Hindering the biofilm of microbial pathogens and cancer cell lines development using silver nanoparticles synthesized by epidermal mucus proteins from Clarias gariepinus.

Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV-vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200-6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.

Unveiling biological activities of biosynthesized starch/silver-selenium nanocomposite using Cladosporium cladosporioides CBS 174.62.

BACKGROUND AND OBJECTIVES: Microbial cells capability to tolerate the effect of various antimicrobial classes represent a major worldwide health concern. The flexible and multi-components nanocomposites have enhanced physicochemical characters with several improved properties. Thus, different biological activities of biosynthesized starch/silver-selenium nanocomposite (St/Ag-Se NC) were assessed. METHODOLOGY: The St/Ag-Se NC was biosynthesized using Cladosporium cladosporioides CBS 174.62 (C. cladosporioides) strain. The shape and average particle size were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM), respectively. On the other hand, the St/Ag-Se NC effect on two cancer cell lines and red blood cells (RBCs) was evaluated and its hydrogen peroxide (H2O2) scavenging effect was assessed. Moreover, its effects on various microbial species in both planktonic and biofilm growth forms were examined. RESULTS: The St/Ag-Se NC was successfully biosynthesized with oval and spherical shape and a mean particle diameter of 67.87 nm as confirmed by the HR-TEM analysis. St/Ag-Se NC showed promising anticancer activity toward human colorectal carcinoma (HCT-116) and human breast cancer (MCF-7) cell lines where IC50 were 21.37 and 19.98 µg/ml, respectively. Similarly, little effect on RBCs was observed with low nanocomposite concentration. As well, the highest nanocomposite H2O2 scavenging activity (42.84%) was recorded at a concentration of 2 mg/ml. Additionally, Staphylococcus epidermidis (S. epidermidis) ATCC 12,228 and Candida albicans (C. albicans) ATCC 10,231 were the highly affected bacterial and fungal strains with minimum inhibitory concentrations (MICs) of 18.75 and 50 µg/ml, respectively. Moreover, the noticeable effect of St/Ag-Se NC on microbial biofilm was concentration dependent. A high biofilm suppression percentage, 87.5% and 68.05%, were recorded with S. epidermidis and Staphylococcus aureus (S. aureus) when exposed to 1 mg/ml and 0.5 mg/ml, respectively. CONCLUSION: The biosynthesized St/Ag-Se NC showed excellent antioxidant activity, haemocompatibility, and anti-proliferative effect at low concentrations. Also, it exhibited promising antimicrobial and antibiofilm activities.

A mini review on green nanotechnology and its development in biological effects.

The utilization of living organisms for the creation of inorganic nanoscale particles is a potential new development in the realm of biotechnology. An essential milestone in the realm of nanotechnology is the process of creating dependable and environmentally acceptable metallic nanoparticles. Due to its increasing popularity and ease, use of ambient biological resources is quickly becoming more significant in this field of study. The phrase "green nanotechnology" has gained a lot of attention and refers to a variety of procedures that eliminate or do away with hazardous compounds to repair the environment. Green nanomaterials can be used in a variety of biotechnological sectors such as medicine and biology, as well as in the food and textile industries, wastewater treatment and agriculture field. The construction of an updated level of knowledge with utilization and a study of the ambient biological systems that might support and revolutionize the creation of nanoparticles (NPs) are presented in this article.

Potential of biosynthesized zinc oxide nanoparticles to control Fusarium wilt disease in eggplant (Solanum melongena) and promote plant growth.

In this study, a novel, non-toxic, eco-friendly zinc oxide nanoparticles (ZnO-NPs) was used instead of the synthetic fungicides widely used to control the destructive phytopathogenic fungus Fusarium oxysporum, the causative agent of wilt disease in Solanum melongena L. Herein, the biosynthesized ZnO-NPs was carried out by Penicillium expansum ATCC 7861. In vitro, mycosynthesized ZnO-NPs exhibited antifungal activity against Fusarium oxysporum. In vivo, ZnO-NPs suppressed Fusarium wilt disease in cultivated Solanum melongena L. by decreasing the disease severity with 75% of plant protection. Moreover, ZnO-NPs stimulated the recovery of eggplant as an indicated by improving of morphological and metabolic indicators including plant height(152.5%), root length(106.6%), plant fresh biomass (146%), chlorophyll a (102.8%), chlorophyll b (67.86%), total soluble carbohydrates (48.5%), total soluble protein (81.8%), phenol (10.5%), antioxidant activity and isozymes compared with infected control. Therefore, this study suggests using mycosynthesized ZnO-NPs as an alternative to synthetic fungicides not only to eradicate the Fusarium wilt disease in cultivated eggplant (Solanum melongena) but also to promote the growth parameters and metabolic aspects.

