Hybrid Materials Obtained by Immobilization of Biosynthesized Ag Nanoparticles with Antioxidant and Antimicrobial Activity.

Ag nanoparticles (AgNPs) were biosynthesized using sage (Salvia officinalis L.) extract. The obtained nanoparticles were supported on SBA-15 mesoporous silica (S), before and after immobilization of 10% TiO2 (Degussa-P25, STp; commercial rutile, STr; and silica synthesized from Ti butoxide, STb). The formation of AgNPs was confirmed by X-ray diffraction. The plasmon resonance effect, evidenced by UV-Vis spectra, was preserved after immobilization only for the sample supported on STb. The immobilization and dispersion properties of AgNPs on supports were evidenced by TEM microscopy, energy-dispersive X-rays, dynamic light scattering, photoluminescence and FT-IR spectroscopy. The antioxidant activity of the supported samples significantly exceeded that of the sage extract or AgNPs. Antimicrobial tests were carried out, in conditions of darkness and white light, on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Higher antimicrobial activity was evident for SAg and STbAg samples. White light increased antibacterial activity in the case of Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). In the first case, antibacterial activity increased for both supported and unsupported AgNPs, while in the second one, the activity increased only for SAg and STbAg samples. The proposed antibacterial mechanism shows the effect of AgNPs and Ag+ ions on bacteria in dark and light conditions.

Film dressings from Thai mango seed kernel extracts versus nanocrystalline silver dressings in antibacterial properties.

Introduction: The extract from the Mango Seed Kernel (MSK) has been documented to exhibit antibacterial activity against Gram-positive and Gram-negative bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa. This suggests that biomaterials containing MSK extract could be a viable alternative to conventional wound treatments, such as nanocrystalline silver dressings. Despite this potential, there is a notable gap in the literature regarding comparing the antibacterial effectiveness of MSK film dressings with nanocrystalline silver dressings. This study aimed to develop film dressings containing MSK extract and evaluate their antibacterial properties compared to nanocrystalline silver dressings. Additionally, the study aimed to assess other vital physical properties of these dressings critical for effective wound care. Materials and methods: We prepared MSK film dressings from two cultivars of mango from Thailand, 'Chokanan' and 'Namdokmai'. The inhibition-zone method was employed to determine the antibacterial property. The morphology and chemical characterization of the prepared MSK film dressings were examined with scanning electron microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR), respectively. The absorption of pseudo-wound exudate and water vapor transmission rate (WVTR) of film dressings were evaluated. Results: The results showed that 40% of MSKC film dressing had the highest inhibition zone (20.00 ± 0.00 mm against S. aureus and 17.00 ± 1.00 mm against P. aeruginosa) and 20%, 30%, and 40% of MSKC and MSKN film dressings had inhibition zones similar to nanocrystalline silver dressing for both S. aureus and P. aeruginosa (p > 0.05). In addition, all concentrations of the MSK film dressings had low absorption capacity, and Chokanan MSK (MSKC) film dressings had a higher WVTR than Namdokmai MSK (MSKN) film dressings. Conclusion: 20%, 30%, and 40% of MSK film dressing is nearly as effective as nanocrystalline silver dressing. Therefore, it has the potential to be an alternative antibacterial dressing and is suitable for wounds with low exudate levels.

Untargeted metabolomics and molecular docking studies on green silver nanoparticles synthesized by Sarocladium subulatum: Exploring antibacterial and antioxidant properties.

The biological synthesis of silver nanoparticles (Ag-NPs) with fungi has shown promising results in antibacterial and antioxidant properties. Fungi generate metabolites (both primary and secondary) and proteins, which aid in the formation of metal nanoparticles as reducing or capping agents. While several studies have been conducted on the biological production of Ag-NPs, the exact mechanisms still need to be clarified. In this study, Ag-NPs are synthesized greenly using an unstudied fungal strain, Sarocladium subulatum AS4D. Three silver salts were used to synthesize the Ag-NPs for the first time, optimized using a cell-free extract (CFE) strategy. Additionally, these NPs were assessed for their antimicrobial and antioxidant properties. Various spectroscopic and microscopy techniques were utilized to confirm Ag-NP formation and analyze their morphology, crystalline properties, functional groups, size, stability, and concentrations. Untargeted metabolomics and proteome disruption were employed to explore the synthesis mechanism. Computational tools were applied to predict metabolite toxicity and antibacterial activity. The study identified 40 fungal metabolites capable of reducing silver ions, with COOH and OH functional groups playing a pivotal role. The silver salt type impacted the NPs' size and stability, with sizes ranging from 40 to 52 nm and zeta potentials from -0.9 to -30.4 mV. Proteome disruption affected size and stability but not shape. Biosynthesized Ag-NPs using protein-free extracts ranged from 55 to 62 nm, and zeta potentials varied from -18 to -27 mV. Molecular docking studies and PASS results found no role for the metabolome in antibacterial activity. This suggests the antibacterial activity comes from Ag-NPs, not capping or reducing agents. Overall, the research affirmed the vital role of specific reducing metabolites in the biosynthesis of Ag-NPs, while proteins derived from biological extracts were found to solely affect their size and stability.

