Materials Today Communications
·
2021
·
IF 3.383
Bushra Naureen,A.S.M.A. Haseeb,W.J. Basirun,Farina Muhamad
Tissue degeneration due to diseases, accidents, and wars is a worldwide issue. One of the methods used by regenerative medicine (RM) to aid tissue repair is by using a biodegradable tissue engineering scaffold (TES). Different body tissues have variable regeneration abilities, and hence, they require TES with variable degradation rates. This paper focuses on synthesising four polyurethane foam scaffolds (PUFS) with variable degradation rates based on the concentration of incorporated chain extender (CE) poly[(R)-3-hydroxybutyrate] (P3HB). The polyol employed is poly (propylene fumarate) (PPF) along with aliphatic 1,6-hexamethylene diisocyanate (HDI). GPC provided the molecular weight (M n = 455.67 g mol −1 , M w = 587.15 g mol −1 ) and PDI (1.29) of the PPF. FTIR and 1 H and 13 C NMR confirmed the proposed structures (C C, COOR, and NHCOO) of the PUFS. The FESEM images revealed a bimodal pore structure , with random, irregular, interconnected pores (242–340 µm) and discrete void spaces (735–860 µm). The size of PUFS pores and void spaces (PU4 > PU3 > PU2 > PU1) is directly proportional to their respective degradation rates. The TGA/DTA curves show a decrease of an onset thermal decomposition temperature from PU1 to PU4 (267.17 ºC PU1, 267.28 ºC PU2, 256.01 ºC PU3 and 240.72 ºC PU4) due to the respective increase in CE concentration. The results of in-vitro degradation analysis at day 70, revealed significant difference between the weight loss (%) of each group (PU1 = 4.09 ± 0.18%, PU2 = 8.03 ± 0.17%, PU3 = 13.14 ± 0.12% and PU4 = 20.21 ± 0.19%). Thus, PUFS with a higher concentration of P3HB have a faster degradation rate due to the associated P3HB hydrolysable ester/-COOR functional group within the PUFS backbone. The chemical structure , bimodal morphology, and variable degradation rate of these PUFS could be employed for various RM applications.
研究领域:
生物材料学
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再生医学
·
高分子化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2026
·
IF 8.7
Bin Yan,Hongru Zhao,Bingmei Su,Juan Lin
Protein engineering altered the reaction direction of TsRTA for AP. • Adjusting the catalytic center and entrance of TsRTA promoted AP binding. • A 10-site variant of TsRTA enabled biosynthesis of ( R )-1-PEA. • An acetone elimination module increased Mu10 productivity by 57.4%. ( R )-1-Phenylethylamine [( R )-1-PEA] is an important chiral compound widely used in pharmaceuticals, chemical synthesis, and materials science. ω-Transaminases are valuable biocatalysts for the asymmetric amination of ketone substrates under mild conditions and represent an attractive tool for the green synthesis of chiral amines. However, in natural ( R )-selective transaminases, acetophenone (AP) is more commonly produced as the deamination product of ( R )-1-PEA, whereas its amination as an amino acceptor is generally inefficient. In this study, an ( R )-selective ω-transaminase from Thermomyces stellatus (TsRTA), which originally catalyzed only the deamination of ( R )-1-PEA to AP, was selected as the engineering target. Protein engineering was performed to shift its reaction equilibrium, thereby enabling the asymmetric synthesis of ( R )-1-PEA from AP. To overcome the thermodynamic limitation caused by acetone accumulation, an “acetone elimination–cofactor regeneration” coupled module was introduced to improve the whole-cell catalytic efficiency for ( R )-1-PEA synthesis using AP as the substrate. Under optimal reaction conditions (35 °C, pH 10.0, 0.5 mM PLP, an isopropylamine/AP molar ratio of 4:1, 200 mM formate, and 0.2 mM NAD + ), the whole-cell catalytic system produced 67 mM ( R )-1-PEA from 100 mM AP within 8 h. This study lays a foundation for the scalable preparation of ( R )-1-PEA and provides a useful reference for regulating the reaction direction of transaminases. Download: Download high-res image (205KB) Download: Download full-size image
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Bohan Liu,Yihui Zou,Shuai Chen,Huawei Zhang,Jin Sun,Xilin She,Dongjiang Yang
