A Synergistic Antimicrobial Mechanism of GO: Why Oxidative Stress Can Inactivate E. coli

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050054 ◽  
Author(s):  
Xin Li ◽  
Haoqi Zhao ◽  
Shidong Wang ◽  
Weiwu Zou ◽  
Peiyan Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antibacterial Activity ◽  
Mammalian Cells ◽  
Water Solubility ◽  
Direct Interaction ◽  
Medical Application ◽  
Future Application ◽  
Sem Images ◽  
E Coli ◽  
Low Cytotoxicity

Graphene oxide (GO), a 2D nanomaterial, is a promising material for medical application, thanks to its water solubility, antibacterial activity and relatively low cytotoxicity. However, many factors, such as lateral dimension, purity and surface chemistry, may influence its antibacterial activity, its exact mechanism is still unknown. In this work, E. coli was used as model bacterium to determine the antibacterial activity of well-dispersed GO which was obtained by a modified Hummer method and dialyzed to remove the salts and acid used in the oxidation process. After co-culture with GO for 2[Formula: see text]h, up to 90% E. coli cells were inactivated when GO concentration at 8[Formula: see text][Formula: see text]g/mL. The direct interaction was not detected in FE-SEM images and the results of [Formula: see text] potential showed that the interaction between GO and E. coli are repulsive[Formula: see text] Our results showed that GO can produce ROS and inactivate SOD and CAT enzymes in low concentration after co-cultured with E. coli which explained the antibacterial activity of GO in aqueous solution. Meanwhile, GO, with high purity, showed low cytotoxicity towards mammalian cells and did not cause any observable hemoglobin after co-cultured with blood cells. The data presented here prove that GO is effectively inhibit E. coli through inactivating SOD, CAT enzymes and the oxidative stress produced by ROS. Furthermore, the good biocompatibility promised its future application.

scholarly journals Microemulsions as Nanoreactors for Preparation of Nanoparticles with Antibacterial Activity

2012 ◽  
Vol 25 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Sakhawat Hossain ◽  
Ummul K Fatema ◽  
Md Yousuf A Mollah ◽  
M Muhibur Rahman ◽  
Md Abu Bin Hasan susan
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Copper Chloride ◽  
Sodium Dodecyl ◽  
Antibiotic Sensitivity ◽  
Chemical Society ◽  
Molar Ratio ◽  
Electron Microscopic ◽  
Sem Images ◽  
E Coli

Nanoparticles of silver and copper have been synthesized by reduction of aqueous silver  nitrate and copper chloride solutions with sodium borohydride in anionic water-in-oil  (w/o) microemulsions, sodium dodecyl sulphate (SDS)/1-pentanol/cyclohexane/water.  Scanning electron microscopic (SEM) images, energy dispersive spectra (EDX) and UVspectra  have been used to characterize the resultant nanoparticles. The average size of the  nanoparticles has been found to be influenced by the water to surfactant molar ratio (Wo)  in the microemulsions. Smaller particles are obtained at low Wo, while higher Wo yields  larger particles. The antibiotic sensitivity of silver and copper nanoparticles against  Escherichia coli (E. coli) was tested by zone inhibition method using nanoparticles in  ethanol suspension. Both silver and copper nanoparticles showed the potential for use as  antibacterial agents against E. coli with sensitivity as good as conventional antibiotics.  Silver nanoparticles show higher antibacterial activity against E. coli, compared to copper nanoparticles. As the amount of the nanoparticles in the suspension decreases, antibacterial activity decreases; however the concentration dependence on antibacterial  activity has been less pronounced. DOI: http://dx.doi.org/10.3329/jbcs.v25i1.11777 Journal of Bangladesh Chemical Society, Vol. 25(1), 71-79, 2012

scholarly journals Ggrafted antimicrobial cotton fabrics with N-halamine groups via atom transfer radical polymerization

2021 ◽  
Author(s):  
Panpan Peng ◽  
Ziwen Zhang ◽  
Jianjun Yang ◽  
Mingyuan Wu ◽  
Qingyun Wu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Thermal Property ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Antibacterial Properties ◽  
Cotton Fabrics ◽  
Future Application ◽  
Atom Transfer ◽  
E Coli

