Antibacterial activities of various spherical zinc oxide nanoparticles and nano special morphological structures including quantum dots, nanorod arrays, nanoporous shapes and needle-like crystals had been investigated...Antibacterial activities of various spherical zinc oxide nanoparticles and nano special morphological structures including quantum dots, nanorod arrays, nanoporous shapes and needle-like crystals had been investigated as new nanomedicine compounds. Also antibacterial activity based on minimal inhibitory concentration and the growth inhibitory zone (well method) was evaluated. ZnO nanostructures were fabricated by novel hydrolysis sol-gel-hydrothermal process followed with rapid quenching as new technique using glycerine, vegetable fatty esters such as coconut, sunflower and Lauric alcohol ethoxylated as organic templates soluble in eco-friendly nanofluids. The results showed that Bacillus anthracis and Pseudomonas aerogenes were extremely sensitive to treatment with unique ZnO nanostructured. Their growth inhibitory zone presented 30 mm and 25 mm inhibition zone with better inhibitory effect compared to the Gentamicin antibiotic standard. ZnO nanostructures had also been indicated to have a wide range of antibacterial activities against both Gram-positive and Gram-negative bacteria especially more effective on (gr+) species using the growth inhibitory zone. We could design and make significant formulations of fatty acids and esters-capped ZnO quantum dots nanofluids which created high promising agents for controlling Anthrax, Staphylococcus epidermidis and their influences in antimicrobial properties with low cost for future.展开更多
Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(...Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.展开更多
In this study,thyme essential oil(TEO)nanoemulsion(tPTNs)was constructed with transglutaminase(TGase)-modified potato protein,and its antibacterial activity and mechanism of action were evaluated and explored.Results ...In this study,thyme essential oil(TEO)nanoemulsion(tPTNs)was constructed with transglutaminase(TGase)-modified potato protein,and its antibacterial activity and mechanism of action were evaluated and explored.Results indicated that tPTNs exhibited great antibacterial activity against both Staphylococcus aureus and Escherichia coli,with minimal inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of 2.5 and 5.0 mg/mL,respectively.Also,the antibacterial effects of tPTNs were concentration-dependent.We observed a significant decrease in the absolute value of the zeta potential,and significant increases in particle size,cell membrane hydrophobicity,conductivity,the release of metal ions,and the leakage of nucleic acid as the concentration of tPTNs increased from 0 mg/mL to MBC.Furthermore,sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE)demonstrated that protein synthesis was inhibited or even disrupted.Analysis by liquid chromatography-mass spectrometry(LC-MS)indicated that treatment with tPTNs caused significant changes in bacterial metabolites,1117 and 692 differential metabolites being found for S.aureus and E.coli,respectively.The differential metabolites were involved in nucleotide metabolism,amino acid metabolism,tricarboxylic acid cycle and other metabolic pathways.These findings provide valuable insights for the application of thyme essential oil as an efficient antibacterial agent and for the understanding of its mechanism of action.展开更多
new heterocyclic dipeptide with a highly functionalized 1,2-oxazadecaline core,named trichodermamide H(1),and three known analogues,along with three known polyketides,were isolated from the fermentation extract of the...new heterocyclic dipeptide with a highly functionalized 1,2-oxazadecaline core,named trichodermamide H(1),and three known analogues,along with three known polyketides,were isolated from the fermentation extract of the mangrovederived fungus Penicillium janthinellum XLN32122.The structure of 1 was elucidated on the basis of extensive 1D and 2D NMR spectra data analysis,HR-ESI-MS,electronic circular dichroism(ECD)calculations.Trichodermamide B(3)exhibited better inhibitory effect on nitric oxide(NO)production in lipopolysaccharide(LPS)induced RAW 264.7 cells with an IC_(50)value of(13.13±0.005)μmol/L than that of the positive control dexamethasone[IC_(50)=(136.84±1.33)μmol/L].Compound 3 exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus(MRSA)with an IC_(50)value of 12.5μg/mL,while the positive control vancomycin showed an IC_(50)value of 1.563μg/mL.展开更多
Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticle...Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.展开更多
Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The a...Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.展开更多
Metal nanoclusters(MNCs),comprising several to hundreds of metal atoms,have attracted significant research interest owing to their distinctive physicochemical properties.Reticular frameworks(RFs)with ordered porous st...Metal nanoclusters(MNCs),comprising several to hundreds of metal atoms,have attracted significant research interest owing to their distinctive physicochemical properties.Reticular frameworks(RFs)with ordered porous structures,including metalorganic frameworks(MOFs),covalent organic frameworks(COFs),hydrogen-bonded organic frameworks(HOFs),and supramolecular organic frameworks(SOFs),possess a variety of unique properties due to their high crystallinity,high porosity,large surface area,and adjustable structure.The integration of MNCs with RFs endows the resulting composites with desirable features(e.g.,enhanced and tunable optical properties,improved catalytic and photophysical activities,selective molecular recognition),which facilitates a broad spectrum of biomedical applications and advancing the development of integrated theranostic nanoplatforms.This review summarizes recent advances in the synthesis and biomedical applications of various MNCs/RFs composites.We systematically categorize and evaluate key strategies for incorporating MNCs into four types of RFs(MOFs,COFs,HOFs,and SOFs)while discussing the advantages and limitations of each approach.The biomedical applications of these composites are comprehensively reviewed,encompassing biosensing,bioimaging,antitumor therapy,and antibacterial treatments.Finally,the review addresses current challenges and outlines future research directions,with the aim of guiding the rational design of novel MNCs/RFs composites,enabling precise control over their structures and functions toward advanced biomedical applications.展开更多
