Role of Green-Synthesized Silver and Copper Oxide Nanoparticles in Modulating DNA Topoisomerase III Activity and DNA Methyltransferase I Protein Expression Through In Vitro and In Silico Approaches

Synthesis of silver and copper oxide nanoparticles using Myristica fragrans fruit extract: Antimicrobial and catalytic applications

Continuous flow experiments (450 mL min−1) were performed in household filter in order to investigate the removal and/or inactivation of T4 bacteriophage, using granular activated carbon (GAC) modified with silver and/or copper oxide nanoparticles at different concentrations. GAC and modified GAC were characterized by X-ray diffractometry, specific surface area, pore size and volume, pore average diameter, scanning electron microscopy, transmission electron microscopy, zeta potential and atomic absorption spectroscopy. The antiviral activity of the produced porous media was evaluated by passing suspensions of T4 bacteriophage (∼105 UFP/mL) through filters. The filtered water was analyzed for the presence of the bacteriophage and the release of silver and copper oxide. The porous media containing silver and copper oxide nanoparticles showed high inactivation capacity, even reaching reductions higher than 3 log. GAC6 (GAC/Ag0.5%Cu1.0%) was effective in the bacteriophage inactivation, reaching 5.53 log reduction. The levels of silver and copper released in filtered water were below the recommended limits (100 ppb for silver and 1000 ppb for copper) in drinking water. From this study, it is possible to conclude that activated carbon modified with silver and copper oxide nanoparticles can be used as a filter for virus removal in the treatment of drinking water.

Chapter Eight - Metallic silver and copper oxide nanoparticles: Uses in food preservation and impacts on the environment

ABSTRACT: The copper-doped silver and nickel oxide nanoparticles were prepared by the co-precipitation method in which the silver oxide (Ag2O) and nickel oxide (NiO) nanoparticles are doped with copper in 4:1 in the presence of sodium dodecyl sulfate (SDS), a surfactant. Then various analytical studies were carried out by using X-ray diffraction (XRD) and Diffuse reflectance spectroscopy (DRS). The XRD analysis revealed the crystalline structure and the size of nanoparticles was determined by using Scherrer’s formula. The XRD data showed the effect of doping on crystallinity and size. It was found that the size of nanoparticles was reduced without any change in crystallinity after doping. DRS results showed that when silver oxide and nickel oxide nanoparticles were doped with copper oxide nanoparticles, the energy band gap was shifted to a lesser value, i.e., from 1.50 to 1.17 eV for Ag2O and from 2.29 to 2.08 eV for NiO, respectively. The photocatalytic degradation of methylene blue (MB) and eriochrome black-T (EBT) by nanoparticles was monitored by UV-Vis spectroscopy. The antimicrobial activity of the synthesized nanoparticles was checked by using well diffusion assay and it was found that doped nanoparticles were more active than the undoped ones.

Campylobacter jejuni is a major cause of global foodborne illnesses. To develop alternative antimicrobial strategies against C. jejuni, this study designed and optimized the green synthesis of metallic nanoparticles (NPs) with intracellular components of the medicinal fungus Ganoderma sessile to provide the needed reducing and stabilizing agents. NPs were characterized by transmission electron microscopy and dynamic light scattering, and the quasi-spherical NPs had sizes of 2.9 ± 0.9 nm for the copper oxide NPs and 14.7 ± 0.6 nm for the silver NPs. Surface charge assessment revealed zeta potentials of -21.0 ± 6.5 mV and -24.4 ± 7.9 mV for the copper oxide and silver NPs, respectively. The growth inhibition of C. jejuni by the NPs occurred through attachment to the outer cell membrane and subsequent intracellular internalization and resulted in minimum inhibitory concentrations of the silver NPs at 6 µg/mL and copper oxide NPs at 10 µg/mL. On the other hand, a differential ROS production caused by silver and copper NPs was observed. In summary, this research presents the first demonstration of using green synthesis with the medicinal fungus G. sessile to produce metallic NPs that effectively inhibit C. jejuni growth, providing a sustainable and effective approach to the traditional use of antimicrobials.

