[ Objective ] The paper was to screen the effective agents against kiwifruit bacterial canker in Wanzhou District of China. [ Method ] Ten kinds of com- mon commercial bactericides preliminarily screened were selected...[ Objective ] The paper was to screen the effective agents against kiwifruit bacterial canker in Wanzhou District of China. [ Method ] Ten kinds of com- mon commercial bactericides preliminarily screened were selected for indoor antibacterial test using paper plate method and plate streaking method, and six kinds of bactericides with good antibacterial effects were further screened for indoor toxicity test. [ Result] Chloramphenicoloethylicin had the best antibacterial effect, with EC50 of 36.34 rag/L; followed by Xintianxlucai No. 6 and embamycin, with EC50 of 83.21 and 92.34 mg/L, respectively. [ Conclusion] Cldoramphenicoloethylicin, Xintianxiucai No. 6 and embamycin screened in the test had good antibacterial effect against kiwifruit bacteriai canker in Wanzhou District, and chlorampheni- coleethylicin was the most effective agent. These three agents could be directly applied to control kiwifruit bacterial canker in production, while application time and climate conditions in fields should also be considered during the actual application process. It is suggested that three agents can be used alternatively in order to de- lay the resistance of plants.展开更多
Superhydrophobic surface is a promising strategy for antibacterial and corrosion protection.However,the use of harmful fluorine-containing materials,poor mechano-chemical stability,the addition of fungicides and poor ...Superhydrophobic surface is a promising strategy for antibacterial and corrosion protection.However,the use of harmful fluorine-containing materials,poor mechano-chemical stability,the addition of fungicides and poor corrosion resistance often limit its practical application.In this paper,a high-robustness pho-tothermal self-healing superhydrophobic coating is prepared by simply spraying a mixture of hydropho-bically modified epoxy resin and two kinds of modified nanofillers(carbon nanotubes and SiO2)for long-term anticorrosion and antibacterial applications.Multi-scale network and lubrication structures formed by cross-linking of modified carbon nanotubes and repeatable roughness endow coating with high ro-bustness,so that the coating maintains superhydrophobicity even after 100 Taber abrasion cycles,20 m sandpaper abrasion and 100 tape peeling cycles.The synergistic effect of antibacterial adhesion and pho-tothermal bactericidal activity endows coating with excellent antibacterial efficiency,which against Es-cherichia coli(E.coli)and Staphylococcus aureus(S.aureus)separately reaches 99.6% and 99.8%.Moreover,the influence of modified epoxy resin,superhydrophobicity,organic coating and coating thicknesses on the anticorrosion of magnesium(Mg)alloy is systematically studied and analyzed.More importantly,the prepared coating still exhibits excellent self-cleaning,anticorrosion and antibacterial abilities after 20 m abrasion.Furthermore,the coating exhibits excellent adhesion(level 4B),chemical stability,UV radiation resistance,high-low temperature alternation resistance,stable heat production capacity and photother-mal self-healing ability.All these excellent performances can promote its application in a wider range of fields.展开更多
Planktonic bacteria adhere and subsequently form biofilms on implantable medical devices can cause severe infections that have become the major types of hospital-acquired infections.Traditional coatings for the implan...Planktonic bacteria adhere and subsequently form biofilms on implantable medical devices can cause severe infections that have become the major types of hospital-acquired infections.Traditional coatings for the implants are frequently lack of long-term antifouling and bactericidal activities.It is still a big challenge to simultaneously improve the antifouling and bactericidal activities of the coatings.Herein,we report that mixed-charge glycopolypeptide coatings are of long-term antibacterial activities to efficiently inhibit the biofilm growth.The glycosylation of mixed-charge polypeptides has led to a significant improvement of both antifouling and bactericidal activities.The cooperative effect of the saccharide residues and mixed-charge residues improved the resistance of the polypeptide coatings against protein adsorption.The saccharide and L-glutamic acid(E)residues collectively enhanced the bacterial membrane-disruption of cationic L-lysine(K)residues,leading to potent bactericidal activity.Meanwhile,the glycopolypeptide coatings showed superior biocompatibility,long-term antibiofilm and anti-infection properties in two types of mouse subcutaneous infection models and one type of mouse urinary tract infection model.This work provides a new strategy to achieve antibacterial coatings with long-term activities for preventing implantable medical device associated infections.展开更多
This study investigates the effect of apple extract on CoFe_(2)O_(4) nanoparticles synthesized via a green self-ignition method.High resolution transmission electron microscope(HRTEM)showed nanometric particles with v...This study investigates the effect of apple extract on CoFe_(2)O_(4) nanoparticles synthesized via a green self-ignition method.High resolution transmission electron microscope(HRTEM)showed nanometric particles with varied shapes,while X-ray diffraction(XRD)and Rietveld refinement confirmed a facecentered cubic(Fd3m)structure.Mössbauer spectroscopy revealed a Zeeman sextet pattern with only Fe^(3+) ions.Ultra violet vissible nearinfrared(UV-Vis-NIR)spectra indicated strong absorbance in the visible and NIR regions,suggesting optoelectronic potential.The nanoparticles demonstrated high photo-Fenton catalytic efficiency,degrading 96.88%of Methylene Blue under visible light.They also exhibited 100%adsorption capacities for Cr^(3+) and Pb^(2+),making them effective for water treatment.These properties were attributed to a large surface area(347.04 m2/g),mesoporous structure,and mixed spinel phase.ANOVA and Tukey’s honestly significant difference(HSD)tests confirmed that contact time and adsorbent dosage significantly affected pollutant removal.Additionally,strong antimicrobial activity highlighted their biotechnological relevance.The inclusion of apple extract enhanced structural and functional features,expanding application prospects in spin valves,magnetic recording,refrigeration,microwave technologies(C to Ku bands),optoelectronics,and biotechnology.Future work should explore the photo-Fenton degradation mechanism and optimize synthesis for scalable production,aiming to maximize their industrial utility.展开更多
The determination of 7 bactericidals residues,including chlorthalonil,dichlofluanid,tolylfluanid,captan,folpet,captafol and deltamethrin,in foods by using on-line gel permeation chromatography(GPC) coupled with gas ch...The determination of 7 bactericidals residues,including chlorthalonil,dichlofluanid,tolylfluanid,captan,folpet,captafol and deltamethrin,in foods by using on-line gel permeation chromatography(GPC) coupled with gas chromatography-mass spectrometry(GC-MS).Bactericidal residues were extracted with acetonitrile,and cleaned up by ENVI-Crab,LC-NH2 column and GPC,respectively.The analysis of 7 bactericidals residues was performed by GC-MS.The average recoveries of analytes were range of 75%-120% with RSD of 3.5%-10.3%.展开更多
By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy o...By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt) were determined. The results of the test show that the electroplated deposits of zinc, cobalt, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt, silver and copper possess a distinct antibacterial capability against the growth of pathogenic bacteria tested, and that SUS304 stainless steel and chromium deposit have no antibacterial activity. The relationship between the antibacterial capability and the rest potentials of the deposits was investigated. It was found that the higher the antibacterial activity of the electroplated deposit was, the more negative the rest potential of deposit was.展开更多
