Showing 23 results for Nanoparticles
F Barzegary, A Javed, S Rezaei Zarchi ,
Volume 18, Issue 1 (4-2010)
Abstract
Introduction: Organic antibacterial materials have been used as insecticides and bactericides for many years. Unfortunately, high temperatures in manufacturing process reduce their antibacterial properties. However, inorganic materials of antibacterial agents have excellent bacterial resistance and thermal stability. Over the past few decades, inorganic nanoparticles whose structures exhibit significantly novel and improved physical, chemical and biological properties and functionality due to their nano-scale size have elicited much interest.
methods:The aim of this study was to investigate the antibacterial properties of one kind of nano-specimen (TiO2 nanoparticle) against Escherichia coli and Streptococcus aureus. Our study was research perusal. In the first study, the optical density of E. coli and S. aureus cultures were observed in the presence of 0.01%, 0.75% and 1.5% of TiO2. In the second study, 6.3 log CFU/ml of E. coli and S. areus were separately exposed to 1.5% TiO2 at 37 ºC in water. In third study, we studied thew growth of E.coli in solid medium with and without nanoparticles.
Results: The presence of 0.01% TiO2 nanoparticles didn’t have a statistically significant effect, but in the presence of 0.75% and 1.5% nanoparticles, the bacterial colonies decreased significantly. In the control group, bacterial cells survival was nearly 13 days, while complete cell death of E. coli was seen when 1.5% TiO2 was applied for 24 hours. The same experiment for S. aureu, showed that complete cell death occured when the bacterial culture was exposed to 1.5% TiO2 for 16 hours.. It was shown that presence of 1.5% TiO2 in the solid medium suppressed the growth of E. coli 5.6 times more (p < 0.001).
Discussion: Our findings showed antibacterial effects of TiO2 nanoparticles against both bacteria, but S. areus bacteria were more sensitive to nanoparticles as compared to E. coli bacteria
S Rezaei Zarchi ,
Volume 19, Issue 5 (12-2011)
Abstract
Introduction: Considering the development of nanotechnology and extensive use of nano-materials are in different fields of industry, it is necessary to investigate their destructive effects on biological systems. Titanium dioxide(TiO2) is used in the production of different dyes, cosmetics, ceramics, photocatalysts, water and sewage treatment and a lot of other products. In the present study, the effect of TiO2 on the number of blood cells and the activity of liver enzymes of rat was assessed.
Methods: Concentrations of 50, 100 and 500 mg/Kg TiO2 nanoparticles (25 nm size) in distilled water were administered orally to Wistar rats for 14 days and some blood factors were studied on the blood samples collected.
Results: Results showed that TiO2 nanoparticles cause different changes in blood cells, and the changes were significant for some of them such as white blood cells (lymphocytes, monocytes, eosinophils and basophils). Decreased number of red blood cells and increased level of liver enzymes was also observed after the administration of different concentrations of TiO2, which proves the toxic effects of TiO2 on the body.
Conclusion: Results of the present study proved the toxicity of TiO2 nanoparticles on the living organisms. So, further studies are recommended to predict TiO2 toxicity.
A Barkhordari, S Barzegar, H Hekmatimoghaddam, A Jebali, H Fallahzadeh,
Volume 20, Issue 1 (5-2012)
Abstract
Introduction: Regarding the increasing use of silicon dioxide nanoparticles in medical biotechnology and probable side effects and diseases resulting from its usage, this study was performed to assess the toxic effects of different concentrations of SiO2 nanoparticles on human blood mononuclear leukocytes using the MTT assay.
Methods: In this laboratory trial study, we prepared suspensions of blood mononuclear cells from 10 young healthy men and also different concentrations of the nanoparticles (1, 10, 100, 500, 1000 and 1500µg/mL). The cells were then incubated with these nanoparticles for 24 hours at 37 °c, and finally the percent of dead cells were measured by MTT assay kit using spectrophotometer reading at 490 nm after 6 and 24 hours of incubation. Positive and negative controls and blanking were applied, too.
