BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Lian Xu,Li-Chao Wang,Bing-Mei Su,Xin-Qi Xu,Juan Lin
L-threonine transaldolase (PsLTTA) could asymmetric synthesize β-hydroxy-α-amino acids (HAAs) with excellent stereoselectivity, while the poor yield limited its further application. Here we provided a combinatorial strategy to improve HAAs production, by directed evolution of PsLTTA towards enhanced activity and introducing an acetaldehyde elimination system to avoid acetaldehyde over-accumulation. A novel high throughput screening (HTS) method for evaluating PsLTTA activity was developed and applied for directed evolution of PsLTTA. Subsequently, we co-expressed alcohol dehydrogenase and formate dehydrogenase to construct an acetaldehyde elimination system to remove acetaldehyde inhibition. Moreover, the above positive strategies were integrated. As a result, the (2S,3R)- p -methylsulfonyl phenylserine yield reached 154.0 mM and with 94.6% de value, the highest productivity and stereoselectivity of (2S,3R)-HAAs reported by enzymatic synthesis so far. Taken together, our studies provided an efficient and green route for chiral synthesis of (2S,3R)-HAAs, which might contribute to the industrialization production of these useful building blocks.
研究领域:
生物化学
·
生物技术
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 41
·期 7
·1115-1122
·
IF 3.815
Zhong Chan-Na,Liu Ya-Dong,Tang Juan,Chen Wei-Shuo,Li Shuang-Cheng,Shao Jun,Hou Hao-Qing
Blending of poly(levorotatory-lactic acid) (PLLA) and poly(dextrorotatory-lactic acid) (PDLA) produces the stereocomplex crystallites (PLA SC), which present higher melting temperature and mechanical properties than that of neat PLLA or PDLA. However, in the PLLA/PDLA blends with higher molecular weights, the phase separation occurs and the SC exhibits weak memory after melting, which lead to a small amount of SC together with a large amount of homochiral crystallites (HC) develop during crystallization from the melt. In this study, a small content of graphite oxide was blended with PLLA and PDLA to form ternary blends, and it was exciting to find that the formation of SC was enhanced gradually with the content of graphite oxide. The SC exclusively developed when 2 wt% graphite oxide was incorporated into the PLLA/PDLA, and the crystallinity with ∼50% was received even during fast cooling from the melt (−50 °C/min). The acceleration formation of SC was speculated due to the interaction between PLA molecular chains and the hydroxyl groups on the surface of graphite oxide and the obstruction of proliferation of graphite oxide.
研究领域:
高分子科学
·
材料工程
·
纳米复合材料
·
结晶动力学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Xinghao Wang,Wenrui Xiang,Siyuan Wang,Jiali Ge,Ruijuan Qu,Zunyao Wang
Soluble manganese(III), stabilized by ligands as Mn(III)-L complexes, are ubiquitous in natural waters and wastewaters and can potentially serve as both the oxidant and reductant in one-electron transfer reactions with organic contaminants. In this study, the oxidative transformations of 14 phenolic endocrine disrupting chemicals (EDCs) by in situ-formed Mn(III)-L complexes, generated from irradiated water containing Mn(II) and humic acid, were investigated. The pseudo-first-order rate constants (kobs, h–1) of these phenols varied from 1.0 × 10–4 to 5.9 × 10–2. A quantitative structure–activity relationship model was developed, which suggests that the electron-donating ability (EHOMO) of phenolic chemicals was the most important molecular characteristic for the Mn(III)-L-mediated oxidative transformation. Phenol transformation was initiated by the generation of a phenoxyl radical through electron transfer to Mn(III)-L. Subsequent self-coupling reactions between phenoxyl radicals resulted in the formation of self-coupling dimers and trimers. With the addition of simple phenol as a cosubstrate, enhanced transformations of these phenolic EDCs were clearly observed, and cross-coupling products of simple phenol and the substrates were also detected. In addition, a reaction activation energy calculation based on the transition-state theory indicated that the cross-coupling reaction was more likely than the self-coupling reaction to occur in the presence of phenol. This work provides new insights into the environmental fate of phenolic compounds.
