Production Of AgNPs Research Articles

A Novel Electrochemical Modification Combined with Heat Treatment for Production of Ag NPs and Efficient Antibacterial Ag NPs-Coated Nonwoven Fabrics

Silver nanoparticles (Ag NPs) were quick synthesized by electrochemical method combined with heat treatment using silver electrodes and trisodiumcitrate (TSC) as reducing agent. This method is highly productive, with simple equipment, which is easily deployed on an industrial scale. The size of the Ag NPs is controlled through the amperage and the concentration of TSC. The effect of the synthesis' conditions on optical properties of Ag NPs was surveyed. The Ag NPs were used to fabricate the Ag NPs-coated nonwoven fabrics. The bactericidal testing showed that Ag NPs-coated nonwoven fabrics were able to kill over 80% of E. coli and 96.9% of B. subtilis bacteria. These results can be considered as a new choice to prevent the spread of diseases caused by bacteria and viruses, thereby contributing to the protection of human health.

Optimization Effect on Green Synthesis of Silver Nanoparticles (AgNPs) Using Dimrit Raisin Extract and Their Antimicrobial Activity

This paper describes the simple and environmentally friendly production of AgNPs using Dimrit raisin, grown in Burdur, extract. To optimize the synthesis of AgNPs, a number of variables, including extract concentration, silver solution concentration, synthesis time, and synthesis temperature, were investigated. AgNPs were obtained after 173 h at 1% extract concentration and 10-1 M silver concentration. The structure of the synthesised AgNPs was investigated by Transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). TEM analysis showed that the majority of the AgNPs had a spherical shape, and the average particle size was 30 nm. Antimicrobial activity was seen against Staphylococcus aureus ATTC43300, Enterococcus faecalis ATTC29212, Bacillus subtilis, Listeria monocytogenes, Klebsiella pneumoniae and Gram-negative Salmonella enterocolitis, E. coli 0157:H7 ATTC 43895, and Escherichia coli ATTC 35150.

Optimizing the Bio-Synthesis of Silver and Ferrous Oxide Nanoparticles Using Marsilea quadrifolia (L.) Leaf Extract

Bio-mediated nanoparticle synthesis is a ‘green’ environmental friendly process. The present study investigates bio-synthesis of silver (Ag) nanoparticles (NPs) and Ferrous Oxide (FeO) nanoparticles using leaf extract of Marsilea quadrifolia, a noxious weed in rice fields worldwide. Optimal synthesis of AgNPs and FeONPs with desirable concentrations of Silver Nitrate and Ferrous Nitrate and different quantities of the plant extract was investigated under room temperature. Characterization of NPs was carried out using ultraviolet–visible spectroscopy, (SEM) Scanning Electron Microscope. To determine the appropriate concentrations for AgNPs and FeONPs synthesis, different dilution series of Silver Nitrate and Ferrous Nitrate were reacted with M. quadrifolia leaf extract at 1:1, 1:2, 1:3 ratios respectively, under room temperature condition. For the extraction, 8g of M. quadrifolia dried leaf samples were used and extraction was done by using deionized water. The results showed that plant extract and salt mixed ratios have a significant effect on yield of synthesized AgNPs and FeONPs. The best ratio of plant extract and AgNO3 is 1:1 to optimize the production of AgNPs. The temperature range 60-80oC promotes higher AgNPs production comparative to the room temperature. Similar observations were recorded with FeONPs. M. diplotricha leaf extract is an effective source for AgNPs and FeONPs production.

Biosynthesis of silver nanoparticles using nitrate reductase from Aspergillus terreus N4 and their potential use as a non-alcoholic disinfectant.

