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1.
Polymers (Basel) ; 16(8)2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38674999

ABSTRACT

The branched structures of dendronized polymers can provide good steric stabilization for metal nanoparticle catalysts. In this work, an amphiphilic dendronized copolymer containing hydrophilic branched triethylene glycol moieties and hydrophobic branched ferrocenyl moieties is designed and prepared by one-pot ring-opening metathesis polymerization, and is used as the stabilizer for metal (Au, Ag and Pd) nanoparticles. These metal nanoparticles (Au nanoparticles: 3.5 ± 3.0 nm; Ag nanoparticles: 7.2 ± 4.0 nm; Pd nanoparticles: 2.5 ± 1.0 nm) are found to be highly active in both the 4-nitrophenol reduction and Suzuki-Miyaura reactions. In the 4-nitrophenol reduction, Pd nanoparticles have the highest catalytic ability (TOF: 2060 h-1). In addition, Pd nanoparticles are also an efficient catalyst for Suzuki-Miyaura reactions (TOF: 1980 h-1) and possess good applicability for diverse substrates. The amphiphilic dendronized copolymer will open a new door for the development of efficient metal nanoparticle catalysts.

2.
Food Chem ; 449: 139114, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38581782

ABSTRACT

L-Tryptophan (L-Trp) is essential for the human body and can only be obtained externally. It is important to develop a method to efficiently detect L-Trp in food. In this work, ionic liquid (IL) modified poly(3,4-ethylendioxythiophene)/ Titanium carbide (PEDOT/Ti3C2TX) was used as a substrate material to improve detection sensitivity. Molecular imprinted polymers (MIP) film for specific recognition of L-Trp was fabricated on the surface of modified electrodes using electrochemical polymerization. The monitoring results showed that the molecularly imprinted electrochemical sensors (MIECS) exhibited good linearity ranges (10-6 - 0.1 µM and 0.1-100 µM) with a low detection limit (LOD) of 2.09 × 10-7 µM. In addition, the MIECS exhibited remarkable stability, reproducibility, and immunity to interference. A good recovery (93.54-99.59%) was demonstrated in the detection of milk. The sensor was expected to be developed as a highly selective and sensitive portable assay, and applied to the detection of L-Trp in food.


Subject(s)
Electrochemical Techniques , Ionic Liquids , Limit of Detection , Milk , Molecular Imprinting , Polymers , Titanium , Tryptophan , Milk/chemistry , Ionic Liquids/chemistry , Polymers/chemistry , Animals , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Tryptophan/analysis , Tryptophan/chemistry , Titanium/chemistry , Bridged Bicyclo Compounds, Heterocyclic/chemistry , Molecularly Imprinted Polymers/chemistry , Food Contamination/analysis , Electrodes , Reproducibility of Results
3.
World J Nucl Med ; 23(1): 33-42, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38595841

ABSTRACT

Objective The purpose of this study was to evaluate the prognostic significance of corrected baseline metabolic parameters in fluorodeoxyglucose positron emission tomography imaging ( 18 F-FDG PET/CT) for 3-year progression-free survival (PFS) in patients with primary diffuse large B cell lymphoma (DLBCL). Patients and Methods Retrospective clinical and pathological data were collected for 199 patients of DLBCL diagnosed between January 2018 and January 2021. All patients underwent 18 F-FDG PET/CT scans without any form of treatment. The corrected maximum standardized uptake value (corSUVmax), corrected mean standardized uptake value (corSUVmean), corrected whole-body tumor metabolic volume sum (corMTVsum), and corrected total lesion glycolysis of whole body (corTLGtotal) were corrected using the SUVmean in a 1-cm diameter mediastinal blood pool (MBP) from the descending thoracic aorta of patients. Kaplan-Meier survival curves and Cox regression were used to examine the predictive significance of corrected baseline metabolic parameters on 3-year PFS of patients. The incremental values of corrected baseline metabolic parameters were evaluated by using Harrell's C-indices, receiver operating characteristic, and Decision Curve Analysis. Results The multivariate analysis revealed that only the National Comprehensive Cancer Network (NCCN)-International Prognostic Index (IPI) and corMTVsum had an effect on 3-year PFS of patients ( p < 0.05, respectively). The Kaplan-Meier survival analysis demonstrated significant differences in PFS between the risk groups classified by corSUVsum, corMTVsum, and corTLGtotal (log-rank test, p < 0.05). The predictive model composed of corMTVsum and corTLGtotal surpasses the predictive performance of the model incorporating MTVsum and TLGtotal. The optimal performance was observed when corMTVsum was combined with NCCN-IPI, resulting in a Harrell's C index of 0.785 and area under the curve values of 0.863, 0.891, and 0.947 for the 1-, 2-, and 3-year PFS rates, respectively. Conclusion The corMTVsum offers significant prognostic value for patients with DLBCL. Furthermore, the combination of corMTVsum with the NCCN-IPI can provide an accurate prediction of the prognosis.

