جستجوی مقالات مرتبط با کلیدواژه « Copper Oxide Nanoparticles » در نشریات گروه « پزشکی »

Adding nanoparticles to dental composite resins, could reduce bacterial adhesion and secondary caries. Thermocycling can resemble in-vitro conditions to the oral environment. The aim of this study was to determine the effect of thermocycling on the microleakage of a mixture of copper oxide nanoparticles and flowable composite.

In this in-vitro study, 88 premolar teeth were divided into eight groups based on the application of copper oxide nanoparticles with concentrations of 0.1% and 0.3% w/w and thermocycling by 0, 1000, 5000 and 15,000 cycles. The occlusal grooves of the teeth were sealed with the mixture of flowable composite and copper oxide nanoparticles, and the teeth were thermocycled. Next, the teeth were immersed in methylene blue 2% solution for 24 hrs and were cut and the microleakage was evaluated by a stereomicroscope (hp/USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney tests at the significance level of 0.05.

In the groups with 0.1 % copper oxide nanoparticles, the mean microleakage increased significantly with increasing the number of thermocycling rounds (P=0.032). The difference in the microleakage between the groups exposed to 0 and 15,000 termocycling was significant (P=0.019). However, thermocycling had no significant effect on the microleakage of groups with concentration of 0.3% (P=0.780). The specimens subjected to the 0, 1000, 5000 and 15000 thermocycling in two concentrations of copper oxide nanoparticles showed no significant difference in the microleakage.

In groups containing copper oxide nanoparticles with a concentration of 0.1%, the microleakage increased by increasing the number of thermocycling up to 15,000 cycles compared to the control group. However, this did not have significant effect for the concentration of 0.3% copper oxide nanoparticles.

Nanoparticles have been recently used in dentistry to improve the resin composite properties. In addition to its antimicrobial effect, copper oxide nanoparticles improve some of the resin composite properties. The durability of composite restorations is another matter. In this study, the effect of mechanical load cycling on the microleakage of the mixture of copper oxide nanoparticle and flowable composite was investigated.

In this study, 96 healthy premolar teeth were randomly divided into eight groups. Copper oxide nanoparticles with weight concentrations of 0.1% and 0.3% were added to the Z350 flowable composite, and occlusal pit and fissures were sealed. Mechanical loading cycling was performed with a force of 70 Newtons and repetition rates of 0, 50,000, 100,000, and 200,000 loads. The teeth were cut after staining with methylene blue, and the dye penetration was checked by a stereomicroscope and qualitatively scored. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests.

In both concentrations of nanoparticles, with an increasing number of load-cycling cycles, microleakage significantly increased. In the 0.1% group, the two-way comparisons of groups between 1 to 4, 1 to 3, and 2 to 4 and in the 0.3% groups between 5 to 7, 5 to 8, and 6 to 8 were significantly different. In the comparison of different concentrations to similar load cycling rates, there was no significant difference in the amount of microleakage.

Mechanical loading cycling increased the microleakage rate in both two concentrations when the frequency of load was higher than 50,000 loads. There was no difference in the microleakage rates of groups with different concentrations and similar load cycling. By increasing the concentration from 0.1% to 0.3%, microleakage did not increase significantly.

Copper oxide nanoparticles, in addition to useful applications, may have adverse effects on the organisms.This study was done to determine the effect of copper oxide nanoparticles on liver toxicity, enzymes changes and liver histological structure of rats.

In this experimental study, 40 Wistar male rats were randomly allocated into 4 groups. During 10 days, five times (one day interval), 3 groups of rats were received 10, 20 and 30 mg/kg of copper oxide nanoparticles with a diameter of less than 50 nm and purity of 99% and a surface of 80 m2/g intraperitoneally, respectively. One group was considered as the control group. Activity of Lactate dehydrogenase (LDH), Alkaline phosphatase (ALP), Aspartate transaminase (AST) and Alanine aminotransferase (ALT) enzymes were tested in two stages (one day and 15 days after treatment). Also, liver tissue sections were prepared and stained with hematoxylin-eosin.

No significant alterations of AST enzyme activity were not seen between different groups in two stages. The activity of ALT, ALP, and LDH enzymes in the first stage showed a significant increase in all treatment groups compared to control and returned to normal after 15 days. Rat's weight changes were not statistically significant between different groups. Histological studies revealed multiple tissue injuries in dose-dependent in treatment groups which included mild and severe hyperemia, hepatocytes degeneration, hyperplasia and inflammation.

Injection of low doses of copper oxide nanoparticles, after 15 days, although changes in enzyme activity return to normal, but significant disturbances observes in the structure of the liver tissue.