Endophytic actinomycetes Streptomyces spp mediated biosynthesis of copper oxide nanoparticles as a promising tool for biotechnological applications.

In this study, two endophytic actinomycetes isolates Oc-5 and Acv-11, were isolated from healthy leaves of medicinal plant Oxalis corniculata L. These isolates were identified as Streptomyces zaomyceticus Oc-5 and Streptomyces pseudogriseolus Acv-11 using 16S rRNA gene sequence. Biomass extract of these strains were used as a greener attempt for synthesis of copper oxide nanoparticles (CuO-NPs). The synthesized NPs were characterized by UV-Vis spectroscopy, Fourier transform infra-red (FT-IR) spectroscopy, X-ray diffraction (XRD)' transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS). Green synthesized NPs showed surface plasmon resonance (SPR) absorption band at 400 nm, crystalline nature, spherical-shaped with an average size of 78 nm and 80.0 nm for CuO-NPs synthesized using strain Oc-5 and Acv-11, respectively. The bioactivities of CuO-NPs were evaluated. Results revealed that CuO-NPs exhibited promising antimicrobial activity against prokaryotic and eukaryotic microbial cells (Gram positive bacteria, Gram negative bacteria, unicellular and multicellular fungi). In addition, it showed antimicrobial potential against phyto-pathogenic fungal strains Fusarium oxysporum, Pythium ultimum, Aspergillus niger and Alternaria alternata. We further explored the in vitro antioxidant activity and cytotoxicity for biosynthesized CuO-NPs. The results revealed that' scavenging and total antioxidant activity for NPs synthesized using Streptomyces pseudogriseolus Acv-11 was better than those synthesized by Streptomyces zaomyceticus Oc-5. Also, the morphological changes and cell viability for Vero and Caco-2 cell line due to NPs treatments were assessed using MTT assay method. Furthermore, Larvicidal efficacy against Musca domestica and Culex pipiens was evaluated. The results obtained in this study clearly showed that biosynthesized CuO-NPs exhibited effective bioactivity and, therefore, provide a base for the development of versatile biotechnological applications soon.

In-Vitro cytotoxicity, antibacterial, and UV protection properties of the biosynthesized Zinc oxide nanoparticles for medical textile applications.

Nowadays, medical textiles have become the most essential and developing part in human healthcare sector. This work was undertaken with a view to harness the bio-active macromolecules secreted by fungi e.g. proteins and enzymes in bio-synthesis of ZnO nanoparticles for multifunctional textiles such as antibacterial activity and UV protection with considering the cytotoxicity limitation. Herein, the isolated fungus, Aspergillus terreus, was allowed to produce proteins which has affinity to cape ZnO-NPs. Various factors affecting the behavior of the secreted proteins on the formed nanoparticles were investigated. Thorough characterizations of the protein capped ZnO-NPs were performed by the using of UV-Visible spectroscopy, transmission electron microscope (TEM) Fourier Transform-Infra Red (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis and Dynamic light scattering analysis (DLS). Prior treatment of cotton fabrics with ZnO-NPs, the cytotoxicity of the protein capped ZnO-NPs was examined. After that, the antibacterial activity of the ZnO-NPs before and after treating of cotton fabrics, besides, the UV-protection (UPF) properties were investigated. Results obviously demonstrated the ability of the bio-secreted protein to cape and reduce ZnO to spherical ZnO-NPs with particle size lied around 10-45 nm, as indicated form UV-vis., spectra TEM, Zeta sizer, FTIR and XRD. Regarding to the results of cytotoxicity, the treatment of the cotton fabrics with ZnO-NPs were performed at safe dose (20 ppm). At this dose, ZnO-NPs loaded samples exhibited reasonable antibacterial activity against both Gram positive and Gram negative bacteria; besides, good UV-protection with reasonable increase in UVA and UVB blocking values. Indeed, nanotechnology based microbiological active molecules opens up new opportunities for us to explore novel applications in terms of green technology.