研究领域:
环境科学
·
化学
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foods
·
2025
·Vol. 14
·期 16
·2800
·
IF 5.1
Yangzu Gao,Haoyu Li,Qian Wu,Bang Chen,Kangzhen Xu,Cong Li,Yehua Shen
The functional exploration of natural foods, coupled with the increasing prevalence of gastrointestinal motility disorders and the associated therapeutic challenges, has generated significant interest in this field. This study aims to investigate the ameliorative effects of the extract fromPugionium cornutum(L.) Gaertn (EAEPC), a traditional edible vegetable in northwest China’s desert region, on atropine-induced gastroparesis in mice, as well as to elucidate its mechanism in terms of the gut microbiota and major metabolites. The findings indicate that EAEPC effectively reduces the rate of pigment residual in the stomach while shortening the gastrointestinal transit time and alleviating other symptoms associated with atropine-induced gastroparesis. These effects may be mediated through modulation of the expression levels of major intestinal metabolites, such as short-chain fatty acids (SCFAs), bile acids (BAs), and L-tryptophan, alongside remodeling of both the diversity and relative abundance of the gut microbiota. Furthermore, correlation analyses were conducted on significantly altered strains and metabolites to clarify their interactions. Moreover, the chemical constituents of EAEPC were identified by UPLC-Q-TOF-MS/MS, and the key active components responsible for improving gastroparesis were predicted through network pharmacology approaches and validated experimentally. These results provide a foundation for further research into the functions ofPugioniumand offer scientific support for developing natural plant-based strategies aimed at treating gastrointestinal motility disorders.
研究领域:
消化病学
·
天然产物药理学
·
肠道微生态学
·
代谢组学
·
分子药理学
·
植物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CONTROLLED RELEASE
·
2014
·
IF 7.261
Haiyang Yu,Zhaohui Tang,Dawei Zhang,Wantong Song,Ying Zhang,Yan Yang,Zaheer Ahmad,Xuesi Chen
Platinum-based polymeric nano-drugs, especially cisplatin-loaded polymeric nanoparticles (CDDP-NPs), have been extensively exploited for the treatment of solid tumors . However, it is still unclear what role the processing procedure and the properties of the polymeric carrier materials may play in influencing the plasma pharmacokinetics , biodistribution and in vivo efficacy of CDDP-NPs. In this study, a series of poly( l -glutamic acid)- g -methoxy poly(ethylene glycol) (PLG- g -mPEG) copolymers were synthesized for the preparation of CDDP-loaded PLG- g -mPEG (CDDP/PLG- g -mPEG) nanoparticles . All of the parameters, including PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length, ultrafiltration purification and cisplatin loading content, were found to have a significant influence on the plasma pharmacokinetics of the CDDP/PLG- g -mPEG nanoparticles . The blood circulation time of the nanoparticles was prolonged with increases in PLG molecular weight, mPEG/PLG weight ratio, mPEG chain length and CDDP loading content. The use of ultrafiltration purification could prolong the blood circulation time of the nanoparticles as well. Experiments to measure the pharmacokinetics and biodistribution demonstrated that the selected CDDP/PLG- g -mPEG nanoparticles, NP10, had a long blood circulation time and could achieve selective and significant accumulation in Lewis lung carcinoma (LLC) tumors. The platinum plasma concentrations in the LLC tumor-bearing mice receiving NP10 remained up to 46-fold higher than that of mice receiving equivalent doses of free CDDP. In addition, the plasma area under the concentration time curve (AUC) of NP10 was 31-fold higher than that of free CDDP in 48 h. The platinum concentration ratio of NP10 to free CDDP in tumors reached as high as 9.4. The tumor AUC ratio of NP10 to CDDP was 6. Using a mouse C26 tumor model, here we demonstrate that NP10 improves the safety and tolerance in vivo when compared to CDDP and effectively inhibits the growth of C26 tumors. Furthermore, increasing the dosage of NP10 by 2 or 3-fold of free CCDP improved its anticancer efficacy to comparable or higher levels. These results indicate that CDDP/PLG- g -mPEG nanoparticles have greater potential for the treatment of solid tumors in clinical application.