Results: A significant difference was found in percent of dead cells between the different concentrations of SiO2 nanoparticles and also between the exposed cells and control group (p<0.05). There was increasing cytotoxicity in 6 hours as well as 24 hours exposure with higher concentrations of the nanoparticles. Cytotoxicity after 24 hours exposure to 10 µg/mL of nanoparticles was about 6 times that of the 1 µg/mL.
Conclusion: This study showed for the first time that SiO2 with a concentration of 1 µg/mL has cytotoxicity on human blood mononuclear cells. Cytotoxic effects of this nanoparticle are time- and concentration-dependent.
M Zabihzadeh, S Arefian,
Volume 21, Issue 5 (12-2013)
Abstract
Introduction: Irradiation of loaded tumor with high-Z nanoparticles with low energy photon of 192Ir source during brachytherapy increases absorbed dose of tumor due to increase in possibility of photoelectric phenomena. Therefore, this study aimed to investigate dose enhancement due to nanoparticles (NPs) with different atomic numbers and concentrations as well as effect of NPs distribution (uniform & non- uniform) on dose enhancement.
Methods: Dosimetric parameters of HDR-192Ir source (MicroSelectron model) were calculated by MCNP-4C code on the basis of recommendations of AAPM, TG-43. A tumor (1 cm3) loaded with uniform and non-uniform distribution of 7, 18 and 30 mgr/gr of 79Au, 64Gd, 26Fe and 22Ti in water phantom (30×30×30 cm3) was simulated.
Results: DEF of 4.7% to 19.4% and 3.3 to 18.6% were calculated respectively for uniform distribution of 79Au and 64Gd with 7 to 30 mgr/gr concentrations. For non-uniform distribution these values were 0.4%to 1.9% and 0.2% to 1.2%, respectively. Increased dose of the peripheral-health tissue due to presence of 2 to 8.5 mgr/gr of 79Au and 64Gd was estimated from 1.3% to 6.5% and 1.1% to 4.2%, respectively.
Conclusion: increase of atomic number and concentrations of NPs enhance the absorbed dose due to increased possibility of photoelectric phenomena. Non-uniform distribution of NPs underestimated dose compared to uniform distribution therefore, considering accurate NPs distribution inside the tumor volume is crucial to calculation of dose enhancement. Targeted labeling of NPs for the maximum absorption by tumor and for the minimal penetration into peripheral tissues has potential to increase radiation therapeutic ratio.
Mrs N Mazaheri, Dr A Karimi, Dr H Salavati, Dr S Rezaei Zarchi, Dr S Khalilian, Mrs R Rezaei Ranjbar Sardari,
Volume 22, Issue 4 (10-2014)
Abstract
Introduction: In spite of increasing usage of metal nanoparticles, few studies have been conducted on their side effects, particularly under in-vivo conditions. Hence, the present study aimed to assess the effect of magnesium oxide nanoparticles (MgONPS) on the liver and kidney function of rats in vivo
Methods: Concentrations of 62.5, 125, 250 and 500 ppm of MgONPS (10-15 nm size) were intraperitoneally injected into rats, and then the liver and kidney function were investigated.
Results: The study results revealed that MgONPS caused different changes in liver enzymes. In fact, the AST and ALP values were significantly increased compared with the control group, whereas the levels of ALT, Urea and Creatinine did not demonstrate any significant differences. In addition, no histological disorders were observed in the kidney tissue, in contrary to liver tissue in which some alternations were observed such as apoptosis and proliferation of small bile ductules indicating damage of tissue in expose of high doses of MgONPS.
Conclusions: The study findings indicated that magnesium oxide nanoparticles in higher doses of
250 ppm can have toxic effects on the liver, therefore their toxicity should be considered, while applying them in different fields of industries.
N Mohammadi, M Mirhosseini, M Shirzad, A Dehghan Hamdan, N Yazdani,
Volume 23, Issue 4 (7-2015)
Abstract
Introduction: Biologists have increasingly used zinc oxide (ZnO) nanoparticles in regard with biological applications. The present study aimed to assess feasibility of ZnO nanoparticles synthesis by high-energy milling as well as to investigate their antimicrobial effect.