This work is a result of previously done studies on the synthesis of A2FeVIO4 wet ferrate (VI) formula, using chlorine as an oxidant. The major problem of these ferrates is related to their stability over time. This b...This work is a result of previously done studies on the synthesis of A2FeVIO4 wet ferrate (VI) formula, using chlorine as an oxidant. The major problem of these ferrates is related to their stability over time. This brings us to identify and optimize the critical parameters influencing the preparation of the Na2FeO4 at room stable phase with acceptable performance. The use of water bleach (hypochlorite ClO‾) at a chlorometric degree of 50°F in the synthesis of the Na2FeO4 ambient stable phase promotes the oxidation of iron (II) iron to (VI) in a concentrated NaOH alkaline medium. The synthesis reaction is in the presence of FeSO4 7H2O hydrated iron sulfate at a temperature of about 55°C in order to simplify the synthesis process, to enhance the production of the Fe (VI) and to meet the growing demand of ferrates (VI) for their interest in the treatment of water. Monitoring the degradation of synthesized Na2FeO4 shows its stability up to 12 months, which facilitates storage and transportation. The phases obtained were characterized by IR spectroscopy, and RX by UV spectrophotometer, measuring the optical density at 507 nm.展开更多
The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based ...The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based cutting fluid accounts for more than 90%of the consumption of cutting fluid.However,long-term recycling of water-based cutting fluid could easily cause deterioration,and the breeding of bacteria could cause the cutting fluid to fail,increase manufacturing costs,and even endanger the health of workers.Traditional bactericides could improve the biological stability of cutting fluids,but they are toxic to the environment and do not conform to the development trend of low-carbon manufacturing.Low-carbon manufacturing is inevitable and the direction of sustainable manufacturing.The use of nanomaterials,transition metal complexes,and physical sterilization methods on the bacterial cell membrane and genetic material could effectively solve this problem.In this article,the mechanism of action of additives and microbial metabolites was first analyzed.Then,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were summarized.Further,the mechanism of nanomaterials disrupting cell membrane potential was discussed.The effects of lipophilicity and the atomic number of transition metal complexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were reviewed.In other words,the bactericidal performance,hazard,degradability,and economics of various sterilization methods were comprehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.展开更多
Objective:To ascertain the potential antibacterial activity of honey against clinical isolates of Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Salmonella enterica serovar Typhi(S.enterica serovar ...Objective:To ascertain the potential antibacterial activity of honey against clinical isolates of Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Salmonella enterica serovar Typhi(S.enterica serovar Typhi) by in vitro methods.Methods:The partial inhibitory concentration(PIC),minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) values of the autoclaved honey(extracted from Apis indica hive by indigenous method) were determined for S.enterica serovar Typhi(n=8:from blood cultute), E.coli(n=5:from urine culture) and P.aeruginosa(n=5:from pus culture) isolates by in vitro methods.Results:The PICs of the honey tested for the isolates ranged 0.50%-1.25%(v/v) for S. enterica serovar Typhi,0.75%-1.50%(v/v) for E.coli and 1.00%-1.25%(v/v) for P.aeruginosa, while the MICs ranged 1.75%-3.00%(v/v),3.00%-3.50%(v/v) and 3.50%(v/v),respectively.The P.aeruginosa and E.coli isolates had MBC value of 4.00%(v/v):the S.enterica serovar Typhi showed MBCs in between 3.00%and 3.50%(v/v).The bactericidal activity of honey was achieved at concentration 3.00%(v/v) for S.enterica serovar Typhi and E.coli,and at 3.50%(v/v) for P. aeruginosa.Conclusions:The excellent antibacterial activity of honey against clinical bacterial isolates indicates the usefulness of honey in clinical practice against bacterial infection.展开更多
AIM: To investigate the bactericidal effects of Chenopodium ambrosioides L.(CAL) against Helicobacter pylori(H.pylori) both in vitro and in vivo.METHODS: For in vitro experiments, the inhibitory activity of CAL was te...AIM: To investigate the bactericidal effects of Chenopodium ambrosioides L.(CAL) against Helicobacter pylori(H.pylori) both in vitro and in vivo.METHODS: For in vitro experiments, the inhibitory activity of CAL was tested using an agar dilution method; H.pylori strain NCTC11637 was incubated on Columbia blood agar plates containing serial concentrations of CAL.The minimal inhibitory concentration(MIC) was determined by the absence of H.pylori colonies on the agar plate.Time-kill curves were used to evaluate bactericidal activity; the average number of colonies was calculated at 0, 2, 8 and 24 h after liquid incubation with concentrations of CAL at 0.5, 1, and 2 × MIC.For in vivo experiments, H.pylori-infected mice were randomly divided into CAL, triple therapy(lansoprazole, metronidazole, and clarithromycin), blank control, or H.pylori control groups.The eradication ratios were determined by positive findings from rapid urease tests(RUTs) and by histopathology.RESULTS: In vitro, the MIC of CAL against H.pylori was 16 mg/L.The time-kill curves showed a stable and persistent decreasing tendency with increasing CAL concentration, and the intensity of the bactericidal effect was proportional to dose; the 1 and 2 × MIC completely inhibited the growth of H.pylori at 24 h.In vivo, the eradication ratios in the CAL group were60%(6/10) by RUT and 50%(5/10) by histopathology.Ratios in the triple therapy group were both 70%(7/10), and there was no difference between the CAL and triple therapy groups.Histopathologic evaluation revealed massive bacterial colonization on the surface of gastric mucosa and slight infiltration of mononuclear cells after inoculation with H.pylori, but no obvious inflammation or other pathologic changes in gastric mucosa of mice from CAL and triple therapy groups.CONCLUSION: CAL demonstrates effective bactericidal activity against H.pylori both in vitro and in vivo.展开更多
