APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2014
·Vol. 172
·期 6
·3287-3296
·
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
MOLECULES
·
2016
·Vol. 22
·期 1
·12
·
IF 2.465
Ping Li,Yangyang Gao,Zijia Sun,Dan Chang,Ge Gao,Alideertu Dong
In response to the wide spread of microbial contamination induced by bacterial pathogens, the development of novel materials with excellent antibacterial activity is of great interest. In this study, novel antibacterial chitosan (CS) and polyhexamethylene guanidine hydrochloride (PHGC) dual-polymer-functionalized graphene oxide (GO) (GO-CS-PHGC) composites were designed and easily fabricated. The as-prepared materials were characterized by Fourier transform infrared (FTIR), X-ray photoelectron spectrometer (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and Raman spectroscopy. Their antibacterial capability towards bacterial strains was also studied by incubating both Gram-negative bacteria and Gram-positive bacteria in their presence. More significantly, the synergistic antibacterial action of the three components was assayed, and the findings implied that the as-prepared GO-CS-PHGC shows enhanced antibacterial activity when compared to its single components (GO, CS, PHGC or CS-PHGC) and the mixture of individual components. Not only Gram-negative bacteria but also Gram-positive bacteria are greatly inhibited by GO-CS-PHGC composites. The minimum inhibitory concentration (MIC) value of GO-CS-PHGC againstE. coliwas 32 μg/mL. With the powerful antibacterial activity as well as its low cost and facile preparation, GO-CS-PHGC has potential applications as a novel antibacterial agent in a wide range of biomedical uses.Keywords:graphene oxide;chitosan;polyhexamethylene guanidine hydrochloride;antibacterial activity
研究领域:
材料科学
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生物学
·
医学
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DOI
PubMed
高影响因子
Soft Matter
·
2021
·Vol. 17
·期 17
·4604-4614
·
IF 3.679
Meihua Gao,Na Du,Zhiyin Yao,Ying Li,Nan Chen,Wanguo Hou
Monoalkyl phosphates (MAPs) are one kind of important single-chain weak acid/salt type surfactants, but the understanding of their aggregation behavior in water is very limited due to their insolubility at room temperature. In the current work, the effect of guanidinium salts (GuSalts) on the solubility of sodium monododecylphosphate (SDP), a typical MAP, in water was determined at 25.0 °C, and the aggregation behavior of SDP in the GuSalt/water mixtures was investigated. The solubility of SDP is significantly improved by GuSalts including GuCl, GuSO4, GuSO3, GuPO4, and GuCO3 at 25.0 °C, resulting in an isotropic phase. SDP vesicles are spontaneously formed in the isotropic phase, with a critical vesicle concentration of ∼1.0 mM independent of the type of GuSalts. A “bridging dimer” mechanism is proposed to explain the formation of SDP vesicles. The SDP vesicles have a unilamellar structure with a size of ∼80 nm and an alkyl interdigitated degree of ∼25%, and exhibit size-selective permeability. Interestingly, a temperature-induced reversible transition between vesicles and α-gels was observed for the SDP/GuSalt/H2O systems when the SDP content is higher than 20 mM. The α-gels obtained are composed of vesicles and bilayer sheets, showing similar viscoelasticity to conventional gels, although their water content is as high as ∼98 wt%. The microviscosity of SDP vesicle membranes (ca. 35.79–49.34 mPa s at 25.0 °C) and the transition temperature between vesicles and α-gels (ca. 21.0–22.8 °C) are all dependent of the type of GuSalts. This work deepens the understanding of the aggregation behavior of MAPs and also provides valuable information for their practical applications.
研究领域:
生物化学
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软物质科学
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材料科学
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DOI
PubMed
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 8
·1847-1856
·
IF 2.578
Saijun Ye,Dafu Wei,Xiang Xu,Yong Guan,Anna Zheng
Antimicrobial polyamide (PA) received much attention for the demand of packaging and biomedical fields. In this paper, an antimicrobial PA6 membrane was prepared via a surface chemical reaction. A highly effective antibacterial component (PHMG-E) with terminal epoxy group was firstly synthesized via a reaction between polyhexamethylene guanidine hydrochloride (PHMG) and ethylene glycol diglycidyl ether (EGDE). Then, PHMG-E was bonded on the surface of PA6 membrane with secondary amine reduced by borane-tetrahydrofuran (BH 3 -THF). The antimicrobial rates of surface-modified PA6 membrane (PA6-PHMG) against Escherichia coli and Staphylococcus aureus were both higher than 99.99%, and the PHMG was non-leaching due to the chemical bonding. The hydrophilicity of antibacterial PA6 membrane was also significantly improved and the mechanical performance became better.
