scholarly journals Exploring electroactive microenvironments in polymer-based nanocomposites to sensitize bacterial cells to low-dose embedded silver nanoparticles

2021 ◽  
Author(s):  
Joana Moreira ◽  
Margarida M. Fernandes ◽  
Estela O. Carvalho ◽  
Ana Nicolau ◽  
Vesna Lazic ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Low Dose ◽  
Bacterial Cells

scholarly journals Effects of Baseplates of Orthodontic Appliances with in situ generated Silver Nanoparticles on Cariogenic Bacteria: A Randomized, Doubleblind Cross-over Clinical Trial

2015 ◽  
Vol 16 (4) ◽  
pp. 291-298 ◽  
Author(s):  
Roghayeh Ghorbanzadeh ◽  
Babak Pourakbari
Keyword(s):  
Clinical Trial ◽  
Silver Nanoparticles ◽  
Biofilm Formation ◽  
Orthodontic Appliances ◽  
Bacterial Cells ◽  
Streptococcus Sobrinus ◽  
Double Blind ◽  
Biofilm Inhibition ◽  
Cariogenic Bacteria

ABSTRACT Aim Polymethyl-methacrylate (PMMA) is commonly used primarily for baseplates of orthodontic appliances (BOA). The activities of cariogenic bacteria in biofilm on these surfaces may contribute to dental caries, gingival inflammation and periodontal disease. The PMMA incorporated with nanoparticles of silver (NanoAg-I-PMMA) and NanoAg in situ in PMMA (NanoAg-IS-PMMA) have been shown to control the growth of cariogenic bacteria, but clinical trial of anti-cariogenic application of these novel materials in orthodontics has not been evaluated. The main aim of the study is to compare the clinical effectiveness of using NanoAg-IS-PMMA and NanoAg-I-PMMA for construction of new BOA in inhibiting the planktonic growth and biofilm formation of the cariogenic bacteria. Materials and methods Twenty four patients with a median age of 12.6 years (7-15) harboring Streptococcus mutans, Streptococcus sobrinus and Lactobacillus acidophilus as well as Lactobacillus casei participated in the randomized, doubleblind, cross-over study. The experimental BOA, NanoAg-ISBOA and NanoAg-I-BOA, contained 0.5% w/w NanoAg while the control BOA was standard PMMA. Antibacterial effect of NanoAg-IS-BOA and NanoAg-I-BOA was assessed against test cariogenic bacteria by planktonic and biofilm bacterial cells growth inhibition. Results The average levels of test cariogenic bacteria in saliva decreased about 2 to 70 fold (30.9-98.4%) compared to baseline depending on the microorganism type and test BOA. Biofilm inhibition analysis demonstrated that NanoAg-I-BOA and NanoAg-IS-BOA inhibited the biofilm of all test bacteria by 20.1 to 79.9% compared to BOA. NanoAg-IS-BOA had a strong anti-biofilm effect against S. mutans, S. sobrinus and L. casei. However, NanoAg-I-BOA showed only slight antibiofilm effects on test bacteria. Most notably, at all period of the clinical trial, NanoAg-IS-BOA showed a higher antibacterial activity than NanoAg-I-BOA. Conclusion Based on the novel data that presented here, the NanoAg-IS-BOA had strong antimicrobial activity in the planktonic phase and subsequent biofilm formation of the cariogenic bacteria. Clinical significance Wearing of NanoAg-IS-BOA has the potential to minimize dental plaque formation and caries during orthodontic treatment. How to cite this article Ghorbanzadeh R, Pourakbari B, Bahador A. Effects of Baseplates of Orthodontic Appliances with in situ generated Silver Nanoparticles on Cariogenic Bacteria: A Randomized, Double-blind Cross-over Clinical Trial. J Contemp Dent Pract 2015;16(4):291-298.

scholarly journals Titanium Dioxide Nanoparticles Elicit Lower Direct Inhibitory Effect on Human Gut Microbiota Than Silver Nanoparticles

2019 ◽  
Vol 172 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Richard T Agans ◽  
Alex Gordon ◽  
Saber Hussain ◽  
Oleg Paliy
Keyword(s):  
Silver Nanoparticles ◽  
Titanium Dioxide ◽  
Gut Microbiota ◽  
Titanium Dioxide Nanoparticles ◽  
Close Association ◽  
Community Diversity ◽  
Bacterial Cells ◽  
Human Gut ◽  
Human Gut Microbiota