Synthesis and antibacterial activity of graphene oxide decorated by silver and copper oxide nanoparticles

Unanticipated increase in the use of silver (Ag) and copper oxide (CuO) nanoparticles (NPs) due to their antimicrobial properties is eliciting environmental health concern because of their coexistence in the aquatic environment. Therefore, we investigated the genetic and systemic toxicity of the individual NPs and their mixture (1:1) using the piscine micronucleus (MN) assay, haematological, histopathological (skin, gills and liver) and hepatic oxidative stress analyses [malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT)] in the African mud catfish, Clarias gariepinus. The fish were exposed to sublethal concentrations (6.25-100.00mg/L) of each NP and their mixture for 28days. Both NPs and their mixture induced significant (p < 0.05) increase in MN frequency and other nuclear abnormalities. There was significant decrease in haemoglobin concentration, red and white blood cell counts. Histopathological lesions observed include epidermal skin cells and gill lamellae hyperplasia and necrosis of hepatocytes. The levels of MDA, GSH and activities of SOD and CAT were impacted in C. gariepinus liver following the exposure to the NPs and their mixture. Interaction factor analysis of data indicates antagonistic genotoxicity and oxidative damage of the NPs mixture. These results suggest cytogenotoxic effects of Ag NPs, CuO NPs and their mixture via oxidative stress in Clarias gariepinus.

Interactions between suspension characteristics and physicochemical properties of silver and copper oxide nanoparticles: A case study for optimizing nanoparticle stock suspensions using a central composite design

Nanotechnology has grown significantly and keeps advancing quickly, with more applications aimed at improving human health and meeting different needs. Overexpression of certain receptors is seen in most cases of cancer. Targeting these receptors with nanoparticles provides a promising way to treat patients with resistant cancers. This study aimed to synthesize copper oxide (CuO NPs) and silver nanoparticles (Ag NPs) using leaf, stem, and root extracts of Ocimum tenuiflorum , with ethanol as the solvent. The researchers characterized the nanoparticles using ultraviolet–visible (UV–Vis) and Fourier transform infrared (FT‐IR) spectroscopy. The phytochemicals in the extracts were analyzed to identify secondary metabolites. A molecular docking study was conducted to assess the binding interactions between the phytochemicals in the nanoparticles and three potential cancer targets: estrogen, gonadotropin‐releasing hormone, and somatostatin receptors. The results confirmed the successful synthesis of CuO and Ag NPs from different parts of Ocimum tenuiflorum . Ag NPs showed a characteristic UV–Vis peak at 419–422 nm, while CuO NPs had a peak at 262 nm. FT‐IR analysis showed that functional groups from secondary metabolites like polyphenols and terpenoids were involved in nanoparticle synthesis and capping. Molecular docking revealed strong binding interactions of cirsimaritin with somatostatin (binding energy: −96.8 kJ/mol) and of rosmarinic acid with the same receptor (−88.4 kJ/mol). Overall, the study concludes that cirsimaritin and rosmarinic acid in Ag and CuO NPs effectively target somatostatin and other receptors. This requires further in vitro studies to explore their therapeutic potential against various cancer cell lines.

Background: Nanotechnology is the greatest promising technique for generating new applications in water purification.Green synthesis of silver nanoparticles and copper oxide nanoparticles is an ecofriendly, cheap and non-toxic more than chemical and physical methods.Aim: This study focuses on green synthesis, characterization, antibacterial activities of silver nanoparticles and copper oxide nanoparticles synthesized using Moringa oleifera leaf and stem extract and its application in water purification.Materials and Methods: The green synthesis of silver nanoparticles was done by using Moringa oleifera leaf and stem extract and 1mM of silver nitrate solution while copper oxide nanoparticles were synthesized by using Moringa oleifera leaf and stem extract and 10mM of copper sulfate pentahydrate solution.pH, temperature and the mixture reaction time are parameters affecting the formation of silver nanoparticles and copper oxide nanoparticles.Results: In this study, various techniques and devices used to characterize and confirms the formation of silver nanoparticles and copper oxide nanoparticles included visual observation, UV-Vis spectroscopy, TEM, FTIR, and EDX.Silver nanoparticles and copper oxide nanoparticles showed antimicrobial activity against E. coli ATCC 8739 and S. typhi ATCC 14028 and isolated microorganisms from tested water sample which included Pseudomonas aeruginosa and Klebsiella variicola.Cellulose filter paper which coated with silver nanoparticles and copper oxide nanoparticles showed good effect in water purification as its good antimicrobial activity against microorganisms, increasing pH value and reducing conductivity, total alkalinity values and Pb concentration value.Conclusion: The results from this study indicate that bionanoparticles from moringa have an antimicrobial activity that can be applied in water Purification.

