Showing 12 results for Nanoparticles
Doudi M, Naghsh N, Heiedarpour A,
Volume 5, Issue 2 (10-2011)
Abstract
Abstract: Background and objectives: Antibiotic resistant to Antimicrobial agents is one of the most important concern in hospitals, which can lead to increased costs, treatment fails and mortality rates. The aim of this study was identification of Gram-negative bacilli resistant to extended-spectrum β-lactamase Enzymes (ESBLs) and determination of the effect of silver nanoparticles on them. Materials & Methods: of 276 clinical samples referred to three hospitals of Isfahan city, 186 gram negative bacilli were studied. To recognize ESBLs production, the bacilli was assessed by disk diffusion method and confirmed by DDT and Double Disk approximation Test. The ESBL producing bacteria were subjected to increasing concentrations (12.5, 25, 50,100,200,400 and 500 ppm) of silver nanoparticles, prepared in Tehran Nano Pars Company, and Inhibitory zone diameter was measured. Results: of 186 isolates, 140 (%75/3) are gram-negative bacilli producing ESBLs and 46 (24.7%) of them without this capability. Most of ESBLs bacteria are belonged to urine infections and the most prevalent bacterium is Klebsiella pneumonia. All samples are sensitive to the nano silver solution with density of 100 ppm. Enterobacter aerogenes (24 mm) and Pseudomonas aeruginosa (23mm) have the greatest Inhibitory zone diameter in the presence of 500 ppm of silver nanoparticles. Conclusion: It seems that silver nanoparticles have inhibitory effect on all studied gram negative bacilli. The inhibitory effect of silver nanoparticles against ESBL producing Gram negative bacteria is dose depended Keywords: Gram-negative bacilli, ESBLs, silver nanoparticles.
Noroozi , R, Mehdinezhad, Mh, Zafarzadeh A,
Volume 5, Issue 2 (10-2011)
Abstract
Abstract: Background and objectives: There is a great interest in photocatalytic oxidation of contaminants, using ZnO, in recent years. The main objective of this research was to study photocatalytic disinfection of E. coli bacteria as water microbial pollution index, using nano particles of ZnO and a UV lamp in a batch reactor. Material and Methods: In this study, the contaminated water sample was prepared through adding 102 and 103 E. coli bacteria per ml of raw water. The contaminated water entered the photocatalytic oxidation reactor and removal efficiency of E. coli bacteria in different conditions were studied, including pH (5.5, 7, and 9), time (10, 20, 30, 40, 50 and 60 mins), dose of nano particles ZnO (0.2,0.4,0.8 and 1 gr/l), number of bacterium (102 and 103 per milliliter) and voltage of UV-C lamp, 27 volts. Characterizations of ZnO nanoparticles were determined using scanning electron microscope equipped with Energy Dispersive X-ray Analysis (EDX) system and X-ray diffraction (XRD) method. Results: Photocatalytic process efficiency is enhanced by increasing reaction time and dose of nano particles ZnO in the presence of UV lamp irradiation. The results show that the best conditions for removal of 102 and 103 bacteria per milliliter are obtained from condition including pH of 7, reaction time of 30 mins, 0.8 gr/l doses of nano particles ZnO and 27-volt-UV lamp. Conclusion: The results indicate that the increase of reaction time and dose of nano particles ZnO, in the presence of radiation UV lamp, have the most significant effect on photocatalytic efficiency. Based on the results, photocatalytic can be promising method for removal of E. coli bacterium from drinking water. Keywords: Photocatalytic, E. coli, irradiation UV, ZnO nanoparticles, water treatment
N Naghsh, M Doudi, Z Safaeinejad,
Volume 7, Issue 2 (7-2013)
Abstract
Abstract
Background and objective: In recent years, the resistance of opportunistic fungal strains to commercially available antifungal agents has been increased. The serious side effects of these compounds on mammalian cells forced the researchers to search for new antifungal substances. Thus we decided to investigate the antifungal properties of silver nanoparticles against Aspergillusfumigatus.
Materials & Methods: To investigate the antifungal effect of the round silver nanoparticles with 10nm diameter against Aspergillusfumigatus, the diameter of colonies after 8 days as well as the number of colonies in different days was determined, using direct drop test. After that, to measure the Minimum Inhibitory Concentration (MIC) and Minimum Fungicide Concentration (MFC) values of silver nanoparticles and fluconazole, Micro Dilution Broth method was performed. At the end, the MIC and MFC values of silver nanoparticles were compared to MIC and MFC of fluconazole.
