Polymer Chemistry
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2013
·Vol. 4
·期 6
·1921-1931
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IF 5.231
Wei Zhou,Weijun Yu,Zesheng An
Core cross-linked star (CCS) polymers of poly(N,N-dimethylacrylamide) (PDMA) were prepared and explored as macromolecular chain transfer agents (Macro-CTAs) in the emulsion polymerization of styrene. The mass ratio of styrene : CCS and the solid content were systematically varied to elucidate their effect on the size and morphology of the particles. Control experiments using linear PDMA as a Macro-CTA were also performed in order to understand the mechanistic difference in CCS-mediated emulsion polymerization. While a two-phase process was typical of emulsion polymerization using linear Macro-CTAs, the CCS polymers functioned as “seeds” for the emulsion polymerization of styrene and exhibited a much higher polymerization rate. Significant clustering of spherical particles was observed when the mass ratio of styrene : CCS was increased while maintaining the solid content. On the other hand, linear and branched fibers were observed when the solid content was increased while maintaining the mass ratio of styrene : CCS. This morphology transformation is unique to CCS-mediated emulsion polymerization, and a protrusion mechanism caused by the cross-links in the core of the CCS was proposed to account for the aggregation of spherical particles into clusters or fibers.
研究领域:
材料科学
·
高分子化学
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高影响因子
Polymer Chemistry
·
2013
·Vol. 4
·期 6
·1950-1959
·
IF 5.231
Xiaofang Shi,Miao Miao,Zesheng An
Homoarm and heteroarm core cross-linked star (CCS) polymers based on poly(N,N-dimethylacrylamide) (PDMA) as the high-polarity arm and poly(2-methoxyethylacrylate) (PMEA) as the low-polarity arm were efficiently prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization in a dispersion polymerization system. PDMA and PMEA arm polymers exhibited similar conversion rates, such that their composition in the heteroarm CCS polymers was easily controlled by the feed ratio in the synthesis. The ability to control the arm composition allowed facile tuning of the polarity of the CCS polymers. Heteroarm CCS polymers self-assembled in water to form aggregates and their size was related to the composition and polarity of the CCS polymers. The composition and polarity of the CCS polymers significantly affected the emulsifying behaviour of the CCS polymers as emulsifiers. Oil-in-water (o/w) emulsions were favoured for CCS polymers with relatively high polarity and lowering the polarity of CCS polymers to a certain degree enhanced the stability of the emulsions. Multiple emulsions, both o/w and water-in-oil (w/o), were gradually produced when the polarity of CCS polymers was gradually lowered and the oil fraction in the emulsion samples was gradually increased, and at the same time the emulsions also became increasingly less stable.
研究领域:
聚合物科学
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材料化学
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胶体科学
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纳米技术
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高影响因子
JOURNAL OF NEUROSCIENCE
·
2026
·
IF 4.3
Xiaoli Su,Xingli Tan,Ying Wang,Weiwei Liang,Di Wang,Di Huo,Hongyong Wang,Yan Qi,Wenmo Zhang,Ling Han,Dongmei Zhang,Ming Wang,Jing Xu,Shuyu Wang,Jing Wang,Honglin Feng
Mutations in superoxide dismutase 1 (SOD1) compromise its metal-binding capacity, resulting in protein misfolding and aggregation, which ultimately induces cellular apoptosis in amyotrophic lateral sclerosis (ALS). Copper metabolism domain containing 1 (COMMD1), a gene implicated in copper homeostasis, has not been thoroughly characterized in the context of ALS pathogenesis. In this study, we identified elevated COMMD1 expression in ALS, potentially contributing to diminished copper incorporation into SOD1. Knockdown of COMMD1 enhanced palmitoylation of the copper chaperone for SOD1 (CCS), facilitating its membrane translocation and promoting copper loading into SOD1, thereby conferring neuroprotection in ALS. Mechanistically, we established that COMMD1 knockdown augments CCS palmitoylation via activation of the hypoxia inducible factor 1 subunit alpha (HIF-1α)/fatty acid synthase (FASN) signaling axis. In vivo investigations utilizing male hSOD1G93A transgenic mice demonstrated that COMMD1 deficiency markedly ameliorated the deterioration of motor function and prolonged survival duration. These findings collectively suggest that COMMD1 represents a potential therapeutic target for ALS intervention.Significance Statement Superoxide dismutase 1 (SOD1) was the first identified mutant gene associated with amyotrophic lateral sclerosis (ALS). Mutations in SOD1 compromise its metal-binding function, resulting in neuronal apoptosis, a hallmark of ALS pathogenesis. Utilizing the SOD1G93A models of ALS, our findings revealed that COMMD1 deficiency significantly elevates copper incorporation into SOD1, consequently attenuating cellular apoptosis. These results suggest that targeted inhibition of COMMD1 could represent a potential therapeutic strategy for ALS treatment.