Abstract An N-halamine precursor 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl methacrylate (SCMHBMA) was synthesized and grafted on cotton fabrics via atom transfer radical polymerization for antibacterial function after chlorination. The preparation and chlorinated cotton fabrics (Cotton-g-PSMA-Cl) were characterized with FTIR, XPS, SEM, and TGA. The properties of prepared Cotton-g-PSMA-Cl, including thermal property, antibacterial efficiency, durability, and stability, were systematically evaluated. The results showed that these chlorinated Cotton-g-PSMA-Cl fabrics possessed excellent antibacterial activity against E. coli. and S. aureus. After 10 washing cycles and 60 days of routine storage, active chlorine concentrations (Cl+%) were reduced only 22% and 18%, respectively, and the reduced Cl+% effectively reverted by simple rechlorination. This new N-halamine antibacterial cotton composite with superior antibacterial properties exhibited potential for future application in the long-term antibacterial field.

scholarly journals Development and Characterization of Polyphenon 60 and Caffeine Microemulsion for Enhanced Antibacterial Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Sonal Gupta ◽  
Rakhi Bansal ◽  
Javed Ali ◽  
Reema Gabrani ◽  
Shweta Dang
Keyword(s):  
Antibacterial Activity ◽  
Mammalian Cells ◽  
Average Particle Size ◽  
Natural Compounds ◽  
Average Particle ◽  
Tem Analysis ◽  
E Coli ◽  
Vero Cell Line ◽  
Effective Delivery ◽  
The Individual

Green tea catechins and caffeine have exhibited antibacterial activity; however, their use is limited by lack of stability and effective delivery systems. Polyphenon 60 (P60) and caffeine were encapsulated in a single microemulsion (ME) formulation with an objective to lower the minimum inhibitory concentrations (MICs) of the individual agents against selected pathogens (S. epidermidisandE. coli). Combination of two natural compounds would advocate two different mechanisms on the bacterial growth thereby providing for better antibacterial activity. Thermodynamically stable ME was developed and characterized with an average particle size of 17.58 nm, further confirmed by TEM analysis. Antibacterial studies included chequerboard microdilution assay to determine the MIC and fractional inhibitory concentration (FIC) of both the natural compounds individually and in combination. MIC and FIC results indicated that the combination of the above two natural compounds was proficient in lowering the MICs of individual agents. Results of DPPH assay indicated that ME system preserved the long term antioxidative potential of P60 and caffeine. The cytotoxicity of the optimized formulation on Vero cell line by MTT assay was found to be nontoxic to mammalian cells.

scholarly journals Value of monitoring Nrf2 activity for the detection of chemical and oxidative stress

2015 ◽  
Vol 43 (4) ◽  
pp. 657-662 ◽  
Author(s):  
Fiona E. Mutter ◽  
B. Kevin Park ◽  
Ian M. Copple
Keyword(s):  
Oxidative Stress ◽  
Mammalian Cells ◽  
Direct Interaction ◽  
Experimental Models ◽  
Related Factor ◽  
Nrf2 Pathway ◽  
Oxidative Stresses ◽  
Therapeutic Drugs ◽  
Numerous Cell ◽  
And Oxidative Stress

Beyond specific limits of exposure, chemical entities can provoke deleterious effects in mammalian cells via direct interaction with critical macromolecules or by stimulating the accumulation of reactive oxygen species (ROS). In particular, these chemical and oxidative stresses can underpin adverse reactions to therapeutic drugs, which pose an unnecessary burden in the clinic and pharmaceutical industry. Novel pre-clinical testing strategies are required to identify, at an earlier stage in the development pathway, chemicals and drugs that are likely to provoke toxicity in humans. Mammalian cells can adapt to chemical and oxidative stress via the action of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), which up-regulates the expression of numerous cell defence genes and has been shown to protect against a variety of chemical toxicities. Here, we provide a brief overview of the Nrf2 pathway and summarize novel experimental models that can be used to monitor changes in Nrf2 pathway activity and thus understand the functional consequences of such perturbations in the context of chemical and drug toxicity. We also provide an outlook on the potential value of monitoring Nrf2 activity for improving the pre-clinical identification of chemicals and drugs with toxic liability in humans.

scholarly journals DNA Microarray Analysis of the Expression Profile of Escherichia coli in Response to Treatment with 4,5-Dihydroxy-2-Cyclopenten-1-One

