APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2014
·Vol. 172
·期 6
·3287-3296
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IF 1.687
Yu Tingting,Cao Xuejun
Chaotropes could significantly enhance lipase activity recovery in reverse micellar back extraction. However, the mechanism of chaotropes promoting the release of enzyme from reverse micelles was not clear. In this study, chaotropes were added in the process of lipase reverse micellar extraction, and back extraction recovery was improved. In back extraction, at 0.6 M urea in stripping solution, 94.60 % total extraction recovery was obtained. Meanwhile at 0.3 M guanidine hydrochloride, nearly 65 % lipases were released into the stripping solution. DLS and Karl Fischer method results showed that the presence of urea in stripping solution could weaken the electrostatic interaction between lipase and cetyltrimethylammonium bromide molecules, promoting lipase release from reverse micelles, and guanidine hydrochloride could stimulate lipase and free water molecules enwrapped in reverse micelle release into the stripping solution. These experimental results provide a clue for understanding the mechanism of chaotropes influencing on protein recovery in reverse micelle back extraction.
研究领域:
生物化学
·
酶工程
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DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 36
·20715-20727
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IF 3.049
Hong-Li Zhang,Bing-Hua Liu,Mingbo Yang,Pan Zhang,Jing-Gang Gai
A novel sulfaguanidine (SG)-modified polyamide thin-film composite (TFC) nanofiltration (NF) membrane was constructed by the strategy referred to as co-solvent assisted interfacial polymerization (CASIP), which involves the respective interfacial polymerization (IP) of piperazine (PIP) and SG with trimesoyl chloride (TMC) on porous polysulfone (PSf) supports. CASIP enables the formation of a defect-free thin dense active layer and favors higher water permeance up to 79.0 L m−2 h−1 with rejection above 98.3% for Na2SO4. The resulting PA membrane also demonstrates a high flux recovery ratio of nearly 98.9% to bovine serum albumin protein after being cleaned. More importantly, the current membrane shows excellent anti-adhesive and antimicrobial performances against Gram-negative Escherichia coli, Gram-positive Bacillus pumilus LDS.33 and Aspergillus parasiticus JFS. This promises great potential application of the PA membrane for practical water/wastewater treatment. The prospect of using the co-solvent mediated SG-modified layer as a next-generation anti-fouling/antimicrobial membrane is very encouraging.
研究领域:
环境科学
·
材料科学
·
微生物学
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DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2016
·Vol. 32
·期 4
·630-633
·
IF 1.086
Zhu Jian,Jin Zhimin
After being hydrolyzed into corresponding hydrosoluble carboxylate by 1,1,3,3,-tetramethylguanidine (TMG), camptothecin was extracted via the aqueous two-phase systems composed of ionic liquid 1,1,3,3-tetramethylguanidinium(TMGM) carboxylate and K 2 CO 3 , and was regenerated at the final by dilute aqueous hydrochloric acid. Among the ionic liquids, TMGM benzoate showed the best effect, TMGM formate the worst, this results were consistent with the liposolubilities of different carboxylic acid components in the ionic liquids. Through two-step extraction of TMGM benzoate ionic liquid/K 2 CO 3 aqueous two-phase at a favorable condition, camptothecin was obtained in a purity of 98.3% and a total yield of 85.1%, from the crude camptothecin extract with a purity of 14.2%.
