scholarly journals The Influence of Polysaccharides/TiO2 on the Model Membranes of Dipalmitoylphosphatidylglycerol and Bacterial Lipids

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 343
Author(s):  
Agata Ładniak ◽  
Małgorzata Jurak ◽  
Marta Palusińska-Szysz ◽  
Agnieszka Ewa Wiącek
Keyword(s):  
Surface Pressure ◽  
Antibacterial Properties ◽  
Biological Membranes ◽  
Hysteresis Loops ◽  
Compression Modulus ◽  
Bacterial Membranes ◽  
E Coli ◽  
Cosmetic Ingredients ◽  
Bactericidal Properties ◽  
And Staphylococcus Aureus

The aim of the study was to determine the bactericidal properties of popular medical, pharmaceutical, and cosmetic ingredients, namely chitosan (Ch), hyaluronic acid (HA), and titanium dioxide (TiO2). The characteristics presented in this paper are based on the Langmuir monolayer studies of the model biological membranes formed on subphases with these compounds or their mixtures. To prepare the Langmuir film, 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DPPG) phospholipid, which is the component of most bacterial membranes, as well as biological material-lipids isolated from bacteria Escherichia coli and Staphylococcus aureus were used. The analysis of the surface pressure-mean molecular area (π-A) isotherms, compression modulus as a function of surface pressure, CS−1 = f(π), relative surface pressure as a function of time, π/π0 = f(t), hysteresis loops, as well as structure visualized using a Brewster angle microscope (BAM) shows clearly that Ch, HA, and TiO2 have antibacterial properties. Ch and TiO2 mostly affect S. aureus monolayer structure during compression. They can enhance the permeability of biological membranes leading to the bacteria cell death. In turn, HA has a greater impact on the thickness of E. coli film.

Probing structure–activity relationships in bactericidal peptide βpep-25

2008 ◽  
Vol 414 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Ruud P. M. Dings ◽  
Judith R. Haseman ◽  
Kevin H. Mayo
Keyword(s):  
Amino Acid Residues ◽  
Neutralization Activity ◽  
Bacterial Membranes ◽  
E Coli ◽  
Structure Activity Relationships ◽  
Optimal Activity ◽  
Structure Activity ◽  
Cationic Residues ◽  
Β Sheet ◽  
And Staphylococcus Aureus

Cationic peptides, known to disrupt bacterial membranes, are being developed as promising agents for therapeutic intervention against infectious disease. In the present study, we investigate structure–activity relationships in the bacterial membrane disruptor βpep-25, a peptide 33-mer. For insight into which amino acid residues are functionally important, we synthesized alanine-scanning variants of βpep-25 and assessed their ability to kill bacteria (Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus) and to neutralize LPS (lipopolysaccharide). Activity profiles were found to vary with the bacterial strain examined. Specific cationic and smaller hydrophobic alkyl residues were crucial to optimal bactericidal activity against the Gram-negative bacteria, whereas larger hydrophobic and cationic residues mediated optimal activity against Gram-positive Staph. aureus. Lysine-substituted norleucine (n-butyl group) variants demonstrated that both charge and alkyl chain length mediate optimal activity. In terms of LPS neutralization, activity profiles were essentially the same against four species of LPS (E. coli 055 and 0111, Salmonella enterica serotype Typhimurium and Klebsiella pneumoniae), and different for two others (Ps. aeruginosa and Serratia marcescens), with specific hydrophobic, cationic and, surprisingly, anionic residues being functionally important. Furthermore, disulfide-bridged analogues demonstrated that an anti parallel β-sheet structure is the bioactive conformation of βpep-25 in terms of its bactericidal, but not LPS endotoxin neutralizing, activity. Moreover, βpep-25 variants, like the parent peptide, do not lyse eukaryotic cells. This research contributes to the development and design of novel antibiotics.

scholarly journals Ex vivo antibacterial properties of rufloxacin compared with those of norfloxacin in a study with healthy volunteers.

1996 ◽  
Vol 40 (1) ◽  
pp. 17-21 ◽  
Author(s):  
L Aguilar ◽  
I P Balcabao ◽  
P Salvá ◽  
M Martín ◽  
J Costa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Trial ◽  
Ex Vivo ◽  
Antibacterial Properties ◽  
Adult Males ◽  
E Coli ◽  
Crossover Phase ◽  
Uncomplicated Cystitis ◽  
And Staphylococcus Aureus ◽  
Early Sample