Prevention of bacterial growth among root canal treatment sessions is a prerequisite for successful root canal treatment. The most common way to achieve this is to use calcium hydroxide in the treatment sessions. Some studies have shown calcium hydroxide inefficiency in this field. The aim of this study was to investigate and compare the effects of silver, copper, zinc oxide and magnesium oxide nanoparticles on the inhibitory effects of calcium hydroxide based on Enterococcus faecalis species. Enterococcus faecalis bacteria having 0.5 McFarland concentration were prepared. Plates containing BHI agar medium were prepared. In each plate, four wells were created and the plate was cultured using a sterile swab. Afterwards, calcium hydroxide composition of 1% and 2% concentration from silver, copper, zinc oxide and magnesium oxide nanoparticles were prepared separately, as well as the combination of calcium hydroxide with 1% silver in combination with 1% of copper, zinc oxide and magnesium oxide nanoparticles, which were then transferred to the wells. After 24 hours of incubation, the inhibition zone diameter was measured. Data were analyzed by Mann-Withney test. At 1% concentration, only the combination of copper nanoparticles with calcium hydroxide could significantly create an inhibition zone larger than calcium hydroxide alone (P value <0.5). At 2% concentration, the combination of copper nanoparticles with calcium hydroxide, and the combination of silver nanoparticles with calcium hydroxide, were significantly higher than calcium hydroxide alone (P value <0.5). The calcium hydroxide composition containing 1% silver nanoparticles in combination with 1% copper, zinc oxide and magnesium oxide nanoparticles significantly increased the growth inhibition zone more than calcium hydroxide alone. (P Value <0.5). Copper nanoparticles showed the best antibacterial properties among silver, copper, magnesium oxide and zinc oxide nanoparticles in combination with calcium hydroxide. Also, the combination of 1% of nanoparticles with each other increases antibacterial properties.

Objective: Heat cure acrylic is the most common used material for fabrication of dental prosthesis. This in vitro study was undertaken to discover the effect of nanoparticles on antibacterial properties of the denture base. Methods: Nanosized Silver and Copper oxide were impregnated at 1%, 3% and 5% by weight to the monomer of methyl methacrylate with the aid of probe sonicator before mixing it with acrylic powder. Seventy samples were prepared to determine the effect of the nanoparticles on Streptococcus mutans and Escherichia coli. Results: The results for Streptococcus mutans revealed a statistically significant difference (p&lt;0.05) for both nanoparticles at the three concentrations except for 1% silver. The most influential concentration on the tested material was 3% copper oxide, which caused a 49% decline. Regarding Escherichia coli, only 3% and 5% of silver showed a statistically significant difference. Conclusions: Within the limitations of this in vitro study, it can be concluded that the addition of Silver nanoparticles into heat-cure acrylic was more effective against Streptococcus mutans than Escherichia coli. Regarding Copper oxide nanoparticles, it caused a drastic reduction in Streptococcus mutans activity but with no significant effect on Escherichia coli for all of its concentrations. Since denture stomatitis is caused by both bacterial species, Silver nanoparticles might be considered as a suitable additive for reducing denture induced infections.