Green technology has been developed for the quick production of stabilized silver nanoparticles (AgNPs), with the assistance of nitrate reductase from an isolated culture of Aspergillus terreus N4. The organism's intracellular and periplasmic fractions contained nitrate reductase, with the former demonstrating the highest activity of 0.20 IU/g of mycelium. When the fungus was cultivated in a medium comprising 1.056% glucose, 1.836% peptone, 0.3386% yeast extract, and 0.025% KNO3, the greatest nitrate reductase productivity of 0.3268 IU/g was achieved. Statistical modeling via response surface methodology was used to optimize the enzyme production. The periplasmic and intracellular enzyme fractions were found to convert Ag+ to Ag0, initiating synthesis within 20min, with predominant nanoparticle sizes between 25 and 30nm. By normalizing the effects of temperature, pH, AgNO3 concentration, and mycelium age with a variable shaking period for enzyme release, the production of AgNPs with the periplasmic fraction was optimized. The synthesis of nanoparticles occurred at temperatures of 30, 40, and 50°C, with the highest yield observed at 40 and 50°C during shorter incubation periods. Similarly, the nanoparticles were synthesized at pH levels of 7.0, 8.0, and 9.0, with the greatest production observed at pH 8.0 and 9.0 at lower incubation periods. The antimicrobial activity of AgNPs was demonstrated against common foodborne pathogens, including Staphylococcus aureus and Salmonella typhimurium, indicating their potential as non-alcoholic disinfectants.

Biosynthesis of Silver Nanoparticles Using Tabernaemontana ventricosa Extracts

Nanoscience and nanotechnology have been rapidly developing due to the increased use of nanoparticles in several fields including health (antibacterial agents), medicine, chemistry, food, textiles, agricultural sectors, and nanofluids. The study aimed to biologically synthesize AgNPs using leaf and stem extracts of Tabernaemontana ventricosa. The AgNPs were successfully synthesized and verified using UV-visible spectroscopy; however, the synthesis of the AgNPs was more efficient using the leaf extracts rather than the stem extracts. The energy-dispersive X-ray (EDX) analysis showed that the elemental silver (Ag) content was much higher using leaf extracts compared to the stem extracts. The AgNPs synthesized using both leaf and stem extracts were analyzed using scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), and images displayed spherical, ovate, and triangular-shaped nanoparticles (NPs), which varied in particle size ranging from 16.06 ± 6.81 nm to 80.26 ± 24.93 nm across all treatments. However, nanoparticle tracking analysis (NTA) displayed much larger particle sizes ranging from 63.9 ± 63.9 nm to 147.4 ± 7.4 nm. The Fourier transform infrared (FTIR) spectral analysis observed functional groups such as alcohols, phenolic compounds, aldehydes, alkanes, esters, amines, and carboxylic acids. Our study suggests that medicinal plant extracts can be used for the effective economical production of AgNPs due to their efficient capping; however, further studies are necessary to determine the possible function groups and phytochemicals within T. ventricosa that are responsible for the synthesis of AgNPs.

Green Synthesized Silver Nanoparticles: A Potential Antibacterial Agent, Antioxidant, and Colorimetric Nanoprobe for the Detection of Hg2+ Ions.

Silver nanoparticles (AgNPs) prepared by green synthesis have a lot of potentials in various fields. Among them,as an antioxidant, antibacterial agent, and nanoprobe for the colorimetric detection of mercury (Hg2+) ions is thought to be the most important. The antibacterial, antioxidant, and colorimetric sensing potential of the greenly produced AgNPs utilizingPiper chabastem extract are all predicted in this investigation. By using the disc diffusion method, the antibacterial activity of greenly produced AgNPs are assessed, and the findings are measured from the zone of inhibition (ZOI). It is revealed that theStaphylococcus aureus, Micrococcus spp., Escherichia coli,andPseudomonas aeruginosabacterial strains are significantly resisted by the greenly produced AgNPs. The antioxidant activity test of AgNPs reveals a considerable impact on free radical scavenging havingthe inhibitory concentration (IC 50) is 1.13mL (equivalent to 0.45mg mL-1). Also, with a low limit of detection of 28ppm, the resulting AgNPs are used as highly selective and economical colorimetric sensors for Hg2+detection. The study's findings support the hypothesis thatPiper chabastems can serve as a source for the production of AgNPs with high antibacterial and antioxidant activity and usefulness for simple colorimetric readings of Hg2+.