Twelve adult males participated in a randomized crossover phase I clinical trial comparing serum bactericidal titers (SBTs), urine bactericidal titers (UBTs), and urine killing rates (UKRs) against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213, after the administration of single 400-mg doses of rufloxacin and norfloxacin at different times up to 72 h postdose. SBTs were significantly higher (P < 0.05) against E. coli from 8 to 48 h and against S. aureus from 4 to 24 h with rufloxacin. UBTs for E. coli were higher (P < 0.05) for norfloxacin at early sample times (0 to 8 h) but higher for rufloxacin (P < 0.05) at sample times from 16 h on for both E. coli and S. aureus. Similar UKRs were obtained for both quinolones for 0 to 2 h and 8 to 12 h, but the UKR was maintained for 72 h with rufloxacin. The high and sustained mean levels of rufloxacin in urine (> 35 micrograms/ml), median UBTs (> 32 for E. coli and 16 for S. aureus) and UKRs for E. coli suggest prolonged urine antibacterial activity (for at least 72 h) and its use as a single 400-mg dose in the treatment of uncomplicated cystitis.

scholarly journals Co-Networks Poly(hydroxyalkanoates)-Terpenes to Enhance Antibacterial Properties

2020 ◽  
Vol 7 (1) ◽  
pp. 13 ◽  
Author(s):  
Tina Modjinou ◽  
Davy Louis Versace ◽  
Samir Abbad Andaloussi ◽  
Valérie Langlois ◽  
Estelle Renard
Keyword(s):  
Crosslinking Agent ◽  
Antibacterial Properties ◽  
Weight Ratio ◽  
Mechanical Resistance ◽  
Elongation At Break ◽  
Ene Reaction ◽  
E Coli ◽  
Mechanical Performances ◽  
Chemical Association ◽  
And Staphylococcus Aureus

Biocompatible and biodegradable bacterial polyesters, poly(hydroxyalkanoates) (PHAs), were combined with linalool, a well-known monoterpene, extracted from spice plants to design novel antibacterial materials. Their chemical association by a photo-induced thiol-ene reaction provided materials having both high mechanical resistance and flexibility. The influence of the nature of the crosslinking agent and the weight ratio of linalool on the thermo-mechanical performances were carefully evaluated. The elongation at break increases from 7% for the native PHA to 40% for PHA–linalool co-networks using a tetrafunctional cross-linking agent. The materials highlighted tremendous anti-adherence properties against Escherichia coli and Staphylococcus aureus by increasing linalool ratios. A significant decrease in antibacterial adhesion of 63% and 82% was observed for E. coli and S. aureus, respectively.

scholarly journals Comparative Study of Physicochemical and Antibacterial Properties of ZnO Nanoparticles Prepared by Laser Ablation of Zn Target in Water and Air

2018 ◽  
Author(s):  
Ekaterina A. Gavrilenko ◽  
Daria A. Goncharova ◽  
Ivan N. Lapin ◽  
Anna L. Nemoikina ◽  
Valery A. Svetlichnyi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Zno Nanoparticles ◽  
Biomedical Applications ◽  
Antibacterial Properties ◽  
Pulsed Laser ◽  
Wound Dressings ◽  
E Coli ◽  
Nanosecond Pulsed Laser ◽  
Bactericidal Properties ◽  
Biodegradable Poly

Here, we report on ZnO nanoparticles (NPs) generated by nanosecond pulsed laser (Nd:YAG, 1064 nm) through ablation of metallic Zn target in water and air and their comparative analysis as potential nanomaterials for biomedical applications. The prepared nanomaterials were carefully characterized in terms of their structure, composition, morphology and defects. It was found that in addition to the main wurtzite ZnO phase, which is conventionally prepared and reported by others, the sample laser-generated in air also contained some amount of monoclinic zinc hydroxynitrate. Both nanomaterials were then used to modify model wound dressings based on biodegradable poly-L-lactic acid. The as-prepared model dressings were tested as biomedical materials with bactericidal properties towards S. aureus and E. coli strains. The advantages of the NPs prepared in air over their counterparts generated in water found in this work are discussed.&nbsp; &nbsp;

scholarly journals Bioactivity and Antibacterial Behaviors of Nanostructured Lithium-Doped Hydroxyapatite for Bone Scaffold Application

2021 ◽  
Vol 22 (17) ◽  
pp. 9214 ◽  
Author(s):  
Pardis Keikhosravani ◽  
Hossein Maleki-Ghaleh ◽  
Amir Kahaie Khosrowshahi ◽  
Mahdi Bodaghi ◽  
Ziba Dargahi ◽  
...  
Keyword(s):  
Antibacterial Properties ◽  
Xrd Analysis ◽  
Bone Scaffold ◽  
Cell Analysis ◽  
Cellular Behavior ◽  
E Coli ◽  
Li Doping ◽  
Cold Pressed ◽  
And Staphylococcus Aureus ◽  
Li Content