Methods: The high-energy ball milling technique was used to produce ZnO nanoparticles from micron-scale ZnO particles. The phase state, morphology, and size of the ZnO nanoparticles were characterized by different methods of particle size analyzer (PSA), X-ray diffraction (XRD), UV-Vis spectroscopy and transmission electron microscopy (TEM). Furthermore, the antibacterial effect of ZnO nanoparticles was examined on E. coli and S. aureus bacteria.
Results: The study results demonstrated that size of the synthesized nanoparticles was within the range of 20 -90 nm and their morphology was reported as nanorod and nanoparticles with multifaceted cross-section. An increase in the density of nanoparticles resulted in a rise in the antimicrobial effect. Moreover, Staphylococcus aureus bacteria inhibition zone was 3±0.5 and 7±0.5 mm respectively at the density of 6 and 10 mM. The MIC and MBC of ZnO nanoparticles provided for Staphylococcus aureus were observed 3±3 and 2.5±0 mg/ml, whereas they were reported 7.5±0 and 8±0 mg/ml for Escherichia coli bacteria.
Conclusion: The findings of the present study revealed that ZnO nanomaterials could be synthesized by applying high-energy milling on micron-scaled ZnO particles. In addition, they can be utilized in food packaging and preservation process.
M Fatemi, A Noori,
Volume 23, Issue 5 (8-2015)
Abstract
Background: Silver nanoparticles lie within the most commercialized nanoparticles due to their strong antimicrobial properties. Animal studies have recently indicated that silver nanoparticles can be transfered from mothers to their pups via the maternal milk. However, there seems to be scant information in regard with the toxicity of these nanoparticles on various organs within sensitive developmental stages. Hence, this study aimed to investigate the effect of silver nanoparticles on the developing liver of rat pups after maternal exposure(during lactation) to these nanoparticles.
Methods: The lactating mothers(30 rats) were divided into two groups. The treatment and control groups orally recieved nano particles(25 mg/kg BW) and deionized water(from 1st to 12th days of lactation), respectively. The pups were killed and their livers were collected, some of which were sliced and stained with Hematoxylin and Eosin. The concentration of Malondialdehyde, Glutathione, Glutathione peroxidase activity and silver level of the pups' livers were determined utilizing spectrophotometric assay and inductively coupled plasma mass spectrometry analysis, respectively.
Results: The study results demonstrated a significant increase in malondialdehyde and silver levels(p<0.001)as well as a significant decrease in Glutathione peroxidase activity(p<0.01) and Glutathione concentration(p<0.05) of the pups' livers in the treatment group compared with those of the control group. Moreover, histopathological examination indicated sinusoidal dilatation and congestion as well as fatty degeneration in the pups' livers of the treated group.
Conclusion: The study findings proposed that exposure to silver nanoparticles during lactation may induce toxicity in the liver of the pups, though further experiments are required in this field.
L Rahimzade Torabi , M Doudi, A Noori,
Volume 23, Issue 10 (1-2016)
Abstract
Introduction: The gold nanoparticles as other nanoparticles have catalytic, magnetic, optical, and biological (antimicrobial) properties. On the other hand, resistance to antibiotics is one of the greatest public health problems posed in the world. Therefore, the present study aimed to investigate the antibacterial effects of gold nanoparticles on multi-drug resistant klebsiella pneumoniae as well as escherichia coli and its effect on the liver of balb/c mice.
Methods: In this study, multi-drug resistant Klebsiella pneumoniae and Escherichia coli bacteria clinical samples were utilized that were isolated from several hospitals in Isfahan and then the toxic effects of nanoparticles were investigated on the Balb / C mice. Colloidal gold nanoparticles were also applied with spherical shape and a concentration of 200 ppm in size of 10 nm, using two wells and disk agar diffusion method. Antibacterial properties of the nanoparticles were evaluated within 1-3 days with 37 ˚c temperature, and diameter of inhibitory zone of growth was measured every day. Tissue and liver enzymes of the mice were examined, as well.