研究领域:
材料科学
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生物医学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 33
·15642-15664
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IF 3.5
Du Zhanjie,Wang Ru,Liu Bin,Zheng Tao,Dong Yanwei,Chen Xuhua,Liu Zeyu,Han Shengxing,Zeng Yao,Li Yiken
Through Silicon Via (TSV), a kind of 3D packaging technique, can improve chip integration based on “More than Moore” scheme. The larger copper area ratio at the TSV barrier layer interface requires strong adjustability of the removal rate selection ratio of copper, tantalum and TEOS–SiO 2 , and stronger surface defect control and surface profile correction capabilities. In this paper, the effects of guanidine hydrochloride (GH) and 2,2′-[[(Methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol (TT-LYK) system on the tunability of Ta and Cu removal rate in chemical mechanical polishing (CMP) of TSV wafer barrier material were studied. GH can complex \({\text{TaO}}_{4}^{{3}-}\) , while TT-LYK can form a protective film on the surface of Cu, thereby achieving rate regulation. The results showed that when the concentration of GH increased from 0 to 2 wt%, the removal rate selectivity ratio of Ta and Cu raised from 1.02:1 to 1.26:1. When the concentration of TT-LYK increased from 2.5 to 10 mmol/L, the removal rate selectivity ratio of Ta and Cu increased from 1.33:1 to 1.79:1, which verified that the GH and TT-LYK systems can efficiently regulate the rate and rate selection ratio of Ta and Cu. Surface roughness for both metals decreased from pre-polishing values of 5.03 nm to post-polishing values of 0.37 nm for Ta, from pre-polishing values of 5.33 nm to post-polishing values of 1.26 nm for Cu indicating that GH and TT-LYK systems significantly improved the surface quality. Graphical abstract
研究领域:
材料科学
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半导体制造
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化学工程
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DOI
高影响因子
BIOMACROMOLECULES
·
2022
·
IF 6.978
Yu Rao,Jinghong Wang,Huanhuan Wang,Hong Wang,Rong Gu,Jie Shen,Qing Hao,John L. Brash,Hong Chen
The emergence of “superbugs” is not only problematic and potentially lethal for infected subjects but also poses serious challenges for the healthcare system. Although existing antibacterial agents have been effective in some cases, the side effects and biocompatibility generally present difficulties. The development of new antibacterial agents is therefore urgently required. In this work, we have adapted a strategy for the improvement of poly(hexamethylene guanidine) hydrochloride (PHMG), a common antibacterial agent. This involves copolymerization of separate monomer units in varying ratios to find the optimum ratio of the hydrocarbon to guanidine units for antibacterial activity. A series of these copolymers, designated as PGB, was synthesized. By varying the guanidine/hydrophobic ratio and the copolymer molecular weight, a structure-optimized PGB was identified that showed broad-spectrum antibacterial activity and excellent biocompatibility in solution. In an antibacterial assay, the copolymer with the optimum composition (hydrophobic unit content 25%) inhibited >99% Staphylococcus aureus and was compatible with mammalian cells. A polyurethane emulsion containing this PGB component formed transparent, flexible films (PGB-PU films) on a wide range of substrate surfaces, including soft polymers and metals. The PGB-PU films showed excellent bacteriostatic efficiency against nosocomial drug-resistant bacteria, such as Pseudomonas aeruginosa and methicillin-resistant S. aureus (MRSA). It is concluded that our PGB polymers can be used as bacteriostatic agents generally and in particular for the design of antibacterial surfaces in medical devices.