Synthesis of bio-stabilized silver nanoparticles using Roccella montagnei, their anticandidal capacities & potential to inhibit the virulence factors in fluconazole-resistant Candida albicans.

Candida species is the causative agent in approximately 80% of invasive mycoses and drug-resistant Candida albicans is among the four strains of 'critical priority group' framed by WHO. Lichens are endowed with some rare phytochemicals and a plethora of therapeutics viz. antifungal capacities of Roccella montagnei. Biosynthesis of silver nanoparticles (AgNPs) using lichen could offer an eco-friendly, and cost-effective alternative against emerging 'microbial resistance.' Therefore, the objective was to biosynthesize silver nanoparticles (Rm-AgNPs) using a Hydro-alcoholic (1:1) extract of R. montagnei to develop a potent anticandidal agent against Fluconazole-resistant C. albicans NBC099. UV-Spectroscopy identified AgNPs specific-peak of Rm-AgNPs at 420-440 nm and FTIR revealed the presence of amines, alcohol, aromatic compounds, and acids. SEM and TEM analysis indicated that Rm-AgNPs are spherical shaped with a size range of 10-50 nm. Zetasizer analysis indicated that particles are highly stable and have a mean hydrodynamic diameter of 116 nm with a zeta potential charge of - 41 mV. XRD analysis suggested face centered cubic crystal lattice structure. Results indicated that Rm-AgNPs strongly inhibited the growth of NBC099 at a minimum inhibitory concentration (IC50) of ≤ 15 µg. C. albicans culture treated with Rm-AgNPs at concentrations below IC50, down-regulates the production of different virulence factors in NBC099, viz. hyphal formation (> 85%), biofilms production (> 80%), phospholipase, esterase, proteinase activity. The apoptosis assay demonstrated the Rm-AgNPs induced apoptosis in NBC099 cells via oxidative stress. Interestingly, Rm-AgNPs showed negligible cytotoxicity (< 6%) in murine RAW 246.7 macrophage cells at a concentration above 15 µg/mL. Therefore, Rm-AgNPs have been offered as an anti-candida alternative that can be utilized to improve the efficacy of already available medications.

Silver nanoparticle-induced in vitro flowering in Dendrocalamus strictus (Roxb.) nees and genetic fidelity assessment of regenerants using molecular markers.

BACKGROUND: Dendrocalamus strictus (Roxb.) Nees, generally referred to as 'Male bamboo,' is a globally prevalent and highly significant species of bamboo. It is a versatile species and possesses notable industrial significance. However, despite its numerous applications, the production of this plant is insufficient to fulfill the worldwide demand. The challenges that impede the dissemination of D. strictus encompass the unpredictable blooming pattern (30-70 years), low seed production, and limited seed viability. Therefore, tissue culture presents a reliable and effective option for the mass production of standardized planting material. METHODOLOGY AND RESULTS: This study investigated the effects of silver nanoparticles (AgNPs) at a concentration of 6.0 mg L- 1 in the Murashige and Skoog (MS) nutrient medium fortified with pre-optimized plant growth regulators (3.0 mg L- 1 6-benzylaminopurine + 0.5 mg L- 1 α-naphthalene acetic acid) on the induction of flowering in a controlled environment in D. strictus. The use of AgNPs in the media induced a maximum of 14 inflorescences per culture vessel, 9 flowers per inflorescence, and improved the performance of the micropropagated plantlets during acclimatization in the greenhouse and field. The ISSR and SCoT amplified polymorphic DNA analysis of the regenerants resulted in the formation of 49 bands (300 to 2000 bp size) and 36 scorable bands (350 to 2000 bp) respectively. All the PCR amplicons produced by SCoT and ISSR were monomorphic confirming the genetic uniformity of the tissue cultured plants of D. strictus with the mother plant. CONCLUSIONS: It can be inferred that the incorporation of AgNPs during the shoot proliferation phase has the potential to stimulate in vitro flowering in D. strictus. This finding could provide valuable insights into innovative strategies for enhancing crop productivity and genetic manipulation for accelerated breeding and agricultural advancement.