Antibacterial Activity of Green Synthesized Silver Nanoparticles Using Lawsonia inermis Against Common Pathogens from Urinary Tract Infection.

New and creative methodologies for the fabrication of silver nanoparticles (Ag-NPs), which are exploited in a wide range of consumer items, are of significant interest. Hence, this research emphasizes the biological approach of Ag-NPs through Egyptian henna leaves (Lawsonia inermis Linn.) extracts and analysis of the prepared Ag-NPs. Plant extract components were identified by gas chromatography mass spectrometry (GC-mass). The analyses of prepared Ag-NPs were carried out through UV-visible (UV-Vis), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) analysis. UV-Vis reveals that Ag-NPs have a maximum peak at 460 nm in visible light. Structural characterization recorded peaks that corresponded to Bragg's diffractions for silver nano-crystal, with average crystallite sizes varying from 28 to 60 nm. Antibacterial activities of Ag-NPs were examined, and it is observed that all microorganisms are very sensitive to biologically synthesized Ag-NPs.

Expression of concern: Cefotaxime incorporated bimetallic silver-selenium nanoparticles: promising antimicrobial synergism, antibiofilm activity, and bacterial membrane leakage reaction mechanism.

Expression of concern for 'Cefotaxime incorporated bimetallic silver-selenium nanoparticles: promising antimicrobial synergism, antibiofilm activity, and bacterial membrane leakage reaction mechanism' by Abdelrahman A. Elakraa et al., RSC Adv., 2022, 12, 26603-26619, https://doi.org/10.1039/D2RA04717A.

Synthesis, Optimization, and Characterization of Cellulase Enzyme Obtained from Thermotolerant Bacillus subtilis F3: An Insight into Cotton Fabric Polishing Activity.

The efficacy of 40 bacterial isolates obtained from hot spring water samples to produce cellulase enzymes was investigated. As a result, the strain Bacillus subtilis F3, which was identified using traditional and molecular methods, was selected as the most potent for cellulase production. Optimization was carried out using one-factor-at-a-time (OFAT) and BOX-Behnken Design to detect the best conditions for the highest cellulase activity. This was accomplished after an incubation period of 24 h at 45°C and pH 8, with an inoculum size of 1% (v/v), 5 g/l of peptone as nitrogen source, and 7.5 g/l of CMC. Moreover, the best concentration of ammonium sulfate for cellulase enzyme precipitation was 60% followed by purification using a dialysis bag and Sephadex G-100 column chromatography to collect the purified enzyme. The purified cellulase enzyme was characterized by 5.39-fold enrichment, with a specific activity of 54.20 U/mg and a molecular weight of 439 kDa. There were 15 amino acids involved in the purified cellulase, with high concentrations of 160 and 100 mg/l for glycine and proline respectively. The highest stability and activity of the purified cellulase was attained at pH 7 and 50°C in the presence of 150 ppm of CaCl2, NaCl, and ZnO metal ions. Finally, the biopolishing activity of the cellulase enzyme, as indicated by weight loss percentages of the cotton fabric, was dependent on concentration and treatment time. Overall, the thermotolerant B. subtilis F3 strain has the potential to provide highly stable and highly active cellulase enzyme for use in biopolishing of cotton fabrics.

Mitigation of the hyperglycemic effect of streptozotocin-induced diabetes albino rats using biosynthesized copper oxide nanoparticles.

Diabetes mellitus is a metabolic disorder described by compromised insulin synthesis or resistance to insulin inside the human body. Diabetes is a persistent metabolic condition defined by elevated amounts of glucose in the bloodstream, resulting in a range of potential consequences. The main purpose of this study was to find out how biosynthesized copper oxide nanoparticles (CuONPs) affect the blood sugar levels of diabetic albino rats induced by streptozotocin (STZ). In the current study, CuONPs were successfully biosynthesized using Saccharomyes cervisiae using an eco-friendly method. Characterization results revealed that biosynthesized CuONPs appeared at 376 nm with a spherical shape with sizes ranging from 4 to 47.8 nm. Furthermore, results illustrated that administration of 0.5 and 5 mg/kg CuONP in diabetic rats showed a significant decrease in blood glucose levels accompanied by elevated insulin levels when compared to the diabetic control group; however, administration of 0.5 mg/kg is the best choice for diabetic management. Furthermore, it was found that the group treated with CuONPs exhibited a noteworthy elevation in the HDL-C level, along with a depletion in triglycerides, total cholesterol, LDL-C, and VLDL-cholesterol levels compared to the diabetic control group. This study found that administration of CuONPs reduced hyperglycemia and improved pancreatic function as well as dyslipidemia in diabetic rats exposed to STZ, suggesting their potential as a promising therapeutic agent for diabetes treatment.

