inside the PI aerogels, and this resistance is retained even after multiple cycles under harsh conditions, ultimately affording superior reusability to PI aerogels for the first time. The high-temperature resistance and ultralow heat-induced shrinkage properties of aerogels, as well as their reusability, make them favorable candidates as thermal protection materials for the future development of aircraft and military.
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ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Guiquan Liu,Guorong Wang,Zhiliang Jin
Porous carbon is an ingredient for energy transformation and collection systems in terms of electrochemistry. As a new member, graphdiyne (GDY) gradually began to be concerned because of its especially compositional and structural properties. Herein, a lamelliform GDY was successfully prepared by cross-coupling strategy under the catalysis of cuprous iodide. Thanks to the sp and sp 2 hybrid carbon networks, the obtained GDY nano-lamellas promote excellent performance in the electrode of supercapacitors with a gravimetric capacitance of 137.8 F g − 1 at a mass-specific current of 1 A g − 1 , and a relatively good rate performance of 81.28% when the mass-specific current reach to 20 A g − 1 . In addition, the capacitance of the GDY electrode barely decays during the 11,000 cycles of repeated testing. This enables the assembled symmetric supercapacitor provides a acceptable energy density of 6.11Wh kg −1 under a power density of 5500W kg −1 , and with an average decay of 0.5% per cycle at the end of 5000 cycles. The relatively good electrochemical stability of this GDY nano-lamellas material will open the further promotion of graphdiyne-based electrodes in the domain of supercapacitors.
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Communications Biology
·
2023
·Vol. 6
·期 1
·1-12
·
IF 5.9
Wang You-Yuan,Zhen Cheng,Hu Wei,Huang Hui-Huang,Li Yan-Jun,Zhou Ming-Ju,Li Jing,Fu Yu-Long,Zhang Peng,Li Xiao-Yu,Yang Tao,Song Jin-Wen,Fan Xing,Zou Jun,Meng Si-Run,Qin Ya-Qin,Jiao Yan-Mei,Xu Ruonan,Zhang Ji-Yuan,Zhou Chun-Bao,Yuan Jin-Hong,Huang Lei,Shi Ming,Cheng Liang,Wang Fu-Sheng,Zhang Chao
CD8 + T cells are essential for long-lasting HIV-1 control and have been harnessed to develop therapeutic and preventive approaches for people living with HIV-1 (PLWH). HIV-1 infection induces marked metabolic alterations. However, it is unclear whether these changes affect the anti-HIV function of CD8 + T cells. Here, we show that PLWH exhibit higher levels of plasma glutamate than healthy controls. In PLWH, glutamate levels positively correlate with HIV-1 reservoir and negatively correlate with the anti-HIV function of CD8 + T cells. Single-cell metabolic modeling reveals glutamate metabolism is surprisingly robust in virtual memory CD8 + T cells (TVM). We further confirmed that glutamate inhibits TVM cells function via the mTORC1 pathway in vitro. Our findings reveal an association between metabolic plasticity and CD8 + T cell-mediated HIV control, suggesting that glutamate metabolism can be exploited as a therapeutic target for the reversion of anti-HIV CD8 + T cell function in PLWH.
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Arabian Journal of Chemistry
·
2023
·
IF 6
Yuan Lin,Yimin Zhang,Zhuang Xiong,Min Wu,Muling Zeng,Chuangnan Li,Fujin Liu,Yazhi Liao,Chunping Liu,Jing Chen
In this study, we successfully synthesized a novel glycyrrhetinic acid (GA) derivate compound as a liposomal carrier. Glycyrrhetinic acid-diaminododecane-cholesterol (GA-DA-CH) was synthesized from GA, diaminododecane, and cholesteryl hemisuccinate by two-step amidation under catalytic conditions. The chemical structures of GA-DA (glycyrrhetinic acid-diaminododecane) and GA-DA-CH were confirmed by Mass Spectrum (MS), Nuclear Magnetic Resonance (NMR) spectrometer, and analyzed by Fourier Transform Infrared spectroscopy (FTIR), High-Performance Liquid Chromatography (HPLC). Glycyrrhetinic acid ligand-modified liposomes (GA-DA-CH-Lips) were prepared, consisting of egg phosphatidylcholine, cholesterol and GA-DA-CH. GA-DA-CH was integrated into the liposomal capsule to promote hepatocellular carcinoma targeting. The particle size of GA-DA-CH-Lips was calculated to be between 122.87 and 133.30 nm, with an approximate polydispersity index (PDI) was 0.20, and a zeta potential was in the range of –32.50 to –26.53 mV. GA-DA-CH-Lips were constructed with more than 90% encapsulation efficient and drug loading efficiency of no<6.40%. In addition, environmental stability assays show that GA-DA-CH-Lips are sensitive to temperature, and thus should be preserved at low temperatures. Furthermore, in vitro cellular uptake from qualitative and quantitative analysis indicates that GA-DA-CH integrating into liposomes possess a specific target for hepatocellular carcinoma. Intracellular inhibition showed that GA-DA-CH-Lips effectively inhibited cell proliferation in dose-dependent features. Based on these results, we have reason to believe that GA-DA-CH-Lips could be a potential hepatic target drug delivery to improve the therapeutic effect of hepatic diseases.
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