Comparative biotoxicity study for identifying better alternative insecticide especially green nano-emulsion which used as mosquitocides.

This research work was planned to test biosafety of different nanomaterials on the different animals models. These nanoparticles were previously used as potential insecticides of mosquito larvae. The biosafety of these nanoproducts were evaluated on certain organs of non target animals that associated with mosquito breeding sites in Egypt. Animal organs such as the kidneys of rats, toads, and the fish's spleen were used as models to study the biological toxicity of these nanomaterials. After 30 days of the animals receiving the nanomaterials in their water supply, different cell mediated immune cells were assessed in these tissues. Both TNF-α and BAX immuno-expression were also used as immunohistochemical markers. Histopathology was conducted to detect the effect of the tested nanoproducts at the tissue level of the liver and kidneys of both the rats and toads. Green nanoemulsion of the lavender essential oil was relatively more effective, safe, and biodegradable to be used as insecticides against mosquito larvae than the metal-based nanomaterials.

Antibacterial Property of Silver Nanoparticles Green Synthesized from Stachys schtschegleevii Plant Extract on Urinary Tract Infection Bacteria.

Urinary tract infections are one of the most common infections worldwide. Given the increasing antibiotic resistance, monitoring antibiotic sensitivity patterns is crucial. Furthermore, silver nanoparticles synthesized from Stachys schtschegleevii can exhibit potent antibacterial, antibiotic, and antifungal properties. The plant S. schtschegleevii was collected from its natural habitat, dried, and its extract was then exposed to silver nitrate. Under specific conditions, silver nanoparticles were synthesized from it. Subsequently, the production and validation of silver nanoparticles were confirmed through techniques such as FTIR analysis, UV-Vis analysis, TEM, SEM, EDX analysis, and zeta potential analysis. In the in vitro section of the research, the impact of the extracted silver nanoparticles on bacteria isolated from patients' urine and standard bacterial culture (control) was assessed using the disc diffusion and MIC test methods. The results of the analyses are FTIR (high protein content; proteins and phenols serve as stabilizing agents), UV-Vis (peak of 460 nm), TEM (spherical to occasionally elliptical shapes), SEM (sizes: 26 to 72 nm), EDX (peak at 3 keV), and zeta potential (- 15.76 ± 0.05 mV). The effect of silver nanoparticles by disc diffusion method (mm) is Enterococcus faecalis = 18.31 ± 0.35, Escherichia coli = 21.51 ± 0.61, and Staphylococcus aureus = 19.02 ± 1.28, and by MIC test (µg/ml), E. faecalis = 19, E. coli = 18, and Staphylococcus aureus = 16. Antibacterial activity of the silver nanoparticles synthesized from S. schtschegleevii means that these herbal nanoparticles treat urinary tract infections caused by some of the test isolates.

Green synthesis of Superparamagnetic Iron Oxide and Silver Nanoparticles in Satureja hortensis Leave Extract: Evaluation of Antifungal Effects on Botryosphaeriaceae Species.