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PubMed
高影响因子
Polymer Chemistry
·
2013
·Vol. 4
·期 15
·4092-4102
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IF 5.231
Qijing Chen,Xueteng Cao,Hao Liu,Wei Zhou,Lianjie Qin,Zesheng An
Well-defined core cross-linked star (CCS) polymers of poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) were prepared via cross-linking copolymerization in an aqueous-based dispersion polymerization system, mediated by reversible addition–fragmentation chain transfer (RAFT) polymerization. The synthesized CCS polymers were characterized by nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), dynamic light scattering (DLS), and conductivity and zeta potential measurements. The use of PDMAEMA CCS polymers as effective emulsifiers for oil-in-water emulsions was investigated. Interfacial tension measurements showed that the CCS polymer reduced the interfacial tension between water and oil in a pH-dependent manner. Gelled high internal phase emulsions (HIPEs) were formed at high oil fractions (80–89 vol%) and over a wide range of pH values (2–12). The HIPEs were characterized by conductivity, confocal laser scanning microscopy (CLSM) and rheology. The emulsion properties in terms of oil droplet size, long-term stability and rheology were pH-dependent. Complete demulsification of HIPEs was easily realized 2 min after the addition of base. The CCS-stabilized HIPEs were used as templates to prepare porous hydrophilic polymers by polymerizing the monomers in the continuous aqueous phase. The study presented herein reveals that responsive CCS polymers can be used as effective stabilizers for the formation of responsive HIPEs, which have a wide range of applications.
研究领域:
材料科学
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化学工程
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界面化学
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高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-8
·
IF 4.259
Chen Qijing,Shi Ting,Han Fei,Li Zihan,Lin Chao,Zhao Peng
A hydrophobic CCS polymer of poly(benzyl methacrylate) (PBzMA) was prepared in toluene by reversible addition-fragmentation chain transfer (RAFT)-mediated dispersion polymerization. The CCS polymer, with poly(benzyl methacrylate) as the arm and crosslinked N , N ′-bis(acryloyl)cystamine (BAC) as the core, was confirmed by characterization with gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. Three kinds of oils (toluene, anisole and styrene) were chosen to study the emulsification properties of PBzMA CCS polymer. The oils can be emulsified by CCS polymer to form water-in-oil (w/o) emulsions. Moreover, w/o high internal phase emulsions (HIPEs) can be obtained with the increase of toluene and styrene volume fractions from 75% to 80%. Porous polystyrene monolith and microparticles were prepared from the emulsion templates and characterized by the scanning electronic microscopy (SEM). With the internal phase volume fraction increased, open-pore porous monolith was obtained.
研究领域:
材料科学
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化学工程
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PubMed
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 37
·25930-25938
·
IF 3.9
Qiaolin Du,Jian Sun,Yanyan Zhou,Yadong Yu,Weijing Kong,Chaoqun Chen,Yifeng Zhou,Ke Zhao,Changyu Shao,Xinhua Gu
The barrier membranes of guided bone regeneration (GBR) have been widely used in clinical medicine to repair bone defects. However, the unmatched mechanical strength, unsuitable degradation rates, and insufficient regeneration potential limit the application of the current barrier membranes. Here, amorphous calcium phosphate–carboxylated chitosan–polyvinyl alcohol (ACP–CCS–PVA) composite membranes are fabricated by freeze–thaw cycles, in which the ATP-stabilized ACP nanoparticles are uniformly distributed throughout the membranes. The mechanical performance and osteogenic properties are significantly improved by the ACP incorporated into the CCS–PVA system, but excess ACP would suppress cell proliferation and osteogenic differentiation. Our work highlights the pivotal role of ACP in GBR and provides insight into the need for biomaterial fabrication to balance mechanical strength and mineral content.
