ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2024
·
IF 3.8
Wei Yuxin,Bai Qingqing,Ning Xinlu,Bai Xiaofan,Lv Jie,Li Meng
Sensitive and accurate detection of the amyloid-β (Aβ) monomer is of fundamental significance for early diagnosis of Alzheimer’s disease (AD). Herein, inspired by the specific Cu-Aβ monomer coordination, a cutting-edge colorimetric assay based on single-atom Cu anchored N-doped carbon nanospheres (Cu-NCNSs) was developed for Aβ monomer detection and an amyloidogenesis study. By directly pyrolyzing Cu 2+ -incorporated covalent organic frameworks (COFs), the resulting Cu-NCNSs with a high loading of Cu (8.04 wt %) exhibited outstanding peroxidase-like activity. The strong binding affinity of Aβ monomer to Cu-NCNSs effectively inhibited their catalytic activity, providing the basis for the colorimetric assay. The Cu-NCNSs-based sensor showed a detection limit of 1.182 nM for Aβ monomer, surpassing traditional techniques in terms of efficiency, accuracy and simplicity. Moreover, the system was successfully utilized for Aβ monomer detection in rat cerebrospinal fluid (CSF). Notably, the distinct inhibitory effects of monomeric and aggregated Aβ species on the catalytic activity of Cu-NCNSs were allowed for monitoring of the dynamic aggregation process of Aβ. Compared to thioflavin T (ThT), the most widely used amyloid dye, the detection system exhibited greater sensitivity towards toxic Aβ oligomers, which was crucial for early AD diagnosis and treatment. Our work not only sheds light on the rational design of highly active single-atom nanozymes from COFs but also expands the potential applications of nanozymes in early disease diagnosis. Graphical
研究领域:
生物化学
·
医学诊断
·
纳米材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 135
·期 5
·2903-2913
·
IF 2.209
Wang Yujie,Wu Hui,Wang Jiuxia,Lou Pengxiao,Zhao Yang,Bai Guangyue
Thermodynamics of interaction between cationic gemini surfactants [C 12 H 25 (CH 3 ) 2 N(CH 2 ) s N(CH 3 ) 2 C 12 H 25 ]Br 2 , ( s = 2, 6 or 10, assigned as C 12 C s C 12 Br 2 ) and sodium deoxycholate (NaDC) in aqueous solution has been investigated by isothermal titration calorimetry (ITC), fluorescence and turbidity measurements. The critical micelle concentrations for NaDC-rich mixture (cmc mix,12-s-12 ) were determined by fluorescence method. The cmc mix,12-s-12 values are much smaller than those for pure C 12 C s C 12 Br 2 surfactants, and decrease as the spacer length ‘s’ increases. There is a strong synergistic effect between two surfactants in the NaDC-rich region. In the higher C 12 C s C 12 Br 2 concentration range above cmc mix,12-s-12 , we did obtain from ITC and turbidity measurements the critical parameters for different events that occur as the C 12 C s C 12 Br 2 concentration increases, including the critical concentrations ( C P , C R , C M ) of formation and redissolution for LC of the mixed C 12 C s C 12 Br 2 /NaDC systems and transition to gemini-rich micelles. In comparison with the mixed C 12 C s C 12 Br 2 /NaC systems reported with sodium cholate (NaC), the mixed systems with NaDC have lower cmc mix,12-s-12 , C P , C R and C M , and thus different self-aggregation processes are well controlled by surfactant concentration and molar fraction. Importantly, ITC allowed us to directly measure the enthalpy changes corresponding to different self-aggregation processes—redissolution enthalpy (∆ H R ) of LC of mixed surfactants and transition enthalpy (∆ H M ) from LC to gemini-rich micelles. Eventually, we discussed the cross-linking effect on NaDC-rich micelles of the gemini surfactant (C 12 C s C 12 Br 2 ) with double hydrophobic chains and cationic head groups linked through a methylene spacer.