Green Synthesis of Silver Nanoparticles

Development of reliable and eco-accommodating methods for the synthesis of nanoparticles is a vital step in the field of nanotechnology. The remarkable chemical, physical, and biological characteristics of silver nanoparticles make them significant. Nowadays, due to the growing demand for environmentally benign technology for material synthesis, biosynthesis of silver nanoparticles (Ag Nps) has attracted a lot of attention in industrialized nations. Among the various types of nanoparticles and their strategy for synthesis, because of their special physicochemical and biological characteristics, silver nanoparticles created through green synthesis have drawn considerable interest in the biomedical, cellular imaging, cosmetics, drug delivery, food, and agrochemical industries. The size distributions and resultant nanostructure studies from the transmission electron microscopy (TEM) were in perfect agreement with the characteristics of the synthesized colloidal Ag-NPs analyzed by the ultraviolet-visible (UV-vis) spectra. For the creation of silver nanoparticles (AgNPs), biomolecules from various plant parts and microbial species have been investigated. In this review, the available previously released information on AgNPs production, characterisation methods, and applications are compiled and critically analyzed.

Extraction and Phytochemical Profile of Three Herbal Weeds: Chromolaena odorata L., Amaranthys virdis L., and Cyperus Rotudus L. for Green Synthesis of Silver Nanoparticles

Phytochemical screening and silver nanoparticle synthesis of extract of 3 local weeds from Sakon Nakhon Province, namely, Chromolaena odorata L., Amaranthus virdis L., and Cyperus Rotudus L., were carried out. The preliminary testing of chemical constituents revealed secondary metabolites with pharmacological activity. The weed extracts possessed bioactive compounds and were potent for silver nanoparticle synthesis. The weed extracts demonstrated a lower inhibition percentage (DPPH inhibition) than ascorbic acid, with significant differences at p<0.05. Reducing agent analysis revealed that the weed extracts contained reducing compounds such as phenol and carboxylic acid suitable for AgNPs. The XRD patterns of silver nanoparticles synthesized from the extracts demonstrated the efficacy of the weed extract for medical applications (the production of AgNPs). In the future, the size and morphology of silver particles should be investigated. The current results are expected to be a guideline for further applications of local weeds.

Biosynthesis and Characterization of Silver Nanoparticles Produced by Parachlorella kessleri and Cyclotella spp., and the Evaluation of Their Antibacterial Activity.

Green synthesis is one of the fastest and best ways for ecofriendly nanoparticle synthesis. This study aims to investigate the use of the green microalgae Parachlorella kesseleri and Cyclotella spp. for the biological synthesis of silver nanoparticles (AgNPs). This work focuses on optimizing various parameters necessary for the production and stability of AgNPs. The nanoparticle formation was confirmed by UV-Visible analysis, which revealed the surface plasmon resonance band at 420 nm. The characterization of the AgNPs was performed using UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The antimicrobial properties of these bioactive AgNPs were also tested, showing excellent antibacterial activity against six bacterial strains, Escherichia coli, multidrug-resistant Escherichia coli, Bacillus clausii, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhi. The biosynthesis of AgNPs from living cultures of microalgae has remarkable antibacterial properties. Other studies are underway in our laboratory to clarify the mechanism of the biosynthesis of these nanoparticles, and their action on bacteria.

Bio‐fabrication of Silver Nanoparticles Using Alysicarpus vaginalis Extract: Preparation, Characterization and Comparative in vitro Antibacterial Evaluations