Results: The greatest diameter of inhibitory zone was detected in multi drug resistant E. coli. Most of the MIC and MBC were found in multi-drug resistant Klebsiella pneumoniae bacteria .Gold nanoparticles did not reveal any significant changes on the weight, liver enzymes and liver tissue of Balb / C mice after one month.
Conclusion: As the findings of the current study revealed, inhibitory effect of gold nanoparticles was observed on the axamined microorganism. Although the laboratories findings are promising, more studies should be conducted in regard with therapeutic standardization.
Ar Yazdanbakhsh, M Rafiee, H Daraei, H Kamali,
Volume 23, Issue 12 (3-2016)
Abstract
Introduction: Amoxicillin is one of the most important groups of pharmaceuticals that benefits humans and animals. However, antibiotics excertion in wastewaters and environment have emerged as a serious risk to the biotic environment, and their toxic effects can harm the organisms. Iron-based metallic nanoparticles have received special attention in regard with remediation of groundwater contaminants. In the typical nZVI-based bimetallic particle system, Fe acts as the reducing agent. Thus, the present study aimed to evaluate the synthesis and characteristics of nZVI in regard with degrading AMX.
Methods: In this study, nZVI nanoparticles were synthesized using the liquid-phase reduction method by EDTA as a stabilizer material. Structure and properties of nanoparticles were characterized by BET, SEM, XRD and EDX analysis. A multi-variate analysis was applied using a response surface methodology (RSM) in order to develop a quadratic model as a functional relationship between AMX removal efficiency and independent variables ( initial pH values, dosage of nZVI, contact time and amoxicillin concentration). The four independent variables of solution pH (2–10), AMX concentration (5-45mg/l), contact time (5-85 min) and nanoparticles dose (0.25 – 1.25 g) were transformed to the coded values.
Results: The study results demonstrated that more than 69 % of AMX was removed by nZVI. The optimal AMX removal conditions using nZVI were found as 1.25 g of nZVI, pH 4, contact time of 80 min and concentration of 30 mg/l.
Conclusions: The ability of nZVI in degradation of AMX revealed that these materials can serve as a potential nano material with respect to the environmental remediation.
J Baharara, M Motie, T Ramezani, Ar Iranbakhsh,
Volume 24, Issue 4 (7-2016)
Abstract
Background and purpose: Angiogenesis has a role in many vital processes also many developmental processes are influenced by an electromagnetic field. In the present study the synergic effects of silver nanoparticles and low-frequency electromagnetic field on angiogenesis in the chick embryo chorioallantoic membrane (CAM).
Materials and method: In this experimental study, (Ross strain ) on the eighth day incubation of embryonated chicken eggs were treated with 50, 100 and 200 mg/ml of silver nanoparticles. Then on tenth day, the eggs for 3 hours were exposed to the electromagnetic field. The twelfth day, the samples were photographed and the number, length of vessels, weight and Crown-rump were analyzed with software Image J. hemoglobin content were tested with derabkin assay. Silver nanoparticles antioxidant activity was assessment. Data were analyzed using spss 16 software and ANOVA statistical test.
Results: The average number and length of vessels and hemoglobin content decreased in treated groups with silver nanoparticles and Electromagnetic fields. synergic use of silver nanoparticles and Electromagnetic fields reduce the average number and length of vessels and hemoglobin content than using one alone. Antioxidant assay showed that silver nanoparticles inhibited free radical production.
Conclusions: Synergic application of biogenic silver nanoparticles with electromagnetic field significantly reduced angiogenesis CAM comparing to use one of them.
Mahdi Torabi Zarchi, Mahboubeh Mirhosseini,
Volume 24, Issue 11 (2-2017)
Abstract
Introduction: Nanoparticles (NPs) are one of the antibacterial substances, among them nanoparticles type MgO and Fe2O3 are less toxic to mammalian cells. So, the aim of this study was investigation of combination effects of iron oxide and magnesium oxide nanoparticles on the growth of Staphylococcus aureus and Escherichia coli (E.coli) to achieve the optimum combination of nanoparticles inhibit the growth of Staphylococcus aureus and Escherichia coli in food (juice).