2002 ◽  
Vol 184 (23) ◽  
pp. 6725-6729 ◽  
Author(s):  
Sangita Phadtare ◽  
Ikunoshin Kato ◽  
Masayori Inouye
Keyword(s):  
Oxidative Stress ◽  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Microarray Analysis ◽  
Dna Microarray ◽  
Cell Metabolism ◽  
Response To Treatment ◽  
E Coli ◽  
Number Of Genes ◽  
Genes Encoding

ABSTRACT We carried out DNA microarray-based global transcript profiling of Escherichia coli in response to 4,5-dihydroxy-2-cyclopenten-1-one to explore the manifestation of its antibacterial activity. We show that it has widespread effects in E. coli affecting genes encoding proteins involved in cell metabolism and membrane synthesis and functions. Genes belonging to the regulon involved in synthesis of Cys are upregulated. In addition, rpoS and RpoS-regulated genes responding to various stresses and a number of genes responding to oxidative stress are upregulated.

scholarly journals NonToxic Silver/Poly-1-Vinyl-1,2,4-Triazole Nanocomposite Materials with Antibacterial Activity

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1477 ◽  
Author(s):  
Irina A. Shurygina ◽  
Galina F. Prozorova ◽  
Irina S. Trukhan ◽  
Svetlana A. Korzhova ◽  
Tatiana V. Fadeeva ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Mammalian Cells ◽  
Antimicrobial Properties ◽  
Fibroblast Cell ◽  
Nanocomposite Materials ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Fibroblast Cell Culture

Novel silver/poly-1-vinyl-1,2,4-triazole nanocomposite materials—possessing antimicrobial activity against Gram-positive and Gram-negative bacteria—have been synthesized and characterized in the solid state and aqueous solution by complex of modern physical-chemical and biologic methods. TEM-monitoring has revealed the main stages of microbial cell (E. coli) destruction by novel nanocomposite. The concept of direct polarized destruction of microbes by nanosilver proposed by the authors allows the relationship between physicochemical and antimicrobial properties of novel nanocomposites. At the same time, it was shown that the nanocomposite was nontoxic to the fibroblast cell culture. Thus, the synthesized nanocomposite combining antibacterial activity against Gram-positive and Gram-negative bacteria as well as the absence of toxic effects on mammalian cells is a promising material for the development of catheters, coatings for medical devices.

scholarly journals Cationic Anthraquinone Analogs as Selective Antimicrobials

2019 ◽  
Vol 12 ◽  
pp. 117863611984780
Author(s):  
Yagya Prasad Subedi ◽  
Cheng-Wei Tom Chang
Keyword(s):  
Staphylococcus Aureus ◽  
Broad Spectrum ◽  
Mammalian Cells ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
E Coli ◽  
Broad Spectrum Antibiotics ◽  
Drug Resistant Bacteria ◽  
New Antibiotics ◽  
Low Cytotoxicity

Development of new antibiotics is always needed in the fight against growing threat from multiple drug–resistant bacteria, such as resistant Gram-negative (G−) Escherichia coli and Klebsiella pneumoniae. While the development of broad-spectrum antibiotics has attracted great attention, careful administration of these antibiotics is important to avoid adverse effects, like Clostridium difficile infection (CDI). The use of broad-spectrum antibiotics, for example, quinolones, can increase the risk of CDI by eradicating the protective bacteria in intestine and encouraging C difficile spore germination. Many common intestine bacteria are G− or anaerobic, including Enterococcus faecalis, Bacteroides fragilis, and E coli. Hence, it may be advantageous in certain therapeutic practices to employ selective antimicrobials. For instance, Gram-positive (G+) methicillin-resistant Staphylococcus aureus (MRSA) that can cause life-threatening sepsis can be controlled with the use of selective antibiotic, vancomycin. Nevertheless, its effectiveness has been limited with the emerging of vancomycin-resistant Staphylococcus aureus (VRSA). A recent report on antimicrobial cationic anthraquinone analogs (CAAs) that show tunable activity and selectivity may provide new hope in the search for selective antimicrobials. In particular, the lead CAA displays prominent activity against MRSA while manifesting low activity against E coli and low cytotoxicity toward normal mammalian cells.