AbstractGreen synthesis of silver nanoparticles (AgNPs) using the Alysicarpus vaginalis alcoholic extract as a reducing agent and a capping ligand was carried out. Notable peaks of λmax 442–602 nm indicated the reduction of silver ions to elemental AgNPs. Particle size (Zavg) was in the range of 32.3±0.76 to 252.3±0.342 nm). The negative Zeta potential (ZP, −2.9±0.31 to −21.7±0.13 mV) and low polydispersity index (PDI, 0.181±0.02 to 0.635±0.02) supported the homogeneous nature of AgNPs. Further, crystalline spherical nature of AgNPs with a smooth surface was confirmed by high‐resolution transmission electron microscopy (HRTEM) studies. The AgNPs showed 1.2 to 1.4‐fold enhanced antibacterial activity than extract (6–10 mm zone of inhibition) against Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, and Salmonella enterica ser. Typhi by disc diffusion assay. The AgNP formulation F9 showed equal (against Gram‐positive L. monocytogenes) or even better (against Gram‐negative S. enterica Typhi) antimicrobial activity than the positive control, ciprofloxacin. Further investigations on F9 are suggested in order to develop a broad‐spectrum, cost‐effective antibacterial formulation of natural origin. This study represents a significant step forward in the field of bio‐fabrication and presents a promising alternative to traditional chemical synthesis methods for the production of antimicrobial AgNPs.

Bioinspired 5-caffeoylquinic acid capped silver nanoparticles using Coffee arabica leaf extract for high-sensitive cysteine detection

Selection of plant extracts as bioactive phytochemical source to synthesize nanoparticles is highly demanding due to the biocompatibility, nontoxicity, and cost-effectiveness over other available physical and chemical methods. Here, for the first time, Coffee arabica leaf extracts (CAE) were used to produce highly stable silver nanoparticles (AgNPs) and the corresponding bio reduction, capping and stabilization mechanism mediated by dominant isomer 5-caffeoylquinic acid (5-CQA) is discussed. UV–Vis, FTIR, μRaman spectroscopy, TEM, DLS and Zeta potential analyzer measurements were employed to characterize these green synthesized NPs. The affinity of 5-CQA capped CAE–AgNPs to thiol moiety of amino acid is utilized for the selective as well as sensitive detection of L-cysteine (L-Cys) to a low detection limit of 0.1 nM, as obtained from its μRaman spectra. Hence, the proposed novel, simple, eco-friendly, and economically sustainable method can provide a promising nanoplatform in the field of biosensors compliant with large-scale industrial production of AgNPs without aid of further instrumentation.

Studies on phytochemical, mineral content, in vitro anti-urolithiatic and anti-diabetic activities of horse gram flour extracts and its biosynthesized Ag nanoparticles

The current study aims to examine the use of horse gram flour and its extracts as a low-cost source of mineral content with anti-urolithiatic, anti-diabetic properties and to compare the biological activities with its biosynthesized AgNPs. The secondary metabolites and the macro and micronutrients present in the selected herbal product, reinforces the utility of the horse gram as a promising herbal. Present investigation reveals that the biomass chosen for the study as a cheap natural source with valuable mineral content of calcium (43.06 mg/L), followed by potassium (13.78 mg/L) and sodium (6.94 mg/L). The grain's water extracts found to contain carbohydrate as dominating component with the value of (65.10 ± 0.95 mg g−1 equivalent). Whereas both water and ethanol extract contain TPC (phenol) viz; 60.13 ± 2.45 mg g−1, 68.24 ± 1.33 mg g−1, TTC (terpenoids)53.21 ± 1.4 mg g−1,51.27 ± 2.65 mg g−1, followed by TSC (sterol)as 45.58 ± 1.7 mg g−1, 57.27 ± 1.65 mg g−1 in moderate amounts respectively. The aqueous extract of Horse gram was used for the synthesis the AgNPs through a straightforward green approach and characterized by FESEM, TEM, zeta potential, X-ray diffraction, UV spectroscopy and particle size measurement. These studies demonstrate the production of AgNPs with an average particle size of 30 nm–60 nm. Investigation on anti-urolithiatic property with aqueous extract, (HGW), ethanol extract (HGE) and its biosynthesized Ag nanoparticles (HG-Ag) reveal that, among the three samples chosen, the biosynthesized Ag nanoparticles possess the best inhibiting activity. The disintegration of crystals in gel medium further validated the extracts and Ag nanoparticles crystal growth inhibitory activity, at concentrations of 2% for extracts and 200 μg/ml for AgNPs. Further, it is also found that the HG-Ag nanoparticle exhibit good anti-diabetic activity (75.36%) than the other two extracts (HGW Extract-67.18% & HGE Extract-44.29%). Thus, the seed flour extracts and its AgNps demonstrated to be a promising natural herbal product with potential mineral content, antidiabetic and anti-urolithiatic activities which could be a used as a value-added product in the dietary formulations.