Results: The results obtained from direct drop test confirm that the silver nanoparticles can decrease the diameter of fungal colonies in dose dependent manner. The data of silver nanoparticles on the number of colonies in different days shows that the number of colonies increases up to sixth day and then becomes fixed. Based on the results of Micro Dilution Broth method, the MIC and the MFC values of this component are 31.25 and 62.5ppm, respectively.
Conclusion: The present study confirms that silver nanoparticles with 10nm diameter have antifungal activity against Aspergillus fumigates.
Key words: Silver nanoparticles, Aspergillusfumigatus, Antifungal activity.
Sadeghian, M, Habibipour, R, Asghar Seif,
Volume 9, Issue 2 (7-2015)
Abstract
Background and Objectives: Due to the unique absorption and antibacterial properties of nanoparticles, their use in water and wastewater treatment to remove bacteria is spreading. This research aimed to study the effect of silver nanoparticles in the removal of Enterococcus faecalis isolated from industrial sewage.
Material and Methods: after preliminary studies, field studies including sampling of industrial wastewater was conducted. First, Fecal Coliform, total coliform and Enterococcus faecalis of industrial Sewage were measured by standard methods of microbiology, then the effect of concentrations of 500, 250, 125, 62.5, 31.25, 15.62, 7.81, and 3. 9 PPM of isolated nanoparticles serial dilution method on Enterococcus faecalis and standard (PTCC 1339) was determined. Next, and the turbidity of tube (OD), which represents growth of bacteria, was read at 600 nm with a spectrophotometer. After that, all tubes were cultured on solid medium and the results were analyzed using SPSS 22.
Results: fecal and total coliform contamination of industrial Sewage from slaughter and textile plant were approved and Enterococcus faecalis was isolated. The growth of isolates and standard bacteria was not controlled by any of these concentrations. None of the concentrations was able to remove the bacteria but the increase of concentration led to higher effect of nanoparticles, and in accordance with the type of bacteria, it was different, but the difference was not statistically significant.
Conclusion: Although silver nanoparticles ,according to the concentration, affect the Streptococcus faecalis, they cannot completely remove bacteria. Therefore, the economic factors and other involved factors need to be considered in the application of nanoparticles.
Keyword: Silver nanoparticles, Enterococcus faecalis, industrial Sewage
Shirin Sheikholeslami , Seyed Mahdi Rezayat , Reza Hosseini Doust , Hamid Reza Ahmadi Ashtiani ,
Volume 10, Issue 1 (1-2016)
Abstract
Abstract
Background and Objective: The spread of drug resistance in bacteria have prompted researchers to seek suitable alternative for antimicrobial drugs among various medicinal plants and nanoparticles. The aim of this study was to evaluate the effect of silver nanoparticles alone and in combination with methanol extract of Zataria multiflora on five Gram-positive and Gram-negative bacteria.
Methods: Different concentrations of the nanoparticles and extract alone or in combination with each other were tested against the bacteria, using well diffusion method. Three concentration levels (lowest, average and highest) were prepared form the nanoparticles and the extract for the combination, and finally nine different combinations were prepared.
Results: The extract and nanoparticles showed inhibitory effects against all the tested bacteria. The maximum diameter of growth inhibition zone in the presence of the extract and nanoparticles were observed in Streptococcus pyogenes (35.6mm) and methicillin-resistant Staphylococcus aureus (20.6mm), respectively. The maximum diameter of growth inhibition zone for the combination was measured in S. pyogenes (31mm).
Conclusion: The combination of low concentrations of the plant extract and nanoparticles are more effective against bacteria, but the combination of their high concentrations reduce the antibacterial effects in some cases.
Shima Doostmohammadi , Babak Kheirkhah , Seyed Mohammad Reza Khoshroo ,
Volume 10, Issue 4 (7-2016)
Abstract
ABSTRACT
Background and Objectives: Size of silver nanoparticles synthesized by ethanol and Bacillus lichenioformisis 20 nm and 15 nm, respectively. Nanoparticles can be used in treatment of several diseases. Chemical and biological methods have been used to synthesize silver nanoparticles. The aim of this study was to compare the size, shape and coating of silver nanoparticles synthesized by the chemical and biological methods.
Methods: Ethanol was used in the chemical reduction method and B. licheniformis was used in the biological method. Physical evaluation (salt test), absorbance measurement at 450 nm and imaging by transmission electron microscopy were performed to compare nanoparticles in terms of size, shape and coating.
Results: Observed maroon color, maximum absorption at 400-450 nm range and electron microscopy images confirmed the presence of nanoparticles. The shape of nanoparticles synthesized by the two methods was spherical. However, biosynthesized nanoparticles were smaller and had protein coating.
Conclusion: Given the smaller size of biosynthesized nanoparticles and presence of coating confirmed by the electron microscopy images, biosynthesis is recommended because of enhanced nanoparticles properties and reduced toxicity.