研究领域:
生物材料
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医学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
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2021
·
IF 4.952
Yingying Zhang,Lan Yang,Qingfeng Dong,Li Li
Poly(hexamethylene biguanide) hydrochloride (PHMB) loaded poly(vinyl alcohol) (PVA) fibrous films were produced via electrospinning as active food packaging material. Fourier transform infrared spectroscopy analysis confirmed that PHMB has been incorporated into the PVA fibers and scanning electron microscopy analysis indicated that the fibrous films were successfully prepared. The thermal stability and antibacterial activity of PVA/PHMB fibrous films were tested. The application of fibrous films on the preservation of Japanese sea bass ( Lateolabrax japonicus ) during cold storage at 4 °C was investigated. Compared with the control sample, PHMB loaded PVA fibrous films effectively lowered the total viable count, inhibited Pseudomonas spp. and H 2 S-producing bacteria, as well as delayed the production of total volatile basic nitrogen. The results revealed that PVA/PHMB fibrous films had a positive effect on maintaining quality and extending the shelf life of sea bass.
研究领域:
食品科学
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材料科学
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DOI
高影响因子
ACS Applied Energy Materials
·
2025
·
IF 5.5
Huxue He,Yong Zhu,Xiong Chang,Kunpeng Li,Mengni Zhou,Duo Xu,Fashe Li,Xing Zhu,Hua Wang,Jiangzhao Chen,Tao Zhu
The high defect density in perovskite materials poses a significant challenge to improving the efficiency and long-term stability of perovskite solar cells (PSCs). To address this, molecules featuring electron-donating or electron-withdrawing groups have been utilized for defect passivation. In this study, biguanide hydrochloride (BH), a multifunctional organic molecule, was introduced into the perovskite layer. The nitrogen groups in BH establish strong chemical interactions with Pb2+ ions, altering the perovskite’s crystallization direction, significantly reducing defect state density, suppressing nonradiative recombination, enhancing carrier separation efficiency, and promoting carrier transport. PSCs incorporating BH achieved a notable power conversion efficiency (PCE) of 23.51%, with a short-circuit current density (JSC) of 24.85 mA cm–2 and an open-circuit voltage (VOC) of 1.13 V. Following 1500 h of aging under 35% relative humidity, BH-modified PSCs demonstrated exceptional environmental stability, retaining 95.1% of their initial PCE, significantly outperforming control devices. This study presents an innovative approach by exploiting the strong chelating ability of biguanide hydrochloride (BH) to expand the application of guanidine derivatives in perovskite photovoltaics. The proposed strategy not only enhances device performance (PCE) but also ensures long-term operational durability, paving the way for next-generation stable and efficient perovskite solar cells.
研究领域:
材料科学
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能源科学
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化学工程
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产品关联
DOI
高影响因子
Frontiers of Materials Science
·
2022
·Vol. 16
·期 2
·1-15
·
IF 2.612
Xiao Chuang,Zhang Ge,Liang Wencheng,Wang Zhaochuang,Lu Qiaohui,Shi Weibin,Zhou Yan,Guan Yong,Lang Meidong
Managing wounds is a growing universal problem and developing effective wound dressings to staunch bleeding and protect wounds from bacterial infections is an increasingly serious challenge. In this work, a remolding electrospinning nanofiber three-dimensional structure wound dressing (CCP) was prepared with superhydrophilicity, high water absorption and absorbing capacity, excellent hemostatic capacity and antibacterial ability, and biocompatibility to promote wound healing. Polyhexamethylene guanidine hydrochloride (PHMG) was grafted to cellulose diacetate (CDA) wound dressing surface through an amide reaction. A water contact angle analysis demonstrated that CCP wound dressing could be beneficial to promote wound exudate management effectively with rapid absorption of water within 0.2 s. In vitro hemo- and cytocompatibility assay showed that a CCP wound dressing had no significant hemotoxicity or cytoxicity. Specifically, CCP wound dressings could be beneficial to accelerate wound hemostasis and further reduce mortality caused by uncontrolled bleeding. Furthermore, CCP wound dressings have an excellent antibacterial ability, which could be beneficial to inhibit wound inflammatory over-reaction and promote normal wound healing. Combined together, the prepared wound dressing in this research effort is expected to have high-potential in clinical applications.