Terminalia chebula-Assisted Silver Nanoparticles: Biological Potential, Synthesis, Characterization, and Ecotoxicity.

In the current research, an aqueous extract of Terminalia chebula fruit was used to produce silver nanoparticles (Ag NPs) in a sustainable manner. UV-visible spectrophotometry, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the synthesized nanoparticles. Synthesized Ag NPs were detected since their greatest absorption peak was seen at 460 nm. The synthesized Ag NPs were spherical and had an average size of about 50 nm, with agglomerated structures, as shown via SEM and TEM analyses. The biological activities of the synthesized Ag NPs were evaluated in terms of their antibacterial and antioxidant properties, as well as protein leakage and time-kill kinetics assays. The results suggest that the green synthesized Ag NPs possess significant antibacterial and antioxidant activities, making them a promising candidate for therapeutic applications. Furthermore, the study also evaluated the potential toxicological effects of the Ag NPs using zebrafish embryos as a model organism. The findings indicate that the synthesized Ag NPs did not induce any significant toxic effects on zebrafish embryos, further supporting their potential as therapeutic agents. In conclusion, the environmentally friendly production of Ag NPs using the extract from T. chebula is a promising strategy for discovering novel therapeutic agents with prospective uses in biomedicine.

Multifunctional Lipophobic Polymer Dots from Cyclodextrin: Antimicrobial/Anticancer Laborers and Silver Ions Chemo-Sensor.

β-Cyclodextrin (CD) is currently exploited for the implantation of lipophobic polymer dots (PDs) for antimicrobial and anticancer laborers. Moreover, the PDs were investigated to act as a chemo-sensor for metal detection. The data revealed that under basic conditions, photoluminescent PDs (5.1 nm) were successively clustered with a controllable size at 190 °C, whereas under acidic conditions, smaller-sized non-photoluminescent carbon nanoparticles (2.9 nm) were obtained. The fluorescence intensity of synthesized PDs under basic conditions was affected by pH, and such an intensity was significantly higher compared to that prepared under acidic conditions. The PDs were exploited as florescent detectors in estimation of Ag+ ions in aquatic streams. Treatment of Ag+ ion colloids with PDs resulted in fluorescence quenching attributing to the production of AgNPs that approved by spectral studies. The cell viability percent was estimated for Escherichia coli, Staphylococcus aureus, and Candida albicans after incubation with PDs implanted under basic conditions for 24 h. The cell mortality percent was estimated for breast cancer (MCF-7) after incubation with different concentrations of PDs that were implanted under acidic versus basic conditions to show that treatment of the tested cells with 1000 μg/mL PDs prepared under basic (IC50 232.5 μg/mL) and acidic (IC50 88.6 μg/mL) conditions resulted in cell mortality percentages of 70 and 90%, respectively.

Antioxidant, antibacterial, and cytotoxicity potential of synthesized silver nanoparticles from the Cassia alata leaf aqueous extract

Abstract The current research focuses on the silver nanoparticles (AgNPs) synthesis from the Cassia alata aqueous leaf extract. Various production parameters like pH (4, 5, 6, 7, 8, 9, and 10), metal ion concentration (1, 2, 3, 4, and 5 mM), and substrate (leaf extract) concentration (0.5, 1, 1.5, 2 and 2.5 mL) were optimized. UV-visible spectroscopy was used to identify the production by scanning the wavelength from 200 to 800 nm. Visual color change from light green to brown was designated as prior confirmation of the AgNP production. Physical characterization of AgNPs was carried out using scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray energy-dispersive spectroscopy, and X-ray diffraction. Furthermore, the obtained AgNPs show significant antibacterial activity for Staphylococcus aureus, Pseudomonas sp. Klebsiella sp., Proteus sp., and Enterobacter sp. The antioxidant potential was determined by α,α-diphenyl-β-picrylhydrazyl assay and cytotoxicity by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction assay on human lung cancer cell lines (A549). AgNPs confirmed potent antibacterial activity against skin infections, demonstrating their medicinal significance and are therefore crucial for creating a medicinal formulation with antibacterial properties.