Keywords: Nanoparticles, Coating, Toxicity.
Mina Parsa , Malahat Ahmadi , Habib Dastmalchi , Aliasghar Tehrani ,
Volume 11, Issue 6 (11-2017)
Abstract
ABSTRACT
Background and Objectives: Nowadays, the prevalence of multidrug-resistant pathogens such as
Pseudomonas aeruginosa is increasing worldwide. Many studies have been seeking new treatment strategies to treat infections caused by these microorganisms. Silver nanoparticles (AgNPs) along with L-arginine have significant antimicrobial effects and could be used as alternatives for ineffective drugs.
Methods: In this study, the antibacterial activity of AgNPs, L-arginine and various concentrations of AgNPs along with L-arginine (12.5 and 25 mg/ml) were investigated against
P. aeruginosa PAO1 using the broth macrodilution method.
Results: Minimum inhibitory concentration of AgNPs, L-arginine and AgNPs combined with 25 and 12.5 mg/ml L-arginine was 15.6 μg/ml, 25 mg/ml, 1.9 μg/ml and 3.9 μg/ml, respectively. Minimum bactericidal concentration of AgNPs, L-arginine and AgNPs combined with 25 and 12.5 mg/ml L-arginine was 31.2 μg/ml, 50 mg/ml, 3.9 μg/ml and 7.8 μg/ml, respectively.
Conclusion: Our study suggests that AgNPs along with L-arginine can be used as an alternative antibacterial agent against
P. aeruginosa, and might be useful for treatment of wound infections.
Keywords: Nanoparticles, Arginine,
Anti-Bacterial Agents,
Pseudomonas aeruginosa.
Hamidreza Pordeli, Hadi Shaki, Ania Ahani Azari, Muhammad Sadeqi Nezhad ,
Volume 12, Issue 4 (7-2018)
Abstract
ABSTRACT
Background and objectives: Silver nanoparticles (AgNPs) are major nanomaterials with a variety of applications. The synthesis of nanoparticles by conventional methods is challenging and often requires use of hazardous chemicals. Therefore, there is a growing need for development of environmentally and economically friendly processes for the synthesis of nanoparticles. This study aimed at biosynthesis of AgNPs using a filamentous fungus; Fusarium solani.
Methods: Twenty-four Fusarium isolates were found from several soil samples collected from depth of 1-10 cm. All isolates were identified as F. solani based on morphological characteristics. The synthesis of nanoparticles were evaluated after 24, 48, 72 hours of culture. AgNPs were characterized using UV-visible spectroscopy and transmission electron microscopy.
Results: The synthesized AgNps showed maximum absorbance peak at 420 nm after 72 hours. Moreover, most AgNps were spherical with diameter of between 20 and 40 nm.
Conclusion: In this study, we introduced a simple biological process for biosynthesis of AgNPs using F. solani isolates from soil samples. The results indicate that fungi may be suitable for safe and cost-effective production of AgNPs.
Keywords: Fungi; Fusarium; Nanoparticles; Nanotechnology.
Fateme Golipour, Reza Habibipour, Leila Moradihaghgou,
Volume 13, Issue 6 (11-2019)
Abstract
ABSTRACT
Background and Objectives: Candida albicans is one of the most common fungal pathogens that can form biofilm, particularly on surface of medical devices. In recent years, C. albicans has shown increased resistance to antifungal agents. In this experimental study, we aimed to study effects of superparamagnetic iron oxide nanoparticles (Fe3O4 nanoparticles or SPION) on biofilm formation by C. albicans.
Methods: First, the SPION were synthesized by chemical co-precipitation. The formation of nanoparticles was confirmed by Fourier-transform infrared spectroscopy and X-ray diffraction. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of SPION were determined. Then, antibiofilm effects of the nanoparticles were investigated by enzyme-linked immunosorbent assay. Finally, data were analyzed using SPSS 22.0 at significance level of 0.05.
Results: According to the results of X-ray diffraction, the SPION had a mean diameter of about 70 nm. MIC and MFC values of SPION against C. albicans were 100 ppm and 200 ppm which reduced biofilm formation by 87.2% and 100%, respectively. SPION showed significant inhibitory effects on C. albicans growth and biofilm formation.
Conclusion: Based on the findings, SPION may be considered as a novel family of fungicidal compounds. However, further studies are necessary to evaluate the safety of these nanoparticles for treatment of fungal infections in humans.
Keywords: Candida albicans; Biofilms; SPION; Nanoparticles.