The material for bone scaffold replacement should be biocompatible and antibacterial to prevent scaffold-associated infection. We biofunctionalized the hydroxyapatite (HA) properties by doping it with lithium (Li). The HA and 4 Li-doped HA (0.5, 1.0, 2.0, 4.0 wt.%) samples were investigated to find the most suitable Li content for both aspects. The synthesized nanoparticles, by the mechanical alloying method, were cold-pressed uniaxially and then sintered for 2 h at 1250 °C. Characterization using field-emission scanning electron microscopy (FE-SEM) revealed particle sizes in the range of 60 to 120 nm. The XRD analysis proved the formation of HA and Li-doped HA nanoparticles with crystal sizes ranging from 59 to 89 nm. The bioactivity of samples was investigated in simulated body fluid (SBF), and the growth of apatite formed on surfaces was evaluated using SEM and EDS. Cellular behavior was estimated by MG63 osteoblast-like cells. The results of apatite growth and cell analysis showed that 1.0 wt.% Li doping was optimal to maximize the bioactivity of HA. Antibacterial characteristics against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were performed by colony-forming unit (CFU) tests. The results showed that Li in the structure of HA increases its antibacterial properties. HA biofunctionalized by Li doping can be considered a suitable option for the fabrication of bone scaffolds due to its antibacterial and unique bioactivity properties.

scholarly journals Comparative Study of Physicochemical and Antibacterial Properties of ZnO Nanoparticles Prepared by Laser Ablation of Zn Target in Water and Air

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 186 ◽  
Author(s):  
Ekaterina A. Gavrilenko ◽  
Daria A. Goncharova ◽  
Ivan N. Lapin ◽  
Anna L. Nemoykina ◽  
Valery A. Svetlichnyi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Zno Nanoparticles ◽  
Biomedical Applications ◽  
Antibacterial Properties ◽  
Pulsed Laser ◽  
Wound Dressings ◽  
E Coli ◽  
Nanosecond Pulsed Laser ◽  
Bactericidal Properties ◽  
Biodegradable Poly

Here, we report on ZnO nanoparticles (NPs) generated by nanosecond pulsed laser (Nd:YAG, 1064 nm) through ablation of metallic Zn target in water and air and their comparative analysis as potential nanomaterials for biomedical applications. The prepared nanomaterials were carefully characterized in terms of their structure, composition, morphology and defects. It was found that in addition to the main wurtzite ZnO phase, which is conventionally prepared and reported by others, the sample laser generated in air also contained some amount of monoclinic zinc hydroxynitrate. Both nanomaterials were then used to modify model wound dressings based on biodegradable poly l-lactic acid. The as-prepared model dressings were tested as biomedical materials with bactericidal properties towards S. aureus and E. coli strains. The advantages of the NPs prepared in air over their counterparts generated in water found in this work are discussed.

Synthesis and photo-bactericidal properties of a cationic porphyrin grafted onto kraft pulp fibers

2019 ◽  
Vol 23 (04n05) ◽  
pp. 489-496 ◽  
Author(s):  
Zineb Khaldi ◽  
Jean K. Nzambe Takeki ◽  
Tan-Sothea Ouk ◽  
Romain Lucas ◽  
Rachida Zerrouki
Keyword(s):  
Kraft Pulp ◽  
Cycloaddition Reaction ◽  
Antibacterial Properties ◽  
Photodynamic Inactivation ◽  
Pulp Fibers ◽  
Cationic Porphyrin ◽  
Increased Risk ◽  
Bactericidal Properties ◽  
And Staphylococcus Aureus ◽  
Growth Of Bacteria

With the increased risk of infectious disease transmissions, photodynamic inactivation of some microorganisms for antimicrobial applications has been extensively studied in recent years. In this article, we describe the synthesis of novel photo-bactericidal materials by grafting propargylated 5,10,15,20-tetra(4-pyridyl)porphyrin on kraft pulp fibers. The grafting was carried out by a Huisgen’s 1,3-dipolar azide-alkyne cycloaddition reaction. This material has been investigated for its antibacterial properties against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. An interesting photo-bactericidal activity was shown: this material can be used to limit the growth of bacteria on surfaces and the formation of biofilms.