Methods: In this experimental research, the effect of MgO and Fe2O3 Nanoparticles compound on Staphylococcus aureus and Escherichia coli bacteria in liquid environment was investigated, and then their effect was investigated separately in juices of carrot, pomegranate and apple via colony count approach. Also, scanning electron microscopy was used to characterize the morphological changes of Staphylococcus aureus and Escherichia coli after antimicrobial treatments. The results of the research were analyzed using one way ANNOVA.
Results: The results of the research indicated that in liquid medium, these nanoparticles lead to reduce the growth of both bacteria. compound of 1.5Mg+0.5Fe2O3 was introduced as the most appropriate antibacterial compounds; Staphylococcus aureus sensitivity to Escherichia coli was higher against nanoparticles. The findings of research about the juices revealed that the combined effect of nanoparticles reduced the growth of both bacteria. the combined effect of Fe2o3 and MgO nanoparticles treatments distorted and damaged the cell membrane, resulting in a leakage of intracellular contents and eventually the death of bacterial cells.
Conclusion: Nanoparticles in the allowed concentrations have significant effect on Staphylococcus aureus and Escherichia coli bacteria.
Mohammad Hossien Salmani , Mohadesah Mikaie , Homa Torabizadeh , Reza Rahmanian ,
Volume 25, Issue 4 (7-2017)
Abstract
Introduction: Because of their unique properties, magnetic nanoparticles have attracted the attention of many researchers in various fields. The stabilization enzyme on functionalized magnetic nanoparticles, with the maintenance of free protein activity and optimal stability, have been developed by various surface modification techniques. This review focused on the methods for modification of iron magnetic nanoparticles and their application to stabilize protein.
Methods: Among the published valid articles, 51 articles were selected from various scientific databases between the (2000-2016) years. The papers were evaluated for biological, physical and chemical synthesis methods, advantages and limitations of synthesis methods, application of surface modification and enzyme fixation on iron oxide nanoparticles. Precisely analyzing of papers, the most suitable method was investigated for the synthesis of nanoparticles and the use of nanoparticles was summarized in the biomolecules fixation process.
Conclusion: Co-precipitation method is an easy way to prepare magnetic nanoparticles of iron with a large surface and small particle size, which increases the ability of these particles to act as a suitable carrier for enzyme stabilization. Adequate modification of the surface of these nanoparticles enhances their ability to bind to biological molecules. The immobilized protein or enzyme on magnetic nanoparticles are more stable against structural changes, temperature and pH in comparison with un-stabilized structures, and it is widely used in various sciences, including protein isolation and purification, pharmaceutical science, and food analysis. Stabilization based on the covalent bonds and physical absorption is nonspecific, which greatly limits their functionality. The process of stabilization through bio-mediums provide a new method to overcome the selectivity problem.
Aidin Marzban, Bagher Seyedalipour, Manijeh Mianabadi, Ali Taravati,
Volume 25, Issue 5 (8-2017)
Abstract
Introduction: Nickel (Ni) and nickel compounds are widely used in industry, radiotherapy and nanomedicine. However, the toxicity of NiO nanoparticles is yet to be fully elucidated. In this study, we evaluated the toxicity of NiO and NiO nanoparticles (NiONPs) using basic medical diagnostic tools, such as biochemical tests and histopathological changes of liver in rats.
Methods: In this experimental study, 49 male rats were divided randomly into seven groups (n=7), including one control group and six experimental groups (three experimental groups received NiONPs and three experimental groups received NiO intraperitoneally) with doses of 10, 25 and 50 mg/kg for 8 days. After 8 days, blood samples were collected from heart and liver enzyme activity assay was performed on serum sample. Livert issue for histopathological evaluation were stained with hematoxylin and eosin. Data were analyzed using ANOVA and Tukey test with SPSS21 software at significant level of P<0.05.