In recent years, green synthesis methods of metallic nanoparticles (MNPs) have been attractive because of the more facile, cheaper, and appropriate features associated with biomolecules in MNPs biosynthesis. This research represented an easy, fast, and environmentally friendly method to biosynthesis of superparamagnetic iron oxide nanoparticles (SPIONPs) and silver nanoparticles (AgNPs) by the Satureja hortensis leaf extract as stabilizer and reducer. The SPIONPs synthesized in co-precipitation method. The biosynthesized SPIONPs and AgNPs were studied their antifungal effects against three Botryosphaeriaceae plant pathogens, Botryosphaeria dothidea, Diplodia seriata, and Neofusicoccum parvum. UV-visible spectra (UV-Vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (Fe-SEM), energy-dispersive X-ray spectroscopy (EDX), and vibrating-sample magnetometer (VSM) analyses were used to evaluate the physicochemical properties and verify the formation of green synthesized SPIONPs and AgNPs. UV-Vis spectra revealed absorption peaks at 243 and 448 nm for SPIONs and 436 nm for AgNPs, respectively. Microscopic and XRD analysis showed that SPIONPs and AgNPs was found spherical in shape with an average particle size of SPIONPs and AgNPs 10 and 12 nm, respectively. The antifungal test against Botryosphaeriaceae species showed that SPIONPs and AgNPs possess antifungal properties against B. dothidea, D. seriata, and N. parvum. However, AgNPs exhibits greater antifungal activity than SPIONPs. The results of the cytotoxicity tests of SPIONs and AgNPs on the MCF-7 cell line showed that AgNPs was significantly more cytotoxic towards the MCF-7 cell line, whereas no significant cytotoxic effect was recorded by SPIONs. Therefore, these biosynthesized MNPs could be substituted for toxic fungicides that are extensively applied in agriculture and contribute to environmental health and food safety.

Bactericidal Effect and Cytotoxicity of Graphene Oxide/Silver Nanocomposites.

To tackle the proliferation of pathogenic microorganisms without relying on antibiotics, innovative materials boasting antimicrobial properties have been engineered. This study focuses on the development of graphene oxide/silver (GO/Ag) nanocomposites, derived from partially reduced graphene oxide adorned with silver nanoparticles. Various nanocomposites with different amounts of silver (GO/Ag-1, GO/Ag-2, GO/Ag-3, and GO/Ag-4) were synthesized, and their antibacterial efficacy was systematically studied. The silver nanoparticles were uniformly deposited on the partially reduced graphene oxide surface, exhibiting spherical morphologies with an average size of 25 nm. The nanocomposites displayed potent antibacterial properties against both gram-positive bacteria (S. aureus and B. subtilis) and gram-negative bacteria (E. coli and S. enterica) as confirmed by minimum inhibition concentration (MIC) studies and time-dependent experiments. The optimal MIC for Gram-positive bacteria was 62.5 µg/mL and for Gram-negative bacteria was 125 µg/mL for the GO/Ag nanocomposites. Bacterial cells that encountered the nanocomposite films exhibited significantly greater inhibitory effects compared to those exposed to conventional antibacterial materials. Furthermore, the cytotoxicity of these nanocomposites was assessed using human epithelial cells (HEC), revealing that GO/Ag-1 and GO/Ag-2 exhibited lower toxicity levels toward HEC and remained compatible even at higher dilution rates. This study underscores the potential of GO/Ag-based nanocomposites as versatile materials for antibacterial applications, particularly as biocompatible wound dressings, offering promising prospects for wound healing and infection control.

Plant-Assisted Synthesis of Ag-Based Nanoparticles on Cotton: Antimicrobial and Cytotoxicity Studies.

The syntheses of Ag-based nanoparticles (NPs) with the assistance of plant extracts have been shown to be environmentally benign and cost-effective alternatives to conventional chemical syntheses. This study discusses the application of Paliurus spina-christi, Juglans regia, Humulus lupulus, and Sambucus nigra leaf extracts for in situ synthesis of Ag-based NPs on cotton fabric modified with citric acid. The presence of NPs with an average size ranging from 57 to 99 nm on the fiber surface was confirmed by FESEM. XPS analysis indicated that metallic (Ag0) and/or ionic silver (Ag2O and AgO) appeared on the surface of the modified cotton. The chemical composition, size, shape, and amounts of synthesized NPs were strongly dependent on the applied plant extract. All fabricated nanocomposites exhibited excellent antifungal activity against yeast Candida albicans. Antibacterial activity was significantly stronger against Gram-positive bacteria Staphylococcus aureus than Gram-negative bacteria Escherichia coli. In addition, 99% of silver was retained on the samples after 24 h of contact with physiological saline solution, implying a high stability of nanoparticles. Cytotoxic activity towards HaCaT and MRC5 cells was only observed for the sample synthetized in the presence of H. lupulus extract. Excellent antimicrobial activity and non-cytotoxicity make the developed composites efficient candidates for medicinal applications.

Plackett-Burman screening of physico-chemical variables affecting Citrus peel-mediated synthesis of silver nanoparticles and their antimicrobial activity.