Superhydrophobic surfaces with water-repelling ability have important applications, such as self-cleaning, antibacterial and corrosion protection. However, the using of harmful fluorinated materials and its poor mecha...Superhydrophobic surfaces with water-repelling ability have important applications, such as self-cleaning, antibacterial and corrosion protection. However, the using of harmful fluorinated materials and its poor mechanochemical stability limit its practical application. Herein, a fluorine-free, robust and self-healing superhydrophobic surface is prepared through a two-step method of laser processing and spraying coating for anticorrosion and antibacterial applications. Laser processing is used to construct periodic micron-sized pillars for obtaining strong interface bonding between coating and substrate by mechanical interlocking effect, and as an ‘armor’, preventing the removal of the coating. The coating consists of epoxy resin (EP), hexadecyltrimethoxysilane (HDTMS) and γ-aminopropyltriethoxysilane treated Cu2O (KH550-Cu2O). The superhydrophobic surface can withstand various mechanical durability tests, such as multiple sandpaper abrasion and tape peeling cycles. It exhibits excellent corrosion inhibition efficiency (ηp > 99 %) on Mg alloy, Tinplate and Al alloy, which results from superhydrophobicity and organic coating. The superhydrophobicity endows surface with excellent antibacterial adhesion performance in a static liquid environment. The bactericidal activity of KH550-Cu2O can effectively inactivate the bacteria in contact with the surface and the free bacteria, providing excellent antibacterial ability in a dynamic liquid environment. It still exhibits good anticorrosion and antibacterial abilities after multiple mechanical abrasion cycles due to the outstanding mechanical durability. Moreover, it exhibits outstanding self-healing ability to plasma etching and oil contamination, self-cleaning ability under air and oil conditions, and chemical stability against acids and alkalis solution. All the above excellent performances promote its application in a wider range of fields.展开更多
Attachment of bacteria and subsequent formation of biofilms on material surfaces lead to serious consequences including infection,contamination and biofouling,posing a prominent threat to human health and causing prob...Attachment of bacteria and subsequent formation of biofilms on material surfaces lead to serious consequences including infection,contamination and biofouling,posing a prominent threat to human health and causing problems in many industries.Therefore,it is highly desirable to endow the surfaces with antibacterial properties.Traditional antibacterial surfaces are designed via either bacteria-resisting strategy to prevent the initial adhesion of bacteria or bacteria-killing strategy to eradicate any bacteria that attach to the surface.However,these single-function surfaces have their inherent shortcomings and cannot realize long-term efficacy against bacteria.In recent years,various dual-function antibacterial surfaces with both bacteria-resisting and bacteria-killing properties together have been developed,showing better performance for combating surface-attached bacteria and preventing formation of biofilms.In this review,we summarize the recent development of these dual-function antibacterial surfaces.We focus on the design principles and fabrication strategies of such surfaces and highlight the representative examples,which are categorized specifically into two types according to the anti-adhesive and bactericidal properties are simultaneous or switchable.A brief perspective is finally presented on current challenges and future research directions.展开更多
It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties...It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.展开更多
Objective:To investigate the synergic antibacterial activity of garlic and tazma honey against standard and clinical pathogenic bacteria.Methods:Antimicrobial activity of tazma honey,garlic and mixture of them against...Objective:To investigate the synergic antibacterial activity of garlic and tazma honey against standard and clinical pathogenic bacteria.Methods:Antimicrobial activity of tazma honey,garlic and mixture of them against pathogenic bacteria were determined.Chloramphenicol and water were used as positive and negative controls,respectively.Minimum inhibitory concentration(MIC)and minimum bactericidal concentration of antimicrobial samples were determined using standard methods.Results:Inhibition zone of mixture of garlic and tazma honey against all tested pathogens was significantly(P≤0.05)greater than garlic and tazma honey alone.The diameter zone of inhibition ranged from(18±1)to(35±1)mm for mixture of garlic and tazma honey,(12±1)to(20±1)nun for tazma honey and(14±1)to(22±1)mm for garlic as compared with(10±1)to(30±1)mm for chloramphenicol.The combination of garlic and tazma honey(30-35 mm)was more significantly(P≤0.05)effective against Salmonella(NCTC 8385),Staphylococcus aureus(ATCC 25923),Lyesria moncytogenes(ATCC 19116)and Streptococcus pneumonia(ATCC 63).Results also showed considerable antimicrobial activity of garlic and tazma honey.MIC of mixture of garlic and tazma honey at 6.25%against total test bacteria was 88.9%.MIC of mixture of garlic and tazma honey at6.25%against Gram positive and negative were 100%and 83.33%,respectively.The bactericidal activities of garlic,tazma honey,and mixture of garlic and tazma honey against all pathogenic bacteria at 6.25%concentration were 66.6%,55.6%and 55.6%,respectively.Conclusions:This finding strongly supports the claim of the local community to use the combination of tazma honey and garlic for the treatment of different pathogenic bacterial infections.Therefore,garlic in combination with tazma honey can serve as an alternative natural antimicrobial drug for the treatment of pathogenic bacterial infections.Further in vivo study is recommended to come up with a comprehensive conclusion.展开更多
Objective:To evaluate antibacterial activity of hot and cold ethanol and methanol leaf extracts of Ricinus communis L(R.communis)against Staphylococcus aureus(S.aureus)(NCTC 6571)and Escherichia coli(E.coli)(ATCC 2592...Objective:To evaluate antibacterial activity of hot and cold ethanol and methanol leaf extracts of Ricinus communis L(R.communis)against Staphylococcus aureus(S.aureus)(NCTC 6571)and Escherichia coli(E.coli)(ATCC 25922).Methods:Leaf powder of R.communis L.was extracted with hot(in Soxhlet)and cold ethanol and methanol,separately.The antibacterial activity of the extracts was determined by agar well diffusion and macro broth dilution methods.The extracts were also subjected to phytochemical analysis.Results:All the four test extracts showed inhibition on both S.aureus and E.coli.Hot and cold ethanol extracts revealed significantly(P<0.05)higher inhibition on S.aureus than methanol extracts,and the hot ethanol extract had the lowest minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)values(5 mg/mL and 10 mg/mL,respectively).E.coli was highly inhibited by hot extracts of both ethanol and methanol with the MIC and MBC of 40 mg/mL and 80 mg/mL,respectively.Phytochemical analysis revealed the presence of saponins,cardiac glycosides,tannins,flavonoids and terpenoids in all test extracts.Conclusions:This study demonstrates that the hot and cold methanol and ethanol extracts are potential sources for control of S.aureus and E.coli.Especially,the hot and cold extracts of ethanol are more inhibitive against 5.aureus even at lower concentration.Further study is needed to identify the specific bioactive compounds,their mode of action and their nontoxic nature in vivo condition.展开更多
Bacterial biofilm infections have been threatening the human’s life and health globally for a long time because they typically cause chronic and persistent infections.Traditional antibiotic therapies can hardly eradi...Bacterial biofilm infections have been threatening the human’s life and health globally for a long time because they typically cause chronic and persistent infections.Traditional antibiotic therapies can hardly eradicate biofilms in many cases,as biofilms always form a robust fortress for pathogens inside,inhibiting the penetration of drugs.To address the issues,many novel drug carriers emerged as promising strategies for biofilm treatment.Among them,stimuli-responsive nanocarriers have attracted much attentions for their intriguing physicochemical properties,such as tunable size,shape and surface chemistry,especially smart drug release characteristic.Based on the microenvironmental difference between biofilm infection sites and normal tissue,many stimuli,such as bacterial products accumulating in biofilms(enzymes,glutathione,etc.),lower pH and higher H_(2)O_(2)levels,have been employed and proved in favor of“on-demand”drug release for biofilm elimination.Additionally,external stimuli including light,heat,microwave and magnetic fields are also able to control the drug releasing behavior artificially.In this review,we summarized recent advances in stimuli-responsive nanocarriers for combating biofilm infections,and mainly,focusing on the different stimuli that trigger the drug release.展开更多