Results:The results showed that enzyme activity of AST, ALT, ALP and LDH in different doses NiO NPs and NiO increased in compared to control group (p<0.05). Histopathological study of liver following intraperitoneal (IP) administration of NiONPs and NiO showed pathological changes, including congestion, Cirrhosis and inflammatory cell infiltration compared to control group.
Conclusion: The results of this study demonstrate that exposure to different doses of NiONPs and NiO can induce different degrees of damage in a dose dependent manner. Thus, increasing level of liver enzymes and histopathological changes confirmed NiONPs and NiO toxicity.
Elham Sasani, Hashem Shahi Malmir, Dr. Fatemeh Daneshmand, Mohammad Majdizadeh, Bibi Fatemeh Haghiralsadat,
Volume 26, Issue 6 (10-2018)
Abstract
Introdution: Chemotherapy is one of most effective methods to fight metastatic tumors. Its non- targeting has many side effects. The aim of this study was to investigate various formulations of Lipo-Niosomal hybrid system to achieve an optimized and targeted formulation to provide proper function as a complementary drug in cancer chemotherapy.
Methods: The present study was an experimental study. Five Lipo-Niosome systems with different formulations containing DPPC, Cholesterol, and Span60 were synthesized using thin-film method. Three formulations were chosen based on the entrapped efficiency of curcumin and their release profile was investigated in order to choose the final formula. In the following, the final formula was optimized by DSPE-mPEG(2000) and after calculating, the curcumin release profile in simulated environment of healthy and cancerous cells; physiochemical characteristics of the final formula determined by ZetaSizer, FTIR and SEM instruments.
Results: Final formulation of curcumin PEGylated lipo-niosome had 147.5 nm size, 98.12%±1.85 entrapment, -8.90 mV zeta potential, and 0.176 of PDI. The maximum release of the drug for this nanosystem in an environment similar to healthy cells was 19.02% and 24.88% in cancerous cells. FTIR and SEM investigations show drug and nanocarrier had no chemical interaction leading to change the functional groups and its particles have a spherical morphology.
Conclusion: The findings of this study along with confirming the system to be semi-targeting, shows that carrier released entrapped drug with continuous and controlled rate without any change in chemical nature of the drug. It appears the nanoscale size and the low anionic charge of the system is an indication of its high cellular uptake.
Nouraddin Abdi. G, Akram Astani, Mohammad Hosein Zare,
Volume 26, Issue 9 (12-2018)
Abstract
Introdution: Cerium oxide nanoparticles (CONPs or nanoceria) are used as radiation protection agent, a catalyst and an insulating layer on silicon substrates. The aim of this study was optimization of condition for cerium oxide nanoparticles dispersion with anionic surfactant sodium dodecyl sulfate (SDS) in deionized water.
Methods: This study was a cross-sectional descriptive. The dimensions, image and chemical composition of nanoceria were obtained using scanning electron microscopy (SEM). UV/VIS absorption spectrum of nanoceria suspension in the presence of SDS and Tween 20 surfactants were recorded and maximum absorption wavelength was determined.
Results: According to the SEM images taken in this study, the shape of a nanoceria was spherical, consisting of cerium with 97.9 wt% and oxide with 2.1 wt%. The dimensions of nanoparticles were determined 29.3 nm. UV/VIS maximum absorption was recorded at 318 nm. The mean sustained concentration of nanoceria suspension with 0.45 wt% of SDS had a significant increase than the presence of 0.05 wt%, 0.15 wt%, and 0.25 wt% of SDS (P-value = 0.001). An increase of 5 hours of sonication time resulted in a significant increase in the mean sustained concentration of nanoceria suspension (P-value = 0/000).
Conclusion: An anionic surfactant SDS with an optimum weight percentage of 0.45 can be used to increase the stability of the nanoceria distribution. Furthermore, increasing the sonication time for 5 hours can be a better alternative than increasing the weight percentage of anionic surfactant SDS to achieve a stable distribution.