With the growing resistance of pathogenic microbes to traditional drugs, biogenic silver nanoparticles (SNPs) have recently drawn attention as potent antimicrobial agents. In the present study, SNPs synthesized with the aid of orange (Citrus sinensis) peel were engineered by screening variables affecting their properties via Plackett-Burman design. Among the variables screened (temperature, pH, shaking speed, incubation time, peel extract concentration, AgNO3 concentration and extract/AgNO3 volume ratio), pH was the only variable with significant effect on SNPs synthesis. Therefore, SNPs properties could be enhanced to possess highly regular shape with zeta size of 11.44 nm and zeta potential of - 23.7 mV. SNPs purified, capped and stabilized by cloud point extraction technique were then checked for their antimicrobial activity against Bacillus cereus, Listeria innocua, Listeria monocytogenes, Staphylococcus aureus, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhimurium and Candida albicans. The maximum antimicrobial activity of SNPs was recorded against E. coli, L. monocytogenes and C. albicans with clear zone diameter of 33.2, 31.8 and 31.7 mm, respectively. Based on minimum inhibition concentration and minimum bactericidal concentration of SNPs (300 mg/l) as well as their effect on respiratory chain dehydrogenases, cellular sugar leakage, protein leakage and lipid peroxidation of microbial cells, E. coli was the most affected. Scanning electron microscopy, protein banding and DNA fragmentation proved obvious ultrastructural and molecular alterations of E. coli treated with SNPs. Thus, biogenic SNPs with enhanced properties can be synthesized with the aid of Citrus peel; and such engineered nanoparticles can be used as potent antimicrobial drug against E. coli.

Biocontrol of multidrug resistant pathogens isolated from fish farms using silver nanoparticles combined with hydrogen peroxide insight to its modulatory effect.

This study was divided into two parts. The first part involved the isolation, and detection of the prevalence and antimicrobial resistance profile of Aeromonas hydrophila, Pseudomonas aeruginosa, and Vibrio species from Nile tilapia fish and marine aquatic water. One hundred freshly dead Nile tilapia fish were collected from freshwater aquaculture fish farms located in Al-Abbassah district, Sharkia Governorate, and 100 samples of marine aquatic water were collected from fish farms in Port Said. The second part of the study focused on determining the in vitro inhibitory effect of dual-combination of AgNPs-H2O2 on bacterial growth and its down regulatory effect on crucial virulence factors using RT-PCR. The highest levels of A. hydrophila and P. aeruginosa were detected in 43%, and 34% of Nile tilapia fish samples, respectively. Meanwhile, the highest level of Vibrio species was found in 37% of marine water samples. Additionally, most of the isolated A. hydrophila, P. aeruginosa and Vibrio species exhibited a multi-drug resistance profile. The MIC and MBC results indicated a bactericidal effect of AgNPs-H2O2. Furthermore, a transcriptional modulation effect of AgNPs-H2O2 on the virulence-associated genes resulted in a significant down-regulation of aerA, exoU, and trh genes in A. hydrophila, P. aeruginosa, and Vibrio spp., respectively. The findings of this study suggest the effectiveness of AgNPs-H2O2 against drug resistant pathogens related to aquaculture.

Probiotic-derived silver nanoparticles target mTOR/MMP-9/BCL-2/dependent AMPK activation for hepatic cancer treatment.