Plantago major L.,commonly known as plantain,waybread,or dooryard plantain,is a versatile medicinal plant with multiple therapeutic applications.Traditionally,various parts of the plant have been formulated into syrup...Plantago major L.,commonly known as plantain,waybread,or dooryard plantain,is a versatile medicinal plant with multiple therapeutic applications.Traditionally,various parts of the plant have been formulated into syrups,drops,ointments,vaginal suppositories,gargles,and roasted preparations to treat diverse ailments,such as liver disorders,earaches,epilepsy,asthma,stomachaches,diarrhea,constipation,polymenorrhea,and uterine disorders.The plant contains clinically valuable bioactive compounds,including polysaccharides,flavonoids,lipids,iridoid glycosides,caffeic acid derivatives,terpenoids,alkaloids,and organic acids.These bioactive constituents are the primary contributors to the plant’s broad spectrum of biological activities,including antioxidant,anti-inflammatory,antibacterial,antidiarrheal,hepatoprotective,antiviral,antiphage,antinociceptive,antiulcerogenic,antigenotoxic,and immunomodulatory effects of the plant.This review comprehensively summarizes the phytochemical composition,traditional medicinal applications,and biological properties of this multifunctional medicinal plant.展开更多
The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier t...The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and ultra-depth microscope.The results show that the antibacterial adhesive can effectively inhibit the growth of sulfur-oxidizing bacteria in seawater,hinder their metabolism to produce biological sulfate,and reduce the formation of destructive product gypsum.The mineral composition and thermal analysis showed that the peak value of plaster diffraction peak and the mass loss of plaster dehydration in antibacterial adhesive group were significantly lower than those in blank group(without protective coating group).In addition,the electric flux of chloride ions(>400 C)in the blank group of mortar samples was higher than that in the antibacterial adhesive group(<200 C),indicating that the antibacterial adhesive can effectively reduce the permeability of chloride ions in mortar,and thus hinder the Cl-erosion in seawater.展开更多
Aggregation-induced emission(AIE)polymers have been extensively studied;however,the integration of AIE units into polyelectrolytes remains largely limited by the laborious multistep synthesis of pre-designed emissive ...Aggregation-induced emission(AIE)polymers have been extensively studied;however,the integration of AIE units into polyelectrolytes remains largely limited by the laborious multistep synthesis of pre-designed emissive monomers.Herein,we report a one-pot multicomponent polymerization method that directly produces main-chain charged polyelectrolytes with intrinsic AIE characteristics from non-emissive building blocks.By optimizing the monomer structures and reaction conditions,a series of soluble high-molecular-weight polymers with welldefined backbones were obtained in high yields.The resulting polyelectrolytes displayed robust AIE behavior,exhibiting fluorescence enhancement up to about 60-fold in an aqueous environment,and maintained excellent thermal stability.Owing to their cationic backbones,these polymers interact strongly with microbial surfaces and exhibit remarkable antimicrobial activities.This study establishes a synthetically efficient route to AIE polyelectrolytes and highlights their potential applications as multifunctional materials for bioimaging,antimicrobial therapy,and other applications.展开更多
Novel antibacterial strategies such as antibacterial photodynamic therapy(aPDT)and photothermal therapy(PTT)have gained significant attention,however,relying on a single-treatment approach still faces challenges of in...Novel antibacterial strategies such as antibacterial photodynamic therapy(aPDT)and photothermal therapy(PTT)have gained significant attention,however,relying on a single-treatment approach still faces challenges of insufficient therapeutic efficiency and the potential for drug resistance.In this study,a multimodal synergistic antibacterial nanoplatform by coupling a carbon monoxide(CO)donor(4-(3-hydroxy-4-oxo-4H-chromen-2-yl)benzoic acid(4-BA))with carbon dots(CDs)is developed,referred to as CDs-CO,which integrates multiple antibacterial modes of aPDT,PTT,and gas therapy.This nanoplatform is designed for highly efficient antibacterial action with a low risk of inducing drug resistance.CDs are engineered to possess tailored functions,including deep-red light-triggered heat and singlet oxygen(^(1)O_(2))production.After modification with 4-BA and exposure to 660 nm laser irradiation,CDs-CO exhibits favorable photothermal conversion efficiency(η=52.7%),robust ^(1)O_(2) generation,and ^(1)O_(2)-activated CO release.Antibacterial experiments demonstrated the excellent sterilization effects of CDs-CO against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus),underscoring the enhanced antibacterial efficiency of this multimodal nanoplatform.This study offers a rational approach for designing multimodal synergistic antibacterial platforms,highlighting their potential for effectively treating bacterial infections.展开更多
Plant bacterial diseases cause significant harm to agricultural production because of their frequent,intermittent and regional outbreaks.Currently,chemical control is still a more effective method for bacterial diseas...Plant bacterial diseases cause significant harm to agricultural production because of their frequent,intermittent and regional outbreaks.Currently,chemical control is still a more effective method for bacterial disease.To develop new,efficient and safe antibacterial agrochemicals,we summarize the research progress of compounds with antibacterial activities in the past ten years,classify them according to their active skeletons,and discuss their structure-activity relationships and mechanisms of action.Finally,the development trend of antibacterial agrochemicals was prospected.This review provides valuable information for the development of antibacterial agrochemicals.展开更多