Due to the high theoretical capacity and open frameworks, the low-cost sodium iron pyrophosphate Na 3.12 Fe 2.44 (P 2 O 7 ) 2 has become a promising candidate for cathode materials of the sodium ion batteries (SIBs). However, NFPO is very sensitive to moisture and CO 2 , which causes serious surface oxidation reaction and results in degraded high-rate charge/discharge performance and cyclic stability. Herein, we developed a seaweed-derived synthesis strategy to prepare air stable NFPO/r-GO aerogels by using sodium alginate (SA) and reduced graphene oxide (r-GO) as precursors. X-ray photoelectron spectroscopy (XPS) proved that there were no residual Na species on the surface of prepared NFPO/r-GO aerogels and no any oxidized impurities after exposing in air for 100 days. When evaluating the NFPO/r-GO aerogels as cathode materials for SIBs, the sample exhibits excellent reversible capacity of 116.1 mAh g −1 at 0.1 C, 88.82% capacity retention after 5000 cycles and superior rate capacity of 72.3 mAh g −1 at 20 C. The superior electrochemical performances are mainly attributed the delicate structure, which can not only increase the electronic conductivity, but also improve air stability of NFPO by suppressing surface side reactions with moisture and CO 2 .
研究领域:
材料科学
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电化学
·
能源存储
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DOI
高影响因子
DALTON TRANSACTIONS
·
2026
·
IF 3.3
Cai-Ming Liu,Yi-Quan Zhang,Xiang Hao,Xi-Li Li
It is still a major challenge to construct multifunctional complexes using axial chiral ligands. Herein, the axial chiral ligands (R)/(S)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (R-HL/S-HL) was used as a bridging ligand, and together with the Schiff base bridging ligand {H2LSchiff = [2-[(E)-(5-fluoro-2-hydroxyphenyl)methylidene]diazanyl](4-chloropyridin-2-yl)methanone}, two pairs of homochiral Dy2 complexes [Dy2(R-L/S-L)2(LSchiff)2(DMA)2]·3DMA·4H2O (R-1/S-1) and [Dy2(R-L/S-L)2(LSchiff)2(DMF)2]·3DMF (R-2/S-2) were successfully constructed at room temperature in different solvents (DMA vs DMF). Interestingly, although their coordination modes as terminal ligands are very similar, the subtle differences between DMA and DMF molecules cause changes in the space groups: R-1 and S-1 crystallize in the P1 chiral space group whereas R-2 and S-2 in the P212121 chiral space group, which may affect their nonlinear optical properties: R-1 and S-1 exhibits both SHG and THG responses, while R-2 and S-2 only displays a THG response. Notably, R-1/S-1 and R-2/S-2 are ferromagnetic coupling, and behave as single-molecule magnets (SMMs) at 0 Oe, and their magnetic properties were further studied using Ab initio calculations. Moreover, the magneto-optical effects of R-1/S-1 and R-2/S-2 were investigated by their magnetic circular dichroism (MCD) spectra.
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PubMed
高影响因子
JOURNAL OF BIOMATERIALS APPLICATIONS
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2022
·
IF 2.712
Zao Cheng,Junfei Gao,Qianqian Liu,Qun Gu
This work describes the relationship between the antibacterial activity and the ester chain length (C1-C8) of (R)-3-Hydroxybutyric ((R)-3-HB) alkyl esters that synthesized from (R)-3-HB acid ((R)-3-HBA) by esterification reaction. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) decrease as the length of the (R)-3-HB alkyl ester chain increases from 1 to 6, but (R)-3-HB-C7 and (R)-3-HB-C8 have their own rules for different microorganisms. Among them, the (R)-3HB-C6 has the relatively best antibacterial and antifungal properties, which MIC were 1.95 mg mL−1 against E. coli and S. aureus; 0.98 mg mL−1 against C. albicans and B. subtilis; 0.49 mg mL−1 against A. niger. Finally, the antimicrobial mechanisms of the (R)-3HB-C6 are revealed, and these include disruption of biofilm and the bacterial wall/membrane, leakage of the intracellular content, and change in the transmembrane potential. These results imply the potential application of (R)-3-HB alkyl ester as new antimicrobial agents; future research can use this as an antibacterial element to synthesize new polymer materials or agents with high-efficiency antibacterial activity.