Conventional wound dressings often lack efficient antimicrobial properties and may exhibit limited bio‐compatibility, necessitating the development of advanced solutions for effective wound healing. Green synthesis of nanoparticles opens the door to a strategy that is efficient in terms of pharmaceutical biotechnology, besides being nontoxic and eco‐friendly. In the present study, Centella asiatica leaf extract conjugated with silver nanoparticles and copper oxide nanoparticles are synthesized and their bioactivity is compared. Gas chromatography mass spectrometry (GC‐MS) results show 4‐butoxy‐1‐Butanol, Phthalic acid, and 2‐propyldecan‐1‐ol as major phytochemicals in Centella asiatica. The green‐synthesized silver nanoparticles (Ag‐NPs) and copper oxide nanoparticles (CuO‐NPs) are characterized using transmission electron microscopy (TEM), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). TEM results confirm the circular morphology for Ag‐NPs and elliptical structures for CuO‐NPs, whereas energy dispersive x‐ray (EDX) spectrum confirms the presence of Cu and Ag in their respective samples. XRD spectrum confirms that both the nanoparticles exhibit high crystallinity. Both nanoparticles demonstrate satisfactory radical scavenging activity as confirmed by the 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) assay. CuO‐NPs exhibit greater antibacterial activity against Escherichia coli (E. coli) and Methicillin‐resistant Staphylococcus aureus (MRSA) in comparison to the Ag‐NPs evident from the clear zone of inhibition obtained. In conclusion, green synthesized CuO‐NPs prove to have enhanced wound healing activity in the NIH3T3 fibroblast cells than Ag‐NPs.

The Influence of Microbacterium hominis and Bacillus licheniformis Extracellular Polymers on Silver and Iron Oxide Nanoparticles Production; Green Biosynthesis and Mechanism of Bacterial Nano Production Due to the abundant applications of metal nanoparticles on different area, researchers are always looking for fast, easy, cheap and non-toxic way to synthesis nanoparticles. In scientific communities, green and biological synthesis of nanoparticles have got more attention, so in this study 300 μl of extracellular polysaccharides (28.8717 mg/L and 35.5344 mg/L) from Microbacterium hominis and Bacillus licheniformis respectively were used to produce silver, silver oxide, iron oxide and iron metal nanoparticles from silver nitrate and iron chloride (1 mM).These strains were isolated on Caso Agar medium enriched with 20% sucrose. It was interesting that bacteria without polysaccharide could not produce these nanoparticles while the whole cells with extracellular polysaccharide do the same reaction as polysaccharides and carboxy methyl cellulose. FTIR analyzing showed these polysaccharides has similarities in structure with carboxy methyl cellulose and have certain functional groups such as hydroxyl, carbonyl, methyl and aldehyde, so the mechanism for making nanoparticles by these microorganisms is probably is not related to enzyme activities. The properties of nanoparticles were investigated by XRD, AFM and UV absorption (200-800 nm). The crystalline, approximate size and color changes were detected. Iron and iron oxide nanoparticles, was cubic structures with sizes of 29-42 nm and silver and silver oxide nanoparticles was hexagonal with 12-42 nm.

The purpose of this study was to evaluate the amount of released of silver and copper oxide nanoparticles when they were incorporated in heat cured acrylic resin denture, chemical cured soft liner, and cream type adhesive.Material and methods: A total number of 240 samples were prepared, 80 denture base samples, 80 liner, and 80 adhesives, and 10 samples from each material were free from nanoparticles that act as a control. The remaining samples were divided into two groups: (Group I) contained denture base, liner and adhesive samples modified with copper-oxide nanoparticles concentration by (0.1%, 0.3%, and 0.5%, 10 sample each), and (Group II) has the same number of samples but modified with same silver nanoparticles concentrations. The samples were placed in distilled water for one week and the amount of release was measured by spectrophotometer. The recordings data were analyzed using Two-way repeated measures Analysis of Variance (ANOVA) to compare between the three groups as well as to study the effect of time within each group. Bonferroni’s post-hoc test was used for pair-wise comparisons. P< 0.05 was considered.Results: Release was higher in denture adhesive followed by denture liner and denture base respectively in the two groups. The amount of release increased with increasing nanoparticles concentration in denture base and adhesive but not in denture liner. There was no significant difference between Group I, and Group II.Conclusion: Nanoparticle release was affected by the type of prosthetic material, nanoparticle concentration, but not nanoparticles type.