In this paper,the influences of gas doping(O2,N2,Air)on the concentrations of reactive species and bactericidal effects induced by a He plasma jet are studied.Firstly,results show that gas doping causes an increase in...In this paper,the influences of gas doping(O2,N2,Air)on the concentrations of reactive species and bactericidal effects induced by a He plasma jet are studied.Firstly,results show that gas doping causes an increase in voltage and a decrease in current compared with the pure He discharge under the same discharge power,which might be attributed to the different chemical characteristics of O2 and N2 and verified by the changes in the gaseous reactive species shown in the optical emission spectroscopy(OES)and Fourier transform infrared(FTIR)spectroscopy.Secondly,the concentrations of aqueous reactive oxygen species(ROS)and reactive nitrogen species(RNS)are tightly related to the addition of O2 and N2 into the working gas.The concentrations of aqueous NO-2 and NO-3 significantly increase while the concentrations of aqueous ROS decrease with the admixture of N2.The addition of O2 has little effect on the concentrations of NO-2 and NO-3 and pH values;however,the addition of O2 increases the concentration of O-2 and deceases the concentrations of H2O2 and OH.Finally,the results of bactericidal experiments demonstrate that the inactivation efficiency of the four types of plasma jets is He+O2>He+Air>He>He+N2,which is in accordance with the changing trend of the concentration of aqueous O.-2 Simultaneously to the better understanding of the formation and removal mechanisms of reactive species in the plasma–liquid interaction,these results also prove the effectiveness of regulating the concentrations of aqueous reactive species and the bacteria inactivation effects by gas doping.展开更多
To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cu...To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cup plate diffusion method. Results: The ethanol extract of the plant showed antibacterial activity against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Slaphylococcus aureus (S. aureus) , Salmonella sp. , Pseudomonas aeruginosa and Neisseria gonor-r/iaeae, while the water extract was active against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Sta-phylococcus aureus and. Pseudomonas aeruginosa. The etlianol extract exhibited higher antibacterial activity than the water extract. The minimum inhibitory concentration (MIC) and minimum bactericidal, concentration (MBC} of the ethanol extract were 0. 65 mg/mt and 0. 85 mg/ml, respectively , against S. aureus. Treatment of the extract at higher temperature, 60℃ increased the sensitivity of the test organisms to the plant extract. Phytochemical analysis indicated t/tat the plant possesses tannins, saponins as well as phenols. Conclusion: A scientific basis exists that the plant possesses antibacterial activity and it could be a probable source of therapeutic agent.展开更多
Bacterial infections associated with biomedical devices and implants have posed a great challenge to global healthcare systems.These infections are mainly caused by bacterial biofilm formed on the surface of biomateri...Bacterial infections associated with biomedical devices and implants have posed a great challenge to global healthcare systems.These infections are mainly caused by bacterial biofilm formed on the surface of biomaterials,protecting the encapsulated bacteria from conventional antibiotic treatment and attack of the immune system.As the bacterial biofilm is difficult to eradicate,bactericidal and antifouling coatings have emerged as promising strategies to prevent biofilm fo rmation and subsequent infections.Hydrogels with three-dimensional crosslinked hydrophilic networks,tunable mechanical property and large drugloading capacity are desirable coating materials,which can kill bacteria and/or prevent bacterial adhesion on the surface,inhibiting biofilm formation.Herein,we review recent developments of hydrogels as anti-infective coatings.Particularly,we highlight two chemical approaches(graft-from and graft-to),which have been used to immobilize hydrogels on surfaces,and present advances in the development of bactericidal(contact-killing and antimicrobial-releasing),antifouling(hydrophilic polymer network)and bifunctional hydrogel coatings with both bactericidal and antifouling activities.In addition,the challe nges of hydrogel coatings for clinical applications are discussed,and future research directions of anti-infective hydrogel coatings are proposed.展开更多
Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as th...Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as the recovery of viscous spilled crude oil,bacteria-containing oily wastewater,and removal of spilled oil under fire),and the autorecycling of oil and absorption materials remain a great challenge.This work proposed an ingenious design strategy of“several birds with one stone”to prepare p H/thermoresponsive flame-retardant/photothermal bactericidal P-Fe_(3)O_(4)-polydopamine(PDA)@melamine–formaldehyde(MF)foams.This design makes the foams remarkably effective in the recovery of spilled viscous crude oil as well as in the separation of bacteria-containing oily emulsions,particularly for instant fire extinguishing by magnetically controlled oil absorption as well as for fire alarms.The photothermal effect and p H response induce a change in the surface wettability of the foams,facilitating excellent autoadsorption/desorption of the spilled oil.The photothermal bactericidal activity and fouling resistance of the foam are beneficial to the separation of bacteria-containing oily wastewater.Outstanding flame-retardant properties and maneuverable magnetic control enable the foam to rapidly recover the spilled oil in a large range of fires,extinguish fires instantly,and facilitate early fire warning.The proposed strategy is expected to inspire further research on treating oil spills under complex conditions.展开更多
基金Supported by Application Development Research Project of Chongqing Municipal Commission of Science and Technology in 2014 "Occurrence Regularity and Integrated Key Control Technologies of Kiwifruit Bacterial Canker"(cstc2014yykfA8011)
文摘[ Objective ] The paper was to screen the effective agents against kiwifruit bacterial canker in Wanzhou District of China. [ Method ] Ten kinds of com- mon commercial bactericides preliminarily screened were selected for indoor antibacterial test using paper plate method and plate streaking method, and six kinds of bactericides with good antibacterial effects were further screened for indoor toxicity test. [ Result] Chloramphenicoloethylicin had the best antibacterial effect, with EC50 of 36.34 rag/L; followed by Xintianxlucai No. 6 and embamycin, with EC50 of 83.21 and 92.34 mg/L, respectively. [ Conclusion] Cldoramphenicoloethylicin, Xintianxiucai No. 6 and embamycin screened in the test had good antibacterial effect against kiwifruit bacteriai canker in Wanzhou District, and chlorampheni- coleethylicin was the most effective agent. These three agents could be directly applied to control kiwifruit bacterial canker in production, while application time and climate conditions in fields should also be considered during the actual application process. It is suggested that three agents can be used alternatively in order to de- lay the resistance of plants.