Constructing nanofibers with specific therapeutic effects against cancer is a challenge.Here,we present the synthesis approach and application prospects of supramolecular nanofibers,which are based on cucurbit[8]uril(...Constructing nanofibers with specific therapeutic effects against cancer is a challenge.Here,we present the synthesis approach and application prospects of supramolecular nanofibers,which are based on cucurbit[8]uril(CB[8])as the host and terpyridine lanthanum ions metal complex as the vip,constructed by layer-by-layer self-assembly through supramolecular interaction.Moreover,nanofibers with lanthanide luminescence properties exhibit surprising pH-responsive deformation properties and antibacterial behavior.In the tumor micro-environment,the dramatic reduction in the size of the nanofibers enables specific and hierarchical release of anticancer drugs in tumor cells to exert an advanced therapeutic effect.In addition,the synergistic therapeutic efficacy was achieved by reducing the excess of Gram-positive and Gram-negative bacteria surrounding tumor cells.The novel supramolecular nanofibers with sequential drug release and combined therapeutic mode provide new guidance for the synthesis of drug carrier materials and direction for the promotion of nanomaterial-mediated cancer therapy.展开更多
The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivi...The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.展开更多
[Objectives]To evaluate the in vitro antibacterial,antioxidant,andα-glucosidase inhibitory activities of the ethanol total extract and four different polarity fractions(n-butanol,ethyl acetate,petroleum ether,and wat...[Objectives]To evaluate the in vitro antibacterial,antioxidant,andα-glucosidase inhibitory activities of the ethanol total extract and four different polarity fractions(n-butanol,ethyl acetate,petroleum ether,and water)of Pilea peltata Hance,so as to provide a reference for its further development and research.[Methods]The antibacterial activity of P.peltata was evaluated in vitro by determining the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of its ethanol total extract and four different polarity fractions against seven test bacterial strains using the broth microdilution method.The in vitro antioxidant activity was investigated through DPPH radical,hydroxyl radical,and superoxide anion radical scavenging assays,with vitamin C(Vit C)as the positive control and the half maximal scavenging concentration(IC 50)as the evaluation indicator.The in vitroα-glucosidase inhibitory activity was assessed by measuring the peak area of p-nitrophenol(PNP),the hydrolysis product of 4-nitrophenylα-D-glucopyranoside(PNPG),via high-performance liquid chromatography(HPLC),using the half maximal inhibitory concentration(IC_(50))as the evaluation indicator.[Results]Both the ethanol total extract and the four different polarity fractions of P.peltata exhibited significant in vitro anti-Streptococcus pneumoniae activity.The DPPH radical scavenging capacities of the ethanol total extract and the various fractions were all weaker than that of VitC,with the order of efficacy being:n-butanol fraction>ethanol total extract>ethyl acetate fraction>petroleum ether fraction>aqueous fraction.For hydroxyl radical scavenging activity,the efficacy order of P.peltata fractions was:n-butanol extract>ethyl acetate extract>ethanol total extract>petroleum ether extract>aqueous extract.Notably,the n-butanol fraction(IC_(50)=0.068±0.001)demonstrated stronger activity than VitC(IC_(50)=0.097±0.001).The activity of the ethyl acetate fraction(IC_(50)=0.096±0.004)was comparable to that of VitC(IC_(50)=0.097±0.001).The superoxide anion scavenging capacities of the ethanol total extract and different polarity fractions from P.peltata were all weaker than that of VitC,with the order of efficacy being:n-butanol fraction>ethyl acetate fraction>ethanol total extract>petroleum ether fraction>aqueous fraction.The ethanol total extract and aqueous fraction of Pilea peltata showed no significant in vitroα-glucosidase inhibitory activity.Compared with the acarbose group,the IC 50 values of the ethyl acetate fraction and the n-butanol fraction both showed highly significant differences(P<0.01).[Conclusions]This study provides an experimental basis for the pharmacodynamic study and active component study of P.peltata.展开更多
A microbial strain designated Bacillus licheniformis QX928 was screened from hot springs in Sichuan Province,China,and a compound generated in the culture of this strain clearly inhibited Pseudomonas aeruginosa ATCC27...A microbial strain designated Bacillus licheniformis QX928 was screened from hot springs in Sichuan Province,China,and a compound generated in the culture of this strain clearly inhibited Pseudomonas aeruginosa ATCC27853.The measured minimum inhibitory and lowest bactericidal concentrations were(13±0.17)and(22±0.72)mg L^(-1),respectively.The compound was identified as 3-isopropylhexahydro-4H-pyrido[1,2-α]pyrazine-1,4(6H)-dione(IPHPPD).A Sci Finder search revealed that IPHPPD could be the first compound synthesized by microorganisms that had both antibacterial and anti-quorum sensing properties.At low concentrations,IPHPPD interfered with the signaling factors and population effects of P.aeruginosa,thereby altering the biofilm morphology and structure.IPHPPD more strongly inhibited P.aeruginosa at high concentrations,primarily by reducing its virulence factors,cell membrane permeability and energy metabolism.A transcriptome analysis highlighted the role of IPHPPD in the transcriptional regulation of cellular metabolism and quorum sensing.Thus,the results of this study provide critical evidence that IPHPPD is a potential target for drug development to prevent and treat diseases in animals.展开更多
