Microbiology
Hanieh Bayat; Reza Habibipour; Narges Ghobadi; Fatemeh Golipour
Volume 28, Issue 5 , November and December 2021, , Pages 713-727
Abstract
Introduction: Staphylococcus epidermidis is an opportunistic pathogen and of the most important cause of infectious diseases. The prevalence of these infections, as well as the increase of antibiotic-resistant species, has become a solicitous issue. Using nanoparticles to combat bacterial infections ...
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Introduction: Staphylococcus epidermidis is an opportunistic pathogen and of the most important cause of infectious diseases. The prevalence of these infections, as well as the increase of antibiotic-resistant species, has become a solicitous issue. Using nanoparticles to combat bacterial infections can replace antibiotics. In this study, the antibacterial properties of doped silver nanoparticles on Iron oxide nanocrystal on isolated Staphylococcus epidermidis bacteria from nosocomial infection was studied.
Materials and Methods: Firstly, Nanoparticles were prepared by chemical co-precipitation method and were prepared at concentrations of 0, 20, 40, 60, 80 and 100 ppm to determine bactericidal properties. The effect of nanoparticles on isolated and standard strains of Staphylococcus epidermidis at 24, 48 and 72 hours were investigated by microplate titer. Data were analyzed by SPSS -18 software at a 0.01 margin of error.
Results: The results showed that time, bacterial type and concentration factors had a significant effect on the growth inhibition of Staphylococcus epidermidis, though the concentration and type of bacterial variables had more significant effects. The most antibacterial effect of doped silver nanoparticles on iron oxide nanocrystals was at 100ppm concentration over a 48-hour time on standard isolate.
Conclusion: Doped Silver nanoparticles on Iron nanocrystals affect the growth of Staphylococcus epidermidis and reduce its growth rate. This effect, in comparison to the effects of silver nanoparticles in a single state, which has already been investigated by researchers, is far more advanced and the combination of Metal nanoparticles together cause to improve their effectiveness.
Biotechnology & nanotechnology
fereshteh jookar kashi; Zohreh Boroumand
Volume 28, Issue 1 , January and February 2021, , Pages 144-155
Abstract
Introduction: The bacteria with a remarkable ability to regenerate heavy metal ions are considered biological factories or important nano-factories to produce nanoparticles. The bacterial production of nanoparticles as a green and one-step method can overcome production problems and disadvantages through ...
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Introduction: The bacteria with a remarkable ability to regenerate heavy metal ions are considered biological factories or important nano-factories to produce nanoparticles. The bacterial production of nanoparticles as a green and one-step method can overcome production problems and disadvantages through physical and chemical methods. Materials and Methods: In this study, bacteria isolates were taken from soil samples of Nakhlak mine. One silver resistant bacterial strain was selected for the production of silver nanoparticles. This strain synthesized silver nanoparticles with supernatant and biomass. The nanoparticles synthesized were characterized using XRD and SEM. The antimicrobial activity of the nanoparticles was determined. Results: The silver resistance bacteria were isolated from soil samples. One silver resistant bacterial strain was selected for the production of silver nanoparticles. The nanoparticles showed good antimicrobial activity against standard strains of tested microorganisms. Conclusion: The nanoparticle synthesized by bacterial strain isolated from Nakhlak mine is a promising new biological source for synthesizing silver nanoparticles with potent antimicrobial activity. According to the results, this compound can be used to make disinfectants
Biotechnology & nanotechnology
Akbar Safipour Afshar; fateme Saied Nematpour
Volume 27, Issue 4 , November and December 2020, , Pages 550-558
Abstract
Introduction: Green synthesis of silver nanoparticles is a simple and low-cost method. In addition, finding new therapeutic effects for silver nanoparticles is considered as an attractive field in cancer research. In the present study, synthesis of silver nanoparticles was performed by aqueous leaf extract ...
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Introduction: Green synthesis of silver nanoparticles is a simple and low-cost method. In addition, finding new therapeutic effects for silver nanoparticles is considered as an attractive field in cancer research. In the present study, synthesis of silver nanoparticles was performed by aqueous leaf extract of barberry. The effects of Ag nanoparticles were evaluated on cell viability and expression levels of ODC1 gene of the human breast cancer cell line (MDA-MB-231).