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PubMed
高影响因子
PHARMACEUTICAL BIOLOGY
·
2022
·
IF 3.889
Bo Lu,Jianhua Li,MingTai Gui,Lei Yao,Mingsong Fan,Xunjie Zhou,Deyu Fu
Context Salvianolic acid B (SalB) can attenuate myocardial ischemia/reperfusion (I/R) injury, but the mechanisms are not entirely known.Objective Our study investigates if SalB protects cardiomyocytes against I/R injury by regulating Tripartite motif (TRIM) protein.Materials and methods AC16 cardiomyocytes were treated with I/R, and then with SalB (10, 25 and 50 μM) for 24 h, while control cells were cultured under normal conditions. Female Sprague-Dawley rats were subjected to I/R injury, and then intravenously injected with 20, 40, or 60 mg/kg SalB or saline, as a control, rats received sham operation and saline injection.Results Upon treatment, apoptotic rate, reactive oxygen species (ROS), and malondialdehyde (MDA) were increased 10-, 3.8-, and 1.3-fold, respectively, while superoxide dismutase (SOD) activity was reduced by 62.1% compared to control cells. I/R treatment elevated the mRNA and protein expression of TRIM8. SalB treatment remarkably abolished the above-mentioned effects of I/R treatment. TRIM8 knock-down could partially alleviate I/R-induced myocardial injury. TRIM8 overexpression promoted cardiomyocyte injury, which was alleviated by SalB. Moreover, TRIM8 negatively regulated protein expression of antioxidant enzyme glutathione peroxidase 1 (GPX1). TRIM8 protein interacted with GPX1 and TRIM8 overexpression promoted GPX1 ubiquitnation. GPX1 knock-down abolished the protective effects of SalB on I/R-injured cardiomyocytes. Our in vivo experiments confirmed the effects of SalB on I/R-induced myocardial injury.Discussion and conclusions SalB protected cardiomyocytes from I/R-induced apoptosis and oxidative stress in vitro and in vivo, which was partly mediated by the TRIM8/GPX1 axis. This suggests that down-regulation of TRIM8 expression may ameliorate I/R-induced myocardial injury.
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PubMed
高影响因子
Antioxidants
·
2022
·Vol. 11
·期 8
·1530
·
IF 7.675
Qingxiu Liu,Wenxiang Li,Shimeng Huang,Lihong Zhao,Jianyun Zhang,Cheng Ji,Qiugang Ma
The development of single enantiomers with high efficiency and low toxic activity has become a hot spot for the development and application of drugs and active additives. The aim of the present study was to investigate the effectiveness of the application of α-lipoic acid with a different optical rotation to alleviate the inflammation response and oxidative stress induced by oxidized fish oil in laying hens. Sixty-four 124-week-old Peking Red laying hens were randomly allocated to four groups with eight replicates of two birds each. The normal group was fed basal diets supplemented with 1% fresh fish oil (FO), and the oxidative stress model group was constructed with diets supplemented with 1% oxidized fish oil (OFO). The two treatment groups were the S-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + S-LA) and the R-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + R-LA) added at 100 mg/kg, respectively. Herein, these results were evaluated by the breeding performance, immunoglobulin, immune response, estrogen secretion, antioxidant factors of the serum and oviduct, and pathological observation of the uterus part of the oviduct. From the results, diets supplemented with oxidized fish oil can be relatively successful in constructing a model of inflammation and oxidative stress. The OFO group significantly increased the levels of the serum inflammatory factor (TNF-α, IL-1β, IL-6, and IFN-γ) and the oxidative factor MDA and decreased the activity of the antioxidant enzyme (T-AOC, T-SOD, GSH-Px, GSH, and CAT) in the oviduct. The addition of both S-LA and R-LA significantly reduced the levels of serum inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), increased the activity of antioxidant indexes (T-AOC, T-SOD, GSH-Px, GSH, and