4.
Acta Biomater ; 178: 320-329, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38479677

ABSTRACT

Stress-induced corrosion impairs the mechanical integrity of magnesium (Mg) and its alloys as potential orthopedic implants. Although there has been extensive work reporting the effects of stress on Mg corrosion in vitro, the geometric design principles of the Mg-based orthopedic devices still remain largely unknown. In this work, a numerical simulation model mimicking fractured bone fixation and surgical animal models were applied to investigate the effects of the geometric design of Mg screws on the stress distribution and the stress-induced degradation behavior. Finite element (FE) analysis was used for calculation of stress concentrations around the Mg screws, with different thread type, thread pitch, and thread width. Afterward, the Mg screws of the pre-optimization and post-optimization groups exhibiting the highest and lowest stress concentrations, respectively, were implanted in the fractured distal femora and back subcutaneous tissue of rabbits. Encouragingly, there was a significant difference between the pre-optimization and the post-optimization groups in the degradation rate of the stressed screw parts located around the fracture line. Interestingly, there was no significant difference between the two groups in the degradation rate of the non-stressed screw parts. Consistently, the Mg screw post-optimization exhibited a significantly lower degradation rate than that pre-optimization in the back subcutaneous implantation model, which generated stress in the whole screw body. The alteration in geometric design did not affect the corrosion rate of the Mg screws in an immersion test without load applied. Importantly, an accelerated new bone formation with less fibrous encapsulation around the screws was observed in the Mg group post-optimization relative to the Mg group pre-optimization and the poly (lactic acid) group. Geometry optimization may be a promising strategy to reduce stress-induced corrosion in Mg-based orthopedic devices. STATEMENT OF SIGNIFICANCE: Stress concentrations influence corrosion characteristics of magnesium (Mg)-based implants. The geometric design parameters, including thread type, thread pitch, and thread width of the Mg screws, were optimized through finite element analysis to reduce stress concentrations in a fractured model. The Mg screws with triangular thread type, 2.25 mm pitch, and 0.3 mm thread width, exhibiting the lowest maximum von Mises stress, showed a significant decrease in the volume loss relative to the Mg screws pre-optimization. Compared with the Mg screw pre-optimization and the poly(lactic acid) screw, the Mg screw post-optimization favored new bone formation while inhibiting fibrous encapsulation. Collectively, optimization in the geometric design is a promising approach to reduce stress-induced corrosion in Mg-based implants.