Materials and Methods: The synthetic nanoparticles were analyzed by UV-vis spectrophotometry and Transmission Electron Microscopy. The cultured cancer cells were treated under different concentrations of synthesized nanoparticles.The viability of the cells was analyzed by MTT assay and relative expression of ODC1 gene by Real-Time PCR.
Results: TEM photomicrographs showed that the spherical silver nanoparticles have been synthesized with an average size of 16 nm. The results showed cytotoxicity of silver nanoparticles in a time and dose-dependent manner. The average IC50 calculated was 16.48 µg/ml. The results also showed that silver nanoparticles decreased ODC1 gene expression levels about 4 folds at 20 µg/ml nanoparticles compared to control.
Conclusion: It seems that green synthesized silver nanoparticles through the gradual release of silver ions in the acidic environment of the cancer cells and production of oxygen radicals, as well as reduction of ODC1gene expression cause diminish of cancer cell viability.
Microbiology
behboud jafari; Alireza monadi sefidan
Volume 27, Issue 2 , July and August 2020, , Pages 163-171
Abstract
Background and Objective: In recent years, the drug resistance and side effects of antimicrobial drugs have increased in the treatment of infections. Therefore, the use of new herbal medicines with less side effects and nanotechnology in the medical arena can be a great help in treating these types of ...
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Background and Objective: In recent years, the drug resistance and side effects of antimicrobial drugs have increased in the treatment of infections. Therefore, the use of new herbal medicines with less side effects and nanotechnology in the medical arena can be a great help in treating these types of infections. The purpose of this study is to compare the effects of silver nanoparticles and methanolic extracts of Calendula officinalis on four strains of pathogens bacterial .Materials and Methods: In this descriptive-laboratory study, the plant was identified as a plant of C.officinalis, based on herbological characteristics in the Herbarium section of Azad University, Ahar Branch. In this study, the antimicrobial effects of methanolic extract of C.officinalis were studied by Soxhlet extractor method at concentrations of 20 mg / ml to 400 mg / ml of methanolic extract and 10 to 80 μg / ml concentrations of silver nanoparticles. Then, their antibacterial effects were investigated using well-diffusion and dilution methods.Results: The findings showed that methanolic extract of C.officinalis prevents the growth of S.aureus, B.cereus and E.coli. While the inhibitory effect of silver nanoparticles on P.aeruginosa and E.coli bacteria is more than gram-positive bacteria. The effect of the combination of C.officinalis extract and silver nanoparticles was much greater than the effect of each of them.Conclusion: The results showed that the flower extract of the C.officinalis has an antibacterial effect. Therefore, this extract can be a good option for future studies in In Vivo to provide antibacterial drugs.
Nasrin Mollania; Farangis Gharibnia; Ramin Rostami- Taghi Dizaj; Mitra Kheyrabadi
Volume 23, Issue 2 , March and April 2016, , Pages 214-221
Abstract
Background: With the advent and increasing microbial organisms that resistant to multiple antibiotics, as well as the necessity of decrease the cost of health care, the production of broad range of anti-microbial materials has become unavoidable for human societies. In this study, we synthesized the ...
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Background: With the advent and increasing microbial organisms that resistant to multiple antibiotics, as well as the necessity of decrease the cost of health care, the production of broad range of anti-microbial materials has become unavoidable for human societies. In this study, we synthesized the silver nanoparticles using bacterial α-amylase enzyme and evaluated the antibacterial properties of this eco-friendly nanoparticles. Methods: Silver nanoparticles were synthesized biologically using bacterial α-amylase enzyme, then the effects of antibacterial nanoparticles synthesized in LB medium containing various strains of pathogenic bacteria were investigated and then the minimal inhibitory concentration was calculated. Results: Nanoparticles produced by this method, based on DLS and SEM analysis, have the size of 20-40 nm and have good activity against Gram-positive bacteria and gram negative pathogenic bacteria. In the 200 of Ag-NPs, the all of pathogenic bacteria was killed. Conclusion: Biological nanoparticles synthesis relative to other physical and chemical methods has lower cost and higher durability (1). Due to good antibacterial activity of silver nanoparticles, this material has good medical applications.