研究领域:
药理学
·
肿瘤学
·
纳米医学
✓ 已验证
DOI
高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2025
·
IF 4.6
Yangzhou Xie,Sitao Wang,Yu Tian,Kexi Ye,Zhigang Xu,Han Zheng,Wei Jiang,Fengmei Zhang,Xiaoxi Si
Excessive D-lactic acid in fermented foods can result in unpleasant flavors and is difficult for the human body to metabolize. This study is the first to combine tandem column technology (C18 and Poroshell chiral-T) with a machine learning strategy. The method achieved a resolution of 2.86, with a concentration range of 50.00 μg·L −1 -50.00 mg·L −1 and a limit of detection of 16.67 μg·L −1 . We aimed to classify different lactic acid products and tobacco, and the research showed that L-lactic acid was predominant in all food analyses , while D-lactic acid was only found in lactic acid products In addition, the machine learning algorithms were optimized, and the random forest model effectively distinguished samples with similar lactic acid content. Based on this collaborative model of tandem column and machine learning, lactic acid chiral biomarkers gained the ability to classify food samples. The accuracy of model reached 80 %. This strategy contributes to the chiral analysis of lactic acid in complex food matrices. It also demonstrates the practical value of classification in food research.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
·
2020
·Vol. 31
·期 8
·1-9
·
IF 2.489
Li Wan,Hu Xueying,Chen Jiawei,Wei Zhengnan,Song Chengwu,Huang Rongzeng
The intrinsic fragility of hydroxyapatite (HAP) restricts its wider applications for local delivery of antibiotics. The composites formed by integrating HAP with hydrogels can improve the properties of HAP. However, these reported composites not only require tedious preparation and employ organic solvent and toxic reagents, but also hardly have inherent antimicrobial property. In this study, N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite (Fmoc-L-Phe/nHAP) hybrid supramolecular hydrogels with antibacterial property and cytocompatibility was prepared by integrating nHAP as reinforcement with Fmoc-L-Phe supramolecular hydrogels. The results showed that nHAP bounds in the chamber of the gel network and adheres to the fiber of Fmoc-L-Phe due to intermolecular interaction, remarkably improving the mechanical strength of Fmoc-L-Phe supramolecular hydrogels. The results of inhibition zone experiment and MTT experiment showed that the Fmoc-L-Phe/nHAP hybrid supramolecular hydrogels possess antimicrobial property and cytocompatibility. In vitro release experiment of chlorogenic acid (CGA) from the hybrid supramolecular hydrogels was performed. The study of the release kinetics indicated that the release behavior of CGA from the hybrid supramolecular hydrogels is following Weibull model and release mechanism involved Fickian diffusion and erosion of the surface of hydrogel matrix. The release of CGA shows a good inhibition effect on S. aureus . The results show that the Fmoc-L-Phe/nHAP hybrid hydrogels with antibacterial property and cytocompatibility have promising applications as drug delivery carrier.
Due to the intrinsic fragility of hydroxyapatite (HAP), the properties of HAP could be improved by incorporation into hydrogels. However, these reported composites not only require tedious preparation and employ organic solvent and toxic reagents, but also hardly have inherent antimicrobial property. We prepared N-(9-Fluorenylmethoxycarbonyl)-L-Phenylalanine/nano-hydroxyapatite (Fmoc-L-Phe/nHAP) hybrid supramolecular hydrogels by integrating nHAP as reinforcement with Fmoc-L-Phe supramolecular hydrogels. The results showed that nHAP bounds in the chamber of the gel network and adheres to the fiber of Fmoc-L-Phe due to intermolecular interaction, remarkably improving the mechanical strength of Fmoc-L-Phe supramolecular hydrogels. The results of inhibition zone experiment and MTT experiment showed that the Fmoc-L-Phe/nHAP hybrid supramolecular hydrogels possess antibacterial property and cytocompatibility. In vitro release experiment of chlorogenic acid (CGA) from the hybrid supramolecular hydrogels was performed. The study of the release kinetics indicated that the release behavior of CGA from the hybrid supramolecular hydrogels is following Weibull model and release mechanism involved Fickian diffusion and erosion of the surface of hydrogel matrix. The release of CGA shows a good inhibition effect on S. aureus . The results show that the Fmoc-L-Phe/nHAP hybrid hydrogels with antibacterial property and cytocompatibility have promising applications as drug delivery carrier.