Subject(s)
Femoral Fractures , Fracture Healing , Animals , Rabbits , Magnesium/pharmacology , Corrosion , Bone Screws , Femoral Fractures/surgery , Finite Element Analysis , Biomechanical Phenomena
5.
Int J Biol Macromol ; 266(Pt 1): 131248, 2024 May.
Article in English | MEDLINE | ID: mdl-38554912

ABSTRACT

Renewable biomass-based materials have a huge potential to replace petroleum-based products in food packaging. Herein, pectin/gelatin films loaded with curcumin and silver nanoparticles (AgNPs) are prepared by solution-pouring technology to serve as antimicrobial multifunctional food packaging films. AgNPs and curcumin are found to equally distribute in the films. Fourier transform infrared spectroscopy (FT-IR) reveal the hydrogen bonding and electrostatic interaction among curcumin, AgNPs, pectin and gelatin. The composite films show good antioxidant activity, mechanical performance, hydrophobicity and antibacterial ability. The films of P-GCA 0.5 showed 99.57 ± 0.16 % and 100 % inhibition against E. coli and S. aureus, respectively. The films also demonstrate excellent water vapor barrier qualities. In addition, the composite films possess pH-responsive color change behaviors from yellow (pH 3-8) to light red (pH 8-9) to dark red (pH 11-12), which is suitable for monitoring the freshness of shrimp packaging based on pH changes during deterioration process. As sustainable biomass-based materials, the multifunctional composite films are promising in intelligent food packaging applications.


Subject(s)
Anti-Bacterial Agents , Curcumin , Escherichia coli , Food Packaging , Gelatin , Metal Nanoparticles , Pectins , Silver , Staphylococcus aureus , Food Packaging/methods , Gelatin/chemistry , Silver/chemistry , Metal Nanoparticles/chemistry , Pectins/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Curcumin/chemistry , Curcumin/pharmacology , Escherichia coli/drug effects , Staphylococcus aureus/drug effects , Hydrogen-Ion Concentration , Antioxidants/chemistry , Antioxidants/pharmacology , Spectroscopy, Fourier Transform Infrared , Microbial Sensitivity Tests
6.
Biosens Bioelectron ; 251: 116119, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38342057

ABSTRACT

Poly (3,4-ethylenedioxythiophene) (PEDOT)-based molecularly imprinted electrochemical sensors have attracted widespread attention for monitoring contaminants in food and the environment. However, there are still problems such as poor hydrophilicity, easy agglomeration, and low selectivity in its preparation. In this work, a novel molecularly imprinted composite hollow sphere was prepared by a molecular imprinting technique using nitrogen-doped hollow carbon spheres as matrix material, and PEDOT and poly(methacrylic acid) as monomers. The selective binding capabilities and mechanism of the material to norfloxacin (NOR) were systematically investigated. Then the material-based sensor was constructed, and its electrochemical detection performance toward NOR was thoroughly studied. The sensor exhibited a wide linear range (0.0005-31 µM), a low detection limit (0.061 nM), satisfactory immunity to interference and stability. Besides, the sensor displayed better sensitivity and reliability (spiked recoveries of 98.0-105.2%, relative standard deviation of 3.45-5.69%) for detecting NOR in lake water, honey, and milk than high-performance liquid chromatography. This work provides a new strategy for developing poly(3,4-ethylenedioxythiophene)-based molecularly imprinted electrochemical sensors.


Subject(s)
Biosensing Techniques , Molecular Imprinting , Norfloxacin , Reproducibility of Results , Electrochemical Techniques/methods , Polymers/chemistry , Biosensing Techniques/methods , Molecular Imprinting/methods , Limit of Detection , Electrodes
7.
Environ Sci Pollut Res Int ; 31(13): 19815-19830, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38367117