研究领域:
药学
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分离科学
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2021
·
IF 7.46
Yuan Li,Hongtao Wang,Yueying Liu,Yueyue Li,Chenchang Wang,Jihao Bai,Lin Yang,Yilin Wang,Fengmin Liu,Xishuang Liang,Geyu Lu
Bimetallic nanocrystals (NCs) have received a lot of attention due to its excellent catalytic performance. Here, PtRu NCs were successfully synthesized by ethylene glycol and used to modify flower-like WO 3 which was prepared via a simple hydrothermal method . The morphology and structure of the as-synthesized materials were characterized, and the performance of the gas sensor based on PtRu NCs decorated WO 3 was carefully studied. The gas sensing investigation showed that there was a significant improvement in response after PtRu NCs being introduced. Among all samples, the WO 3 sample modified with 0.4 wt% PtRu NCs showed the highest response to xylene at 170 °C (Ra/Rg = 261), which is almost 75 times than that of pristine WO 3 . In addition, it also presented fast response speed (2 s), good selectivity to xylene and excellent repeatability. The possible sensitization mechanism was proposed, the improvement of sensing performance could be ascribed to the high catalytic activity of PtRu NCs, and the regulation of depletion layer by Schottky barrier and heterojunction at the contact interface between WO 3 and PtRu NCs. This work can be promising for rapid detection of xylene for environmental protection at low temperature.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
FREE RADICAL RESEARCH
·
2020
·
IF 2.839
Jian Li,Jiaojiao Wang,Weiwei Liu,Toshihiko Hayashi,Kikuji Itoh,Satoshi Onodera,Takashi Ikejima
Bleomycin is a glycopeptide antibiotic that is widely employed in the therapy of a range of lymphomas and germ cell tumours. But the therapeutic efficacy of bleomycin is limited by development of lung fibrosis. The cytotoxicity of bleomycin is mostly ascribed to mitochondrial DNA (mtDNA) damage, while a protective effect of metformin against bleomycin-induced lung fibrosis results from the inhibition of mitochondrial complex I. Since mitochondria and bacteria have certain similarities in structure and function, we used Escherichia coli for simplification in the present work to investigate the relationship between metformin and bleomycin with apparently opposite effects on mitochondrial DNA damage. Bleomycin lethality to E. coli was ameliorated by metformin treatment accompanying further increase of the level of reactive oxygen species. Catalase but not superoxide dismutases attenuated the protective effect of metformin. Meanwhile, treatment with hydrogen peroxide enhanced the protection, indicating that metformin may protect E. coli from bleomycin-induced bactericide via enhanced generation of hydrogen peroxide. Moreover, silibinin, a hepatoprotective polyphenolic flavonoid attenuates the cytotoxicity of bleomycin to E. coli via enhanced generation of hydrogen peroxide as well. This bacterial model in place of mitochondria can provide us with easier screening for the molecules with capability of reducing the bleomycin side effect.
研究领域:
微生物学
·
药理学
·
医学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 93
·90777-90785
·
IF 3.289
Li Wang,Zongbao Liu,Xiaofei Liu,Yuntang Wu
With reference to the molecular structure of metformin, a new biguanide compound, namely, chitooligosaccharide guanidine (COSG), was synthesized by microwave irradiation. It could both reduce the stimulatory effect of metformin on the gastrointestinal system and increase the biological activity of the drugs. Then, a cell vitality test was conducted to examine the cell toxicity of chitooligosaccharide (COS) and COSG, and an insulin resistance (IR) model using L6 skeletal muscle cells was established. The influence of COS and COSG on the cell vitality and glucose consumption of IR cells was observed and compared with that of metformin and insulin. Moreover, the expression and translocation of GLUT4 protein and the phosphorylation level of Akt were further investigated to study the mechanism. The results showed that both COS and COSG were non-toxic and could improve the vitality and promote the uptake of glucose of L6 cells remarkably in comparison to metformin. Furthermore, the effect of COSG on promoting glucose uptake was better and dose-dependent. It was also found that COS could increase the total expression of GLUT4 protein but had no significant effect on the membrane translocation of GLUT4, whereas metformin exhibited little effect on either the total expression or the membrane expression of GLUT4. Moreover, COSG exerted little influence on the total expression of GLUT4 protein but led to significant improvement in the membrane expression of GLUT4 and phosphorylation level of Akt, which were consistent with the effect of insulin.
研究领域:
药理学
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细胞生物学
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生物化学
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Bin Liu,Xinyue Cui,Xiaozhen Lu,Xuewu Zhu,Lin Wang,Junyong Zhu