Hydrogen peroxide(H_(2)O_(2))is a versatile oxidant with significant applications,particularly in regulating the microenvironment for healthcare purposes.Herein,a rational design of the photoanode is implemented to en...Hydrogen peroxide(H_(2)O_(2))is a versatile oxidant with significant applications,particularly in regulating the microenvironment for healthcare purposes.Herein,a rational design of the photoanode is implemented to enhance H_(2)O_(2) production by oxidizing H_(2)O in a portable photoelectrocatalysis(PEC)device.The obtained solution from this system is demonstrated for effective bactericidal activity against Staphylococcus aureus and Escherichia coli,while maintaining low toxicity toward hippocampal neuronal cells.The photoanode is achieved by Mo-doped BiVO4 films,which are subsequently loaded with cobalt-porphyrin(Co-py)molecules as a co-catalyst.As a result,the optimal performance for H_(2)O_(2) production rate was achieved at 8.4μmol h^(−1) cm^(−2),which is 1.8 times that of the pristine BiVO4 photoanode.Density functional theory(DFT)simulations reveal that the improved performance results from a 1.1 eV reduction in the energy of the rate-determining step of·OH adsorption by the optimal photoanode.This study demonstrates a PEC approach for promoting H_(2)O_(2) production by converting H_(2)O for antibacterial purposes,offering potential applications in conventionally controlling microenvironments for healthcare applications.展开更多
Background: Mass drug administration(MDA)is a strategy to improve health at the population level through widespread delivery of medicine in a community.We surveyed the literature to summarize the benefits and potentia...Background: Mass drug administration(MDA)is a strategy to improve health at the population level through widespread delivery of medicine in a community.We surveyed the literature to summarize the benefits and potential risks associated with MDA of antibacterials,focusing predominantly on azithromycin as it has the greatest evidence base.Main body: High-quality evidence from randomized controlled trials(RCTs)indicate that MDA-azithromycin is effective in reducing the prevalence of infection due to yaws and trachoma.In addition,RCTs suggest that MDA-azithromycin reduces under-five mortality in certain low-resource settings that have high childhood mortality rates at baseline.This reduction in mortality appears to be sustained over time with twice-yearly MDA-azithromycin,with the greatest effect observed in children<1 year of age.In addition,observational data suggest that infections such as skin and soft tissue infections,rheumatic heart disease,acute respiratory illness,diarrheal illness,and malaria may all be treated by azithromycin and thus incidentally impacted by MDA-azithromycin.However,the mechanism by which MDA-azithromycin reduces childhood mortality remains unclear.Verbal autopsies performed in MDA-azithromycin childhood mortality studies have produced conflicting data and are underpowered to answer this question.In addition to benefits,there are several important risks associated with MDA-azithromycin.Direct adverse effects potentially resulting from MDA-azithromycin include gastrointestinal side effects,idiopathic hypertrophic pyloric stenosis,cardiovascular side effects,and increase in chronic diseases such as asthma and obesity.Antibacterial resistance is also a risk associated with MDA-azithromycin and has been reported for both gram-positive and enteric organisms.Further,there is the risk for cross-resistance with other antibacterial agents,especially clindamycin.Conclusions: Evidence shows that MDA-azithromycin programs may be beneficial for reducing trachoma,yaws,and mortality in children<5 years of age in certain under-resourced settings.However,there are significant potential risks that need to be considered when deciding how,when,and where to implement these programs.Robust systems to monitor benefits as well as adverse effects and antibacterial resistance are warranted in communities where MDA-azithromycin programs are implemented.展开更多
Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial property.However,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are...Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial property.However,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water pollution.In this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing agent.Experimental analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag NPs.The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation.After the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite hydrogel.The inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag NPs.The prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.展开更多
Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates...Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte.The influence of varying ZnO concentrations on the microstructure,corrosion resistance,and antibacterial properties of the coating was examined through microstructure analysis,immersion tests,electrochemical experiments,and antibacterial assays.The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy.Specifically,when the ZnO concentration in the electrolyte was 5 g/L,the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO.Moreover,the antibacterial efficacy of ZnO+MAO coating,prepared with a ZnO concentration of 5 g/L,surpassed 95%after 24 h of co-culturing with Staphylococcus aureus(S.aureus).The nano-ZnO+MAO-coated alloy exhibited exceptional degradation resistance,corrosion resistance,and antibacterial effectiveness.展开更多
文摘Antibacterial activities of various spherical zinc oxide nanoparticles and nano special morphological structures including quantum dots, nanorod arrays, nanoporous shapes and needle-like crystals had been investigated as new nanomedicine compounds. Also antibacterial activity based on minimal inhibitory concentration and the growth inhibitory zone (well method) was evaluated. ZnO nanostructures were fabricated by novel hydrolysis sol-gel-hydrothermal process followed with rapid quenching as new technique using glycerine, vegetable fatty esters such as coconut, sunflower and Lauric alcohol ethoxylated as organic templates soluble in eco-friendly nanofluids. The results showed that Bacillus anthracis and Pseudomonas aerogenes were extremely sensitive to treatment with unique ZnO nanostructured. Their growth inhibitory zone presented 30 mm and 25 mm inhibition zone with better inhibitory effect compared to the Gentamicin antibiotic standard. ZnO nanostructures had also been indicated to have a wide range of antibacterial activities against both Gram-positive and Gram-negative bacteria especially more effective on (gr+) species using the growth inhibitory zone. We could design and make significant formulations of fatty acids and esters-capped ZnO quantum dots nanofluids which created high promising agents for controlling Anthrax, Staphylococcus epidermidis and their influences in antimicrobial properties with low cost for future.