基金the National Natural Science Foundation of China(Nos.U2106226,52105297)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)the Science and Technology Development Project of Jilin Province(Nos.20210203022SF,20210508029RQ).
文摘Superhydrophobic surface is a promising strategy for antibacterial and corrosion protection.However,the use of harmful fluorine-containing materials,poor mechano-chemical stability,the addition of fungicides and poor corrosion resistance often limit its practical application.In this paper,a high-robustness pho-tothermal self-healing superhydrophobic coating is prepared by simply spraying a mixture of hydropho-bically modified epoxy resin and two kinds of modified nanofillers(carbon nanotubes and SiO2)for long-term anticorrosion and antibacterial applications.Multi-scale network and lubrication structures formed by cross-linking of modified carbon nanotubes and repeatable roughness endow coating with high ro-bustness,so that the coating maintains superhydrophobicity even after 100 Taber abrasion cycles,20 m sandpaper abrasion and 100 tape peeling cycles.The synergistic effect of antibacterial adhesion and pho-tothermal bactericidal activity endows coating with excellent antibacterial efficiency,which against Es-cherichia coli(E.coli)and Staphylococcus aureus(S.aureus)separately reaches 99.6% and 99.8%.Moreover,the influence of modified epoxy resin,superhydrophobicity,organic coating and coating thicknesses on the anticorrosion of magnesium(Mg)alloy is systematically studied and analyzed.More importantly,the prepared coating still exhibits excellent self-cleaning,anticorrosion and antibacterial abilities after 20 m abrasion.Furthermore,the coating exhibits excellent adhesion(level 4B),chemical stability,UV radiation resistance,high-low temperature alternation resistance,stable heat production capacity and photother-mal self-healing ability.All these excellent performances can promote its application in a wider range of fields.
基金the financial support from the National Natural Science Foundation of China(No.51873213)Science and Technology Program of Suzhou(No.SKY2022111)Collaborative Innovation Center of Suzhou Nano Science&Technology,and FUNSOM Self-Directed Research Project(No.2022)。
文摘Planktonic bacteria adhere and subsequently form biofilms on implantable medical devices can cause severe infections that have become the major types of hospital-acquired infections.Traditional coatings for the implants are frequently lack of long-term antifouling and bactericidal activities.It is still a big challenge to simultaneously improve the antifouling and bactericidal activities of the coatings.Herein,we report that mixed-charge glycopolypeptide coatings are of long-term antibacterial activities to efficiently inhibit the biofilm growth.The glycosylation of mixed-charge polypeptides has led to a significant improvement of both antifouling and bactericidal activities.The cooperative effect of the saccharide residues and mixed-charge residues improved the resistance of the polypeptide coatings against protein adsorption.The saccharide and L-glutamic acid(E)residues collectively enhanced the bacterial membrane-disruption of cationic L-lysine(K)residues,leading to potent bactericidal activity.Meanwhile,the glycopolypeptide coatings showed superior biocompatibility,long-term antibiofilm and anti-infection properties in two types of mouse subcutaneous infection models and one type of mouse urinary tract infection model.This work provides a new strategy to achieve antibacterial coatings with long-term activities for preventing implantable medical device associated infections.
文摘This study investigates the effect of apple extract on CoFe_(2)O_(4) nanoparticles synthesized via a green self-ignition method.High resolution transmission electron microscope(HRTEM)showed nanometric particles with varied shapes,while X-ray diffraction(XRD)and Rietveld refinement confirmed a facecentered cubic(Fd3m)structure.Mössbauer spectroscopy revealed a Zeeman sextet pattern with only Fe^(3+) ions.Ultra violet vissible nearinfrared(UV-Vis-NIR)spectra indicated strong absorbance in the visible and NIR regions,suggesting optoelectronic potential.The nanoparticles demonstrated high photo-Fenton catalytic efficiency,degrading 96.88%of Methylene Blue under visible light.They also exhibited 100%adsorption capacities for Cr^(3+) and Pb^(2+),making them effective for water treatment.These properties were attributed to a large surface area(347.04 m2/g),mesoporous structure,and mixed spinel phase.ANOVA and Tukey’s honestly significant difference(HSD)tests confirmed that contact time and adsorbent dosage significantly affected pollutant removal.Additionally,strong antimicrobial activity highlighted their biotechnological relevance.The inclusion of apple extract enhanced structural and functional features,expanding application prospects in spin valves,magnetic recording,refrigeration,microwave technologies(C to Ku bands),optoelectronics,and biotechnology.Future work should explore the photo-Fenton degradation mechanism and optimize synthesis for scalable production,aiming to maximize their industrial utility.
文摘The determination of 7 bactericidals residues,including chlorthalonil,dichlofluanid,tolylfluanid,captan,folpet,captafol and deltamethrin,in foods by using on-line gel permeation chromatography(GPC) coupled with gas chromatography-mass spectrometry(GC-MS).Bactericidal residues were extracted with acetonitrile,and cleaned up by ENVI-Crab,LC-NH2 column and GPC,respectively.The analysis of 7 bactericidals residues was performed by GC-MS.The average recoveries of analytes were range of 75%-120% with RSD of 3.5%-10.3%.
文摘By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt) were determined. The results of the test show that the electroplated deposits of zinc, cobalt, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt, silver and copper possess a distinct antibacterial capability against the growth of pathogenic bacteria tested, and that SUS304 stainless steel and chromium deposit have no antibacterial activity. The relationship between the antibacterial capability and the rest potentials of the deposits was investigated. It was found that the higher the antibacterial activity of the electroplated deposit was, the more negative the rest potential of deposit was.