ABSTRACT

Against the backdrop of ecological conservation and high-quality development in the Yangtze River Basin, there is an increasing demand for enhanced water pollution prevention and control in small watersheds. To delve deeper into the intricate relationship between pollutants and environmental features, as well as explore the key factors triggering pollution and their corresponding warning thresholds, this study was conducted along the Jiuqu River, a strategically managed unit in the upstream region of the Yangtze River, between 2022 and 2023. A total of seven monitoring sites were established, from which 161 valid water samples were collected. The k-nearest neighbors mutual information (KNN-MI) technique indicated that water temperature (WT) and relative humidity (RH) were the main environmental factors. The principal component analysis (PCA) of ten water quality parameters and three environmental factors unveiled the distinguishing characteristics of the primary pollution sources. Consequently, the pollution sources were categorized as treated wastewater > groundwater runoff > phytoplankton growth > abstersion wastewater > agricultural drainage. Furthermore, the regression decision tree (RDT) algorithm was used to explore the combined effects between pollutants and environmental factors, and to provide visual decision-making process and quantitative results for understanding the triggering mechanism of organic pollution in Jiuqu River. It conclusively identifies total phosphorus (TP) as the predominant triggering parameter with the threshold of 0.138 mg/L. The study is helpful to deal with potential water pollution problems preventatively and shows the interpretability and predictive performance of the RDT algorithm in water pollution prevention.


Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Environmental Monitoring/methods , Rivers , Wastewater , Water Pollutants, Chemical/analysis , Water Pollution/analysis , Water Quality , China , Environmental Pollutants/analysis
8.
Carbohydr Polym ; 327: 121677, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38171688

ABSTRACT

With the growing demand for eco-friendly materials in wearable smart electronic devices, renewable, biocompatible, and low-cost hydrogels based on natural polymers have attracted much attention. Cellulose, as one of the renewable and degradable natural polymers, shows great potential in wearable smart electronic devices. Multifunctional conductive cellulose-based hydrogels are designed for flexible electronic devices by adding sodium carboxymethyl cellulose and MXene into polyacrylic acid networks. The multifunctional hydrogels possess excellent mechanical property (stress: 310 kPa; strain: 1127 %), toughness (206.67 KJ m-3), conductivity (1.09 ± 0.12 S m-1) and adhesion (82.19 ± 3.65 kPa). The multifunctional conductive hydrogels serve as strain sensors (Gauge Factor (GF) = 5.79, 0-700 % strain; GF = 14.0, 700-900 % strain; GF = 40.36, 900-1000 % strain; response time: 300 ms; recovery time: 200 ms) and temperature sensors (Temperature coefficient of resistance (TCR) = 2.5755 °C-1 at 35 °C- 60 °C). The sensor detects human activities with clear and steady signals. A distributed array of flexible sensors is created to measure the magnitude and distribution of pressure and a hydrogel-based flexible touch keyboard is also fabricated to recognize writing trajectories, pressures and speeds. Furthermore, a flexible hydrogel-based supercapacitor powers the LED and exhibits good cyclic stability over 15,000 charge-discharge cycles.

9.
Article in English | MEDLINE | ID: mdl-38062739

ABSTRACT

Aim: Acetaminophen (APAP) is clinically recommended as analgesic and antipyretic among pregnant women. However, accumulating laboratory evidence shows that the use of APAP during pregnancy may alter fetal development. Since fetal stage is a susceptible window for early oogenesis, we aim to assess the potential effects of maternal administration of APAP on fetal oocytes. Results: Pregnant mice at 14.5 dpc (days post-coitus) were orally administered with APAP (50 and 150mg/kg.bw/day) for 3 days; meanwhile, 14.5 dpc ovaries were collected and cultured with APAP or its metabolite N-acetyl-p-benzoquinone imine (NAPQI; 5 and 15 µM) for 3 days. It showed that APAP caused meiotic aberrations in fetal oocytes through its metabolite NAPQI, including meiotic prophase I (MPI) progression delay and homologous recombination defects. Co-treatment with nicotinamide (NAM) or nicotinamide riboside chloride (NRC), nicotinamide adenine dinucleotide (NAD+) supplements, efficiently restored the MPI arrest, whereas the addition of the inhibitor of sirtuin 7 (SIRT7) invalidated the effect of the NAD+ supplement. In addition, RNA sequencing revealed distorted transcriptomes of fetal ovaries treated with NAPQI. Furthermore, the fecundity of female offspring was affected, exhibiting delayed primordial folliculogenesis and puberty onset, reduced levels of ovarian hormones, and impaired developmental competence of MII oocytes. Innovation: These findings provide the first known demonstration that NAPQI, converted from maternal administration of APAP, disturbs meiotic process of fetal oocytes and further impairs female fecundity in adulthood. The concomitant oral dosing with NAM further supports the benefits of NAD+ supplements on oogenesis. Conclusion: Short-term administration of APAP to pregnant mouse caused meiotic aberrations in fetal oocytes by its metabolite NAPQI, whereas co-treatment with NAD+ supplement efficiently relieves the adverse effects by interacting with SIRT7.