Positively charged polyamide (PA) nanofiltration (NF) membranes with sub-nanopores show promise for lithium extraction from salt-lake brines with high Mg 2+ /Li + ratios. This study introduces the use of triamino guanidine (TG), a highly positively charged molecule, to regulate grafting on monolayer PA membranes, resulting in dual-layer (PEI-TMC-TG) NF membranes. The monolayer PA membranes were created via spin-coating assisted interfacial polymerization between polyethyleneimine (PEI) and tricarbonyl chloride (TMC). The PEI/TMC-TG NF membranes exhibited several advantages over unmodified PEI-TMC NF membranes, including higher positive charge density, narrower pore size distribution, excellent hydrophilicity, and a more porous separation layer microstructure. Experimental results indicated that enhanced Donnan effect, size sieving, and dielectric repulsion within the sub-nanopores contributed to exceptional Li + /Mg 2+ selectivity during filtration of East Taijiner brine (S Li + /Mg 2+ = 64.5). Furthermore, the TG hydrophilic layer significantly improved water permeability (15.4 LMH/bar) and long-term stability. To reduce membrane fouling in the charge-positive NF process by removing organic matter from complex salt lake brine, we explored electrocoagulation as a pre-treatment method and identified optimal conditions for the EC-NF process. This strategy maximizes sustainable lithium recovery from brine in an economically viable green manner while enhancing the efficiency of NF membranes for lithium extraction from salt lakes.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yunhao Li,Haijun Yu,Lixin Li,Yanfang Liu,Guodong Kang,Xinmiao Liang,Yiming Cao
The utilization of nanofiltration membranes for lithium extraction from Salt-Lake holds the potential to address lithium resource scarcity and drive energy transformation. Nevertheless, the trade-off effect between water permeability and Mg 2+ /Li + separation selectivity poses a challenge in the application of these membranes. In this work, rigid-flexible interpenetration and competitive diffusion reaction strategies were proposed to regulate the pore structure and charge density of the functional layer, thus enhancing the overall separation performance of nanofiltration membrane. Phenylbiguanide (PBG) possessing rigid structure, high positive charge density, and low energy transfer barrier was embedded into flexible polyethyleneimine-based polyamide network. This integration facilitated the formation of continuous and semi-permanent microcavities with rigid-flexible coupled structure, and meanwhile, elevated the density of positive charges. Consequently, the modification extended the water molecular transport channels within the functional layer, leading to a notable enhancement in pure water flux, from 7.40 to 26.43 L m −2 h −1 . In addition, due to the faster diffusion of PBG than polyethyleneimine with high molecular weight (70000 Da, as aqueous monomer in this work), it could react with excess 1,3,5-trimesoyl chloride (TMC) on the surface of initial membrane to form a new polyamide layer, which repaired the defects in the functional layer and also enhanced the charge density inside pore channels. Therefore, Mg 2+ /Li + separation selectivity factor increased from 3.79 of TFC membrane to 22.98 of PBG membrane, i.e., by about 6 times. This study provided an effective strategy to develop nanofiltration membranes with both good water permeability and Mg 2+ /Li + selectivity.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
Bio-Design and Manufacturing
·
2021
·Vol. 4
·期 4
·902-911
·
IF 6.302
Zeng Zhiyong,Jiang Guohua,Liu Tianqi,Song Gao,Sun Yanfang,Zhang Xueya,Jing Yanting,Feng Mingjia,Shi Yufei
Abstract Injection therapy for diabetes has poor patient compliance, and the pain occurring at the site of subcutaneous injections causes significant inconvenience to diabetic patients. In this work, to demonstrate the benefits of an alternative drug delivery technique that overcomes these issues, methacrylated gelatin hydrogel-forming microneedles integrated with metformin were developed to adjust blood glucose levels in diabetic rats. Gelatin methacryloyl microneedles (GelMA-MNs) with different degrees of substitution were successfully prepared by a micro-molding method. The resultant GelMA-MNs exhibited excellent mechanical properties and moisture resistance. Metformin, an anti-diabetic drug, was further encapsulated into the GelMA-MNs, and its release rate could be controlled by the three-dimensional cross-linked network of microneedles, thereby exhibiting sustained drug release behaviors in vitro and implying a better therapeutic effect compared with that of subcutaneous injection in diabetic rats. The drug release period could be significantly prolonged by improving the cross-link density of GelMA-MNs. The results of hypoglycemic effect evaluation show that the application of GelMA-MNs for transdermal delivery in diabetic rats has promising benefits for diabetes treatment.