文摘This work is a result of previously done studies on the synthesis of A2FeVIO4 wet ferrate (VI) formula, using chlorine as an oxidant. The major problem of these ferrates is related to their stability over time. This brings us to identify and optimize the critical parameters influencing the preparation of the Na2FeO4 at room stable phase with acceptable performance. The use of water bleach (hypochlorite ClO‾) at a chlorometric degree of 50°F in the synthesis of the Na2FeO4 ambient stable phase promotes the oxidation of iron (II) iron to (VI) in a concentrated NaOH alkaline medium. The synthesis reaction is in the presence of FeSO4 7H2O hydrated iron sulfate at a temperature of about 55°C in order to simplify the synthesis process, to enhance the production of the Fe (VI) and to meet the growing demand of ferrates (VI) for their interest in the treatment of water. Monitoring the degradation of synthesized Na2FeO4 shows its stability up to 12 months, which facilitates storage and transportation. The phases obtained were characterized by IR spectroscopy, and RX by UV spectrophotometer, measuring the optical density at 507 nm.
基金Supported by National Key Research and Development Program of China(Grant No.2020YFB2010500)National Natural Science Foundation of China(Grant Nos.51975305,51905289)+2 种基金Shandong Provincial Major Science and Technology Innovation Engineering Projects of China(Grant No.2019JZZY020111)Shandong Provincial Natural Science Foundation of China(Grant Nos.ZR2020KE027,ZR2020ME158,ZR2019PEE008)Applied Basic Research Youth Project of Qingdao Science and Technology Plan(Grant No.19-6-2-63-cg)。
文摘The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based cutting fluid accounts for more than 90%of the consumption of cutting fluid.However,long-term recycling of water-based cutting fluid could easily cause deterioration,and the breeding of bacteria could cause the cutting fluid to fail,increase manufacturing costs,and even endanger the health of workers.Traditional bactericides could improve the biological stability of cutting fluids,but they are toxic to the environment and do not conform to the development trend of low-carbon manufacturing.Low-carbon manufacturing is inevitable and the direction of sustainable manufacturing.The use of nanomaterials,transition metal complexes,and physical sterilization methods on the bacterial cell membrane and genetic material could effectively solve this problem.In this article,the mechanism of action of additives and microbial metabolites was first analyzed.Then,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were summarized.Further,the mechanism of nanomaterials disrupting cell membrane potential was discussed.The effects of lipophilicity and the atomic number of transition metal complexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were reviewed.In other words,the bactericidal performance,hazard,degradability,and economics of various sterilization methods were comprehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.
文摘Objective:To ascertain the potential antibacterial activity of honey against clinical isolates of Escherichia coli(E.coli),Pseudomonas aeruginosa(P.aeruginosa) and Salmonella enterica serovar Typhi(S.enterica serovar Typhi) by in vitro methods.Methods:The partial inhibitory concentration(PIC),minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) values of the autoclaved honey(extracted from Apis indica hive by indigenous method) were determined for S.enterica serovar Typhi(n=8:from blood cultute), E.coli(n=5:from urine culture) and P.aeruginosa(n=5:from pus culture) isolates by in vitro methods.Results:The PICs of the honey tested for the isolates ranged 0.50%-1.25%(v/v) for S. enterica serovar Typhi,0.75%-1.50%(v/v) for E.coli and 1.00%-1.25%(v/v) for P.aeruginosa, while the MICs ranged 1.75%-3.00%(v/v),3.00%-3.50%(v/v) and 3.50%(v/v),respectively.The P.aeruginosa and E.coli isolates had MBC value of 4.00%(v/v):the S.enterica serovar Typhi showed MBCs in between 3.00%and 3.50%(v/v).The bactericidal activity of honey was achieved at concentration 3.00%(v/v) for S.enterica serovar Typhi and E.coli,and at 3.50%(v/v) for P. aeruginosa.Conclusions:The excellent antibacterial activity of honey against clinical bacterial isolates indicates the usefulness of honey in clinical practice against bacterial infection.
基金Supported by National Natural Science Foundation Project of China,No.81072952
文摘AIM: To investigate the bactericidal effects of Chenopodium ambrosioides L.(CAL) against Helicobacter pylori(H.pylori) both in vitro and in vivo.METHODS: For in vitro experiments, the inhibitory activity of CAL was tested using an agar dilution method; H.pylori strain NCTC11637 was incubated on Columbia blood agar plates containing serial concentrations of CAL.The minimal inhibitory concentration(MIC) was determined by the absence of H.pylori colonies on the agar plate.Time-kill curves were used to evaluate bactericidal activity; the average number of colonies was calculated at 0, 2, 8 and 24 h after liquid incubation with concentrations of CAL at 0.5, 1, and 2 × MIC.For in vivo experiments, H.pylori-infected mice were randomly divided into CAL, triple therapy(lansoprazole, metronidazole, and clarithromycin), blank control, or H.pylori control groups.The eradication ratios were determined by positive findings from rapid urease tests(RUTs) and by histopathology.RESULTS: In vitro, the MIC of CAL against H.pylori was 16 mg/L.The time-kill curves showed a stable and persistent decreasing tendency with increasing CAL concentration, and the intensity of the bactericidal effect was proportional to dose; the 1 and 2 × MIC completely inhibited the growth of H.pylori at 24 h.In vivo, the eradication ratios in the CAL group were60%(6/10) by RUT and 50%(5/10) by histopathology.Ratios in the triple therapy group were both 70%(7/10), and there was no difference between the CAL and triple therapy groups.Histopathologic evaluation revealed massive bacterial colonization on the surface of gastric mucosa and slight infiltration of mononuclear cells after inoculation with H.pylori, but no obvious inflammation or other pathologic changes in gastric mucosa of mice from CAL and triple therapy groups.CONCLUSION: CAL demonstrates effective bactericidal activity against H.pylori both in vitro and in vivo.
基金financially supported by the National Natural Science Foundation of China(Nos.U2106226,U22A0183,52105297)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)+2 种基金the Science and Technology Development Project of Jilin Province(Nos.20210203022SF,20210508029RQ)the JLU Science and Technology Innovative Research Team(No.2020TD-03)the Project funded by China Postdoctoral Science Foundation(No.2022TQ0117).