10.
Int J Biol Macromol ; 258(Pt 1): 128912, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38141716

ABSTRACT

Photocatalysts immobilized on hydrogels is a win-win mode, which not only improves photocatalysis but also successfully prevents catalyst loss, making it easy to separate and reuse during catalytic process. Here, ZnO-Ti3C2TX photocatalysts are loaded into the chitosan/polyacrylic acid hydrogel networks, realizing the efficiently photocatalytic degradation of norfloxacin. The chitosan-based composite hydrogel features rich functional groups and a dense pore structure, which is beneficial to antibiotic enrichment and photocatalytic degradation. The effects of different catalyst ratios, dosage, initial concentrations and pH on the degradation efficiency are investigated. The norfloxacin degradation rate constant is 0.012 min-1 and its degradation efficiency reaches up to 90 % after 240 min. Importantly, the photocatalytic composite hydrogel still retains 85 % degradation efficiency after 6 cycles. Moreover, e- plays a significant role in the degradation process. This work converts the traditional powder photocatalysts into bulk photocatalysts (photocatalytic hydrogels) to accomplish efficient degradation and rapid recycling for contaminant removal.


Subject(s)
Acrylic Resins , Chitosan , Zinc Oxide , Zinc Oxide/chemistry , Norfloxacin , Chitosan/chemistry , Hydrogels , Titanium/chemistry
11.
Dalton Trans ; 52(44): 16345-16355, 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37856218

ABSTRACT

Exploiting high-efficiency and durable electrocatalysts toward the methanol oxidation reaction (MOR) is crucial for the advancement of direct methanol fuel cells (DMFCs). Herein, we demonstrate the loading of platinum-palladium bimetallic nanoparticles (Pt-Pd NPs) onto poly(3,4-ethylenedioxythiophene) (PEDOT)-embellished titanium carbide (Ti3C2Tx) nanosheets as the electrocatalyst (Ti3C2Tx/PEDOT/Pt-Pd) via a facile and rapid chemical reduction-assisted one-pot hydrothermal process. The structural and morphological analyses of Ti3C2Tx/PEDOT/Pt-Pd indicate that the three-dimensional (3D) hybrid structure formed between PEDOT and Ti3C2Tx provides a sizable active surface and more active sites, which enhances the homogeneous dispersion of the Pt-Pd NPs and facilitates mass transfer. The Schottky junctions formed between PEDOT and Pt-Pd NPs contribute to charge transfer. The electronic effects and synergistic interactions between the support and catalyst favor the electrocatalytic activity of the catalyst. The electrochemical test results reveal that the Ti3C2Tx/PEDOT/Pt-Pd catalyst has prominent electrocatalytic capability for the MOR. Compared with Ti3C2Tx/Pt-Pd and commercial Pt/C catalysts, the Ti3C2Tx/PEDOT/Pt-Pd catalyst has a larger electrochemical activity surface area (ECSA = 122 m2 g-1) and higher mass activity (MA = 1445.4 mA mg-1), as well as better CO tolerance and more reliable long-term durability (a peak current density retention of 71% after 5200 s).