Recent Insights into Nanotechnology in Colorectal Cancer.

Colorectal cancer (CRC) is the third cancer among the known causes of cancer that impact people. Although CRC drug options are imperfect, primary detection of CRC can play a key role in treating the disease and reducing mortality. Cancer tissues show many molecular markers that can be used as a new way to advance therapeutic methods. Nanotechnology includes a wide range of nanomaterials with high diagnostic and therapeutic power. Several nanomaterials and nanoformulations can be used to treat cancer, especially CRC. In this review, we discuss recent insights into nanotechnology in colorectal cancer.

Influence of biosynthesized magnesium oxide nanoparticles on growth and physiological aspects of cowpea (Vigna unguiculata L.) plant, cowpea beetle, and cytotoxicity.

Recently, agricultural management innovation has incorporated engineered nanoparticles. The current investigation was carried out to produce magnesium oxide nanoparticles (MgONPs) for the first time applying S. cerevisiae extract. FTIR, XRD, HRTEM, and zeta potential analysis were used to characterize the MgONPs. The FTIR data show that the bioactive substances reduce and cap the synthesized MgONPs. The crystalline metallic MgONPs had four significant peaks in the XRD pattern. The size and form of MgONPs were validated by TEM, which exhibited spherical structures with an average size of 27 nm. The effect of various dosages of MgONPs administered to the cowpea (Vigna unguiculata L.) plant on all in vitro parameters was shown to be significant in the study. The concentration 200 ppm was the most significant treatment which increased shoot length, shoot dry-weight and root dry-weight by 27.35%, 45.09%, and 31.91% when compared with the untreated cowpea plants. MgONPs significantly increased photosynthetic pigments, with 150 ppm treatment significantly increasing soluble proteins and carbohydrates. MgONPs effectively treated cowpea C. maculatus, with dose and time-dependent insecticidal activity. MgONPs death rates varied by 82.66% and 100% on fifth day. Biochemical and histopathological studies of rats were investigated. Rats treated with MgONPs showed higher GOT, GPT, Urea levels, but lower creatinine, indicating significant differences. MgONPs-treated rats' liver showed mild to moderate histopathologic changes, including portal blood vessel congestion, lymphocytic cholangitis, and degenerative changes. MgONPs has the potential to improve cowpea development outcomes and suppress grain insects (C. maculatus).

Biosynthesis of Silver and Gold Nanoparticles and Their Efficacy Towards Antibacterial, Antibiofilm, Cytotoxicity, and Antioxidant Activities.

The World Health Organization (WHO) reports that the emergence of multidrug-resistant and the slow advent of novel and more potent antitumor and antimicrobial chemotherapeutics continue to be of the highest concern for human health. Additionally, the stability, low solubility, and negative effects of existing drugs make them ineffective. Studies into alternative tactics to tackle such tenacious diseases was sparked by anticancer and antibacterial. Silver (Ag) and gold (Au) nanoparticles (NPs) were created from Trichoderma saturnisporum, the much more productive fungal strain. Functional fungal extracellular enzymes and proteins carried out the activities of synthesis and capping of the generated nano-metals. Characterization was done on the obtained Ag-NPs and Au-NPs through UV-vis, FTIR, XRD, TEM, and SEM. Additionally, versus methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Klebsiella pneumoniae, the antibacterial activities of Ag-NPs and Au-NPs were assessed. In particular, the Ag-NPs were more effective against pathogenic bacteria than Au-NPs. Furthermore, antibiofilm study that shown Au-NPs had activity more than Ag-NPs. Interestingly, applying the DPPH procedure, these noble metallic NPs had antioxidant activity, in which the IC50 for Ag-NPs and Au-NPs was 73.5 µg/mL and 190.0 µg/mL, respectively. According to the cytotoxicity evaluation results, the alteration in the cells was shown as loss of their typical shape, partial or complete loss of monolayer, granulation, shrinking, or cell rounding with IC50 for normal Vero cell were 693.68 µg/mL and 661.24 µg/mL, for Ag-NPs and Au-NPs, respectively. While IC50 for cancer cell (Mcf7) was 370.56 µg/mL and 394.79 µg/mL for Ag-NPs and Au-NPs, respectively. Ag-NPs and Au-NPs produced via green synthesis have the potential to be employed in the medical industry as beneficial nanocompounds.