研究领域:
生物材料学
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组织工程学
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PubMed
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 14
·4277-4284
·
IF 5.368
Xueteng Cao,Chunlei Zhang,Songbai Wu,Zesheng An
We have developed a highly efficient, one-step approach for the synthesis of core cross-linked star (CCS) polymers using commercial macromonomers (polyethylene glycol methyl ether methacrylates) as the arms via RAFT-mediated emulsion polymerization in aqueous media. This approach employs a small molecular chain transfer agent (CTA), commercial macromonomer, hydrophobic cross-linker, and optional hydrophobic spacing monomer as the polymerization recipe to synthesize CCS polymers via direct one-step polymerization in aqueous buffer solution. Various polymerization parameters, including buffer concentration and molar ratio of macromonomer/cross-linker/spacing monomer relative to CTA, were investigated. CCS polymers of high yield and low dispersity were obtained within 4 h under a wide range of conditions. Analysis of polymerization kinetics and macromolecular parameters of the generated polymeric species during the polymerization process led to insights into the mechanistic aspects of the CCS formation process, which was proposed to involve three stages, i.e., polymer chain growth, cross-linking to form CCS, and CCS growth. Finally, synthesis of CCS polymers using macromonomers of different molecular weights pointed to the necessity for optimization of the polymerization conditions for each macromonomer, possibly due to different polymerization rates and steric hindrance.
研究领域:
高分子化学
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材料科学
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高影响因子
Polymer Chemistry
·
2013
·Vol. 5
·期 1
·175-185
·
IF 5.231
Qijing Chen,Yuanyuan Xu,Xueteng Cao,Lianjie Qin,Zesheng An
A series of five core cross-linked star (CCS) polymers has been synthesized by RAFT-mediated heterogeneous polymerization in aqueous media. These CCS polymers consist of poly(MEAx-co-PEGAy) (MEA is 2-methoxyethyl acrylate and PEGA is poly(ethylene glycol) acrylate) of different compositions. They exhibit responsiveness to both temperature and salt. Addition of kosmotropes reduces the cloud point, and addition of chaotropes raises the cloud point. These CCS polymers can stabilize dodecane-in-water high internal phase emulsions (HIPEs) in the absence or presence of salts. Addition of salts has negligible effect on the maximum oil fraction, the size of oil droplets or the stability of the HIPEs. HIPEs with large oil fractions (up to 92 vol%) at low concentrations of CCS polymers (≤1 wt%) can be routinely obtained. When the oil volume fraction is larger than 74 vol%, gelled HIPEs are formed with long-term stabilities (more than three months). The temperature and salt responsiveness of the CCS polymers is transferred to the CCS-stabilized HIPEs. Addition of kosmotropes can enhance demulsification efficiency, while addition of chaotropes can decrease demulsification efficiency or enhance the thermal stability of the CCS-stabilized HIPEs. The emulsification–demulsification cycle can be successfully repeated four times. The facile and aqueous synthesis of CCS polymers and the fast response of the CCS-stabilized HIPEs will open up new opportunities for the preparation and exploitation of a range of smart soft materials.
研究领域:
材料科学
·
化学工程
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高影响因子
MOLECULAR AND CELLULAR ENDOCRINOLOGY
·
2026
·
IF 3.4
Yanbing Lou,Tingting Yang,Chenglong Xia,Shijun Yang,Huidan Deng,Yanqiu Zhu,Jing Fang,Zhicai Zuo,Hongrui Guo
CCS and ATOX1 is a specific target of copper in hormone secretion of ovarian granulosa cells. • MEK1-ERK1/2 pathway is involved in copper-affected hormone secretion. • Copper affects hormones secretion through CCS and ATOX1 dependent MEK1-ERK1/2 pathway. Steroid hormone synthesis in granulosa cells (GCs) is crucial for normal follicular development and ovulation. Emerging evidence suggests that copper (Cu), a trace element, influences hormone secretion in yak granulosa cells (YGCs); however, the underlying mechanisms remain unclear. In this study, we demonstrated that Cu supplementation upregulates estradiol (E2) and progesterone (P4) secretion in YGCs through the activation of the MEK1-ERK1/2 signaling pathway. Our findings indicate that the Cu chaperones ATOX1 and CCS, but not the Cu-dependent enzyme LOX, are essential for Cu-induced MEK1-ERK1/2 activation and subsequent hormone secretion. Gene silencing of ATOX1 or CCS resulted in reduced MEK1-ERK1/2 phosphorylation and steroidogenesis, highlighting their regulatory roles in this pathway. Although LOX influenced hormone secretion, it did not affect MEK-ERK phosphorylation, suggesting a MEK-independent mechanism. These findings reveal that Cu regulates steroid hormone synthesis in YGCs via a CCS- and ATOX1-dependent MEK1–ERK1/2 pathway, providing new insights into the molecular basis of Cu-associated reproductive disorders in yaks. Download: Download high-res image (289KB) Download: Download full-size image