文摘Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.
文摘In this study,thyme essential oil(TEO)nanoemulsion(tPTNs)was constructed with transglutaminase(TGase)-modified potato protein,and its antibacterial activity and mechanism of action were evaluated and explored.Results indicated that tPTNs exhibited great antibacterial activity against both Staphylococcus aureus and Escherichia coli,with minimal inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of 2.5 and 5.0 mg/mL,respectively.Also,the antibacterial effects of tPTNs were concentration-dependent.We observed a significant decrease in the absolute value of the zeta potential,and significant increases in particle size,cell membrane hydrophobicity,conductivity,the release of metal ions,and the leakage of nucleic acid as the concentration of tPTNs increased from 0 mg/mL to MBC.Furthermore,sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE)demonstrated that protein synthesis was inhibited or even disrupted.Analysis by liquid chromatography-mass spectrometry(LC-MS)indicated that treatment with tPTNs caused significant changes in bacterial metabolites,1117 and 692 differential metabolites being found for S.aureus and E.coli,respectively.The differential metabolites were involved in nucleotide metabolism,amino acid metabolism,tricarboxylic acid cycle and other metabolic pathways.These findings provide valuable insights for the application of thyme essential oil as an efficient antibacterial agent and for the understanding of its mechanism of action.
基金Project supported by the National Natural Science Foundation of China(No.32160108)the Science and Technology Special Fund of Hainan Province(No.ZDYF2024SHFZ116)+2 种基金the Specific Research Fund of the Innovation Center for Academicians of Hainan Province(No.YSPTZX202309)the Scientific Research Project of Hainan Higher Education Institutions(No.Hnky2022ZD-6)the Hainan Normal University National College Student Innovation Training Program(No.202411658006)。
文摘new heterocyclic dipeptide with a highly functionalized 1,2-oxazadecaline core,named trichodermamide H(1),and three known analogues,along with three known polyketides,were isolated from the fermentation extract of the mangrovederived fungus Penicillium janthinellum XLN32122.The structure of 1 was elucidated on the basis of extensive 1D and 2D NMR spectra data analysis,HR-ESI-MS,electronic circular dichroism(ECD)calculations.Trichodermamide B(3)exhibited better inhibitory effect on nitric oxide(NO)production in lipopolysaccharide(LPS)induced RAW 264.7 cells with an IC_(50)value of(13.13±0.005)μmol/L than that of the positive control dexamethasone[IC_(50)=(136.84±1.33)μmol/L].Compound 3 exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus(MRSA)with an IC_(50)value of 12.5μg/mL,while the positive control vancomycin showed an IC_(50)value of 1.563μg/mL.
文摘Chitosan(CTS)was grafted onto the surface of amino‑functionalized silver chloride silicon dioxide(AgCl@SiO_(2)‑NH_(2))cores to obtain AgCl@SiO_(2)/CTS hybrid nanoparticles.The as‑obtained AgCl@SiO_(2)/CTS nanoparticles were chlorinated by NaClO solution to get AgCl@SiO_(2)/CTS‑based chloramine nano‑hybrid materials,denoted as AgCl@SiO_(2)/CTS‑Cl.A transmission electron microscope was used to observe the morphology of the as‑prepared samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.At the same time,an X‑ray diffractometer and an infrared spectroscope were utilized to characterize their crystal and chemical structures.Besides,ζpotentials were measured to elucidate the surface modification of AgCl nanoparticles by—NH_(2),the antibacterial mechanism of AgCl@SiO_(2)/CTS‑Cl was investigated by scanning electron microscopy,and Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were used as the to‑be‑tested strains to evaluate the antimicrobial activity of samples AgCl@SiO_(2)/CTS and AgCl@SiO_(2)/CTS‑Cl.Findings demonstrate that sample AgCl@SiO_(2)/CTS exhibits a chain‑like structure ascribed to the interaction between—NH_(2),and each AgCl@SiO_(2)/CTS hybrid nanoparticle contains several AgCl cores.In the meantime,sample AgCl@SiO_(2)/CTS‑Cl exhibits excellent antibacterial activity against E.coli and S.aureus,which is attributed to the synergistic antibacterial effect of Ag^(+)and Cl^(-).Sample AgCl@SiO_(2)/CTS‑Cl with a dosage of 640.00μg·mL^(-1) could completely kill the two kinds of tested bacteria in 12 h of incubation;it retains a high antibacterial efficiency even after 10 cycles of antibacterial tests.
文摘Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.
基金supported by the National Natural Science Foundation of China(Nos.U213010103,22274131).