Characterizations of highly efficient moderately halophilic toluene degrading exiguobacterium mexicanum M7 strain isolated from Egyptian saline sediments.

Toluene and other monoaromatic compounds are released into the environment particularly saline habitats due to the inappropriate disposal methods of petroleum products. Studying the bio-removal strategy is required to clean up these hazardous hydrocarbons that threaten all ecosystem life using halophilic bacteria with higher biodegradation efficiency of monoaromatic compounds as a sole carbon and energy source. Therefore, sixteen pure halophilic bacterial isolates were obtained from saline soil of Wadi An Natrun, Egypt, which have the ability to degrade toluene and consume it as the only source of carbon and energy. Amongst these isolates, isolate M7 exhibited the best growth with considerable properties. This isolate was selected as the most potent strain and identified based on phenotypic and genotypic characterizations. The strain M7 was belonging to Exiguobacterium genus and founded to be closely matched to the Exiguobacterium mexicanum with a similarity of 99%. Using toluene as sole carbon source, strain M7 showed good growth at a wide range temperature degree (20-40ºC), pH (5-9), and salt concentrations (2.5-10%, w/v) with optimal growth conditions at 35ºC, pH 8, and 5%, respectively. The biodegradation ratio of toluene was estimated at above optimal conditions and analyzed using Purge-Trap GC-MS. The results showed that strain M7 has the potentiality to degraded 88.32% of toluene within greatly short time (48 h). The current study findings support the potential ability to use strain M7 as a biotechnological tool in many applications such as effluent treatment and toluene waste management.

Potential Antimicrobial and Antibiofilm Properties of Copper Oxide Nanoparticles: Time-Kill Kinetic Essay and Ultrastructure of Pathogenic Bacterial Cells.

Mycosynthesis of nanoparticle (NP) production is a potential ecofriendly technology for large scale production. In the present study, copper oxide nanoparticles (CuONPs) have been synthesized from the live cell filtrate of the fungus Penicillium chrysogenum. The created CuONPs were characterized via several techniques, namely Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the biosynthesized CuONPs were performed against biofilm forming Klebsiella oxytoca ATCC 51,983, Escherichia coli ATCC 35,218, Staphylococcus aureus ATCC 25,923, and Bacillus cereus ATCC 11,778. The anti-bacterial activity result was shown with the zone of inhibition determined to be 14 ± 0.31 mm, 16 ± 0.53 mm, 11 ± 0.57 mm, and 10 ± 0.57 mm respectively. Klebsiella oxytoca and Escherichia coli were more susceptible to CuONPs with minimal inhibitory concentration (MIC) values 6.25 and 3.12 µg/mL, respectively, while for Staphylococcus aureus and Bacillus cereus, MIC value was 12.5 and 25 µg/mL, respectively. The minimum biofilm inhibition concentration (MBIC) result was more evident, that the CuONPs have excellent anti-biofilm activity at sub-MIC levels reducing biofilm formation by 49% and 59% against Klebsiella oxytoca and Escherichia coli, while the results indicated that the MBIC of CuONPs on Bacillus cereus and Staphylococcus aureus was higher than 200 µg/mL and 256 µg/mL, respectively, suggesting that these CuONPs could not inhibit mature formatted biofilm of Bacillus cereus and Staphylococcus aureus in vitro. Overall, all the results were clearly confirmed that the CuONPs have excellent anti-biofilm ability against Klebsiella oxytoca and Escherichia coli. The prepared CuONPs offer a smart approach for biomedical therapy of resistant microorganisms because of its promoted antimicrobial action, but only for specified purposes.

Preparation of new surface coating based on modified oil-based polymers blended with ZnO and CuZnO NPs for steel protection.