Fatemeh Naghd Abadi, Bahman Vahidi,
Volume 29, Issue 1 (3-2021)
Abstract
Introduction: Hyperthermia is one of the noninvasive methods of treating cancer. In this method, heat can be generated in several methods. One of these methods is injecting magnetic nanoparticles as a solution into the tumor site and place it in a magnetic field.
Methods: The study was analytical one, modeling was performed using computational methods, and in vitro experimental data were used as the boundary conditions. The problem was solved with a geometry consisting of different layers of skin, adjacent tissue, tumor and injection site and assuming axial symmetry. The problem was solved with a geometry consisting of different layers of skin, the adjacent tissue, the tumor and the injection site and assuming axial symmetry. The effect of different injection sites, effect of performing two injections with a smaller volume comparing with an injection with a large volume, and finally the effect of the injected solution on the temperature distribution of the tumor was investigated.
Results: Results showed that injections with a smaller volume of solution in different sites would have better results, so that more parts of the tumor would reach to a temperature above 42°c, which is the temperature needed for having cancer cells died. Injection with the temperature of 37°c would be more effective than injection at room temperature and reached the desired temperature in less time.
Conclusion: According to the novelty of this investigation in assuming data from empirical experiments on the solution containing cobalt ferrite nanoparticles coated with polyethylene glycol as the boundary condition of the problem in modeling, the study is an important step in a more precise prediction of the clinical conditions occurring through using these methods of hyperthermia.
Mohammad Reza Madi, Mohammad Eslami-Kalantari, Zahra Ahmadi Ganjeh,
Volume 30, Issue 1 (4-2022)
Abstract
Introduction: The main goal of radiation therapy is destroying the tumor so that the surrounded healthy tissues have received the least amount of radiation at the same time. In recent years, the use of nanoparticles has received much attention due to the increasing effects they can have on the deposited dose into the cancer cells. The aim of this study was to investigate the effects of nanoparticles in improving radiotherapy conditions by Monte Carlo simulation.
Methods: In this study, the geometry that was considered as the tissue of the human body was designed by Monte Carlo simulation method and distributed nanoparticles such as gold, silver, platinum, etc. into the geometry. Then the source was placed in a coordinate of this geometry and by increasing the photons to this geometry, the Dose Enhancement Factor was calculated. The simulation was performed using MCNP Code.
Results: The results showed that platinum nanoparticles have a better performance in increasing the dose rate than other nanoparticles so that for photons with energy of 40 kV, this increase was approximately 2.5 times, also increasing the dose was directly related to increasing the concentration of nanoparticles.
Conclusion: Considering the sufficient biocompatibility and the degree of penetration in the target, the use of nanoparticles in radiotherapy is one of the most promising methods to increase the dose delivered to the target. Given that the cell model and the results presented in this work lead to a better understanding of the effects of the distribution of platinum nanoparticles in increasing the dose, these calculations are valuable.
Elahe Darvishi , Asra Amani, Somayeh Mirsadeghi, Behrang Shiri Varnamkhasti ,
Volume 30, Issue 3 (6-2022)
Abstract
Introduction: Photothermal therapy is a method of cancer treatment that plasmonic nanoparticles are used to convert infrared light into local heat. Due to the plasmonic properties of gold nanoparticles, this compound was used as a contrast agent. The aim of this study was to synthesize gold nanoparticles with different conjugations for photothermal therapy.
Methods: This research was an experimental study. The method used for the synthesis of spherical and rod gold nanoparticles in this research was the Seeding Method. The nanoparticles were then conjugated with various compounds such as rifampicin, quercetin and RGD. Then, the physical and chemical properties of nanoparticles were determined by DLS, UV-Vis and TEM methods. Cytotoxicity test was also performed on MCF-7 ((Michigan Cancer Foundation-7)) cell line. Cell viability was calculated using prism software. Differences were compared by analysis of variance (ANOVA) using SPSS version 16 software.