Recent advances in nanotechnology have offered novel ways to combat cancer. By utilizing the reducing capabilities of Lactobacillus acidophilus, silver nanoparticles (AgNPs) are synthesized. The anti-cancer properties of AgNPs have been demonstrated in previous studies against several cancer cell lines; it has been hypothesized that these compounds might inhibit AMPK/mTOR signalling and BCL-2 expression. Consequently, the current research used both in vitro and in silico approaches to study whether Lactobacillus acidophilus AgNPs could inhibit cell proliferation autophagy and promote apoptosis in HepG2 cells. The isolated strain was identified as Lactobacillus acidophilus strain RBIM based on 16 s rRNA gene analysis. Based on our research findings, it has been observed that this particular strain can generate increased quantities of AgNPs when subjected to optimal growing conditions. The presence of silanols, carboxylates, phosphonates, and siloxanes on the surface of AgNPs was confirmed using FTIR analysis. AgNPs were configured using UV-visible spectroscopy at 425 nm. In contrast, it was observed that apoptotic cells exhibited orange-coloured bodies due to cellular shrinkage and blebbing initiated by AgNP treatment, compared to non-apoptotic cells. It is worth mentioning that AgNPs exhibited remarkable selectivity in inducing cell death, specifically in HepG2 cells, unlike normal WI-38 cells. The half-maximum inhibitory concentration (IC50) values for HepG2 and WI-38 cells were 4.217 µg/ml and 154.1 µg/ml, respectively. AgNPs induce an upregulation in the synthesis of inflammation-associated cytokines, including (TNF-α and IL-33), within HepG2 cells. AgNPs co-treatment led to higher glutathione levels and activating pro-autophagic genes such as AMPK.Additionally, it resulted in the suppression of mTOR, MMP-9, BCL-2, and α-SMA gene expression. The docking experiments suggest that the binding of AgNPs to the active site of the AMPK enzyme leads to inhibiting its activity. The inhibition of AMPK ultimately results in the suppression of the mechanistic mTOR and triggers apoptosis in HepG2 cells. In conclusion, the results of our study indicate that the utilization of AgNPs may represent a viable strategy for the eradication of liver cancerous cells through the activation of apoptosis and the enhancement of immune system reactions.

The Protective Effects of Vanillic Acid and Vanillic Acid-Coated Silver Nanoparticles (AgNPs) in Streptozotocin-Induced Diabetic Rats.

The production of nanoparticles enhances the bioactivity of biological molecules for drug delivery to diseased sites. This study explains how silver nanoparticle (AgNP) coating enhanced the protection effects of vanillic acid in male diabetic rats with streptozotocin- (STZ-) induced diabetes. Twenty-four rats were divided into four groups (n = 6) for this investigation. The first group (G1) is untreated, whereas diabetes was induced in the other three groups through STZ injection. Diabetic rats that were not getting therapy were included in the second group (G2, STZ-positive), whereas the other diabetic rats were divided into the third group (G3, vanillic acid-treated) and the fourth group (G4, vanillic acid-coated AgNPs treated). The treatment lasted four weeks. In G2, the induction of diabetes significantly (at P = 0.05) increased in serum glucose, glycated proteins, renal indices, interleukin-6 (IL-6), K+, immunoglobulins, and lipid peroxidation, while decreased Ca++, Na+, and other antioxidants in the kidney tissue homogenate. In addition, pathological altered signs were present in the pancreas and kidneys of diabetic rats. The renal and pancreatic tissues were effectively enhanced by vanillic acid or vanillic acid-coated AgNPs, bringing them very close to their prediabetic conditions. Vanillic acid-coated AgNPs offered a stronger defense against STZ-induced diabetes and lessened the effects of hyperglycemia compared to ordinary vanillic acid. Additionally, using vanillic acid coated with silver nanoparticles greatly increased the antioxidant and antidiabetic activity and reduced inflammation when compared to using vanillic acid alone.

Bacteria-mediated green synthesis of silver nanoparticles and their antifungal potentials against Aspergillus flavus.

The best biocontroller Bacillus subtilis produced silver nanoparticles (AgNPs) with a spherical form and a 62 nm size through green synthesis. Using UV-vis spectroscopy, PSA, and zeta potential analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy, the properties of synthesized silver nanoparticles were determined. Silver nanoparticles were tested for their antifungicidal efficacy against the most virulent isolate of the Aspergillus flavus fungus, JAM-JKB-BHA-GG20, and among the 10 different treatments, the treatment T6 [PDA + 1 ml of NP (19: 1)] + Pathogen was shown to be extremely significant (82.53%). TG-51 and GG-22 were found to be the most sensitive groundnut varieties after 5 and 10 days of LC-MS QTOF infection when 25 different groundnut varieties were screened using the most toxic Aspergillus flavus isolate JAM- JKB-BHA-GG20, respectively. In this research, the most susceptible groundnut cultivar, designated GG-22, was tested. Because less aflatoxin (1651.15 g.kg-1) was observed, treatment T8 (Seed + Pathogen + 2 ml silver nanoparticles) was determined to be much more effective. The treated samples were examined by Inductively Coupled Plasma Mass Spectrometry for the detection of metal ions and the fungicide carbendazim. Ag particles (0.8 g/g-1) and the fungicide carbendazim (0.025 g/g-1) were found during Inductively Coupled Plasma Mass Spectrometry analysis below detectable levels. To protect plants against the invasion of fungal pathogens, environmentally friendly green silver nanoparticle antagonists with antifungal properties were able to prevent the synthesis of mycotoxin by up to 82.53%.