12.
Exp Biol Med (Maywood) ; 248(6): 508-518, 2023 03.
Article in English | MEDLINE | ID: mdl-37070250

ABSTRACT

Early diagnosis can help prevent and reduce the adverse effects of gestational diabetes mellitus (GDM). This study intended to investigate key circulating long non-coding RNAs (lncRNAs) as novel biomarkers for diagnosis of GDM at the early stages. First, lncRNA microarray analysis was conducted for plasma samples of GDM women before delivery and 48 h after delivery. The expression of differentially expressed lncRNAs in clinical samples at different trimesters was randomly validated by quantitative polymerase chain reaction (PCR). Moreover, the correlation between lncRNA expression and oral glucose tolerance test (OGTT) level in GDM women during the second trimester was analyzed, followed by evaluating the diagnostic value of key lncRNAs during different trimesters using receiver operating characteristic (ROC) curve. Higher NONHSAT054669.2 expression and lower ENST00000525337 expression were revealed in GDM women before delivery relative to 48 h after delivery (P < 0.05). The expression of NONHSAT054669.2 and ENST00000525337 in GDM women during the first and second trimesters was dramatically higher than pregnant women (P < 0.05) with normal glucose tolerance (NGT). During the second trimester, NONHSAT054669.2 expression was positively related to OGTT level at 1 h (r = 0.41455, P < 0.001). Furthermore, ROC curve analysis revealed that ENST00000525337 alone, NONHSAT054669.2 alone, and their combination had high diagnostic value for GDM during the first (area under the ROC curve (AUC) = 0.979, 0.956, and 0.984, respectively) and second (AUC = 0.829, 0.809, and 0.838, respectively) trimesters (all P < 0.001). The plasma level of NONHSAT054669.2 and ENST00000525337 may be applied as novel diagnostic biomarkers for early diagnosis of GDM.


Subject(s)
Diabetes, Gestational , RNA, Long Noncoding , Pregnancy , Female , Humans , Diabetes, Gestational/diagnosis , Diabetes, Gestational/genetics , RNA, Long Noncoding/genetics , Biomarkers , Glucose Tolerance Test , ROC Curve , Blood Glucose/analysis
14.
Carbohydr Polym ; 310: 120726, 2023 Jun 15.
Article in English | MEDLINE | ID: mdl-36925251

ABSTRACT

Biopolymer-derived hydrogels with low-cost and sustainable features have been considered as fascinating supported materials for metal nanoparticles. Cellulose, as the most abundant biopolymer, is a renewable raw material to prepare biopolymer-derived hydrogels for catalysis. Here, a cellulose-based hydrogel is designed to load bimetallic (AuAg, AuPd and AgPd) nanoparticles. 4-Nitrophenol reduction and Suzuki-Miyaura coupling reactions are selected to evaluate and compare the catalytic performance of the resulting bimetallic nanoparticle-loaded cellulose-based composite hydrogels. The bimetallic nanocomposite hydrogels are easy to be recycled over 10 times during the catalytic experiments and possess good applicability and generality for various substrates. The catalytic activity of bimetallic nanocomposite hydrogels was compared with recent literatures. In addition, the possible catalytic mechanism is also proposed. This work is expected to give a new insight for designing and preparing bimetallic nanoparticle-based cellulose hydrogels and proves its applicability and prospect in the catalytic field.

15.
Nat Prod Res ; 37(18): 3152-3157, 2023.
Article in English | MEDLINE | ID: mdl-36412543

ABSTRACT

Irritable bowel syndrome (IBS) is a very common refractory disease. Its exact pathophysiological mechanism is still unclear. Despite the availability of plentiful drugs to control IBS, most patients do not respond well. Ginsenoside Rd is one of the major active components of Panax ginseng, which has been verified to produce various pharmacological actions. However, the role of ginsenoside Rd in modulating smooth muscle contractility is still undefined. The aim of this study is to investigate the effects of ginsenoside Rd on intestinal contractility and related mechanisms in IBS.