文摘Superhydrophobic surfaces with water-repelling ability have important applications, such as self-cleaning, antibacterial and corrosion protection. However, the using of harmful fluorinated materials and its poor mechanochemical stability limit its practical application. Herein, a fluorine-free, robust and self-healing superhydrophobic surface is prepared through a two-step method of laser processing and spraying coating for anticorrosion and antibacterial applications. Laser processing is used to construct periodic micron-sized pillars for obtaining strong interface bonding between coating and substrate by mechanical interlocking effect, and as an ‘armor’, preventing the removal of the coating. The coating consists of epoxy resin (EP), hexadecyltrimethoxysilane (HDTMS) and γ-aminopropyltriethoxysilane treated Cu2O (KH550-Cu2O). The superhydrophobic surface can withstand various mechanical durability tests, such as multiple sandpaper abrasion and tape peeling cycles. It exhibits excellent corrosion inhibition efficiency (ηp > 99 %) on Mg alloy, Tinplate and Al alloy, which results from superhydrophobicity and organic coating. The superhydrophobicity endows surface with excellent antibacterial adhesion performance in a static liquid environment. The bactericidal activity of KH550-Cu2O can effectively inactivate the bacteria in contact with the surface and the free bacteria, providing excellent antibacterial ability in a dynamic liquid environment. It still exhibits good anticorrosion and antibacterial abilities after multiple mechanical abrasion cycles due to the outstanding mechanical durability. Moreover, it exhibits outstanding self-healing ability to plasma etching and oil contamination, self-cleaning ability under air and oil conditions, and chemical stability against acids and alkalis solution. All the above excellent performances promote its application in a wider range of fields.
基金financially supported by the National Natural Science Foundation of China(Nos.21774086 and 21935008)the Natural Science Foundation of Jiangsu Province(No.BK20180093)+1 种基金the Suzhou Municipal Science and Technology Foundation(No.SYS2018026)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Attachment of bacteria and subsequent formation of biofilms on material surfaces lead to serious consequences including infection,contamination and biofouling,posing a prominent threat to human health and causing problems in many industries.Therefore,it is highly desirable to endow the surfaces with antibacterial properties.Traditional antibacterial surfaces are designed via either bacteria-resisting strategy to prevent the initial adhesion of bacteria or bacteria-killing strategy to eradicate any bacteria that attach to the surface.However,these single-function surfaces have their inherent shortcomings and cannot realize long-term efficacy against bacteria.In recent years,various dual-function antibacterial surfaces with both bacteria-resisting and bacteria-killing properties together have been developed,showing better performance for combating surface-attached bacteria and preventing formation of biofilms.In this review,we summarize the recent development of these dual-function antibacterial surfaces.We focus on the design principles and fabrication strategies of such surfaces and highlight the representative examples,which are categorized specifically into two types according to the anti-adhesive and bactericidal properties are simultaneous or switchable.A brief perspective is finally presented on current challenges and future research directions.
文摘It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.
基金Supported by University of Condar(UOG/Budget/no.6215),Condar,Ethiopia
文摘Objective:To investigate the synergic antibacterial activity of garlic and tazma honey against standard and clinical pathogenic bacteria.Methods:Antimicrobial activity of tazma honey,garlic and mixture of them against pathogenic bacteria were determined.Chloramphenicol and water were used as positive and negative controls,respectively.Minimum inhibitory concentration(MIC)and minimum bactericidal concentration of antimicrobial samples were determined using standard methods.Results:Inhibition zone of mixture of garlic and tazma honey against all tested pathogens was significantly(P≤0.05)greater than garlic and tazma honey alone.The diameter zone of inhibition ranged from(18±1)to(35±1)mm for mixture of garlic and tazma honey,(12±1)to(20±1)nun for tazma honey and(14±1)to(22±1)mm for garlic as compared with(10±1)to(30±1)mm for chloramphenicol.The combination of garlic and tazma honey(30-35 mm)was more significantly(P≤0.05)effective against Salmonella(NCTC 8385),Staphylococcus aureus(ATCC 25923),Lyesria moncytogenes(ATCC 19116)and Streptococcus pneumonia(ATCC 63).Results also showed considerable antimicrobial activity of garlic and tazma honey.MIC of mixture of garlic and tazma honey at 6.25%against total test bacteria was 88.9%.MIC of mixture of garlic and tazma honey at6.25%against Gram positive and negative were 100%and 83.33%,respectively.The bactericidal activities of garlic,tazma honey,and mixture of garlic and tazma honey against all pathogenic bacteria at 6.25%concentration were 66.6%,55.6%and 55.6%,respectively.Conclusions:This finding strongly supports the claim of the local community to use the combination of tazma honey and garlic for the treatment of different pathogenic bacterial infections.Therefore,garlic in combination with tazma honey can serve as an alternative natural antimicrobial drug for the treatment of pathogenic bacterial infections.Further in vivo study is recommended to come up with a comprehensive conclusion.
文摘Objective:To evaluate antibacterial activity of hot and cold ethanol and methanol leaf extracts of Ricinus communis L(R.communis)against Staphylococcus aureus(S.aureus)(NCTC 6571)and Escherichia coli(E.coli)(ATCC 25922).Methods:Leaf powder of R.communis L.was extracted with hot(in Soxhlet)and cold ethanol and methanol,separately.The antibacterial activity of the extracts was determined by agar well diffusion and macro broth dilution methods.The extracts were also subjected to phytochemical analysis.Results:All the four test extracts showed inhibition on both S.aureus and E.coli.Hot and cold ethanol extracts revealed significantly(P<0.05)higher inhibition on S.aureus than methanol extracts,and the hot ethanol extract had the lowest minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)values(5 mg/mL and 10 mg/mL,respectively).E.coli was highly inhibited by hot extracts of both ethanol and methanol with the MIC and MBC of 40 mg/mL and 80 mg/mL,respectively.Phytochemical analysis revealed the presence of saponins,cardiac glycosides,tannins,flavonoids and terpenoids in all test extracts.Conclusions:This study demonstrates that the hot and cold methanol and ethanol extracts are potential sources for control of S.aureus and E.coli.Especially,the hot and cold extracts of ethanol are more inhibitive against 5.aureus even at lower concentration.Further study is needed to identify the specific bioactive compounds,their mode of action and their nontoxic nature in vivo condition.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51873212 and 51803212)the Youth Innovation Promotion Association of Chinese Academy Science(No.2017269)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019MEM008)Chinese Academy of Sciences-Wego Group Hightech Research&Development Program.