Azadeh Abedzadeh Hajar, Mohammad Dakhili, Mojgan Saghazadeh, Seyyed Soheil Aghaei, Razieh Nazari,
Volume 14, Issue 3 (5-2020)
Abstract
Background and Objective: The prevalence of the infections caused by Candida species has led to a significant increase in their resistance to antifungal compounds. The aim of this study was to i) investigate drug resistance ii) evaluate the incidence of Candida albicans drug resistance pattern in the vaginal samples of women referring to health centers of Qom province, and iii) examine the effect of Zn nanoparticles combined with fluconazole against C. albicans isolates.
Methods: This experimental, descriptive study was performed on 120 patients of candidiasis. In order to identify Candida albicans, direct experiments, differential culture, Germ tube test and sugar assimilation test (API20C kit) were conducted. The effect of different antifungal drugs and zinc nanoparticles and the synergistic effect of fluconazole with zinc nanoparticles were investigated by disk diffusion method. Minimum Inhibitory Concentration (MICs) of all cases was further specified.
Results: Of the 120 samples, 50 (41.6%) were identified as Candida albicans. These strains were resistant to certain antifungal drugs while others were semi-sensitive and sensitive. The lowest and the highest mean diameter of inhibition zone in all Candida albicans isolates belonged to ketoconazole (15.64 mm) and fluconazole nano-ZnO (26.76mm), respectively. The lowest and the highest MICs were observed in fluconazole- nano-ZnO and nano-ZnO, respectively.
Conclusion: The synergistic effect of Zn nanoparticles with fluconazole can be conducive to the treatment of vaginal candidiasis.
Mohammad Hassan Jokar, Fatemeh Mohamadkhani, Maliheh Moradzadeh, Samira Beygi, Ashraf Mohamadkhani,
Volume 16, Issue 2 (3-2022)
Abstract
Background and objectives: Recycled polyethylene terephthalate (RPET) nanofibers have become an important part of human life, with a continuous increase in their production and consumption. Herein, the antibacterial activity of nickel nanoparticles/recycled polyethylene terephthalate nanofibers (NiNP/RPET NF web) was evaluated by analyzing alginate expression in Pseudomonas aeruginosa, as an opportunistic microorganism.
Methods: NiNPs were synthesized and NiNP/RPET NF was produced by adding 25 μg/ml of NiNP to 10% solutions of RPET at a weight ratio of 3%. After exposing P. aeruginosa (PA01) to NiNP/RPET NF, the biofilm-forming capacity was determined and real-time PCR was performed to measure algD expression.
Results: Treatment with 25 μg/ml of NiNP/RPET NF reduced growth of P. aeruginosa on Mueller Hinton agar but did not result in complete inhibition. The biofilm optical density (550 nm) was 0.464 ± 0.021 after treatment with NiNP/RPET NF and 0.082± 0.011 in the absence of NiNP/RPET NF. This indicates the significant reduction of biofilm formation after exposure to NiNP/RPET NF (p=0.01). In addition, a 0.6-fold (p=0.03) reduction in alginate expression was detected by real-time quantitative real-time PCR.
Conclusion: Our results indicate the potential of NiNP/RPET NF for application in nano-based antibacterial medical systems.
Mahnoosh Fatemi, Fereshte Ghandehari , Danial Salehi, Parastoo Torabian,
Volume 17, Issue 6 (11-2023)
Abstract
Background: Discovering new cytotoxic compounds has received significant attention due to the rise in drug resistance and the adverse effects associated with chemotherapy drugs. In this study, the cytoplasmic extract of Lactobacillus casei was used to produce iron oxide nanoparticles (Fe2o3 NPs), and the cytotoxic effects of NPs were investigated on MCF-7 and human embryonic kidney 293 (HEK-293) cells.
Methods: The cytoplasmic extract of L. casei was mixed with 103M iron sulfate solution and incubated for 3 weeks at 37 °C and 5% CO2. The coprecipitation method was used to synthesize chemical Fe2o3 NPs. The synthesis of NPs was studied by electron microscopy and X-ray diffraction (XRD) analysis, and the cytotoxic effects were evaluated with dilutions (10, 100, and 1000 µg/mL) on MCF-7 and HEK cells.
Results: X-ray diffraction analysis and scanning electron microscopy presented the mean of NPs synthesized by the green method to be about 15 nm and their shape to be spherical, as well as the average of chemically synthesized NPs to be about 20 nm with cubic structure. Chemical and green synthesized NPs only at a concentration of 1000 µg/mL were able to significantly reduce the survival rate of normal HEK-293 cells; chemically synthesized NPs decreased MCF-7 cell survival only at 1000 µg/mL and green synthesis at 100 µg/mL and 1000 µg/mL.
Conclusion: Generating Fe2o3 NPs is biologically safe using the green synthesis method and the cytoplasmic extract of L. casei, which may be a suitable candidate for the treatment of cancer cells.