16.
J Multidiscip Healthc ; 15: 907-920, 2022.
Article in English | MEDLINE | ID: mdl-35519154

ABSTRACT

Progress in medical and surgical care has tremendously improved the survival rates of children with congenital heart disease (CHD). However, reduced aerobic capacity and health-related issues remain a threaten to quality survival and prevention of related complications among children and adolescents with CHD. This research program aims to develop and evaluate a WeChat-based health platform (HeartFIT) to facilitate cardiac rehabilitation and promote physical fitness for this rapidly expanding young population. The study protocol describes the use of an iterative process of using a mixed-methods strategy to develop, refine, and pilot test the proposed HeartFIT platform. A sequential problem-solving process comprising four iterative phases with ongoing end-user input will be implemented. In phase 1, relevant literature was systematically reviewed (completed) and then child-parent dyads will be interviewed to understand the broad context and the requirements and considerations of the target population toward the WeChat-based rehabilitation platform. In phase 2, key features and priority functionalities for the platform will be ideated and refined, and a digital interactive prototype will be created. In phase 3, heuristic evaluation and three rounds of end-user testing will be conducted to ensure further refinement and usability of the prototype. In phase 4, a prospective pilot study will be performed to investigate the feasibility, acceptability, and preliminary efficacy of the developed platform over a 12-week intervention period. If HeartFIT intervention is feasible, acceptable, and demonstrates promising efficacy, an adequately powered randomized controlled trial (future work) will be deployed to test the real-world effectiveness of the intervention.

17.
Redox Biol ; 51: 102269, 2022 05.
Article in English | MEDLINE | ID: mdl-35276443

ABSTRACT

Endothelial oxidative stress and inflammation attributable to the activation of a Nox2-NADPH oxidase are key features of many cardiovascular diseases. Here, we report a novel small chemical compound (LMH001, MW = 290.079), by blocking phosphorylated p47phox interaction with p22phox, inhibited effectively angiotensin II (AngII)-induced endothelial Nox2 activation and superoxide production at a small dose (IC50 = 0.25 µM) without effect on peripheral leucocyte oxidative response to pathogens. The therapeutic potential of LMH001 was tested using a mouse model (C57BL/6J, 7-month-old) of AngII infusion (0.8 mg/kg/d, 14 days)-induced vascular oxidative stress, hypertension and aortic aneurysm. Age-matched littermates of p47phox knockout mice were used as controls of Nox2 inhibition. LMH001 (2.5 mg/kg/d, ip. once) showed no effect on control mice, but inhibited completely AngII infusion-induced excess ROS production in vital organs, hypertension, aortic walls inflammation and reduced incidences of aortic aneurysm. LMH001 effects on reducing vascular oxidative stress was due to its inhibition of Nox2 activation and was abrogated by knockout of p47phox. LMH001 has the potential to be developed as a novel drug candidate to treat oxidative stress-related cardiovascular diseases.


Subject(s)
Aortic Aneurysm , Hypertension , Angiotensin II/metabolism , Animals , Aortic Aneurysm/chemically induced , Aortic Aneurysm/genetics , Aortic Aneurysm/prevention & control , Hypertension/chemically induced , Hypertension/drug therapy , Hypertension/genetics , Inflammation , Mice , Mice, Inbred C57BL , Mice, Knockout , NADPH Oxidase 2/genetics , NADPH Oxidases/genetics , NADPH Oxidases/metabolism , Oxidative Stress , Reactive Oxygen Species/pharmacology
18.
Antioxidants (Basel) ; 10(9)2021 Aug 26.
Article in English | MEDLINE | ID: mdl-34572995