Biosynthesis of silver nanoparticles (Ag-NPs) using Senna alexandrina grown in Saudi Arabia and their bioactivity against multidrug-resistant pathogens and cancer cells

There is no doubt that the risk of drug-resistant pathogens and cancer diseases is on the rise. So, the goal of this study was to find out how effective silver nanoparticles (Ag-NPs) made by Senna alexandrina are at fighting these threats.In this work, S. alexandrina collected from Medina, Saudi Arabia was used and the biosynthesis method was applied to produce the Ag-NPs. The characterization of Ag-NPs was done using different analytical techniques, including UV spectroscopy, FT-IR, TEM, and XRD analysis. The MIC, MBC, and MTT protocols were applied to confirm the bioactivity of the Ag-NPs as antibacterial and anticancer bioagents. The findings reported indicating that the aqueous extract of S. alexandrina leaves, grown naturally in Saudi Arabia, is ideal for the production of bioactive Ag-NPs. The hydroxyl, aliphatic, alkene, N–H bend of primary amines, C–H bonds, and C-O bonds of alcohol were detected in this product. The small, sphere-shaped particles (4–7 nm) were the most prevalent among the bioactive Ag-NPs produced in this work. These nanoparticles inhibited some important multidrug-resistant pathogens (MDRPs) (Escherichia coli, Acinetobacter baumanii/haemolyticus, Staphylococcus epidermidis, and Methicillin-resistant Staphylococcus aureus (MRSA)), as well as their ability to inhibit breast cancer cells (MCF-7 cells). The MIC of Ag-NPs ranged from 0.03 to 0.6 mg/mL, while their MBC ranged from 0.06 to 2.5 mg/mL.Anticancer activity test showed that IC50 of the Ag-NPs against tested breast cancer cells was 61.9 ± 3.8 µg/mL. According to the current results, biosynthesis using S. alexandrina leaves grown naturally in Saudi Arabia was an ideal technique for producing bioactive Ag-NPs that could be used to combat a variety of MDRPs and cancer diseases.

Evaluation of Antibacterial and Anticancer Characteristics of Silver Nanoparticles Synthesized from Plant Extracts of Wrightia tinctoria and Acacia chundra.

The study showed the ability to synthesize environmentally friendly silver nanoparticles (AgNPs) using extracts from Wrightia tinctoria seeds and Acacia chundra stems. Surface plasmon resonance peaks in the UV-Vis absorption spectra of both plant extracts verified AgNP synthesis. The structural and morphological properties of the AgNPs were investigated using analytical techniques such as XRD, FTIR, TEM, and EDAX. The AgNPs have an FCC crystalline structure, according to XRD study, and their sizes range from 20 to 40 nm, according to TEM images. Based on the results, these plant extracts have been identified as suitable bioresources for AgNP production. The study also showed that both AgNPs had significant levels of antibacterial activity when tested on four different microbial strains using the agar-well diffusion method. The bacteria tested included two Gram-positive strains (Staphylococcus aureus and Micrococcus luteus) and two Gram-negative strains (Proteus vulgaris and Escherichia coli). Furthermore, the AgNPs were found to have a significant anticancer effect on MCF-7 cell lines, suggesting that they may be useful in therapeutic applications. Overall, this research highlights the potential of the plant extracts considered as a source for synthesizing eco-friendly AgNPs with potential applications in medicine and other fields.

Pluronic® F127 Hydrogel Containing Silver Nanoparticles in Skin Burn Regeneration: An Experimental Approach from Fundamental to Translational Research.