Photosensitive properties, synergistic antibacterial abilities of intelligent response-type self-assembled nanoparticle TiO2@V2O5

2020 ◽  
Vol 35 (6) ◽  
pp. 696-708
Author(s):  
Yanan Liu ◽  
Jiawei Liu ◽  
Xiaoping Guo ◽  
Ange Lin ◽  
Yayu Wen ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Pollution Control ◽  
Self Assembly ◽  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Response Type ◽  
E Coli ◽  
Antibacterial Materials ◽  
Related Cell ◽  
And Staphylococcus Aureus

Representative pathogenic bacteria such as Escherichia coli ( E. coli) and Staphylococcus aureus ( S. aureus) are widespread in nature and pose a threat to human health. To control the propagation of these pathogens from the source, the key is to design broad-spectrum antibacterial materials to reduce the serious damage of pathogenic bacteria. At present, more and more nanoparticles are widely researched and applied due to their multi-pathway antibacterial properties, such as regulating physiology, biochemistry and physical chemistry. In this work, we synthesized a uniformly dispersed and stable spherical nanoparticle (TiO2@V2O5) synthesized by self-assembly of tianium dioxide and vanadium pentoxide. Based on its excellent photosensitive properties, TiO2@V2O5 nanoparticles have showed excellent antibacterial properties under the light irradiation due to the production of hydroxyl radicals in antibacterial and mechanism tests. In addtion, related cell and plant experiments have showed that TiO2@V2O5 nanoparticles are excellent biocompatible materials, it could be widely used in environmental pollution control, limiting the serious damage caused by pathogens.

scholarly journals Composition and Antibacterial Effect of Mint Flavorings in Candies and Food Supplements

Planta Medica ◽  
2020 ◽  
Vol 86 (15) ◽  
pp. 1089-1096
Author(s):  
Karmen Kapp ◽  
Anne Orav ◽  
Mati Roasto ◽  
Ain Raal ◽  
Tõnu Püssa ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
Total Content ◽  
Food Supplements ◽  
Dilution Method ◽  
E Coli ◽  
First Time ◽  
And Staphylococcus Aureus ◽  
Broth Dilution

AbstractMint flavorings are widely used in confections, beverages, and dairy products. For the first time, mint flavoring composition of mint candies and food supplements (n = 45), originating from 16 countries, as well as their antibacterial properties, was analyzed. The flavorings were isolated by Marcussonʼs type micro-apparatus and analyzed by GC-MS. The total content of the mint flavoring hydrodistilled extracts was in the range of 0.01 – 0.9%. The most abundant compounds identified in the extracts were limonene, 1,8-cineole, menthone, menthofuran, isomenthone, menthol and its isomers, menthyl acetate. The antimicrobial activity of 13 reference substances and 10 selected mint flavoring hydrodistilled extracts was tested on Escherichia coli and Staphylococcus aureus by broth dilution method. Linalool acetate and (−)-carvone, as most active against both bacteria, had the lowest MIC90 values. (+)-Menthyl acetate, (−)-menthyl acetate, and limonene showed no antimicrobial activity. Three of the tested extracts had antimicrobial activity against E. coli and 8 extracts against S. aureus. Their summary antimicrobial activity was not always in concordance with the activities of respective reference substances.

Quaternary ammonium salt–modified polyacrylonitrile/polycaprolactone electrospun nanofibers with enhanced antibacterial properties

2021 ◽  
pp. 004051752199718
Author(s):  
Hongnan Zhang ◽  
Tingting Zhang ◽  
Qiaohua Qiu ◽  
Xiaohong Qin
Keyword(s):  
Antibacterial Properties ◽  
Electrospun Nanofibers ◽  
Tensile Tests ◽  
Nanofibrous Membrane ◽  
E Coli ◽  
Small Pore Size ◽  
Small Pore ◽  
Inhibition Zones ◽  
Nanofibrous Membranes ◽  
And Staphylococcus Aureus

In this experiment, octadecyltrimethylammonium chloride (STAC), a cationic antibacterial agent, was designed to modify hydrolyzed polyacrylonitrile (PAN) through tight electrostatic attraction. Then, the modified PAN was successfully electrospun with polycaprolactone (PCL) to obtain PCL/PAN-STAC nanofibrous membranes with enhanced mechanical properties. The modified PAN was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and elemental analysis. The morphological, mechanical and antibacterial properties of nanofibrous membranes were investigated. The blended nanofibrous membrane presented a uniform and stable structure with small pore size. Tensile tests indicated that the mechanical property of PCL/PAN-STAC nanofibrous membrane was obviously enhanced by blending. Disk diffusion tests showed that the inhibition zones of PCL/PAN-STAC against Escherichia coli and Staphylococcus aureus were 7.56 ± 0.05 mm and 15.37 ± 0.34 mm, respectively. Shaking method indicated that the antibacterial activity against E. coli was as high as 96.20 ± 0.89% when the use of PCL/PAN-STAC reached 9 mg. Therefore, this antibacterial nanofibrous membrane is very favorable for applications such as protective filtration masks and wound dressing.

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