ABSTRACT

The p47phox is a key regulatory subunit of Nox2-containing NADPH oxidase (Nox2) that by generating reactive oxygen species (ROS) plays an important role in Angiotensin II (AngII)-induced cardiac hypertrophy and heart failure. However, the signalling pathways of p47phox in the heart remains unclear. In this study, we used wild-type (WT) and p47phox knockout (KO) mice (C57BL/6, male, 7-month-old, n = 9) to investigate p47phox-dependent oxidant-signalling in AngII infusion (0.8 mg/kg/day, 14 days)-induced cardiac hypertrophy and cardiomyocyte apoptosis. AngII infusion resulted in remarkable high blood pressure and cardiac hypertrophy in WT mice. However, these AngII-induced pathological changes were significantly reduced in p47phox KO mice. In WT hearts, AngII infusion increased significantly the levels of superoxide production, the expressions of Nox subunits, the expression of PKCα and C-Src and the activation of ASK1 (apoptosis signal-regulating kinase 1), MKK3/6, ERK1/2, p38 MAPK and JNK signalling pathways together with an elevated expression of apoptotic markers, i.e., γH2AX and p53 in the cardiomyocytes. However, in the absence of p47phox, although PKCα expression was increased in the hearts after AngII infusion, there was no significant activation of ASK1, MKK3/6 and MAPKs signalling pathways and no increase in apoptosis biomarker expression in cardiomyocytes. In conclusion, p47phox-dependent redox-signalling through ASK1, MKK3/6 and MAPKs plays a crucial role in AngII-induced cardiac hypertrophy and cardiomyocyte apoptosis.

19.
J Colloid Interface Sci ; 604: 281-291, 2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34271489

ABSTRACT

Due to the good electrical, optical, magnetic, catalytic properties, transition metal nanoparticles (TMNPs) have been becoming more and more interesting in the fileds of environment, material, biomedicine, catalysis, and so on. Here, tannic acid (TA) is used as a green and efficient stabilizer to fabricate all kinds of TMNPs including AuNPs, AgNPs, CuNPs and PdNPs. These TMNPs possess small sizes ranging from 1 nm to 6 nm, which is conducive to several catalytic reactions in aqueous solution, such as 4-nitrophenol (4-NP) reduction, CuAAC reactions and Suzuki-Miyaura coupling reactions. AuNPs and PdNPs are found to have distinctly higher catalytic activities than AgNPs and CuNPs in the 4-NP reduction process. Especially, PdNPs show the highest catalytic activities with TOF up to 7200 h-1 in the 4-NP reduction. Furthermore, PdNPs also exhibit satisfying catalytic performance in the Suzuki-Miyaura coupling process, and CuNPs are catalytically active in the copper-catalyzed azide alkyne cycloaddition (CuAAC) reactions. The applicability and generality of PdNPs and CuNPs are respectively confirmed via the reaction between different substrates in the Suzuki-Miyaura coupling reactions and the CuAAC reactions. This work present a simple, fast, green and efficient strategy to synthesize TMNPs for multiple catalysis.


Subject(s)
Metal Nanoparticles , Catalysis , Gold , Nitrophenols , Palladium , Tannins
20.
Bioact Mater ; 6(10): 3231-3243, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33778201

ABSTRACT

As one of the most promising fixators developed for anterior cruciate ligament (ACL) reconstruction, biodegradable magnesium (Mg)-based interference screws have gained increasing attention attributed to their appropriate modulus and favorable biological properties during degradation after surgical insertion. However, its fast degradation and insufficient mechanical strength have also been recognized as one of the major causes to limit their further application clinically. This review focused on the following four parts. Firstly, the advantages of Mg or its alloys over their counterparts as orthopaedic implants in the fixation of tendon grafts in ACL reconstruction were discussed. Subsequently, the underlying mechanisms behind the contributions of Mg ions to the tendon-bone healing were introduced. Thirdly, the technical challenges of Mg-based interference screws towards clinical trials were discussed, which was followed by the introduction of currently used modification methods for gaining improved corrosion resistance and mechanical properties. Finally, novel strategies including development of Mg/Titanium (Ti) hybrid fixators and Mg-based screws with innovative structure for achieving clinically customized therapies were proposed. Collectively, the advancements in the basic and translational research on the Mg-based interference screws may lay the foundation for exploring a new era in the treatment of the tendon-bone insertion (TBI) and related disorders.

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