Presently, skin burns are considered one of the main public health problems and lack therapeutic options. In recent years, silver nanoparticles (AgNPs) have been widely studied, playing an increasingly important role in wound healing due to their antibacterial activity. This work is focused on the production and characterization of AgNPs loaded in a Pluronic® F127 hydrogel, as well as assessing its antimicrobial and wound-healing potential. Pluronic® F127 has been extensively explored for therapeutic applications mainly due to its appealing properties. The developed AgNPs had an average size of 48.04 ± 14.87 nm (when prepared by method C) and a negative surface charge. Macroscopically, the AgNPs solution presented a translucent yellow coloration with a characteristic absorption peak at 407 nm. Microscopically, the AgNPs presented a multiform morphology with small sizes (~50 nm). Skin permeation studies revealed that no AgNPs permeated the skin after 24 h. AgNPs further demonstrated antimicrobial activity against different bacterial species predominant in burns. A chemical burn model was developed to perform preliminary in vivo assays and the results showed that the performance of the developed AgNPs loaded in hydrogel, with smaller silver dose, was comparable with a commercial silver cream using higher doses. In conclusion, hydrogel-loaded AgNPs is potentially an important resource in the treatment of skin burns due to their proven efficacy by topical administration.

Green Synthesis of Silver Nanoparticles Using Nigella sativa Callus and Cellular Suspension Cultures with Different pH Values

The current study included an extensive protocol for the first time globally. This protocol was concerned with the green synthesis of silver nanoparticles (AgNPs) from Nigella sativa callus and cellular suspended cultures. The results confirmed the success of the process of green synthesis of AgNPs from Nigella sativa callus by the color change in the reaction solution from colorless to brown and reddish-brown as a result of the reduction of Ag ions in the extract after addition of AgNO3 solution (1:1 v/v). UV-Vis spectroscopy was used to initially prove the existence of AgNPs, which showed an absorption peak ranging between (420-440 nm) caused by the phenomenon of Surface Plasmon Resonance (SPR) of AgNPs. (SEM) showed nanoparticle objects ranging from (18.341 - 40.932) nm for standard extracts and (17.261 - 29.13) nm for suspended cultures extracts. (EDX) proved the success of producing AgNPs in different proportions depending on the type of tissue cultures used and the difference in the pH value of the extracts (6, 9, 12), as the highest % of AgNPs production reached 4.46% in suspended cultures extracts from pH 12, followed by callus extracts, which reached 4.12% at pH 12. biologically prepared AgNPs proved their effectiveness in inhibiting the growth of Gram+ and Gram- bacteria, as the inhibition zone ranged (19– 35 mm) depending on the type of extract and the degree of acidity (pH) applied to the extract.

Biogenic Synthesis and Characterization of Silver Nanoparticles (AgNPs) Produced by Indigenous Microorganisms Isolated from Banana (Musa spp) Soils

This research focused on the screening of indigenous microorganisms isolated from banana soils for their capability to synthesize silver nanoparticles (AgNPs) extracellularly. Ninety-five isolates were screened for AgNP production. The cell-free extracts of these isolates were added to silver nitrate (AgNO3) aqueous solution and were observed for color changes from original pale yellow to dark brown. Ten isolates (3 bacteria and 7 fungi) were found capable of producing AgNPs. Bacterial isolates B2, B3, and B5 were molecularly identified as Bacillus aryabhattai, Priestia megaterium, and B. megaterium, respectively. The AgNPs produced by these bacterial isolates were circular and showed an absorbance peak at approximately 420 nm. On the other hand, the fungal isolates F2, F3, and F43 were molecularly identified as Penicilliumcitrinum, P. glaucoroseum, and P. oxalicum. The AgNPs produced by the Penicillium spp were aggregated, circular and showed absorbance peaks at 420 nm. The other four fungal isolates, F7, F24, F29, and F40, were identified as Aspergillus flavus, A. terreus, and A. japonicum (F29 and F40), respectively. The AgNPs produced by the Aspergillus spp. were circular and showed absorbance peaks between 420 nm and 450 nm. The continuous search for novel isolates that can carry out the biogenic synthesis of AgNPs remains the focus of nanotechnological research. This study confirms microorganisms of Bacillus, Penicillium, and Aspergillus genera can effectively biosynthesize AgNPs.