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高影响因子
Environmental Science-Nano
·
2026
·
IF 5.1
Hong Yang,Peng Zhao,Xiaolei Wei,Chao Huang,Wu-Hong Lv,Yu-Chen Zhou,Zhi Luo
Copper oxide nanoparticles (CuO NPs) are widely used in industry and agriculture, leading to their persistent occurrence and accumulation in aquatic environments and posing potential environmental risks. However, the specific role and underlying mechanisms of CuO NPs on the health risks of aquatic organisms remain unclear. This study revealed that dietary exposure to high levels of CuO NPs elevated hepatic Cu content, induced oxidative stress and mitochondrial dysfunction that exacerbate hepatic lipotoxicity. Mechanistically, high dietary CuO NPs enhanced the interaction between domains 1 and 3 of the Cu chaperone for superoxide dismutase (Ccs) and mitogen-activated protein kinase kinase 1 (Mek1), which subsequently activated the phosphorylation of extracellular signal-regulated protein kinase 1/2 (Erk1T202/Y204 and Erk2T185/Y187). The activated Erk1/2 mediated CuO NPs-induced lipotoxicity by suppressing the expression of peroxisome proliferator-activated receptor α (Pparα) and promoting its phosphorylation at the S77 site. Further investigation demonstrated that Pparα phosphorylation impaired fatty acid β-oxidation by downregulating the promoter activities of long chain acyl-coA dehydrogenase (acadl) and carnitine palmitoyl transferase Ia1b (cptIa1b). For the first time, this study elucidated the novel mechanism by which CuO NPs induced metabolic disorder via the Ccs/Mek1/Erk1/2/Pparα signaling axis. These findings provide critical evidence for the toxicological and environmental risk assessment of nanoparticles, while also deepen the mechanistic understanding of nanometal exposure-induced health effects in aquatic animals within complex environments.
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高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2022
·
IF 5.999
Ruigeng Yang,Yueru Wei,Mengyang Zhao,Mengxiao Shi,Yongxing Zhao,Pengchao Sun
The abuse of antibiotics has led to the emergence of multidrug-resistant bacterial strains worldwide, which greatly threatens human health. In the present work, we developed single-atom catalysts (SACs) with atomically dispersed Fe as catalytic sites (Fe-SACs) to combat multidrug-resistant bacteria by elevating cellular reactive oxygen species (ROS). Our intensive studies confirmed that Fe-SACs were successfully prepared and exhibited excellent catalase (CAT)-, oxidase (OXD)-, and peroxidase (POD)-like activities. To enhance water dispersibility, biosafety and the interactions between the nanodrugs and gram-positive bacteria, phenylboronic acid group-functionalized carboxylated chitosan (CCS-PBA) was coated on the surface of Fe-SACs to yield [email protected] for in vitro and in vivo studies. The synergistic catalytic activity and photothermal activity of [email protected] effectively overcame multidrug-resistant bacterial strains ( MRSA) in vitro and significantly accelerated wound healing in vivo , suggesting the great potential of SACs to overcome infectious disease caused by multidrug-resistant bacteria.
研究领域:
纳米技术
·
细菌学
·
材料科学
·
生物医学工程
·
药学
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PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Jia-ping Ke,Jia-Yi Li,Zi Yang,Hao-Yue Wu,Jing-Ya Yu,Yi Yang,Chen-Hui Chen,Peng Zhou,Fang Hua,Wei Wang,Fenglin Hu,Gang-Xiu Chu,Xiao-Chun Wan,Guan-Hu Bao
Tea drinking impacts aging and aging-related diseases. However, knowledge of anti-aging molecules other than the major catechins in complex tea extracts remains limited. Here we used Caenorhabditis elegans to analyze the longevity effects of tea extracts and constituents comprehensively. We found that the hot water extract of green tea prolonged lifespan and heathspan. Further, the MeOH fraction prolonged lifespan significantly longer than other fractions. Correlation analysis between mass spectroscopic data and anti-aging activity suggests that ester-type catechins (ETCs) are the major anti-aging components, including 4 common ETCs, 6 phenylpropanoid-substituted ester-type catechins (PSECs), 5 cinnamoylated catechins (CCs), 7 ester-type flavoalkaloids (ETFs), and 4 cinnamoylated flavoalkaloids (CFs). CFs (200 μM) are the strongest anti-aging ETCs (with the longest 73% lifespan extension). Green tea hot water extracts and ETCs improved healthspan by enhancing stress resistance and reducing ROS accumulation. The mechanistic study suggests that they work by multiple pathways. Moreover, ETCs modulated gut microbial homeostasis , increased the content of short-chain fatty acids, and reduced fat content. Altogether, our study provides new evidence for the anti-aging benefits of green tea and insights into a deep understanding of the chemical truth and multi-target mechanism.
研究领域:
衰老研究
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生物化学
·
药理学
·
微生物学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）