Silver Coordination Polymers Driven by Adamantoid Blocks for Advanced Antiviral and Antibacterial Biomaterials.

The development of sustainable biomaterials and surfaces to prevent the accumulation and proliferation of viruses and bacteria is highly demanded in healthcare areas. This study describes the assembly and full characterization of two new bioactive silver(I) coordination polymers (CPs) formulated as [Ag(aca)(µ-PTA)]n·5nH2O (1) and [Ag2(µ-ada)(µ3-PTA)2]n·4nH2O (2). These products were generated by exploiting a heteroleptic approach based on the use of two different adamantoid building blocks, namely 1,3,5-triaza-7-phosphaadamantane (PTA) and 1-adamantanecarboxylic (Haca) or 1,3-adamantanedicarboxylic (H2ada) acids, resulting in the assembly of 1D (1) and 3D (2). Antiviral, antibacterial, and antifungal properties of the obtained compounds were investigated in detail, followed by their incorporation as bioactive dopants (1 wt %) into hybrid biopolymers based on acid-hydrolyzed starch polymer (AHSP). The resulting materials, formulated as 1@AHSP and 2@AHSP, also featured (i) an exceptional antiviral activity against herpes simplex virus type 1 and human adenovirus (HAd-5) and (ii) a remarkable antibacterial activity against Gram-negative bacteria. Docking experiments, interaction with human serum albumin, mass spectrometry, and antioxidation studies provided insights into the mechanism of antimicrobial action. By reporting these new silver CPs driven by adamantoid building blocks and the derived starch-based materials, this study endows a facile approach to access biopolymers and interfaces capable of preventing and reducing the proliferation of a broad spectrum of different microorganisms, including bacteria, fungi, and viruses.

Rosmarinic Acid-Rich Perilla frutescens Extract-Derived Silver Nanoparticles: A Green Synthesis Approach for Multifunctional Biomedical Applications including Antibacterial, Antioxidant, and Anticancer Activities.

This study describes a simple, cost-effective, and eco-friendly method for synthesizing silver nanoparticles using a rosmarinic acid extract from Perilla frutescens (PFRAE) as the bioreduction agent. The resulting nanoparticles, called PFRAE-AgNPs, were characterized using various analytical techniques. The UV-Vis spectrum confirmed the formation of PFRAE-AgNPs, and the FTIR spectrum indicated the participation of rosmarinic acid in their synthesis and stabilization. The XRD pattern revealed the crystal structure of PFRAE-AgNPs, and the TEM analysis showed their spherical morphology with sizes ranging between 20 and 80 nm. The DLS analysis indicated that PFRAE-AgNPs were monodispersed with an average diameter of 44.0 ± 3.2 nm, and the high negative zeta potential (-19.65 mV) indicated their high stability. In the antibacterial assays, the PFRAE-AgNPs showed potent activity against both Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial pathogens, suggesting that they could be used as a potential antibacterial agent in the clinical setting. Moreover, the antioxidant activity of PFRAE-AgNPs against DPPH and ABTS radical scavengers highlights their potential in the treatment of various oxidative stress-related diseases. PFRAE-AgNPs also demonstrated significant anticancer activity against a range of cell lines including human colon cancer (COLO205), human prostate carcinoma (PC-3), human lung adenocarcinoma (A549), and human ovarian cancer (SKOV3) cell lines suggesting their potential in cancer therapy. The nanoparticles may also have potential in drug delivery, as their small size and high stability could enable them to cross biological barriers and deliver drugs to specific target sites. In addition to the aforementioned properties, PFRAE-AgNPs were found to be biocompatible towards normal (CHO) cells, which is a crucial characteristic for their application in cancer therapy and drug delivery systems. Their antibacterial, antioxidant, and anticancer properties make them promising candidates for the development of new therapeutic agents. Furthermore, their small size, high stability, and biocompatibility could enable them to be used in drug delivery systems to enhance drug efficacy and reduce side effects.

Silver nanoparticles in plant health: Physiological response to phytotoxicity and oxidative stress.