In our paper, we have synthesized modified PEA and alkyd resin by replacing the new source of polyol (SDEA) which was confirmed by different analyses such as IR, and 1HNMR spectra. A series of conformal, novel, low-cost, and eco-friendly hyperbranched modified alkyd and PEA resins were fabricated with bio ZnO, CuO/ZnO) NPs through an ex-situ method for mechanical and anticorrosive coatings. The synthesized biometal oxides NPs and its composite modified alkyd and PEA were confirmed by FTIR, SEM with EDEX, TEM, and TGA, and can be stably dispersed into modified alkyd and PEA resins at a low weight fraction of 1%. The nanocomposite coating was also subjected to various tests to determine their surface adhesion, which ranged from (4B-5B), physico-mechanical characteristics such as scratch hardness, which improved from < 1.5 to > 2 kg, gloss (100-135) Specific gravity (0.92-0.96) and also chemical resistance test which passed for water, acid, and solvent except alkali, was poor because of the hydrolyzable ester group in the alkyd and PEA resins. The anti-corrosive features of the nanocomposites were investigated through salt spray tests in 5 wt % NaCl. The results indicate that well-dispersed bio ZnO and CuO/ZnO) NPs (1.0%) in the interior of the hyperbranched alkyd and PEA matrix improve the durability and anticorrosive attributes of the composites, such as degree of rusting, which ranged from 5 to 9, blistering size ranged from 6 to 9, and finally, scribe failure, which ranged from 6 to 9 mm. Thus, they exhibit potential applications in eco- friendly surface coatings. The anticorrosion mechanisms of the nanocomposite alkyd and PEA coating were attributed to the synergistic effect of bio ZnO and (CuO/ZnO) NPs and the prepared modified resins are highly rich in nitrogen elements, which might be regarded as a physical barrier layer for steel substrates.

Bio-fabrication of Selenium Nanoparticles Using Baker's Yeast Extract and Its Antimicrobial Efficacy on Food Borne Pathogens.

In the current study, selenium nanoparticles (SeNPs) were biosynthesized via extract of baker's yeast (Saccharomyces cerevisiae) for a green, economic, and eco-friendly strategy. The biosynthesized SeNPs were characterized using UV-vis, XRD, FTIR, DLS, and TEM. The particulates showed a spherical morphology with diameters between 4 and 51 nm; FTIR studies on NPs show functional groups corresponding to metabolites (proteins), which reduces and stabilizes the nanoparticle. Antimicrobial efficacy of biosynthesized SeNPs against food borne pathogens was assessed. SeNPs showed promising antimicrobial action against food borne pathogens (Escherichia coli, Staphylococcus aureus, Aspergillus fumigatus, and Aspergillus niger) with a minimal inhibitory concentration (MIC) of 62.5, 125, 250, and 500 µg/mL against Staphylococcus aureus, Escherichia coli, Aspergillus fumigatus, and Aspergillus niger, respectively. In conclusion, the biosynthesized SeNPs using extract of baker's yeast are promising as a safe antimicrobial agent against food pathogens. Hence, the biosynthesized SeNPs using baker's yeast extract exhibit antimicrobial activities and could be a useful efficacious antimicrobial agent in the preservation of food and medical field.

Green and ecofriendly biosynthesis of selenium nanoparticles using Urtica dioica (stinging nettle) leaf extract: Antimicrobial and anticancer activity.

BACKGROUND/GOAL/AIM: Plant extract is affordable and does not require any particular conditions; rapid production of nanoparticles using plants offers more advantages than other approaches. Selenium nanoparticles (SeNPs) have received much attention in the last decade due to SeNPs diverse and different applications. Herein, this study aimed to biosynthesize SeNPs using aqueous extract of Urtica dioica leaf through green and ecofriendly method. Moreover to fully characterize SeNPs using different techniques, and to evaluate it for antimicrobial activity as well as anticancer activity. MAIN METHODS AND MAJOR RESULTS: SeNPs were biosynthesis using aqueous leaf extract of U. dioica (stinging nettle). The biosynthesized SeNPs were characterized using UV-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive electron spectroscopy (EDX), transmission electron microscopy (TEM), and thermal-gravimetric analysis (TGA). Antimicrobial and anticancer activities of biosynthesized SeNPs were assessed. Results illustrated that SeNPs exhibited promising antibacterial activity against Gram-positive and Gram-negative bacteria, as well as unicellular and multi-cellular fungi. Moreover, minimal-inhibitory concentration (MIC) of SeNPs against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus were 250, 31.25, and 500 µg mL-1 , respectively, while were 62.5, 15.62, 31.25, and 7.81 µg mL-1 against Candida albicans, Aspergillus fumigatus, Aspergillus niger, and Aspergillus flavus, respectively. The cytotoxicity of SeNPs was performed on Vero normal-cell line CCL-81, where IC50 was 173.2 µg mL-1 . CONCLUSIONS AND IMPLICATIONS: For the first time, aqueous stinging nettle leaf extract was utilized to biosynthesize SeNPs in a green method. SeNPs have outstanding antimicrobial-activity against pathogenic bacterial and fungal strains. Moreover, SeNPs have promising anticancer activity against HepG2 cancerous cell line without cytotoxicity on Vero normal cell line. Finally, the biosynthesized SeNPs via aqueous extract of stinging nettle leaf exhibited potential antibacterial, antifungal, and anticancer action, making them useful in the medical field.