文摘Metal nanoclusters(MNCs),comprising several to hundreds of metal atoms,have attracted significant research interest owing to their distinctive physicochemical properties.Reticular frameworks(RFs)with ordered porous structures,including metalorganic frameworks(MOFs),covalent organic frameworks(COFs),hydrogen-bonded organic frameworks(HOFs),and supramolecular organic frameworks(SOFs),possess a variety of unique properties due to their high crystallinity,high porosity,large surface area,and adjustable structure.The integration of MNCs with RFs endows the resulting composites with desirable features(e.g.,enhanced and tunable optical properties,improved catalytic and photophysical activities,selective molecular recognition),which facilitates a broad spectrum of biomedical applications and advancing the development of integrated theranostic nanoplatforms.This review summarizes recent advances in the synthesis and biomedical applications of various MNCs/RFs composites.We systematically categorize and evaluate key strategies for incorporating MNCs into four types of RFs(MOFs,COFs,HOFs,and SOFs)while discussing the advantages and limitations of each approach.The biomedical applications of these composites are comprehensively reviewed,encompassing biosensing,bioimaging,antitumor therapy,and antibacterial treatments.Finally,the review addresses current challenges and outlines future research directions,with the aim of guiding the rational design of novel MNCs/RFs composites,enabling precise control over their structures and functions toward advanced biomedical applications.
文摘Plantago major L.,commonly known as plantain,waybread,or dooryard plantain,is a versatile medicinal plant with multiple therapeutic applications.Traditionally,various parts of the plant have been formulated into syrups,drops,ointments,vaginal suppositories,gargles,and roasted preparations to treat diverse ailments,such as liver disorders,earaches,epilepsy,asthma,stomachaches,diarrhea,constipation,polymenorrhea,and uterine disorders.The plant contains clinically valuable bioactive compounds,including polysaccharides,flavonoids,lipids,iridoid glycosides,caffeic acid derivatives,terpenoids,alkaloids,and organic acids.These bioactive constituents are the primary contributors to the plant’s broad spectrum of biological activities,including antioxidant,anti-inflammatory,antibacterial,antidiarrheal,hepatoprotective,antiviral,antiphage,antinociceptive,antiulcerogenic,antigenotoxic,and immunomodulatory effects of the plant.This review comprehensively summarizes the phytochemical composition,traditional medicinal applications,and biological properties of this multifunctional medicinal plant.
基金Funded by the National Natural Science Foundation of China(Nos.52278269,52278268,52178264)Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)。
文摘The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and ultra-depth microscope.The results show that the antibacterial adhesive can effectively inhibit the growth of sulfur-oxidizing bacteria in seawater,hinder their metabolism to produce biological sulfate,and reduce the formation of destructive product gypsum.The mineral composition and thermal analysis showed that the peak value of plaster diffraction peak and the mass loss of plaster dehydration in antibacterial adhesive group were significantly lower than those in blank group(without protective coating group).In addition,the electric flux of chloride ions(>400 C)in the blank group of mortar samples was higher than that in the antibacterial adhesive group(<200 C),indicating that the antibacterial adhesive can effectively reduce the permeability of chloride ions in mortar,and thus hinder the Cl-erosion in seawater.
基金supported by the National Natural Science Foundation of China(No.22431004)Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates(No.2023B1212060003)。
文摘Aggregation-induced emission(AIE)polymers have been extensively studied;however,the integration of AIE units into polyelectrolytes remains largely limited by the laborious multistep synthesis of pre-designed emissive monomers.Herein,we report a one-pot multicomponent polymerization method that directly produces main-chain charged polyelectrolytes with intrinsic AIE characteristics from non-emissive building blocks.By optimizing the monomer structures and reaction conditions,a series of soluble high-molecular-weight polymers with welldefined backbones were obtained in high yields.The resulting polyelectrolytes displayed robust AIE behavior,exhibiting fluorescence enhancement up to about 60-fold in an aqueous environment,and maintained excellent thermal stability.Owing to their cationic backbones,these polymers interact strongly with microbial surfaces and exhibit remarkable antimicrobial activities.This study establishes a synthetically efficient route to AIE polyelectrolytes and highlights their potential applications as multifunctional materials for bioimaging,antimicrobial therapy,and other applications.
基金supported by the National Natural Science Foundation of China(No.52173126)China Postdoctoral Science Foundation(No.2024M751152).
文摘Novel antibacterial strategies such as antibacterial photodynamic therapy(aPDT)and photothermal therapy(PTT)have gained significant attention,however,relying on a single-treatment approach still faces challenges of insufficient therapeutic efficiency and the potential for drug resistance.In this study,a multimodal synergistic antibacterial nanoplatform by coupling a carbon monoxide(CO)donor(4-(3-hydroxy-4-oxo-4H-chromen-2-yl)benzoic acid(4-BA))with carbon dots(CDs)is developed,referred to as CDs-CO,which integrates multiple antibacterial modes of aPDT,PTT,and gas therapy.This nanoplatform is designed for highly efficient antibacterial action with a low risk of inducing drug resistance.CDs are engineered to possess tailored functions,including deep-red light-triggered heat and singlet oxygen(^(1)O_(2))production.After modification with 4-BA and exposure to 660 nm laser irradiation,CDs-CO exhibits favorable photothermal conversion efficiency(η=52.7%),robust ^(1)O_(2) generation,and ^(1)O_(2)-activated CO release.Antibacterial experiments demonstrated the excellent sterilization effects of CDs-CO against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus),underscoring the enhanced antibacterial efficiency of this multimodal nanoplatform.This study offers a rational approach for designing multimodal synergistic antibacterial platforms,highlighting their potential for effectively treating bacterial infections.