研究领域:
材料科学
·
生物医学工程
·
药学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 26
·47599-47610
·
IF 5.6
Weijie Zhu,Weichao Wang
The rapid expansion of data-intensive technologies such as 5G, AI, and cloud computing is pushing optical communication systems to their limits, necessitating the development of advanced materials to extend bandwidth into the L- and U-bands. Fluoro-sulfo-phosphate (FSP) glasses, owing to their multi-anionic compositions and tunable network structures, offer a promising platform for next-generation broadband fiber amplifiers. In this work, a mixed-cation approach employing K + and Ba 2+ is employed to manipulate the local structural environment and enhance glass-forming ability, lifetime (8.7–9.22 ms for Er-doped, ∼10 ms for Er 3 + /Yb 3+ co-doped), emission cross-section (0.59-0.70 × 10 − 20 cm 2 ), energy transfer efficiency (∼85 %), and thermal quenching resistance. Despite their similar sizes and electronegativities, K + and Ba 2+ exhibit contrasting field strengths and polarizabilities, enabling a controlled balance between network connectivity and local disorder. Thermodynamic modeling and experimental results confirm that the introduction of mixed cations significantly broadens the glass-forming region. The addition of AlF 3 further strengthens the network, allowing for the preparation of stable K/Ba-FSP glasses with improved mechanical, thermal, and chemical properties. Spectroscopic analysis reveals a substantial enhancement in L-band emission efficiency and gain characteristics, with performance improvements ranging from 30 % to 150 % over conventional glass hosts. These findings position K/Ba-FSP glasses as a robust and high-performance candidate material system for broadband rare-earth-doped fiber amplifiers and lasers.
研究领域:
材料科学
·
光学工程
·
无机非金属材料
·
光通信
·
激光技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ying Mao,Malin Cui,Xiaoyan Zhang,Hetong Lin,Da-Peng Yang
To reduce the deterioration of fruits and vegetables caused by food-borne microorganisms, this study proposed a bio-sustainable PCD-CS photothermal bactericidal nanocomposite film. This film integrated L-Cysteine (L-Cys) coated polydopamine nanoparticles (PDA@L-Cys NPs) and deep eutectic solvents (DES) into the chitosan (CS) matrix. The DES effectively improved the mechanical property of composite film, water vapor barrier property (WVP), transparency, and biodegradability. The inclusion of PDA@L-Cys NPs significantly increased the oxidation resistance, UV-shielding, and photothermal conversion capabilities. The oxidation resistance of composite film improved 3–7 times compared to the bare CS film. Under near-infrared irradiation (NIR) for just 10 min, the temperature of the film can rise to 55.8 ℃, achieving a photothermal antibacterial rate reached 99.9% against Escherichia coli ( E. coli , ATCC 8739) and Staphylococcus aureus ( S. aureus , ATCC 6538). Under single short-time NIR trigger, the PCD-CS nanocomposite film effectively maintained good color, pH value, soluble solid content (TSS), and appearance of cherry tomato, and delayed the decrease of weight. The successful implementation of this work provides new insights and approaches for creating and advancing sustainable antibacterial food packaging.
研究领域:
食品科学
·
生物材料
·
纳米技术
·
包装工程
·
抗菌材料
·
可持续材料
·
高分子科学
✓ 已验证
DOI
高影响因子
ANALYTICAL LETTERS
·
2020
·
IF 1.467
CuiCui Liu,Xiaotong Bi,Ailin Zhang,Bin Qi,Shijie Yan
A typical l-cysteine functionalized magnetic mesoporous nanosorbent (Cys–Si–MNPs) was successfully synthesized and characterized by transmission electron microscopy, the nitrogen adsorption–desorption isotherm and X-ray photoelectron spectroscopy. The results showed that Fe3O4 magnetic core was shelled by mesoporous silica, and the capacity of thiol group with strong affinity to various heavy metal ions was as high as 238 mg g−1. Using the obtained l-cysteine functionalized magnetic nanoparticles as the adsorbent, a graphite furnace atomic absorption spectrometry (GFAAS) method was developed for the determination of Pb2+, Cd2+, Cu2+, Cr3+, and V5+ in food. The experimental parameters affecting the separation performance including the pH of the sample solution, adsorbent mass, contact time, and co-existing ions were investigated systematically. Using the optimized conditions, the detection limits were as low as from 0.006 to 0.36 μg L−1. The precision of the method was evaluated by the relative standard deviation (n = 11) at limit of quantification (LOQ) of each target ion and was less than 6.0%. The proposed method was further successfully applied for the determination of the target ions in certified reference materials including GBW10043 rice, GBW 10023 laver, and GBW 10050 shrimp. The obtained recoveries were in the range from 89% to 102% with relative standard deviations (n = 3) lower than 8%.