CAT), and decreased the MDA contents in the serum and oviduct. Meanwhile, the supplementation of S-LA and R-LA also mitigated the negative effects of the OFO on the immunoglobulins (IgA and IgM) and serum hormone levels (P and E2). In addition, it was worth noting that the R-LA was significantly more effective than the S-LA in some inflammatory (IL-1β) and antioxidant indices (T-SOD, GSH, and CAT). Above all, both S-LA and R-LA can alleviate the inflammation and oxidative damage caused by oxidative stress in aged laying hens, and R-LA is more effective than S-LA. Thus, these findings will provide basic data for the potential development of α-lipoic acid as a chiral dietary additive for laying hens.Keywords:S-form of α-lipoic acid;R-form of α-lipoic acid;oxidized fish oil;antioxidant;laying hen
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高影响因子
Catalysts
·
2021
·Vol. 11
·期 9
·1126
·
IF 4.146
Qingman Li,Qihua Jiang,Pengcheng Gu,Lianju Ma,Yiwu Wang
Ni2+-NTA-boosted magnetic porous silica nanoparticles (Ni@MSN) to serve as ideal support for bi-functional enzyme were fabricated for the first time. The versatility of this support was validated by one-step purification and immobilization of bi-functional enzyme MLG consisting of 3-Quinuclidinone reductase and glucose dehydrogenase, which can simultaneously catalyze both carbonyl reduction and cofactor regeneration, to fabricate an artificial bi-functional nanobiocatalyst (namely, MLG-Ni@MSN). The enzyme loading of 71.7 mg/g support and 92.7% immobilization efficiency were obtained. Moreover, the immobilized MLG showed wider pH and temperature tolerance and greater storage stability than free MLG under the same conditions. The nanosystem was employed as biocatalyst to accomplish the 3-quinuclidinone (70 g/L) to (R)-3-quinuclidinol biotransformation in 100% conversion yield with >99% selectivity within 6 h and simultaneous cofactor regeneration. Furthermore, the immobilized MLG retained up to 80.3% (carbonyl reduction) and 78.0% (cofactor regeneration) of the initial activity after being recycled eight times. In addition, the MLG-Ni@MSN system exhibited almost no enzyme leaching during biotransformation and recycling. Therefore, we have reason to believe that the Ni@MSN support gave great promise for constructing a new biocatalytic nanosystem with multifunctional enzymes to achieve some other complex bioconversions.Keywords:porous silica nanoparticles;immobilized enzyme;nanosystem;cofactor regeneration;(R)-3-quinuclidinol;biocatalysts’ recycling
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 7
·9032-9043
·
IF 2.478
Liu Yunyi,Pan Yongqi,Bai Xudong,Wang Jinchuan,He Caiwang,Xu Zunping,Chen Yi
A conventional ceramic preparation method was used to fabricate the newly designed ternary (K,Na)NbO 3 -based lead-free ceramics, which have the general formula of (0.97- x )K 0.40 Na 0.60 Nb 0.95 Sb 0.05 O 3 –0.03Bi 0.5 K 0.5 HfO 3 – x SrZrO 3 . An X-ray diffraction analysis, together with dielectric-temperature measurements, was performed for determining their phase structures. The crystal structure was found to transition from a rhombohedral-orthogonal phase coexistence to a three-phase coexistence of rhombohedral-orthogonal-tetragonal phases with the increase in SrZrO 3 concentration, and then to a rhombohedral-tetragonal phase coexistence, and finally to a single rhombohedral phase. Near the three-phase coexistence zone, the ceramics exhibit an obviously enhanced electrical activity, with an electromechanical coupling coefficient k p = 0.364 and a piezoelectric constant d 33 = 280 pC/N. Through a microstructure analysis, a slightly excessive amount of SrZrO 3 was found to result in an inhibition for the grain growth of the studied ceramics. These results show that incorporating SrZrO 3 into ternary (K,Na)NbO 3 -based ceramics is still an effective means of constructing phase boundaries and improving the electromechanical properties.