Synthesis of Chitosan-Based Gold Nanoparticles: Antimicrobial and Wound-Healing Activities.

The global spread of multidrug-resistant bacteria has become a significant hazard to public health, and more effective antibacterial agents are required. Therefore, this study describes the preparation, characterization, and evaluation of gold nanoparticles modified with chitosan (Chi/AuNPs) as a reducing and stabilizing agent with efficient antimicrobial effects. In recent years, the development of an efficient and ecofriendly method for synthesizing metal nanoparticles has attracted a lot of interest in the field of nanotechnology. Colloidal gold nanoparticles (AuNPs) were prepared by the chemical reduction of gold ions in the presence of chitosan (Chi), giving Chi/AuNPs. The characterization of Chi/AuNPs was carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and X-ray diffraction (XRD). Chi/AuNPs appeared spherical and monodispersed, with a diameter ranging between 20 to 120 nm. The synergistic effects of AuNPs and Chi led to the disruption of bacterial membranes. The maximum inhibitory impact was seen against P. aeruginosa at 500 µg/mL, with a zone of inhibition diameter of 26 ± 1.8 mm, whereas the least inhibitory effect was reported for S. aureus, with a zone of inhibition diameter of 16 ± 2.1 mm at the highest dose tested. Moreover, Chi/AuNPs exhibited antifungal activity toward Candida albicans when the MIC was 62.5 µg/mL. Cell viability and proliferation of the developed nanocomposite were evaluated using a sulphorhodamine B (SRB) assay with a half inhibitory concentration (IC50) of 111.1 µg/mL. Moreover, the in vitro wound-healing model revealed that the Chi/AuNP dressing provides a relatively rapid and efficacious wound-healing ability, making the obtained nanocomposite a promising candidate for the development of improved bandage materials.

Pseudomonas indica-Mediated Silver Nanoparticles: Antifungal and Antioxidant Biogenic Tool for Suppressing Mucormycosis Fungi.

Mucormycosis is considered one of the most dangerous invasive fungal diseases. In this study, a facile, green and eco-friendly method was used to biosynthesize silver nanoparticles (AgNPs) using Pseudomonas indica S. Azhar, to combat fungi causing mucormycosis. The biosynthesis of AgNPs was validated by a progressive shift in the color of P. indica filtrate from colorless to brown, as well as the identification of a distinctive absorption peak at 420 nm using UV-vis spectroscopy. Fourier-transform infrared spectroscopy (FTIR) results indicated the existence of bioactive chemicals that are responsible for AgNP production. AgNPs with particle sizes ranging from 2.4 to 53.5 nm were discovered using transmission electron microscopy (TEM). Pattern peaks corresponding to the 111, 200, 220, 311, and 222 planes, which corresponded to face-centered cubic forms of metallic silver, were also discovered using X-ray diffraction (XRD). Moreover, antifungal activity measurements of biosynthesized AgNPs against Rhizopus Microsporus, Mucor racemosus, and Syncephalastrum racemosum were carried out. Results of antifungal activity analysis revealed that the biosynthesized AgNPs exhibited outstanding antifungal activity against all tested fungi at a concentration of 400 µg/mL, where minimum inhibitory concentrations (MIC) were 50, 50, and 100 µg/mL toward R. microsporus, S. racemosum, and M. racemosus respectively. In addition, the biosynthesized AgNPs revealed antioxidant activity, where IC50 was 31 µg/mL when compared to ascorbic acid (0.79 µg/mL). Furthermore, the biosynthesized AgNPs showed no cytotoxicity on the Vero normal cell line. In conclusion, the biosynthesized AgNPs in this study can be used as effective antifungals with safe use, particularly for fungi causing mucormycosis.