Graphic abstract
研究领域:
生物医学工程
·
药物递送
·
糖尿病治疗
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DOI
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 15
·8799-8812
·
IF 4.21
Sun Lijian,Yang Shuaishuai,Qian Xueren,An Xianhui
Abstract Herein, we introduce antimicrobial activity to cellulose fibers (CFs) by presenting a double “click chemistry” strategy. CFs chemically modified with azide functions are designed as a versatile ligation platform for Cu(I)-catalyzed azide-alkyne click reaction. Glycidyl propargyl ether (GPE) with epoxy groups was grafted onto azidated cellulose fibers (CFs-N 3 ) via azide-alkyne click reaction yielding epoxy cellulose fibers (CFs-Epoxy). Then poly(hexamethylene guanidine) (PHMG) can be chemically grafted onto the CFs to form antibacterial materials (CFs-PHMG) through amino groups initiated epoxy ring-opening click reaction. The results revealed that PHMG was anchored successfully onto CFs via chemical bond formation without significant damage to the morphology of CFs and mechanical performance of cellulose paper. In the antibacterial tests, the functionalized CFs show superior antibacterial activity against E. coli and S. aureus . Importantly, CFs-PHMG paper sheet presented long-term antibacterial effectiveness, remaining ~ 99% antibacterial activity after two months storage in the air environment. This antibacterial CFs-PHMG has good potential application in bioactive paper packaging and medical paper products. Graphic abstract
研究领域:
材料科学
·
生物学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2024
·
IF 5.4
Xian Guo,Borui Zhang,Yutong Chen,Zhi Jia,Xiaoyu Yuan,Li Zhang,Jie Liu,Yanan Liu
Clinical trials based on a single molecular target continue to fail, and the adverse effects of Aβ protein aggregation and neuroinflammation need to be solved and treatment of Alzheimer's disease. Herein, by designed a nano-sized flower mesoporous selenium transport carrier (Met@MSe@Tf) with high enzyme-like activity, metformin (Met) was loaded, and transferrin (Tf) was modified to bind to transferrin receptor to promote receptor-mediated transport across the BBB. In the AD lesion environment, with the acidic environment response dissociation, promote the release of metformin by nanoflower to achieve therapeutic effect in the brain lesion site. Metformin, a major anti-diabetic drug in diabetic metabolism, has been found to be a promising new therapeutic target in neurodegenerative diseases. Further studies showed that the metformin drug release from the designed and synthesized transport nanoparticles showed high intrinsic activity and the ability to degrade the substrate involved, especially the degradation of Aβ deposition in the cortex and hippocampus, increased the phagocytosis of microglia, thus relieving neuroinflammation simultaneously. Collectively, in vivo experiments demonstrated that Met@MSe@Tf significantly increased the number of NeuN-positive neurons in the hippocampus of AD mice, promoted neurovascular normalization in the brain, and improved cognitive dysfunction in AD transgenic AD mice. Thus, it provides a preclinical proof of concept for the construction of a highly modular accurate drug delivery platform for Alzheimer's disease.
研究领域:
药理学
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神经科学
·
生物材料学
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产品关联
DOI
PubMed
高影响因子
Frontiers in Pharmacology
·
2025
·
IF 4.8
Hailiang Li,Zheng Ma,Wanfu Yang,Yifan Zhang,Jinping Sun,Haifeng Jiang,Faxuan Wang,Li Hou,Hechun Xia
Introduction Glioblastoma multiform (GBM) is considered the deadliest brain cancer. Standard therapies are followed by poor patient’s survival outcomes, so novel and more efficacious therapeutic strategies are imperative to tackle this scourge. Metformin has been reported to have anti-cancer effects. However, the precise mechanism underlying these effects remains elusive. A better understanding of its underlying mechanism will inform future experimental designs exploring metformin as a potential adjuvant therapy for GBM. This research aimed to elucidate the potential molecular mechanism of metformin in GBM by integrating proteomics and transcriptomics. Methods The study examined the effects of metformin on GBM cell lines using various methods. The U87, U251 and HA1800 were cultured and modified through PER2 knockdown and overexpression. Cell viability was assessed using the CCK8 assay, and G6PDH activity and intracellular NADPH + levels were measured with specific kits. ROS levels, mitochondrial membrane potential, cell cycle distribution and apoptosis were analyzed by flow cytometry. RNA was extracted for transcriptomic analysis through RNA sequencing, while proteomic analysis was performed on total protein from treated cells. WB detected specific proteins, and RT-qPCR quantified gene expression. In vivo experiments, GBM xenograft on nude mice treated with metformin combining radiotherapy was evaluated and received IHC and TUNEL staining for protein expression and apoptosis assessment. Statistical analyses were conducted using Prism software to identify significant group differences. Results We found that differential expressional genes and proteins relating to circadian rhythm were enriched in proteomic or transcriptomic. The expression of PER2, the key circadian gene, was up-regulated in GBM cell lines when treated with metformin. Furthermore, the expression of silent information regulator 2(SIRT2) was down-regulated, while the expression of the G6PD protein just slightly increased in GBM cell lines. Meanwhile, NADPH+ production and G6PDH enzyme activity significantly decreased. Further study validated that metformin inhibited the cell growth of GBM cell lines through up-regulating PER2 and inhibited SIRT2/G6PD signaling pathway, enhancing radiotherapy(RT) sensitivity. We also found that the inhibition of SIRT2 caused by metformin is mediated by PER2. Discussion We found the pivotal role of metformin as an effective circadian rhythm regulator. Targeting circadian clock gene to modify and rescue the dysfunctional circadian clock of GBM cells at molecular level might be an innovative way to administer cancer chronotherapy and maintain metabolic homeostasis in real world practice.
研究领域:
肿瘤学
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分子生物学
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药理学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）