scholarly journals Effect of Silver Nanoparticles on Blue Light Phototoxicity against Fusobacterium nucleatum

Biophysica ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 405-412
Author(s):  
Uziel Jeffet ◽  
Shiri Livne ◽  
Arkadi Rahmanov ◽  
Nir Sterer
Keyword(s):  
Silver Nanoparticles ◽  
Cell Membrane ◽  
Blue Light ◽  
Bacterial Cell ◽  
Light Exposure ◽  
Membrane Damage ◽  
Fusobacterium Nucleatum ◽  
Oxygen Species ◽  
Cell Membrane Damage ◽  
Bacterial Cell Membrane

A previous study showed that sub-lethal exposure of blue light caused cell membrane damage in Fusobacterium nucleatum (Fn). The aim of the present study was to test the combined effect of blue light and silver nanoparticles against Fn. Bacterial suspensions were exposed to blue light (400–500 nm) with or without silver nanoparticles (10 nm). Exposed and non-exposed samples were studied for malodor production (Odor judge scores), VSC levels (Halimeter), reactive oxygen species (ROS) production (fluorimeter), and bacterial cell membrane damage (fluorescence microscopy). The results showed that combining blue light exposure and silver nanoparticles significantly reduced malodor and VSC production by Fn concomitant with increased ROS levels and bacterial cell membrane damage. These results suggest that silver nanoparticles may increase blue light phototoxicity against Fn.

scholarly journals Correlative ex situ and Liquid-Cell TEM Observation of Bacterial Cell Membrane Damage Induced by Rough Surface Topology

2020 ◽  
Vol Volume 15 ◽  
pp. 1929-1938 ◽  
Author(s):  
David Banner ◽  
Emre Firlar ◽  
Justas Jakubonis ◽  
Yusuf Baggia ◽  
Jodi Finlay ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Rough Surface ◽  
Bacterial Cell ◽  
Membrane Damage ◽  
Surface Topology ◽  
Ex Situ ◽  
Cell Membrane Damage ◽  
Liquid Cell ◽  
Bacterial Cell Membrane

scholarly journals A Biosurfactant-Sophorolipid Acts in Synergy with Antibiotics to Enhance Their Efficiency

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kasturi Joshi-Navare ◽  
Asmita Prabhune
Keyword(s):  
Cell Membrane ◽  
Pore Formation ◽  
Membrane Damage ◽  
Antimicrobial Properties ◽  
Synergistic Action ◽  
Gram Negative Bacteria ◽  
Cell Membrane Damage ◽  
Drug Molecules ◽  
Total Inhibition ◽  
Bacterial Cell Membrane

Sophorolipids (SLs), biosurfactants with antimicrobial properties, have been tried to address the problem of antibiotic resistance. The synergistic action of SL and antibiotics was checked using standard microdilution and spread plate methods. WithStaphylococcus aureus, SL-tetracycline combination achieved total inhibition before 4 h of exposure while tetracycline alone couldnot achieve total inhibition till the end of 6 h. The inhibition caused by exposure of bacterium to SL-tetracycline mixture was~25% more as compared to SL alone. In spite of known robustness of gram-negative bacteria, SL-cefaclor mixture proved to be efficient againstEscherichia coliwhich showed~48% more inhibition within 2 h of exposure as compared to cefaclor alone. Scanning electron microscopy of the cells treated with mixture revealed bacterial cell membrane damage and pore formation. Moreover, SLs being a type of asymmetric bola, they are expected to form self-assemblies with unique functionality. This led to the speculation that SLs being amphiphilic in nature can span through the structurally alike cell membrane and facilitate the entry of drug molecules.

scholarly journals Antimicrobial activity and mode of action of 1,8-cineol against carbapenemase-producing Klebsiella pneumoniae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chew-Li Moo ◽  
Mohd Azuraidi Osman ◽  
Shun-Kai Yang ◽  
Wai-Sum Yap ◽  
Saila Ismail ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antimicrobial Activity ◽  
Cell Membrane ◽  
Klebsiella Pneumoniae ◽  
Ethidium Bromide ◽  
Bacterial Cell ◽  
Mode Of Action ◽  
Membrane Damage ◽  
Electron Microscopies ◽  
Bacterial Cell Membrane