Abstract Due to continued technological development, people increasingly come in contact with engineered nanomaterials (ENMs) that are now used in foods and many industrial applications. Many ENMs have historically been shown to possess antimicrobial properties, which has sparked concern for how dietary nanomaterials impact gastrointestinal health via microbial dysbiosis. We employed an in vitro Human Gut Simulator system to examine interactions of dietary nano titanium dioxide (TiO2) with human gut microbiota. Electron microscopy indicated a close association of TiO2 particles with bacterial cells. Addition of TiO2 to microbial communities led to a modest reduction in community density but had no impact on community diversity and evenness. In contrast, administration of known antimicrobial silver nanoparticles (NPs) in a control experiment resulted in a drastic reduction of population density. In both cases, communities recovered once the addition of nanomaterials was ceased. Constrained ordination analysis of community profiles revealed that simulated colonic region was the primary determinant of microbiota composition. Accordingly, predicted community functional capacity and measured production of short-chain fatty acids were not changed significantly upon microbiota exposure to TiO2. We conclude that tested TiO2 NPs have limited direct effect on human gut microbiota.

scholarly journals Surface-Enhanced Raman Scattering of Bacteria in Microwells Constructed from Silver Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mustafa Çulha ◽  
M. Müge Yazıcı ◽  
Mehmet Kahraman ◽  
Fikrettin Şahin ◽  
Sesin Kocagöz
Keyword(s):  
Silver Nanoparticles ◽  
Raman Scattering ◽  
Surface Enhanced Raman Scattering ◽  
Growth Media ◽  
Bacterial Cells ◽  
Convective Assembly ◽  
Assembly Method ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Whole bacterial cell characterization is critically important for fast bacterial identification. Surface-enhanced Raman scattering (SERS) is proven to be powerful technique to serve such a goal. In this study, the characterization of whole bacterial cells in the microwells constructed from colloidal silver nanoparticles (AgNPs) with “convective-assembly” method is reported. The proper size of the microwells for the model bacteria,Escherichia coliandStaphylococcus cohnii, is determined to be 1.2 μm from their electron microscopy images. A minimum dilution factor of 20 is necessary for the bacterial samples collected from growth media to diminish the bacterial aggregation to place the bacterial cells into the microwells. The constructed microwell structures are tested for their bacterial SERS performance and compared to the SERS spectra obtained from the samples prepared with a simple mixing of bacteria and AgNPs for the same bacteria. The results indicate that microwell structures not only improve the spectral quality but also increase the reproducibility of the SERS spectra.

scholarly journals Blood Biochemical and Hematological Study after Subacute Intravenous Injection of Gold and Silver Nanoparticles and Coadministered Gold and Silver Nanoparticles of Similar Sizes

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ji Hyun Lee ◽  
Mary Gulumian ◽  
Elaine M. Faustman ◽  
Tomomi Workman ◽  
KiSoo Jeon ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Low Dose ◽  
Systemic Toxicity ◽  
Blood Biochemistry ◽  
Control Group ◽  
High Dose ◽  
Sprague Dawley ◽  
Gold And Silver Nanoparticles ◽  
Blood Biochemical ◽  
Active Partial Thromboplastin Time

Background. To investigate the effect of subacute intravenous administration AgNP (silver nanoparticles, 10 nm) and AuNP (gold nanoparticles, 12.8 nm) and AgNP/AuNP mixture to blood biochemistry, hematology, and platelet coagulation, subacute toxicity study was conducted. Methods. AuNP and AgNP in which their size distribution was not statistically different, mixed or separate, were injected into the caudal vein of male Sprague-Dawley rats for 4 weeks. The rats were allowed to recover for a further 4 weeks in order to examine systemic toxicity expressed in the blood biochemistry and hematology. The dose groups (5 males per group for the administration and 3 males for the recovery) consisted of 7 divisions, i.e., control, AgNP (with a low dose of 10 μg/kg/day and a high dose of 100 μg/kg/day), AuNP (with a low dose of 10 μg/kg/day and a high dose of 100 μg/kg/day), and mixed AgNP/AuNP (with a low dose of 10/10 μg/kg/day and a high dose of 100/100 μg/kg/day). Results. There were no significant dose-related changes in the hematology and blood biochemical values for the rats. Coagulation time in terms of the active partial thromboplastin time (APTT) and prothrombin time (PT) did not show any significant changes, when compared to the control group. Conclusion. The subacute injection of AuNP and AgNP or their mixture did not induce any noticeable systemic toxicity.