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高影响因子
MICROCIRCULATION
·
2020
·Vol. 28
·期 4
·e12675
·
IF 2.11
Qingbo Shao,Jing Xia,Pinwen Wu,Jiazhou Ying
Background Dexmedetomidine (Dex) exerts an effective therapeutic role in numerous diseases associated with ischemia/reperfusion (I/R) injury via its anti‑apoptosis properties. Therefore, this study explores the cardioprotective effects of Dex in cardiac microvascular endothelial cells (CMECs) in response to oxygen-glucose deprivation and re-oxygenation (OGD/R) injury and its potential mechanism. Material and methods CMECs were pretreatment with different concentration of Dex, then exposed to OGD/R. Cell viability was measured with CCK-8 assay. Apoptosis was evaluated by flow cytometry, and apoptosis-related protein was determined by Western blot. Autophagy was assessed by transmission electron microscopy and autophagy-related proteins. Besides, the role peroxisome proliferator-activated receptors (PPARδ) in Dex-mediated anti-apoptosis property was validated with agonist and antagonist. Results OGD/R significantly decreased cell viability, increased reactive oxygen species, caused disorder of autophagy, and increased apoptosis in CMECs. Dex enhanced the viability of the OGD/R-treated CMECs and effectively decreased reactive oxygen species production. Autophagy in CMECs was activated by Dex, as evidenced by the increase in the ratio of LC3B-II/I, expression level of Beclin1 and number of autophagosomes in the OGD/R-induced CMECs. The mechanistic investigation indicated that PPARδ antagonist GW501516 aggravated cell damage following OGD/R, while PPARδ agonist GW6471 partly abolished the Dex-mediated protective effects. Conclusions Dex activated the PPARδ-AMPK-PGC-1α pathway-mediated autophagy in CMECs, therefore to inhibit excessive apoptosis induced by OGD/R. Dex may potentially be a therapeutic intervention for myocardial I/R injury.
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高影响因子
Journal of Oceanology and Limnology
·
2017
·Vol. 36
·期 2
·473-482
·
IF 0
Gong Yanhui,Ma Sanmei,Wang Yongfei,Xu Yongkai,Sun Aijun,Zhang Yun,Hu Yunfeng
A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC10 was characterized. At present, the reports about the kinetic resolution of racemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate ( R )-methyl 2-chloropropionate with high enantiomeric excess (>99%) after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration (80 mmol/L) of esterase EstC10 was higher than the kinetic resolution of another esterase, Est12-7 (50 mmol/L). The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of ( R )-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.
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Analytical Methods
·
2014
·Vol. 6
·期 10
·3474-3481
·
IF 1.938
Yuanzhen Zhou,Weimin Tang,Jing Wang,Guo Zhang,Shouning Chai,Liang Zhang,Ting Liu
A sensitive and selective method based on a poly(alizarin yellow R)-modified carbon paste electrode (PAYR/CPE) to detect dopamine (DA) and uric acid (UA) was successfully established. The morphology of the electrode surface was observed by scanning electron microscopy (SEM). Electrochemical characterization of the PAYR/CPE was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was illustrated that the PAYR/CPE had excellent electro-catalytic ability toward the oxidation of DA. The anodic peak current of DA was greatly enhanced at the PAYR/CPE, and the standard rate constant (ks) was calculated to be 6.17 s−1. The linear calibration curves were obtained as 0.49–70.1 μM and 83.6–488.1 μM for DA and 27.8–304.4 μM and 381.6–1118 μM for UA by DPV. The detection limits were 0.16 μM for DA and 9.5 μM for UA. Moreover, the modified electrode was applied to the selective detection of DA and UA with high sensitivity and selectivity. Furthermore, the modified electrode displayed high reproducibility and stability for determination of these species. Thus, the proposed electrode could be conveniently employed for the determination of DA and UA in real samples and provide satisfactory results.
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高影响因子
危险品化学品经营许可证（带存储）