Ecofriendly Green Synthesis of Copper (II) Oxide Nanoparticles Using Corchorus olitorus Leaves (Molokhaia) Extract and Their Application for the Environmental Remediation of Direct Violet Dye via Advanced Oxidation Process

Antimicrobial activity of metal-based nanoparticles: a mini-review

The resistance of pathogenic microorganisms to antibiotics is one of the main problems of world health. Of particular concern are multidrug-resistant (MDR) bacteria. Infections caused by these microorganisms affect the appearance of acute or chronic diseases. In this regard, modern technologies, such as nanomaterials (NMs), especially promising nanoparticles (NPs), can possess antimicrobial properties or improve the effectiveness and delivery of known antibiotics. Their diversity and characteristics, combined with surface functionalization, enable multivalent interactions with microbial biomolecules. This article presents an overview of the most current research on replacing antibiotics with NPs, including the prospects and risks involved.

Green synthesis of MnO2-embedded Rauvolfia tetraphylla leaves (MnO2@RTL) for crystal violet dye removal and as an antibacterial agent

The application of green synthesized nanocomposites for the prevention of environmental pollution is increasing nowadays. Here, a green composite has been synthesized by embedding MnO2 on Rauvolfia tetraphylla leaves using its leaf extract hereinafter termed as MnO2@RTL, and demonstrated for crystal violet (CV) dye removal from simulated and real wastewater. The surface properties of the material were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), and Brunauer-Emmet-Teller (BET) surface area, pHZPC, and zeta potential. The material exhibits a remarkable adsorption capacity of 61.162 mg/g at 328 K and pH 7. The adsorption was best fitted with Pseudo-second-order kinetic (R2 = 0.998) and a combination of Langmuir and Freundlich isotherm model (R2 = 0.994-0.999). The thermodynamic study revealed spontaneous (ΔG values =  - 2.988 to - 4.978 kJ/mol) and endothermic (ΔH values = 6.830 to 11.018 kJ/mol) adsorption. After adsorption, 80% regeneration occurred with 50% methanol, and recycled up to five times. Advantageously, the material was able to remove CV dye in the presence of coexistent ions and from industrial wastewater, confirming field applicability. The adsorption capacity of the material is superior to previously reported materials. The standard deviation and relative standard deviations have been evaluated to be 0.000422-0.000667 and 0.473-0.749%, which suggests the reliability of the experiments. The exhausted material, after recycling, was pyrolyzed to overcome the disposal problem. It was established as a secondary adsorbent with 73% efficiency which makes the material win-win. The material showed antibacterial properties with Staphylococcus aureus bacteria with a zone of inhibition 5 mm.

Cytotoxicity, Antimicrobial, Anti-inflammatory and Antioxidant Activity of Camellia Sinensis and Citrus Mediated Copper Oxide Nanoparticle-An In vitro Study

Aim

Several applications of copper oxide nanoparticles (CuONPs) have been documented in various fields, including healthcare, dentistry, medication delivery, tissue and cancer imaging, biolabeling, and biosensing. Therefore, this study aimed to synthesize CuONPs using the plant extracts of Camellia Sinesis (CS) and citrus limon (CL). The nanoparticles were then evaluated for their cytotoxicity, antibacterial, anti-inflammatory, and antioxidant activities.

Materials and Methods

CuONPs were prepared using CS and CL through the green synthesis method. The Zone of Inhibition (ZOI) test was used to assess the antibacterial activity against strains of Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, and Candida albicans. The albumin denaturation assay was used to assess the substances' anti-inflammatory activity. The cytotoxicity was determined by conducting the brine shrimp lethality test. Additionally, the antioxidant nature was tested using the 1,1-diphenyl-2-picryl hydrazyl method.

Results

CuONPs mediated by CS and CL were successfully synthesized. The nanoparticles demonstrated significant antimicrobial activity against the bacteria being studied, specifically S. aureus. The cytotoxic effect was observed to be the least when the concentrations were below 20 µL. A potent antioxidant effect, characterized by its maximum absorbance at 517 nm, was observed at a concentration of 50 µL. A significant anti-inflammatory effect was noted for all tested concentrations.

Conclusion

The use of CS- and CL-mediated CuONPs demonstrates a favorable antimicrobial effect with reduced cytotoxicity, as well as improved anti-inflammatory and antioxidant effects at higher concentrations.

Efficacy of copper oxide nanoparticles using Piper longum and Piper betle

It is of interest to evaluate the antibacterial, anti-inflammatory, and antioxidant effects of copper nanoparticles synthesized using Piper longum and Piper betle. The copper nanoparticles were characterized using various techniques and found to have a diameter between 30 and 90 nm. The nanoparticles exhibited significant antibacterial activity against E. faecalis, S. aureus, C. albicans, and S. Mutans, comparable to gold standards. They also demonstrated anti-inflammatory effects similar to the gold standard values. Furthermore, the copper nanoparticles displayed antioxidant capabilities, with maximum inhibition of 85.16% at 50 g/ml and a minimum inhibition of 50.62% at 10 g/ml. Overall, the study suggests that Piper longum and Piper betle mediated copper nanoparticles possess promising antibacterial, anti-inflammatory, and antioxidant properties, indicating their potential use in various applications.