Influence of a low dose of silver nanoparticles on cerebral myelin and behavior of adult rats

Toxicology ◽  
2016 ◽  
Vol 363-364 ◽  
pp. 29-36 ◽  
Author(s):  
Beata Dąbrowska-Bouta ◽  
Mateusz Zięba ◽  
Jolanta Orzelska-Górka ◽  
Joanna Skalska ◽  
Grzegorz Sulkowski ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Low Dose ◽  
Adult Rats ◽  
And Behavior

Antimicrobial Effects of Silver Nanoparticles against Bacterial Cells Adhered to Stainless Steel Surfaces

2012 ◽  
Vol 75 (4) ◽  
pp. 701-705 ◽  
Author(s):  
EMILIANE A. ARAÚJO ◽  
NÉLIO J. ANDRADE ◽  
LUIS HENRIQUE M. da SILVA ◽  
PATRÍCIA C. BERNARDES ◽  
ÁLVARO V. N. de C. TEIXEIRA ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Stainless Steel ◽  
Food Industry ◽  
Antimicrobial Activities ◽  
New Method ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Antimicrobial Effects ◽  
Log Reduction ◽  
Steel Surfaces

Given the increasing number of antibiotic-resistant bacteria and the need to synthesize new antimicrobials, silver has attracted interest in the scientific community because of its recognized antimicrobial activity. This study aimed to evaluate the antimicrobial effects of silver nanoparticles (NP) obtained by a new method and tested at concentrations of 6 μg/ml and 60 μg/ml against the species Staphylococcus aureus, Listeria innocua, Salmonella Choleraesuis, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus. The ability of these nanoparticles to remove or kill vegetative cells adhered to stainless steel surfaces was also evaluated. We observed that the NP obtained with the new method, concentrated silver nanoparticles (CNP), and silver nanoparticles with added sodium chloride (NPNaCl) had high antimicrobial activities (P < 0.05). We also verified that the most effective condition for the removal of P. aeruginosa cells on stainless steel coupons (10 by 10 mm) was immersion of the surfaces in CNP. The CNP treatment produced a 5-log reduction of the microbial population after 30 to 60 min of immersion. The CNP treatment also performed better than water and sodium carbonate, a compound commonly applied in clean-in-place procedures in the food industry, in removing adherent B. cereus cells from stainless steel cylinders. Therefore, these results suggest that NP synthesized by a new procedure may be used as antimicrobials in the food industry, for example, for the sanitization of utensils that come into contact with foods.

scholarly journals Reactive Oxygen Species and low-dose effects of tritium on bacterial cells

2019 ◽  
Vol 208-209 ◽  
pp. 106035 ◽  
Author(s):  
Tatiana V. Rozhko ◽  
Evdokiya I. Nogovitsyna ◽  
Gennady A. Badun ◽  
Aleksandra N. Lukyanchuk ◽  
Nadezhda S. Kudryasheva
Keyword(s):  
Reactive Oxygen Species ◽  
Low Dose ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Dose Effects ◽  
Low Dose Effects

scholarly journals Enhancement in the antibacterial activity of cephalexin by its delivery through star-shaped poly(ε-caprolactone)-block-poly(ethylene oxide) coated silver nanoparticles

2020 ◽  
Vol 7 (10) ◽  
pp. 201097
Author(s):  
Sana Rahim ◽  
Samina Perveen ◽  
Shakil Ahmed ◽  
Muhammad Raza Shah ◽  
Muhammad Imran Malik
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Ethylene Oxide ◽  
Inhibitory Concentration ◽  
Bacterial Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
Biofilm Destruction ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The antibacterial activity of silver nanoparticles (AgNPs) stabilized with a four-armed star-shaped poly(ε-caprolactone)-block-poly(ethylene oxide) copolymer [St-P(CL-b-EO)] and its application as a drug delivery vehicle for cephalexin (Cp) was evaluated against pathogenic Staphylococcus aureus . The prepared AgNPs were characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, zeta sizer and atomic force microscopy (AFM). The antibacterial efficiency of Cp is enhanced several-fold by its delivery through complexation with St-P(CL-b-EO)-AgNPs, monitored by microplate assay and biofilm destruction studies. Finally, the visual destruction of bacterial cells and its biofilms by employing Cp and its conjugates at their minimum inhibitory concentration (MIC 50 ) and minimum biofilm inhibitory concentration (MBIC 50 ), respectively, is observed by topographic imaging by AFM. Enhanced antibacterial activity of St-P(CL-b-EO)-AgNPs loaded Cp is attributed to penetrative nature of the drug cargo St-P(CL-b-EO)-AgNPs towards the bacterial cell wall.

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