Silver nanoparticles (AgNPs) have gained significant attention in various fields due to their unique properties, but their release into the environment has raised concerns about their environmental and biological impacts. Silver nanoparticles can enter plants following their exposure to roots or via stomata following foliar exposure. Upon penetrating the plant cells, AgNPs interact with cellular components and alter physiological and biochemical processes. One of the key concerns associated with plant exposure to AgNPs is the potential of these materials to induce oxidative stress. Silver nanoparticles can also suppress plant growth and development by disrupting essential plant physiological processes, such as photosynthesis, nutrient uptake, water transport, and hormonal regulation. In crop plants, these disruptions may, in turn, affect the productivity and quality of the harvested components and therefore represent a potential threat to agricultural productivity and ecosystem stability. Understanding the phytotoxic effects of AgNPs is crucial for assessing their environmental implications and guiding the development of safe nanomaterials. By delving into the phytotoxic effects of AgNPs, this review contributes to the existing knowledge regarding their environmental risks and promotes the advancement of sustainable nanotechnological practices.

Broad-spectrum nano-bactericide utilizing antimicrobial peptides and bimetallic Cu-Ag nanoparticles anchored onto multiwalled carbon nanotubes for sustained protection against persistent bacterial pathogens in crops.

Worldwide crop yields are threatened by persistent pathogenic bacteria that cause significant damage and jeopardize global food security. Chemical pesticides have shown limited effectiveness in protecting crops from severe yield loss. To address this obstacle, there is a growing need to develop environmentally friendly bactericides with broad-spectrum and sustained protection against persistent crop pathogens. Here, we present a method for preparing a nanocomposite that combines antimicrobial peptides (AMPs) and bimetallic Cu-Ag nanoparticles anchored onto multiwalled carbon nanotubes (MWCNTs). The nanocomposite exhibited dual antibacterial activity by disrupting bacterial cell membranes and splicing nucleic acids. By functionalizing MWCNTs with small AMPs (sAMPs), we achieved enhanced stability and penetration of the nanocomposite, and improved loading capacity of the Cu-Ag nanoparticles. The synthesized MWCNTs&CuNCs@AgNPs@P nanocomposites demonstrated broad-spectrum lethality against both Gram-positive and Gram-negative bacterial pathogens. Glasshouse pot trials confirmed the efficacy of the nanocomposites in protecting rice crops against bacterial leaf blight and tomato crops against bacterial wilt. These findings highlight the excellent antibacterial properties of the MWCNTs&CuNCs@AgNPs@P nanocomposite and its potential to replace chemical pesticides, offering significant advantages for agricultural applications.

Wound Dressing Based on Silver Nanoparticle Embedded Wool Keratin Electrospun Nanofibers Deposited on Cotton Fabric: Preparation, Characterization, Antimicrobial Activity, and Cytocompatibility.

Wool keratin (WK) protein is attractive for wound dressing and biomedical applications due to its excellent biodegradability, cytocompatibility, and wound-healing properties. In this work, WK-based wound dressings were prepared by depositing WK/poly(vinyl alcohol) (PVA) and silver nanoparticle (Ag NP)-embedded WK/PVA composite nanofibrous membranes on cotton fabrics by electrospinning. Ag NPs were biosynthesized by reduction and stabilization with sodium alginate. The formed Ag NPs were characterized by ultraviolet-visible and Fourier transform infrared (FTIR) spectroscopy, and their size was determined by transmission electron microscopy and image analysis. The formed Ag NPs were spherical and had an average diameter of 9.95 nm. The produced Ag NP-embedded WK/PVA composite nanofiber-deposited cotton fabric surface was characterized by FTIR and dynamic contact angle measurements, and the nanofiber morphologies were characterized by scanning electron microscopy. The average diameter of the nanofibers formed by 0.1% Ag NP-embedded WK/PVA solution was 146.7 nm. The antibacterial activity of the surface of cotton fabrics coated with electrospun composite nanofibers was evaluated against the two most common wound-causing pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. The cotton fabric coated with 0.1% Ag NP-embedded WK/PVA nanofibers showed very good antibacterial activity against both pathogens, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed good cytocompatibility against L-929 mouse fibroblast cells. However, the increase in Ag NP content in the nanofibers to 0.2% negatively affected the cell viability due to the high release rate of Ag ions. The results achieved show that the developed wound dressing has good potential for wound healing applications.