Copper oxide nanoparticles with unique properties have numerous biological applications with probably toxicity. This study was conducted to determine the toxicity of copper oxide nanoparticles on the pituitary-gonadal axis and spermatogenesis in male rats. In this experimental study, 40 male Wistar rats were randomly allocated into 4 groups including control group and three intervention  groups which receiving the cancentration of 10, 20 and 30 mg/kg of copper oxide nanoparticles 5 times intra-peritoneally, respectively. Blood sampling was collected first day and 15 days after the last injection. Level of testosterone, FSH and LH were measured by ELISA method. After anesthesia and dissection of mice in each group, tissue sections of testis were prepared and stained with hematoxylin-eosin. Morphological status of spermatogenesis process and counting of types of cells (spermatogonium, spermatocyte and spermatid) were studied by optical microscope. In the first day of blood collection, a significant increase in LH and FSH level was observed at concentrations of 10 and 30 mg/kg, respectively. Also, Testosterone and FSH level decreased significantly reduced at 10 mg/kg/bw concentration compared to control (P<0.05). In 15 days after of the last injection, level of testosterone (P<0.05) and LH (P<0. 05) significantly increased in concentrations of 10 and 30 mg/kg/bw respectively. Also, there was a significant reduction in level of FSH in the concentration of 10 mg/kg/bw (P<0.05). The examination of testis tissue sections showed a significant decrease (P<0.05) in density and number of cell types (spermatogonium, spermatocyte and spermatid) and anomalies in the spermatogenesis process, in a dose-dependent manner. The most disturbances was seen at a concentration of 30 mg/kg/bw of copper oxide nanoparticles. Copper oxide nanoparticles may interfere with the secretion of gonadotropins and testosterone and ultimately lead to a disruption of the spermatogenesis process.

Antioxidants can reduce the occurrence of long-term damages, caused by free radicals. Considering the importance of enhanced oxidative stress in the occurrence of nanoparticle-induced damages and effects of plant extracts on reducing oxidative stress, in this study, we aimed to evaluate the effects of copper oxide nanoparticles and hydroalcoholic extracts of Berberis vulgaris, Descurainia sophia, and silymarin on catalase, glutathione peroxidase, and malondialdehyde concentrations in male diabetic rats.
In this experimental study, 50 Wistar rats (250-350 g) were divided in ten groups (five rats per group): healthy controls, healthy rats receiving nanoparticles, healthy rats receiving Berberis vulgaris, Descurainia sophia, and silymarin extracts (independently), diabetic controls, diabetic rats receiving copper nanoparticles, and diabetic rats receiving the extracts independently. In diabetic groups, diabetes was induced in half of the rats, using alloxan at a dose of 120 mg/kg. In addition to copper oxide nanoparticles, the control and diabetic groups independently received 0.5 cc of Berberis vulgaris, Descurainia sophia, and Silybum marianum extracts via intraperitoneal injection for 30 days. Then, the animals were anesthetized with ketamine and the liver tissues were removed. The concentrations of catalase, glutathione peroxidase, and malondialdehyde were measured and compared.
FINDINGS: In diabetic groups treated with copper nanoparticles, a significant increase was reported in the concentration of malondialdehyde (from 4.7±0.447 to 5.05±0.405). Moreover, a significant decline was observed in the activity of catalase enzymes (from 36.8±1.48 to 36.2±1.4832) and glutathione peroxidase (from 75.4±3.9115 to 72.4±4.3362). Based on the findings, Silybum marianum was more effective than Berberis vulgaris and Descurainia sophia in diminishing the effects of cooper nanoparticles.
The present results showed that the studied herbal extracts could be used for moderating the effects of oxidative stress, induced by copper oxide nanoparticles

Maintain of fixed amount of glucose in blood has always been valuable. Especially in diabetic patients it is important to determine accurate amount of it. In this study we are trying to find a method to determination of the amount of serum glucose. First a biosensor was prepared using carbon paste electrode modified with Copper Oxide nanoparticles for determination of serum glucose. The synthesized Copper Oxide nanoparticles were studied by using a variety of chemical spectrum UV-Vis، XRD، SEM and TEM. XRD confirmed that our synthesized are Copper Oxide nanoparticles. By measuring of the oxidation currents in the several levels of glucose، the accuracy and efficiency of biosensor was studied. Based on a increase of the electrocatalytic response of the oxidized form of GOD to dissolved oxygen، the proposed biosensor exhibits a linear response to glucose concentrations ranging from 0 to 15 mM with a detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) of 9 µM at an applied potential of 0. 44 V which has better biosensing properties than those from other biosensors. This biosensor retained 89% of its initial response after 30 days storage at pH=7. Carbon paste electrode and Copper Oxide nanoparticles offer excellent catalytic activity toward hydrogen peroxide generation in enzymatic reaction between glucose oxidase and glucose، which would enable sensitive determination of glucose. This biosensor exhibited good stability، reproducibility and low interferences. It has been used to diagnose diabetes very fast and sensitively and to determine the glucose concentrations in serum samples with satisfactory results.