The Influence of Silver Nanoparticle Sizes on Antibacterial Activity, Cytotoxicity and Genotoxicity of Alginate Hydrogel Beads Containing Silver Nanoparticles

2019 ◽  
Vol 886 ◽  
pp. 70-77
Author(s):  
Pawika Mahasawat ◽  
Soraya Mudtaleb ◽  
Pratumporn Eaidprap
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Biomedical Applications ◽  
Hacat Cells ◽  
Alginate Hydrogel ◽  
Hydrogel Beads ◽  
E Coli ◽  
Low Cytotoxicity ◽  
Nanoparticle Sizes

Sizes of silver nanoparticles (AgNPs) have been shown to affect the biological activity of AgNPs. Hydrogel beads loaded with AgNPs have been extensively employed for biomedical applications. However, the influence of AgNPs sizes on biological activity of AgNP-loaded hydrogel beads has not much studied. Our objectives were to investigate the effect of AgNP sizes on the antibacterial activity, the cyto- and genotoxicity of AgNPs/alginate hydrogel beads. AgNPs of different sizes (⁓10 nm for S-AgNPs, and ⁓50 nm for L-AgNPs) were incorporated into alginate hydrogel beads during the preparation. The results showed that, S-AgNPs/alginate hydrogel beads (⁓89% inhibition) at AgNP concentration of 10 µg/ml tended to inhibit the growth of E. coli greater than L-AgNPs/alginate hydrogel beads (⁓49% inhibition) at the same dose. Moreover, at this effective antibacterial concentration (10 µg/ml), S-AgNPs/alginate hydrogel beads exhibited weak cytotoxic effect to HaCaT cells whereas L-AgNPs/alginate hydrogel beads showed non-cytotoxicity to this cell line. Furthermore, treatment of HaCaT cells with 10 µg/ml of S-AgNPs/ or L-AgNPs/alginate hydrogel beads did not result in a significant change in %DNA in tail when compared to untreated cells. Therefore, these AgNPs/alginate hydrogel beads, especially with smaller sized AgNPs, can be used as an antibacterial biomaterial with low cytotoxicity and genotoxicity to human cells.

C-Terminal Modifications Broaden Activity of the Proline-Rich Antimicrobial Peptide, Chex1-Arg20

2015 ◽  
Vol 68 (9) ◽  
pp. 1373 ◽  
Author(s):  
Wenyi Li ◽  
Julien Tailhades ◽  
M. Akhter Hossain ◽  
Neil M. O'Brien-Simpson ◽  
Eric C. Reynolds ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Peptide ◽  
Peptide Synthesis ◽  
Mammalian Cells ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Chemical Strategies

A series of N- and C-terminal modifications of the monomeric proline-rich antimicrobial peptide, Chex1-Arg20, was obtained via different chemical strategies using Fmoc/tBu solid-phase peptide synthesis in order to study their effects on a panel of Gram-negative bacteria. In particular, C-terminal modifications with hydrazide or alcohol functions extended their antibacterial activity from E. coli and K. pneumoniae to other Gram-negative species, A. baumannii and P. aeruginosa. Furthermore, these analogues did not show cytotoxicity towards mammalian cells. Hence, such modifications may aid in the development of more potent proline-rich antimicrobial peptides with a greater spectrum of activity against Gram-negative bacteria than the parent peptide.

scholarly journals Antibacterial Activity of Biodegradable Plastic from Chromolaena odorata (Pokok Kapal Terbang) Leaves

2021 ◽  
Vol 2071 (1) ◽  
pp. 012010
Author(s):  
C W S R Mohamad ◽  
E M Cheng ◽  
N A Abu Talib
Keyword(s):  
Antibacterial Activity ◽  
Medical Application ◽  
Sem Analysis ◽  
Chromolaena Odorata ◽  
Good Characteristic ◽  
Blend Films ◽  
E Coli ◽  
Antimicrobial Film ◽  
New Material ◽  
Broth Dilution

Abstract The aim of this research project was to develop antimicrobial films from blends of C. odorata and PVA and test the films for microbial activity using broth dilution methods for Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. The result shows that CO/PVA80 successfully inhibit the growth of target bacteria. In antibacterial activity analysis, CO/PVA80 showed 50% higher compare with pure PVA film, PVA100. Other than that, the high percentage of PVA in the blend films, the greater the thickness, Tensile Strength (TS) and Young’s Modulus (YM), while the Elongation Break (EB) of the prepared films decreased. The 0.5 mm CO/PVA80 film shows a good result in mechanical properties which is TS 6.55 MPa, YM 182 MPa and EB is 7.47%. A CO/PVA80 were show a smooth texture, lacked of macropore and good characteristic with a SEM analysis. These results suggest that CO/PVA80 films have good compatibility to form an antimicrobial film as a new material for medical application especially for wound healing.

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