研究领域:
物理化学
·
表面活性剂科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MASS SPECTROMETRY
·
2020
·Vol. 55
·期 10
·e4643
·
IF 1.671
Bo Pang,Xiaoyu Zhuang,Xinyu Bian,Shu Liu,Zhiqiang Liu,Fengrui Song
A wealth of epidemiological evidence indicates a strong link between type 2 diabetes (T2D) and Alzheimer's disease (AD). The fiber deposition with cross-β-sheet structure formed by self-aggregation and misfolding of amyloidogenic peptides is a common hallmark of both diseases. For the patients with T2D, the fibrils are mainly found in the islets of Langerhans that results from the accumulation of human islet amyloid polypeptide (hIAPP). The major component of aggregates located in the brain of AD patients is amyloid-β (Aβ). Many biophysical and physiological properties are shared by hIAPP and Aβ, and both peptides show similar cytotoxic mechanisms. Therefore, it is meaningful to investigate the possible cross-interactions of hIAPP and Aβ in both diseases. In this article, the segment 25–35 of Aβ was selected because Aβ 25–35 was a core region in the process of amyloid formation and showed similar aggregation tendency and toxicity with full-length Aβ. The electrospray ionization-ion mobility-mass spectrometry analysis and thioflavin T fluorescence kinetic analysis combined with transmission electron microscopy were used to explore the effects of the coexistence of Aβ 25–35 and hIAPP on the self-aggregation of both peptides and whether there was co-assembly in fibrillation. The results indicated that the aggregation of hIAPP and Aβ 25–35 had two nucleation stages in the binary mixtures. hIAPP and Aβ 25–35 had a high binding affinity and a series of hetero-oligomers formed in the mixtures of hIAPP and Aβ 25–35 in the early stage. The cross-reaction between hIAPP monomers and Aβ 25–35 monomers as well as a little of oligomers during primary nucleation stage could accelerate the aggregation of Aβ 25–35 . However, owing to the obvious difference in aggregation ability between hIAPP and Aβ 25–35 , this cross-interaction had no significant impact on the self-assembly of hIAPP. Our study may offer a better understanding for exploring the molecular mechanism of the association between AD and T2D observed in clinical and epidemiological studies and developing therapeutic strategies against amyloid diseases.
研究领域:
生物化学
·
神经科学
·
糖尿病研究
·
阿尔茨海默病研究
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Yuwen Guo,Kexu Bao,Xiaohui Wu,Dongli Han,Jichuan Zhang
Natural rubber particles (NRPs) are the main place of natural rubber biosynthesis and storage which exist as the organelle in the latex tube cells of rubber trees . Here, we observed the aggregation process from the morphology of rubber particles and correlated the aggregate structure with the mechanical properties. The rubber particle sizes were first examined by optical microscopy, and the distribution showed a Gaussian curve with an average diameter of 1200 nm. Scanning electron microscopy (SEM) was then used to photograph the smaller particles, which supported a Gaussian distribution for NRPs smaller than 200 nm in diameter. They collectively indicated a bimodal distribution of NRP size, consistent with the results of the laser particle size analyzer. The percentage of the small rubber particles was measured to be 68.3 % and 31.7 % for the large rubber particles. The aggregation process of NRPs was observed as membrane fusion , superimposed aggregation, followed by the concavity of the inner core from the outside, and finally the formation of aggregated state rubber. Subsequently, the natural rubber latex films were obtained by spreading the latex at room temperature. The green strength was tested in its naturally dried stacked aggregated state, reaching a notable strength of 8 MPa. This was about 7 times higher than that of the ribbed smoked sheet (RSS). In contrast, when the naturally dried rubber film was processed by high-temperature molding and low-temperature setting, its green strength dropped to the level of the RSS. It thus supports that the processing methods, such as high temperature and shearing , could significantly impact the structure and performance of natural rubber (NR). Consequently, excellent performance of elastomeric materials might be reached under low-temperature drying and normal-temperature vulcanization processing methods.
研究领域:
材料科学
·
聚合物科学
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）