AbstractAntimicrobial resistance remains one of the most challenging issues that threatens the health of people around the world. Plant-derived natural compounds have received considerable attention for their potential role to mitigate antibiotic resistance. This study was carried out to assess the antimicrobial activity and mode of action of a monoterpene, 1,8-cineol (CN) against carbapenemase-producing Klebsiella pneumoniae (KPC-KP). Results showed that resazurin microplate assay and time-kill analysis revealed bactericidal effects of CN at 28.83 mg/mL. Zeta potential showed that CN increased the surface charge of bacteria and an increase of outer membrane permeability was also detected. CN was able to cause leakage of proteins and nucleic acids in KPC-KP cells upon exposure to CN and ethidium bromide influx/efflux experiment showed the uptake of ethidium bromide into the cell; this was attributed to membrane damage. CN was also found to induce oxidative stress in CN-treated KPC-KP cells through generation of reactive oxygen species which initiated lipid peroxidation and thus damaging the bacterial cell membrane. Scanning and transmission electron microscopies further confirmed the disruption of bacterial cell membrane and loss of intracellular materials. In this study, we demonstrated that CN induced oxidative stress and membrane damage resulting in KPC-KP cell death.

Design of bio-molecular interfaces using liquid crystals demonstrating endotoxin interactions with bacterial cell wall components

RSC Advances ◽  
2015 ◽  
Vol 5 (81) ◽  
pp. 66476-66486 ◽  
Author(s):  
Dibyendu Das ◽  
Sumyra Sidiq ◽  
Santanu Kumar Pal
Keyword(s):  
Cell Wall ◽  
Liquid Crystals ◽  
Cell Membrane ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Cell Wall Components ◽  
Bacterial Cell Membrane ◽  
Membrane Components ◽  
Wall Components

Liquid crystals offer a promising approach to study and quantify the interactions between different bacterial cell membrane components with endotoxin at an aqueous interface.

Particle Size of Drug Nanocarriers Defines the Fate of Spinal Cord Injury’s Recovery

2021 ◽  
Author(s):  
Delaram Poormoghadam ◽  
Bita Rasoulian Shiadeh ◽  
Fereshte Azedi ◽  
Hani Tavakol ◽  
Seyed Mahdi Rezayat ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Cell Membrane ◽  
Muscular Atrophy ◽  
Muscle Tone ◽  
Membrane Damage ◽  
Definitive Treatment ◽  
Detrusor Muscle ◽  
Cell Membrane Damage ◽  
Fty 720 ◽  
Cord Injury

Abstract Spinal cord injury (SCI) is a debilitating condition for which no definitive treatment has yet been identified. Noteworthy, it influences other tissues through inflammatory reactions and metabolic disturbance. Therefore, fingolimod (FTY-720) as an FDA-approved inflammatory modulator would be promising. In the present study, nanocarriers at two distinct monodisperse particle sizes of 60 (nF60) and 190 (nF190) nm were prepared.The neural stem cell (NSC) viability and LDH release were studied in the face of the nanocarriers and free FTY-720. Results indicated that nanocarriers and free FTY-720 enhanced NSC viability than the control group.However, nF190 significantly induced less cell membrane damage than nF60. Nanocarriers and free FTY-720 enhanced motor neuron recovery in SCI rats, while body weight and return to bladder reflux by nF190 was significantly higher than nF60 groups. Return to bladder reflux might be due to the role of FTY-720 in regulation of detrusor muscle tone and preservation of the integrity of vessels by acting on endothelial cells. Moreover,nF190 gained higher soleus muscle weight than the free drugs;probably decreasing pro-inflammatory cytokines in soleus diminish muscular atrophy in SCI rats.To sum thing up, larger nanacarrirs with less cell membrane damage seems to be more efficient than smaller ones to manage SCI.

Surface chemistry modification of silica nanoparticles alters the activation of monocytes

2021 ◽  
Author(s):  
Romina Mitarotonda ◽  
Martín Saraceno ◽  
Marcos Todone ◽  
Exequiel Giorgi ◽  
Emilio L Malchiodi ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Immune System ◽  
Cell Membrane ◽  
Cell Activation ◽  
Membrane Damage ◽  
Living Cells ◽  
Cell Membrane Damage ◽  
Study Materials ◽  
Therapeutic Molecules ◽  
Pro Inflammatory Cytokines

Aim: Nanoparticles (NPs) interaction with immune system is a growing topic of study. Materials & methods: Bare and amine grafted silica NPs effects on monocytes/macrophages cells were analyzed by flow cytometry, MTT test and LIVE/DEAD® viability/cytotoxicity assay. Results: Bare silica NPs inhibited proliferation and induced monocyte/macrophages activation (increasing CD40/CD80 expression besides pro-inflammatory cytokines and nitrite secretion). Furthermore, silica NPs increased cell membrane damage and reduced the number of living cells. In contrast, amine grafted silica NPs did not alter these parameters. Conclusion: Cell activation properties of bare silica NPs could be hindered after grafting with amine moieties. This strategy is useful to tune the immune system stimulation by NPs or to design NPs suitable to transport therapeutic molecules.

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