Results: In the UV test, two-peaked rod nanoparticles were observed in the range of 523 and 738 nm, and in the case of spherical nanoparticles at 535 wavelengths, which indicates the correct synthesis without impurities and with the appropriate size .In the cell test, a decrease in cell viability was observed compared to the control group. In the first 24 hours, spherical nanoparticles had the highest lethality to the point that at a concentration of 20 μg / ml, it had almost 50% lethality. In addition, after 48 hours at low concentrations, rod nanoparticles showed better results, so they were more suitable. By targeting these nanoparticles to specific cancer cells, in addition to being used to kill cancer cells, the effect of these nanoparticles on healthy cells can be prevented. By conjugating different compounds on the surface of these nanoparticles, cell uptake can also be increased and cancer cells can be killed using photothermal therapy.
Conclusion: According to the results obtained in this study, it seems that low-concentration of gold nano-rods are more suitable for photothermal therapy.
Mina Javadi, Hossein Soltani, Rasoul Shokri,
Volume 31, Issue 5 (8-2023)
Abstract
Introduction: Salmonella typhi is a large group of gram-negative bacilli with Enterobacteriaceae and common pathogens between humans and animals, which is the main cause of typhoid fever in humans. One of the most common antibiotics in the treatment of Salmonella is cotrimoxazole, but due to the widespread use of antibiotics, bacterial resistance has developed. The aim of this study was to investigate the antibacterial effect of silver nanoparticles and its combination with the antibiotic cotrimoxazole to produce a more effective antimicrobial drug against Salmonell typhi.
Methods: In this experimental study, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for silver nanoparticles and combination with cotrimoxazole, was performed based on microdilution method. Then, their antibacterial effects were investigated in infected mouse model. In order to analyze the results statistically, SPSS software version 16 was used. In this test, P< 0.05 was considered as a significant level.
Results: MIC and MFC of silver nanoparticles for Salmonella typhi were 4 ppm and 8 ppm respectively, composition of silver nanoparticles with cotrimoxazole for Salmonella typhi were 62 ppm and 125 ppm and cotrimoxazole for Salmonella typhi were 500 ppm and 1000 ppm. Mouse model to study the antibacterial effect of silver nanoparticles and combination with cotrimoxazole against Salmonella typhi infection was confirmed., Silver nanoparticles had the highest antibacterial effect and cotrimoxazole has the lowest antibacterial effect than other groups.
Conclusion: Silver nanoparticles are very effective compared to other groups, especially the antibacterial cotrimoxazole.
Mahnaz Mohammadi, Shirin Hafezi,
Volume 31, Issue 5 (8-2023)
Abstract
Introduction: Sea cucumber is one of the important aquatic animals that has many nutritional and medicinal properties and is of medical importance due to the presence of compounds with therapeutic and antibacterial effects. The purpose of this study was to investigate the antibacterial effect of selenium hybrid nanoparticles and sea cucumber extract on Escherichia coli, Micrococcus luteus and Bacillus cereus bacteria.
Methods: MIC evaluation method was determined for the cytotoxic effect of sea cucumber extract on microbial cells. To carry out this research, after collecting and extracting sea cucumbers, the cytotoxicity of this extract on microbial cells was determined using the MIC method. Then, the antibacterial effect of sea cucumber extract, selenium hybrid nanoparticle and the combined effect of sea cucumber extract and selenium hybrid nanoparticle on Escherichia coli, Micrococcus luteus and Bacillus cereus bacteria were evaluated. Statistical analysis was done using SPSS version 16 software.
Results: The results of the experiments showed that sea cucumber extract with different dilutions had an antibacterial effect on Escherichia coli bacteria, Micrococcus luteus and Bacillus cereus. These results also applied to the tests performed with selenium nanomedicine. Interestingly, after combining a certain amount of sea cucumber extract and selenium nanomedicine, a greater antibacterial effect was observed on the above-mentioned 3 bacteria.
Conclusion: The synergistic effect of sea cucumber extract and selenium nanoparticles has a higher level of antibacterial properties.