文摘Bacterial biofilm infections have been threatening the human’s life and health globally for a long time because they typically cause chronic and persistent infections.Traditional antibiotic therapies can hardly eradicate biofilms in many cases,as biofilms always form a robust fortress for pathogens inside,inhibiting the penetration of drugs.To address the issues,many novel drug carriers emerged as promising strategies for biofilm treatment.Among them,stimuli-responsive nanocarriers have attracted much attentions for their intriguing physicochemical properties,such as tunable size,shape and surface chemistry,especially smart drug release characteristic.Based on the microenvironmental difference between biofilm infection sites and normal tissue,many stimuli,such as bacterial products accumulating in biofilms(enzymes,glutathione,etc.),lower pH and higher H_(2)O_(2)levels,have been employed and proved in favor of“on-demand”drug release for biofilm elimination.Additionally,external stimuli including light,heat,microwave and magnetic fields are also able to control the drug releasing behavior artificially.In this review,we summarized recent advances in stimuli-responsive nanocarriers for combating biofilm infections,and mainly,focusing on the different stimuli that trigger the drug release.
基金supported by National Natural Science Foundation of China (Grant Nos. 51722705 and 51837008)
文摘In this paper,the influences of gas doping(O2,N2,Air)on the concentrations of reactive species and bactericidal effects induced by a He plasma jet are studied.Firstly,results show that gas doping causes an increase in voltage and a decrease in current compared with the pure He discharge under the same discharge power,which might be attributed to the different chemical characteristics of O2 and N2 and verified by the changes in the gaseous reactive species shown in the optical emission spectroscopy(OES)and Fourier transform infrared(FTIR)spectroscopy.Secondly,the concentrations of aqueous reactive oxygen species(ROS)and reactive nitrogen species(RNS)are tightly related to the addition of O2 and N2 into the working gas.The concentrations of aqueous NO-2 and NO-3 significantly increase while the concentrations of aqueous ROS decrease with the admixture of N2.The addition of O2 has little effect on the concentrations of NO-2 and NO-3 and pH values;however,the addition of O2 increases the concentration of O-2 and deceases the concentrations of H2O2 and OH.Finally,the results of bactericidal experiments demonstrate that the inactivation efficiency of the four types of plasma jets is He+O2>He+Air>He>He+N2,which is in accordance with the changing trend of the concentration of aqueous O.-2 Simultaneously to the better understanding of the formation and removal mechanisms of reactive species in the plasma–liquid interaction,these results also prove the effectiveness of regulating the concentrations of aqueous reactive species and the bacteria inactivation effects by gas doping.
文摘To investigate the scientific bases for t/te traditional use of Stachy-tarpheta angustifolia. Methods: In vitro antibacterial activity of the aqueous and ethanol extract of the plant was investigated using the agar cup plate diffusion method. Results: The ethanol extract of the plant showed antibacterial activity against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Slaphylococcus aureus (S. aureus) , Salmonella sp. , Pseudomonas aeruginosa and Neisseria gonor-r/iaeae, while the water extract was active against Escherichia coli, Streptococcus faecalis, Shigella dysenterme, Sta-phylococcus aureus and. Pseudomonas aeruginosa. The etlianol extract exhibited higher antibacterial activity than the water extract. The minimum inhibitory concentration (MIC) and minimum bactericidal, concentration (MBC} of the ethanol extract were 0. 65 mg/mt and 0. 85 mg/ml, respectively , against S. aureus. Treatment of the extract at higher temperature, 60℃ increased the sensitivity of the test organisms to the plant extract. Phytochemical analysis indicated t/tat the plant possesses tannins, saponins as well as phenols. Conclusion: A scientific basis exists that the plant possesses antibacterial activity and it could be a probable source of therapeutic agent.
基金financially supported by the National Natural Science Foundation of China(Nos.81803481,81830103 and 31900982)the Shenzhen Science and Technology Program(Nos.KQTD20190929173853397 and JCYJ20200109142401698)+1 种基金the Fundamental Research Funds for the Central Universities of China(Nos.20ykpy123 and 19ykpy142)the Institute of Bioengineering and Nanotechnology(Biomedical Research Council,Agency for Science,Technology and Research,Singapore)(Nos.SC 19/08-101002)。
文摘Bacterial infections associated with biomedical devices and implants have posed a great challenge to global healthcare systems.These infections are mainly caused by bacterial biofilm formed on the surface of biomaterials,protecting the encapsulated bacteria from conventional antibiotic treatment and attack of the immune system.As the bacterial biofilm is difficult to eradicate,bactericidal and antifouling coatings have emerged as promising strategies to prevent biofilm fo rmation and subsequent infections.Hydrogels with three-dimensional crosslinked hydrophilic networks,tunable mechanical property and large drugloading capacity are desirable coating materials,which can kill bacteria and/or prevent bacterial adhesion on the surface,inhibiting biofilm formation.Herein,we review recent developments of hydrogels as anti-infective coatings.Particularly,we highlight two chemical approaches(graft-from and graft-to),which have been used to immobilize hydrogels on surfaces,and present advances in the development of bactericidal(contact-killing and antimicrobial-releasing),antifouling(hydrophilic polymer network)and bifunctional hydrogel coatings with both bactericidal and antifouling activities.In addition,the challe nges of hydrogel coatings for clinical applications are discussed,and future research directions of anti-infective hydrogel coatings are proposed.
基金financially supported by the National Natural Science Foundation of China(No.22078077)the National Science Foundation of Guangdong Province(No.2021A1515010078)financial support of Taif University Researchers Supporting Project(No.TURSP-2020/14),Taif University,Taif,Saudi Arabia。
文摘Although many material designs or strategic methods have been proposed for treating oil spills and oily wastewater,the complex oily state,dealing with the harsh operating conditions of oil–water separation(such as the recovery of viscous spilled crude oil,bacteria-containing oily wastewater,and removal of spilled oil under fire),and the autorecycling of oil and absorption materials remain a great challenge.This work proposed an ingenious design strategy of“several birds with one stone”to prepare p H/thermoresponsive flame-retardant/photothermal bactericidal P-Fe_(3)O_(4)-polydopamine(PDA)@melamine–formaldehyde(MF)foams.This design makes the foams remarkably effective in the recovery of spilled viscous crude oil as well as in the separation of bacteria-containing oily emulsions,particularly for instant fire extinguishing by magnetically controlled oil absorption as well as for fire alarms.The photothermal effect and p H response induce a change in the surface wettability of the foams,facilitating excellent autoadsorption/desorption of the spilled oil.The photothermal bactericidal activity and fouling resistance of the foam are beneficial to the separation of bacteria-containing oily wastewater.Outstanding flame-retardant properties and maneuverable magnetic control enable the foam to rapidly recover the spilled oil in a large range of fires,extinguish fires instantly,and facilitate early fire warning.The proposed strategy is expected to inspire further research on treating oil spills under complex conditions.