基金The financial support from the National Natural Science Foundation of China (No.31972290)National Key Research and Development Program of China (No.2022YFD1700300)。
文摘Plant bacterial diseases cause significant harm to agricultural production because of their frequent,intermittent and regional outbreaks.Currently,chemical control is still a more effective method for bacterial disease.To develop new,efficient and safe antibacterial agrochemicals,we summarize the research progress of compounds with antibacterial activities in the past ten years,classify them according to their active skeletons,and discuss their structure-activity relationships and mechanisms of action.Finally,the development trend of antibacterial agrochemicals was prospected.This review provides valuable information for the development of antibacterial agrochemicals.
基金supported by the National Natural Science Foundation of China(No.82273919)Natural Science Foundation of Heilongjiang Province(No.LH2024H013)China Postdoctoral Science Foundation(No.2022MD723781).
文摘Constructing nanofibers with specific therapeutic effects against cancer is a challenge.Here,we present the synthesis approach and application prospects of supramolecular nanofibers,which are based on cucurbit[8]uril(CB[8])as the host and terpyridine lanthanum ions metal complex as the vip,constructed by layer-by-layer self-assembly through supramolecular interaction.Moreover,nanofibers with lanthanide luminescence properties exhibit surprising pH-responsive deformation properties and antibacterial behavior.In the tumor micro-environment,the dramatic reduction in the size of the nanofibers enables specific and hierarchical release of anticancer drugs in tumor cells to exert an advanced therapeutic effect.In addition,the synergistic therapeutic efficacy was achieved by reducing the excess of Gram-positive and Gram-negative bacteria surrounding tumor cells.The novel supramolecular nanofibers with sequential drug release and combined therapeutic mode provide new guidance for the synthesis of drug carrier materials and direction for the promotion of nanomaterial-mediated cancer therapy.
文摘The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.
基金Supported by Scientific Research Project of the Guangxi Zhuang Autonomous Region Administration of Traditional Chinese Medicine(GXZYA20220105).
文摘[Objectives]To evaluate the in vitro antibacterial,antioxidant,andα-glucosidase inhibitory activities of the ethanol total extract and four different polarity fractions(n-butanol,ethyl acetate,petroleum ether,and water)of Pilea peltata Hance,so as to provide a reference for its further development and research.[Methods]The antibacterial activity of P.peltata was evaluated in vitro by determining the minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of its ethanol total extract and four different polarity fractions against seven test bacterial strains using the broth microdilution method.The in vitro antioxidant activity was investigated through DPPH radical,hydroxyl radical,and superoxide anion radical scavenging assays,with vitamin C(Vit C)as the positive control and the half maximal scavenging concentration(IC 50)as the evaluation indicator.The in vitroα-glucosidase inhibitory activity was assessed by measuring the peak area of p-nitrophenol(PNP),the hydrolysis product of 4-nitrophenylα-D-glucopyranoside(PNPG),via high-performance liquid chromatography(HPLC),using the half maximal inhibitory concentration(IC_(50))as the evaluation indicator.[Results]Both the ethanol total extract and the four different polarity fractions of P.peltata exhibited significant in vitro anti-Streptococcus pneumoniae activity.The DPPH radical scavenging capacities of the ethanol total extract and the various fractions were all weaker than that of VitC,with the order of efficacy being:n-butanol fraction>ethanol total extract>ethyl acetate fraction>petroleum ether fraction>aqueous fraction.For hydroxyl radical scavenging activity,the efficacy order of P.peltata fractions was:n-butanol extract>ethyl acetate extract>ethanol total extract>petroleum ether extract>aqueous extract.Notably,the n-butanol fraction(IC_(50)=0.068±0.001)demonstrated stronger activity than VitC(IC_(50)=0.097±0.001).The activity of the ethyl acetate fraction(IC_(50)=0.096±0.004)was comparable to that of VitC(IC_(50)=0.097±0.001).The superoxide anion scavenging capacities of the ethanol total extract and different polarity fractions from P.peltata were all weaker than that of VitC,with the order of efficacy being:n-butanol fraction>ethyl acetate fraction>ethanol total extract>petroleum ether fraction>aqueous fraction.The ethanol total extract and aqueous fraction of Pilea peltata showed no significant in vitroα-glucosidase inhibitory activity.Compared with the acarbose group,the IC 50 values of the ethyl acetate fraction and the n-butanol fraction both showed highly significant differences(P<0.01).[Conclusions]This study provides an experimental basis for the pharmacodynamic study and active component study of P.peltata.
基金supported by the Guangdong Basic and Applied Basic Research Foundation,China(2024A1515012511 and 2022A1515012380)the Guangdong Special Project on Key Fields of Colleges and Universities,China(Rural Revitalization,2020ZDZX1020)+1 种基金the Science and Technology Special Fund Project of Maoming Science and Technology Bureau,China(2021KJZXZJGSPDX003)the Projects of Talents Rec r uitment of G uangdong Univer sit y of Petrochemical Technology,China(519033)。
文摘A microbial strain designated Bacillus licheniformis QX928 was screened from hot springs in Sichuan Province,China,and a compound generated in the culture of this strain clearly inhibited Pseudomonas aeruginosa ATCC27853.The measured minimum inhibitory and lowest bactericidal concentrations were(13±0.17)and(22±0.72)mg L^(-1),respectively.The compound was identified as 3-isopropylhexahydro-4H-pyrido[1,2-α]pyrazine-1,4(6H)-dione(IPHPPD).A Sci Finder search revealed that IPHPPD could be the first compound synthesized by microorganisms that had both antibacterial and anti-quorum sensing properties.At low concentrations,IPHPPD interfered with the signaling factors and population effects of P.aeruginosa,thereby altering the biofilm morphology and structure.IPHPPD more strongly inhibited P.aeruginosa at high concentrations,primarily by reducing its virulence factors,cell membrane permeability and energy metabolism.A transcriptome analysis highlighted the role of IPHPPD in the transcriptional regulation of cellular metabolism and quorum sensing.Thus,the results of this study provide critical evidence that IPHPPD is a potential target for drug development to prevent and treat diseases in animals.