研究领域:
分析化学
·
环境科学
·
食品安全
✓ 已验证
DOI
高影响因子
Biomedical Physics & Engineering Express
·
2022
·Vol. 8
·期 3
·035002
·
IF 0
Siqi Li,Xiaoling Yu,Yuan Li,Tian Zhang
For nerve tissue engineering (NTE), scaffolds with the ability to release drugs under control and support the rapid proliferation of cells are very important for the repair of nerve defects. This study aimed to fabricate a conductive drug-loaded fiber mat by electrospinning and assess its potential as a scaffold for Schwann cells proliferation. The conductive polypyrrole (PPy) was coated on an electrospun poly (D, L-lactide) (PLA) fibrous mat, which was simultaneously embedded with protein-loaded chitosan nanoparticles and ibuprofen as a model small molecule drug. The fibrous mat shows suitable conductivity, mechanical properties, and hydrophilicity for NTE. For drug release and degradation studies, the fibrous mat can achieve sustained release of bovine serum albumin (BSA) and ibuprofen, and the PPy coating can increase the surface wettability and conductivity while slowing down the degradation of the fibrous mat. The application of electrical stimulation (ES) to the fibrous mat can accelerate the release of ibuprofen, but there was no significant effect on the release rate of the protein. The fibrous mat showed no cytotoxicity in vitro, and Schwann cells (SCs) can adhere, grow, and proliferate well on mats. At the 120th hour of culture in vitro, the relative growth rate of SCs on the conductive drug-loaded fibrous mat reached 198.22 ± 2.34%, which was an increase of 37.93% compared to the SCs on the drug-loaded fibrous mat with ES. The density and elongation of SCs on the conductive drug-loaded fibrous mat were greater than those on the PLA fibrous mat, indicating that the conductive polypyrrole-coated electrospun chitosan nanoparticles/PLA fibrous mat has good potential for application in nerve regeneration.
研究领域:
材料科学
·
生物医学工程
·
组织工程
·
神经科学
✓ 已验证
DOI
Journal of Macromolecular Science Part B-Physics
·
2021
·
IF 1.504
Chao Zhang,Zhihua Zhou,Wenjuan Liu,Tianlong Huang,Yanmin Zhao,Ping Chen,Ziwei Zhou,Dan Wang,Meiling Yi,Jianjun Fang
Porous microspheres have interconnecting external and internal pore structure resulting in enormous specific surface area and have drawn attention for drug delivery. In this work, poly(l-lactide-co-glycolide-co-ε-caprolactone) (PLLGC) porous microspheres were prepared by a combined solvent evaporation and particle leaching method using gelatin as a porogen. The effects of preparation parameters on the morphologies of the porous microspheres were studied. The resultant microspheres showed porous surfaces and a three-dimensional internal network structure with interconnecting pores. The porous microsphere size decreased with increasing stirring speed and decreasing PLLGC concentration. There were fewer micropores on the surfaces of the microspheres with increasing temperature. The number of the pores and pore size on the surface of the microspheres increased with increasing gelatin content. By appropriate control of these factors (stirring speed 300 rpm, PLLGC solution concentration 1.0 wt%, temperature 0 °C, and gelatin concentration 7.5 wt%), a suitable porous microsphere, with a mean diameter of 200 μm, was prepared as a potential drug delivery agent.
研究领域:
材料科学
·
高分子科学
·
药剂技术
·
生物医学工程
·
药物递送系统
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）