研究领域:
生物材料学
·
医学工程
✓ 已验证
DOI
高影响因子
Materials Futures
·
2025
·
IF 10.8
Jiajia Du,Yilin Chang,Le Liu,Zhibin Yu,Qinglin Du,Wenfeng Yang,Yuan Qiu,Fushen Lu,Tonggang Jiu,Huanqi Cao
The disordered crystal growth and undesired degradation of perovskite films limit the further improvement of perovskite solar cells (PSCs) performance and their commercialization. Herein, an in situ modulation strategy is proposed for preparing high-quality and stable perovskite film through adjustment of phase transformation kinetics. Benefiting from the in situ reaction between chloroformamidinium hydrochloride (ClFACl) and FA cations, the impurity intermediate phase in the perovskite film is inhibited and the α-FAPbI3 phase is induced to grow along a preferred (001) orientation. Furthermore, the introduction of ClFACl and in situ formation of guanidinium salts (FA-Gua) strengthen the intermolecular interactions in the interior of crystals, which restrains the α-phase degradation of the as-prepared perovskite films under humid and thermal treatments. With crystal orientation optimization and defects reduction, the PSCs with in situ formed FA-Gua yield a champion efficiency of 25.85% and demonstrate excellent phase stability under long-term thermal and humid ageing conditions. This in situ chemical modulation strategy expands the avenue toward optimization of crystallization orientation and α-phase stabilization, promoting the development of PSCs with enhanced performance and stability.
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 17
·50290
·
IF 2.52
Yuxing Liu,Yalu Zou,Jing Wang,Shuo Wang,Xiaofei Liu
This study reported the synthesis and properties of a new cationic waterborne polyurethane coating. In this work, a chitosan derivative, chitosan biguanide hydrochloride (CSGH), was synthesized, which was used as a blocking agent and cross-linking agent to participate in the copolymerization of waterborne polyurethane (WPU) and a bioactive ingredient to enhance the biocompatibility of the coating. FTIR results demonstrated the reaction of CSGH with WPU. Moreover, the particle size distribution of the emulsion and SEM results showed that CSGH and WPU were well integrated. Benefiting from the formation of the cross-linking network, the thermodynamic properties of the coating were significantly improved. Furthermore, due to adding 3 wt% CSGH, the water contact angle of the coating surface decreased from 97.01° to 69.30°, indicating that the coating surface changed from hydrophobic to hydrophilic. And a specific resistance to Staphylococcus aureus and Escherichia coli was exhibited without cytotoxicity, the resistance rates could reach 85% and 91% respectively. It is highlighted that this WPU-CSGH coating has great application potential in the field of medical interventional catheters.
研究领域:
材料科学
·
高分子化学
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生物医学工程
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医疗器械
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Baifeng Wu,Xiaofeng Wang,Xuefeng Xia,Qixin Wan,Yangsheng Li,Fan Li
The power conversion efficiency (PCE) of the perovskite solar cell (PSC) has made an illustrious breakthrough in the past ten years. However, it is still a great challenge to fabricate high-quality perovskite films due to the intrinsic high defect-density and internal non-radiative recombination, which has severely hindered the development of PSCs . Herein, a new-type additive guanidinium tetrafluoroborate (GuaBF 4 ) is introduced to improve the perovskite films quality, thus boosting photovoltaic performance of resultant PSCs . It is demonstrated that owing to the synergistic effect of Gua + and BF 4 − , the introduction of GuaBF 4 can improve the quality of CH 3 NH 3 PbI 3 (MAPbI 3 ) films. Through optimizing the concentration of GuaBF 4 , the MAPbI 3 film with GuaBF 4 displays higher crystallinity , enlarged crystal grain and smoother surface. Furthermore, by virtue of the strong interaction between MAPbI 3 and GuaBF 4 , the inclusion of GuaBF 4 can effectively passivate traps/defects in perovskite films, thereby diminishing the non-radiative recombination and promoting the charge carrier transportation. Consequently, a high-performance MAPbI 3 PSC with a PCE of 20.62 %, lessened hysteresis behavior and improved moisture stability is achieved. Our research emphasizes on the significance of the synergistic effect in additives for high-performance PSCs.
研究领域:
材料科学
·
能源科学
·
半导体器件
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表面化学
·
光电子学
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DOI
高影响因子
危险品化学品经营许可证（带存储）