基金support from the National Key Technologies R&D Program of China(2022YFE0114800)National Natural Science Foundation of China(22075047),and the 111 Project(D16008)。
文摘Hydrogen peroxide(H_(2)O_(2))is a versatile oxidant with significant applications,particularly in regulating the microenvironment for healthcare purposes.Herein,a rational design of the photoanode is implemented to enhance H_(2)O_(2) production by oxidizing H_(2)O in a portable photoelectrocatalysis(PEC)device.The obtained solution from this system is demonstrated for effective bactericidal activity against Staphylococcus aureus and Escherichia coli,while maintaining low toxicity toward hippocampal neuronal cells.The photoanode is achieved by Mo-doped BiVO4 films,which are subsequently loaded with cobalt-porphyrin(Co-py)molecules as a co-catalyst.As a result,the optimal performance for H_(2)O_(2) production rate was achieved at 8.4μmol h^(−1) cm^(−2),which is 1.8 times that of the pristine BiVO4 photoanode.Density functional theory(DFT)simulations reveal that the improved performance results from a 1.1 eV reduction in the energy of the rate-determining step of·OH adsorption by the optimal photoanode.This study demonstrates a PEC approach for promoting H_(2)O_(2) production by converting H_(2)O for antibacterial purposes,offering potential applications in conventionally controlling microenvironments for healthcare applications.
文摘Background: Mass drug administration(MDA)is a strategy to improve health at the population level through widespread delivery of medicine in a community.We surveyed the literature to summarize the benefits and potential risks associated with MDA of antibacterials,focusing predominantly on azithromycin as it has the greatest evidence base.Main body: High-quality evidence from randomized controlled trials(RCTs)indicate that MDA-azithromycin is effective in reducing the prevalence of infection due to yaws and trachoma.In addition,RCTs suggest that MDA-azithromycin reduces under-five mortality in certain low-resource settings that have high childhood mortality rates at baseline.This reduction in mortality appears to be sustained over time with twice-yearly MDA-azithromycin,with the greatest effect observed in children<1 year of age.In addition,observational data suggest that infections such as skin and soft tissue infections,rheumatic heart disease,acute respiratory illness,diarrheal illness,and malaria may all be treated by azithromycin and thus incidentally impacted by MDA-azithromycin.However,the mechanism by which MDA-azithromycin reduces childhood mortality remains unclear.Verbal autopsies performed in MDA-azithromycin childhood mortality studies have produced conflicting data and are underpowered to answer this question.In addition to benefits,there are several important risks associated with MDA-azithromycin.Direct adverse effects potentially resulting from MDA-azithromycin include gastrointestinal side effects,idiopathic hypertrophic pyloric stenosis,cardiovascular side effects,and increase in chronic diseases such as asthma and obesity.Antibacterial resistance is also a risk associated with MDA-azithromycin and has been reported for both gram-positive and enteric organisms.Further,there is the risk for cross-resistance with other antibacterial agents,especially clindamycin.Conclusions: Evidence shows that MDA-azithromycin programs may be beneficial for reducing trachoma,yaws,and mortality in children<5 years of age in certain under-resourced settings.However,there are significant potential risks that need to be considered when deciding how,when,and where to implement these programs.Robust systems to monitor benefits as well as adverse effects and antibacterial resistance are warranted in communities where MDA-azithromycin programs are implemented.
基金financially supported by the National Natural Science Foundation of China(No.52203209)the State Key Laboratory of Solid Waste Reuse for Building Materials,China(No.SWR-2022-009)the Fundamental Research Funds for the Central Universities,China(No.FRF-IDRY22-012)。
文摘Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial property.However,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water pollution.In this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing agent.Experimental analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag NPs.The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation.After the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite hydrogel.The inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag NPs.The prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.
基金supported by the National Natural Science Foundation of China(No.52001034)the China Postdoctoral Science Foundation(No.2023M731677)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_3032).
文摘Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte.The influence of varying ZnO concentrations on the microstructure,corrosion resistance,and antibacterial properties of the coating was examined through microstructure analysis,immersion tests,electrochemical experiments,and antibacterial assays.The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy.Specifically,when the ZnO concentration in the electrolyte was 5 g/L,the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO.Moreover,the antibacterial efficacy of ZnO+MAO coating,prepared with a ZnO concentration of 5 g/L,surpassed 95%after 24 h of co-culturing with Staphylococcus aureus(S.aureus).The nano-ZnO+MAO-coated alloy exhibited exceptional degradation resistance,corrosion resistance,and antibacterial effectiveness.
